Language disintegration in dementia: effects of etiology and severity.

The speech characteristics on a standardized picture description task of 26 subjects with presumed senile dementia of the Alzheimer type (SDAT) and 13 subjects with stroke-related dementia (SRD) were compared to 15 normal subjects over age 59 years. Compared to the normal subjects, the dementia subjects used fewer total words, fewer unique words, fewer prepositional phrases, fewer subordinate clauses, and more incomplete sentence fragments. Lexical deficits tended to be more severe than syntactic ones, confirming prior suggestions that lexicon is more vulnerable to disruption in dementia than syntax.