Comorbidity in dementia: an autopsy study.

Context There is a paucity of accurate postmortem data pertinent to comorbid medical conditions in patients with dementia, including Alzheimer disease. Objectives The purposes of this study were (a) to examine general autopsy findings in patients with a dementia syndrome and (b) to establish patterns of central nervous system comorbidity in these patients. Design Review of autopsy reports and selected case material from 202 demented patients who had autopsies during a 17-year period (1984-2000) and from 52 demented patients who had general autopsies during a 6-year period (1995-2000). Setting Large academic medical center performing approximately 200 autopsies per year. Results Among the 52 patients who underwent complete autopsy, the most common cause of death was bronchopneumonia, which was found in 24 cases (46.1%). Other respiratory problems included emphysema, found in 19 (36.5%) of 52 patients, and pulmonary thromboembolism, found in 9 (17.3%) of 52 patients. In 6 cases, pulmonary thromboembolism was the proximate cause of death. Twenty-one (40.3%) of the 52 patients had evidence of a myocardial infarct (varying ages) and 38 (73.1%) had atherosclerotic cardiovascular disease, 27 of a moderate to severe degree. Four clinically unsuspected malignancies were found: 1 each of glioblastoma multiforme, diffusely infiltrative central nervous system lymphoma, pancreatic adenocarcinoma, and adenocarcinoma of the lung. One patient with frontotemporal dementia and amyotrophic lateral sclerosis died of severe meningoencephalitis/ventriculitis, probably secondary to seeding of the central nervous system by an infected cardiac valve. Of the 202 demented patients who underwent brain-only autopsies, the following types of dementia were found: 129 (63.8%) cases showed changes of severe Alzheimer disease, 21 (10.4%) showed combined neuropathologic abnormalities (Alzheimer disease plus another type of lesion, such as significant ischemic infarcts or diffuse Lewy body disease), 12 (5.9%) cases of relatively pure ischemic vascular dementia, 13 (6.4%) cases of diffuse Lewy body disease, and 8 (4.0%) cases of frontotemporal dementia. The remaining 19 (9.4%) patients showed miscellaneous neuropathologic diagnoses, including normal pressure hydrocephalus and progressive supranuclear palsy. Among the demented patients, 92 (45.5%) had cerebral atherosclerosis, which was moderate to severe in 65 patients (32.2%). Conclusions Some of the conditions found at autopsy, had they been known antemortem, would likely have affected clinical management of the patients. Autopsy findings may be used as a quality-of-care measure in patients who have been hospitalized in chronic care facilities for a neurodegenerative disorder.