Bilateral Middle Cerebellar Peduncle Sign in a Patient with Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy and Coronavirus Disease 2019

A 59-year-old man without risk factors for atherosclerosis was diagnosed with coronavirus disease 2019 (COVID-19). Four days later, he developed dysarthria and gait disturbance. Neurological examination revealed slurred speech, ataxia, and mild cognitive decline. Brain magnetic resonance imaging revealed multiple infarcts in the bilateral middle cerebellar peduncles and leukoencephalopathy, indicating the diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Genetic testing confirmed a pathogenic NOTCH3 variant (c.505C>T, p.Arg169Cys) (NM_000435.3). A skin biopsy supported the diagnosis. He was treated with cilostazol and after three months of rehabilitation, he regained an independent walking ability. COVID-19 increases the risk of ischemic stroke in CADASIL patients, with bilateral middle cerebellar peduncle infarctions being notable in the present case.