Alexia in dementia of the Alzheimer's type.

The reading aloud of single words in 16 subjects with dementia of the Alzheimer's type (DAT) was compared with the performance of control subjects. The assessment included a computerised test-battery designed to assess word recognition ability and the efficiency of the two underlying reading strategies; the lexical and the non-lexical strategy. The DAT patients had severe difficulties in word recognition ability. Both accuracy score and reaction time were significantly impaired compared with the results in the control group. Furthermore, the results demonstrated that both the lexical and the non-lexical reading strategies were impaired. There was a significant correlation between reading performance and severity of dementia. However, no significant association between reading performance and age of onset or family history of dementia could be observed.