Etiological factors of facial nerve stimulation in cochlear implant users

Abstract

   Cochlear implantation is a high-tech method of rehabilitation of persons with complete deafness. However, cochlear implantation in patients may be accompanied by a number of difficulties due to the peculiarities of the structure of the cochlea, the relative position of anatomical structures relative to it and the nature of the acquired pathology of the inner ear. The reaction of the facial nerve during stimulation of one of the electrodes of the cochlear implant system is a common complication that can lead to a deterioration in the patient’s quality of life due to significant discomfort and restrictions on the use of the cochlear implant system. The debut of twitching of facial muscles in patients after cochlear implantation can occur both at the stage of connecting the speech processor and at the stages of further rehabilitation, which according to world literature can reach an interval of 10 years from the moment of surgery. Anatomical features of the cochlea, its interposition with the facial nerve, changes in the bone labyrinth, further progression of remodeling or ossification of the cochlea play a significant role in the development of symptoms of facial nerve stimulation in patients with sensorineural hearing loss of the IV degree, including at the stage of subsequent settings of the speech processor. The frequency of occurrence of this complication in various literature sources varies from 1 to 14.9 %. The purpose of this work is to review the world literature on the etiology of facial nerve stimulation in users of cochlear implants, highlighting the main theories of the origin of non-auditory sensations in this category of patients, since the data conducted in various studies are variable, and with a certain etiology reaches 38 %.