Focused Laryngeal Stimulation

Brief summary of current research activities in the past five years centered on:

1. Artificial Control of Voice
2. Human laryngeal pacing in adduction for the control of aspiration after stroke and associated neurological assaults
3. Human laryngeal pacing in adduction for the control of inspiratory difficulty after bilateral recurrent nerve paralysis

Project 1: Dynamic Vocal Fold Adduction for Bilateral Paralysis

Bilateral vocal cord paralysis is a life threatening condition due to the inability of the larynx (voice box) to open during inspiration. It can follow as a complication of thyroid surgery, other trauma to the recurrent laryngeal nerve in the neck, base of skull or chest by motor vehicle or other accidents, compression from lung or thyroid cancer, cancer surgery, intubation and varieties of neurological conditions. The closed position of the vocal cords seen in such cases results in major compromise of the ability to breathe through the natural passages (nose and mouth), so that the inspiratory effort becomes only possible with a tracheotomy (neck breathing). Unfortunately, this surgery can have many complications, is socially difficult to bear, and is expensive due to necessary long -term care. Other surgeries that may open the laryngeal airway are destructive, technically difficult and may lead to aspiration (choking). The long term objectives of this research is to reversibly move the vocal cords apart to increase the airway and resume natural breathing without the inconveniences of destructive neck surgeries. Pilot studies done in the dog have shown frank vocal cord opening when a nerve implanted into the cricoarytenoideus (the only muscle able to open the larynx) was electrically stimulated. A FDA-approved implantable pacemaker was recently used to close the vocal cords of patients aspirating after stroke. We propose to use the same device to have patients voluntarily trigger laryngeal opening by flipping the switch of an external controller when they wish to breathe through the natural passages. Comparing vocal cord positions and breathing tests before and during stimulation will establish whether sufficient data are available to pursue clinical applications of laryngeal pacing after bilateral vocal cord paralysis.

Project 2: Human Laryngeal Pacing for Aspiration

An estimated 500,000 patients per year are affected in the United States by stroke-related dysphagia. Approximately half experience aspiration, which can lead to pneumonia and death. Surgical interventions carried to protect the lungs are usually irreversible, destructive to the upper airway and rarely prevent the need for enteral tube feeding. The long term objective of this research is to return missing coordination to the vocal folds and allow oral feeding without aspiration. Specifically, pilot studies using a FDA-approved implantable laryngeal stimulator have given encouraging results in two patients. However, sufficient preliminary data are necessary to support clinical feasibility of laryngeal pacing after stroke. An additional eight patients with videofuoroscopic evidence of aspiration and who have failed swallowing rehabilitation by the speech-language pathologist for one year or longer will be considered. Each will receive a stimulator implanted over the chest wall, linked to an electrode passed around the ipsilateral recurrent laryngeal nerve. Aspiration will be prevented by voluntary triggering glottic closure from a switch on the external controller of the device. Based on blind review, statistical comparison between the presence and absence of contrast material below the vocal folds with and without stimulation will establish whether sufficient data are available to pursue clinical applications of laryngeal pacing after stroke.

Dr. Broniatowski's research is supported by grants from The NeuroControl Company, The Surgical Foundation, The Veterans Administration and the National Institutes of Health.

PI: Michael Broniatowski, MD

Publications

(selected from 60 peer reviewed publications)

1. Broniatowski M, Ilyes LA, Jacobs GB, Rosenthal DI, Maniglia AJ, Nosé Y, Tucker HM: Electronic Control of Reinnervated Strap Muscles from intact Facial Musculature in the Rabbit. Otolaryngology-Head and Neck Surgery 97:441-445, 1987.
2. Broniatowski M, Ilyes LA, Jacobs GB, Nosé Y, Tucker HM: Dynamic Rehabilitation of the Paralyzed Face II. Electronic Control of Reinnervated facial Musculature from the Intact Contralateral side in the Rabbit. Otolaryngology-Head and Neck Surgery, 101: 309-13, 1989.
3. Grundfest-Broniatowski S, Broniatowski M, Davies CR, Kasick JC, Jacobs GB, Hermann RE, Tucker HM, Nosé Y: Artificial Myotatic Reflex: A potential avenue to fine motor control. Otolaryngology-Head and Neck Surgery, 101: 621-28,1989.
4. Broniatowski M, Grundfest-Broniatowski S, Davies CR, Jacobs GB, Nosé Y, Tucker HM: Artificial Agonist/Antagonist Coupling in the Paralyzed Face. I: Electronic Balance of Reinnervated Strap Muscles from Facial activity in the Rabbit. Laryngoscope, 99: 647-50, 1989.
5. Grundfest-Broniatowski S, Broniatowski M, Davies C, Jacobs G, Tucker H, Nosé Y: Fine control of reinnervated muscle: Dynamic rehabilitation in facial paralysis. Transactions of the ASAIO, XXXV: 484-86, 1989.
6. Broniatowski M, Grundfest-Broniatowski S, Chou SM, Nosé Y, Tucker HM. Correlation between histology and nerve excitability after reinnervation of paralyzed strap muscles in the rabbit. Otolaryngol Head Neck Surg 103: 889-96, 1990.
7. Broniatowski M, Davies CR, Jacobs GB, Grundfest-Broniatowski S, Nosé Y, Tucker HM. Electronic control of laryngeal spasm. I: Blockage of orthodromically induced action potentials in intact canine recurrent laryngeal nerves. Laryngoscope 100: 892-95, 1990.
8. Broniatowski M, Davies CR, Jacobs GB, Jasso J, Gerrity R, Tucker HM, Nosé Y. Excitation thresholds for nerves reinnervating the paralyzed canine larynx. Trans Am Soc Artif Inter Organs XXXVI: M432-34, 1990
9. Broniatowski M, Davies CR, Jacobs GB, Nosé Y, Tucker HM. Dynamic rehabilitation of the paralyzed face. III: Balanced coupling of oral and ocular musculature from the intact side in the canine. Otolaryngol Head Neck Surg 105: 727-33, 1991.
10. Broniatowski M, Azar K, Davies CR, Jacobs GB, Tucker HM: Selective control of spastic musculature in a canine model. ASAIO Journal, 38: 248-252, 1992.
11. Broniatowski M, Azar K, Davies CR, Jacobs GB, Tucker HM. Electronic Control of Laryngeal Spasm. II: Selective Blockage of Glottic Adduction by a Closed Loop in the Canine. Laryngoscope, 103: 734-740, 1993.
12. Broniatowski M, Dessoffy R, Azar K, Davies CR, Trott MS, Miller F, Tucker HM: Electronic integration of glottic closure and cricopharyngeal relaxation for the control of aspiration. A canine study. Otolaryngology-Head and Neck Surgery, 424- 429, 1995.
13. Broniatowski M, Vito KJ, Shah B, Shields RL, Kayali H, Secic M, Dessoffy R, Strome M. Contraction Patterns in Intrinsic
14. Laryngeal Muscles in the Canine. Otolaryngology-Head and Neck Surgery, Laryngoscope 106:1510-15, 1996.
15. Broniatowski M, Vito KJ, Shah B, Shields RL, Strome M. Control of Glottic Adduction for Aspiration by Orderly Recruitment in the Canine. Dysphagia. 12:93-7, 1997.
16. Broniatowski M, Dessoffy R, Strome M. Vagal Stimulation for reciprocal coupling between glottic and upper esophageal sphincter activities in the canine. Dysphagia 14: 196-203, 1999.
17. Broniatowski M, Grundfest-Broniatowski S, Nelson DW, Dessoffy R, Strome. Electronic Analysis of Intrinsic Laryngeal Muscle Contributions to Canine Sound Production. Annals Otol Rhinol Laryngol, 111: 542-52, 2002.
18. Broniatowski M, Grundfest-Broniatowski S, Tucker, HM, Tyler DJ. Artificial Voice Modulation in Dogs by Recurrent Laryngeal Nerve Stimulation: Electrophysiological Confirmation of Anatomic Data. Ann Otol Rhinol Laryngol, in press (March 2007).