Neurorehabilitation strategies for poststroke oropharyngeal dysphagia: from compensation to the recovery of swallowing function

Oropharyngeal dysphagia (OD) is very prevalent amongpoststroke patients, causing severe complications but lacking specificneurorehabilitation treatment. This reviewcovers advances in thepathophysiology, diagnosis, andphysiologicallybased neurorehabilitation strategies forpoststrokeOD. The pathophysiology of oropharyngealbiomechanics can be assessed by videofluoroscopy, as delayedlaryngeal vestibule closure is closely associatedwith aspiration. Strokemay affect afferent or efferent neuronal circuits participating in deglutition. The integrity of oropharyngeal-cortical afferent pathways can be assessed by electroencephalography through sensory-evoked potentials by pharyngeal electrical stimulation, while corticopharyngeal efferent pathways can be characterized by electromyography through motorevoked potentials by transcranial magnetic stimulation. Dysfunction in both cortico-mediated evoked responses is associated with delayed swallow response and aspiration. Studies have reported hemispherical asymmetry on motor control of swallowing and the relevance of impaired oropharyngeal sensitivity on aspiration. Advances in treatment include improvements in compensatory strategies but aremainly focused on (1) peripheral stimulation strategies and (2) central, noninvasive stimulation strategies with evidence of their clinical benefits. Characterization of poststroke OD is evolving from the assessment of impaired biomechanics to the sensorimotor integration processes involved in deglutition. Treatment is also changing from compensatory strategies to promoting brain plasticity, both to recover swallow function and to improve brain-related swallowing dysfunction.