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Background: A vestibular implant can partially restore vestibular function by providing motion information through implanted electrodes. During vestibular implantation, various obstructions of the semicircular canals, such as protein deposits, fibrosis, and ossification, can be encountered. The objective was to explore the relationship between preoperative imaging and intraoperative findings of semicircular canal obstruction and to develop surgical strategies for dealing with obstructions of the semicircular canal(s) in patients eligible for vestibular implantation. Methods: Patients undergoing vestibulocochlear implantation (in an active clinical trial) were included in the current study when preoperative imaging indicated an obstruction in the semicircular canal. Preoperative imaging consisted of CT and MRI scans. During surgery, the bony semicircular canals were skeletonized ("bluelined") to identify the course of the canals and create a fenestration to insert the electrodes. The aim was to place the electrodes in the semicircular canal ampullae. Surgical strategies were developed to deal with the soft tissue obstructions. These procedures were evaluated intraoperatively with microscopic visualization, postoperatively with CT imaging. Results: The three included patients suffered from bilateral vestibulopathy and hearing loss due to autosomal dominant nonsyndromic sensorineural deafness 9 (DFNA9). A soft tissue obstruction was predicted in one semicircular canal (2 patients) or two semicircular canals (1 patient), based on preoperative imaging. Intraoperatively, bluelining the semicircular canals aided in identifying these locations, by revealing a "whiteline" instead of blueline. Depending on the nature and location of the obstruction, different surgical procedures were employed to facilitate proper electrode insertion. These were as follows: a dummy electrode was used to probe the soft tissue, the obstructive tissue was removed, and/or a bypass fenestration was created. In all patients, the electrodes could be implanted in the semicircular canal ampullae. Based on these first experiences, a diagnostic and surgical guide to deal with obstructions of the semicircular canals during vestibular implantation was developed. Conclusions: Preoperative imaging can indicate locations of obstructions in the SCCs. Different surgical procedures can be applied to enable appropriate electrode positioning in the SCC ampulla. This article describes the first experiences with obstructions of the semicircular canals during intralabyrinthine vestibular implantation and presents a diagnostic and surgical guide. Trial registration: ABR NL73492.068.20, METC20-087 (Maastricht University Medical Center) and NAC 11-080 (Geneva University Hospitals). [ABSTRACT FROM AUTHOR]

Introduction: The vestibular implant is a neuroprosthesis which offers a potential treatment approach for patients suffering from vestibulopathy. Investigating the influence of electrical stimulation parameters is essential to improve the vestibular implant response. Optimization of the response focuses on the electrically evoked vestibulo-ocular reflex. It aims to facilitate high peak eye velocities and adequate alignment of the eye movement responses. In this study, the basic stimulation parameters of the vestibular implant were tested for their effect on the electrically evoked vestibulo-ocular reflex. Methods: Four stimulation parameters, including the stimulation amplitude, phase duration, stimulus rate and speed of change of stimulation, were systematically tested in a cohort of nine subjects with a vestibulo-cochlear implant. These parameters were tested to evaluate their effect on fitting settings (i.e., threshold of activation, upper comfortable limit and dynamic range) as well as on the electrically evoked vestibulo-ocular reflex (peak eye velocity and alignment). Results: It was confirmed that, in addition to current amplitude, the peak eye velocity of the response can be increased by increasing the phase duration and pulse rate. Both parameters have little effect on the alignment of the eye response. However, a longer phase duration decreased the range between the threshold of activation and the upper comfortable limit of the electrical stimulation (i.e., dynamic range). Furthermore, these results show that next to the amplitude of the stimulation, the speed of change in stimulation has a determinative positive effect on the peak eye velocity. Conclusion: The observations in this study imply that the vestibular implant response, in terms of peak eye velocity, can be optimized with a higher pulse rate and longer phase duration. However, this comes at a trade-off between the dynamic range and power consumption. This study provides essential insights for fitting strategies in future vestibular implant care. [ABSTRACT FROM AUTHOR]

Background/Objectives: Chronic unilateral vestibular hypofunction (UVH) can lead to disabling vestibular symptoms and a decrease in quality of life. The aim of this study was to investigate etiologies, clinical subtypes, symptoms, and quality of life (QoL) in patients with chronic UVH. Methods: A retrospective study was performed on 251 UVH patients in a tertiary referral center. Inclusion criteria comprised reduced or absent caloric responses, with a caloric asymmetry ratio ≥25%. Patients with central vestibular pathology, symptom duration <3 months, and incomplete responses to questionnaires were excluded. Patient records were assessed for etiologies, secondary vestibular diagnoses, clinical subtypes, and questionnaires related to QoL. Additionally, multiple linear regression analysis was performed to evaluate factors influencing QoL. Results: Thirteen different etiologies were identified, with Menière's Disease as the most prevalent (31%, n = 79). The most frequently reported secondary vestibular diagnoses were benign paroxysmal positional vertigo (BPPV) (21%, n = 54) and persistent postural perceptual dizziness (PPPD) (19%, n = 47). Five distinct clinical subtypes were identified: recurrent vertigo with UVH (47%), rapidly progressive UVH (25%), idiopathic/unknown UVH (18%), slowly progressive UVH (8%), and congenital UVH (2%). Over 80% of UVH patients experienced moderate-to-severe handicap, as indicated by the Dizziness Handicap Inventory. Approximately 20–25% of UVH patients exhibited moderate-to-severe depression and anxiety, based on the Hospital Anxiety and Depression Scale. Multiple linear regression analyses demonstrated that the presence of PPPD significantly reduced QoL in chronic UVH patients. Conclusions: Chronic UVH is a heterogeneous disorder. Secondary vestibular diagnoses like BPPV and PPPD often co-exist and can significantly impact QoL. A structured diagnostic approach and tailored interventions are crucial to address the diverse needs of UVH patients. [ABSTRACT FROM AUTHOR]

Background: DFNA9 is a genetic disease of the inner ear, causing progressive bilateral sensorineural deafness and bilateral vestibulopathy (BV). In this study, DizzyQuest, a mobile vestibular diary, and the MOX accelerometer were combined to assess the daily life functional limitations and physical activity of patients with DFNA9 suffering from BV. These parameters might be appropriate as potential candidacy criteria and outcome measures for new therapeutic interventions for BV. Methods: Fifteen DFNA9 patients with BV and twelve age-matched healthy controls were included. The DizzyQuest was applied for six consecutive days, which assessed the participants' extent of functional limitations, tiredness, types of activities performed during the day, and type of activity during which the participant felt most limited. The MOX accelerometer was worn during the same six days of DizzyQuest use, measuring the participants intensity and type of physical activity. Mixed-effects linear and logistic regression analyses were performed to compare the DFNA9 patients and control group. Results: DFNA9 patients with BV felt significantly more limited in activities during the day compared to the age-matched controls, especially in social participation (p < 0.005). However, these reported limitations did not cause adjustment in the types of activities and did not reduce the intensity or type of physical activity measured with accelerometry. In addition, no relationships were found between self-reported functional limitations and physical activity. Conclusions: This study demonstrated that self-reported functional limitations are significantly higher among DFNA9 patients with BV. As a result, these limitations might be considered as part of the candidacy criteria or outcome measures for therapeutic interventions. In addition, the intensity or type of physical activity performed during the day need to be addressed more specifically in future research. [ABSTRACT FROM AUTHOR]