Loss of word-meaning with spared object semantics in a case of mixed primary progressive aphasia

This article provides a detailed assessment of patient HT with a history of progressive language deterioration of approximately 6 years presenting now as a fluent jargon aphasic with severe impairment of both speech production and comprehension. Neuropsychological testing of non-verbal cognitive functions showed no impairment, leading to the assumption of primary progressive aphasia (PPA). Contrary to the clinical criteria of the known PPA-subtypes there was nearly parallel decline of word comprehension and motor speech. HT also showed a significant dissociation between verbal and non-verbal semantic abilities resulting in severely impaired word comprehension with object semantics relatively spared. MRI scanning revealed pronounced focal atrophy of the left anterior temporal lobe and the left perisylvian region with relatively spared right temporal involvement. The clinical diagnostic criteria for PPA-subtypes do not seem to apply to the language features shown by our patient. The similarities and distinctions to semantic dementia and progressive non-fluent aphasia (PNFA) as subtypes of PPA will be discussed. The distinction between PNFA and SD may represent an oversimplification of the clinical presentations of PPA. It is also suggested that a mixed version of primary progressive aphasia should be taken into consideration as accepted clinical subtype.