Small vessel disease and hippocampal volume in Alzheimer's disease vs. controls

Conference Theme: Science and Aging: An Era of DiscoveryBackground: This study examined the prevalence and clinical impact of white matter hyperintensities (WMH), cerebral microbleeds (CMB) and medial temporal lobe atrophy (MTLA) in patients with Alzheimer's disease (AD). Methods: We analysed the data for 69 patients with AD and 36 age-matched cognitively normal controls recruited from Memory and Geriatric Medicine Clinics, Queen Mary Hospital. Controls had no history of dementia, stroke, Parkinson’s disease, head injury, seizures, AF, cancers within 5 years, end-stage organ failure, excessive alcohol or drug use, or psychiatric disease. 3T MRI brain images were retrospectively examined for the severity and location of WMH (Fazekas Score 0-3, >1 abnormal), CMB (Microbleed Anatomical Rating Scale 0-3, >0 abnormal) and MTLA (Scheltens Score 0-4, >1 abnormal). Results were adjusted for age, vascular risks including hypertension, stroke, TIA, hyperlipidaemia, and use of anti-thrombtic agents. Results: Mean (± s.d.) ages were similar for AD patients (76.6 ± 8.6 yrs) and controls (74.8 ± 6.6 yrs). Gender and history of diabetes, hypertension, hyperlipidaemia, and ischaemic heart disease were similar. AD patients were more likely to be dependent (p=.018), and live in nursing homes (p=.05). Controls were more likely to have atrial fibrillation (p=.007) and take antiplatelets (p=.02) or anticoagulants (p=.009). In the AD group, 13% of patients had a history of stroke or TIA, and the mean MMSE was 18.9 ± 4.9. Comparing AD vs. control groups, the prevalence of: a) abnormal periventricular WMH was 26% vs. 17% (p=.02); b) abnormal subcortical WMH was 40% vs. 72% (p=.002); c) CMB was 9% vs. 6% (p=.44); and d) abnormal MTLA was 62% vs. 33% (p=.004). Severity grades of MRI abnormalities were significantly different between AD and control groups for periventricular WMH (AD worse, p