Cerebral Vasoreactivity in Children with Sickle Cell Disease: A Transcranial Doppler Study.
BACKGROUND
Impairment of vasodilatory capacity reflecting reduced cerebrovascular reserve was previously shown in adults with sickle cell disease (SCD) and might play a role in the pathophysiology of stroke in such patients. We examined the hypothesis that children with SCD would also have a higher frequency of impaired cerebral vasoreactivity when compared with healthy age- and gender-matched controls.


METHODS
Patients were recruited from our hematology outpatient clinic. All SCD patients aged 10-18 years without a history of symptomatic stroke as well as age- and gender-matched healthy children were evaluated with transcranial Doppler (TCD) ultrasonography, with breath-holding maneuver. Breath-holding index (BHI) was calculated by dividing the percentage increase in mean flow velocity occurring during breath holding by the length of time subjects hold their breath after a normal inspiration. BHI was considered abnormal if less than .69.


RESULTS
TCD was performed in 42 patients (mean age 12.7 ± 2.2 years) and 20 controls (mean age 13.90 ± 3.04 years). Blood flow velocities were higher in patients with SCD than in controls in all arteries evaluated (P < .001). BHI values in patients with SCD were significantly lower than in control subjects (1.27 ± .65 versus 1.74 ± .15, P = .013 on the left and 1.16 ± .45 versus 1.61 ± .11, P = .002 on the right). BHI was abnormal in 19% of the patients and in none of the controls, P = .036.


CONCLUSIONS
Children with SCD may have impaired cerebral vasoreactivity, with low BHI values suggesting a reduced autoregulation capacity.
['Macedo-Campos|Rejane de Souza|RS|', 'Adegoke|Samuel Ademola|SA|', 'Figueiredo|Maria Stella|MS|', 'Braga|Josefina Aparecida Pellegrini|JAP|', 'Silva|Gisele Sampaio|GS|']
D000293:Adolescent D000367:Age Factors D000755:Anemia, Sickle Cell D001783:Blood Flow Velocity D062485:Breath Holding D016022:Case-Control Studies D002536:Cerebral Arteries D002560:Cerebrovascular Circulation D002648:Child D005260:Female D006706:Homeostasis D006801:Humans D008297:Male D011237:Predictive Value of Tests D018617:Ultrasonography, Doppler, Pulsed D017585:Ultrasonography, Doppler, Transcranial D014664:Vasodilation
cerebral vasoreactivity children sickle cell disease transcranial Doppler Breath-holding index