McCaslin, Devin L.

OBJECTIVE Facial nerve function, hearing preservation, and tumor control have been the primary benchmarks used to assess vestibular schwannoma (VS) outcomes. Acknowledging the frequent discrepancy between what physicians prioritize and what patients value, there has been increasing prioritization of patient-reported outcome measures when evaluating the impact of VS diagnosis and its treatment. Motivated by reported limitations of prior instruments used to assess quality of life (QOL) in patients with VS, the authors describe the development and validation of a new disease-specific QOL measure: the Vestibular Schwannoma Quality of Life (VSQOL) Index. METHODS The content development phase comprised identification of clinically important domains and prioritization of feelings or concerns individuals with VS may have. The validation phase encompassed determining how items were grouped into domains and eliminating redundant items. Both phases leveraged data from cross-sectional and longitudinal surveys, expertise from a multidisciplinary working group, and patients with a broad range of experiences with VS (n = 42 during content development and n = 263 during validation). Domain scores from the new instrument were assessed for reliability and correlation with other measures of similar constructs. RESULTS The VSQOL Index consists of 40 items that evaluate the impact of VS diagnosis and its management on QOL, treatment satisfaction, and employment and is estimated to take 8–10 minutes to complete. Domain scores range from 0 (worst) to 100 (best) and demonstrate excellent psychometric properties, including content, construct, and convergent validity and both internal consistency (Cronbach’s alphas 0.83 to 0.91) and test-retest reliability (reliability coefficients 0.86 to 0.96). CONCLUSIONS The VSQOL Index is a valid and reliable measure that overcomes several limitations of prior instruments, including omission or underrepresentation of domains that frequently impact well-being, such as pain, cognition, satisfaction or regret surrounding treatment decisions, and occupational limitations, to comprehensively evaluate the impact of VS diagnosis or its treatment on QOL.

Abstract Background How significant asymmetries in otolith organ function in the presence of symmetrical and asymmetrical semicircular canal function influence skull vibration-induced nystagmus testing (SVINT) has not been well described. Purpose The aim of the study is to examine the agreement between SVINT and caloric testing, ocular vestibular-evoked myogenic potentials (oVEMP), and cervical vestibular-evoked myogenic potentials (cVEMP) for detecting asymmetric vestibular function. Research Design This is a retrospective study of patients presenting with the chief complaint of vertigo, dizziness, or imbalance. Study Sample A total of 812 patients were studied with a median age at testing of 59 years (interquartile range 46‐70; range 18‐93) and included 475 (59%) women. Intervention Either the monothermal warm caloric test or alternate binaural bithermal caloric test, oVEMP, and cVEMP tests were administered to all patients. All patients underwent the SVINT prior to vestibular laboratory testing. Data Collection and Analysis Agreement between tests categorized as normal versus abnormal was summarized using percent concordance (PC). Sensitivity and specificity values were calculated for SVINT compared with other tests of vestibular function. Results There was higher agreement between ipsilateral and contralateral SVINT with the caloric test (PC = 80% and 81%, respectively) compared with oVEMP (PC = 63% and 64%, respectively) and cVEMP (PC = 76% and 78%, respectively). Ipsilateral and contralateral SVINT showed higher sensitivity for the caloric test (sensitivity = 47% and 36%, respectively) compared with oVEMP (sensitivity = 26% and 21%, respectively), or cVEMP (sensitivity = 33% vs. 27%, respectively). Specificity of SVINT was high (>80%) for all assessments of vestibular function. Conclusion The presence of SVIN is a useful indicator of the asymmetry of vestibular function between the two ears when making judgments about semicircular canal asymmetry but is less sensitive to asymmetries in otolith organ function.

Objective: The Dizziness Handicap Inventory (DHI) is a 25-item self-report quantifying dizziness-related physical and emotional symptoms and restrictions in daily activities. DHI scores do not correlate with severity of structural vestibular deficits; thus, high DHI scores may reflect other causes of morbidity. This study investigated the relationship between total DHI scores and the presence of structural, functional, and psychiatric disorders in tertiary neurotology patients. Study Design: Retrospective. Setting: Tertiary center. Patients: Eighty-five patients who underwent multidisciplinary neurotologic evaluations. Intervention: Diagnostic. Main Outcome Measure(s): Active illnesses identified by a multidisciplinary neurotology team were abstracted from medical records, cataloged as structural, functional, or psychiatric disorders, and used to group patients into diagnostic categories: structural (structural disorders only), functional (functional disorders with/without structural disorders), and psychiatric (psychiatric disorders with/without other conditions). DHI scores were compared across diagnostic categories. Sensitivities and specificities of DHI scores for identifying structural versus functional or psychiatric disorders were calculated. Results: Mean DHI scores differed significantly by diagnostic category (structural 35 ± 18, functional 64 ± 15, and psychiatric 65 ± 19), before and after adjusting for age and sex ( p < 0.001, Hedges’ g>1.62 for structural versus functional and psychiatric categories). DHI≤30 (mild handicap) had specificity = 0.98 for structural disorders alone, whereas DHI>60 (severe handicap) had specificity = 0.88 for functional or psychiatric disorders. Conclusions: In this tertiary cohort, categories of illnesses had large effects on total DHI scores. Patients with scores ≤30 were likely to have structural disorders alone, whereas those with scores >60 were likely to have functional or psychiatric disorders, with or without coexisting structural conditions.

PurposeMénière's disease (MD) is a constellation of otologic symptoms that includes aural fullness, tinnitus, hearing loss, and episodic vertigo. Even though the criteria for diagnosing the disorder was set forth in 1972, the causes are still not well understood. The purpose of this study was to describe the relationships between tests of hearing and vestibular function and length of time patients diagnosed with unilateral MD have experienced symptoms.MethodThe charts of 254 patients with definite unilateral MD from the Mayo Clinic database were retrospectively reviewed. In order to be included, patients must have reported active MD diagnosis within the previous 5 years. Main outcome measures were results for audiometry, cervical vestibular evoked myogenic potentials, ocular vestibular evoked myogenic potentials, caloric test findings, video head impulse test, and sinusoidal harmonic acceleration.ResultsResults indicate there is a significant effect of the duration of MD symptoms reported by the patient and findings on some tests of hearing and vestibular function. Specifically, pure-tone average, caloric paresis, and rotational chair phase were all positively correlated with duration of symptoms. Rotational chair gain was found to have an inverse relationship with time. We did not find that video head impulse test gain or certain vestibular evoked myogenic potential measures were significantly correlated with the reported duration of patient symptoms.ConclusionsOur results suggest that, although the duration of symptoms reported by the patient does correlate with a number of vestibular and hearing tests, the relationships are relatively weak. The number of attacks and severity of symptoms should be investigated to determine if they are better predictors of laboratory testing results in the patient with MD.

Objective.: The Dizziness Handicap Inventory (DHI) is a 25-item self-report questionnaire developed to measure the disabling and handicapping impact of dizziness. The present investigation was conducted in an effort to re-assess the factor structure of the DHI. Study Design.: Retrospective study. Setting.: Tertiary care center. Patients.: Subjects were 1,991 patients who were evaluated in the Mayo Clinic-Rochester Vestibular and Balance Laboratory. Main Outcome Measures.: Exploratory factor analysis: an exploratory bifactor analysis (EFA) with bifactor rotation was used to analyze a random sample of 999 patients. Analyses were used to determine the dominance of the general factor (i.e., total score) relative to the group factor (i.e., subscales). Confirmatory factor analysis: a confirmatory bifactor graded response model was fit with appropriate item-to-group relationships that was discovered by our exploratory analyses. To validate the bifactor model that was identified with the exploratory analyses, a bifactor model with three grouping factors (i.e., Physical manifestations, Catastrophic impact of dizziness, and the Emotional impact of dizziness) were fit to a different random sample of 992 patients using the new item-to-group factor specifications. Results.: In the confirmatory analyses, all items had a positive factor loading on the general factor. There were 14 items that loaded on the general factor only. The rest of the items (n = 11) loaded on both the general factor and one of three group factors. Conclusions.: Conclusions of the study revealed several findings: 1) reporting the result as a total score (i.e., a single general factor) is warranted, and, 2) there is statistical support for the existence of three subscales representing: the Physical manifestations, Catastrophic impact, and Emotional impact of dizziness and vertigo.

Objectives The objectives of this study were (a) to investigate the optimal tone burst duration when recording the cervical vestibular evoked myogenic potential (cVEMP) and the ocular vestibular evoked myogenic potential (oVEMP) and (b) to determine whether monopolar recording influences the latency or amplitude of the cVEMP or the oVEMP. Method Fifteen subjects ( M = 27.7 years, SD = 6.73 years) participated in this study. The participants had no prior history of otological or neurological disease. Both oVEMPs and cVEMPs were recorded at a fixed stimulus level for stimulus durations of 2, 5, 10, and 25 ms. For both cVEMP and oVEMP, responses were obtained using a traditional differential recording montage and a monopolar recording montage. Results The cVEMP and the oVEMP had the greatest amplitude in the 2-ms stimulus condition. There was a statistically significant decrease in amplitude for durations greater than 2 ms. Monopolar and bipolar cVEMP and oVEMP latencies and amplitudes were not significantly different. Conclusion As stimulus duration increased beyond 2 ms, the amplitude of the response decreased for both the cVEMP and the oVEMP. There was no significant change in latency with increasing stimulus duration for either response. These results suggested the optimal stimulus duration for both the oVEMP and cVEMP is 2 ms, and there is no apparent advantage of using a bipolar recording technique.

AbstractOculomotor evaluation as part of videonystagmography is an integral tool in the assessment of vestibular function providing a global assessment of the neurological pathways associated with oculomotor function. The value of an oculomotor evaluation for pediatric evaluation is well established; however, many questions can also arise with the application to the pediatric population. Oculomotor function is age dependent which can have a significant effect on the test results obtain in children. The underlying neural substrates and age effects are discussed across the literature with specific results from recent research using clinical oculomotor equipment and protocols. The evidence suggests there are several key differences in the pediatric population compared with adults. These include longer saccade latencies, reduced smooth pursuit gain, increased optokinetic asymmetry, increased variability in all responses, and increased artifact in saccade and smooth pursuit testing.