Outcome of stroke in patients with sickle cell disease

ABSTRACT

Cerebral vasculopathy is a major cause of morbidity in sickle cell disease (SCD). We report the first UK population-based study of stroke in SCD. Of 669 SCD patients (HbSS 429, HbSC 193, HbS-thalassaemia 48, HbSO 1) followed at the King's College hospital between 1970 and 1995, 21 (3.1 percent) developed stroke. A further ten patients were referred. 29 had HbSS and 2, HbSC. 3 (10 percent) suffered subarachnoid haemorrhage, the remaining 28 strokes were ischaemic. Median age at initial stroke was 6 years (19 mo- 31 yr) with 24 (80 percent) patients aged >10. Precipitating factors included parvovirus associated aplastic crisis in 2/25 98 percent) evaluable patients and bacterial meningitis in 2 (8 percent). 9 (36 percent) patients experienced transient neurological disturbance prodromally. 27 (87 percent) presented with paresis, 5 (16 percent) cranial nerve defects. 11 (35 percent) dysphasia and 3 (10 percent) seizures. No patient died during the acute episode. Patients with stroke had significantly lower Hb and higher WCC at age 1 compared to matched controls. Exchanged transfusion was performed with 26 patients following which 15 (58 percent) recovered neurologically. 19 patients subsequently entered a transfusion programme to maintain HbS <30 percent. Transfusion was stopped in 10 patients. Of these, 6 (60 percent) had recurrent stroke at a median of 4.5 months. A similar recurrence rate (50 percent) was observed among patients who did not receive regular transfusion whilst no patient maintained on monthly transfusions suffered further stroke. Recurrence was more common in patients suffering initial stroke at an early age and in whom no trigger was identified. Median follow-up after initial stroke is 8 years. 14 (45 percent) patients have no residual neurological deficit, 6 (19 percent) are severely disabled, 13 (42 percent) have learning disabilities and 7 (23 percent) epilepsy. There were two deaths in both patients with recurrent stroke. 1 patient with moyamoya-type disease has undergone extracranial-intracranial bypass and 1 allogeneic-BMT. In conclusion, whilst transfusion is effective in prevention of further stroke, cessation is associated with a high rate of recurrence which frequently results in severe physical and/or neuropsychological disability. The 6.5 percent mortality following stroke supports the rationale for early consideration of allogeneic-BMT in these patients. (AU)