Development and Evaluation of stimulation strategies for the Improvement of the pharyngeal swallowing by an automated direct stimulation of N. hypoglossus in neurogenic swallow disorders

• Applicant: Professor Dr. Rainer Seidl
• Subject Area: Otolaryngology, Phoniatrics and Audiology
• Term: from 2018 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 398890253

The main goal of the proposed research project is to prove of concept of an implantable neuroprosthesis for the treatment of swallowing disorders. In the context of this project a controlled stimulations of the N. hypoglossus will be tried on awake patients. Those patients suffer from a neurogenic dysphagia, that prevents a sufficient elevation of the larynx. A real-time detection of the patient’s swallow intention will be used to support the voluntary onset of the swallow by electro stimulation and enable a save swallow process. The basis of the stimulation is a measurement system that has been developed under the supervision of the applicant, that can safely detect a swallow in real-time based on a bioimpedance and an electromyography measurement. This system shall be extended by a direct stimulation of the N. hypoglossus, to support the elevation of the larynx. Within the project, existing algorithms will be extended to detect swallow intentions and incomplete swallows. For that reason, the automatic detection must be adapted to patients and an inertial sensor must be integrated in the system do detect chewing movements. Further, a procedure needs to be derived that uses an endoscope and the measurement system to find the best suited position of the hypoglossus-electrode during implantation. The sufficient placement of the electrode is an important requirement for a successful stimulation. The implantation will be performed on patients that suffer from a dysphagia because of a limited elevation of the larynx (e.g. stem stroke), that can’t be further improved after a conservative therapy. This result will be evaluated by videofluoroscopy. After implantation and healing of the wounds, different stimulation strategies will be tested. It will be evaluated whether a preloading of the muscles during swallowing or imitation of the larynx movement by controlled electronic stimulation can provide the needed support of the swallowing process. Finally, a combination of both techniques will lead to an individually adapted stimulation strategy for each patient. The goal is an aspiration free swallow, with a stimulation intensity that is controlled by the stimulation system. After the evaluation is done using videofluoroscopy, the stimulation electrodes will be removed.The project will be finished after two years.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Thomas Schauer