Misperception of Visual Vertical in Peripheral Vestibular Disorders. A Systematic Review With Meta-Analysis.

OBJECTIVE: The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception. METHODS: A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method. RESULTS: Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV. CONCLUSION: Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.

Vestibular implant: does it really work? A systematic review / Implante vestibular: ele realmente funciona? Uma revisão sistemática

Abstract Introduction: People with vestibular loss present a deficit in the vestibular system, which is primarily responsible for promoting postural control, gaze stabilization, and spatial orientation while the head moves. There is no effective treatment for a bilateral loss of vestibular function. Recently, a vestibular implant was developed for people with bilateral loss of vestibular function to improve this function and, consequently, the quality of life of these patients. Objective: To identify in the scientific literature evidence that vestibular implants in people with vestibular deficit improves vestibular function. Methods: One hundred and forty six articles were found from five databases and 323 articles from the gray literature mentioning the relationship between vestibular implant and vestibular function in humans. The PICOS strategy (Population, Intervention, Comparison and Outcome) was used to define the eligibility criteria. The studies that met the inclusion criteria for this second step were included in a qualitative synthesis, and each type of study was analyzed according to the bias risk assessment of the Joanna Briggs Institute through the critical assessment checklist Joanna Briggs institute for quasi-experimental studies and the Joanna Briggs institute critical assessment checklist for case reports. Results: Of the 21 articles included in reading the full text, 10 studies were selected for the qualitative analysis in the present systematic review. All ten articles analyzed through the critical assessment checklist Joanna Briggs institute showed a low risk of bias. The total number of samples in the evaluated articles was 18 patients with vestibular implants. Conclusions: Taken together, these findings support the feasibility of vestibular implant for restoration of the vestibulo-ocular reflex in a broad frequency range and illustrate new challenges for the development of this technology.

Resumo Introdução: Pessoas com perda vestibular apresentam um déficit no sistema vestibular, o qual é o principal responsável pelo controle postural, pela estabilização do olhar e orientação espacial enquanto a cabeça se movimenta. Não há tratamento efetivo para uma perda vestibular bilateral. Recentemente, foi desenvolvido um implante vestibular para pessoas com perda vestibular bilateral para melhorar essa função e, consequentemente, a qualidade de vida desses pacientes. Objetivo: Identificar na literatura científica evidências de que o implante vestibular melhora a função vestibular de pessoas com déficit vestibular. Método: Cento e quarenta e seis artigos foram encontrados em cinco bases de dados e 323 arti-gos da literatura cinzenta, mencionando a relação entre implante vestibular e função vestibular em humanos. A estratégia PICOS (População, Intervenção, Comparação e Desfechos) foi uti-lizada para definir os critérios de elegibilidade. Os estudos que preencheram os critérios de inclusão para esta segunda etapa foram incluídos em uma síntese qualitativa, e cada tipo de estudo foi analisado de acordo com a avaliação de risco de viés do Joanna Briggs Institute através da critical appraisal checklist for quasi-experimental studies e da critical appraisa lchecklist for case reports. Resultados: Dos 21 artigos incluídos cujos textos completos foram lidos, 10 foram selecionados para a análise qualitativa na presente revisão sistemática. Todos os dez artigos analisados ??através da critical appraisal checklist mostraram um baixo risco de viés. O número total de amostras nos artigos avaliados foi de 18 pacientes com implantes vestibulares. Conclusões: Em conjunto, esses achados apoiam a viabilidade do implante vestibular para a restauração do reflexo vestíbulo-ocular em uma ampla faixa de frequências e ilustram novos desafios para o desenvolvimento desta tecnologia.

Obesity Is Not Associated With Postoperative Complications After Vestibular Schwannoma Surgery in a Large Single Institution Series.

OBJECTIVE: Determine whether elevated body mass index (BMI) is associated with postoperative complications after vestibular schwannoma (VS) surgery. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Two hundred six patients undergoing surgery for VS between 2010 and 2017, grouped into obese and nonobese patients. INTERVENTION: Surgery for VS resection. MAIN OUTCOME MEASURES: Postoperative facial nerve outcomes, length of hospital stay, presence of postoperative cerebrospinal fluid leak, 30-day readmission, return to the operating room, wound complications, cardiovascular and thromboembolic complications. RESULTS: After excluding 1 patient for missing BMI, our cohort included 205 patients. Seventy-nine patients (38.5%) were obese (mean BMI 36.2 kg/m, range 30-55.1) and the remaining 126 (61.5%) were nonobese (mean BMI 25.0, range 18.8-29.8 kg/m). Compared with nonobese patients, obesity was not associated with postoperative cerebrospinal fluid leak (OR 1.1, 95% CI 0.93-1.1), length of hospital stay (OR 0.98, 95% CI 0.65-1.47), 30-day readmission rates (1.04, 95% CI 0.95-1.14), return to operating room (OR 1.05, 95% CI 0.98-1.11), or other wound-related complications (OR 0.99, 95% CI 0.94-1.04). CONCLUSION: In this cohort, elevated BMI was not associated with an increased risk for postoperative complications after VS surgery. Our findings may mitigate concerns associated with surgical management of VS in obese patients.

Drafting a Surgical Procedure Using a Computational Anatomy Driven Approach for Precise, Robust, and Safe Vestibular Neuroprosthesis Placement-When One Size Does Not Fit All.

OBJECTIVE: To design and evaluate a new vestibular implant and surgical procedure that should reach correct electrode placement in 95% of patients in silico. DESIGN: Computational anatomy driven implant and surgery design study. SETTING: Tertiary referral center. PARTICIPANTS: The population comprised 81 patients that had undergone a CT scan of the Mastoid region in the Maastricht University Medical Center. The population was subdivided in a vestibular implant eligible group (28) and a control group (53) without known vestibular loss. INTERVENTIONS: Canal lengths and relationships between landmarks were calculated for every patient. The relationships in group-anatomy were used to model a fenestration site on all three semicircular canals. Each patient's simulated individual distance from the fenestration site to the ampulla was calculated and compared with the populations average to determine if placement would be successful. MAIN OUTCOME MEASURES: Lengths of the semicircular canals, distances from fenestration site to ampulla (intralabyrinthine electrode length), and rate of successful electrode placement (robustness). RESULTS: The canal lengths for the lateral, posterior, and superior canal were respectively 12.1 mm ±â€Š1.07, 18.8 mm ±â€Š1.62, and 17.5 mm ±â€Š1.23, the distances from electrode fenestration site to the ampulla were respectively 3.73 mm ±â€Š0.53, 9.02 mm ±â€Š0.90, and 5.31 mm ±â€Š0.73 and electrode insertions were successful for each respective semicircular canal in 92.6%, 66.7%, and 86.4% of insertions in silico. The implant electrode was subsequently revised to include two more electrodes per lead, resulting in a robustness of 100%. CONCLUSIONS: The computational anatomy approach can be used to design and test surgical procedures. With small changes in electrode design, the proposed surgical procedure's target robustness was reached.

Congenital Refractory Glaucoma: A New Ophthalmic Association of Kabuki Syndrome and its Management With Glaucoma Drainage Devices.

INTRODUCTION: Kabuki syndrome (KS) is a rare congenital and polymalformative condition, traditionally associated with mental retardation, unusual facial features, and skeletal abnormalities. We hereby describe a case of bilateral congenital glaucoma associated with MLL2-mutation KS. To the best of our knowledge, this is the first association of KS with congenital glaucoma. CASE REPORT: The patient was a 3-year-old male of North African ethnicity diagnosed with KS and bilateral congenital glaucoma at the age of 3 months and the first child of a nonconsanguineous healthy couple, with no known genetic conditions within the family. The patient was referred to our tertiary glaucoma center with uncontrollable intraocular pressures between 50 and 60 mm Hg in both eyes. Past ophthalmic history included bilateral trabeculectomies and right retinal detachment with phthisis bulbi. We performed left lensectomy combined with Baerveldt tube insertion in the vitreous cavity, revealing extensive posterior synechiae. Postoperatively, he developed intense inflammation with fibrin and vitreous strand formation, requiring subsequent surgeries and subconjunctival injections of betamethasone. Despite these complications, IOP stabilized between 3 and 6 mm Hg. DISCUSSION: This case confirms congenital glaucoma as a rare association of KS, and highlights the potential high-risk nature of such cases. In our opinion, the presence of high levels of inflammation perioperatively and postoperatively is an indication for primary glaucoma drainage device surgery given the high risk of bleb scarring resulting in recurrent surgical revisions. In view of these observations, we also advocate the use of intensive postoperative anti-inflammatory therapy.

How Well Does Intraoperative Audiologic Monitoring Predict Hearing Outcome During Middle Fossa Vestibular Schwannoma Resection?

OBJECTIVE: To evaluate the association between signal changes during intraoperative audiologic monitoring and postoperative audiometric outcome in patients undergoing vestibular schwannoma (VS) resection via middle cranial fossa (MCF) approach. STUDY DESIGN: Retrospective chart review. SETTING: Academic tertiary referral center. PATIENTS: One hundred twenty-six consecutive patients (mean age 48.6 yrs, range 16-67; mean tumor size 9.9 mm, range 1.8-18.9 mm) who underwent MCF VS resection. INTERVENTIONS: Intraoperative audiologic monitoring using auditory brainstem response (ABR) and direct cochlear nerve action potential (CNAP). MAIN OUTCOME MEASURES: Intraoperative ABR wave V and CNAP N1 amplitudes and postoperative pure-tone average (PTA) and word recognition score (WRS). RESULTS: On ABR, absent wave V amplitude was associated with an 81.1% increase and 82.3% decrease in postoperative PTA and WRS, respectively. On CNAP, decreased or absent N1 amplitude was associated with 47.3 and 100% increase, respectively, in postoperative PTA, and 45.3% and 100% decrease, respectively, in postoperative WRS. Receiver-operating curve analysis showed that ABR combined with CNAP using a Cueva electrode achieved the highest diagnostic accuracy in predicting postoperative hearing decline when measured by WRS class (sensitivity 83.3%, specificity 100%), and performed better compared with each modality alone. CONCLUSION: Intraoperative ABR wave V and CNAP amplitude changes are associated with changes in postoperative hearing, and dual modality monitoring was more diagnostic of postoperative hearing decline compared with each modality alone during MCF VS resection. Overall, intraoperative ABR and CNAP were more specific than sensitive for postoperative hearing decline.

The role of explorative tympanotomy in patients with sudden sensorineural hearing loss with and without perilymphatic fistula.

PURPOSE: The purpose of this study was to describe the role of explorative tympanotomy in patients with Profound Sudden Sensorineural Hearing Loss (SSNHL) without clinical evidence of perilymphatic or labyrinthine fistula and to compare intraoperative findings with the postoperative hearing outcome. STUDY DESIGN: Retrospective study of all patients diagnosed with SSNHL who underwent explorative tympanotomy between 2002 and 2005. SETTINGS: Tertiary care university-affiliated hospital. SUBJECTS AND METHODS: Eighty-two patients were diagnosed with unilateral profound SSNHL and underwent tympanotomy with sealing of the round and oval windows. Values of pure tone audiograms and percentage hearing loss of patients with and without intraoperative diagnosed perilymphatic fistula (PLF) were compared and analyzed. RESULTS: PLF was diagnosed in 28% cases intraoperatively. In most cases, hearing improved significantly after surgery. Interestingly, patients with PLF had a 2.4 times greater decrease of percentage hearing loss compared to patients without PLF. CONCLUSIONS: Explorative tympanotomy seems to be useful in patients with profound SSNHL. Patients with PLF benefit more from the surgical procedure and have better outcome than patients without PLF.

Preoperative vestibular assessment protocol of cochlear implant surgery: an analytical descriptive study / Protocolo de avaliação vestibular pré-operatória da cirurgia de implante coclear: estudo descritivo analítico

Abstract Introduction: Cochlear implants are undeniably an effective method for the recovery of hearing function in patients with hearing loss. Objective: To describe the preoperative vestibular assessment protocol in subjects who will be submitted to cochlear implants. Methods: Our institutional protocol provides the vestibular diagnosis through six simple tests: Romberg and Fukuda tests, assessment for spontaneous nystagmus, Head Impulse Test, evaluation for Head Shaking Nystagmus and caloric test. Results: 21 patients were evaluated with a mean age of 42.75 ± 14.38 years. Only 28% of the sample had all normal test results. The presence of asymmetric vestibular information was documented through the caloric test in 32% of the sample and spontaneous nystagmus was an important clue for the diagnosis. Bilateral vestibular areflexia was present in four subjects, unilateral arreflexia in three and bilateral hyporeflexia in two. The Head Impulse Test was a significant indicator for the diagnosis of areflexia in the tested ear (p = 0.0001). The sensitized Romberg test using a foam pad was able to diagnose severe vestibular function impairment (p = 0.003). Conclusion: The six clinical tests were able to identify the presence or absence of vestibular function and function asymmetry between the ears of the same individual.

Resumo Introdução: Os implantes cocleares (IC) são indiscutivelmente um método eficaz de recuperação da função auditiva de pacientes surdos. Objetivo: Descrever o protocolo de avaliação vestibular pré-operatória em sujeitos que serão submetidos ao IC. Método: Nosso protocolo institucional prevê o diagnóstico vestibular por meio de seis testes simples: testes de Romberg e Fukuda, nistagmo espontâneo, Head Impulse Test, Head Shaking Nistagmus, prova calórica. Resultados: Foram avaliados 21 pacientes com média de 42,75 ± 14,38 anos. Apenas 28% da amostra apresentaram todos os testes normais. A presença de informação vestibular assimétrica foi documentada pela prova calórica em 32% da amostra e o nistagmo espontâneo mostrou-se pista importante para seu diagnóstico. A arreflexia vestibular bilateral foi diagnosticada em quatro sujeitos; arreflexia unilateral em três e hiporreflexia bilateral em dois. O Head Impulse Test mostrou-se indicador significante (p = 0,0001) para diagnosticar arreflexia da orelha testada. O teste de Romberg sensibilizado em almofada foi capaz de diagnosticar os comprometimentos severos da função vestibular (p = 0,003). Conclusão: Os seis testes clínicos foram capazes de identificar a presença ou não de função vestibular e assimetria da função entre as orelhas de um mesmo indivíduo.

Bilateral otoneurological pathology: To operate or not?

OBJECTIVE: To illustrate our experience when managing a complex patient with potentially life-threatening bilateral otological disease facing multisensory compromise including complete loss of audiovestibular function and visual disturbance Clinical presentation: A 67 year old lady, presented with a large left vestibular schwannoma and extensive right cholesteatoma encircling the otic capsule. She underwent translabyrinthine resection of the vestibular schwannoma, resulting in profound sensorineural hearing loss, vestibular hypofunction and corneal scarring following an initial temporary facial palsy. Due to the extent of the disease and good right-sided bone conduction thresholds, the cholesteatoma was managed conservatively utilising a bone-anchored-hearing-aid with regular review by the Skull-Base team. However, following acute deterioration in hearing and disease extension threatening right facial nerve function, the decision was taken for surgical intervention with a view to staged cochlear implantation (CI). INTERVENTION: Our patient underwent right lateral petrousectomy, total osseous labyrinthectomy, and implantation of an intracochlear 'dummy' with blind sac closure of the external auditory canal. Recovery was excellent with no further deterioration in balance and no loss of facial nerve function. CI occurred 3 months post-operatively with good functional outcome. CONCLUSION: We present the management of bilateral complex otoneurological disease with significant risk of multisensory compromise. Size of the left vestibular schwannoma necessitated surgical resection with resultant loss of ipsilateral audiovestibular function. Due to residual right audiovestibular function and the risks of surgery, the extensive right cholesteatoma was managed conservatively until disease progression necessitated surgical intervention. Subsequently it was possible to restore access to open-set speech with a right CI.

Preoperative vestibular assessment protocol of cochlear implant surgery: an analytical descriptive study.

INTRODUCTION: Cochlear implants are undeniably an effective method for the recovery of hearing function in patients with hearing loss. OBJECTIVE: To describe the preoperative vestibular assessment protocol in subjects who will be submitted to cochlear implants. METHODS: Our institutional protocol provides the vestibular diagnosis through six simple tests: Romberg and Fukuda tests, assessment for spontaneous nystagmus, Head Impulse Test, evaluation for Head Shaking Nystagmus and caloric test. RESULTS: 21 patients were evaluated with a mean age of 42.75±14.38 years. Only 28% of the sample had all normal test results. The presence of asymmetric vestibular information was documented through the caloric test in 32% of the sample and spontaneous nystagmus was an important clue for the diagnosis. Bilateral vestibular areflexia was present in four subjects, unilateral arreflexia in three and bilateral hyporeflexia in two. The Head Impulse Test was a significant indicator for the diagnosis of areflexia in the tested ear (p=0.0001). The sensitized Romberg test using a foam pad was able to diagnose severe vestibular function impairment (p=0.003). CONCLUSION: The six clinical tests were able to identify the presence or absence of vestibular function and function asymmetry between the ears of the same individual.

The History and Evolution of Surgery on the Vestibular Labyrinth.

The history of surgery on the vestibular labyrinth is rich but sparsely documented in the literature. The story begins over a century ago with the labyrinthectomy in an era that consisted exclusively of ablative surgery for infection or vertigo. Improved understanding of vestibular physiology and pathology produced an era of selective ablation and hearing preservation that includes semicircular canal occlusion for benign paroxysmal positional vertigo. An era of restoration began with a discovery of superior semicircular canal dehiscence and its repair. The final era of vestibular replacement is upon us as the possibility of successful prosthetic vestibular implantation becomes reality.

Recurrent giant cell fibroblastoma: Malignancy predisposition in Kabuki syndrome revisited.

Kabuki syndrome is a genetic condition characterized by distinctive facial phenotype, mental retardation, and internal organ malformations. Mutations of the epigenetic genes KMT2D and KDM6A cause dysregulation of certain developmental genes and account for the multiple congenital anomalies of the syndrome. Eight cases of malignancies have been reported in young patients with Kabuki syndrome although a causative association to the syndrome has not been established. We report a case of a 12-year-old girl with Kabuki syndrome who developed a tumor on the right side of her neck. A relapsing tumor 19 months after initial excision, proved to be giant cell fibroblastoma. Τhis is the first report of giant cell fibroblastoma -a rare tumor of childhood- in a patient with Kabuki syndrome.

Long-term results of middle fossa plugging of superior semicircular canal dehiscences: clinically and instrumentally demonstrated efficiency in a retrospective series of 16 ears.

The objective of this study is to report the surgical outcome after middle fossa approach (MFA) plugging in patients suffering from a superior semi-circular canal dehiscence (SCD) syndrome. This is a retrospective case review. Tertiary referral center. Sixteen ears in 13 patients with a SCD syndrome suffering from severe and disabling vestibular symptoms with a bony dehiscence on CT scan >3 mm and decreased threshold of cervical vestibular evoked potentials (cVEMPs). We assessed preoperatively: clinical symptoms, hearing, cVEMPs threshold, size of dehiscence and videonystagmography (VNG) with caloric and 100 Hz vibratory tests. Postoperatively, we noted occurrences of neurosurgical complication, evolution of audiological and vestibular symptoms, and evaluation of cVEMP data. Tullio's phenomenon was observed in 13 cases (81.3 %) and subjectively reported hearing loss in seven (43.7 %). All patients were so disabled that they had to stop working. No neurosurgical complications were observed in the postoperative course. In three cases (16.6 %), an ipsilateral and transitory immediate postoperative vestibular deficit associated with a sensorineural hearing loss (SNHL) was noted, which totally resolved with steroids and bed rest. All patients were relieved of audiological and vestibular symptoms and could return to normal activity with a mean follow-up of 31.1 months (range 3-95). No patient had residual SNHL. cVEMPs were performed in 14 ears postoperatively and were normalized in 12 (85.7 %). Two of the three patients operated on both sides kept some degree of unsteadiness and oscillopsia. MFA plugging of the superior semi-circular canal is an efficient and non-hearing deteriorating procedure.

The peculiar cystic vestibular schwannoma: a single-center experience.

OBJECTIVE: The operative management of cystic vestibular schwannoma is more challenging. In this study, we focus on the peculiarity of cystic vestibular schwannoma in terms of management and outcome. We evaluated a homogenous series of consecutive patients with cystic vestibular schwannomas who were operated on with a similar technique and via the same surgical approach. METHODS: The patients with vestibular schwannoma who were operated at our center from 2000 to 2012 were retrospectively analyzed. Those having cystic vestibular schwannomas, recognized by the presence of cystic components both on the preoperative magnetic resonance imaging and intraoperatively, were included. Thirty-seven consecutive patients matched the inclusive criteria. The whole pool of solid vestibular schwannomas with similar tumor extension was used as a control group. The facial nerve outcome is reported early after surgery and after 1-year follow-up. Facial nerve palsy GI-III according to House-Brackmann grading system was considered a favorable outcome. Facial nerve palsy GIV-VI was considered unfavorable. The surgical morbidity in the 2 groups was compared. A special point of interest was the correlation between the cyst pattern and outcome. RESULTS: Cystic vestibular schwannomas are associated with a worse early facial nerve outcome (unfavorable in 37.8% in cystic vestibular schwannoma compared with 17.5% in the solid variant). After 1-year follow-up, 8.1% of the cystic variant had unfavorable facial nerve outcome. Meanwhile, 6.2% of the solid variant had unfavorable outcomes. There was no statistically significant difference between both groups regarding the long-term facial nerve outcome. The cystic variant had a greater postoperative morbidity rates, especially hemorrhage (8.1%), in comparison with solid vestibular schwannoma of the same extension (1.7%). Hydrocephalus without significant hematoma is also significantly greater in the cystic type than the solid variant. Medially located thin walled cysts are related to worse facial nerve outcome. CONCLUSION: Surgery of cystic vestibular schwannomas is associated with a greater rate of morbidity and facial nerve dysfunction compared with the solid variant. Special attention is required during facial dissection to allow functional preservation, especially with tumors with medially located thin walled cysts. Meticulous hemostasis also is required to avoid postoperative hematoma. Close postoperative care is mandatory for early detection and prompt management of possible postoperative complications.

"Seeing" cochlear implant misplacement without imaging test.

Electrode array misplacement is an infrequent complication in cochlear implant surgery. A case report of electrode array insertion into the posterior semicircular canal, and its effects on the vestibular function is described. Video head impulse test (vHIT) has become an exceptional diagnostic tool to study vestibular function. We present our experience using the vHIT to detect a misplaced electrode array after cochlear implant surgery.

Complications of microsurgery of vestibular schwannoma.

BACKGROUND: The aim of this study was to analyze complications of vestibular schwannoma (VS) microsurgery. MATERIAL AND METHODS: A retrospective study was performed in 333 patients with unilateral vestibular schwannoma indicated for surgical treatment between January 1997 and December 2012. Postoperative complications were assessed immediately after VS surgery as well as during outpatient followup. RESULTS: In all 333 patients microsurgical vestibular schwannoma (Koos grade 1: 12, grade 2: 34, grade 3: 62, and grade 4: 225) removal was performed. The main neurological complication was facial nerve dysfunction. The intermediate and poor function (HB III-VI) was observed in 124 cases (45%) immediately after surgery and in 104 cases (33%) on the last followup. We encountered disordered vestibular compensation in 13%, permanent trigeminal nerve dysfunction in 1%, and transient lower cranial nerves (IX-XI) deficit in 6%. Nonneurological complications included CSF leakage in 63% (lateral/medial variant: 99/1%), headache in 9%, and intracerebral hemorrhage in 5%. We did not encounter any case of meningitis. CONCLUSIONS: Our study demonstrates that despite the benefits of advanced high-tech equipment, refined microsurgical instruments, and highly developed neuroimaging technologies, there are still various and significant complications associated with vestibular schwannomas microsurgery.

Acute VOR gain differences for outward vs. inward head impulses.

BACKGROUND: Vestibular rehabilitation is a sub-specialization within the practice of physical therapy that includes treatments designed to reduce gaze instability. Gaze stability exercises are commonly given for head rotations to the left and right, even in subjects with one healthy vestibular system (as in unilateral loss). Few studies have investigated the difference in the angular vestibular ocular reflex gain (aVOR) measured in the acute phase after deafferentation for ipsilesional head rotations that move the head away from center or towards center. OBJECTIVE: The purpose of this study was to compare differences in acute aVOR gain when the head was passively rotated outward from an initially centered position (neck neutral) versus the head being rotated inward. METHODS: We recorded head and eye velocity using video head impulse test equipment in patients with unilateral vestibular pathology scheduled for tumor resection via retrosigmoid approach (n=5) or labyrinthectomy due to Meniere's disease (n=2). RESULTS: We found 1) no difference in the ipsilesional aVOR gain for inward or outward directed head impulse rotations and 2) head velocity is inversely correlated with aVOR gain for ipsilesional but not contralesional rotations. CONCLUSIONS: Bedside testing of the ipsilesional aVOR following acute vestibular ablation can be done with head impulse rotations to either side. In the acute stages, physical therapists should prescribe ipsilesional and contralesional gaze stability exercises.