Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL): A Diagnosis to Consider in Atypical Stroke Presentations

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a hereditary cerebral arteriopathy caused by a neurogenic locus notch homolog protein 3 (NOTCH3) gene mutation. This article describes the case of a man in his early 40s who experienced sudden onset temporary left-sided weakness and facial numbness that resolved in two hours, along with residual weakness in the upper and lower limbs. There was a family history of CADASIL with both his mother and brother having experienced strokes. Clinical investigations on admission were unremarkable including a young stroke screen and computed tomography (CT) of the brain. On CT angiography, there was no evidence of significant carotid artery stenosis. Subsequent cerebral magnetic resonance imaging (MRI) revealed an acute infarction in the right corona radiata extending into the right basal ganglia, with the fluid-attenuated inversion recovery (FLAIR) images revealing considerable bilateral symmetrical white matter hyperintensity in the frontal, parietal, and anterior temporal lobes. Based on his clinical presentation, strong family history, and brain MRI findings, a diagnosis of CADASIL was suspected. He received antiplatelet medication for an acute stroke and later underwent genetic testing, which revealed the presence of a NOTCH3 gene mutation.