Navigating the Interplay of Sickle Cell Vasculopathy and Moyamoya Cerebrovascular Changes: A Case Report.

Sickle cell disease (SCD) is a hereditary hemoglobinopathy that can lead to progressive vasculopathy, increasing the risk of cerebrovascular complications. Moyamoya syndrome (MMS), a rare disorder characterized by stenosis of the internal carotid arteries, can occur in SCD patients due to chronic endothelial damage and inflammation. The coexistence of these conditions can result in severe cerebrovascular complications, presenting unique diagnostic and therapeutic challenges. We present a 35-year-old African American male with a complex interplay of advanced SCD and MMS, manifesting as extensive cerebrovascular disease and recurrent ischemic strokes. A CT angiogram (CTA) of the head showed diffusely decreased caliber of the right M1 segment, appearing worse compared to prior studies. CTA of the head and neck demonstrated a new cut-off of the distal right M3 segment with an asymmetric paucity of arborizing vessels within the right middle cerebral artery (MCA) distribution, consistent with progressive sickle cell vasculopathy and also demonstrated abnormal dilated collateral vessels. Further imaging with MRI exhibited multiple prior ischemic strokes in various vascular territories despite previous revascularization surgery with a left superficial temporal artery to MCA bypass. The patient's progressive cerebrovascular disease was attributed to sickle cell vasculopathy exacerbated by MMS, resulting in compromised cerebral perfusion through distinct pathological mechanisms. Management involved a multidisciplinary treatment approach, including chronic transfusions, antiplatelet therapy, surgical revascularization with extracranial-intracranial bypass, seizure management, and neuropsychiatric support. Despite maximal therapy, the patient experienced recurrent cerebrovascular events and progressive neurological deficits, highlighting the challenges in controlling these intertwined disease processes. It signifies the importance of early recognition of this rare co-occurrence and implementation of prompt multidisciplinary treatment to improve outcomes.