髄液中NO代謝物はもやもや病側副血行発達の指標となりうるか

Abstract

Moyamoya disease is a unique disease of unknown etiology typically characterized by progressive occlusion of both internal carotid arteries accompanied by an abnormal collateral circulation referred to as moyamoya vessels. To compensate for lack of blood flow in the frontal region, the collateral circulation develops from delicate basal networks and the vertebrobasilar system, and often is demonstrated by angiography, MRI or MRA. To investigate whether nitric oxide (NO) contributes to formation of abnormal collateral circulation in patients with moyamoya disease, we measured concentrations of NO metabolites in cerebrospinal fluid (CSF) obtained during treatment of this disease with bypass surgery.CSF samples were obtained from the subarachnoid space of the sylvian fissure during combined bypass surgery for moyamoya disease and kept frozen untill NO metabolites, nitrate and nitrite were measured using a Griess method.Compared with control specimens of CSF obtained from 16 patients with hemifacial spasm (n=8), trigeminal neuralgia (n=2), nonruptured aneurysm (n=5), or tremor (n=1), concentrations of NO metabolites in the CSF of 23 patients with moyamoya disease were significantly higher (18.6+1.1 vs. 11.0+1.0μM). NO metabolite concentrations (21.6+2.3μM) in CSF obtained during initial surgery in 7 resampled patients decreased to 16.9+1.5 μM in CSF obtained during a second, contralateral precedure. Angiographically early moyamoya disease tended to show lower concentrations of NO metabolites than cases of with greater development of moyamoya vessels.NO concentrations in CSF were chronically elevated in moyamoya disease, probably reflecting development of collateral circulation. Vascular bypass surgery can reduce NO metabolites together with abnormal collateral circulation.