Moyamoya disease | |
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T1-weighted MR image of moyamoya disease. Flow void in the basal ganglia is indicated by the arrow. | |
Specialty | Neurosurgery |
Symptoms | Headache, Seizures, Weakness, Numbness or paralysis in your face, arm or leg, typically on one side of your body, visual disturbances, Difficulties with speaking or understanding others (aphasia), Cognitive or developmental delays, involuntary movements.[1] |
Complications | permanent damage to the brain, seizures, paralysis, vision problems, speech problems, movement disorders and developmental delays.[1] |
Diagnostic method | Magnetic resonance imaging (MRI), Computerized tomography (CT) scan, Cerebral angiogram, Positron emission tomography (PET) scan or single-photon emission computerized tomography (SPECT), Electroencephalogram (EEG), Transcranial Doppler ultrasound.[1] |
Medication | Blood thinners, Calcium channel blockers, Anti-seizure medications.[1] |
Moyamoya disease is a disease in which certain arteries in the brain are constricted. Blood flow is blocked by constriction and blood clots (thrombosis).[2] A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are small, weak, and prone to bleeding, aneurysm and thrombosis. On conventional angiography, these collateral vessels have the appearance of a "puff of smoke", described as moyamoya (もやもや) in Japanese.[2]
When moyamoya is diagnosed by itself, with no underlying correlational conditions, it is diagnosed as moyamoya disease. This is also the case when the arterial constriction and collateral circulation are bilateral. Moyamoya syndrome is unilateral arterial constriction, or occurs when one of the several specified conditions is also present.[3] This may also be considered as moyamoya being secondary to the primary condition. Mainly, occlusion of the distal internal carotid artery occurs. On angiography, a "puff of smoke" appearance is seen, and the treatment of choice is surgical bypass.