| Dementia is a devastatingly serious problem in industrialized countries, such as Japan and the United States. The most prominent dementia subtypes: Alzheimer's disease (AD) and vascular dementia (VaD) show a different pattern in these two countries. Most research studies on cognitive aspects of dementia have been conducted in western countries, but not in Japan, because of its short history of neuropsychology. To date, there has been only one Japanese study, and a criticism of this study is that it used tests that were insufficient and not culturally appropriate. It is necessary to explore what neuropsychological tests are sensitive and appropriate for a Japanese population in order to lead to more accurate diagnosis treatment strategies.;The present study aimed to identify valid neuropsychological tests for Japanese elders and to examine test profiles of AD and VaD in comparison to what is known in western neuropsychology. Five cognitive domains: executive control, information processing speed, visuospatial/construction, language, and learning and memory were evaluated. Seventy Japanese elders (30 healthy controls, 20 AD patients, and 20 VaD patients) participated in this study.;The present study indicated the usability of verbal learning and spatial memory tests, visuospatial/constructional tests, and a semantic fluency test for differentiating Japanese AD and VaD. These results suggest that Japanese AD patients showed a similar neuropsychological profile as that found in western studies (i.e. impairment in memory, visuospatial, and semantic knowledge). Japanese VaD patients, however, demonstrated less severity in executive control and motor slowness as compared to American VaD patients. It is possible that Japanese VaD patients have fewer white matter changes in the frontal lobe, and/or cultural factors, especially intensive training in pictorial written language (Kanji), might impact VaD patients' cognition.;The present study was the first study to evaluate the usability of a culturally appropriate neuropsychological test battery for distinguishing between Japanese AD and VaD. A new Japanese Verbal Learning test, the PVLT-J was developed particularly for the study. This study has immediate clinical utility for use in dementia diagnosis in Japan, and it is hoped that it will spur more research in comparative brain-behavior processing across cultures. |
