Obstructive sleep apnea (OSA), a heterogeneous and multifactorial sleep related breathing disorder with high prevalence, is a recognized risk factor for cardiovascular morbidity and mortality. Autonomic dysfunction leads to adverse cardiovascular outcomes in diverse pathways. Heart rate is a complex physiological process involving neurovisceral networks and relative regulatory mechanisms such as thermoregulation, renin-angiotensin-aldosterone mechanisms, and metabolic mechanisms. Heart rate variability (HRV) is considered as a reliable and non-invasive measure of autonomic modulation response and adaptation to endogenous and exogenous stimuli. HRV measures may add a new dimension to help understand the interplay between cardiac and nervous system involvement in OSA. The aim of this review is to introduce the various applications of HRV in different aspects of OSA to examine the impaired neuro-cardiac modulation. More specifically, the topics covered include: HRV time windows, sleep staging, arousal, sleepiness, hypoxia, mental illness, and mortality and morbidity. All of these aspects show pathways in the clinical implementation of HRV to screen, diagnose, classify, and predict patients as a reasonable and more convenient alternative to current measures. It is outflow . Previou outflow .Currently, HRV analysis, including time-domain, frequency-domain, and non-linear analysis, is used to explore the activities of sympathetic and parasympathetic nervous systems , 10. TimHeart rate and blood pressure oscillations are characterized by parasympathetic predominance and sympathetic inhibition in normal subjects during non-rapid eye movement (NREM) sleep . In contTaken together, HRV could provide a static and a dynamic perspective to observe the changes in connectivity between central and cardiac autonomic modulation during sleep and its persistent influence during daytime. This review focuses on neuro-cardiac autonomic regulatory mechanisms and the multifaceted applications of HRV in OSA as a potential additional clinical diagnostic tool.HRV is usually measured over a short-term (5–15 min) or long-term period (1–24 h). Long-term measurements are generally used to assess mortality and adverse prognosis of patients, but short-term measurements have been shown to be sufficiently stable and applicable for screening. However, 5-min recordings only had strong correlation with HF . Li et aMost studies use short-term time windows with their analytic techniques; 2–5 min with Fast Fourier Transform (FFT) or autoregression, or 1–2 min with multiple trigonometric regressive spectral (MTRS) analysis , 38, 39.Longer time windows are commonly analyzed with FFT or autoregression, as they are commonly divided into 1–5-min periods and averaged to provide a mean for the total time segment , 36, 37.via long-term analysis. Many studies assessing mortality have used overnight or 24-h HRV analyses to obtain a reliable prognosis and use 5-min windows within these time periods to compare HRV , sleep is categorized into non-rapid eye movement (NREM) stages N1, N2, N3, into stage rapid eye movement sleep (REM), and into stage Wake by visual electroencephalogram (EEG), electrooculogram (EOG), and chin electromyogram (EMG) scoring . CollectOSA seems to have long-term effect on HRV even during wakefulness with the absence of sleep apnea. Limited data regarding its underlying mechanisms during daytime or ambulatory wake state is reported. It is assumed that autonomic dysfunction plays a key role in persistent OSA related outcomes, leading to a blunted diurnal HRV pattern. Using 10-min ECG segments and muscle sympathetic nerve activity (MSNA) recordings during daytime, Narkiewicz et al. found that the magnitude of cardiovascular variability is associated with the severity of OSA. There was reduced RR variance, increased sympathetic tone and decreased parasympathetic tone in moderate-to-severe OSA populations compared to matched controls . Balachavia increased LF and LF/HF parameters in HRV.The normalizing effect of OSA therapy on HRV during sleep has also been suggested. Earlier studies report higher sympathetic activity during wake and sleep, but this has normalized, perhaps because of CPAP , 85. Thivia HRV with 100% accuracy when comparing to normal subjects and 90% when comparing normal and apneic minute intervals in 35 samples. Roche et al.  and nCPAP responsive objective sleepiness (r = 0.44), suggesting autonomic arousal detection should be taken into account as a sleep fragmentation index to quantify sleepiness. Bartels et al. tried to define autonomic arousal. They found that lower blood pressure and high heart rate in the 15-s window before short-term cortical arousal and cardiovascular changes shift in the opposite direction after sleep recovery  in OSA varies from 19 to 87.2% –134. HowHowever, some studies show that ESS increases with the severity of OSA , 137. EDThere is little doubt that attentional deficits affect driving capacity. Detection of drowsiness is importance in order to prevent road accidents due to SDB related sleepiness . Chua etIt has been shown that sleepy OSA patients have a higher prevalence of adverse cardiovascular outcomes  than non-sleepy OSA patients . FurtherPrevious studies have proven that CPAP could reduce daytime sleepiness . Less beExposure to hypoxia is a leading cause of oxidative stress, inflammation, and sympathetic hyperactivity . RecurreOSA generally generates a decrease in HRV during normobaric hypoxia in most reported investigations. However, there are still underlying complex central-peripheral interactions and modulation pathways in vulnerable populations. To address those issues, a growing body of studies have attempted to investigate the hypoxia burden in OSA –161. TimThe possibility of an increasing risk in the mortality and morbidity in hypoxic OSA patients with autonomic dysfunction requires further evidence. In addition, both hypoxia and arousal have confounding effects on respiratory-cardiac coupling. Which one is the determinant of cardiac autonomic dysfunction in OSA is controversial in animal and human studies . It seemSome studies indicated that certain damages of autonomic function are reversible after eliminating physiological influences  in OSA population with CPAP treatment , 168. ThOSA affects 0.1–13% of children, particularly occurred in pre-school age . PediatrPrevious studies have demonstrated age-, ethnicity-, and sex-specific differences in HRV in the healthy general population and under certain conditions. It is generally accepted there is an inverse association between age and HRV. However, it is unclear whether the effects of OSA on cardiac autonomic modulation in elderly subjects (>60 yr) are different from those in other age groups (young and mid-aged adults). Trimer et al. compared the differences in HRV among the elderly and the young population with and without OSA. They found the elderly with OSA have significantly lower LF/HF ratio only during wakefulness at night than the young with OSA but not during other sleep stages . Sforza Findings on sex and ethnic differences in HRV are less consistent . NonetheIn terms of interaction associations between HRV and age, sex, and ethnicity, Liao et al.  found chPsychophysiological disturbances have significant impacts on the autonomic nervous system (ANS) , 208–211via HRV analysis.Reduced global HRV is consistently reported in depression and anxiety disorders. Specifically, depression is characterized by increased cardiac rhythmicity and reduced heart rate variability during both sleep and wakefulness . MoreoveEvidence of autonomic dysfunction in OSA with various psychiatric and psychological disorders deepens the understanding of their psychopathology and physiopathology associated with negative cardiovascular outcomes. Correlation studies of OSA and neuropsychiatric diseases in ANS function assessed by HRV are lacking. Furthermore, it would be challenging to diagnose and treat co-morbid psychiatry disorders and OSA. It is known that the administration of drugs for psychiatric treatment aggravates OSA as it potentially reduces upper airway muscle tone to impair airway stability, decreases ventilatory response to hypoxia, increases arousal threshold leading to prolongation of respiratory events and deteriorates oxygen saturation. It seems that HRV analysis could be highly applicable in the exploration of the cardiovascular and psychopathological implications in psychiatric disorders. Investigations in the overlapping conditions in physiological and psychological aspects in OSA patients who have worse clinical outcomes and treatment response are warranted. Quintana et al.  provide Due to HRV being a marker of autonomic innervation of the heart, it has been suggested that increased sympathetic activity during sleep due to OSA may be a link to cardiovascular disease . SympathSeveral cardiovascular disease studies have reported an increased risk of mortality in relation to altered HRV parameters. Kleiger et al. found that a 24-h SDNN of <50 ms carried a relative risk of mortality 5.3 times higher than an SDNN of over 100 ms. They suggested that increased sympathetic or decreased vagal tone may predispose to VF . Zemaityvia CPAP, which is especially crucial in younger patients, as they carry a higher mortality risk.Additionally, CVD and OSA have been shown to be linked –234. TheIn the linking of OSA and CVD, HRV, and OSA mortality and mortality, the exact physiological pathway through which these are connected is not well-understood. In animal models, Iturriaga  proposedHowever, despite the clear association between OSA and mortality and CVD, more studies need to be done to determine the exact physiological mechanisms by which this occurs, and if OSA is an independent causal factor of increased mortality and CVD risk as suggested. From the current data, altered HRV features such as SDNN are good predictors of cardiovascular mortality. There appears to be a correlation of higher mortality risk and lower SDNN, but the cut-off point varies depending on the populations and the length of ECG segments. Therefore, determination of a clear cut-off value of SDNN requires further investigation .With more sophisticated analytical approaches and techniques developing, HRV measures could provide additional electrophysiological information on impaired cardiovascular alternation, which might be related to subclinical cardiovascular outcomes in patients with OSA. It is already known that the determination of time window (ECG segment length and SDB-related events) is critical to HRV analysis, but a standardized analytical approach is lacking. HRV is proving to be accurate in sleep staging and particularly screening and diagnosing OSA. However, a combinatorial method of HRV and EDR provides hidden information on cardiopulmonary coupling, which transfers from heart rate to respiration and improves the accuracy of sleep apnea detection compared to either method alone. The cognitive consequences and the daytime outcomes of ANS alternation during sleep in patients with OSA are unclear. The use of HRV in the prognosis of OSA independent of CVD is also unclear. However, HRV has shown a close association to mortality and co-morbidities. Additionally, overlapping conditions increase progressively in OSA, requiring reliable tools to manage those conditions at an early stage. Further studies are required to explore the implications of integrated cardiac physiology in regulatory networks between the central brain and heart. In particular, following this investigation, several research topics have been found to be of value:Prospective studies using HRV to accurately predict cardiovascular outcomes in OSA should be as a priority for clinical application of HRV researchStudies investigating cardiac OSA phenotypes on the basis of HRV profiles to facilitate the definition of OSA subtypes and implement tailored treatment approaches in clinical practiceNew sophisticated methods of HRV analysis to analyze the inevitable instationarities of OSA's transitional nature that prove challenging for current algorithms and modelsContext-dependent analyses of HRV  to better understand the association between anthropometric and sleep characteristics and autonomic function in OSAInvestigation and standardization of the time window segments analyzed to provide comparable and valuable ECG data in OSA during an overnight sleep studyHRV is showing promise in clinical application and due to the already large and increasing prevalence of OSA, these further studies are imperative to the advancement of diagnostic and treatment approaches needed to minimize the existing and future health and financial burden.HQ and TP were responsible for the manuscript concept and design. HQ, NS, and TP prepared the manuscript draft. JFK prepared the figures. HQ, NS, TP, MG, NW, JFK, and FV-V contributed to critical revision of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


In 2020, 55 million people worldwide were living with dementia, and this number is projected to reach 139 million in 2050. However, approximately 75% of people living with dementia have not received a formal diagnosis. Hence, they do not have access to treatment and care. Without effective treatment in the foreseeable future, it is essential to focus on modifiable risk factors and early intervention. Central auditory processing is impaired in people diagnosed with Alzheimer’s disease (AD) and its preclinical stages and may manifest many years before clinical diagnosis. This study systematically reviewed central auditory processing function in AD and its preclinical stages using behavioural central auditory processing tests. Eleven studies met the full inclusion criteria, and seven were included in the meta-analyses. The results revealed that those with mild cognitive impairment perform significantly worse than healthy controls within channel adaptive tests of temporal response (ATTR), time-compressed speech test (TCS), Dichotic Digits Test (DDT), Dichotic Sentence Identification (DSI), Speech in Noise (SPIN), and Synthetic Sentence Identification-Ipsilateral Competing Message (SSI-ICM) central auditory processing tests. In addition, this analysis indicates that participants with AD performed significantly worse than healthy controls in DDT, DSI, and SSI-ICM tasks. Clinical implications are discussed in detail. Globally, 55 million people were estimated to be living with dementia in 2020 . With thApproximately 40% of dementia diagnoses could be prevented or delayed by modifying early life (education), midlife , and later life  risk factors . Of the There are two main components of the auditory system: the peripheral system and the central auditory system ,10. The In current clinical practice, brain imaging techniques such as structural neuroimaging with magnetic resonance imaging (MRI) and molecular neuroimaging with positron emission tomography (PET) are used to support the diagnosis of AD ,21. Due Given the higher prevalence of peripheral hearing loss in older adults, it is vital to establish the impact of peripheral hearing impairment in age-related CAP impairment. The central auditory pathway undergoes pathophysiological changes due to healthy ageing, i.e., a decline in temporal lobe volume , hippocaThe purpose of this paper was to systematically review currently available literature that examines the behavioural central auditory assessments of individuals aged 40–85 years to determine (i) challenges about selection and administration of behavioural central auditory processing assessments to those with impaired cognitive and/or daily living functions, (ii) modifications to the standard central hearing assessment procedures to accommodate impaired cognitive and/or daily living functions, and (iii) the factors that influence the interpretation of test results. Two research questions were investigated: (i) What are the most commonly utilised behavioural central auditory processing tests for older adults diagnosed with AD or in preclinical stages, and which are the most sensitive? (ii) What are the limitations of these measures, and how can they be improved? The primary objective is to identify a CAP assessment/test battery that is accurate and is a sensitive early detection tool for AD. This systematic review will contribute to understanding the strengths and limitations of behavioural central auditory function assessments in individuals with AD and those at risk of developing AD. It may also aid in identifying a method for early AD detection. At-risk individuals could be effectively screened and better referred for further neuropsychological assessments.The methodological approach for this review is outlined in detail in the review protocol . MethodsThe studies included in this review evaluated 16 different behavioural central auditory assessments. Five studies used the synthetic sentence identification-ipsilateral competing message (SSI-ICM) test and the dichotic digits test (DDT) to evaluate central auditory function. Four studies used the dichotic sentence identification test (DSI), and three used the speech perception in noise test (SPIN). Adaptive tests of temporal response (ATTR), time-compressed speech test (TCS), auditory fusion test (AFT), auditory memory battery of Goldman–Fristoe–Woodcock (GFW), pitch pattern sequence (PPS), and the gap-in-noise (GIN) test were each evaluated in two studies to assess central auditory function. Synthetic sentence identification-competitive contralateral message (SSI-CCM), tone duration discrimination (TDD), speech in Babble (SinB), random gap detection test (RGDT), selective auditory attention test (SAAT), Quick Speech-in-Noise (QuickSIN), and duration pattern test (DPT) were each used in one study to assess central auditory functionI2, values from 0% to 40% were considered low heterogeneity, 41% to 60% moderate, and >61% highly heterogeneous [Multiple central auditory processing tests were assessed on the basis of the pooled data of the studies included in the review. Meta-analyses were conducted on temporal auditory processing tests (ATF and ATTR), dichotic tests (DDT and DSI), and monaural low-redundancy speech tests . The results of the meta-analyses are reported as the standard difference in mean (SMD) with 95% confidence intervals (CI) as the synthesised measure of effect size. Heterogeneity was tested using Cochrane’s Q-value statistic, and the I-squared . Pooled analysis of ATF studies indicated that although there was moderate effect size, there was no significant difference between MCI participants and controls in mean ATF scores, pooled SMD, 0.55 ; however, between the AD group and controls, there was no significant heterogeneity (p = 0.254).In comparison to controls, participants with MCI performed seven deviations below the mean in DDT (z = −7.23), with a significantly large effect size, pooled SMD, −0.87 . There was no heterogeneity across studies in the analysis of any of the monaural low-redundancy speech tests except for MCI studies on SSI-ICM (p = 0.000)  were rated “moderate”, and one was rated “weak”. None of the 13 studies included met all the core components of the quality assessment, which can be attributed to the absence of information or lack of clarity refer to . None ofThis systematic review and meta-analysis aimed to review studies that examine central auditory processing function in AD and its preclinical stages using behavioural central auditory processing tests. Meta-analyses were conducted on temporal auditory processing tests (ATF and ATTR), dichotic tests (DDT and DSI), and monaural low-redundancy speech tests . Results from this investigation suggest that participants with MCI performed significantly worse than healthy controls within channel ATTR, DDT, DSI, SPIN, SSI-ICM, and TCS central auditory processing tests. In addition, this analysis indicates that participants with AD performed significantly worse than healthy controls in DDT, DSI, and SSI-ICM central auditory processing assessments.Temporal auditory processing refers to the perception and processing of sound or the changes of durational characteristics of sound within a particular time interval . The abiA limited number of studies investigated GIN, RGDT, and PPS in participants with cognitive impairment. Therefore, pooled analysis was not possible. This could be attributed to the complexity of these behavioural tests and the difficulty to perform in people with cognitive impairment. These tests require complex responses from the individuals performing the test and require substantial attention, understanding, and participation, limiting their use and reliability in people with moderate-to-severe cognitive impairment.Dichotic listening tasks are suggested to involve cognitive processes such as memory and attention. Several neuroimaging studies show frontal, temporal, and parietal lobe activation when performing these tasks ,61,62, iIn addition, DSI performance has also been related to cortical thickness in the inferior gyrus and auditory transverse and superior temporal gyri, which are involved in language and auditory function . In addiParticipants with AD often have impaired executive functions, resulting in an inability to respond accurately in the dichotic listening task when instructed to focus attention on a particular ear ,72,73. MThe findings in this meta-analysis indicate that SSI-ICM performance is impaired in participants with MCI and AD. It has been previously demonstrated that the SSI-ICM score is associated with parahippocampal gyrus and entorhinal cortical thickness, regions susceptible to atrophy in pre-symptomatic stages of AD . In addiDeficient speech perception in noise has been suggested to be associated with decreased neural synchrony, which in turn leads to impaired processing of timing information in noise . The temPooled analysis was not possible for auditory memory tests due to the limited number of studies that included GFW in the test battery for participants with MCI and AD. One study showed that recognition memory, auditory memory for content, and auditory memory for sequence were all significantly impaired in participants with MCI compared to healthy age-matched controls when using the GFW test battery . The GFWSimilarly, this review was unable to assess tone duration discrimination due to the limited number of studies that used this test in participants with cognitive impairment. TDD has been previously demonstrated to be impaired in participants with AD compared to healthy controls . The pooDue to aging, pathophysiological changes occur in the peripheral and central auditory systems . SeveralThe ‘central effects of peripheral pathology’ (CEPP) hypothesis argues that the pathophysiological changes in the central auditory pathway result from peripheral hearing impairment . CEPP coSuppose the CAP impairment is due to CEPP. In that case, the first solution should be providing suitable amplification devices to remedy the peripheral hearing pathology, such as hearables, hearing aids, or hearing implants. Suppose the CAP impairment is due to CEBA with no peripheral impairment yet causing challenges in speech understanding in background noise. In that case, personal assistive listening devices such as hearing loop (or induction loop) systems, FM systems, infrared systems, amplified telephones, notification systems, personal amplifiers, TV streamers, and captions could help deal with background noise. Further auditory training to help discriminate between tones, noises, digits or speech sounds, sound localisation, or focus on other hearing-related skills could also be helpful .There are several limitations in conducting CAP testing with older adults in clinical settings. CAP testing cannot be performed in older adults with moderately severe-to-profound sensorineural hearing loss. Even less severe peripheral hearing loss can affect CAP testing results, mainly when testing speech discrimination in the presence of background noise. This is further complicated as binaural separation, binaural integration, and monaural tasks cannot be performed in the free field. Therefore, it is not possible for those who wear hearing aids or cochlear implants to use them while testing. Peripheral hearing loss can be mitigated by presenting tests at the client preferred level and using closed set testing such as DDT and SSI-ICM or tests such as DPT that are not dependent on speech discrimination. Future studies may conduct speech in noise testing, such as the SSI-ICM in the free field to wear hearing devices during testing.Additionally, the results can vary from one CAP test to another on the same person. Using a CAP test battery that assesses a multitude of auditory processing skills while considering peripheral hearing and cognitive loading will reflect the most accurate assessment of an individual’s auditory processing skills in clinical settings. However, it is vital to consider the length of the test battery to ensure that it is not too long; otherwise, results may be confounded by fatigue. Other health-related factors could affect test outcomes that can influence the test results, i.e., vision, physical, mental, and psychological. As the CAP testing requires active participation, it would be difficult to obtain reliable test results from those diagnosed with dementia. Incorporating electrophysiological test measures such as P300 could be helpful when assessing CAP impairment in older adults diagnosed with dementia.Many current studies compare mean scores of SCD, MCI, and AD groups to a healthy control group. However, to be able to develop a CAP assessment/test battery that is accurate and is a sensitive early detection tool for AD, further development needs to consider how a healthcare professional can implement the test battery on an individual when considering the fact that it is normal for individuals to fail some tasks in a CAP test battery. There has been much debate within the audiology profession about which CAP results constitute a CAP impairment diagnosis. This will be the same difficulty faced when developing a clinically implementable CAP battery as a screening tool for early indication of SCD, MCI, or AD.The outcomes of the auditory-verbal CAP test rely not only on factors related to cognition and hearing but also on linguistic factors. Therefore, fluency and accent can also impact the outcomes of these tests. Some of the auditory–verbal CAP tests are validated only in a few languages. Consequently, they cannot be used with non-native speakers.Few studies have investigated the central auditory processing functions of those diagnosed with AD. These central auditory processing tests are behavioural tests that are difficult to perform in people with AD, which could explain the limited number of studies with AD participants that look at central auditory processing using behavioural tests. Due to the limited number of studies that investigate CAP behavioural assessments in people with MCI compared to AD, this analysis was unable to examine whether any of these assessments can differentiate between participants with AD and MCI. This analysis indicated that MCI participants could be differentiated from healthy aged-matched controls on the basis of their performance on some of the behavioural CAP assessments. In conclusion, a subjective CAP test battery can be used as a hearing biomarker/clinical tool to early identify older adults at risk of cognitive impairment in clinical settings.


The coronavirus disease 2019 (COVID-19) pandemic and subsequent physical distancing recommendations created major gaps in traditional dermatologic undergraduate and postgraduate medical education delivery. Nevertheless, the educational consequences of various public health restrictions have indirectly set aside the inertia, resistance, and risk averse approach to pedagogical change in medicine. In Canada, rapid collaboration and innovation in dermatologic education has led to novel programs including the implementation of a range of internet-facilitated group learning activities and a dramatic expansion of digital telehealth and virtual care. Going forward, three key issues arising from these developments will need to be addressed: the ongoing assessment of these innovations for efficacy; sustaining the momentum and creativity that has been achieved; and, determining which of these activities are worth maintaining when traditional “tried and true” learning activities can be resumed. Herein, we highlight educational gaps created by COVID-19, innovative educational initiatives across Canada during the pandemic, and the future opportunities arising from this worldwide health crisis.The coronavirus disease 2019 (COVID-19) pandemic will profoundly impact undergraduate and postgraduate medical education for the foreseeable future, This is currently being led by the Specialty Committee in Dermatology for the Royal College of Physicians and Surgeons, with a plan for implementation in 2022.Post-graduate dermatology education across Canada has traditionally been rooted in supervised direct patient care and separate didactic sessions based on in-person participation at weekly academic half-day sessions, grand rounds, journal clubs and other group activities. The Royal College of Physicians and Surgeons recently mandated the evolution of resident learning and assessment toward a competency by design (CBD) model.The Canadian Professors of Dermatology (CPD) also sponsors two well-recognized national education programs through: (1) BoSS (Basics of Skin Science)—an in-person half-day lecture series for senior residents attending the Canadian Dermatology Association (CDA) annual meeting; and, (2) DRIVE (Dermatology Residents Innovation and Vision in Education)—a series of online lectures, practice written exam, and an in-person mock objective structured clinical exam (OSCE) conducted annually for final-year residents preparing for their specialist certification examination. In addition, regional, national, and international conferences have provided important annual opportunities for residents to learn from experts and present their research.Dermalogues, a resident-focused dermatology podcast. Other virtual and accredited programs for the broader dermatology community include the online CDA journal club, the Journal of Cutaneous Medicine and Surgery (JCMS) continuing medical education (CME) program consisting of self-assessment modules, and JCMS author podcasts.Prior to the COVID-19 pandemic, a few distance education resources were readily available. The CDA produced two seasons of COVID-19 has challenged the traditional delivery of postgraduate dermatology education primarily because of physical distancing measures mandated by public health authorities. This has dramatically reduced in-person clinical activities and didactic instruction in group settings. Likewise, professional and academic dermatology associations have cancelled their in-person meetings due to bans on large group gatherings and nonessential travel. While dermatology teaching is gradually increasing within medical school curricula, standardization of pre-clinical dermatology teaching has been suggested to facilitate comprehensive and consistent exposure.Undergraduate dermatology education currently exists in the form of pre-clinical teaching followed by clerkship rotations. In Canada, pre-clinical teaching currently represents approximately 75% of a medical student’s total exposure to dermatology, and its format and content varies across Canadian institutions.In response to COVID-19, pre-clinical activities have been transitioned to virtual settings and clerkship rotations across Canada were postponed for almost half a year, with an indefinite suspension of inter-university clinical electives. The intermediate or long-term effects of eliminating clinical encounters with dermatology patients and dermatological preceptors on medical student competency are unknown at this time. In addition, the elimination of inter-provincial electives may impact undergraduate students’ chances of matching to dermatology programs during the annual Canadian Residency Match Service (CaRMS). For the upcoming cycle, CaRMS interviews and socials will be completed entirely through virtual means across the country. At this stage, it is unclear how restrictions on electives or the use of virtual modalities for interviews will impact the ability of residency programs to assess candidates or vice-versa.This evolving health crisis has demanded flexibility from learners and educators, rapid innovation in education delivery, and collaboration among various stakeholders including the CDA, CPD, CDA Resident & Fellows Society (CDA-RFS), and program directors (PDs) responsible for post-graduate dermatology training across Canada. The current situation has been a forced opportunity to trial pedagogical changes, many of which were likely inevitable, on an accelerated timeline. It has ultimately spurred increased incorporation of virtual modalities into the continuum of clinical and didactic teaching. During the pandemic, telehealth in one form or another has been almost universal in order to maintain even basic levels of essential dermatologic care. Although the mode and extent have varied greatly among practices across Canada, dermatologists have been connecting with their patients through the exclusive or combined use of telephones, real time video, email, text messaging, and “conventional” store-and-forward telemedicine portals.COVID-19 has increased acceptance, uptake, and direct experiences with telehealth and virtual care in dermatology. While there are some limitations to its use, telehealth will be an upcoming focus for the CBD transition. From a teaching perspective, teledermatology has been established as an effective dermatologic education tool for both medical students and dermatology residents, as well as internal medicine and pediatric learners. During the first months of the pandemic, Oldenburg et al. proposed a 4-step method to optimize teledermatology visits for resident education. However, further validation of this approach is required. Based on the authors’ experiences, residents across Canada have been incorporated into teledermatology visits at varying rates and to varying degrees over the first half-year of the pandemic.Telehealth services have been identified as a possible ongoing core service delivery model for rural and remote communities.www.dermatology.ca).All postgraduate dermatology programs across the country have transitioned their weekly academic half-day sessions to online formats. The close-knit nature of the dermatology community across Canada has facilitated various educational endeavors on a national level. The CDA, CDA-RFS, CPD and PDs have proactively collaborated to establish novel educational initiatives through virtual modalities to support, encourage, and enhance resident learning . The rec; the National Procedural Dermatology Lecture Series has provided increased access to didactic teaching in this realm.The increasing acceptance of online platforms over the last few months has also accelerated projects that were already in-progress including the National Procedural Dermatology Lecture Series and National Junior Resident Bootcamp. Some of these initiatives have also concurrently responded to educational needs identified before the pandemic. For example, Worley et al. established a need for increased aesthetic dermatologic training in Canadian residency programsThe COVID-19 pandemic has ultimately necessitated a united national approach to curricular activities. This, in turn, has helped to equalize educational opportunities for residents across the country: residents now have increased and organized access to teaching by clinical experts whom they would otherwise not encounter. By uniting residents from coast to coast in educational pursuits, it has also undoubtedly contributed to increased social cohesion among the nascent future dermatology community. It will also remain to be seen whether residents retain the same information and knowledge as with in-person sessions.We recognize that these virtual initiatives do not replace traditional clinical teaching activities but rather are supplemental to them. In addition, there are associated barriers such as time constraints , limited infrastructure, and “Zoom fatigue,” a recently reported phenomenon of mental exhaustion associated with prolonged and repeated participation on video platforms.This global crisis provides an unprecedented opportunity to undertake seminal transformation in dermatologic education at the undergraduate and postgraduate level. A variety of possible avenues in the clinical, didactic, and research arenas is summarized in  With ongoing restrictions on medical school electives, telehealth may be an avenue for postgraduate dermatology residency programs to assess future CaRMS applicants.Some components of telehealth will become a permanent pillar of dermatologic care and resident education as we move forward. This would benefit from ongoing evaluation in its effectiveness for patient care and as a teaching tool. It may also provide fruitful and much needed learning opportunities for medical students, all of whom need even a basic level of clinical dermatology exposure. Loh et al. suggests an integrative approach in which residents lead virtual encounters while medical students observe. While initially spurred by the pandemic, the authors strongly believe that virtual learning will become a permanent instrument of our specialty’s educational armamentarium.E-learning tools have been established as an effective component of resident education in other specialties, including dermatopathology and surgical specialties, and other healthcare domains.As we develop new programs for residents, consideration should be given to other models such as interactive case-based methods or an inverted classroom. In the latter, individual self-directed learning occurs prior to the classroom instruction in the form of pre-recorded videos, facilitating increased time for application during subsequent case-based discussions or simulations. A recent study demonstrated that a video-based, inverted classroom surgical curriculum is effective in teaching surgical skills to dermatology residents. On the flip side, the use of an interactive, computerized case simulation system increased learner satisfaction but did not result in any differences on testing of the content.Learner enjoyment with different models must also be considered. For example, while the inverted classroom model has been shown to increase learner autonomy and retention of material, it may also decrease the enjoyment of the learning process compared to the traditional model.Assessment and validation of virtual learning tools is critical. A post-initiative evaluation of educational programs created during the pandemic has provided some insight on effectiveness. However, this type of evaluation is limited: it provides a retrospective and reactionary perspective. Going forward, pre-determined teaching objectives and critical evaluations of virtual educational initiatives should be employed. Primary and secondary outcomes, such as knowledge and skill acquisition and retention, learner satisfaction, and cost of creation and implementation, will have to be identified and assessed.The current situation may be an opportunity to standardize undergraduate dermatologic education across the country. For example, undergraduate dermatology education coordinators could collaborate to develop a national repository of online lectures for medical students. A case-based or inverted classroom model could then be implemented whereby medical students review these lectures prior to sessions organized by their individual institution.The potential for research projects spurred by COVID-19 in basic science, clinical dermatology, medical education, and wellness realms is broad . We stroOverall, strong momentum for national virtual education has been initiated for postgraduate learners. With the transition of dermatology to CBD, the authors strongly believe that some distance and virtual education initiatives will become enduring components of resident education. This will necessitate ongoing collaborative efforts for synchronization, sustainability and evaluation. Some initiatives may lose their relevance as we transition back to a “new normal” with less stringent public health guidelines.The COVID-19 pandemic has created indefinite gaps in medical student and resident dermatologic education. Nevertheless, this sudden global crisis has accelerated innovation in medical education. As we continue to comply with physical distancing, ongoing implementation of novel techniques, collaboration, and evaluation will be required to maintain rigorous dermatologic education for residents and medical students. These unprecedented and novel changes will likely impact the training of future dermatologists and their physician colleagues.


The recent revelation that the gut microbiome, home to approximately 100 trillion microorganisms, is implicated in the development of both health and disease has spurred an exponential increase in interdisciplinary research involving gut microbiology. In all this hype, there is a need to better understand and contextualize the emerging evidence for the role of the gut microbiota in neurodegenerative and neurodevelopmental diseases, including central nervous system (CNS) malignancies. In this review, we aim to unravel the complex interactions of the microbiota-gut-brain-axis to pave a better understanding of microbiota-mediated pathogenesis, avenues for noninvasive prognosis, and therapeutic possibilities leveraging microbiota-gut-brain-axis modulations. We further provide insights of the ongoing transition from bench to bedside and discuss limitations of current approaches. Ultimately, we urge the continued development of synergistic therapeutic models with considerable consideration of the many gut-resident bacteria that will enable significant progress for the treatment of many neurological diseases. The gut microbiome comprises a vast ecology of commensal bacteria, archaea, fungi, and viruses in and on the body.The signaling mechanism behind the microbiota-gut-brain axis communication is of particular interest when considering therapeutic design. The brain modulates gut function through the hypothalamic-pituitary-adrenal axis and the autonomic nervous system; norepinephrine, for example, is released by the brain during stress and has been found to stimulate gut pathogen proliferation.,Notably, of the many pathways possible, the vagus nerve is the most direct route as different receptors on the vagal afferents detect then transmit stimuli from the gut to the brain. In fact, the vagus nerve was recently implicated in CNS mood and behavior via influencing CNS reward neurons.Microbial-derived metabolites and products are major contributors in the MGBA that exert their effects primarily through receptor-mediated interactions on various host tissues or cells. One of the most well-characterized metabolites are short-chain fatty acids (SCFAs) and endogenous tryptophan. SCFAs, a derivative of microbial-induced decomposition of carbohydrates, have been suggested to contribute to glucose homeostasis, mucosal serotonin release, lymphocyte function, and influence learning and memory acquisition via preservation of brain integrity.14C-SCFAs into the carotid artery.Microbial-induced metabolism of dietary tryptophan to indole compounds also bears mention as some bacteria, particularly certain species of the Lactobacillus genus, were recently identified to play key roles in activating the aryl hydrocarbon receptor and, consequently, in cell cycle regulation and T-cell differentiation.Microbial-derived products also play major roles in the MGBA communication, often through interactions with the toll-like receptors in the ENS and CNS that can sense the products through recognized molecular patterns. Lipopolysaccharide (LPS), a component released by gram-negative bacteria, for example, has been shown to be recognized by toll-like receptors 4, which are primarily expressed on microglia of the CNS, that subsequently induces proinflammatory cytokine production and proliferation.B. fragilis and is recognized by toll-like receptors 2 that then induce a protective CNS anti-inflammation response.Overall, the interactions of microbial-derived metabolites and products within the MGBA is abundantly diverse and complex where one metabolite may interact with multiple receptors spanning multiple tissue and cell types, resulting in an array of different physiological, immune, and CNS responses. Looking forward, therapeutic intervention with SCFAs may be a particularly promising candidate and studies, though still somewhat inconsistent, are already underway in models of autism spectrum disorder,Gut hormones are also important to consider in gut-brain signaling. Casual links have been observed between obesity and mood disorders, further reinforced by correlations of several gut hormones  with anxiety and depression.,,Neuroactive molecules represent another class of microbiota-affiliated molecules that also influence the MGBA through likely the ENS. Gut microbes have been recognized to modulate, if not directly synthesize, neuroactive substances such as dopamine, noradrenaline, acetylcholine, histamine, melatonin, and gamma-aminobutyric acid that, in turn, modulate the CNS.Direct microbial invasion beyond the BBB is also possible, although the specific mechanisms and exact point of entry remains poorly understood. In general, while the duration and minimum level of bacteria required to cause bacterial invasion varies among the different pathogens, a common prerequisite for bacterial pathogenesis is often the asymptomatic colonization of respiratory, pharyngeal, or digestive mucosal surfaces followed by a sustained survival in the bloodstream – resisting or escaping phagocytosis and other immune responses – before interacting with brain endothelial cells and finally breaching the BBB through various pathways.–in vitro data to in vivo adhesive characteristics of pathogens is still questionable since bacteria must withstand blood flow in vivo. Nonetheless, bypassing the BBB remains a prevalent clinical challenge for delivering drugs to treat neurological diseases, so understanding how some bacteria succeed via direct interactions with the CNS barriers is both clinically relevant and important when designing therapies.,There has been increasing evidence implicating the imbalance of the microflora in the development of various neurodevelopmental and neurodegenerative diseases. As several reviews have already comprehensively addressed this, the associations are only briefly discussed.Prevotellaceae, which was found to sharply decline following PD onset, and Enterobacteriaceae, whose increased abundance was found to positively correlate with PD symptom severity.Prevotellaceae abundance and constipation status boasted a specificity of 90.3%.Parkinson's disease (PD) is a well-studied example where the initiation of PD etiology is suspected to begin in the gut, with emerging evidence of α-synucleinopathy originating in the ENS during early stages of PD progression.,H. pylori, for example, has been reported to induce hyperphosphorylation of tau protein as well as secretion of inflammatory mediators and amyloidsH. pylori infection via triple eradication therapy was observed to cause improved cognitive parameters in AD patients.Alzheimer's disease (AD) etiology has also been strongly linked to the microbiota; metabolic molecules from microbiota have been associated with phosphorylated tau/Aβ42 AD biomarkers, amyloid-β load, and activation of the NLRP3 inflammasome pathway.Akkermansia muciniphila and Acinetobacter calcoaceticus that were later observed in vitro to contribute to increased proinflammatory T-cell response and weakened Tregs activity.Fusobacteria with future MS relapse possibilities.Multiple sclerosis (MS) and autism spectrum disorder (ASD), though not as extensively elucidated with regards to associations with the gut microbiome, also bear mention. A clinical trial investigation of gut microbial profile in MS patients, for example, has revealed elevated levels of specific microbial taxa including Meanwhile, studies have also noted considerable microbial composition differences between individuals with ASD and neurotypical individuals, including a decreased abundance of Bifidobacterium, considered a beneficial genus, and an increased abundance of Clostridia, a potentially pathogenic genus.Firmicutes to Bacteroides, and relative abundance of Verrcomicrobia and Akkermansia.Lastly, brain tumors are also speculated to be impacted in their initiation or progression by the microbiome via an altered immune system, microbial-induced genotoxic effects, or signaling/proliferation pathways changes.More broadly, while the implication of the microbiota in CNS diseases is of significant interest for reshaping therapeutic design, gut-modulated physiological and cellular changes are likely extremely complex and multifaceted. Future studies will need to investigate the translatability of correlative observations and verify the reproducibility of existing experimental findings. It is also important to consider that pre-clinical and clinical experiments for CNS diseases often involve confounding variables such as antibiotics and medication that, when coupled with other factors like differences in geographical location and diet, will significantly impact gut composition beyond the therapy or model of study. More causative studies must be performed for the role of the gut microbiota in neurodegenerative or neurodevelopmental disease and vice versa: how CNS diseases themselves in-turn may influence the composition of the gut microbiota. In addition, there exists an exciting possibility to leverage growing knowledge of gut bacteria to serve as predictive biomarkers of disease; however more diverse cohorts of patients must be explored to validate the translatability of microbial biomarkers across different ethnic and geographical groups.Already, intervention strategies targeting the gut microbiota and their subsequent translation into clinical trials are underway .Table 1GFecal Microbiota Transplantation (FMT) was shown to prevent disease progression of MSAntibiotics play an important role in changing the composition of gut bacteria and thus, influencing immune response and therapeutic efficacy. In gliomas, for example, antibiotics are essential for preventing or treating life-threatening infections in patients resulting from microbial-induced immunosuppression and other detrimental effects caused by harmful bacteria; more broadly, targeting the gut microbiome using appropriate antibiotics may allow for improved tumor control. Antibiotics may even be used as a direct therapy, with the antibiotic clofoctol recently being demonstrated to reduce glioma growth via inhibition of glioma-stem-cell proliferation through upregulating Krüppel-like factor 13, a tumor suppressor gene.Enterococcus faecium, which increased risk of bloodstream infections and patient mortality.Prevotellaceae, Rikenellacaea, and Helicobacteraceae families.Probiotics are often components of food products or supplements that we consume daily, such as yogurt. Increasingly, more “designer probiotics” have been introduced that are genetically engineered to maximize the beneficial effects of select bacteria and are often included in more traditional pharmaceutical routes.Bifidobacteria and Lactobacillus – which promotes GABA levels and expression of neurotropic factors – including reduced occurrences of seizure episodes in patients with drug-resistant epilepsy,in vitro PD model (SH-SY5Y) was able to increase cell viability via reducing oxidative stress and neuronal death as well as reverse phenotypic deficits in motor behavior when placed in a rodent PD-model.Lactobacillus Plantarum in several CNS diseases, including major depressive disorder (Identifier: NCT03237078), ADHD (Identifier: NCT04167995), ASD (Identifier: NCT03982290), and stress (Identifier: NCT03370458). Overall, the results to date convey great potential in harnessing beneficial gut bacteria as novel therapeutic options for neurological diseases. However, there is wide variability in composition, stability, and authenticity of probiotics with no consensus on dosage, duration, and specific strains to use; moreover, host colonization resistance brings a notable concern with any use of probiotic-based therapies. Thus, caution must be exercised in any use of probiotics to patients until more holistic characterization of these bacteria are conducted. Admittedly, while beneficial effects are not durable as probiotics generally cannot colonize in the acidic environment of the gut for a long time,Diet, though not necessarily a therapeutic treatment, also plays a significant role, especially as accumulating evidence indicate that intensive changes to dietary regimens can rapidly alter gut microbial profiles. In fact, a specific dietary class has been recognized as prebiotics, which are indigestible fibers  selectively utilized by gut microorganisms as the primary nutrition source for conferral of health benefits. Commonly found in fruits, vegetables, grains, and human milk, prebiotics have the advantage of modulating the gut microbiota more globally. Reductions in dietary fiber, for example, significantly decreases the abundance of immune-promoting Faecalibacterium prausnitzii and SCFA butyrate, which help support digestive health. Conversely, a high-fat, low-fiber animal-based diet decreased levels of beneficial metabolic bacteria and increased bile-tolerant microorganisms.synbiotics, which are a combination of probiotics and prebiotics in which prebiotics are used to supplement (providing a source of fermentable fiber) and enhance the viability of the probiotic,postbiotics, which entail metabolites of bacterial fermentation including functional bioactive compounds such as SCFAs and gut peptides. While there is still a need for more elucidated targets, the fact that postbiotics are nonviable entities provides a distinct advantage over probiotics in terms of increased shelf life and safety profile.The ability to unravel the interactions between the microbiome and therapeutic response will likely catalyze the next big change in the discovery pipelines of therapeutic developments; it is not a stretch to say that it may soon be routine for human-directed drugs to be screened for impacts on microbial populations.The evolution of the microbiome field has enabled a significant step closer to understanding CNS disease treatments through untangling the intricate networks of the immune system, gut microbiota, and microbiota-gut-brain axis. Moving forward, it will be important to recognize that the microbiome may be a key contributor to the prevention, development, treatment, and management of CNS diseases, where something as simple as an every-day diet may pose significant therapeutic potential especially when synergized with existing therapies. Moreover, with increased knowledge on the gut microbiota, new strategies will become available for non-invasive predictors of prognosis and predictive biomarkers  for a variety of CNS disorders and respective outcomes. Ultimately, the pliability of the microbiota promises exciting potential and hope for ushering in a new frontier for precision medicine.Lactobacillus and Bifidobacterium spp.) display reproducible and robust benign physiological effects and even fewer still are actively involved in clinical trials (of which results largely remain inconclusive). With the increasing presence of many commercially available over-the-counter antibiotics and dietary regimens boasting of probiotics, a call must be made for greater public awareness in how they may ultimately impact our gut microbiome and, consequently, our health.There remain key reservations and unknowns about the MGBA founded upon the interwoven complexities that make up human neurological diseases. For one, gut microbial profile varies widely between individuals and even if two individuals harbor the same bacterial species, they could vary in strain that possess different functionalities within the host. Additionally, within the individual, there is a duplicity in microbial roles to physiological health such that the same microbe could both harm and benefit human health. Secondly, as existing animal models are limited in their ability to replicate the totality of any human disease, the reproducibility of results observed preclinically in mostly rodent models remains largely unanswered, posing obstacles to the successful translation to the bench side. Moreover, with the variety of potential mechanisms for targeting the gut-brain-axis, there remains a crucial need to separate correlation from causality and caution must be employed to ensure no off-side effects. Of the limited existing preclinical data, very few microorganisms (e.g., K.S. owns equity in and is a member of the Board of Directors of AMASA Therapeutics, a company developing stem cell–based therapies for cancer. K.S.’s interests were reviewed and are managed by Brigham and Women's Hospital and Partners HealthCare in accordance with conflict-of-interest policies.


While two-dimensional models have been invaluable, they are not suitable for studying patient-specific tumor biology and drug response. Recent developments in three-dimensional (3D) models have led to the prominence of organized structures grown in a 3D environment called “organoids.” Breast organoids can accurately recapitulate the in vivo breast microenvironment and have been used to examine factors that affect signaling transduction, gene expression, and tissue remodeling. In this review, the applications, components, and protocols for development of breast organoids are discussed. We summarize studies that describe the utility of breast organoids, including in the study of normal mammary gland development and tumorigenesis. Finally, we provide an overview of protocols for development of breast organoids, and the advantages and disadvantages of different techniques in studies are described. The included studies have shown that breast organoids will continue to serve as a crucial platform for understanding of progression of BC tumors and the testing of novel therapeutics.Breast cancer (BC) is the most frequently diagnosed malignancy among women globally. Although mouse models have been critical in advancing the knowledge of BC tumorigenesis and progression, human breast models comprising the breast tissue microenvironment are needed to help elucidate the underlying mechanisms of BC risk factors. As such, it is essential to identify an  As a rein vivo  cell cultures and cell line-derived xenograft models were commonly used to study breast cancer. While these models have been invaluable, they are not suitable for studying patient-specific tumor biology and drug response. Due to the limitation of cell-cell and cell-extracellular matrix (ECM) interactions, cell cultures grown in 2D cultures experience altered cell signaling pathways and therefore are not representative of the corresponding tissue in vivo . Cells gin vivo . Currentin vivo . To addrin vivo systems. Organoid systems are used to recapitulate several diseases, including neurodevelopmental disorders, liver conditions, colorectal cancer, prostate cancer, gastric cancer, esophageal cancer, and breast cancer  that can be incorporated to study drug treatment by filling mammary epithelial cell-lined lumens with DCIS cells to create a DCIS-like structure (Importantly, breast organoids can be used as models for disease . They catructure . Recentltructure .in vitro (Organoids are incorporated into matrices that contain basement membrane proteins essential for epithelial cell function and polarization. Placement into these matrices enables cells to organize into 3D structures in vitro . Matricein vitro . Criticain vitro . Matrix in vitro .Current matrices include both natural and synthetic scaffolds. Matrigel and collagen I are two common natural scaffolds. Commercially available Matrigel, which is Engelbreth-Holm-Swarm ECM extract, is the most frequently used matrix gel, and it is rich in ECM proteins like laminin, collagen IV, entactin/nidogen, heparan sulfate proteoglycans, and growth factors.in vivo (Interestingly, Nguyen-Ngoc et al. utilized different ECM gels to test the importance of the ECM in tumor cell dissemination and discovered that in Matrigel, malignant epithelium grew without protrusions whereas in collagen I, epithelium from the same tumor promoted an invasive phenotype . As suchin vivo . The conin vivo tissue as that of naturally derived scaffolds (Much less commonly utilized in breast organoid culture, synthetic scaffolds include polymers that retain the mechanical properties of the tumors, such as polyethylene glycol, polyvinyl alcohol, polycaprolactone, and polylactide-co-glycolide, although their stiffness may not be as similar to caffolds .in vitro, and other regulators of signaling pathways are added to generate growth and differentiation of organoids (Many breast organoid protocols have been developed with the main variations consisting of differences in matrix type, medium components, and plating techniques . The firrganoids . Unique rganoids .in vivo environments in which the inner portion of tumors are not as vascularized and receive less nutrients. Multi-layering methods also enable co-culturing of various cell types (In addition to utilizing different types of matrices and media components, there are several layering methods that can be used in the development of breast organoids. The single layer technique entails cells being mixed directly with the matrix and polymerized in one thick layer. In their protocol, Lee et al. describe a 3D embedded assay in which they coat a culture surface with a thin layer of ECM extract before plating breast cancer cells resuspended in ECM extract . The advll types . Aside fll types . This tell types . For exall types . Dekkersll types . With thThe ECM scaffold provides a structure to guide cell organization. Scaffolds such as Matrigel remain the most prominent matrix, but some scientists utilize decellularization strategies to remove native cells and genetic material from a naturally derived ECM and personalize it with the patient’s own cells. Gilpin and Yang described the advantages and disadvantages of chemical and enzymatic, physical, or combination methods for decellularization . ChemicaRecent studies have also suggested methods to improve the reproducibility of organoid development by utilizing 3D bioprinting. Reid et al. explained the benefits of 3D bioprinting in a study that utilized immortalized non-tumorigenic human breast epithelial cell lines and a collagen I matrix. Results included the ability to form organoids from very few cells, increased efficiency, and greater control over the location of cells within the gel . Mollicain vivo tissue architecture and cell-cell/matrix interactions.It is evident that breast organoid technology is revolutionizing the study of normal human breast development as well as tumorigenesis. However, there are still limited breast organoid models that have been able to recapitulate native breast tissue ECM composition or fiber structure. It is important to note that many current protocols involve several steps of differential centrifugation and cell straining in order to separate and purify mammary epithelial cells from surrounding stromal cells before growth in 3D culture. Using purified epithelial cells and stromal cells to produce breast organoids may not recapitulate the in vivo breast architecture. Rosenbluth et al. successfully included stromal cells in their breast organoid model but showed that after several passages, stromal cells were lost. The differences in epithelial structure and cell populations between the resulting organoids and matched human breast tissue was in part attributed to the absence of stromal cells in passaged organoids, which demonstrates the significance of stromal cells in these models (Further research should be performed to incorporate multiple cell types in breast organoid models. Although epithelium is only required in the current accepted definition of organoids, incorporation of other cell types may contribute to a more accurate recapitulation of e models . Davaadee models . Other se models . Moreovee models . ContinuThis review paper summarizes the multiple applications of breast organoids and provides an overview of the protocols that are used to generate these organoids. Breast organoids have significant utility in understanding not only normal human mammary gland development, but also breast tumor development. Future directions will include addressing updates on breast organoid technology as well as continuing to incorporate multiple cell types into organoid models. Breast organoids will continue to serve as a crucial platform for understanding of the progression of BC tumors and the testing of novel therapeutics.


We present histopathological criteria for diagnosing keratoacanthoma (KA). In KA, four histological stages are recognized, which are the early/proliferative stage, well-developed stage, regressing stage and regressed stage. In diagnosing KA, we emphasize that KA consists of the proliferation of enlarged pale pink cells with ground glass-like cytoplasm without nuclear atypia, other than crateriform architecture. KA sometimes exhibits malignant transformation within the lesions. We describe the characteristics of benign and malignant epithelial crateriform tumors that should be differentiated from KA. We also present the data of histopathological diagnosis of lesions clinically diagnosed as KA, its natural course and related lesions after partial biopsy, and incidence of crateriform epithelial neoplasms. Based on these data, we recommend complete excision of the lesion when KA is clinically suspected, especially when the lesion is located on a sun-exposed area of an elderly patient. If complete excision is impossible, partial excision of a sufficient specimen with intact architecture is required. In such a case, however, careful investigation after biopsy will be needed, even if the histopathological diagnosis is KA, because there is some possibility that a conventional SCC lesion remains in the residual tissue. Keratoacanthoma (KA) often occurs in a solitary form and exhibits a distinct clinical and histopathological presentation . WhetherIn this article, we want to present the true characteristics of solitary KA based on its distinctive histopathological criteria, in addition to histopathological findings of other epithelial crateriform tumors that should be differentiated from KA. Our classification of epithelial crateriform tumors is stated in Solitary KA usually develops on sun-exposed areas of elderly patients. Its clinical findings are characterized by a flesh to pink colored crater-like nodule with a central keratotic plug. An essential clinical characteristic of solitary KA is its self-limiting course, with rapid enlargement within several weeks and spontaneous regression within several months. Such a clinical course is highly important in diagnosing KA.Solitary KA has different histopathological features depending on the stage of the lesion at the time of biopsy or resection ,12,13. FKA histopathologically exhibits characteristic findings through all stages except in the regressed stage. These include an exo-endophytic architecture, a relatively well-defined, almost symmetrical outline and a multilobular lesion with a central keratinous plug. It also presents overhanging epithelial lips covered with normal epidermis. Furthermore, other findings should be emphasized: (i) presence of invaginated infundibular structures (laminated keratinization) and lobules with enlarged pale pink cells with ground glass-like cytoplasm, which generally lack nuclear atypia; (ii) lobules of large pale eosinophilic cells with a few layers of basophilic cells at their periphery; (iii) possible nuclear atypia or mitotic figures, limited to the peripheral areas of the basophilic cells; and (iv) minimally infiltrating borders. In particular, proliferation of enlarged pale pink cells with ground glass-like cytoplasm without nuclear atypia is the most important finding in diagnosing KA and differentiating KA from SCC. In KA, the crateriform architecture is characteristic and can be recognized in most cases, but that is not essential. We previously reported cases having the same components as conventional KA without the crateriform architecture as keratoacanthoma en plaque/nodule  Figure .The early/ proliferative stage of KA is histopathologically characterized by several keratin-filled invaginations of the epidermis or infundibulum, demonstrating a laminated pattern of keratinization, often with prominent keratohyalin granules. In the deeper areas, pale pink keratinocytes with a glassy appearance are observed. The deeper areas of the lesion are sometimes poorly demarcated from the surrounding stroma and exhibit slightly invasive growth .The well-developed stage of KA exhibits the following histopathological findings: (i) characteristic symmetric, crateriform, exo-endophytic architecture; (ii) contiguous, dilated infundibular structures (multilocular and multilobular) with a central large keratotic horn situated above isthmic differentiation; (iii) overhanging epithelial lips with a normal overlying epidermis; and (iv) characteristic neoplastic lobules with isthmic differentiation  in most parts . There aThe regressing stage of KA maintains a crateriform architecture, but it becomes one or two keratin-filled and shallow crateriform structures . The regThe regressed stage of KA is a depressed epidermal lesion with overhanging or rising edges, and the epidermis is flattened and atrophic with loss of rete ridges .KA-like SCC  and KA wWe previously reported crateriform epithelial tumors exhibiting some histopathological overlap with KA that failed to meet all of the histological criteria for a diagnosis of KA and had some verrucous features, and we proposed the term crateriform verruca (CFV) to differentiate these verrucous neoplasms from KA . CFV oftHistopathologically, CFV is characterized by finger-like exophytic projections associated with hyperkeratosis (parakeratosis or orthokeratosis), focal hypergranulosis  and acanthosis, together with epithelial lip-like structures at the periphery . CharactCSK is an exo-endophytic lesion, often having finger-like exophytic projections, which features hyperkeratosis and acanthosis with the proliferation of basaloid cells. Pseudohorn cysts are often evident .Crateriform Bowen’s disease is an exo-endophytic lesion with a central keratotic horn ,20. It iThis type of SCC is an exo-endophytic lesion exhibiting the full thickness of atypical keratinocytes with bowenoid features in the epidermis and into the dermis ,15 Figu. EpithelThe term follicular SCC was first proposed for folliculocentric SCC , and KosAnsai, the co-author, reported the histopathological diagnosis of 1527 patients who were clinically diagnosed with KA at a Japanese institution . Those lTakai and colleagues reported the clinical courses in 66 cases of KA and related lesions after partial biopsy . They hiWe previously reported the incidence of 380 epidermal crateriform tumors using our classification . There wComplete surgical excision of the lesion is the most effective therapy for solitary KA. Therefore, we recommend complete excision of the lesion when KA is clinically suspected, especially when the lesion is located on a sun-exposed area in an elderly patient. If complete excision is impossible, partial excision of a sufficient specimen with intact architecture is required. In such a case, however, careful investigation after biopsy will be needed, even if the histopathological diagnosis is KA, because there is some possibility that a conventional SCC lesion remains in the residual tissue .As mentioned above, solitary KA is a benign epithelial neoplasm with follicular differentiation that sometimes grows conventional SCC within it and is different from conventional SCC. We consider these to be the true characteristics of solitary KA.


Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide, afflicting millions of patients  and local conduction velocities as defined by bipolar activation mapping in sinus rhythm. They found that LGE MRI signal intensity correlated with colocalized conduction velocity, but only at spatial scaling of a mapping catheter electrode. This finding extends work by Caixal et al.  was investigated by l et al.  who receOh et al. used transcriptomic bioinformatic analysis of atria to investigate novel collagen pathways that increase AF vulnerability. During 6 weeks of exercise, there was differential regulation of atrial genes linked to mechanosensing, extracellular matrix and tumor necrosis factor pathways, which was 2-fold higher than in the ventricles. Transcriptomics were temporally dynamic and related to increased preload and atrial stretch seen with exercise. Tang et al. also studied molecular modulation of structural remodelling, in particular the regulation of angiotensin 2-induced atrial fibrosis. In rats treated for 2-weeks with apelin, an inhibitor of fibrosis, there was a decrease in angiotensin 2-induced atrial fibrosis and AF inducibility with programmed stimulation. The protective effects of apelin were mediated by suppression of Smad2-dependent fibrosis, which may provide an effective up-stream therapy for atrial fibrosis and AF.The mechanisms of conditional AF structural modelling were further explored in two mechanistic studies. In a mouse model of exercise-induced AF, Rodrigo et al. evaluated regional differences in activation rates during AF using non-invasive electrocardiographic imaging (ECGI) and contact mapping. ECGI provided a moderate estimation of intracardiac recording-based activation rates in AF after filtering by high spectral organization. The ECGI-derived highest dominant frequency predicted acute AF ablation success suggesting that this approach may provide an effective tool to identify patient responders for personalized ablation therapy. The importance of discerning repetitive AF propagation as putative targets for catheter ablation was also studied by Zeemering et al. These AF patterns were automatically identified from high-density-electrode array recordings in goat model of AF using a novel computational tool based on recurrence plots. Activation breakthrough and reentry were seen as repetitive conduction patterns which became shorter with more prolonged AF duration. Using this methodology with high-resolution clinical mapping catheters may delineate putative targets for AF catheter ablation.With respect to characterizing electrical modelling, Ho et al. and Ng et al. provide a comprehensive review of electrophenotyping to improve our understanding of patient-specific AF mechanisms than may guide personalized therapy. This is necessary because AF mechanisms and propagation is dependent on the extent of structural and electrical remodelling, which can vary even among patients with comparable AF risk factors, AF duration, and cardiovascular disease.The final two contributions by In summary, improved therapy for AF is likely to require better delineation of FAM in individual patients, both in its structural and electrical components. Structural FAM is now widely appreciated, yet it is undefined whether to identify this by non-invasive imaging, by voltage mapping or via its functional effects such as conduction slowing. It is equally undefined how to treat structural FAM. Electrically, it is critical to delineate how FAM leads to functional arrhythmias. Identification of patient-specific AF triggers or AF sustaining substrates, such as localized drivers, is limited by the spatial resolution of clinical tools and lack of accepted gold standards for validation. Electrophenotyping of patients with AF may enable us to identify those in whom therapy should target FAM, and those in whom FAM and AF may progress and who may instead benefit from more general strategies. The 10 articles in this Research Topic add to our understanding of FAM, and provide exciting areas for further investigation. We congratulate the authors.All authors contributed to content and critical review of this editorial.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Acute myeloid leukemia (AML) is a complex hematological malignancy characterized by extensive heterogeneity in genetics, response to therapy and long-term outcomes, making it a prototype example of development for personalized medicine. Given the accessibility to hematologic malignancy patient samples and recent advances in high-throughput technologies, large amounts of biological data that are clinically relevant for diagnosis, risk stratification and targeted drug development have been generated. Recent studies highlight the potential of implementing genomic-based and phenotypic-based screens in clinics to improve survival in patients with refractory AML. In this review, we will discuss successful applications as well as challenges of most up-to-date high-throughput technologies, including artificial intelligence (AI) approaches, in the development of personalized medicine for AML, and recent clinical studies for evaluating the utility of integrating genomics-guided and drug sensitivity testing-guided treatment approaches for AML patients.  Acute myeloid leukemia (AML) is the most common myeloid neoplasm. The condition is characterized by abnormal clonal expansion and aberrant differentiation of immature clonal myeloid cells . IncreasExtensive efforts over the past decades have expanded our knowledge in the functional genomic landscape and molecular events that lead to initiation, progression and resistance of AML. This further adds guidance for treatment decisions to match prognostic factors and treatment responses, that result in better risk stratification and survival outcomes for patients. A small number of targeted therapies aimed at specific mutations and essential molecules involved in leukemogenic pathways has been developed and approved for AML patients with the aim of improving clinical outcomes. These include FLT3 inhibitors , CD33 monoclonal antibody , IDH2 inhibitors , IDH1 inhibitors , BCL2 inhibitors  and hedgehog signalling inhibitors  . AlthougThere is a shift in therapeutic strategies from conventional combination chemotherapy regimens to a more personalised treatment approach based on individual patient-specific characteristics, i.e., precision medicine. Besides the epidemiological and clinical information, precision medicine largely relies on genetic information provided by high throughput sequencing technologies. A plethora of pre-clinical and clinical studies are currently evaluating the outcomes of genomics-guided, phenomics-guided and genomics-phenomics-guided treatment approaches. This significantly benefits relapsed leukemia patients and those unable to tolerate aggressive chemotherapy .Emerging approaches in precision medicine using high-throughput technologies, such as sequencing analysis and drug screening, play essential roles in generating datasets that are valuable for stratifying patients for treatment and guiding drug discovery. In addition, artificial intelligence (AI) has recently garnered attention in cancer therapy due to its ability in enhancing drug discovery, development and administration . In thisThe applications of genomics, epigenomics, transcriptomics, proteomics and metabolomics are attributed to recent advances in next generation genome sequencing, bioinformatics, proteomic analytic tools, along with high-throughput technologies. This is a powerful tool that provides deep and robust data, and has led to a rapid discovery of biomarker candidates in the field of oncology. Furthermore, extended research from these discoveries have provided potential therapeutic targets. This in turn will set a systematic approach to devise strategies to guide therapies, address disease risks, and predict clinical outcomes. The main challenges to bring these assays from bench to bedside are mainly due to high costs, long turnaround times and difficulty in data interpretation.Next generation sequencing (NGS) yielding billions of reads in a single run has allowed unparalleled efficiencies, unlike conventional Sanger sequencing. Using this technology, this has allowed faster interrogation of whole genomes, and extended towards transcriptome sequencing to understand protein profiles and interactions. With the efforts of multiple cancer centres and sequencing laboratories, related patient centric databases have been set up in the public domain. This included the Cancer Genome Atlas Research Network among many others. The database has transformed the understanding of leukemia and uncovered multiple genetic alterations and epigenetic modifications. Deep analysis and prediction models have elucidated information pertaining to the disease molecular subtypes, aid therapy selection, identify targets for improve drug delivery and novel molecular targets in drug discovery.There is strong evidence that genomic alterations could be identified as molecular targets. One successful example is the identification of all-trans retinoic acid (ATRA) and arsenic trioxide therapy for acute promyelocytic leukemia (APL). The majority (~95%) of APL is characterized by a t  translocation resulting in the fusion gene transcript promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR-α). The discovery of this translocation has clinical significance due to its responsiveness to arsenic trioxide and ATRA which promote degradation of PML-RAR-α . ATRA anAnother successful example is the identification of mutations of FMS-like tyrosine kinase 3 (FLT3) receptor in AML . FLT3 muA significant finding from genomic sequencing in AML is the discovery of mutations frequently localized to genes with epigenetic functions. These include DNMT3A, TET2, IDH1, IDH2, CBP, KAT6A, HDAC2, HDAC3, EZH2, NSD1, ASXL1 and ASXL2 . EpigeneAlthough epigenetic drugs display great therapeutic potential by targeting multiple pathways simultaneously, its indication for use is still limited and in its infancy. Larger scale randomized control trials and long-term studies are needed to address the prognostication and predictive capabilities and address any potential adverse events when used in combination with chemotherapy. Various clinical trials are currently ongoing to evaluate genomics-guided treatment approaches in either relapsed or refractory AML. However, the genomic technologies fail to evaluate changes in signalling pathways or proteins that could more directly facilitate risk stratification, predict chemoresistance and aid selection of therapy, independent of mutational status.The two most frequently used high-throughput proteomics technologies in leukemia research are mass spectrometry (MS) and antibody-based reverse phase protein array (RPPA), which allow distinguishing protein isoforms, post-translational modifications, and amino acid changes. MS is often used as a de novo discovery platform as it is unbiased towards the protein targets of interest whereas RPPA uses validated monoclonal antibodies to measure protein expression. RPPA is more suitable than MS for direct clinical applications with actual primary samples as it uses less amount of samples. Proteomics technologies used in leukemia studies are helpful to identify protein markers that stratify patients on their prognosis or response to treatment, through comparing protein profiles between leukemia patients and healthy volunteers, between pre and post treatment samples, between drug-resistant and -sensitive cell lines, between leukemia stem/progenitors and bulk cells ,27,28,29Strategies that analyze and integrate net effects of multiple signalling transduction pathways on the entire spectrum of protein effectors and actuators will provide a more complete view of the functions of the leukemic cell population. Large-scale proteomics enable the system-wide characterization of signalling events in the context of functionally related protein groups. This is important as targeting essential signalling pathways has been proven to be effective in improving AML patients’ clinical outcome. BCL-2 is an anti-apoptotic enzyme and prevents leukemia cell death triggered by intrinsic apoptotic mitochondrial pathway . VenetocThe application of proteomics technologies in leukemia has been limited to identification of diagnostic and prognostic biomarkers rather than therapeutic targets in the research laboratories. The critical need is to translate these biomarker discoveries to routine clinical use at an affordable cost. Classification of protein signatures in patients may provide potential drug targets. The challenges to the routine clinical use of proteomics technologies are to develop protein assessment kits that could rapidly enable classification of the protein signature. The ability of utilizing these signatures to evolve as new drugs is also needed ,35.1H NMR) and MS are used as the primary platforms to enable the identification of metabolites and other small molecules in biological samples. Substantial evidence has revealed the unique feature of leukemia cells in the context of cell energy, nucleic acid precursors, amino acids and lipids [Similar to genomics and proteomics, metabolic profiling revealed by metabolomics analysis are useful in diagnosis, risk stratification and targeted therapy in AML. The strategy for targeting metabolic activities in AML patients has been employed since cytarabine was used as a standard therapy. Its mechanism of action interferes with nucleotide metabolism . Analytid lipids ,38,39,40d lipids ,25. ThisPreclinical and clinical studies highlight the therapeutic potential of several metabolic targets in AML, such as fructose, nucleotide biosynthesis and oxidative phosphorylation . HoweverAlthough the recurrent genetic/epigenetic/proteomic alterations in acute leukaemia have been linked to actionable targets, identification of these targets in patients using these newer technologies does not always lead to effective therapies. A strategy to circumvent this issue is to use an unbiased drug screening approach, such as high-throughput screening (HTS). HTS plays a pivotal role in the early stages of cancer drug-discovery. The size, quality and content of the compound library are important factors in determining successful HTS screens. Clinically available drug libraries are often used for HTS. Disease models are developed for HTS, including immortalized cell lines, engineered cell systems (eg. reporter cell lines and isogenic cell lines) and co-culture conditions  and patient-derived cells (PDCs).Substantial evidence has shown that DST-guided therapy demonstrates clinical benefits in cancer patients. Chia et al. demonstrated that using monotherapy of gefitinib resulted in significant cancer regression within 6 weeks of treatment in a patient with recurrent oral squamous cell carcinoma . This taDST on consecutive liquid biopsy samples from the patients allows the physician to rapidly adapt treatment plans in response to drug resistance. Pemovska et al. reported that DST was predictive of clinical response, and therapy based on DST resulted in clinical responses that met the European LeukemiaNet criteria. These included morphological leukemia free state and complete remission . By perfTanacetum parthenium, and shikonin, a naphthoquinone found in the root of Lithospermum erythrorhizon, in pediatric precursor-B cell acute lymphoblastic leukemia [Using DST-based HTS platform, a number of recent studies identified combinatory anti-cancer therapies. Drenberg et al. found that gemcitabine and cabazitaxel may be useful for treating pediatric AML . Focusinleukemia . Kurtz eleukemia .Apart from using microplate readers for readout in DST assay mentioned above, high-throughput flow cytometry has also been used in DST assay. Using 54 patient samples in a large panel of approved and investigational drugs, Spinner et al. demonstrated the utility of a fully automated ex vivo DST platform using high-throughput flow cytometry to identify potential therapeutic drugs for patients with refractory myeloid neoplasms . Drug trTo harness the power of high throughput screening, the choice of data analysis methods and subsequent computational approaches are crucial. Initial analysis with the use of readout can range from as simple as relative drug inhibition scores or half maximal effective concentration (EC50) to more complex methods, such as drug sensitivity scoring (DSS). DSS is a recently developed method to quantitatively score differential drug sensitivity for individual anti-cancer therapies. This can be widely applied to experimental settings regardless of technical variability . CompareAI is poised to disrupt how big data is analysed and will benefit cancer management, including new drug discovery, drug repurposing and optimum dose administration . AI acceA number of studies have demonstrated that the new AI technology, quadratic phenotypic optimization platform (QPOP), which uses high order polynomial relationships to model complex biological events is very useful in optimizing drug combination therapy design by remarkably reducing the number of experiments needed ,57. ThisCURATE.AI, an AI-derived, indication-agnostic and mechanism-independent technology platform to provide a dynamic dosing optimisation throughout the course of treatment, has been recently developed based on data collected exclusively from the treated individual . Its appPrecision medicine aims to achieve timely tailored medicine to be administered for a particular patient . TreatmeHTS-based DST has been recently employed to rapidly identify personalized therapies for blood cancer patients and proved to be clinically implementable ,49. SeveThe Beat AML clinical trial (NCT02927106) demonstrated the integrative use of NGS to assign tailored treatment within 7 days for individual elderly AML patients. This is built on the largest-to-date dataset that integrates sequencing data (2000 most variably expressed genes) from 562 patients and DST data  from 363 patients. The dataset encompasses the documentation of clinically relevant gene mutations and allows the identification of potential therapeutics for AML patients . The resCombination therapies are critical to simultaneously target vulnerabilities in a cancer, and reduce the incidence of therapy resistance. HTS-based DST using PDCs followed by QPOP and CURATE.AI to identify optimal drug combinations and dosing, together with incorporating genomic and transcriptomic profiling to the DST to create a functional taxonomy based on comprehensive drug response and mutation profile will be an important next step toward devising new treatment strategies in blood cancer . This inAdvances in high-throughput technologies have had a positive impact on several facets of personalized medicine in AML and other cancers . Several


White-Sutton (WHSUS) is a recently recognized syndrome caused by mutations of the POGZ gene. Approximately 70 patients have been reported to date. Intellectual disability, hypotonia, behavioral abnormalities, autism, and typical facial dysmorphisms are recognized as WHSUS features; however, still few patients receive a comprehensive psychometric, behavioral and neurological examination. In this report, we describe the pediatric, dysmorphological, neurological, psychometric and behavioral phenotype in a new WHSUS patient due to a novel heterozygous POGZ mutation, highlighting the distinctive epileptic phenotype and the cognitive pattern.The patient, an 8 years-old girl, presented history of hypotonia, motor and speech delay, and distinctive facial features. The diagnosis of WHSUS followed the identification of the de novo variant p.Asp828GlyfsTer36 (c.2482dupG) in the POGZ gene. The patient showed a distinctive neurological phenotype with the occurrence of both paroxysmal not-epileptic events in the first 6 months of age and EEG abnormalities without evidence of clinical seizures after the first year of age. Psychological and behavioral testing highlighted moderate intellectual and communication deficit, mild autism spectrum and visual-motor integration deficit.This is the first described case of WHSUS with a co-existence of paroxysmal not-epileptic events and abnormal EEG without seizures in the same patient. Together with the available literature data, this observation suggests that paroxysmal not-epileptic events could be more frequent than expected and that this feature belongs to the WHSUS phenotypic spectrum. Autism is a known comorbidity of WHSUS but is still poorly investigated. Specific clinical testing could help detect also mild autistic phenotypes and better define autism prevalence in POGZ-related syndrome. Special attention should be given to symptoms such as stereotypies, social withdrawal, and hyperactivity that, when present, should be considered as possible signs of autism symptoms. The dissection of the neurological and behavioral phenotype is crucial for individualized therapies tailored to patient’s needs. White-Sutton  is a recently recognized syndrome caused by mutations of the POGZ (pogo transposable element-derived protein with zinc finger domain) gene, encoding for a multidomain nuclear protein that regulates chromatin remodeling, chromosome segregation and mitotic progression, making the majority of cells to prematurely exit mitosis with consequent depletion of neurogenic progenitor cells .WHSUS is characterized by developmental delay, intellectual disability, hypotonia, behavioral abnormalities, autism, and typical facial dysmorphisms . PatientThe epileptic phenotype in WHSUS is an additional clinical feature deserving further investigation. To the best of our knowledge, only 14 patients with WHSUS and epilepsy were reported in the literature. Medical reports plus EEG were available in 7 patients –8; amongHere we report the pediatric, dysmorphological, neurological, psychometric and behavioral phenotype of a new WHSUS patient due to a novel heterozygous POGZ mutation, highlighting the distinctive epileptic phenotype, characterized by both paroxysmal not-epileptic events and EEG abnormalities without epileptic seizures, and the cognitive pattern.The patient was the second child of two Caucasian non consanguineous parents. She was born by caesarean section and the perinatal history was uneventful. Her sister was affected by selective mutism. Since the first months of life, the patient presented hypotonia with consequent delay of the developmental milestones as she could sit without support at 12 months and move the first independent steps at 22 months. The child pronounced her first words at 13 months, but never achieved appropriate language skills. Bowel and bladder continence was gained at 4 years old. At the age of 3 and 6 months, the patient experienced two paroxysmal not-epileptic events characterized by lower and upper limbs stiffness, reduced response to external stimuli and eye deviation, lasting few seconds. A first sleep electroencephalogram (EEG) at this time (6 months) showed a slow background cerebral activity without epileptic abnormalities   showed aMutations in the POGZ gene were identified as a novel genetic cause of developmental disorders in 2015 , 18. SinThe present case further defines the mutational and clinical spectrum of POGZ-related syndrome. Besides the association of typical facial features, hypotonia, cognitive impairment and speech delay, some elements of her clinical history should be underlined. In her early life, the patient experienced two paroxysmal not-epileptic events with normal EEG and a later onset of EEG abnormalities in the absence of clinical seizures. To date, the co-existence in the same patient of paroxysmal not-epileptic events and abnormal EEG without seizures has never been reported in the literature. Paroxysmal not-epileptic events were reported in one Italian patient : the chiCompared with literature data, this case confirms the presence of a behavioral profile characterized by internalizing problems, intellectual and communication deficit , 5. In aFinally, patients with WHSUS present impairment of fine motor skills. Our data suggest that fine motor skills deficit may be a consequence of deficient visual-motor integration rather than of general dyspraxia.In conclusion, the dissociation between convulsive episodes and EEG anomalies suggests the importance of a periodic neurological evaluation and EEG monitoring in all patients affected by WHSUS. All patients should also receive a neuropsychological evaluation and a specific testing to precociously detect Autism Spectrum Disorders for individualized therapies tailored to patient’s needs. Special attention should be given to symptoms such as stereotypies, social withdrawal, and hyperactivity that, when present, should be considered as possible signs of autism symptoms rather than not-specific behavioral disorders.