OBJECTIVE:  Moya-moya disease (MMD) is a rare and chronic vasculopathy characterized by progressive stenosis at apices of the internal carotid artery (ICA) including the proximal anterior cerebral arteries and middle cerebral arteries (MCA). Moya-moya disease rarely causes seizures in children and cannot always be recognized easily. Seizures occur in approximately 5% of patients secondary to an ischemic lesion or hypoperfusion, usually starting in childhood. This patient has an angiographic appearance of moya-moya and down syndrome and hence classified as moya-moya syndorme (MMS). In this case report, we present a 9-year-old girl with down syndrome (DS) who presented with weakness and seizure.

CASE: A 9-year-old girl presented with acute onset of left-sided weakness with facial weakness and generelized clonic seizure. Birth history and family history were unremarkable. On physical examination, she had a mongoloid face with flattened nasal bridge and almond-shaped eyes suggestive of DS. There were weakness on left extremities with a motoric strength of 4 and left central facial nerve palsy. Electroencephalography shows slowing brain waves in the left frontal lobe. Brain MRI non contrast showed infarct at bilateral frontal lobe, lateral ventricle, bilateral corona radiata and basal ganglia. MRA showed occlusion at right distal internal carotid artery and bilateral middle cerebral artery with prominent collateral arteries at cysterna basal, perimesencephalic and basal ganglia. She was treated with aspirin, phenytoin, baclofen and folic acid. The patient was discharged with improvement and underwent regular physiotherapy.
CONCLUSION: Moya-moya disease is a rare vascular cause of childhood stroke and when associated with DS, it is diagnosed as MMS. The natural history of MMS tends to be progressive and patients often suffer cognitive and neurologic decline due to repeated ischemic stroke or hemmorhage while seizures worsens the prgonosis. Hence, awareness has to be raised for cerebrovascular events in patients with epilepsy.