Ultrastructural studies of cerebral arteries and collateral vessels in moyamoya disease.

Abstract

SUMMARY Moyamoya disease was originally defined as a characteristic syndrome of recurrent headaches, occlusion of the distal internal carotid arteries and the foggy (moyamoya) clusters of collateral vessels at the base of the brain as demonstrated by cerebral angiography. The etiology is unknown and pathobiology is poorly understood. We examined the intracranial arteries in 3 patients to demonstrate characteristic changes and to obtain a better understanding of the basis mechanisms of the disease. Controls were obtained from 3 normotensive patients who died as a result of cancer. Occluded internal carotid arteries were characterized by severe thickening of the intima with a dense luminal array of smooth muscle cells, a deeper less cellular zone, pronounced tortuosity of the internal elastica and thinning of the media. Collateral vessels were arterial in structure and were affected by similar prollferative changes in the intima, thinning of the media, and contorted internal elastica. Stainable lipids were not part of the typical components. Severe contortion of the internal elastica, medial damage and intimal proliferation may result from recurrent and sustained spasticity of the cerebral arteries. The distal lenticulostrlate arteries showed severe medial damage similar to what is termed as a moth-eaten change in hypertensive patients dying of massive cerebral hemorrhage. Stroke Vol 15, No 4, 1984ARTERIAL CHANGES IN MOYAMOYA DIS-EASE, as shown by angiography of the distal internal carotid artery, reveal lipid-free fibromuscular thickening and the development of presumably newly formed collateral vessels at the base of the brain.' These collaterals are so characteristic that the term moyamoya vessels has been applied to them. 2 Occlusion of the internal carotid artery caused by atherosclerosis, is not accompanied by the appearance of collateral vessels and is characterized by the presence of stainable lipids.The term moyamoya disease was coined for the "foggy" collateral channels demonstrable by cerebral angiography.2 The disease is relatively uncommon and shows no relationship to systemic hypertension. This disease was first reported in, but it is not confined to, the Japanese. The condition is frequently familial, and may occur in infants and children as well as in adults.1 4 The pathogenesis is unknown and the possibilities include genetic factors.3 3 Intracerebral and subarachnoid hemorrhages are frequent complications. 6 Moyamoya disease of the juvenile type often manifests itself by transient ischemic attacks, and the adult type usually presents as a massive intracerebral hemorrhage.* Thus moyamoya disease provides an interesting model for studies of arterial disease and its complications. The histologic features and morphometry of arterial changes in 22 patients with moyamoya disease have been reported by others. 7The present study was undertaken to characterize ultrastructural changes of the circle of Willis and collateral moyamoya vessels, and to obtain a better un- derstanding of the basic mechanisms of ...

Altered cellular responses to serum mitogens, including platelet‐derived growth factor, in cultured smooth muscle cells derived from arteries of patients with moyamoya disease

“…Stainable lipids are only occasionally noted in the intima of moyamoya disease (Takebayashi et al, 1984). These findings may support different mechanisms of development of intimal thickening in moyamoya disease and atherosclerosis.…”

Moyamoya disease mimicking a spontaneous internal carotid artery dissection on Doppler ultrasound

“…Other processes, such as tuberculous meningitis [4] and radiotherapy [5], have been implicated in the formation of moyamoya vessels around the base of the brain by causing progressive occlusion of the terminal ICA. Pathological specimens of the vessels affected by moyamoya disease demonstrate lipid-free fibrocellular thickening of the vascular intima [6]. Enhanced angiogenesis accompanies moyamoya disease and basic fibroblast growth factor, a potent angiogenic factor, is increased in tissues of patients with moyamoya disease [7,8].…”

Mechanisms Underlying Arterial Fragility and the Complications of Atherosclerosis

“…granulovesicular degeneration of SMCs, and secondary intimal proliferation with both occlusive and aneurysmal changes as in lipohyalinosis. Vascular fragility is further indicated by the prevalence of aneurysms and hemorrhag ic events [59][60][61], Aneurysms are permanent localized dilatations of blood vessels consequent upon mural weakness as in post stenotic dilatation which is readily produced in experi mental animals and rubber tubing. Strong evidence indi cates dilatation is due to vibrational fatigue of the artery or tubing.…”