DYSGRAPHIA IN MILD DEMENTIA OF ALZHEIMERS TYPE

We assessed writing abilities in a cohort of 31 patients with a diagno sis of DAT (in two subgroups, with minimal [MMSE 24-28] and mild [MMSE 16-23] levels of dementia), and 10 matched controls. Central aspects of writing were assessed by both written and oral spelling to dictatio n of 72 single words varying in frequency (high or low) and predictabi lity of sound-to-spelling correspondences (predictable, unpredictable and irregular). All subjects achieved better scores on high, as compar ed to low, frequency words. The performance of both patient groups was significantly affected by degree of predictability, and was equivalen t in the written and oral spelling conditions. Phonologically acceptab le alternative spellings (e.g.'wade' --> WAID) constituted the majorit y of errors. More peripheral processes in writing were assessed by cop ying and cross-case transcription of single letters. Subjects were mor e successful at copying within case than transcribing across case. Per formance was also better-substantially so for the mild DAT group-when the target response in either task was an upper- rather than a lower-c ase letter. There was considerable heterogeneity in performance on the spelling and the letter tasks. Some patients (even in the more affect ed DAT group) were unimpaired on both tasks, suggesting that dysgraphi a is not a constant feature in early DAT. When writing deficits do bec ome apparent, in the earliest stages of the disease the pattern is mos t likely to be one of mild surface dysgraphia, a form of central dysgr aphia; impairments in more peripheral aspects of writing tend to emerg e once the disease has progressed beyond the minimal stage. (C) 1997 E lsevier Science Ltd.