Book Review: Atlas of Cavityless Cholesteatoma Surgery: Vol I by K.P. Morwani, Madhuri Mehta No abstract available

Non-contrast Magnetic Resonance Imaging for Diagnosis and Monitoring of Vestibular Schwannomas: A Systematic Review and Meta-analysis Objective: This study aimed to evaluate the diagnostic accuracy of high-resolution T2-weighted magnetic resonance imaging (T2wi) in terms of detecting vestibular schwannoma compared with gadolinium-enhanced T1-weighted MRI (GdT1wi). Data Sources: Five databases (PubMed, SCOPUS, Embase, the Web of Science, and the Cochrane database). Data Selection: Two authors independently searched five databases up to January 2019 on diagnosis of vestibular schwannomas via T2wi. Data Extraction: In the included studies, tumor diameters reported using T2wi were compared with those revealed by GdT1wi and correlation coefficients were calculated. Data on true-positives, true-negatives, false-positives, and false-negatives were extracted from the relevant articles. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Inter-rater agreement among different observers and intra-rater agreement among different measurements made by a single observer was assessed. Data Synthesis: Outcomes subjected to analysis included diagnostic accuracy (the diagnostic odds ratio); summary receiver operating characteristic curve and area under the curve values. The summary intra-class correlation coefficient was used for various random-effects models. The quality of each study was analyzed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Conclusions: T2wi performed without the use of a contrast agent is a highly accurate diagnostic and monitor tool compared with GdT1wi and also demonstrated high reliability. However, further studies are required to confirm the results of this study.

Reducing Artifacts in Intracochlear Pressure Measurements to Study Sound Transmission by Bone Conduction Stimulation in Humans Hypothesis: Intracochlear pressure (ICP) measurements during bone conduction (BC) stimulation may be affected by motion of the pressure sensor relative to the cochlear promontory bone, demonstrating the need to cement the sensor firmly to the cochlear bone. Background: ICP is a promising measurement tool for investigating the cochlear drive in BC transmission, but its use is not yet standardized. Previous ICP studies have reported artificially increased pressure due to motion of the sensor relative to the temporal bone. The artifact can be reduced by firmly cementing the sensor to the bone, but this is destructive for the sensor. Previous studies used a custom-made sensor; the use of commercially available sensors, however, is more generic, but also more challenging to combine with the cement. Therefore, the goals of the current study are: firstly, to evaluate a non-destructive cementing method suitable for a commercially available sensor, and secondly, to investigate ICP measurements during BC stimulation in more detail. Methods: To study the effect of sensor cementing, three fixation conditions were investigated on six fresh-frozen temporal bones: 1) alginate, 2) alginate and dental composite, 3) alginate and dental composite, released from micromanipulators. Pressures in scala tympani and vestibuli were measured simultaneously, while velocity measurements were performed on the cochlear promontory and sensor. The ratio between sensor and promontory bone velocity was computed to quantify the relative motion. Results: For air conduction stimulation, results were in line with those from previous ICP studies, indicating that baseline measurements were valid and could be used to interpret the results obtained with BC stimulation. Results showed that cementing the sensors and releasing them from the micromanipulators is crucial for valid ICP measurements. When the sensors were only sealed with alginate, the pressure was overestimated, especially at low and mid-frequencies. When the sensors were cemented and held in the micromanipulators, the pressure was underestimated. Compared with the scala tympani measurements, ICP measurements showed a lower scala vestibuli pressure below 1 kHz, and a higher pressure above 1 kHz. Conclusion: Dental composite is effective as a cement to attach commercially available sensors to the cochlear promontory bone. When sensors are firmly attached, valid ICP measurements can be obtained with BC stimulation.

An Exploratory Study on the Use of Event-Related Potentials as an Objective Measure of Auditory Processing and Therapy Effect in Patients With Tinnitus: A Transcranial Direct Current Stimulation Study Objective: Treatment effect in tinnitus research is commonly evaluated by use of self-report questionnaires. As this is a solely subjective assessment method, the need for an objective measurement is paramount to genuinely evaluate the effects of therapeutic interventions. The current study explores the value of event-related potentials (ERPs) in the evaluation of high-definition transcranial direct current stimulation (HD-tDCS) for tinnitus treatment. Study Design: Prospective exploratory study. Setting: Tertiary referral center. Patients: Twenty-two chronic tinnitus patients. Intervention: HD-tDCS. Main Outcome Measures: ERPs. Results: The results show a significant shortening of the N1, P2, N2, and P3 latencies after HD-tDCS treatment. Moreover, the increased amplitude of the P2 and N2 peaks result in more salient and clear peaks, with the amplitude of N2 being significant larger after HD-tDCS. However, the ERP changes are not significantly correlated with the change in tinnitus functional index (TFI) total score. Conclusions: The current study was the first to explore ERPs as objective measure in a study with HD-tDCS in tinnitus patients. Adding ERPs to the outcome measures in tinnitus research may lead to a better understanding of the therapeutic effect in the future. The results showed a shortening of ERP latencies and an increased N2 amplitude, possibly reflecting more effective sound processing with higher recruitment of synchronized neurons in the auditory cortex. Future studies should elaborate on these results, by collecting control data and adding a sham group, to provide a better insight in the underlying mechanism of the ERP changes after tinnitus treatment.

Cognitive Performance in Chronic Tinnitus Patients: A Cross-Sectional Study Using the RBANS-H Objective: Many tinnitus patients report cognitive deficits such as concentration and attention difficulties. The aim of this study was to comprehensively assess cognitive functioning in tinnitus patients using a standardized test battery, the repeatable battery for the assessment of neuropsychological status adjusted for hearing impaired individuals (RBANS-H). Study Design: Cross-sectional study. Setting: Tertiary referral center. Participants: Twenty-eight chronic tinnitus patients and 28 control participants, matched for sex, age, hearing loss, and education level. Intervention: Diagnostic. Main Outcome Measures: All participants completed the RBANS-H, which includes subtests probing immediate and delayed memory, visuospatial capabilities, language, and attention. The tinnitus patients completed the tinnitus functional index (TFI), a visual analogue scale (VAS) measuring subjective mean tinnitus loudness and the hyperacusis questionnaire (HQ). Results: The total RBANS-H scores did not differ between tinnitus patients and controls. However, on the language subscale, mean scores of the tinnitus group (97.6 ± 11.0) were significantly lower than those of controls (104.4 ± 12.0), with correction for sex, age, hearing level, and education level (general linear model: p = 0.034). Post hoc t tests revealed a specific deficit concerning the semantic fluency subtest (tinnitus: 19.5 ± 6.2; control: 23.1 ± 5.9; p = 0.015). VAS scores for tinnitus loudness were negatively correlated to scores on the RBANS-H attention subscale (r = –0.48, p = 0.012). Conclusions: The current study successfully employed the RBANS-H to provide a broader view on cognitive functioning in tinnitus patients. The results showed a specific negative influence of tinnitus on verbal fluency, which could be related to a deficit in executive cognitive control. Moreover, patients experiencing louder tinnitus performed worse on specific subtests concerning attention.

Neuropathological Findings of Dementia Associated With Subjective Hearing Loss Objective: The relationship between hearing loss and cognitive decline is of great importance with growing evidence of hearing loss as an independent modifiable risk factor for dementia. Our goal was to evaluate for differences in dementia neuropathology between subjective normal hearing and hearing loss subjects, as well as subjects who wore hearing aids. Study Design: Retrospective database. Setting: Tertiary academic center. Patients: Brain tissue analyzed from our Center on Aging. Demographics, subjective hearing status, hearing aid use, cognitive status, and dementia neuropathology documented. Interventions: Dementia neuropathology analyzed in brains of normal hearing and hearing loss subjects. Main Outcome Measures: Differences in dementia neuropathology between hearing groups. Groups were compared using logistic regression and analysis of covariance (ANCOVA). Results: Two-hundred and seventy-three subjects were included, 189 normal hearing and 84 subjective hearing loss subjects. No significant difference demonstrated in Alzheimer's disease neuropathology (p > 0.05) or pathologic stage (p = 0.2471). No significant difference observed in neuropathology of other major dementia types, specifically, presence of Lewy bodies (p > 0.05), Lewy body disease pathologic stage (p = 0.9778), or presence of micro-infarcts, macro-infarcts, or arteriosclerosis (p > 0.05). Hearing aid-wearing subjects had a lower prevalence of clinical dementia (39.1% versus 57.9%; p = 0.0208) with no significant difference in dementia neuropathology (p > 0.05). Conclusion: Subjective hearing loss was not found to be associated with significantly different dementia neuropathology, which counters hypotheses on hearing loss causing permanent neurodegeneration and cognitive decline. Hearing aid users were found to have a lower prevalence of dementia for similar levels of neurodegeneration, suggesting a potential neuroprotective effect of hearing aids.

High Dose of Intratympanic Steroids for Sudden Sensorineural Hearing Loss Salvage Objective: Intratympanic (IT) steroid administration for sudden sensorineural hearing loss is offered as salvage to patients who failed systemic steroid treatment. Our objective was to study the audiometric and clinical outcomes of patients given salvage therapy with high-dose IT steroids instilled via ventilation tube. Study Design: Retrospective case review. Setting: Academic secondary medical center. Patients: One hundred three patients >18 years of age with sudden sensorineural hearing loss who failed systemic steroids and received IT treatment between 2010 and 2018. Intervention: Following ventilation tube insertion, 1 ml of 10 mg/ml dexamethasone was instilled, twice daily, for 7 days. Outcome Measures: Hearing assessment immediately before and after treatment. Tinnitus and vertigo complaints and risk factors were also retrieved. Results: Tinnitus had improved in 53 (52%) patients, vertigo in 4 (4%), and aural fullness sensation in 56 (55%) (p < 0.001, p = 0.344, p < 0.001, respectively). The mean pure-tone threshold difference across frequencies following treatment was between 0 and 6 dB. A significant improvement was observed at 250, 500, 1000 Hz (p < 0.001 in all), and at 2000 Hz (p = 0.035). No significant difference was found at 4000 and 8000 Hz (p = 0.055, p = 0.983 respectively). Mean pure-tone average improvement of 4.5 dB was detected in 61 (59%) patients (p = 0.001). The mean speech discrimination score improved by 7% (p = 0.001). Four (22%) diabetic and nine (20%) hypertensive patients had pure-tone average ≥10 dB improvement (p = 0.759, p = 0.852 respectively). Conclusion: Although more than half of the patients improved clinically, the significance of the slight audiometric improvement should be weighed against the treatment protocol's complications.

Early Magnetic Resonance Imaging for Patients With Idiopathic Sudden Sensorineural Hearing Loss in an Emergency Setting Objective: The role of magnetic resonance (MR) imaging in idiopathic sudden sensorineural hearing loss (ISSHL) is controversial due to the inhomogeneity of clinical and MR protocols. The aim of this work is to relate early MR findings obtained immediately after the admission, with the clinical presentation, the audiological findings, and the outcomes of treatment. Study Design: Prospective observational study. Setting: Tertiary referral university center. Patients: Forty-seven patients (22 M, 25 F; age: 54.4 ± 17.5 yr) consecutively referred to the Department of Emergency for ISSHL. Interventions: All patients underwent the diagnostic and therapeutic work-up for ISSHL, and MR imaging within 72 hours from the admission, independently of the symptoms onset. All patients received the same treatment (systemic steroid therapy, intratympanic steroid injection, and hyperbaric oxygen therapy). Main Outcome Measure(s): MR patterns, clinical, and laboratory findings. Results: MR imaging was positive in 25 of 47 cases (53%), with a perfect agreement between clinical and MR examinations (Cohen K = 1) upon the affected ear. Three different radiological patterns were observed: labyrinthine haemorrhage (n = 5), acute inflammatory process (n = 14), isolated blood–labyrinth barrier breakdown (n = 6). By binary logistic regression, only vertigo was associated with a positive MR imaging [B = 2.8; p = 0.011; OR = 9.5 (95% CI: 2.2–40.8)] and the latter was the only variable associated with an unfavorable outcome [(B = 2.8; p = 0.02 OR = 12.8 (95% CI: 2.9–56.7)]. Conclusion: Patients affected by ISSHL with associated vertigo show a higher likelihood of having a positive MR imaging, which, in turn, seems to predict an unfavorable outcome.

Factors Influencing Pediatric Cochlear Implant Outcomes: Carolina Sibling Study Objective: To determine the correlation between speech perception performance between pediatric sibling pairs with severe to profound sensory hearing loss receiving cochlear implants, and in cases of discordance in performance, determine which variables negatively impacted performance. Study Design: Retrospective chart review. Setting: Tertiary academic referral center. Subjects: Eighty-nine pediatric subjects, 43 sibling groups, under the age of 18 with severe to profound sensory hearing loss who received a cochlear implant with a sibling who also received a cochlear implant. Intervention: Cochlear implantation. Main Outcome Measures: Speech perception scores, consonant-nucleus- consonant score. Results: A statistically significant correlation was found between speech perception performance of pediatric siblings. Depth of insertion is positively correlated with better speech perception in siblings with discordant results. There was no significant relationship with either electrode type, unilateral/bilateral status, or age of implantation. Conclusion: Pediatric siblings have a high correlation in speech perception outcomes following cochlear implantation, suggesting family environment plays a strong role. In circumstances in which outcomes between siblings are substantially different, greater depth of implant insertion is correlated with better consonant-nucleus- consonant word scores.

Hearing Preservation With the Use of Flex20 and Flex24 Electrodes in Patients With Partial Deafness Objective: To evaluate the impact of electrode length on hearing preservation (HP) in Partial Deafness Treatment–Electrical Complement (PDT-EC) subjects. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Twenty-three PDT-EC patients (with preoperative air-conduction thresholds ≤30 dB up to 500 Hz) were divided into two groups: Flex20 electrode (Med-EL GmbH, Innsbruck, Austria) (12 patients) and Flex24 electrode (Med-EL GmbH, Innsbruck, Austria) (11 patients). Interventions: All participants were subjected to minimally invasive cochlear implantation using the round window approach. Main Outcome Measure(s): Pure tone audiometry (125–8000 Hz) was performed preoperatively and at 1, 6, 12, and 24 months postoperatively. HP was established using the HEARRING group formula. Speech understanding was assessed preoperatively and at 12 and 24 months postoperatively. Results: Analysis of HP for every individual indicates that more than half the patients with Flex20 and Flex24 had complete HP at 6 months follow-up. None of the patients from either group had complete loss of hearing. At activation, average air-conduction thresholds for low frequencies (125–500 Hz) were slightly better for the short electrode (M = 29.03) than for the long (M = 39.10) but the difference was not statistically significant (p = 0.067). The effect of electrode (Flex20 versus Flex24) was not significant in terms of pure tone audiometry and speech recognition at long-term follow-up. Conclusions: In the early postoperative period, complete HP was possible in a majority of patients from both groups, but slightly better HP outcomes were achieved by Flex20. In the long term, the length of the electrodes does not affect the degree of HP or speech understanding.