Recovery of swallowing after dysphagic stroke relates to functional reorganization in the intact motor cortex

Background & Aims: The aim of this study was to determine the mechanism for recovery of swallowingafterdysphagicstroke. Methods: Twenty-eight patients who had a unilateral hemispheric stroke were studied 1 week and 1 and 3 months after the stroke by videofluoroscopy. Pharyngeal and thenar electromyographic responses to magnetic stimulation of multiple sites over both hemispheres were recorded, and motor representations were correlated with swallowingrecovery. Results: Dysphagia was initially present in 71% of patients and in 46% and 41% of the patients at 1 and 3 months, respectively. Cortical representation of the pharynx was smaller in the affected hemisphere (5 ± 1 sites) than the unaffected hemisphere (13 ± 1 sites; P ≤ 0.001). Nondysphagic and persistently dysphagic patients showed little change in pharyngeal representation in either hemisphere at 1 and 3 months compared with presentation, but dysphagic patients who recovered had an increased pharyngeal representation in the unaffected hemisphere at 1 and 3 months (15 ± 2 and 17 ± 3 vs. 9 ± 2 sites; P ≤ 0.02) without change in the affected hemisphere. In contrast, thenar representation increased in the affected hemisphere but not the unaffected hemisphere at 1 and 3 months (P ≤ 0.01). Conclusions: Return of swallowingafterdysphagicstroke is associated with increased pharyngeal representation in the unaffected hemisphere, suggesting a role for intact hemisphere reorganization in recovery