Evolution of Cochlear implant mapping and vestibular function in a pediatric case of Labyrinthitis

The role of vestibular function tests in nontuberculous mycobacterial otomastoiditis: A case report

BACKGROUND

Nontuberculous mycobacteria (NTM), an extremely rare pathogen causing cervicofacial infections, may result in permanent hearing impairment or intracranial complications. Due to the lack of specific manifestations during the initial onset of NTM otomastoiditis, physicians may misdiagnose it as cholesteatoma or other common bacterial infections.

PATIENT CONCERNS

A 44-year-old male who complained of left-sided aural fullness, otalgia, and dizziness for 2 months.

DIAGNOSIS

The initial diagnosis was hypothesized to be cholesteatoma based on a whitish mass with mucoid discharge filling the entire outer ear canal on otoscopy and left-sided mixed hearing loss. However, NTM was identified by microbial culture at the 2-month follow-up after surgery.

INTERVENTIONS

The patient underwent a left-sided exploratory tympanotomy. Because NTM otomastoiditis was diagnosed, 3 weeks of starting therapies were administered with azithromycin (500 mg/day, oral administration), cefoxitin (3 g/day, intravenous drip), and amikacin (750 mg/day, intravenous drip). The maintenance therapies were azithromycin (500 mg/day, oral administration) and doxycycline (200 mg/day, oral administration) for 7 months.

OUTCOMES

The patient's clinical condition improved initially after surgery, but the otomastoiditis gradually worsened, combined with subtle meningitis, 2 months after surgery. The external auditory canal became swollen and obstructed, making it difficult to monitor the treatment efficacy through otoscopy. Thus, we used regular vestibular function tests, including static posturography, cervical vestibular evoked myogenic potentials, and video Head Impulse Test, to assess recovery outcomes. After antibiotic treatment, the infectious symptoms subsided significantly, and there was no evidence of infection recurrence 7 months after treatment. Improvements in static posturography and cervical vestibular evoked myogenic potentials were compatible with the clinical manifestations, but video Head Impulse Test showed an unremarkable correlation.

LESSONS

The clinical condition of NTM otomastoiditis may be evaluated using vestibular tests if patients have symptoms of dizziness.

Vertigo Associated With Cochlear Implant Surgery: Correlation With Vertigo Diagnostic Result, Electrode Carrier, and Insertion Angle

Objective: Vertigo is a common side effect of cochlear implant (CI) treatment. This prospective study examines the incidence of postoperative vertigo over time and aims to analyze influencing factors such as electrode design and insertion angle (IA). Study Design and Setting: This is a prospective study which has been conducted at a tertiary referral center (academic hospital). Patients: A total of 29 adults were enrolled and received a unilateral CI using one of six different electrode carriers, which were categorized into "structure-preserving" (I), "potentially structure-preserving" (II), and "not structure-preserving" (III). Intervention: Subjective vertigo was assessed by questionnaires at five different time-points before up to 6 months after surgery. The participants were divided into four groups depending on the time of the presence of vertigo before and after surgery. Preoperatively and at 6 months postoperatively, a comprehensive vertigo diagnosis consisting of Romberg test, Unterberger test, subjective visual vertical, optokinetic test, video head impulse test, and caloric irrigation test was performed. In addition, the IA was determined, and the patients were divided in two groups (<430°; ≥430°). Main Outcome Measures: The incidence of vertigo after CI surgery (group 1) was reported, as well as the correlation of subjective vertigo with electrode array categories (I-III) and IA. Results: Among the participants, 45.8% experienced new vertigo after implantation. Based on the questionnaire data, a vestibular origin was suspected in 72.7%. The results did not show a significant correlation with subjective vertigo for any of the performed tests. In group 1 with postoperative vertigo, 18% of patients showed conspicuous results in a quantitative analysis of caloric irrigation test despite the fact that the category I or II electrodes were implanted, which are suitable for structure preservation. Average IA was 404° for the overall group and 409° for group 1. There was no statistically significant correlation between IA and perceived vertigo. Conclusions: Though vertigo after CI surgery seems to be a common complication, the test battery used here could not objectify the symptoms. Further studies should clarify whether this is due to the multifactorial cause of vertigo or to the lack of sensitivity of the tests currently in use. The proof of reduced probability for vertigo when using atraumatic electrode carrier was not successful, nor was the proof of a negative influence of the insertion depth.