Clinical assessment and management of adult cochlear implantation for single-sided deafness: ACIA guidelines
USA: A recent article published in Ear and Hearing reports American Cochlear Implant Alliance Task Force guidelines for clinical assessment and management of adult cochlear implantation for single-sided deafness.
There has been an expansion in the indications for cochlear implantation and including individuals with profound sensorineural hearing loss in the impaired ear and normal hearing (NH) in the contralateral ear, known as single-sided deafness (SSD). For the clinical assessment and management of adult cochlear implant candidates and recipients with SSD, there are additional considerations compared to conventional cochlear implant candidates with bilateral moderate to profound sensorineural hearing loss.
The report by Margaret T Dillon, the University of North Carolina at Chapel Hill, Chapel Hill, NC, and colleagues reviews the current evidence relevant to the assessment and management of adults with SSD. The authors conducted a systematic review of published studies that examined outcomes of cochlear implant use on measures of speech recognition in sound source localization, quiet and noise, quality of life, and tinnitus perception for this patient population.
Expert consensus and systematic review of the current literature were combined to provide guidance for the clinical assessment and management of adults with SSD.
Based on the current evidence and the results of the systematic review, the following guidelines are recommended for the preoperative evaluation and post-activation assessment and management of adults with SSD:
- It is recommended that individuals with sudden and/or rapid progression of SSD undergo standard medical workup and monitoring to determine if the hearing spontaneously improves or is recoverable with treatment, and that cochlear implantation should not occur earlier than 3 to 6 months after the sudden hearing loss to allow ample time for potential recovery of hearing. The potential exception to this is cases exhibiting evidence of progressive ossification (e.g., meningitis, after vestibular schwannoma resection, otic capsule fracture) where early implantation may be advantageous.
- Consideration of the potential for significant bilateral hearing loss is warranted, as well as the benefits of early implantation of the impaired hearing ear for long-term performance benefit.
- Preoperative imaging may include MRI with or without temporal CT. In most cases of acquired adult-onset SSD, an MRI alone is sufficient to evaluate for retrocochlear lesions, labyrinthine ossification, and inner ear malformations.
- Cases of advanced cochlear ossification, severe labyrinthine dysplasia, and cochlear nerve aplasia are potential contraindications for cochlear implantation, particularly in the setting of SSD where there is a heightened risk of device non-use.
- Some consideration is recommended for the potential effect of long durations of SSD on functional outcomes; however, prolonged duration of deafness in an adult with post-lingual onset is not a contraindication to cochlear implantation. Additional consideration is recommended for an adult with congenital SSD onset. Prolonged duration of deafness combined with congenital SSD onset may result in limited CI outcomes.
- Advanced age is not a contraindication for cochlear implantation. Consideration for cochlear implantation should prioritize the overall health of the individual as opposed to the chronological age at implantation.
- Reduced tinnitus severity is frequently reported after cochlear implantation and/or with CI use. It is recommended to obtain subjective measures preoperatively to establish a baseline of tinnitus severity that can be compared to postoperative and post-activation perceptions.
- It is recommended that non-surgical options are discussed with adult cases of SSD, and where possible, that patients are offered a trial with a non-surgical hearing technology before undergoing cochlear implantation.
- Preoperative counseling for cochlear implantation typically includes a description of the surgical procedure and associated postoperative management, CI devices, and mapping and assessment follow-up recommendations/protocols. It is recommended that the counseling of CI candidates with SSD also include a discussion of alternative hearing technologies for SSD, the implications of no treatment, CI device considerations, and realistic expectations.
- The preoperative and post-activation test battery should include subjective questionnaires to assess the perceived benefit of CI use, quality of life, and/or tinnitus severity.
- For CI recipients with preoperative moderate or better acoustic low-frequency hearing detection thresholds in the affected ear, hearing preservation should be monitored postoperatively by assessment of unaided hearing detection thresholds.
- One consideration when assessing the impaired ear for cases of SSD is the need to isolate the input from the contralateral, normal-hearing ear. Test methods used to isolate the input to the affected ear during the measurement of aided sound field thresholds and speech recognition include (1) use of direct audio input technology, (2) plugging the contralateral ear and placing a circumaural phone over the pinna, and (3) presenting masking to the contralateral ear via an insert phone and placing a circumaural phone over the pinna.
- It is recommended that the test battery for adults with SSD also include the assessment of spatial hearing, such as speech recognition in spatially-separated noise.
- For the behavioral measurement of electric threshold levels, it is recommended to plug the normal-hearing ear with an insert plug to limit the influence of environmental noise. For the behavioral measurement of MCL levels, the normal-hearing ear may remain plugged during procedures to rank loudness for individual channels and to balance loudness across channels.
- Wear time of the CI is associated with outcomes for adults with SSD. A minimum of 8 hours of device use per day is recommended.
- Auditory training is recommended within the initial months of CI use.
"For adults with SSD, cochlear implantation is an effective treatment option," the researchers wrote. "Our report provides guidance for the preoperative evaluation and post-activation assessment and management of adults with SSD based on the current evidence."
"Further research is needed to investigate the patient and device variables that may influence the performance of adult CI users with SSD, and optimal aural rehabilitation procedures unique to this patient population," they concluded.
Reference:
Dillon, Margaret T.1; Kocharyan, Armine2; Daher, Ghazal S.2; Carlson, Matthew L.2; Shapiro, William H.3; Snapp, Hillary A.4; Firszt, Jill B.5. American Cochlear Implant Alliance Task Force Guidelines for Clinical Assessment and Management of Adult Cochlear Implantation for Single-Sided Deafness. Ear and Hearing: August 22, 2022 - Volume - Issue - 10.1097/AUD.0000000000001260 doi: 10.1097/AUD.0000000000001260
