Performance in specific language tasks correlates with regional volume changes in progressive aphasia

Background: Patterns of language impairment have long been used clinically to localize brain damage in stroke patients. The same approach might be useful in the differential diagnosis of progressive aphasia owing to neurodegenerative disease. Objective: To investigate whether scores on 4 widely used language tasks correlate with regional gray matter loss in 51 patients with progressive language impairment owing to neurodegenerative disease. Method: Scores in the Boston Naming Test and in the "repetition" 11 sequential commands" and the "language fluency," subtests of the Western Aphasia Battery were correlated with voxel-wise gray matter volumes using voxel-based morphometry. Results: Significant positive correlations were found between each language task and regional brain volumes: (1) naming and the bilateral temporal lobes; (2) sentence repetition and the left posterior portion of the superior temporal gyrus; (3) sentence comprehension and the left dorsal middle and inferior frontal gyri; and (4) fluency of language production and the left ventral middle and inferior frontal gyri. Discussion: Performance on specific language tasks corresponds to regional anatomic damage in aphasia owing to neurodegenerative disorders. These language tests might be useful in the differential diagnosis of primary progressive aphasia variants that have been previously associated with damage to corresponding anatomic regions.