Incidence of overt and covert neurological damage in children with sickle cell disease.

We studied 25 patients with sickle cell disease (15 with HbSS; 8 with HbSC and 2 with HbS beta degree) using neurological examination as a marker of overt and computed tomographic (CT) scan as a marker of covert neurological damage. Of the 25 patients, 5 (20%) had evidence of cerebral infarcts on CT scan, but only 4 of these 5 patients had neurological signs. Neurological problems were only seen in patients with HbSS. We could not identify any haematological risk factors, but in this small group of HbSS patients a crisis rate greater than 1 per year of follow up was associated with a significant risk of neurological damage.