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The nature of naming errors in primary progressive aphasia versus acute post-stroke aphasia.

OBJECTIVE
To compare the distribution of error types across subgroups of primary progressive aphasia and poststroke aphasia in different vascular locations.


METHOD
We analyzed naming errors in 49 individuals with acute left hemisphere ischemic stroke and 55 individuals with three variants of primary progressive aphasia. Location of atrophy or ischemic stroke was characterized using MRI.


RESULTS
We found that distribution of error types was very similar across all subgroups, irrespective of the site or etiology of the lesion. The only significant difference across groups was the percentage of circumlocutions (F(7, 96) = 3.02, p = .005). Circumlocution errors were highest among logopenic variant PPA (24%) and semantic variant PPA (24%). Semantic coordinate errors were common in all groups, probably because they can arise from disruption of different cognitive processes underlying naming and, therefore, from different locations of brain damage.


CONCLUSIONS
Semantic errors are common among all types of primary progressive aphasia and poststroke aphasia, and the type of error depends in part on the location of damage.