Tara Bahramipour;
Newark Beth Israel Medical Center
Ibraheem Shaikh;
Newark Beth Israel Medical Center
Kenneth Brock;
New York Presbyterian-Columbia
Anatoliy Vaysberg;
Newark Beth Israel Medical Center
Background
Sickle cell disease (SCD), a hereditary blood dyscrasia, is one of the most common genetic disorders worldwide. As a multiorgan disease with various systemic manifestations, SCD can have devastating neurologic complications. Vascular occlusion in SCD may lead to repeated cerebral infarction, autoregulatory dysfunction and vasospasm, and pathologic neovascularization. Imaging plays a pivotal role in evaluation and management of SCD-related neurologic disease. We examined recent magnetic resonance imaging (MRI) studies at our institution for patients with SCD and neurologic sequelae. We highlighted distinguishing characteristics that are frequently seen in such patients.
Educational Goals / Teaching Points
Individuals with SCD undergo imaging at significantly higher rates than the general population due to a variety of complications and morphologic sequelae of SCD, that require prompt diagnosis and evaluation. MRI is the preferred imaging modality. Episodic polymerization of HbS in SCD patients results in adherence to vessel endothelium and subsequent entrapment and vaso-occlusion. Repeated episodes result in inflammatory changes that promote fibrocellular proliferation of vessel intima, further vasoconstriction, and consequent episodes of polymerization. In the brain, these changes are most often seen at the distal internal carotids, middle cerebral arteries, and anterior cerebral arteries. Ischemic stroke commonly develops as a consequence of this process. The primary goal is to understand uncommon neurologic complications of SCD including cerebral fat embolism, posterior reversible encephalopathy, and venous sinus thrombosis and its unique presentation on multimodality imaging.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Repeated episodes of intraluminal occlusion result in neovascularization with ill-defined collateral vessels, appearing radiographically similar to those seen in moyamoya vasculopathy (i.e., secondary moyamoya syndrome). Microaneurysms in such vessels predisposes to fatal hemorrhagic stroke. Surgical revascularization is used in advanced disease to bypass occluded vessels. Repeated episodes of (often subclinical) vaso-occlusion result in chronic ischemic changes in the brain. The resulting cortical volume loss is one of the most frequent complications of SCD. Other uncommon neurologic complications of SCD include cerebral fat embolism, posterior reversible encephalopathy, and venous sinus thrombosis.
Conclusion
Neurologic consequences of SCD arise from occlusive vascular disease and include multiple cerebral infarctions, autoregulatory dysfunction and vasospasm (e.g., posterior reversible encephalopathy), and pathologic neovascularization (moyamoya syndrome). Early imaging is vital for diagnosis and guides management.
