Submitted by Dr Arthur CW Lau on 13 May 2010, ICU, Pamela Youde Nethersole Eastern Hospital, Hong Kong
A 52-year old female was admitted for extensive intraventricular haemorrhage. CT angiogram of the Circle of Willis was done (shown below). What is the diagnosis?
Figure. CT angiogram, click image to enlarge.
The original CT brain shows extensive intraventricular haemorrhage are seen involving the lateral, third and fourth ventricles.
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The full CT angiogram shows:
The major intracranial arteries, especially the anterior cerebral arteries and middle cerebral arteries are narrowed with multiple stenotic segments. Extensive tortuous "net-like" vessels are seen in bilateral anterior and posterior circulation, most prominent over the basal cisterns region. These are compatible with collaterals formation. A small roundish pool of contrast measuring about 2.5×3.0x2.5mm (APXTSXLS) in seen in the right thalamic region, suspicious of an aneurysm, possibly arising from a lenticulostriate branch vessel. Another small roundish pool of contrast measuring about 3mm in size is seen in the low left paramedial frontal region, may represent another aneurysm, possibly arising from a left anterior cerebral artery (ACA) branch.
3D-reconstruction:
Two drainage catheters are seen, as well as stenotic arteries and collaterals .
Dx: As narrowed major intracranial arteries with stenotic segments and extensive bilateral collaterals vessels formation are seen, the overall picture is compatible with Moyamoya disease.
Discussion
Moyamoya disease was first described in 1957 by Japanese surgeons Takeuchi and Shimizu. The term "moyamoya" means haze, mist, cloud, smoke or vapor. Moya is もや in Japanese, in Kanji (漢字）, it is 靄, i.e. 霧靄 in Chinese, which means haze, mist or fog. It is used to describe the angiographic appearance of the smoke-like abnormal vascular collaterals arising as a result of the stenosis. It occurs more in Orientals than in Caucasians. This condition may cause both cerebral ischemia and hemorrhage. Transient ischemic attacks may occur, and it is said that attacks are easier to occur after crying, blowing on hot noodles or playing wind instruments because of hyperventilation-associated cerebral vasoconstriction. There is no medical therapy. Bypass surgeries (direct or indirect) may help.
Reference
Fukui M, Kono S, et al. Moyamoya disease. Neuropathology 2000; 20, S61 – 64 (link here)