Cognitive variations among vascular dementia subtypes caused by small-, large-, or mixed-vessel disease

INTRODUCTION: Vascular dementia (VaD) is a heterogeneous disease that can vary in clinical presentation and cognitive profile. The cognitive profiles of different VaD subtypes depend on the anatomical distribution of the vascular insults that have been documented. MATERIAL AND METHODS: We reviewed demographic, cognitive, and imaging data in 402 patients who were clinically diagnosed with VaD between January 2002 and June 2012 at the First Affiliated Hospital of Gan Nan Medical College in Ganzhou, China. RESULTS: Based on magnetic resonance imaging (MRI) results, patients were classified as having large- (24.1%), small- (70.4%), or mixed-vessel VaD (5.5%). Hypertension was the most prevalent risk factor (81%), followed by smoking (37%), hyperlipidemia (35%), and diabetes (27%). Hyperlipidemia, cardiac risk factors (history of cardiovascular disease, heart valve disorder) and carotid stenosis were more frequent in patients with large-vessel disease compared to those with small-vessel or mixed-vessel disease (p < 0.001). A median of 4 (maximum 11) cognitive domains were impaired in each VaD patient. After memory dysfunction, executive defects were the most prevalent (68.9%), and neurobehavioral dysfunction was the most rare (13.2%). Patients with small-vessel VaD showed more executive dysfunction than patients with large-vessel and mixed-vessel VaD (p < 0.05), whereas patients with large-vessel VaD had a higher prevalence of visuospatial or language dysfunction (p < 0.05). CONCLUSIONS: The results indicate that specific subtypes and underlying vascular mechanisms will help predict clinical courses and produce more focused treatment and prevention of VaD.