Brain Pathology for Memory Loss Like Pre-Alzheimer's
Postmortem brain samples show some similarities to early Alzheimer disease
THURSDAY, May 11 (HealthDay News) -- Patients with amnestic mild cognitive impairment (aMCI) have neuropathological changes that do not meet the criteria for a postmortem diagnosis of Alzheimer disease, but are beyond the neurofibrillary tangles seen with normal aging, according to a study in the May issue of the Archives of Neurology. The findings suggest that aMCI is an interim step on the way to the very early stages of Alzheimer disease.
Ronald C. Petersen, Ph.D., M.D., of the Mayo Clinic College of Medicine in Rochester, Minn., and colleagues compared brain samples from 15 subjects who had memory impairment but no signs of dementia at the time of death (aMCI group) to 28 healthy subjects and 23 patients with probable Alzheimer disease at the time of death.
All of the brains of the aMCI patients showed pathologic changes in the medial temporal lobe structures, which probably caused the patients' memory troubles. There were also a number of other pathologies, including argyrophilic grain disease, hippocampal sclerosis and vascular lesions.
"The observation that aMCI patients show 'early AD' pathologic change within the central nervous system may not come as a great surprise, but it has now been firmly established by this important study," Harry V. Vinters, M.D., of the UCLA Medical Center in Los Angeles, writes in an accompanying editorial.