Cerebral hemodynamics and oxygen metabolism in patients with moyamoya syndrome associated with atherosclerotic steno-occlusive arterial lesions.

BACKGROUND

Patients with major cerebral artery steno-occlusion and the formation of the moyamoya-like vessels associated with some other disorders have been distinguished from moyamoya disease and classified as moyamoya syndrome. The hemodynamic and metabolic backgrounds of the moyamoya syndrome associated with atherosclerosis have not yet been investigated. We aimed to elucidate the hemodynamic and metabolic characteristics associated with the development of basal moyamoya-like vessels in moyamoya syndrome with atherosclerosis.

METHODS

Twenty-one patients with chronic unilateral atherosclerotic steno-occlusive lesions of the internal carotid artery or middle cerebral artery (MCA) were enrolled in the study. Based on the angiographic findings, the patients were classified into 2 groups: the moyamoya syndrome group (n = 7) and the non-moyamoya-syndrome group (n = 14). We conducted angiographic evaluations of the extent of the development of basal moyamoya-like vessels in the moyamoya syndrome group. The cerebral blood flow, cerebral metabolic rate of oxygen, oxygen extraction fraction (OEF) and cerebral blood volume were measured using PET in the ipsilateral MCA area in the patients and in normal controls (n = 6).

RESULTS

The OEF in the ipsilateral MCA area, except in the basal ganglia, was significantly higher in the moyamoya syndrome group than in the non-moyamoya-syndrome group (p < 0.001). The extent of the development of basal moyamoya-like vessels was closely correlated with the elevation of the OEF (r > 0.999, p < 0.001).

CONCLUSION

The basal moyamoya-like vessels are evidence of misery perfusion in patients with unilateral chronic atherosclerotic steno-occlusive lesions of major cerebral artery trunks.