Factors Predictive of Binaural Hearing Restoration by Cochlear Implant in Single-Sided Deafness.

INTRODUCTION: Cochlear implants (CIs) can restore binaural hearing in cases of single-sided deafness (SSD). However, studies with a high level of evidence in support of this phenomenon are lacking. The aim of this study is to analyze the effectiveness of CIs using several spatialized speech-in-noise tests and to identify potential predictors of successful surgery. METHODS: Ten cases underwent standard CI surgery (MEDEL-Flex24). The speech-in-noise test was used in three different spatial configurations. The noise was presented from the front (N0), toward the CI (NCI), and toward the ear (Near), while the speech was always from the front (S0). For each test, the speech-to-noise ratio at 50% intelligibility (SNR50) was evaluated. Seven different effects were assessed (summation, head shadow [HS], speech released of masking [SRM], and squelch for the CI and for the ear). RESULTS: A significant summation effect of 1.5 dB was observed. Contralateral PTA was positively correlated with S0N0-B and S0NCI-B (CIon and unplugged ear). S0N0-B results were positively correlated with S0N0-CIoff (p < 0.0001) and with S0Near-CIoff results (p = 0.004). A significant positive correlation was found between delay post-activation and HS gain for the CI (p = 0.005). Finally, the HS was negatively correlated with the squelch effect for the ear. CONCLUSION: CI benefits patients with SSD in noise and can improve the threshold for detecting low-level noise. Contralateral PTA could predict good postoperative results. Simple tests performed preoperatively can predict the likelihood of surgical success in reversing SSD.

The Use of a Robot to Insert an Electrode Array of Cochlear Implants in the Cochlea: A Feasibility Study and Preliminary Results.

INTRODUCTION: Cochlear implants (CIs) are commonly used for the rehabilitation of profound bilateral hearing loss. However, patients with substantial residual acoustic hearing are potential CI candidates. Because of both improvements in technology and advancements in surgical techniques, it may be possible to preserve hearing to some extent. For more than a decade, it has been suggested that robots are used to perform middle ear surgery. We evaluated the use of the RobOtol® otologic robot specifically to insert CI electrodes into the inner ear. METHODS: CI surgery with the conventional approach was performed under general anesthesia. The MED-El Flex 24-electrode array was inserted using RobOtol®. Video recordings were used to calculate the speed of insertion. The positions of the electrodes were evaluated using a cone beam CT. All subjects underwent pure-tone audiometry tests before and after surgery, and the pure-tone average (PTA) was calculated from 250 to 4,000 Hz. RESULTS: The robot inserted implants in 5 patients, and complete insertion of the electrode array was achieved. The speed of insertion of the electrode array was 0.88 ± 0.12 mm/s. The mean loss of the PTA for 5 frequencies (250, 500, 1,000, 2,000, and 4,000 Hz) was 13.60 ± 7.70 dB. Only 1 patient showed a loss of the PTA by >20 dB. For these 5 patients, the cone beam CT findings showed that all the electrode arrays were in the tympanic ramp and had a grade of 0. The results were compared with those obtained from a cohort of 17 patients who underwent manual implantation of a MED-El Flex 24-electrode array. CONCLUSION: To minimize disturbance to the cochlea while atraumatic electrode arrays are inserted, electrodes can be inserted at a constant, slow speed in the inner ear with the assistance of the RobOtol® robot in a normal clinical surgical setting.

Stapes Surgery for Otosclerosis in Patients Presenting with Mixed Hearing Loss.

OBJECTIVES: To evaluate the efficacy of stapes surgery in patients presenting with a preoperative mixed hearing loss (bone conduction thresholds ≥40 dB; 40 < air conduction thresholds (AC) < 85 dB). PATIENTS AND METHODS: A total of 30 patients (32 ears) with mixed hearing loss who underwent primary stapedotomy were evaluated. Audiometric parameters were assessed before and after surgery. Contralateral thresholds were also reported. The need for a hearing aid (HA) after surgery and its impact on quality of life were also measured. RESULTS: AC and word recognition at 40, 55 and 70 dB were significantly improved after stapes surgery. Only 16.6% of the patients needed an HA after surgery and reported being satisfied with the aid. CONCLUSION: Stapes surgery improved auditory function in patients with mixed hearing loss, allowing most patients to delay the need for an HA without worsening their quality of life.

Audiometric Results after Stapedotomy Operations in Patients with Otosclerosis and Preoperative Small Air-Bone Gaps.

OBJECTIVES: The efficacy of stapedotomies performed on patients with small air-bone gaps (<25 dB) was compared with the efficacy of the operation in patients who had otosclerosis with high air-bone gaps (≥25 dB). METHODS: This retrospective study evaluates the short-term postoperative air and bone conduction thresholds and air-bone gaps after 182 CO2 laser stapedotomies. RESULTS: A significantly smaller air-bone gap and lower air conduction thresholds after surgery were observed in the group of patients who underwent surgery with preoperative air-bone gaps of less than 25 dB. Bone conduction thresholds improve in the group with small air-bone gaps after surgery. CONCLUSIONS: The results after stapedotomies are good even if the preoperative air-bone gap is small and the overall risk of hearing deterioration due to stapes surgery remains low.

Intratympanic steroid therapy using the Silverstein Microwick™ for refractory sudden sensorineural hearing loss increases speech intelligibility.

OBJECTIVE: To determine whether delivery of methylprednisolone to the round window (administered for 10 days after the onset of the hearing loss) can improve hearing and, in particular, speech intelligibility, after the failure of conventional treatment for idiopathic sudden sensorineural hearing loss. RESULTS: Of the 26 patients enrolled in this non-randomized retrospective study, 14 patients (54%) showed an improvement in the pure tone average (PTA) and 12 remained unchanged. The topical steroid therapy brought about an overall improvement in PTA of 13.5 ± 7.3 dB for the 26 patients enrolled. The auditory capacity index, defined as the mean speech discrimination score obtained at 40, 55 and 70 dB, improved by 24.2 ± 8.7% in 26 patients. Among the 12 patients with a stable PTA, 9 showed an increase in speech intelligibility. CONCLUSION: Local administration of steroids to the inner ear through the round window route improves hearing and speech intelligibility in patients after failure of conventional therapy.

Intratympanic steroid therapy for refractory sudden sensory hearing loss: a 12-year experience with the Silverstein catheter.

BACKGROUND: Sudden sensorineural hearing loss (SSNHL) is commonly encountered in clinical practice. AIM/OBJECTIVE: Determine if local administration of corticosteroids to the inner ear can improve hearing and speech intelligibility after the failure of conventional treatment for SSNHL loss when administered for 10 days after the onset of the hearing loss in a large cohort of 77 patients. MATERIALS AND METHODS: A Silverstein MicroWick™ was placed under local anesthesia and endoscopic control in the round window niche, allowing self-administration of methylprednisolone twice daily for four weeks. RESULTS: An improvement of the pure tone average was shown in 31% of patients. Speech intelligibility improved significantly in 55% of the total cohort and in 34% of the population with a stable pure tone average. Among the 77 patients, 22% used a hearing aid. Only 14% of the patients were hearing-aid users in the group with an improvement in speech intelligibility as opposed to 31% in the failure group. CONCLUSION AND SIGNIFICANCE: Local administration of steroids to the inner ear through the round window route improves hearing and speech intelligibility in patients after failure of conventional therapy. The use of a hearing aid was reduced by 50% when speech intelligibility was improved.

Hearing preservation in cochlear implantation and drug treatment.

Insertion of an electrode array into the cochlea produces immediate damage to the inner ear, which is responsible for a hearing loss. In addition, a delayed hearing loss can be observed. In order to maximize hearing preservation after insertion of an electrode and to enhance the performance of the cochlear implant, it has been proposed to deliver pharmacological agents to the inner ear. Molecules can be administered locally to the inner ear through a direct perilymphatic perfusion or through the round window membrane. These modalities of treatment have already been successfully applied to some patients with inner ear diseases. In this paper, we will review some basic aspects of drug delivery to the inner ear to prevent the degeneration of the neurosensory hair cells and auditory neurons, and the actual applicability to humans in order to maintain hearing function after the insertion of electrodes of a cochlear implant.