Abstract
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare genetic disorder due to a NOTCH 3 mutation on chromosome 19 resulting in a small vessel disease that may mimic many other neurological disorders like migraine, stroke, transient ischaemic attack (TIA), dementia and psychiatric illnesses. The disease is confirmed by genetic testing and other investigations like MRI and skin biopsy are also helpful. Here, we present a 43-year-old male with a confirmed CADASIL through genetic testing, who was initially diagnosed as having multiple sclerosis due to recurrent attacks of focal neurological deficits in the form of weakness and vertigo and other progressive features like mental slowing and difficulties in performing the usual tasks at work, He had a strong family history of neurological illnesses from his mother's side that made us think of an alternative diagnosis.