Medial temporal lobe atrophy is independently associated with behavioural and psychological symptoms in Alzheimer's disease

Aim Evidence describing the contribution of cerebral white matter disease and medial temporal atrophy (MTA) to behavioural and psychological symptoms of dementia (BPSD) has been conflicting. The aim of this study was to assess the relationship of white matter hyperintensities (WMH) and MTA observed on magnetic resonance imaging with BPSD among patients with Alzheimer's disease. Methods In a cross-sectional study of a prospective cohort of patients attending a memory clinic, 46 patients with probable Alzheimer's disease (mean age: 72.38 +/- 7.05 years) were studied. Sociodemographic, cognitive, and BPSD data were collected. BPSD were assessed using the Neuropsychiatric Inventory. Magnetic resonance imaging, WMH, and MTA were rated using the Scheltens scales for the assessment of signal hyperintensities and atrophy of medial temporal lobes. For multivariate analysis, two binary logistic regression analyses were carried out, with presence or absence of each BPSD as the dependent variable and with WMH or MTA as the predictor variable. Results of the logistic regression were analyzed to see if the significance of the WMH or MTA score was maintained in a model that factored in other possible confounding variables identified in univariate analysis. Results The results of binary logistic regression analysis showed that in models that accounted for confounding variables, increased total MTA was significantly associated with apathy (odds ratio = 1.605, adjusted P = 0.042) and disinhibition (odds ratio = 0.607, adjusted P = 0.042). WMH measures did not significantly predict any BPSD item. Conclusions These findings indicate that MTA potentially contributes to the aetiology of BPSD, and they provide evidence to support the hypothesis that Alzheimer's disease pathology itself can contribute to BPSD.