Differences in Survival between Patients with Dementia with Lewy Bodies and Patients with Alzheimer's Disease - Measured from a Fixed Cognitive Level.

Introduction: The aim of this study was to compare survival in patients with Alzheimer's disease (AD) and patients with dementia with Lewy bodies (DLB). Since anamnestic and retrospective information about disease duration are unreliable variables, we measured survival from a fixed cognitive level. Methods: Survival time was measured from the reported disease onset, from the time of diagnosis, from Mini-Mental State Examination (MMSE) 20 ± 1, and from MMSE 17 ± 1. Results: Survival time was significantly shorter in the DLB group compared to the AD group both from the time of diagnosis and from the cognitive levels of 20 and 17 on the MMSE. There was no difference in survival when measured from the reported disease onset. Discussion: Our findings indicate that DLB patients have a more malignant clinical course. Our method of investigating survival in a cognitively homogenous population may gain scientific power. Reliable methods to predict survival and the clinical course are of great value for patients, caregivers, doctors, and society