Neurostimulation for the treatment of disturbed pharyngeal sensitivity as a major cause of neurogenic dysphagia

• Applicants: Professor Dr. Rainer Dziewas; Professorin Dr. Sonja Suntrup-Krüger; Professor Dr. Carsten Hermann Wolters
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 283033897

Swallowing is processed in the central and peripheral nervous system in a sophisticated way, with oropharyngeal afferences ensuring continuous adaptation of the movement programme, thereby being crucial for intact swallow function. Impairment of sensory feedback results in a complex disturbance of swallowing.Stroke is one of the main reasons for neurogenic dysphagia. More than 50% of patients are affected in the acute stage. Impairment of laryngopharyngeal sensitivity constitutes a major reason for the mostly complex swallowing disturbance pattern. Apart from reduced food intake followed by malnutrition and dehydration, aspiration pneumonia is a common consequence, which is associated with significant increase in mortality. 10 to 15% of stroke patients need intubation, among others because of respiratory complications. After termination of artificial ventilation severe post-extubation-dysphagia often persists due to multietiological laryngopharyngeal sensory impairment. The latter constitutes a risk factor for reintubation and recurrent pneumonia and is associated with prolonged hospital stay and poor outcome.The focus of treatment studies is shifting from conventional exercise-based swallow therapy towards approaches that modulate the underlying neural systems. Transcranial Direct Current Stimulation and Pharyngeal Electrical Stimulation constitute two of these novel treatment options. Following comprehensive studies by the applicants on the cortical representation of swallowing and neuronal reorganization in the spontaneous course of neurologic diseases as well as following therapeutic interventions, the aim of the current project is to evaluate the therapeutic effect of the above mentioned neurostimulation methods on impaired pharyngeal sensibility as the pathophysiological substrate of stroke-related dysphagia.At first, magnetoencephalographic measurements of an antagonistic effect of both stimulation methods on experimentally reduced cortical swallow activation induced by pharyngeal anaesthesia will be done in healthy subjects. Moreover, cortical representation of pharyngeal sensibility will be characterized in dysphagic stroke patients and correlated with dysphagia characteristics as seen in fiberendoscopic swallow evaluation. Next, a randomized clinical trial on acute stroke patients with post-extubation dysphagia will be carried out. In the treatment arm Pharyngeal Electrical Stimulation will be applied in defined time intervals. Effects of stimulation on reintubation rate, incidence of pneumonia and swallow function will be evaluated.

• DFG Programme: Research Grants