Selective stimulation of facial muscles with a penetrating electrode array in the feline model.
Permanent facial nerve injury is a difficult challenge for both patients and physicians given its potential for debilitating functional, cosmetic, and psychological sequelae. Although current surgical interventions have provided considerable advancements in facial nerve rehabilitation, they often fail to fully address all impairments. We aim to introduce an alternative approach to facial nerve rehabilitation.



Acute experiments in animals with normal facial function.



The study included three anesthetized cats. Four facial muscles (levator auris longus, orbicularis oculi, nasalis, and orbicularis oris) were monitored with a standard electromyographic (EMG) facial nerve monitoring system with needle electrodes. The main trunk of the facial nerve was exposed, and a 16-channel penetrating electrode array was placed into the nerve. Electrical current pulses were delivered to each stimulating electrode individually. Elicited EMG voltage outputs were recorded for each muscle.



Stimulation through individual channels selectively activated restricted nerve populations, resulting in selective contraction of individual muscles. Increasing stimulation current levels resulted in increasing EMG voltage responses. Typically, selective activation of two or more distinct muscles was successfully achieved via a single placement of the multi-channel electrode array by selection of appropriate stimulation channels.



We have established in the animal model the ability of a penetrating electrode array to selectively stimulate restricted fiber populations within the facial nerve and to selectively elicit contractions in specific muscles and regions of the face. These results show promise for the development of a facial nerve implant system.



N/A.Laryngoscope, 2016 127:460-465, 2017.
Medical Scientist Training Program, University of California, Irvine, Irvine, California, U.S.A.
Ronald
R
Sahyouni
Department of Otolaryngology-Head & Neck Surgery, University of California, Irvine, Irvine, California, U.S.A.
Jay
J
Bhatt
Department of Otolaryngology-Head & Neck Surgery, University of California, Irvine, Irvine, California, U.S.A.
Hamid R
HR
Djalilian
School of Medicine, Department of Biomedical Engineering, University of California, Irvine, Irvine, California, U.S.A.
William C
WC
Tang
Department of Otolaryngology-Head & Neck Surgery, University of California, Irvine, Irvine, California, U.S.A.
John C
JC
Middlebrooks
Department of Otolaryngology-Head & Neck Surgery, University of California, Irvine, Irvine, California, U.S.A.
Harrison W
HW
Lin
D000818:Animals; D002415:Cats; D003196:Computer Graphics; D004195:Disease Models, Animal; D004558:Electric Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004576:Electromyography / Q000295:instrumentation*; D005152:Facial Muscles / Q000294:innervation* / Q000502:physiology*; D005154:Facial Nerve / Q000503:physiopathology*; D005158:Facial Paralysis / Q000503:physiopathology* / Q000628:therapy*; D009119:Muscle Contraction / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D009474:Neurons / Q000502:physiology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014741:Video Recording
Facial nerve; facial nerve implant; facial stimulation; multi-channel electrode array