Semantic memory is impaired in both dementia with Lewy bodies anddementia of Alzheimers type: a comparative neuropsychological studyand literature review

摘要

OBJECTIVE—To test the hypothesis that semantic impairment is present in both patients with dementia with Lewy bodies (DLB) and those with dementia of Alzheimer's type (DAT).
METHODS—A comprehensive battery of neuropsychological tasks designed to assess semantic memory, visuoperceptual function, verbal fluency, and recognition memory was given to groups of patients with DLB (n=10), DAT (n=10) matched pairwise for age and mini mental state examination (MMSE), and age matched normal controls (n=15).
RESULTS—Both DLB and DAT groups exhibited impaired performance across the range of tasks designed to assess semantic memory. Whereas patients with DAT showed equivalent comprehension of written words and picture stimuli, patients with DLB demonstrated more severe semantic deficits for pictures than words. As in previous studies, patients with DLB but not those with DAT were found to have impaired visuoperceptual functioning. Letter and category fluency were equally reduced for the patients with DLB whereas performance on letter fluency was significantly better in the DATgroup. Recognition memory for faces and words was impaired in both groups.
CONCLUSIONS—Semanticimpairment is not limited to patients with DAT. Patients with DLBexhibit particular problems when required to access meaning frompictures that is most likely to arise from a combination of semanticand visuoperceptual impairments.