The anatomy of aphasia revisited

TLDR

The anatomy of aphasia has been challenged by several recent studies. The study aims to determine lesion locations associated with various types of aphasic disorders in stroke patients and to examine methodological discrepancies. We examined 107 stroke patients with a standardized aphasia battery and MRI, had three blinded examiners rate abnormalities in 69 predefined regions, and used classification tree testing to identify regions linked to each aphasic disorder. Classification tree analysis correctly classified 67%–94% of patients, showing that lesion location is the main determinant of aphasic disorders at the acute stage, and most clinical‑radiologic correlations supported the classic anatomy of aphasia.

Abstract

To determine lesion locations associated with the various types of aphasic disorders in patients with stroke.The anatomy of aphasia has been challenged by several recent studies. Discrepancies are likely to be due to methodologic issues.We examined 107 patients with a standardized aphasia battery and MRI. Three examiners blinded to the clinical data rated signal abnormalities in 69 predetermined regions of interest. The statistical procedure used classification tree testing, which selected regions associated with each aphasic disorder.1) Nonfluent aphasia depended on the presence of frontal or putaminal lesions; 2) repetition disorder on insula-external capsule lesions; 3) comprehension disorder on posterior lesions of the temporal gyri; 4) phonemic paraphasia on external capsule lesions extending either to the posterior part of the temporal lobe or to the internal capsule; 5) verbal paraphasia on temporal or caudate lesions; and 6) perseveration on caudate lesions. These analyses correctly classified 67% to 94% of patients.Lesion location is the main determinant of aphasic disorders at the acute stage. Most clinical-radiologic correlations supported the classic anatomy of aphasia.