To the Editor.
—The important study by Stern and colleagues1 provides useful data on which clinicians can base prognostic estimates for persons with Alzheimer disease. However, their finding that extrapyramidal signs and psychotic features at initial assessment predicted earlier nursing home placement and death suggests the possibility that some of these cases suffered from Lewy body dementia rather than Alzheimer disease. Early hallucinations, delusions, and extrapyramidal symptoms are now included in the diagnostic criteria for Lewy body dementia.2,3 While autopsy confirmation of diagnosis is available for only half of the subjects, it would be useful to test the hypothesis that those with the most rapid progression and shortest time to nursing home placement had either Lewy bodies coexisting with neuritic plaques and neurofibrillary tangles or pure Lewy body dementia based on neuropathology.
Rabins PV. Predicting Progression of Alzheimer Disease. JAMA. 1997;277(24):1933-1934. doi:10.1001/jama.1997.03540480033030