A novel diagnostic method for myasthenia gravis.

INTRODUCTION/AIMS: Videonystagmography (VNG) which directly records eye movements using infrared video goggles with mini-cameras, is used to measure nystagmus. Our aim is to explore whether VNG can be used to detect a decrement in the extraocular muscle (EOM) activity of patients with myasthenia gravis (MG). METHODS: Thirty-four patients with MG, including 13 with ocular-predominant and 21 with generalized MG, and 23 healthy controls participated. Using VNG we recorded the velocity of the eye movements of the patients as they followed a moving target. We then calculated the gain by dividing the eye movement velocity (degrees/second) by the target velocity (degrees/second). RESULTS: In MG subjects, the mean initial gain (maximum gain) was 1.23 ± 0.31 (range: 0.63-2.15) for the right eye and 1.22 ± 0.37 (range; 0.60-2.28) for the left eye. The mean minimum gain was 0.11 ± 0.12 (0.01-0.58) for the right and 0.14 ± 0.5 (0.02-0.55) for the left. Due to fatigue, the movement gain was reduced by 91.7% in the right eye and 88.2% in the left eye. After reaching minimum velocity, gain remained at a minimum for a mean of 1.08 ± 0.52 (0.3-2.4) s for the right and 1.49 ± 0.85 (0.4-3.6) s for the left, before the velocity increased again. There was no fatigue-induced decrement in healthy subjects. DISCUSSION: Our study documents a decrement in EOM activity recorded by VNG in patients with MG which begins to improve within 1-2 s after reaching minimum velocity, analogous to traditional low-frequency repetitive nerve stimulation testing and its U-shaped pattern. Thus, VNG may be a promising diagnostic test for MG.

Extra-Cochlear Insertion in Cochlear Implantation: A Potentially Disastrous Condition.

OBJECTIVES: Cochlear implantation is an increasingly used technique for auditory rehabilitation of pediatric and adult population. Safe implantation is achieved in most cases; however, intraoperative complications and misplacement of the electrode are observed in some. The aim of this presentation was to review the characteristics of patients with extra-cochlear electrode insertion, postoperative diagnostic methods, and considerations in revision surgery. MATERIALS AND METHODS: In total, 423 cases of cochlear implantation performed in our clinic between 2012 and 2018 were retrospectively analyzed and those of extra-cochlear implantation were evaluated. RESULTS: Extra-cochlear insertion was found in 3 patients. The electrode was placed into the internal acoustic canal in the first case, superior semicircular canal in the second case, and internal carotid artery canal in the third case. Cochlear insertion was achieved in all cases with re-implantation, and no complication was observed. CONCLUSION: This case series highlights that rare, but potentially serious, consequences of misplacement of the electrode in cochlear implantation can be successfully avoided and treated via a multidisciplinary approach.

Ototoxicity associated with topical administration of diclofenac sodium as an otic drop: An experimental animal study.

OBJECTIVES: The aim of the study is to evaluate the ototoxicity of topical diclofenac sodium in comparison to positive and negative controls prior to the investigation of analgesic and anti-inflammatory efficacy of the agent in otic administration. METHODS: Twenty four ears of 12 guinea pigs were included in the study. Wide myringotomy was performed on all tympanic membranes under general anesthesia and auditory brainstem responses (ABR) were evaluated. The subjects were separated into four groups, two groups received diclofenac sodium at low and high doses, positive controls received gentamicin and negative controls received isotonic sodium chloride topically for 14 days and ABRs were reevaluated. RESULTS: No significant difference were observed between the pre and post-treatment click response, 1 kHz and 8 kHz response threshold levels after isotonic sodium chloride administration. All threshold levels were elevated in the positive control group. In the low and high dose diclofenac sodium groups, click response, 1 kHz and 8 kHz response threshold levels were significantly higher compared to the baseline values. Pre and post-treatment mean threshold level changes were not significantly different between the low and high dose diclofenac sodium groups. Pre and post-treatment mean threshold level changes in the gentamicin group were not significantly different from low or high dose diclofenac sodium groups. CONCLUSION: Diclofenac sodium, considered as an analgesic and anti-inflammatory otic preparation, is shown to be as ototoxic as gentamicin in chronic use which may lead to loss of hearing especially when used topically in chronic otitis cases with tympanic membrane damage.

Assessment of early language development in Turkish children with a cochlear implant using the TEDIL test.

OBJECTIVES: To analyse language development of children with a cochlear implant (CI) in relation to length of CI use and age at implantation and to examine the suitability of the TEDIL as an assessment tool for measuring early language development in Turkish children. METHODS: A total of 119 children implanted with a CI before 5 years of age were assessed acutely on sound field thresholds, speech recognition thresholds, open-set and closed-set monosyllabic word tests, the TEDIL, categories of auditory performance (CAP), and speech intelligibility rating (SIR). The outcome scores were analysed in relation to length of CI use (3, 4, and 5 years) and age at implantation (<24 months vs. >24 months). The TEDIL scores were compared to all other outcome measures. RESULTS: Scores significantly increased with CI experience. CAP and SIR were significantly higher in the younger implanted group. No significant difference was observed between the younger and older implanted group on the closed-set and open-set monosyllabic tests and the TEDIL. The TEDIL scores significantly correlated with CAP, SIR, and the closed-set and open-set word scores. The mean TEDIL standard score was close to average. CONCLUSIONS: Performance of CI users improves with increased CI experience. CI users implanted <24 months tend to have better auditory skills and clearer speech than CI users implanted >24 months. CI users implanted between 24 months and 60 months tend to develop language similarly to CI users implanted <24 months. The TEDIL is a suitable tool for assessing early receptive and expressive language development in Turkish children.

Safety and Efficacy of Chitosan-Dextran Hydrogel in the Middle Ear in an Animal Model.

OBJECTIVES: To investigate the efficacy of chitosan-dextran hydrogel (CDH) in preventing postoperative adhesions between the tympanic membrane (TM) and intratympanic structures, and to evaluate its ototoxicity in an animal study. METHODS: In the first step, ototoxicity was evaluated with 7 male albino guinea pigs (GPs) via auditory brainstem responses (ABR) before and 4 weeks after unilateral intratympanic injection of CDH and saline solution contralaterally. In the second step, 12 GPs underwent bilateral ear surgery. The middle ear (ME) mucosa was abraded, and the cavity was filled with CDH on one side and packed with Gelfoam on the contralateral side. A control group of 6 GPs underwent the same procedure except that no material was applied in the ME. The animals were euthanized at the end of the 7th week, and otomicroscopic findings were noted and the temporal bones harvested for the histologic examination. The findings were scored and compared. RESULTS: There was no statistically significant difference between the pre- and postoperative ABR thresholds. In the otomicroscopic findings, the most prominent difference between the two groups was the presence of retraction of the TM in the Gelfoam group. The histopathologic findings revealed a higher degree of inflammation in the Gelfoam group compared with the CDH group. CONCLUSION: This study demonstrated that CDH has no ototoxic effects in GPs. Its use as an ME packing material revealed significantly less TM retraction and inflammatory reaction compared with Gelfoam.