Risk Factors for Intracranial Hemorrhage in Children with Sickle Cell Anemia.

Background: Intracranial hemorrhage (ICH) is an uncommon, but devastating, complication of sickle cell disease (SCD) with mortality from 30 to 65%. Most reported cases are in adults; little is known about children. Proposed risk factors include previous ischemic stroke, aneurysms, low steady-state hemoglobin, high steady-state leukocyte count, acute chest syndrome, and hypertransfusion.

Methods: Retrospective case-control study designed to characterize and evaluate risk factors for ICH among children with SCD age < 19 years hospitalized at Johns Hopkins Children’s Center from January 1979 to March 2004. Cases had SCD and ICH (intraparenchymal (IPH), subarachnoid (SAH), or intraventricular (IVH) hemorrhage confirmed by neuroimaging or analysis of cerebrospinal fluid; traumatic subdural and epidural hemorrhages were excluded). Controls had SCD and ischemic stroke (focal neurological deficits with corresponding cerebral infarcts by neuroimaging). Both were identified by searching the hospital discharge database using ICD-9 codes for acute stroke and SCD and reviewing the Division of Pediatric Hematology’s records. ACS was defined as a new pulmonary infiltrate and two of the following: chest or rib pain, dyspnea, fever, tachypnea, grunting, nasal flaring, or retractions. Blood pressure was adjusted for age, sex, and hemoglobin genotype.

Results: We identified 7 cases (mean age=11.2 years, range 2 to 16 years) and 9 controls (mean age 6.2 years, range 2 to 8 years). As expected, cases were significantly older than controls (p<0.01). All cases and controls had sickle cell anemia. Cases presented with impaired mental status (5/7), bradycardia (5/7), headache (4/7), and emesis (3/7). They often had multiple sites of hemorrhage (5/7) and died during the initial hospitalization (4/7). Five had IPH involving the frontal, parietal, and/or temporal lobes (2 of the patients with IPH also had SAH, 1 had IVH and 1 had both SAH and IVH). Two additional patients had SAH (one also with IVH). Most cases and controls had elevated systolic blood pressure at the time of stroke (4/7 cases, 8/9 controls). Cases had lower steady-state hemoglobin (mean±SE 7.1±0.3 g/dl vs. 7.7±0.4 g/dl), lower steady-state blood pressures (systolic 104±9 vs. 117±5 mm Hg, diastolic 50±5 vs. 61±5 mm Hg) and higher steady-state leukocyte counts (16,590±2823/ul vs. 13,851±2184/ul) than controls, but these differences were not statistically significant. Mean hemoglobin concentration was increased 2.8 g/dl (39.9%) from steady-state at the time of stroke in cases and was unchanged in controls (p=0.08). Other events in the two weeks before ICH associated with increased odds of ICH included transfusion (simple in 5 cases, erythrocytapheresis in 1), ACS (3 cases), and corticosteroid administration (high-dose dexamethasone for ACS in 2, stress doses for possible adrenal insufficiency in 1).

Conclusions: In this group of children with SCD, ICH was associated with antecedent events including transfusion and possibly corticosteroids. Mortality was similar to that of adults with SCD and ICH. Limitations of this study include the small sample size and the retrospective design. The contribution of antecedent events to ICH in children with SCD deserves further evaluation.

Odds Ratios of Intracranial Hemorrhage For Events in the Last 14 Days