Introduction Cerebral Autosomal Dominant Angoipathy with Subcortical Infarcts and Leucoencephalopathy is a disorder caused by mutations in the NOTCH 3 gene. It is the most common cause of heritable stroke. Patients commonly present with migraine. Case report: we present a case of 31 year old female who came to neurology clinics with a history of recurrent attacks of migraine with aura of the hemiplegic type. These episodes began in her early twenties. She had no family history of note. Her examination was normal. Impression initially was felt to be migraine with aura.

After agreeing to a treatment plan with the patient, she mentioned that her brother was also seen in Neurology clinics and that he was investigated with an MRI brain. His MRI images had shown wide spread white matter changes.

We decided to perform an MRI brain which revealed subcortical and right anterior temporal white matter high signals. Genetic testing (NOTCH 3) confirmed diagnosis of CADASIL.

Conclusion prevalence of CADASIL may be underestimated partly due to underdiagnoses, especially in patients presenting with migraine. Every attempt to gain an appropriate family history should be made to avoid misdiagnosis.