Mild Cognitive Problems Lead to Various Types of Dementia
Post-mortem brain analyses show patients can progress to neuropathology other than Alzheimer's
FRIDAY, May 12 (HealthDay News) -- Patients with mild cognitive impairment sometimes progress to types of dementia other than Alzheimer disease, according to a study in the May issue of the Archives of Neurology.
Gregory A. Jicha, M.D., Ph.D., from the Mayo Clinic College of Medicine in Rochester, Minn., and colleagues performed post-mortem analyses on the brains of 34 subjects with a mean age of 89 years at death who had been part of a community-based study. The subjects had been diagnosed with amnestic mild cognitive impairment and had gone on to develop clinical dementia.
The brain analyses revealed that 24 of the subjects (71 percent) had developed Alzheimer disease. However, 10 patients (29 percent) had developed primary pathologic abnormalities unrelated to Alzheimer disease. These other abnormalities included Lewy body disease, hippocampal sclerosis, nonspecific tauopathy and others. Demographic features and the level of cognitive impairment both appeared to be unrelated to which patients developed Alzheimer disease and which developed other kinds of dementia.
"Complex neuropathologic findings including two or more distinct pathologic entities contributing to dementia may be common in community-based cohorts," the authors conclude.
In an accompanying editorial, Lawrence A. Hansen, M.D., of the University of California San Diego School of Medicine, writes that the study's results are "a sobering reminder that even with a thoroughly documented clinical course progressing from mild cognitive impairment to dementia, a final clinical diagnosis of Alzheimer disease may be wrong in a significant minority of patients."