頭蓋内圧波を利用した収縮期脳血流の測定

Abstract

As an index for estimation of cerebral vasospasm in ruptured aneurysms, systolic cerebral blood inflow rate (SCBIR) has been derived. The relationship between SCBIR and cortical CBF measured by a thermo-gradient flow meter was analyzed in 4 patients with SAH, and the relationship between them was statistically significant (CBF=0.04×SCBIR+33.7, r=0.7, p<0.05, n=10). SCBIR was reduced in all patients who seemed to have vasospasm as estimated by a reduction in CBF. On day 3, a moderate reduction in SCBIR was found in one patient even when no cortical CBF reduction was present. Shortly thereafter, however, cortical CBF started to decrease. Subsequently, SCBIR increased concomitant with the increase in cortical CBF in all surviving patients except one who eventually died one month after the onset. The total reduction in cortical CBF in the vasospasm period was-29.2±6.3% mean sd), while SCBIR at this time was-52.8±7.2% (mean±sd)(p<0.05).In conclusion: (1) SCBIR can be calculated by the ICP pulse wave and intracranial pressure volume relationship (PVI). (2) Generally, SCBIR was correlated with cortical CBF in the early stage of vasospasm and its recovery. However, the statistical test indicated that SCBIR was more sensitive than cortical CBF to the change in cerebral hemodynamics, especially, in the early phase of vasospasm. Thus, there is a possibility of early detection of cerebral vasospasm by analyzing the ICP pulse wave and pressure volume relationship.