Neural oscillations in antipsychotic-naïve patients with a first psychotic episode.
OBJECTIVES
In chronic schizophrenic psychoses, oscillatory abnormalities predominantly occur in prefrontal cortical regions and are associated with reduced communication across cortical areas. Nevertheless, it remains unclear whether similar alterations can be observed in patients with a first episode of psychosis (FEP), a state characterised by pathological features occurring in both late prodromal patients and initial phases of frank schizophrenic psychoses.


METHODS
We assessed resting-state electroencephalographic data of 31 antipsychotic-naïve FEP patients and 29 healthy controls (HC). We investigated the three-dimensional (3D) current source density (CSD) distribution and lagged phase synchronisation (LPS) of oscillations across small-scale and large-scale brain networks. We additionally investigated LPS relationships with clinical symptoms using linear mixed-effects models.


RESULTS
Compared to HC, FEP patients demonstrated abnormal CSD distributions in frontal areas of the brain; while decreased oscillations were found in the low frequencies, an increase was reported in the high frequencies (P < 0.01). Patients also exhibited deviant LPS in the high frequencies, whose dynamics changed over increasing 3D cortico-cortical distances and increasing psychotic symptoms.


CONCLUSIONS
These results indicate that in addition to prefrontal cortical abnormalities, altered synchronised neural oscillations are also present, suggesting possible disruptions in cortico-cortical communications. These findings provide new insights into the pathophysiological mechanisms of emerging schizophrenic psychoses.
['Ramyead|Avinash|A|', 'Studerus|Erich|E|', 'Kometer|Michael|M|', 'Heitz|Ulrike|U|', 'Gschwandtner|Ute|U|', 'Fuhr|Peter|P|', 'Riecher-Rössler|Anita|A|']
D000293:Adolescent D000328:Adult D016022:Case-Control Studies D004569:Electroencephalography D005260:Female D006801:Humans D021621:Imaging, Three-Dimensional D016014:Linear Models D008279:Magnetic Resonance Imaging D008297:Male D017397:Prefrontal Cortex D011618:Psychotic Disorders D012559:Schizophrenia D012565:Schizophrenic Psychology D055815:Young Adult
psychosis EEG Schizophrenia biomarkers phase synchrony