Histopathological studies on spontaneous vault Moyamoya and revascularized collaterals formed by encephalomyosynangiosis

Abstract Two topics concerning the leptomeningeal vessels are discussed. The first portion indirectly proves that angiographic `vault Moyamoya' consists of dilated preexisted vessels rather than newly-formed vessels, using morphometric analysis. The second portion presents a 67 year old autopsied case with Moyamoya disease who underwent encephalomyosynangiosis (EMS). Collateral vessels formed by EMS are histopathologically identified.