The effect of constraint-induced aphasia on language recovery and functional reorganization of the brain in Broca′s aphasia after a stroke

Abstract

Objective To explore the impact of constraint-induced aphasia therapy (CIAT) on language function and neural activity in patients with chronic Broca′s aphasia. Methods Two chronic aphasics whose use of language was recovering after standard language therapy were selected to receive 1.5 h of CIAT twice daily for two weeks (30 hours in total). Before and after the CIAT they were tested using a block-designed picture-naming task, fMRIs were taken and their use of language was examined. Results The language function assessments showed relatively large improvements in the subjects′ use of language after 4 weeks of conventional language training, but not much further change after 8 and 12 weeks. After the two weeks of CIAT, their language function improved further to a certain extent. fMRI showed increased activation in the left inferior frontal gyrus with or without enhanced activation in the left hemisphere, and reduced activation in the right inferior frontal gyrus. Conclusions Functional reorganization induced in the brain by CIAT was associated with up-regulation of the left inferior frontal gyrus or down-regulation of the right inferior frontal gyrus. Even the whole language network may have been modified. Key words: Stroke; Broca′s aphasia; Language training; Constraint-induced aphasia therapy; Brain reorganization; Functional magnetic resonance imaging