Callosal atrophy in patients with lacunar infarction and extensive leukoaraiosis. An indicator of cognitive impairment.

Abstract

It is unclear why only some patients with lacunar infarction and radiological evidence of diffuse white matter abnormalities have dementia. The purpose of this study is to investigate the value of callosal atrophy as an indicator of cognitive impairment. We used magnetic resonance imaging to evaluate 11 right-handed male patients with lacunar infarction and extensive white matter hypodensities on computed tomography (8 with dementia and 3 without dementia). The midsagittal corpus callosum area on T1-weighted images was compared with the IQ determined by the Wechsler Adult Intelligence Scale. The relation between these parameters and cerebral oxygen metabolism measured with positron emission tomography was also evaluated in the 8 patients with dementia. All patients showed diffuse high-intensity areas in the bilateral hemispheric white matter on T2-weighted images. Compared with 19 age- and sex-matched right-handed normal control subjects, the patients had a significantly smaller callosal area. The severity of callosal atrophy, which varied from mild to severe, was significantly related to the total IQ. In the 8 demented patients, the total callosal area was significantly correlated with the mean level of oxygen metabolism in the cerebral white matter. In patients with lacunar infarction and diffuse white matter abnormalities, the presence of callosal atrophy may indicate cognitive impairment. Callosal atrophy may reflect the severity and extent of white matter damage associated with a decrease in oxygen metabolism, which may determine the severity of intellectual decline.

White Matter Changes Contribute to Corpus Callosum Atrophy in the Elderly: The LADIS Study

“…Nevertheless, our results are in accordance with the studies of Yamauchi et al (1994 and1995). 20,33 They reported that callosal atrophy occurs in patients with cerebrovascular disease.…”

“…20,33 They reported that callosal atrophy occurs in patients with cerebrovascular disease. In contrast, Pantel et al (1998) 34 failed to demonstrate significant differences between vascular dementia and controls with respect to global and regional callosal size.…”

“…18 The mechanism for CC atrophy is poorly understood, but CC atrophy may reflect pathologic changes in subcortical white matter, as reported in patients with multiple sclerosis 19 and vascular dementia. 20 In healthy elderly subjects, CC atrophy may result from axonal disruption due to white matter damage.…”

Diffuse Tract Damage in the Hemispheric Deep White Matter May Correlate with Global Cognitive Impairment and Callosal Atrophy in Patients with Extensive Leukoaraiosis

“…6 However, patients with extensive WMLs show a variable severity of global cognitive impairment, with some patients showing vascular dementia, whereas others have almost normal cognitive function despite extensive WMLs. [7][8][9] A longitudinal study demonstrated that further global cognitive deterioration occurs with time in patients with extensive WMLs whose cognitive impairment was mild initially. 6 Therefore, understanding the pathophysiology that may cause a variable severity of cognitive impairment in patients with similar extensive WMLs may lead to the development of optimal therapeutic interventions preventing vascular dementia.…”

“…8,9 The corpus callosum consists of interhemispheric corticocortical connecting fibers, and most of the fibers traverse the HDWM while approaching the contralateral hemisphere. 9 In extensive leukoaraiosis, ischemic insult to the HDWM may affect all of the component fiber tracts, irrespective of their fiber directions.…”