Vocal Cord Paralysis is a state which happens to most people who have been suffering from a stroke, an injury on the head or even after effects of other diseases. As a result, the person may suffer from difficulties in talking, breathing and also swallowing. The whole damage is done on the elastic bands of the muscle tissue that helps us to talk. The best treatment available for such a condition is a surgery or even speech therapy through which the patient may at least be able to speak a little.
Researchers are trying to find a better way to make the person speak like before. For this, they have introduced a hybrid approach by placing electrodes under the skin so as to bring back the movement in the vocal cord by stimulating the nerves that is dead in that area.
The vocal cord starts functioning only when it is closed. That is, when a person speaks, the air from the lungs hits the closed vocal cords and makes them vibrate and thus produces the corresponding sound. When a person does not speak, the vocal cords stay open so that the air passage is not blocked. In the case of vocal cord paralysis, the vocal cord does not close and so causes difficulties in speech. There will also be problem with food and water intake as they are prone to go directly to the lungs.
The electrodes will be fixed to the side of the throat and the nerves that are responsible for the vocal cord movement can be stimulated using electrical signals. The electrode will be placed in a pad which will have 32 pins. This pad will be inserted through the first few layers of the skin near the throat. Each pin will be stimulated individually depending on the location of the inactive nerves. The stimulation will be given by a small electrical device that will be attached to the patients’ belt. A wire will be connected to the device whose other end will be connected to the electrode pad.
But there are some problems in developing such a device as well. The first problem is that the nerves that are to be stimulated are placed in large groups and it is very difficult to access the ones that have damaged the vocal cords. The vocal cords are placed in the neck area which is covered with soft muscles. These muscles should be handled carefully as they are responsible for the movement of the head as well as the breathing process.
The next question is regarding the amount of stimulation that the nerves will receive. The damage due t the vocal cord paralysis mostly occurs at the end of the nerve – close to the larynx. So, an external stimulation may not be enough to make the nerve active as electrical signal will not reach the muscle.
The whole idea is being developed at the Virginia Polytechnic Institute and State University in Blacksburg by Prof. Alexander Leonessa and his assistant researchers.
Though the technique described sounds exciting, the research may take years. To make this happen, Prof. Alexander Leonessa was recently awarded $480,000 by the National Science Foundation Faculty Early Career Development. The progress in this technology will surely bring good to the people suffering from vocal cord paralysis.