Typical Clinical Presentation of Moyamoya Disease

Clinical History

A 35 years old gentleman presented with sudden onset of left facial weakness and left arm weakness and numbness. His past medical history revealed 10 episodes of similar symptoms over a period of 20 months prior to his presentation.

Imaging Findings

Initial investigations including haematology, clotting profile, urea, electrolytes and liver function tests were normal. Carotid Ultrasound scan showed no major atheroma at the origin of the internal carotid arteries. CT brain scan showed multiple areas of established infarction in the right middle cerebral artery and both anterior cerebral artery territories. CT Angiography demonstrated bilateral occlusion of the proximal middle and anterior cerebral arteries. Conventional Cerebral Angiography includes Right Carotid Angiography, standard views, showed complete occlusion of the terminal branches of the internal carotid artery with extensive abnormal network of collateral vessels. Left Carotid Angiography demonstrated similar picture with occlusion of the distal internal carotid artery and its proximal intracranial branches. The left vertebral injection showed remarkable retro-grade filling of the anterior circulation via collaterals. Angiography of the carotid bifurcation revealed no proximal stenosis and the distal arteries do not appear beaded or narrowed to suggest a wide spread vasculitis. On the bases of radiology appearance and clinical features, the diagnosis of Moyamoya disease was made.

Discussion

Moyamoya disease is a progressive vascular occlusive disease involving the distal internal carotid artery and the proximal circle of Willis. Collateral vessels develop to compensate for the slowly progressive stenosis. These enlarged collaterals appear as a “puff of smoke” on angiography, which gives the disease its name. Although this disease occurs predominantly in Japanese, its occurrence has also been reported in other countries. The symptoms and clinical course vary widely from asymptomatic to transient events to severe neurological deficits. Both children and adults develop moyamoya disease, but their clinical features often differ. The most common clinical manifestation is motor-type ischaemic episodes, although it may also be accompanied by intracerebral haemorrhages. Moyamoya disease sometimes occurs along with other disorders such as Down,s syndrome, Marfan syndrome, Graves disease, Atherosclerotic disease, fibromuscular dysplesia, cranial trauma and radiation injury. Cerebral angiography is the gold standard for diagnosis. The following findings support the diagnosis: Bilateral stenosis or occlusion of the terminal portion of the internal carotid artery or the proximal portion of the anterior and middle cerebral arteries and abnormal network of parenchymal and leptomemingeal collateral vessels. MR angiography is capable of non-invasively delineating the status of the major intracranial arteries. Other imaging modalities such as SPECT, PET and Perfusion MR are useful to obtain information on cerebral blood flow and changes in haemodynamics in Moyamoya disease.

Differential Diagnosis List

Final Diagnosis

Moyamoya Disease

URL:	https://www.eurorad.org/case/5746
DOI:	10.1594/EURORAD/CASE.5746
ISSN:	1563-4086