Cerebral ischemia due to compression of the brain by ossified and hypertrophied muscle used for encephalomyosynangiosis in childhood moyamoya disease.

Background: Encephalomyosynangiosis is one of the indirect method in which ischemic brain surface is covered by temporal muscle for the treatment of moyamoya disease.

Case Descriptions: A 14-year-old girl who had been treated with bilateral STA-MCA anastomosis and EMS in 1999 was admitted on January 5, 2005. She showed transient incomplete palsy on the left side of the face and the ipsilateral upper extremity. On the day of admission, MRIs/MRA and 3-dimensional regional CBF measurement using stable xenon and CT scanning were conducted after performance of plain CT scanning. The MRI and CT studies showed that ossified and hypertrophied temporal muscle used for EMS to the right MCA territory compressed the brain just under the muscle. MRA demonstrated well-developed collaterals to the territories of the bilateral MCAs via the previously performed anastomosis. The CBF studies disclosed a low CBF value just under ossified and hypertrophied muscle used for EMS on the right side. She showed same transient ischemic attacks repetitively after January 5, 2005.

Conclusions: The repetitive attacks with the transient motor palsy on her left side was thought to be caused by direct compression of the brain by the ossified and hypertrophied muscle used for EMS and decrease in CBF just under it, and its removal was thought to be the treatment of choices. However, the patient and her parents refused the surgical procedure, and she is treated conservatively at present.