Pattern generators and more. Cortical control mechanisms of swallowing

BACKGROUND: Swallowing as a neurophysiological process has recently attracted much interest. Knowledge of cortical involvement in particular has raised hope that a novel form of dysphagia therapy might be possible by means of cortical stimulation. METHOD: For this systematic review a selective literature research in PubMed has been carried out. RESULTS: The cortex is not only involved in the initiation of swallowing, but also during pharyngeal and esophageal phases. In addition, there appears to be a hemispheric dominance both for swallowing and its individual phases. DISCUSSION: In light of recent study results, the theory of the pattern generators' autonomy must be abandoned, since pattern generators seem to be influenced rather by the cortex. During the recovery of unilateral impairments, the intact hemisphere seems to play a significant role due to cortical reorganisation processes. Several studies indicate that repetitive transcranial stimulation, and thereby modulation of cortical areas as a means of dysphagia therapy, could be beneficial.