Cerebral vascular abnormalities in pediatric patients with sickle cell disease after hematopoietic cell transplant.

OVERVIEW: Stroke is a common sequela of sickle cell disease (SCD). Patients with SCD who undergo hematopoietic stem cell transplantation (HSCT) with successful engraftment will not experience sickling. This ameliorates one aspect of stroke risk; however, the significance of preexisting cerebrovascular abnormalities remains unclear. METHODS: We performed a literature search for neurological outcomes following HSCT for SCD. We searched for relevant neuroimaging and neurosurgical protocols. We identified 4 unique studies encompassing 196 patients. Of these, 81 had a history of a stroke, transient ischemic attack (TIA), cognitive dysfunction or cerebrovascular abnormalities identified by pretransplant neuroimaging, achieved stable engraftment, and had long-term follow-up. RESULTS: Of the 81 patients, 1 had peritransplant (10 days prior transplant to 50 days posttransplant) TIA. One had posttransplant TIA within 36 to 72 months. None had strokes. Forty-five underwent cerebral imaging at nonuniform intervals. Among this group, 32 (71%) had stable cerebrovascular abnormalities on imaging, 6 (13%) had improvement, and 7 (16%) showed worsening. CONCLUSIONS: Cerebrovascular abnormalities identified on neuroimaging may stabilize, improve, or worsen in patients after successful HSCT. Some patients may have neurological events such as TIA. Neurological outcomes in children with SCD post-HSCT have been inadequately studied.