Objective:

To describe an uncommon CADASIL presentation, concomitant spinal cord lesions that initially mimicked a neuroinflammatory demyelinating disorder.

Background:

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a NOTCH3-mediated small-vessel arteriopathy classically presenting with migraine with aura, subcortical ischemic events, psychiatric symptoms, and progressive cognitive decline. Spinal cord involvement and inflammatory CSF profiles are unusual and may lead to misdiagnosis.

Design/Methods:

Single-patient case report with review of clinical course, neuroimaging, CSF studies, and confirmatory genetic testing.

Results:

A 47-year-old man with vitiligo, Hashimoto thyroiditis, and tobacco use presented with right-hand incoordination and right-lower facial paresthesias a decade prior; MRI then showed innumerable periventricular and subcortical T2/FLAIR hyperintensities with small cystic encephalomalacia in the corona radiata. He now presents with 3 days of left-sided weakness and gait instability. Exam showed left-leg 4/5 strength, diffuse hyperreflexia with bilateral ankle clonus, mild lower-extremity spasticity, distal vibration loss, and positive Romberg. MRI brain revealed an acute diffusion-restricting lesion in the right-corona radiata plus extensive leukoencephalopathy involving corpus callosum, periventricular regions, and anterior temporal lobes. Cervical/thoracic MRI demonstrated subtle central cord T2 hyperintensities. CSF showed mildly elevated protein and three mirror-pattern oligoclonal bands; serum anti-SSA was mildly elevated. High-dose IV methylprednisolone produced no clinical benefit. He was initially diagnosed with relapsing–remitting multiple sclerosis. Subsequent disclosure of a sister with genetically confirmed CADASIL and a paternal family history of early stroke, dementia, and psychiatric illness prompted NOTCH3 testing, which was positive. He was transitioned to secondary stroke prevention no further infarcts have occurred to date.

Conclusions:

CADASIL rarely presents with spinal cord T2 lesions and mild inflammatory biomarkers, confounding the distinction from MS. Failure to improve with corticosteroids, anterior temporal lobe involvement on MRI, early-age strokes, and a strong family history should trigger NOTCH3 testing. Early recognition prevents misclassification and guides appropriate cerebrovascular risk management and neuropsychiatric support.