MOYAMOYA SYNDROME ASSOCIATED WITH ALTERNATING HEMIPLEGIA

Objectives: Moyamoya syndrome is a chronic cerebrovascular disease with bilateral stenosis of the arteries around the circle of Willis with prominent collateral circulation. An association with alternating hemiplegia is rarely mentioned.

Methods: We describe a 10-year-old adopted Chinese girl with normal psychomotor development (video presentation).

Results: Since the age of seven years she had recurrent left sided hemiparesis frequently accompanied by right sided headache. Provoking factors were hyperventilation and stress. Neurological examination between the attacks revealed no abnormalities. During hyperventilation provocation she feeled herself uncomfortable, yawned, got a left sided hemiparesis, urine incontinence and became unconscious. After 20 minutes her hemiparesis disappeared and she recovered after half an hour. An MRI brain showed no abnormalities. EEG examination after an attack showed bilateral high amplitude slow wave activity without epileptiform discharges. The diagnosis complex partial seizures was made. Anti-epileptic treatment had inadequate effect. At the age of 10, the girl also suffered from attacks with a right sided hemiparesis. Provoking factors at that time were playing her flute, singing, sitting in a rolling coaster and pain. An ictal EEG demonstrated symmetrical slow wave activity without epileptiform discharges. An MR angiography showed bilateral stenosis of the internal carotid arteries and Moyamoya syndrome was diagnosed. Neurochirurgical intervention was performed and she became extra-intracranial bypasses. At this moment she has no left sided attacks and a decreasing number of right sided attacks.

Conclusion: Alternating hemiplegia and paroxysmal hemiplegia may be the first symptom of Moyamoya syndrome. Moyamoya syndrome should be considered in the differential diagnosis of alternating hemiplegic migraine, paroxysmal exercise-induced dystonia as well as complex partial seizures and transient ischaemic attacks.