Long-term reorganization of human motor cortex driven by short-term sensory stimulation.

Removal of sensory input can induce changes in cortical motor representation that reverse when sensation is restored. Here we ask whether manipulation of sensory input can induce long-term reorganization in human motor cortex that outlasts the initial conditioning. We report that for at least 30 minutes after pharyngeal stimulation, motor cortex excitability and area of representation for the pharynx increased, while esophagus representation decreased, without parallel changes in the excitability of brainstem-mediated reflexes. Therefore increased sensory input can drive long-term cross-system changes in motor areas of the cerebral cortex, which suggests that sensory stimulation might rehabilitate dysphagia, a frequent consequence of cerebral injury.