PATTERNS OF CEREBRAL HYPOPERFUSION COMPARED AMONG DEMENTED AND NONDEMENTED PATIENTS WITH STROKE

Background and Purpose: No reports are available that compare local cerebral perfusion among groups of patients suffering from multiple cerebral infarctions with and without cognitive impairments. The present study was designed to correlate changes in regional cerebral perfusion that may lead to dementia among patients with multiple cerebral infarctions by comparing measurements of local cerebral blood flow. Methods: local perfusion was measured using xenon-contrasted computed tomographic scanning among two groups of patients who had suffered from multiple cerebral infarctions: Group D (n = 12) were demented and had severe cognitive impairments, and group I (n = 11) were cognitively intact. Results were compared with similar measurements among neurologically and cognitively normal, age-matched volunteers (group N, n = 16). Results: Mean local perfusion values were reduced among both groups with cerebral infarctions but to a more marked degree in group D (p < 0.05). Perfusion of cerebral white matter was diffusely and severely reduced in group D (p < 0.05) but was mildly reduced only in frontal and capsular white matter in group I (p < 0.05). Perfusion of cerebral cortex was reduced in frontal (p < 0.01) and temporal (p < 0.01) regions among both groups but to a significantly greater degree in group D subjects (frontal, p < 0.05; temporal, p < 0.01), who also showed hypoperfusion of the occipital cortex (p < 0.05), apparently because of underlying leukoaraiosis and cortical disconnections. Perfusion ot the basal ganglia was reduced to the same degree among both groups of stroke patients (p < 0.01). Conclusions: Leukoaraiosis with white matter hypoperfusion appears to be an important determinant for cognitive impairments among patients with multiple cerebral infarctions.