Pathophysiology of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus.

This study was conducted to elucidate the pathologic conditions of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus (iNPH). Among 44 possible iNPH patients, 40 patients underwent shunt surgery based on diagnostic flow charts plotted by the Southern Tohoku method and were evaluated to be shunt-effective at the end of the first post-surgical month. The cerebral blood flow (CBF) was measured by N-isopropyl-((123)I)-P-iodo-amphetamine single photon emission computed tomography (mean, mCBF; cortical region, cCBF; thalamus-basal ganglia region, tbCBF on autoradiography [ARG] method) and the perfusion patterns of the cerebral cortex were measured based on three-dimensional stereotactic surface projection (3D-SSP) Z-score images, before and 1 month after the surgery in all 40 subjects.