Predicting Survival in Dementia With Lewy Bodies With Hippocampal Volumetry

Background: The clinical course of dementia with Lewy bodies patients is heterogeneous. The ability to more accurately prognosticate survival is important. Objective: The objective of this study was to investigate hippocampal volume as a predictor of survival in dementia with Lewy bodies patients. Methods: Survival analysis for time from onset of cognitive symptoms to death was carried out using Cox proportional hazards models. Given their age and total intracranial volume, patients were dichotomized into low/medium (0%-66.7%) and high (66. 7%-100%) hippocampal volume categories. The models using these categories to predict survival were adjusted for field strength, APOE ε4 status, and estimated onset age of cognitive problems. Results: We investigated 167 consecutive patients with dementia with Lewy bodies. The median age at MRI was 72 years (interquartile range 67-76), and 80% were male. The median time from estimated first cognitive symptom to death was 7.4 years (interquartile range:5.7-10.2). Lower hippocampal volumes were significantly associated with higher risk of death (hazard ratio 1.28; 95% confidence interval 1.04-1.58; P =.024). The predicted median survival for participants with onset of cognitive symptoms at age 68 was 10.63 years (95% confidence interval 8.66-14.54) for APOE ε4 negative, high hippocampal volume participants; 8.89 years (95% confidence interval 7.56-12.36) for APOE ε4 positive, high hippocampal volume participants; 8.10 years (95% confidence interval 7.34-11.08) for APOE ε4 negative, low/medium hippocampal volume participants; and 7.38 (95% confidence interval 6.74-9.29) years for APOE ε4 positive, low/medium hippocampal volume participants. Conclusions: Among patients with clinically diagnosed dementia with Lewy bodies, those with neuroimaging evidence of hippocampal atrophy have shorter survival times.