Patterns of cerebral hypoperfusion compared among demented and nondemented patients with stroke.

Abstract

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=ll) 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 hypoperfiision of the occipital cortex (p<0.05), apparently because of underlying leukoaraiosis and cortical disconnections. Perfusion of 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. (Stroke 1992^23:686-692) KEY WORDS • dementia • white matter • cerebral infarction

White Matter Changes and Poststroke Dementia

“…The location of white matter changes may also influence cognitive functions: amongst patients with lacunes, those who have dementia have more white matter lesions in the frontal lobes and their severity correlates with the cognitive decline [33,53]. Demented patients with multiple cerebral infarcts have lower perfusion rates of frontal and temporal cortical regions [54]: leukoaraiosis causing cortical disconnection is held responsible. It is wise to consider patients with white matter changes as prone to develop neuropsychological deficits, although several of them could probably remain free of any clinical abnormality [50].…”

Epidemiology of Vascular Dementia

“…The location of white matter changes might also influence cognitive functions: patients with lacunes and dementia have more white matter lesions in the frontal lobes and their severity correlates with the cognitive decline [130,131]. Lower perfusion rates of frontal and temporal cortical regions are seen in demented patients with multiple cerebral infarcts [132]: underlying white matter changes causing cortical disconnection were held responsible.…”

Some methodological issues in neuroradiological research in psychiatry

“…(1992), in a CT and PET study of patients with leukoaraiosis, reported that frontal leukoaraiosis contributed to dementia and was considered of ischemic origin, while parietal and occipital leukoaraiosis was considered to be due to Wallerian degeneration. Correlations of leukoaraiosis with cerebral hypoperfusion have been reported (De Cristofaro et al, 1990;Kawamura et al, 1991 a, b;Terayama et al, 1992;Yao etal., 1990). Scheltens etal.…”