Ahmed Khater

Methods of Hearing Preservation during Cochlear Implantation

Introduction  Recent advances in surgical techniques and electrode design have made residual hearing preservation during cochlear implantation (CI) possible, achievable, and desirable. Objectives  The objective of this study was to review the literature regarding methods used for hearing preservation during CI surgery. Data Synthesis  We performed a search in the LILACS, MEDLINE, SciELO, PubMed databases, and Cochrane Library, using the keywords CI, hearing preservation, CI electrode design, and CI soft surgery. We fully read about 15 studies that met the criteria described in “study selection”. The studies showed that several factors could contribute to possible cochlear damage during or after CI surgery and must be kept in mind; mechanical damage during electrode insertion, shock waves in the perilymph fluid due to implantation, acoustic trauma due to drilling, loss of perilymph and disruption of inner ear fluid homeostasis, potential bacterial infection, and secondary intracochlear fibrous tissue formation. The desire to preserve residual hearing has led to the development of the soft-surgery protocols with its various components; avoiding entry of blood into the cochlea and the use of hyaluronate seem to be reasonably supported, whereas the use of topical steroids is questionable. The site of entry into the cochlea, electrode design, and the depth of insertion are also important contributing factors. Conclusion  Hearing preservation would be useful for CI patients to benefit from the residual low frequency, as well as for the children who could be candidate for future regenerative hair cell therapy.

An evidence-based guide for intraoperative cochlear implant backup use.

OBJECTIVES Intraoperative assessment of electrode function and position is essential for cochlear implant outcomes. Electrophysiological measures and radiographic imaging modalities have been used for this purpose. This study was conducted to determine the relative utility of X-ray, impedance measurements and ECAP for cochlear implant function. METHODS A retrospective review was conducted for 132 children (age range from 5 to 13 years old) who underwent cochlear implantation. 3 months after switch on, aided free field (FF) and Ling Six Sounds were compared between patients who had intraoperative ECAP and those who had not intraoperative ECAP (but with normally located electrode array as confirmed by plain X-ray). RESULTS Only 4 cases (3%) had abnormal impedance measurements that became normal after reinsertion of the same electrode array. 3 cases (2.3%) showed malposition of the electrode array on plain radiograph. They underwent immediate revision. 11 cases (8.3%) had absent intraoperative ECAP response for all electrodes, and 4 cases (3%) had absent intraoperative ECAP response for basal electrodes. These devices were not explanted at the time of surgery. 3 months after switch on, FF and the ling 6 sounds were tested for all patients. No statistical significant differences were found between cases with normal intraoperative ECAP and those who gave no response in ECAP. CONCLUSION From the study we can conclude that plain X-ray is the guideline for backup use. Results of plain X-ray impacted surgical decision making and led to the use of the backup device. In patients with correct electrode placement in normally developed cochlea as detected by X-ray, it is not recommended to use the backup even if there is no intraoperative ECAP. Also, it is recommended to follow how those children performed after 1 or 2 years to see if making the decision of using or not a backup device based in electrophysiology measures vs X-ray made a difference.

Sudden Sensorineural Hearing Loss: Comparative Study of Different Treatment Modalities

Introduction  Idiopathic sudden sensorineural hearing loss (ISSNHL) is hearing loss of at least 30 dB in at least 3 contiguous frequencies within at least 72 hours. There are many different theories to explain it, and many different modalities are used for its management, such as: systemic steroids (SSs), intratympanic steroid injection (ITSI), hyperbaric oxygen therapy (HOT), antiviral drugs, and vasodilators or vasoactive substances. Objectives  This study aims to evaluate the efficacy of the combination of the most common treatment modalities of ISSNHL and to compare the results if HOT was not one of the treatment modalities administered. Methods  The study was conducted with 22 ISSNHL patients with ages ranging from 34 to 58 years. The patients were divided into 2 groups; group A included 11 patients managed by SSs, ITSI, antiviral therapy, and HOT simultaneously, and group B included 11 patients exposed to the aforementioned modalities, with the exception of HOT. Results  After one month, all of the patients in group A showed total improvement in hearing in all frequencies, with pure tone average (PTA) of 18.1 ± 2.2, while in group B, 5/11 (45.5%) patients showed total improvement, and 6 /11 (54.5%) patients showed partial improvement, with a total mean PTA of 28.1 ± 8.7. Conclusion  The early administration of HOT in combination with other clinically approved modalities (SSs, ITSI, antiviral therapy) provides better results than the administration of the same modalities, with the exception of HOT, in the treatment of ISSNHL.

Bilateral vestibulopathy treatment: Update and future directions

Bilateral vestibulopathy or BVH is a disorder of both labyrinths and/or vestibular nerves which have various etiologies. BVH is most often a chronic condition in which patients can suffer from blurred vision (oscillopsia), impaired spatial orientation and postural instability. Moreover, there is no continuing distressing vertigo, spontaneous nystagmus, or postural falls, which are typical signs of a vestibular tone imbalance caused by acute unilateral lesions. Those symptoms lead to an important decrease in physical activity, social functioning and vitality that dramatically impact the patients′ quality of life. The treatment options for various forms of BVH could be one of the following four lines of treatment: (a) Preventive treatment through prevention of ototoxicity, (b) therapeutic treatment through medical treatment of the causative underlying disease, (c) rehabilitative treatment through the vestibular rehabilitation therapy, (d) future directions through sensory substitution devices (balance prostheses technology). The prognosis of BVH is poor and more than 80% of the patients do not improve. The aim of this study was to discuss the update and the future directions in the treatment of the bilateral vestibular hypofunction (BVH).

Effect of central inset pharyngeal flap for velopharyngeal insufficiency on eustachian tube function.

The aim of this study was to assess the effect of the central inset pharyngeal flap, used for correcting persistent velopharyngeal incompetence after cleft palate repair, on Eustachian tube (ET) function.

Contralateral Bimodal Stimulation: A Way to Enhance Speech Performance in Arabic-Speaking Cochlear Implant Patients

Background: The combination of acoustic and electric stimulation as a way to enhance speech recognition performance in cochlear implant (CI) users has generated considerable interest in the recent years. The purpose of this study was to evaluate the bimodal advantage of the FS4 speech processing strategy in combination with hearing aids (HA) as a means to improve low-frequency resolution in CI patients. Methods: Nineteen postlingual CI adults were selected to participate in this study. All patients wore implants on one side and HA on the contralateral side with residual hearing. Monosyllabic word recognition, speech in noise, and emotion and talker identification were assessed using CI with fine structure processing/FS4 and high-definition continuous interleaved sampling strategies, HA alone, and a combination of CI and HA. Results: The bimodal stimulation showed improvement in speech performance and emotion identification for the question/statement/order tasks, which was statistically significant compared to patients with CI alone, but there were no significant statistical differences in intragender talker discrimination and emotion identification for the happy/angry/neutral tasks. The poorest performance was obtained with HA only, and it was statistically significant compared to the other modalities. Conclusion: The bimodal stimulation showed enhanced speech performance in CI patients, and it improves the limitations provided by electric or acoustic stimulation alone.

Improvement of cochlear implant performance: changes in dynamic range

Context Theoretically, a wide input dynamic range (IDR) will capture more of the incoming acoustic signal than a narrow IDR, allowing the cochlear implant (CI) user to hear soft, medium, and loud sound. A narrow IDR may restrict the CI user′s ability to hear soft speech and sound because less of the incoming acoustic signal is being mapped into the CI user′s electrical dynamic range. Aim The overall goal of the study is to provide guidelines for audiologists to efficiently and effectively optimize performance of CI recipients for two difficult listening situations: understanding soft speech and speech in noise. Settings and design Two variables were studied; the independent variables were IDR and the electric dynamic range of the channels. The dependent variables were six Ling sounds, monosyllabic word test, and speech in noise test. Materials and methods Fourteen patients participated in the study. For each patient, seven programs were created. In each program, dependent variables were assessed in different independent ones. Results A restricted IDR resulted in poor speech recognition compared with the relatively wide IDR. Subjectively determined T level and most comfortable level (MCL) at the most, not the maximum, comfortable level appears to have a positive effect on both soft sound recognition and speech discrimination. Conclusion Dynamic range is an important factor -among others- to improve the ability of CI users to understand soft speech as well as speech in noise.

Horizontal and Vertical vHIT in Acute Unilateral Vestibular Neuritis Patients

Objectives : Vestibular neuritis (VN) is an acute peripheral vestibulopathy that manifests with acute spontaneous vertigo, nausea and sometimes vomiting, and postural imbalance. Video head impulse test (vHIT) is an objective measure of responses of semicircular canals using high speed video measures of eye movement response to head impulses. The purpose of this study was to measure and analyze horizontal and vertical vestibular canals responses measured by vHIT in acute unilateral VN and to compare the results with the un-affected sides in those patients. Design : The responses of vHIT were obtained from 31 patients with acute VN (16 females and 15 males) ranging in age from 24 to 54 years. Audiological and vestibular assessments were done to all participants that include pure tone, speech audiometry, tympanometry, acoustic reflexes, vestibular bed side evaluation and caloric testing. Results : The mean age of VN patients were 38.03 ± 7.96 years. The right side was affected in 14 and left in 17 patients. The gain of vHIT was reduced in the affected side of VN which was statistically significant when compared with the un-affected side. Isolated horizontal canal was observed in 15 patients whereas mixed horizontal and vertical canals were observed in 9 patients. Vertical canals were affected in 7 out of 31 patients. Discussion and Conclusion : Acute VN patients do have single or multi-semicircular canals affection which can be objectively measured for each canal by vHIT. The lesion is manifested by reduction in amplitude response for affected canal which can affect the superior division mainly and to less extent the inferior vestibular division.

Audiological findings in children with chronic renal failure on regular hemodialysis

Background The nephron in the kidney and the stria vascularis in the inner ear have many anatomical, physiological, and pathological similarities. Several studies have reported sensorineural hearing loss in adult chronic renal failure (CRF). However, there are only a few reported surveys on audiological affection in children with CRF. Objectives The aim of this study was to determine the presence, type, and severity of hearing loss (HL) and to evaluate the relationship of reported HL with the duration of hemodialysis and biochemical and hematological data of children with CRF on regular hemodialysis. Patients and methods This study included 30 patients with CRF on regular hemodialysis and 20 healthy children as a control group. All children were subjected to standard and extended high-frequency pure-tone audiometry, tympanometry, and otoacoustic emissions. Results Among 60 ears examined, 50 ears showed sensorineural hearing loss (83.3%), mainly at high frequencies (64%) and of mild and moderate severity, with a highly statistically significant difference between pure-tone thresholds in the patients and the control groups across frequencies 500–8000 Hz. High-frequency thresholds were significantly higher for the patients with CRF. No significant relation was found with the duration of hemodialysis or biochemical and hematological parameters. Transient-evoked otoacoustic emissions testing showed absent emission in 20 ears and those with preserved transient-evoked otoacoustic emissions had significantly lower amplitudes in all frequencies. Conclusion A high incidence of HL among children with CRF on regular hemodialysis was found in this study. Duration of hemodialysis treatment and biochemical and hematological parameters did not have a significant impact on HL. Thus, audiological evaluation must be considered in these children.