Early aphasia rehabilitation is associated with functional reactivation of the left inferior frontal gyrus: a pilot study

Abstract

Background and purpose: Early poststroke aphasia rehabilitation effects and their functional MRI (fMRI) correlates were investigated in a pilot, controlled longitudinal study.

Methods: Twelve patients with mild/moderate aphasia (8 Broca, 3 anomic, and 1 Wernicke) were randomly assigned to daily language rehabilitation for 2 weeks (starting 2.2 [mean] days poststroke) or no rehabilitation. The Aachen Aphasia Test and fMRI recorded during an auditory comprehension task were performed at 3 time intervals: mean 2.2 (T1), 16.2 (T2), and 190 (T3) days poststroke.

Results: Groups did not differ in terms of age, education, aphasia severity, lesions volume, baseline fMRI activations, and in task performance during fMRI across examinations. Rehabilitated patients significantly improved in naming and written language tasks (P<0.05) compared with no rehabilitation group both at T2 and T3. Functional activity at T1 was reduced in language-related cortical areas (right and left inferior frontal gyrus and middle temporal gyrus, right inferior parietal lobule and superior temporal gyrus) in patients compared with controls. T2 and T3 follow-ups revealed a cortical activation increase, with significantly greater activation in the left hemisphere areas in rehabilitated patients at T2 and T3, and a time×treatment effect at T2 in the left inferior Broca area after rehabilitation. Left inferior frontal gyrus activation at T2 significantly correlated with naming improvement.

Conclusions: Early poststroke aphasia treatment is useful, has durable effects, and may lead to early enhanced recruitment of brain areas, particularly the left inferior frontal gyrus, which persists in the chronic phase.

Keywords: aphasia; language therapy; magnetic resonance imaging, functional; neuroimaging; rehabilitation outcome.