The article discusses the potential of three assessments of language function in the diagnosis of early dementia. Seventy patients (mean age 68.0 yr) attending a memory clinic were assessed using three language tests: the Boston Naming Test, a semantic, and a phonemic word fluency measure. Results of these assessments were compared with those of clinical diagnosis including the Mini-Mental State Examination. The patients were classified by probable diagnosis as (i) dementia (N=23), (ii) minimal cognitive impairment ( N = 18) and (iii) other, mainly depression (N=29). Of the 23 patients in the dementia group, 18 (78.%) had a deficit on the Boston Naming Test, while only 1 1 (47.8%) were classified as demented on the Mini-Mental State Examination using a cut point of <24. Nine of the 18 patients (50%) with minimal cognitive impairment had a deficit using the Boston Naming Test, while one did using the Mini-Mental State Examination. Factors such as age, sex and language of origin, which may have influence on language performance, are discussed. Age did not affect performance, but sex and language of origin did appear to. It is concluded that there is evidence for the inclusion of certain semantic language tests in any assessment of early dementia.
KEY worn-Language, naming, dementia
The breakdown of language that occurs in moderate to severe dementia is well established, and a sequence of deterioration has been identified in senile dementia of the Alzheimer type (SDAT). The first changes occur in language tasks, such as naming, which use the semantic system, ie that aspect of the language system concerned with the meaning of words. These are followed by deviations and simplifications of syntax (grammar), which in turn are followed by phonemic breakdown (disordered use of sounds) (Appell et al., 1982).
Recently, language changes have also been recognized in early dementia. Martin and Fedio (1983) and Botwinick et af. (1986) detected deterioration in naming ability in patients with mild SDAT. Faber-Langendoen et al. (1988) used an