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Background: Previous research has indicated that corpus callosum atrophy is associated with global cognitive decline in neurodegenerative diseases, but few studies have investigated specific cognitive functions.Objective: To investigate the role of regional corpus callosum atrophy in mental speed, attention and executive functions in subjects with age-related white matter hyperintensities (WMH).Methods: In the Leukoaraiosis and Disability Study, 567 subjects with age-related WMH were examined with a detailed neuropsychological assessment and quantitative magnetic resonance imaging. The relationships of the total corpus callosum area and its subregions with cognitive performance were analysed using multiple linear regression, controlling for volume of WMH and other confounding factors.Results: Atrophy of the total corpus callosum area was associated with poor performance in tests assessing speed of mental processing--namely, trail making A and Stroop test parts I and II. Anterior, but not posterior, corpus callosum atrophy was associated with deficits of attention and executive functions as reflected by the symbol digit modalities and digit cancellation tests, as well as by the subtraction scores in the trail making and Stroop tests. Furthermore, semantic verbal fluency was related to the total corpus callosum area and the isthmus subregion.Conclusions: Corpus callosum atrophy seems to contribute to cognitive decline independently of age, education, coexisting WMH and stroke. Anterior corpus callosum atrophy is related to the frontal-lobe-mediated executive functions and attention, whereas overall corpus callosum atrophy is associated with the slowing of processing speed. [ABSTRACT FROM AUTHOR]

Objectives: Subcortical ischaemic vascular disease (SIVD) is a subtype of vascular cognitive impairment characterised by extensive white matter lesions and multiple lacunar infarcts. Radiologically defined diagnostic criteria for SIVD have been introduced, but only a few studies have presented empirical data on its clinical and cognitive features. The aim of this study is to describe in detail the neuropsychological characteristics of patients with SIVD from a large well defined stroke cohort. Methods: A sample of 323 consecutive patients with ischaemic stroke, aged 55-85 years, was investigated using neuropsychological examination and magnetic resonance imaging (MRI). Patients fulfilling the MRI criteria of SIVD (n = 85) were compared to the other stroke patients (n = 238) and to normal control subjects (n = 38). Results: Cognitive performance of the SIVD group was inferior to that of the normal control group throughout all domains. As compared to the other stroke patients, the SIVD group performed significantly worse in tests measuring executive functions and delayed memory recall. Adjusting for depression had no effect on these results. Instead, after controlling for medial temporal lobe atrophy, the differences disappeared for delayed memory but remained significant for executive functions. Conclusion: Executive deficits are the most prominent cognitive characteristic associated with SIVD. Patients with SIVD also exhibit subtle deficits in delayed memory, which is explained in part by medial temporal lobe atrophy. Cognitive and mood changes seem to be parallel but independent processes related to SIVD. The results support the concept of SIVD as a separate clinical entity. [ABSTRACT FROM AUTHOR]

Objectives: Cerebral white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) are a recognised risk factor for post-stroke dementia. Their specific relations to cognitive impairment are still not well known. The purpose of this study was to explore how the severity and location of WMHs predict neuropsychological test performance in the context of other brain lesions in elderly stroke patients.Methods: In the Helsinki Stroke Aging Memory Study, 323 patients, aged from 55 to 85 years, completed a detailed neuropsychological test battery and MRI 3 months after an ischaemic stroke. The demographic and MRI predictors of cognition were studied with sequential linear regression analyses.Results: After age, education and total infarct volume were controlled for, the overall degree of WMHs predicted poor performance in tests of mental speed, executive functions, memory, and visuospatial functions, but not in those of short term memory storage or verbal conceptualisation. However, the contribution of separate white matter regions was relatively low. Only the lesions along the bodies of lateral ventricles were independently associated with speed and executive measures. Additionally, general cortical atrophy clearly predicted a wide range of cognitive deficits while infarct volume had less relevance. Further analyses revealed that executive functions act as a strong mediator between the relationship of WMHs to memory and visuospatial functions.Conclusions: The degree of WMHs is independently related to post-stroke cognitive decline. The most affected cognitive domains seem to be executive functions and speed of mental processing, which may lead to secondary deficits of memory and visuospatial functions. [ABSTRACT FROM AUTHOR]