Epidemiology Hearing Impairment and Bilateral Cochlear Implantation

Question: Discuss about theEpidemiologyfor Hearing Impairment and Bilateral Cochlear Implantation. Answer: Introduction Hearing impairment is prevalent all over the world. It has been found that 550 million people are suffering from hearing loss and about 60 million people are suffering from severe hearing impairment (1). Sensorineural hearing loss is among one of the most usual kind of hearing impairments. It is caused by the defect of cochlea, referred to as cochlear impairment. However, hearing aids are considered as the first choice for such hearing loss. In cases of severe hearing impairments, cochlear devices are used (2). In this assignment, the chosen intervention is bilateral cochlear implants on adults. The systematic review articles have been chosen based on randomized controlled trials and an evidence table has been included. Introduction to Intervention Cochlear implants are tiny; intricate electronic device which helps in providing the ability of listening to sound in persons who are severely deaf. These devices help in receiving sound, processing, transmitting and converting into electrical signal. Then it is sent to the brain via direct stimulation of the nerve cells for auditory functioning. The device is made up of a microphone, a processor unit for speech, transmitter or receiver and an array of electrodes (3). It has been found that cochlear implantations are successful in most of the cases. The cochlear implantations have been found to be a standard treatment for hearing loss over the last few decades. The bilateral cochlear implants are used for profound hearing impairments and they are implanted in both the ears to facilitate hearing with both the ears (4). Description of Search Strategy The electronic databases are used for the evidence based systematic review. The electronic databases like COCHRANE, MEDLINE, Embase has been searched in English language. The studies were published within the period of 2012 to 2016. Discussion of Evidence Qualityand Findings of the Study The three systematic reviews have been selected for the assignment provides with the highest level of evidence on the concerned issue. The Level 1 of the hierarchy of evidence with systematic review involving randomized controlled trial. The systematic reviews demonstrate well that the cochlear implants are beneficial in improving the hearing loss. It was found that there were less risks of bias in the use of the devices. Even in complex situations, it was reported to be advantageous. As compared to unilateral cochlear devices, the bilateral devices were beneficial in speech perception under conditions like noise but in quiet and localization, it did not show much significance. The bilateral implants were found to be more effective clinically. It was found that the bilateral cochlear implants developed the hearing problems in patients with severe hearing loss. The cost effectiveness was also analyzed and bilateral cochlear implants were reported to be more affordable in context to co st as well as efficacy. The benefits of bilateral implantations were found mostly with deep insertion; however, it has an inherent limitation of head shadow. Table 1: Evidence Table Article Author and Date Evidence type (Study Design) Study objective Study findings Limitations 1. van Schoonhoven et al, 2013. Cochlear implantation in older adults: long-term analysis of complications and device survival in a consecutive series. Randomized controlled trial The aim of the selected study is to determine the impact of bilateral cochlear implantation on adults in comparison to unilateral cochlear implants for serving the extreme hearing loss (5). The study included 14 relevant other studies. The outcomes were measured based on speech perceptions, localization and self reported measures. One of the study showed that the bilateral implants were more advantageous in cases of speech perception in quiet; two studies showed that the bilateral implants are more beneficial in context to speech perception in noise. In case of localization, a consistency was found in the bilateral implants. However, in cases of self reported measures, the bilateral benefits were not significant (5). Pooling of all data were not possible from all the studies because of the heterogeneity. 2. Crathorne et al, 2012. Unilateral versus simultaneous bilateral cochlear implantation in adults: a randomized controlled trial. Brain Center Rudolf Magnus. Randomized controlled trial The aim of the study was to estimate and find the cost effectiveness of the implantation devices and a comparison between unilateral and bilateral implants in adults (6). In this systematic review, 19 studies were included. All the relevant studies of the systematic review reported that the bilateral implants were more beneficial in improving the adult hearing difficulties. The cost effectiveness of these implants were analyzed. It was found that the bilateral implant s were more effective (6). The cost effectiveness of cochlear implants were however determined, but more research in this context needs to be done. 3. Zhou et al, 2016. Effects of insertion depth on spatial speech perception in noise for simulations of cochlear implants and single-sided deafness. Randomized controlled trial The study aim was to determine the impact of depth of insertion of the cochlear implants in case of perception of speech and one-sided deafness (7). The study results found that in context to one-sided deafness the cochlear implantations showed prominent improvements in all depths of insertion. The most significant benefit was found with deepest insertion of the implant (7). The cochlear implantations were found to be effective in deepest insertion. Further studies on all insertion depths and analysis might be made to bring out more improved and diversified applicability of the devices. References: Stevens G, Flaxman S, Brunskill E, Mascarenhas M, Mathers CD, Finucane M. Global and regional hearing impairment prevalence: an analysis of 42 studies in 29 countries. The European Journal of Public Health. 2013 Feb 1;23(1). Hahne A, Mainka A, Leuner A, Mrbe D. Adult Cochlear Implant Users Are Able to Discriminate Basic Tonal Features in Musical Patterns: Evidence From Event-related Potentials. Otology Neurotology. 2016 Oct 1;37(9). Chen DS, Clarrett DM, Li L, Bowditch SP, Niparko JK, Lin FR. Cochlear implantation in older adults: long-term analysis of complications and device survival in a consecutive series. Otology neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2013 Sep;34(7). Smulders YE. Unilateral versus simultaneous bilateral cochlear implantation in adults: a randomized controlled trial. Brain Center Rudolf Magnus. 2016 Feb 4;119. van Schoonhoven J, Sparreboom M, van Zanten BG, Scholten RJ, Mylanus EA, Dreschler WA, Grolman W, Maat B. The effectiveness of bilateral cochlear implants for severe-to-profound deafness in adults: a systematic review. Otology Neurotology. 2013 Feb 1;34(2). Crathorne L, Bond M, Cooper C, Elston J, Weiner G, Taylor R, Stein K. A systematic review of the effectiveness and cost?effectiveness of bilateral multichannel cochlear implants in adults with severe?to?profound hearing loss. Clinical Otolaryngology. 2012 Oct 1;37(5). Zhou X, Li H, Galvin III JJ, Fu QJ, Yuan W. Effects of insertion depth on spatial speech perception in noise for simulations of cochlear implants and single-sided deafness. International Journal of Audiology. 2016 Jun 30.