Moyamoya Disease Associated with Hyperhomocysteinemia: A Rare Cause of Stroke in Sub-Saharan Africa

Abstract

Introduction: Moyamoya disease (MMD) is a chronic cerebrovascular disorder characterized by progressive bilateral occlusion of the supraclinoid internal carotid artery (ICA) and its main branches, associated with the development of fine collateral networks, especially adjacent to the site of occlusion in the deep areas of the brain. MMD frequently occurs in East Asian populations, including pediatric and adult patients, and may lead to ischemic or hemorrhagic stroke, headache, epilepsy or transient ischemic attack. The majority is presumed to be of genetic origin and few cases of thrombophilia have been reported in MMD. We report a case of MMD in a young sub-Saharan African woman associated with Hyperhomocysteninemia (HHCys). Observation: A 33-year-old female was seen for aphasia, which had suddenly appeared fourteen days before, and was associated with memory impairment. She mentioned chronic headaches during the 10 previous years, of frontal seat, without migraine criteria. She had no history of hypertension, no obesity, no known dyslipidemia, and there was no family history of stroke. Neurological examination noted Wernicke’s aphasia, with discreet right central facial palsy, associated with memory impairment. The brain MRI revealed semi recent infarct in the left parietal lobe, sequelae in the left temporo-occipital and right frontal with lacunar ischemic lesions, associated with several foci of sub- cortical demyelination. MRA showed stenosis of the supraclinoid carotid arteries and their division branches. In addition, there was a stenosis of the posterior cerebral arteries, with a network of anastomosis at the level of the base of the skull. An investigation of thrombophilia showed hyperhomocysteinemia (HHCys). The diagnosis of moyamoya disease associated with hyperhomocysteinemia was mentioned. She was treated by Aspirin combined to folic acid. After a 3-year setback the patient was asymptomatic. Conclusion: MMD is a rare cause of stroke in sub-Saharan Africa. MRA should be performed whenever possible, as well as investigation for thrombophilia when it’s available. Combined antiplatelet agent with folic acid for ischemic stroke prevention is effective.