Cognitive Dysfunction in Children and Adolescents with Sickle Cell Disease without Evidence of Stroke: Preliminary Results.

Sickle cell disease (SCD) is the most frequent cause of stroke in children. It is possible that cognitive dysfunction occurs in the absence of identifiable stroke due to silent cerebrovascular disorders.

To evaluate SCD compromises cognitive functions of patients with no radiological nor clinical evidence of stroke.

Thirty eutrophic children with SCD, with normal neurological examination and imaging (brain CT) and without past cerebrovascular disease were submitted to neuropsychological assessment between 2002 and 2008. The neuropsychological battery included the following tests: WISC-III, BTN (battery of neuropsychological tests, assessing laterality), Rey complex figure (visual perception and memory), and behavioral screening for ADHD, learning disorders and antisocial behavior.

66.7% of patients were male. The average age of patients was 9.6 years (6 - 15 years). The mean total IQ was 78.8 (50 - 105) and the executive IQ was 77.9 (47 - 108), both at the borderline limit. The verbal IQ mean was 84.9 (55 - 113), on lower average. Verbal comprehension verbal was on average 87.4 (58 - 115). The results of visual memory was at the lower limit of normal (mean percentile 16 to 18). There was no correlation between the rates of behavior disorders (inattention, hyperactivity, learning difficulties and conduct disturbance) and IQ results. There was no statistically significant difference between the results of males and females or between age groups. 40% of the sample had not developed manual preference.

The subjects of this sample showed significant cognitive impairment in the absence of clinical or radiological evidence of cerebrovascular disease. The study has limitations as the sample size, the imaging technique used and neuropsychological battery comprehensiveness, but the results are quite suggestive of a relationship between SCD and cognitive impairment. The research group is developing a study with a larger sample (100 patients) to clarify the correlations between these findings. This will be important to outline earlier neuroprotective measures, which will provide improvements in neurodevelopment, learning, quality of life and social inclusion.

No relevant conflicts of interest to declare.