Brief cognitive assessment for patients with cerebral small vessel disease

Background: Cerebral small vessel disease is a common cause of cognitive impairment and vascular dementia. The cognitive deficit differs from that in Alzheimer's disease, with greater executive/ attentional dysfunction and relatively intact episodic memory. Objective: To develop brief assessment tools that are better adapted to the neuropsychological profile of cerebral small vessel disease. Methods: 32 subjects with ischaemic leukoaraiosis ( history of lacunar stroke and leukoaraiosis on MRI), aged 50 to 84 years, and 17 age and education matched controls had a brief executive assessment, which took 20 minutes to administer, and a wide range of additional tests. The ability of the brief executive assessment to discriminate between groups - both individually and in combination - was evaluated and compared with that of the whole battery. Results: The brief executive assessment provided good sensitivity and specificity for identifying subjects with ischaemic leukoaraiosis ( sensitivity 88%, specificity 88%, using the optimal combination of scores). The best individual tests were trail making and digit symbol, which were both far more sensitive than the mini-mental state examination (MMSE). The ability to discriminate between groups was maintained in subjects with MMSE >27 and across the whole age range. The brief executive assessment performed well compared with the whole battery, with additional tests accounting for only a further 12% of between-group variance. Conclusions: The brief executive assessment was sensitive to deficits found in ischaemic leukoaraiosis and discriminated them from the cognitive effects of healthy aging. The assessment has potential for bedside use and as a cognitive end point for clinical trials.