A prospective study of dementia with Lewy bodies

Background: little is known about the longitudinal course of dementia with Lewy bodies (DLB) and how this differs from Alzheimer's disease (AD). Method: standardized baseline and annual assessments of cognitive and non-cognitive symptoms are reported in a cohort of 72 patients with DLB or AD. AD was diagnosed using the NINCDS ADRDA criteria and DLB was diagnosed with the criteria of McKeith et al. Cognitive assessment was undertaken using the MMSE schedule and operationalized definitions were used to diagnose non-cognitive symptoms. Results: 42 patients with DLB and 30 patients with AD were assessed. Of the 19 on whom post mortem examinations have been performed, 18 (95%) have had the clinical diagnosis confirmed. DLB patients were significantly more likely to experience visual hallucinations, disturbances of consciousness and parkinsonism at both baseline and at annual assessments. Of DLB patients exposed to neuroleptics, 33% developed sensitivity reactions. The magnitude and pattern of cognitive decline was similar in both groups. Conclusion: the importance of the core features highlighted in the newly proposed consensus DLB criteria is supported. These features appear to be stable over time.