- Hannah Cleaver
- Reuters Health
A “pacemaker for the tongue” could soon help victims of mouth cancer or accidents to control a reconstructed tongue built from transplanted muscle, animal studies in Germany suggest.
Currently, surgeons can fashion replacement tongues from neck muscles for people who lose their tongue to cancer or trauma. The muscles are grafted onto the base of the person’s original tongue.
But controlling the rebuilt organ, in order to eat and talk, is a major problem and reconstructed tongues need to be kept active to avoid shrinkage through disuse. “The reconstructed tongue initially makes passive movements, which are produced by contractions of the surrounding floor of the mouth as well as pharynx and chewing musculature,” said Professor Stephan Remmert, from Luebeck University Hospital, at last week’s German Ear, Nose and Throat Conference in Baden-Baden.
To give patients better control of the tongue, Remmert is using pacemaker technology to boost nerve signals to the reconstructed organ. He told Reuters Health that the main aim of the work was to filter the most important signals that the brain sends to the main tongue nerve, the hypoglossus. “Then we can amplify the signal and send it on to the new musculature,” Remmert said. “It has to be amplified enough to generate quite powerful movements.” In experiments on domestic pigs, the group is surrounding the severed end of the hypoglossus with electrodes to measure, reproduce and send its signals. Much of the other technology needed has already been developed, or is in development, much of it from the cardiac pacemaker field, he said.
Although the results of the animal experiments are promising, they will not be directly transferable to people. Still, Professor Remmert thinks clinical trials on people could be feasible within 2 or 3 years. As with heart pacemakers, he said the tongue pacemaker would eventually be implanted–under the collarbone and connected to the tongue by a wire.