Author(s)

E. Kirsch

Patient

male, 55 year(s)

presented with sudden onset right-sided sensorimotoric hemiparesis. Ultrasonography showed a total occlusion of the right internal carotid artery (ICA) at the level of the carotid bifurcation. Laboratory findings were normal. The patient’s previous history was irrelevant. Screening for tumor, rheumatologic, infectious, paraneoplastic or metabolic disorders was negative.

A patient presented with sudden onset right-sided sensorimotoric hemiparesis. Ultrasonography showed a total occlusion of the right internal carotid artery (ICA) at the level of the carotid bifurcation. Laboratory findings were normal.
The patient’s previous history was irrelevant. Screening for tumor, rheumatologic, infectious, paraneoplastic or metabolic disorders was negative.
Axial SE T1-weighted MR image of the brain shows acute bleeding in the centrum semiovale of the left hemisphere.
Axial MIP-MR angiography of the brain demonstrates an occluded ICA, anterior (ACA) and middle cerebral artery (MCA) on the right side. Occlusion of the left ACA and MCA, and intense signal of both posterior cerebral arteries (PCA) are seen. Some additional vessels at the level of the proximal PCA-portions are also visible.
Intra-arterial DSA of the brain includes left common carotid artery (CCA) arteriography, oblique projection which showed occlusion of the proximal ACA and MCA. Additional abnormal vascular network in the region of the basal ganglia is seen.
Right CCA-arteriography, AP projection , demonstrates total occlusion of the ICA and its intracranial main branches. Transdural anastomosis from the superficial temporal artery to the cortex is noted. Left vertebral arteriography, lateral projection , visualizes enlarged branches of the PCA sending leptomeningeal collateral vessels to the ACA and MCA territories. A marked basal vascular network is seen.
Based on the clinical and radiological features, the diagnosis of Moyamoya disease (MD) was made.

MD is a rare cerebrovascular occlusive disease of unknown etiology. It is commonly seen in Japan, although cases elsewhere have also been reported. Clinical manifestation is generally caused by cerebrovascular ischemia or hemorrhage, occasionally by epilepsy. Typically, no remarkable findings appear in the laboratory data.
Intra-arterial DSA, which is indispensable in achieving the diagnosis of MD, has revealed the following pathologic changes: bilateral stenosis or occlusion involving the supraclinoid portion of the ICA and the proximal portions at the ACA and MCA and development of parenchymal, leptomeningeal and transdural collateral vessels.
MR imaging shows infarctions and bleeding as consequences of cerebrovascular hypoperfusion. In some cases multiple, small, round or tortuous low-intensity areas arising in the basal ganglia are seen, which are thought to represent an abnormal network of parenchymal collaterals, the so-called Moyamoya vessels. Although the resolution of MR angiography is insufficient presently to visualize abnormal Moyamoya vessels, occlusive abnormalities in the ICA, ACA and MCA can be well detected as well as prominent collateral vessels arising from the PCA and the external carotid artery. Differential includes atherosclerotic occlusive disease, acute infantile hemiplegia and vasospasm.