MRI-defined subcortical ischemic vascular disease : baseline clinical and neuropsychological findings

Background: Subcortical ischemic vascular disease (SIVD) is a common, but often overlooked cause of vascular cognitive impairment. Diagnostic research criteria for SIVD are based on magnetic resonance imaging (MRI) findings including substantial white matter lesions (WML) and multiple lacunar infarcts. Empirical studies validating these imaging criteria are still few. The purpose of the study was to describe the clinical and cognitive characteristics of the MRI-defined SIVD in a mixed sample of functionally independent elderly subjects with WML. Methods: The subjects of the Leukoaraiosis and Disability (LADIS) study, aged 65-84 years, underwent comprehensive clinical and neuropsychological examinations, and brain MRI at the baseline assessment. The subjects meeting the SIVD imaging criteria (n = 89) were compared to the other subjects of the sample (n = 524). Results: SIVD was associated with lower education, hypertension and, independently, with obesity. The subjects with SIVD had more often motor impairment, a history of falls, and subtle impairment in activities of daily living, but they did not differ for depressive symptoms. SIVD subjects performed significantly inferiorly in tests of global cognitive function, psychomotor speed, attention and executive functions, verbal fluency, and working memory. Conclusion: In this population of nondisabled older adults with WML, SIVD was related to specific clinical and functional characteristics. Neuropsychological features included psychomotor slowing as well as deficits in attention and executive functions.