Transmastoid Superior Semicircular Canal Plugging: A Prospective Analysis of Surgical Outcomes.

OBJECTIVES: To assess the outcomes of the transmastoid superior semicircular canal plugging in patients with superior semicircular canal dehiscence (SSCD). STUDY DESIGN: Prospective cohort study. SETTING: Tertiary, university center. PATIENTS: Patients with SSCD undergoing transmastoid superior semicircular canal plugging within a 30-month period. INTERVENTIONS: Transmastoid superior semicircular canal occlusion. MAIN OUTCOME MEASURES: We documented the surgical technique, pre- and postoperative (3-month review) dizziness handicap inventory scores, average hearing thresholds, low-frequency air-bone gap, six-canal video head-impulse-test responses, improvement of the auditory symptoms and complications. RESULTS: Out of 30 patients with SSCD, 11 patients (12 ears) were enrolled with an average age 41.17 years (range 32-65 years). Oscillopsia resolved in all patients; DHI score improved from 56.7 (range 22-84) preoperatively to 25.83 (10-46) postoperatively (p = 0.001), while out of the nine patients with troublesome auditory symptoms, five patients noticed an improvement. The average pre- and postoperative hearing thresholds were 15.2 dB (range 3-32.5 dB) and 14.17 dB (range 5-30 dB) (p = 0.73), respectively. The average pre- and postoperative low-frequency air bone gap was 12.3 dB (range 5-20 dB) and 9.4 dB (range 0-20 dB), respectively (p = 0.24) (Table 1). There were no major complications; two patients developed postoperative benign paroxysmal positional vertigo. CONCLUSION: Transmastoid plugging of the superior semicircular canal can safely and significantly improve the vestibular symptoms of the patients with SCDS, as well as the auditory symptoms in a substantial number of patients in a hearing-preservation way.

Video Head Impulse Test (vHIT) Findings in Patients With Superior Semicircular Canal Dehiscence: A Case-Control Study.

OBJECTIVE: To explore the usefulness of the responses of video head impulse testing (vHIT) in assessing symptomatic patients with superior semicircular canal dehiscence (SSCD). METHODS: This was a prospective case-control study performed in a tertiary skull base referral Centre in the UK. It included all patients ¬diagnosed with SSCD from January 2015 to January 2019 and compared to a control group of age and gender-matched unaffected indi¬viduals. The main outcome of the study was semicircular canal vestibule-ocular reflex (VOR) gains during vHIT assessment and link to patients' symptoms. RESULTS: A total of 28 patients were diagnosed with SSCD during the study period and completed the vHIT assessment. Reduced VOR gains (<0.8) were noted in 57% of patients (n = 16). Half of these (n = 8) were in canals other than the superior semicircular (posterior only: n = 5; lateral and posterior: n = 3). Three patients (10.7%) had abnormal responses in 2 canals. The canals in the contralateral side were affected in 56.5% of the cases. There was no correlation with the patients' symptoms. Results were directly comparable with the control group vHIT results with no identifiable statistically significant differences on comparison of the ipsilateral SSCD side with a randomly selected side from the control group (all comparisons: P > .05). CONCLUSION: SSCD can affect the vestibular responses from all 3 semicircular canals; not necessarily the superior one. Similar responses were found in a control group of normal subjects. Although the use of vHIT in the assessment of SSCD is not diagnosis-specific, it can still help with identifying the impact of surgery on all canals prior to any intervention in order to avoid bilateral vestibular failure.

Intratympanic Gentamicin Versus Labyrinthectomy: Inner Ear Sensitivity to Gentamicin and Impact on the Contralateral Labyrinth.

OBJECTIVES: To investigate the impact of labyrinthectomy and intratympanic (IT) gentamicin injections on the contralateral labyrinth, we also assessed the response of each individual semicircular canal to each IT gentamicin application. METHODS: We performed a pilot observational study on tertiary, referral, academic settings. Thirteen patients with unilateral vestibular pathology were organized into two groups, group I (seven patients) receiving IT gentamicin and group II undergoing labyrinthectomy (six patients). All patients underwent six-canal video-head-impulse test in predetermined time intervals. Patients receiving gentamicin were additionally tested 3 to 5 days after every sequential injection, until all ipsilateral canals were ablated, to determine the order of response to gentamicin. We recorded the vestibular-ocular reflex gains and the presence of covert/overt saccades for each canal. RESULTS: The posttreatment ipsilateral gains were abnormal. No patient from the gentamicin group developed abnormal contralateral responses, while patients undergoing labyrinthectomy had abnormal contralateral responses from at least one canal, even several months posttreatment. Finally, the lateral semicircular canal was the first one to be affected by IT gentamicin followed by the posterior canal: the superior canal was ablated last. CONCLUSION: In our study, labyrinthectomy had an impact on the responses recorded from the contralateral ear, while IT gentamicin ablated the ipsilateral labyrinthine function without affecting the contralateral responses, possibly because of a milder, more gradual impact. We also show for the first time the order that IT gentamicin application affects the semicircular canals, with the lateral being the first to be affected.

Ménière's Disease and Underlying Medical and Mental Conditions: Towards Factors Contributing to the Disease.

PURPOSE OF THE STUDY: To investigate the relation of Ménière's disease (MD) with medical comorbidity or mental conditions. PROCEDURES: Demographic data, medical and mental comorbidities were retrospectively collected and compared from 3 groups of 30 patients each: a group with patients with definite MD, a second one with patients with vestibulopathies other than MD (non-Ménière's vertigo, NMV) and a third one with patients without any vestibular symptoms (control). The level of significance was set at 0.05. RESULTS: The prevalence of mental conditions was 26.7, 23.3 and 6.7% for the MD, the NMV and the control group, respectively. Medical comorbidity was found in 80% of patients in the MD, 63% in the NMV and 20% in the control group. Arthritis was encountered in 8 patients with MD, 3 with NMV and none from the control group. The differences in prevalence of mental disease, comorbidities and arthritis between the MD and the control group were statistically significant (p = 0.02, p < 0.001 and p = 0.008, respectively). CONCLUSION: Psychological conditions play an important role in patients with MD. The significantly increased prevalence of arthritis in the MD group suggests an inflammatory/autoimmune background as a contributing factor to the disease.