Stroke in children with sickle cell anaemia in Mulago Hospital

Abstract

Background: Sickle cell anaemia (SCA) is a leading cause of child morbidity and mortality affecting 4% of all newborns in Uganda. Over 7000 SCA patients are registered in Mulago hospital. Stroke is a catastrophic complication of SCA: 10% of patients with SCA will have had a stroke by the age of 20 years. Hitherto there has been limited information on SCA stroke in Uganda. Objective: To describe the clinical presentation of children with SCA stroke and hematological indices in those with and without stroke. The secondary objective was to describe interventions in SCA children with and without stroke. Methods: One hundred and eighty four SCA children aged 2-18 years attending the sickle cell services of Mulago Hospital in Uganda were enrolled in this cross sectional study from February to June 2011. Forty six children with stroke were compared with 138 without stroke. Data on the socio-demographics, history and physical examination was collected on a standardized questionnaire. Blood tests included a complete blood count and hemoglobin electrophoresis. Data was analyzed using Stata Version 10 Stata Corp LP, Texas USA. Data was summarized in tables and charts. The chi square and Fisher’s exact test with odds ratios and 95% confidence intervals (CI) were used where appropriate. Results: One hundred and eight four SCA patients were recruited into this study: 46 with stroke and 138 without stroke. Thirty five percent of the participants were below five years of age. The M: F ratio was 1:1.The median age for SCA stroke patients was 8 years (IQR 5-11) and 8 years (IQR 5-11) for those without stroke. The median age at first stroke was 4 years (IQR 2-6). The main symptoms of children with SCA stroke included behavior changes, headache and seizures. Findings on physical examination included hemiplegia, aphasia, and limb ataxia. Overall hematological indices, other than HbS level (mean HbS level - 72% [SD 24.5]), were not significantly different between those with SCA stroke and those without stroke. Four of the 46 children with SCA stroke had an HbS<30%, versus 0/138 without stroke (p=0.004). Children with SCA stroke (44/46) were more likely to have received a blood transfusion than those without stroke (99/138): OR 8.6 (95%CI 2.0, 37.5). Mean number of blood transfusion in both groups was 4.9 [SD 4.5]. Children with SCA stroke (33/46) were more likely to have had multiple transfusions than those without stroke (62/138): OR 3.1 (95% CI 1.5, 6.6). Very few had had pneumococcal vaccine or received hydroxyurea. Conclusion: Common symptoms in sickle cell anaemia children with stroke include behavior change, headache and seizures; while clinical signs include hemiplegia, aphasia and limb ataxia. Only a very small number of the SCA children, regardless of their stroke status, had HbS<30%. Children with SCA stroke were more likely to have received a blood transfusion than those without stroke probably as a consequence of stroke management. A high index of suspicion and clinical assessment of children with neurological symptoms is essential for the diagnosis of SCA stroke. Recommendation: In order to design effective strategies for the prevention of SCA stroke in our setting, there is need for studies to establish the risk factors for stroke among children with sickle cell anaemia.