Kanji and Kana agraphia in mild cognitive impairment and dementia: A trans-cultural comparison of elderly Japanese subjects living in Japan and Brazil

要旨

This study verifies the environmental effects on agraphia in mild cognitive impairment and dementia. We compared elderly Japanese subjects living in Japan and Brazil. METHODS: We retrospectively analyzed the database of the Prevalence Study 1998 in Tajiri (n=497, Miyagi, Japan) and the Prevalence Study 1997 of elderly Japanese immigrants living in Brazil (n=166, migrated from Japan and living in the São Paulo Metropolitan Area). In three Clinical Dementia Rating (CDR) groups, i.e., CDR 0 (healthy), CDR 0.5 (questionable dementia), and CDR 1+ (dementia) , the Mini-Mental State Examination (MMSE) item of spontaneous writing and the Cognitive Abilities Screening Instrument (CASI) domain of dictation were analyzed with regard to the number of Kanji and Kana characters. Formal errors in characters and pragmatic errors were also analyzed. RESULTS: The immigrants in Brazil wrote similar numbers of Kanji or Kana characters compared to the residents of Japan. In spontaneous writing, the formal Kanji errors were greater in the CDR 1+ group of immigrants. In writing from dictation, all the immigrant CDR groups made more formal errors in Kana than the Japan residents. No significant differences in pragmatic errors were detected between the two groups. CONCLUSIONS: Subjects living in Japan use Kanji frequently, and thus the form of written characters was simplified, which might be assessed as mild formal errors. In immigrants, the deterioration in Kanji and Kana writing was partly due to decreased daily usage of the characters. Lower levels of education of immigrants might also be related to the number of Kanji errors.

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