Comparative Study of Risk Factors and Cognitive Profile of Small- and Large-Vessel Vascular Dementia - A Clinic Based Study

Background: Vascular dementia (VaD) is a clinically heterogeneous entity. There is a dearth of studies for comparison of the cognitive profile of cerebral small-vessel disease (SVD) with large-vessel disease. Objective: We planned to evaluate and compare the cognitive profile of SVD and large-vessel VaD and evaluate various risk factors associated with them. Materials and Methods: Patients of VaD were recruited after excluding mixed and ambiguous cases. Patients were classified into SVD and large-vessel VaD and analyzed for their clinic-epidemiological and cognitive profiles. Results: Among 76 patients, 48 (62.5%) have SVD and 28 (37.5%) have large-vessel disease. Hypertension (93.4%) was the commonest risk factor, followed by smoking (34.21%), hyperlipidemia (26.31%), and diabetes mellitus (DM, 22.36%). Hypertension (P < 0.05) and DM were common in SVD, whereas smoking, hyperlipidaemia, and cardiac diseases were common in large-vessel disease. Attention (77.1% vs 25%), executive function (68.8% vs 28.6%), and calculation (58.3% vs 32.1%) were significantly more impaired in SVD compared to large-vessel disease, whereas visuoperceptual (21.4% vs 6.3%), praxis (28.6% vs 4.2%), and gnosis (14.3% vs 2.1%) were significantly more impaired in large-vessel disease than in SVD. Disruption of frontal-subcortical connection was responsible for the cognitive profile in SVD, but in large-vessel disease, it resulted from the cumulative loss of function from different lesions. Conclusions: Despite having common vascular risk factors, few are more common in SVD than in large-vessel disease. The different clinical and cognitive profile is due to the diverse anatomical lesions in these two subclasses of VaD.