The Gait Disorientation Test: A New Method for Screening Adults With Dizziness and Imbalance.

OBJECTIVE: To develop and evaluate a new method for identifying gait disorientation due to vestibular dysfunction. DESIGN: The gait disorientation test (GDT) involves a timed comparison of the ability to walk 6.096 m with eyes open versus eyes closed. In this prospective study, participants were grouped based on vestibular function. All participants completed a clinical examination, self-report- and performance-based measures relevant to vestibular rehabilitation, and the tasks for the GDT. Vestibular-impaired participants underwent the criterion standard, videonystagmography and/or rotational chair testing. SETTING: Ambulatory clinic, tertiary referral center. PARTICIPANTS: Participants (N=40) (20 vestibular-impaired, 30 women, 49.9±16.1years old) were enrolled from a convenience/referral sample of 52 adults. MAIN OUTCOME AND MEASURE(S): We determined test-retest reliability using the intraclass correlation coefficient model 3,1; calculated the minimal detectable change (MDC); examined concurrent validity through Spearman correlation coefficients; assessed criterion validity with the area under the curve (AUC) from receiver operator characteristic analysis; and computed the sensitivity, specificity, diagnostic odds ratio (DOR), likelihood ratios for positive (LR+) and negative (LR-) tests, and posttest probabilities of a diagnosis of vestibulopathy. The 95% confidence interval demonstrates measurement uncertainty. RESULTS: Test-retest reliability was 0.887 (0.815, 0.932). The MDC was 3.7 seconds. Correlations with other measures ranged from 0.59 (0.34, 0.76) to -0.85 (-0.92, -0.74). The AUC was 0.910 (0.822, 0.998), using a threshold of 4.5 seconds. The sensitivity and specificity were 0.75 (0.51, 0.91) and 0.95 (0.75, 1), respectively. The DOR=57 (6, 541.47), LR+ =15 (2.18, 103.0), and LR- =0.26 (0.12, 0.9). Positive posttest probabilities were 89%-94%. CONCLUSIONS AND RELEVANCE: The GDT has good reliability, excellent discriminative ability, strong convergent validity, and promising clinical utility.

Resection of middle petroclival meningioma via combined anterior transpetrosal and retrosigmoid approaches at two separate stages: 3D operative video.

Surgical access to the petroclival region poses a challenge to neurosurgeons. A wide range of approaches has been demonstrated in the past. In this video, the authors present a 69-year-old male patient who presented with 3-month history of worsening left-sided numbness. The tumor was totally removed in 2 sessions via anterior transpetrosal and retrosigmoid approaches, respectively. The authors demonstrate 2 separate skull base approaches to resect a petroclival meningioma and discuss pitfalls and problems of management for challenging meningiomas. The authors suggest that surgical approaches to petroclival meningiomas should be selected based on an individual case. A skull base team should be versatile in performing all these approaches. The video can be found here: https://youtu.be/BCVrn3TeNvE .

Single institution experience treating 104 vestibular schwannomas with fractionated stereotactic radiation therapy or stereotactic radiosurgery.

UNLABELLED: The pupose of this study is to assess the long-term outcome and toxicity of fractionated stereotactic radiation therapy (FSRT) and stereotactic radiosurgery (SRS) for 100 vestibular schwannomas treated at a single institution. From 1993 to 2007, 104 patients underwent were treated with radiation therapy for vestibular schwannoma. Forty-eight patients received SRS, with a median prescription dose of 12.5 Gy for SRS (range 9.7-16 Gy). For FSRT, two different fraction schedules were employed: a conventional schedule (ConFSRT) of 1.8 Gy per fraction (Gy/F) for 25 or 28 fractions to a total dose of 45 or 50.4 Gy (n = 19); and a once weekly hypofractionated course (HypoFSRT) consisting of 4 Gy/F for 5 fractions to a total dose of 20 Gy (n = 37). Patients treated with FSRT had better baseline hearing, facial, and trigeminal nerve function, and were more likely to have a diagnosis of NF2. The 5-year progression free rate (PFR) was 97.0 after SRS, 90.5% after HypoFSRT, and 100.0% after ConFSRT (p = NS). Univariate analysis demonstrated that NF2 and larger tumor size (greater than the median) correlated with poorer local control, but prior surgical resection did not. Serviceable hearing was preserved in 60.0% of SRS patients, 63.2% of HypoFSRT patients, and 44.4% of ConFSRT patients (p = 0.6). Similarly, there were no significant differences in 5-year rates of trigeminal toxicity facial nerve toxicity, vestibular dysfunction, or tinnitus. CONCLUSIONS: Equivalent 5-year PFR and toxicity rates are shown for patients with vestibular schwanoma selected for SRS, HypoFSRT, and ConFSRT after multidisciplinary evaluation. Factors correlating with tumor progression included NF2 and larger tumor size.

Combined Transcavernous and Kawase's Approach for Gross Total Resection of a Cavernous Sinus Meningioma.

Microsurgery of cavernous sinus (CS) lesions is generally considered to be associated with a high rate of morbidity and cranial nerve deficits. The success for surgical removal of CS meningiomas is debatable and achieving a good functional outcome with preservation of the cranial nerves is the goal. Surgery of these lesions is challenging, recurrence rates are high, and therapeutic strategies remain controversial. In this video, we present a case of a CS meningioma that extended to Meckel's cave and the posterior fossa in a 46-year-old woman with history of a left-sided cerebellopontine angle World Health Organization (WHO) grade-I meningioma with extension to the left CS. Seven years ago, she had a microsurgical resection of a Cerebellopontine angle (CPA) meningioma. She later received radiotherapy for the slowly growing meningioma of the posterior CS. The patient presented with newly onset headache and facial pain. Magnetic resonance imaging (MRI) showed a meningioma of the left CS and Meckel's cave extending into the ambient cistern, with a mild mass effect on the pons, and a size increase compared with prior imaging. Since this area previously received radiotherapy, and the patient was symptomatic from trigeminal compression, the decision was made to proceed with surgical resection of the tumor via combined transcavernous and anterior petrosectomy. Postoperatively, the patient woke up with the same neurological status. MRI confirmed gross total resection of the tumor. The histopathology was a WHO grade-II chordoid meningioma. The patient is currently receiving radiotherapy. This video demonstrates the surgical approach and the resection steps of this pathology. The link to the video can be found at: https://youtu.be/HrU1VOzUGWU .

Validation of a next-generation sensory organization test in adults with and without vestibular dysfunction.

BACKGROUND: The traditional Sensory Organization Test (T-SOT) is a gold standard balance test; however, the psychometric properties of assessing sensory organization with a virtual-reality-based posturography device have not been established. OBJECTIVE: Our overall aims were to assess the criterion, concurrent, and convergent validity of a next-generation Sensory Organization Test (NG-SOT). METHODS: Thirty-four adults (17 vestibular-impaired) participated. We compared the area under the curve (AUC) for receiver operator characteristic (ROC) analysis for the T-SOT and NG-SOT composite scores. Between-group and between-test differences for the composite and sensory analysis scores from each SOT were assessed using Wilcoxon Rank Sum tests. Additionally, we ran Spearman correlations between the NG-SOT composite score and outcomes of interest. RESULTS: The AUCs for the NG-SOT and T-SOT were 0.950 (0.883, 1) and 0.990 (0.969, 1) respectively (p = 0.168). The median composite, vision, and visual preference scores were lower on the NG-SOT compared to the T-SOT; whereas, the median somatosensory score was higher on the NG-SOT compared to the T-SOT. Associations between the composite score and patient-reported or performance-based outcomes ranged from poor to strong. CONCLUSIONS: The NG-SOT is a valid measure of balance in adults. However, the results of the NG-SOT and T-SOT should not be used interchangeably.

Instrumented Gait Analysis to Identify Persistent Deficits in Gait Stability in Adults With Chronic Vestibular Loss.

Importance: Regaining the ability to walk safely is a high priority for adults with vestibular loss. Thus, practitioners need comprehensive knowledge of vestibulopathic gait to design, provide, and/or interpret outcomes of interventions. To date, few studies have characterized the effects of vestibular loss on gait. Objectives: To investigate the use of an instrumented 2-minute walk test in adults with vestibular loss, to further characterize vestibulopathic gait, and to assess whether those with chronic vestibular loss have enduring gait deficits. Design, Setting, and Participants: This cross-sectional study, conducted between April 3, 2018, and June 27, 2019, recruited adults 20 to 79 years of age from an academic, tertiary, hospital-based, ambulatory care setting who were healthy or had confirmed unilateral or bilateral vestibular hypofunction. Of the 43 adults who were screened from convenience and referred samples, 2 declined, and 7 were excluded because of health conditions. Exposures: The main exposure was the instrumented 2-minute walk test, which was conducted with participants using wearable inertial measurement units while they walked a 10-m path at their self-selected speed and turned 180° in their self-selected direction at either end. Main Outcomes and Measures: The primary measures were spatiotemporal gait metrics (eg, stride length [SL] and peak whole-body turning velocity). Multivariate analysis of variance was used to assess between-group differences. Validity was assessed using the area under the curve from receiver operator characteristic analyses. Results: Data from 17 healthy adults (mean [SD] age, 39.27 [11.20] years; 13 [76%] female) and 13 adults with vestibular loss (mean [SD] age, 60.50 [10.81] years; 6 [46%] female) were analyzed. Very large between-group differences were found for SL (left) (estimated marginal mean [SE] for healthy vs vestibular groups, 1.47 [0.04] m vs 1.31 [0.04] m; Cohen d, 1.35; 95% CI, 0.18-2.52), SL (right) (estimated marginal mean [SE] for healthy vs vestibular groups, 1.46 [0.04] m vs 1.29 [0.04] m; Cohen d, 1.44; 95% CI, 0.25-2.62), and peak turn velocity (estimated marginal mean [SE] for healthy vs vestibular groups, 240.17 [12.78]°/s vs 189.74 [14.70]°/s; Cohen d, 1.23; 95% CI, 0.07-2.40). The area under the curve was 0.79 (95% CI, 0.62-0.95) for SL (left), 0.81 (95% CI, 0.64-0.97) for SL (right), and 0.86 (95% CI, 0.72-0.99) for peak turn velocity. Conclusions and Relevance: In this cross-sectional study, instrumented gait analysis had good discriminative validity and revealed persistent deficits in gait stability in those with chronic vestibular loss. The findings of this study suggest that these clinically and functionally meaningful deficits could be targets for vestibular rehabilitation.

Effect of Repetitive Administration of a Next-generation Sensory Organization Test in Adults With and Without Vestibular Dysfunction.

HYPOTHESIS: The overall aim was to assess the effects of repetitive testing on performance on a next-generation Sensory Organization Test (NG-SOT). BACKGROUND: The psychometric properties of sensory organization assessment with a next-generation posturography device are not fully characterized. Thus, a better understanding of the reliability of the NG-SOT is required to support its use as an outcome measure. METHODS: Forty adults (20 vestibular-impaired) participated. Test-retest reliability was determined using the interclass correlation coefficient [ICC (3,1)] for the composite, somatosensory, vision, vestibular, and visual preference scores. Learning effects were assessed by analyzing the change in the composite score over time. RESULTS: Analyzing the NG-SOT scores across all participants produced the following interclass correlation coefficients [95% confidence interval (CI)]: composite = 0.95 (0.92, 0.97), somatosensory = 0.20 (-0.06, 0.44), vision = 0.93 (0.88, 0.96), vestibular = 0.91 (0.85, 0.94), and visual preference = 0.19 (-0.07, 0.43). The mean differences (95% CI; p value) for the composite score between administrations were: 2.7 (1.0, 4.4; 0.002) for visits 1 and 2; 1.4 (-0.3, 3.1; 0.099) for visits 2 and 3; 0.7 (-1.0, 2.4; 0.403) for visits 3 and 4; and 0.4 (-1.3, 2.1; 0.653) for visits 4 and 5. CONCLUSIONS: Test-retest reliability was excellent for the composite, vision, and vestibular scores, but it was poor for the somatosensory and visual preference scores. A learning effect for the composite score was identified, but performance was stable after two administrations. Changes in the composite score that are greater than 6.5 points exceed the measurement error for the test.

The Temporoparietal Fascia Flap is an Effective Strategy for Cochlear Implant Wound Coverage.

OBJECTIVE: To report the rate of major soft tissue complications after cochlear implantation and to describe the use of the temporoparietal fascia (TPF) flap for such complications. STUDY DESIGN: Retrospective case series. SETTING: Tertiary care, University Hospital. SUBJECTS AND METHODS: Chart review of all patients who underwent cochlear device implantation over a 5-year period to identify patients and to determine the rate of soft tissue complications. Five patients with major soft tissue complications underwent TPF flap with device salvage or explantation/reimplantation. RESULTS: The rate of major skin complications was 6 out of 281 (2.1%) over 5 years, with 5 patients undergoing TPF flap. The average follow-up was 25.8 months (range, 5-58 months). TPF flap represented the definitive, successful solution for all 5 patients. One postoperative hematoma occurred after TPF flap, with no long-term sequelae. The average hospital length of stay was 2.2 nights (range, 1-5 nights). One patient required IV antibiotics for 4 weeks; the remaining patients were treated with a postoperative course of oral antibiotics. The original device remained in place for 4 patients, while one case required device explantation and staged re-implantation. Post-TPF flap hearing results were equal to if not superior to their preoperative results. CONCLUSION: Major soft tissue complications following cochlear device implantation are rare. The temporoparietal fascia flap is an excellent option for reconstruction of device site soft tissue dehiscences when local wound care and primary closure are not sufficient, and can potentially prevent explantation of a functional implant.

Endolymphatic sac decompression as a treatment for Meniere's disease.

OBJECTIVES/HYPOTHESIS: Endolymphatic sac decompression is a surgical treatment option for patients with medically intractable Meniere's disease. However, effectiveness is debated because published data show great variability. Outcome-based research studies are useful in incorporating the patient's perspective on the success of treatment. To further assess effectiveness of endolymphatic sac decompression, we performed a prospective study to examine both symptom-specific and general health outcomes. STUDY DESIGN: Prospective, observational outcome study. METHODS: Nineteen patients with endolymphatic sac decompression responded to symptom-specific questionnaires and the Medical Outcomes Short-Form 36 Health Survey (SF-36) before and after surgery. Follow-up ranged from 6 to 58 months with a mean duration of 50 months. RESULTS: Overall measures of physical health were significantly improved following endolymphatic sac decompression (P = .04), whereas overall measures of mental health were unchanged (P = .74). Role Physical and Social Functioning scores were significantly improved following endolymphatic sac decompression (P = .04 and P = .03, respectively). Study patients scored significantly lower (P < .05) than SF-36 normative data in 6 of 10 categories before endolymphatic sac decompression but patient scores were not significantly different from normal scores in all but one category (General Health) following endolymphatic sac decompression. The mean number of vertigo episodes was significantly reduced from an average of 8.3 times per month to an average of 2.6 times per month following endolymphatic sac decompression (P = .006). Ninety-five percent of patients (18 of 19 patients) reported improvement in symptoms (frequency, duration, or intensity) of vertigo and 37% (7 of 19 patients) reported complete resolution of vertigo. CONCLUSION: Endolymphatic sac decompression significantly improved perception of physical health, as well as symptom-specific outcomes, in patients with medically intractable Meniere's disease.

Effects of vestibular and balance rehabilitation on sensory organization and dizziness handicap.

This retrospective study was undertaken to assess balance recovery and dizziness handicap in 32 patients after a vestibular and balance rehabilitation program. Outcomes were compared between 12 patients with peripheral vestibular disorders and 20 patients with central or mixed balance disorders. The patients were tested with posturography (sensory organization test [SOT]) and the Dizziness Handicap Inventory (DHI) before and after their therapy program. The vestibular SOT, composite SOT, and functional DHI scores obtained before and after exercise were significantly improved in both the peripheral and central groups. The visual SOT mean scores obtained before and after therapy were significantly different only for the group with central or mixed vestibular disorders. Changes in SOT scores were not directly correlated with changes in DHI scores. Outcome measures of vestibular rehabilitation protocols confirmed objective and subjective improvement of balance and dizziness handicap in patients with peripheral and central vestibular disorders.

Correlation between auditory function and internal auditory canal pressure in patients with vestibular schwannomas.

OBJECT: Hearing loss is the most common presenting symptom in patients who harbor a vestibular schwannoma (VS). Although mechanical injury to the cochlear nerve and vascular compromise of the auditory apparatus have been proposed, the exact mechanism of this hearing loss remains unclear. To test whether pressure on the cochlear nerve from tumor growth in the internal auditory canal (IAC) is responsible for this clinical finding, the authors prospectively evaluated intracanalicular pressure (ICaP) in patients with VS and correlated this with preoperative brainstem response. METHODS: In 40 consecutive patients undergoing a retrosigmoid-transmeatal approach for tumor excision, ICaP was measured by inserting a pressure microsensor into the IAC before any tumor manipulation. Pressure recordings were correlated with tumor size and preoperative auditory evoked potential (AEP) recordings. The ICaP, which varied widely among patients (range 0-45 mm Hg), was significantly elevated in most patients (median 16 mm Hg). Although these pressure measurements directly correlated to the extension of tumor into the IAC (p = 0.001), they did not correlate to total tumor size (p = 0.2). In 20 patients in whom baseline AEP recordings were available, the ICaP directly correlated to wave V latency (p = 0.0001), suggesting that pressure from tumor growth in the IAC may be responsible for hearing loss in these patients. CONCLUSIONS: Tumor growth into the IAC results in elevation of ICaP and may play a role in hearing loss in patients with VS. The relevance of these findings to the surgical treatment of these tumors is discussed.

Outcomes in vestibular ablative procedures.

OBJECTIVE: To assess dizziness handicap and postural recovery in 17 patients undergoing a vestibular ablative procedure. STUDY DESIGN: Outcomes were compared between nine patients who underwent selective vestibular neurectomy and eight patients who underwent a transmastoid labyrinthectomy. SETTING: Patients underwent ablative procedures at a tertiary care facility. METHODS: Patients were tested with posturography (sensory organization test [SOT]) and the Dizziness Handicap Inventory (DHI) before and 4 to 5 weeks after their procedure. RESULTS: The mean change scores for each of the DHI subscales and the total DHI score showed significant improvement for the labyrinthectomy group. For the neurectomy group, only the emotional DHI subscale change score showed significant improvement. No difference was noted between preprocedure and postprocedure SOT scores for either group. The results indicated that the largest proportion of significant correlations existed between DHI and the somatosensory and vestibular subtests of platform posturography. In regression analyses, a model with age (p = 0.04) and vestibular score (p = 0.001) fitted the data well and explained 52.9% of the variance. Persons who were less than 69 years old were three times more likely to report persistent episodes of dizziness after the ablative procedure, and those who had neurectomies were 2.3 times more likely to report episodes of dizziness than those who underwent transmastoid labyrinthectomy. CONCLUSION: Dizziness handicap after an ablative procedure is influenced by the type of procedure (labyrinthectomy versus neurectomy), age, and preoperative vestibular score on the SOT. Preoperative vestibular SOT score is highly associated with the emotional, physical, and functional domains of perceived handicap and quality of life after the surgery.

Transmastoid approach to the superior semicircular canal: An anatomical study.

OBJECTIVE: We examined the anatomic features of the top of the superior semicircular canal (SSC) to help guide the surgeon considering resurfacing or plugging of an associated dehiscence, thorough the transmastoid (TM) approach. METHODS: 19 selected cadaveric temporal bones, which had no supralabyrinthine tract, were dissected, and distances between the SSC and various structures within the temporal bone were measured with a, fine caliper. RESULTS: The average distances from the sino-dural angle, horizontal canal top, and subacurate artery, to the top of the SSC were 31.1, 7.8, and 3.9 mm, within a small range. 7 (36.8%) out of 19 bones with a, low hanging tegmen needed a wide exposure and elevation of the dura to access the SSC top. CONCLUSION: Knowledge of the anatomical details associated with the SSC from this study may help to, access the SCC dehiscence safely for resurfacing surgery via a TM approach.