A longitudinal study of reading ability in patients suffering from dementia.

The aim of this study was to investigate whether reading is a preserved ability in patients suffering from dementia, as was first suggested by Nelson and McKenna (1975). The 57 patients included in the study had possible or probable Alzheimer's disease or similar degenerative conditions and were assessed longitudinally. Their performance on the National Adult Reading Test [(NART); Nelson, 1982, 1991] is compared to that on a shortened version of the WAIS-R. It is found that although performance on the NART does decline gradually over time, the deterioration on formal tests of IQ is more rapid and more severe. It seems that the decline in reading across the group is due to those patients who have a lower verbal IQ (VIQ) than performance IQ (PIQ). It is concluded that generally the NART can be used as a predictor of the premorbid intellectual functioning of a patient with dementia, given that the VIQ is greater than PIQ.