CADASIL can mimic multiple sclerosis.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) can be confused with multiple sclerosis (MS). We report a man with a father diagnosed with MS via magnetic resonance imaging (MRI). The index patient was subsequently diagnosed with MS after MRI for evaluation of migraine headaches. Genetic testing confirmed the CADASIL diagnosis. CADASIL is characterized by a history of migraine headaches, mid-adult onset of progressive cerebrovascular disease, diffuse white matter changes, and dementia. The mutation involves the Notch3 gene which changes a codon for arginine to cysteine at amino acid position 90.