Impact of the Vestibular System on the Formation and Progression to Idiopathic Scoliosis: A Review of Literature.

The physiopathogenesis of adolescent idiopathic scoliosis remains unknown. However, a multifactorial pathogenesis is being assumed. Besides biomechanical, biochemical, and genetic factors, some studies have focused on congenital or acquired abnormalities in the vestibular organ with consecutive development of scoliosis. This study aims to analyze a possible correlation between any vestibular organ congenital or acquired pathologies and scoliosis based on the current literature. Therefore, we conducted a literature search in three databases, with search terms such as "scoliosis," "organ of balance," "idiopathic scoliosis," "vestibular organ," "spine," and "balance." Fifteen studies were selected and used for research. The relationship between scoliosis and vestibular organ abnormalities was recorded from all included works. Seven studies demonstrated a direct correlation between vestibular organ anatomical abnormalities and the form of the scoliotic spine. Another study confirmed the influence of the pathology of the vestibular organ on scoliosis but questioned whether it had an impact on the formation or the progression of the curvature. Others demonstrated a temporal overlap of the embryonic development of the vestibular organ and the beginning of pre-scoliotic characteristics, but their relationship remained questionable. In three studies, the correlation remained unclear, and any context has been denied. It seems unlikely that an isolated vestibular disorder can trigger structural scoliosis. However, the vestibular system pathologies may certainly occur in the multifactorial genesis of idiopathic scoliosis. Whether the correlation refers to the expression or the progression of scoliosis or may even have an influence on both remains unclear. New treatment options could be derived from these findings with a positive influence on the course of the deformity.

Preservation of Vestibular Function and Residual Hearing After Round Window Cochlear Implantation.

OBJECTIVE: To examine the possible correlation between the loss of short-term residual hearing and vestibular function after cochlear implantation (CI). STUDY DESIGN: Retrospective patient review. SETTING: Academic tertiary referral center. PATIENTS: One hundred twenty patients with normal vestibular function (VF) in the caloric testing and residual hearing (RH) at the frequencies 250, 500, and 1000 Hz on the surgery side between 2008 and 2016 were included in the study. INTERVENTION: Primary CI on the first side via round window with a conventional full-length electrode. MAIN OUTCOME MEASURES: Changes of RH and VF 7 weeks after surgery were analyzed. Preservation of RH was defined as measurable postoperative thresholds at the frequencies 250, 500, and 1000 Hz in the pure-tone audiogram. Preservation of the VF after CI was assessed both by an absolute and relative threshold in the caloric testing. RESULTS: Seven weeks after implantation, the preservation of RH was achieved in 52 (43.3 %) patients and the preservation of VF in 95 (79.2 %) patients on the operated side. There was no significant statistical correlation between these two parameters. CONCLUSION: The loss of RH was more than twice as frequent as the loss of VF. However, no statistical correlation between the failure of the two inner ear functions was found. The exact causes are still unknown, but our data could give an indication that there may be different underlying pathomechanisms.

Influence of ambient air pressure changes on vestibular symptoms after stapes surgery.

OBJECTIVE: To examine if vestibular irritation after stapes surgery may be provoked by pressure changes across the tympanic membrane, which consecutively results in displacements of the ossicular chain and the piston prosthesis suspended to it. METHODS: In this prospective study 15 patients (13 female, 2 male) received unilateral stapes surgery (4 left, 11 right ear) with stapedotomy (n=14) or stapedectomy (n=1) at an academic tertiary referral center. Surgery was performed under local anesthesia via a transmeatal approach with a piston prosthesis 0.4×4.5mm. The fixation of the stapes, the exclusion of a malleus head fixation, and the gliding capacity of the malleus-incus joint were examined intraoperatively. A pure tone audiogram at four frequencies, a tympanometry with simultaneous video-oculography (VOG), caloric testing, and posturography with and without simultaneous tympanometry were performed six days before surgery, six weeks and three months after surgery, respectively. RESULTS: The mean air bone gap improved significantly from 25 (±8) dB preoperatively to 10 (±6) dB after surgery. In the tympanometry with simultaneous VOG only two patients showed nystagmus beats into the operated ears during only one of the two follow-up appointments. All other patients did not show any vestibular symptoms or nystagmus during any of the follow-up appointments. In the combined testing of posturography and tympanometry no patient showed any pathological findings. CONCLUSION: In patients who underwent stapes surgery with a piston prosthesis no vestibular symptoms can be provoked by pressure changes in the external auditory canal.

Prevalence of Barotrauma in Recreational Scuba Divers After Repetitive Saltwater Dives.

INTRODUCTION: The aim was to investigate the prevalence of middle ear barotrauma (MEB) and to establish risk factors of MEB after repeated saltwater dives. METHODS: In this prospective observational cohort study 28 divers were examined over 6 consecutive days of diving in the Red Sea, Egypt. Participants underwent an otoscopic examination before the first dive, between each dive and after the last dive. In addition, they performed Valsalva maneuver (VM) and were questioned about dive-related complaints. Otoscopic findings were classified according to TEED classification for MEB (0 = normal otoscopy to 4 = perforation) separately for each ear. First examination was conducted before the first dive. Final examination, including a questionnaire, was conducted at least 12 h after the last dive. RESULTS: In total, 436 dives were performed and 1161 otoscopic findings were analyzed. All participants showed a normal eardrum and a positive VM during initial exam. MEB prevalence (TEED >0) was 36.5% at final examination. Prevalence increased significantly with number of dives per day (p < 0.001) as with number of diving days (p = 0.032). Neither depth nor duration of dives significantly influenced MEB prevalence (all p > 0.05). More experienced divers (>200 dives lifetime) showed significantly less barotrauma (p < 0.0001). Despite the high prevalence of MEB, 81.7% (316 of 387) of all dives were reported asymptomatic. CONCLUSIONS: After 6 days of repetitive diving, MEB prevalence was high (36.5%). It was the most often cause of otalgia in divers. Cumulative pressure exposure during repetitive dives resulted in significant increase of MEB. Diving experience significantly reduced the MEB prevalence. Interestingly, the severity of MEB did not correlate with subjective complaints.

Postural control before and after cochlear implantation: standard cochleostomy versus round window approach.

CONCLUSION: The approach to the cochlea did not influence postural control after cochlear implantation (CI) surgery. Most patients already have impaired vestibular function before surgery. These balance deficits did not change after CI surgery in the majority of patients but static balance might be improved by CI surgery. OBJECTIVES: To determine whether the technique used to insert the CI electrode has an influence on vestibular function. METHODS: Static and dynamic postural control and caloric vestibular function were measured prospectively before and after CI surgery in 36 CI patients with standard cochleostomy (SC) insertion and 16 patients with insertion across the round window (RW). The test battery consisted of the modified clinical test of sensory interaction on balance (mCTSIB), the Rhythmic Weight Shift (RWS), the Walk Across (WA), and the Tandem Walk (TW) test. RESULTS: Caloric testing was normal in the majority of CI candidates and remained normal after surgery. mCTSIB results were not significantly different before and after CI surgery between the SC and RW groups. Within both subgroups, the mCTSIB composite value improved within 6 weeks after surgery compared with the values obtained before surgery. Dynamic standing balance showed no postoperative change in RWS.

Static and dynamic postural control before and after cochlear implantation in adult patients.

On a Balance Master computerized force plate static and dynamic postural control was measured in 24 severe hearing-impaired patients before and after CI surgery, and 19 healthy adults in a prospective study. The test battery consisted of the modified clinical test of sensory interaction on balance, the Rhythmic Weight Shift, the Walk Across, and the Tandem Walk test. Postural control was significantly worse in CI candidates than in healthy adults. In contrast, caloric testing of the vestibular organ was normal in the majority of CI candidates and remained normal after CI surgery. Static and dynamic standing balance parameters remained unchanged after CI surgery for the vast majority of parameters. Male gender and age >51 years were negative risk factors in some balance tasks. The static and dynamic standing balance performance seemed to improve to some degree with longer time interval before the CI surgery. Postural control was impaired but not complained of in many CI candidates before CI surgery and remained impaired after CI surgery although caloric testing is normal in most patients.