Background and Purpose-Cerebral microangiopathy, indicated on MRI by lacunar infarctions (LI) and deep white matter lesions (DWML), is said to lead to vascular dementia. Methods-Fifty-seven patients with proven cerebral microangiopathy were assessed for changes in regional cerebral blood flow (rCBF) and glucose metabolism (rMRGlu) and compared with 19 age-matched controls.

Glucose metabolism is reduced more than perfusion in the septal compared with LV lateral wall in patients with DCM and LBBB. Cardiac resynchronization therapy restores homogeneous myocardial glucose metabolism with less influence on perfusion.

We used single-photon emission computed tomography to measure cerebral blood flow, cerebral blood volume, and cerebral perfusion reserve and transcranial Doppler sonography with CO, stimulation to assess hemispheric vasomotor reactivity in 37 patients and in normal controls. Computed tomography and magnetic resonance imaging were performed to differentiate morphologically low-flow infarcts (n=17) from territorial infarcts (n=20). In patients with either type of infarct, blood flow was decreased and blood volume was increased in the infarcted areas compared with the same areas in the controls. Perfusion reserve and vasomotor reactivity were significantly reduced in patients with territorial infarcts and carotid artery occlusions (n=12) and even more reduced in patients with low-flow infarcts (p< 0.001). Both parameters were normal in patients with cardiac embolic territorial infarcts (n=8). In patients with territorial infarcts, blood flow and perfusion reserve changes were restricted to the infarcted areas, whereas in patients with low-flow infarcts, regions of decreased perfusion reserve considerably exceeded the area of the infarct Low-flow infarcts are related to the hemodynamic effects of severe extracranial carotid artery disease. (Stroke 1991^2:1117-1123)