Posterior Ventricular Enlargement to Differentiate Dementia with Lewy Bodies from Alzheimer's Disease

Background: Enlargement of the lateral ventricle is observed in dementia associated with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Objective: The degree of anteroposterior ventricular enlargement and its correlation with clinical and neuropsychological features were investigated in DLB patients. Methods: Forty-eight patients with DLB, 76 with AD, and 45 subjects with normal cognition (NC) underwent structural brain MRI and detailed neuropsychological tests. Ventricular shape was compared among the groups by visual inspection. Posterior ventricle enlargement (PVE) was defined as the ratio of the distance between the temporal and occipital horns of the lateral ventricle to the distance between the temporal horn of the lateral ventricle and occipital pole of the brain. Results: After controlling for age, sex, and education, higher PVE was observed in the DLB group than in the AD group (68.5 ± 7.9 versus 62.8 ± 9.0, respectively; p=0.001) or the NC group (61.9 ± 9.9, p=0.002). However, higher PVE was not associated with poorer neuropsychological performance, nor was it associated with any clinical features in the DLB group after controlling for age, sex, and education. Conclusion: PVE occurs more often in DLB than in AD and NC. However, it is unclear how PVE is related to the clinical and neuropsychological features of DLB.