Vestibular Migraine Confounds Management of Superior Canal Dehiscence Syndrome.

OBJECTIVE: To investigate the prevalence of vestibular migraine (VM) in a cohort of patients with radiologic confirmation of superior canal dehiscence (SCD) and to compare management of superior canal dehiscence syndrome (SCDS) in patients with and without comorbid VM. STUDY DESIGN: Retrospective review of a SCD database. SETTING: University-based tertiary medical center. PATIENTS: Ninety-one patients identified with SCD from 2009 to 2017. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Coincidence of VM and SCD, and resolution of symptoms. RESULTS: Ninety-one patients with SCD met the inclusion and exclusion criteria. VM was diagnosed in 36 (39.6%) patients. Of those receiving medical therapy for VM alone, five (45.5%) reported symptom resolution, five (45.5%) reported partial improvement, one (9.1%) had no change, and none worsened. Fifteen patients (41.7%) were treated with both surgery (for SCD) and medical therapy (for VM). Seven (46.7%) reported symptom resolution, seven (46.7%) reported partial improvement, and one (6.7%) worsened. There was no statistically significant difference in symptom resolution between SCD + VM patients who were treated medically compared with those treated with medical therapy and surgery (p = 0.951). There was no significant difference in symptom resolution after surgery between SCD + VM and SCD-only cohorts (p = 0.286). CONCLUSIONS: This is the first study describing the incidence of VM in a cohort of patients with SCDS. The symptoms of VM confound those of SCDS and unrecognized or undertreated VM may contribute to surgical failure in SCDS. Therefore, we recommend a high index of suspicion for VM in patients with SCDS and a trial of medical therapy in the setting of suspected VM.

Endoscope-Assisted Superior Semicircular Canal Dehiscence Repair: Single Institution Outcomes.

OBJECTIVE: To compare outcomes of endoscope-assisted middle cranial fossa MCF) repair of superior semicircular canal dehiscence (SSCD) compared to microscopic MCF repair. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary medical center neurotology practice. METHODS: Retrospective chart review and cohort study of patients who underwent surgical repair of SSCD via MCF approach from 2010 to 2019 at our institution. Patients were categorized according to use of endoscope intraoperatively. Pre- and post-operative symptom number was calculated from 8 patient-reported symptoms. Pre- and post-operative changes in symptom number were assessed using paired t-tests. Single-predictor binary logistic regression was used to compare final reported symptoms between cohorts. Linear regression was performed to assess air-bone gap (ABG) changes postoperatively between cohorts. RESULTS: Forty-six patients received surgical management for SSCD. Of these, 27 (59%) were male and 19 (41%) were female. Bilateral SSCD was present in 14 cases (29%), of which 3 underwent surgical management bilaterally, for a total of 49 surgical ears. Surgery was performed on the right ear in 19 cases (39%) and on the left in 30 cases (61%). Forty ears (82%) underwent microscopic repair while 9 (18%) underwent endoscope-assisted repair. Microscopic and endoscope-assisted MCF repair both demonstrated significantly improved symptom number postoperatively (P < .001 for each). There was no significant difference in change in ABG between the 2 cohorts. On average, patient-reported symptoms and audiometrically-tested hearing improved postoperatively in both groups. CONCLUSION: While endoscopic-assisted MCF repair has the potential to provide better visualization of medial and downslope defects, repair via this technique yields similar results and is equivalent to MCF repair utilizing the microscope alone.

Effects of Lifestyle Modification on Vestibular Migraine.

OBJECTIVE: To evaluate effects of lifestyle modification on symptoms of dizziness and headache in patients diagnosed with definite vestibular migraine. STUDY DESIGN: Prospective within-participants repeated-measures study. SETTING: Otolaryngology tertiary care. PARTICIPANTS: Twenty-eight adults with definite vestibular migraine who were willing to be treated without pharmacological intervention. INTERVENTIONS: Information and instructions were provided on lifestyle modification; participants were instructed to improve restful sleep, exercise, eat at regulated mealtimes, and avoid dietary triggers. Participants were asked to maintain the modifications for at least 60 days. MAIN OUTCOME MEASURES: Two self-report inventories were used pre- and post-intervention to evaluate participants' perceived dizziness handicap and headache disability using the Dizziness Handicap Inventory and Headache Disability Inventory, respectively. Questions were also used to evaluate the extent to which participants reported compliance with lifestyle factors pre- and post-intervention. RESULTS: Significant improvement was observed after the lifestyle intervention with mean improvements in Dizziness Handicap Inventory and Headache Disability Inventory of 14.3 points. As a group, improvement in restful sleep was related to improvement in both dizziness and headache symptoms. At the individual participant level, 39% and 18% of participants reported significant reduction in dizziness handicap and headache disability, respectively. CONCLUSIONS: Lifestyle modifications are an effective intervention for symptoms of dizziness and headache in participants with definite vestibular migraine. Participants who reported a larger increase in restful sleep were more likely to also report larger improvements in dizziness handicap and headache disability. Effect sizes using the current intervention were comparable or better than some reported pharmacological interventions but less than others. Our lifestyle modification intervention produced significant improvement in dizziness for a larger percentage of individual participants and in headache for a similar percentage of participants compared to data reported with other lifestyle modification interventions. Lifestyle modifications, especially restful sleep, have the potential to reduce the impact of vestibular migraine on patients' lives, with limited risk.Clinical Trials Registration: NCT03979677.

Test-Retest Reliability of the Dizziness Symptom Profile.

OBJECTIVES: This investigation was conducted to measure the test-retest reliability of the Dizziness Symptom Profile (DSP). The DSP was developed to assist primary care providers, general otolaryngologists, and other health care providers in the development of a differential diagnosis for patients who present with dizziness, vertigo, or unsteadiness. The DSP yields a score ranging from 0 to 100% for each of 7 subscales. Each subscale represents a different diagnosis including benign paroxysmal positional vertigo, Ménière's disease, persistent postural-perceptual dizziness (PPPD), superior semi-circular canal dehiscence, vestibular migraine, vestibular neuritis, and general unsteadiness. DESIGN: Subjects were 150 adult patients (mean age 56.79 years, SD 15.69 years) referred to the Balance Disorders Clinic at Vanderbilt University Medical Center. Subjects completed two administrations of the DSP. The mean interval between test administrations was 1.58 days (SD 1.78 days). The response modes for the DSP were both a 0 to 100 mm visual analog scale (scored 0 mm = "strongly disagree" to 100 mm = "strongly agree") and, by extrapolation, the original 5-point Likert scale where the anchors were "strongly disagree" (scored 0 points) and "strongly agree" (scored 4 points). RESULTS: Pearson correlation coefficients were calculated to assess test-retest reliability for individual DSP items, and ranged from r = 0.67 to 0.91 (mean 0.80; p < 0.001). Cronbach's α coefficients were calculated to assess internal consistency reliability of items comprising the seven subscales. Each subscale had an acceptable level of internal consistency (Cronbach's α coefficients > 0.7) with the exception of PPPD which approached 0.7. Intraclass correlation coefficient estimates and their 95% confidence intervals were also calculated to assess the relative reliability of the subscales. All 7 subscales showed moderate to strong test-retest reliability, with intraclass correlation coefficients ranging from 0.85 to 0.94. Minimal detectable change (MDC) scores were calculated to assess absolute variability/measurement error for the seven subscale scores (which range from 0 to 100%). MDC values ranged from 16% (PPPD) to 25% (unsteadiness). CONCLUSIONS: (1) The test-retest reliability of the DSP is moderate to strong. (2) MDC values for each subscale were determined. (3) The DSP coupled with the Dizziness Handicap Inventory enables the clinician to evaluate the constructs of dizziness impairment, and disability/handicap. (4) The DSP may help provide a window to the natural history of dizziness disease(s). (5) The DSP provides a less biased assessment of the symptoms reported by the patient.

Multiple Co-Occurring Vestibular Disorders Identified Using the Dizziness Symptom Profile.

Purpose The purpose of the current investigation was to determine the interrelations among vestibular disorders from a data set generated from the patient perspective as compared to previous data generated from the physician's perspective. Method The data for the current investigation originated from a previously published study describing the development of the Dizziness Symptom Profile (DSP; Jacobson et al., 2019). The DSP is a 31-item patient self-report tool designed to help primary care physicians in the development of a differential diagnosis using the patient's level of agreement with each dizziness and symptom-related statement. Responses to these items converge on common vestibular diagnoses and were previously found to agree with ear specialist differential diagnoses 70.3% of the time. Data were collected for 131 subjects (M age = 56.7 years, 72 women) seen for evaluation in a tertiary dizziness specialty clinic. For this study, the data were analyzed using descriptive statistics to determine the frequency of single diagnoses, multiple diagnoses, co-occurring diagnoses, and patterns of co-occurrence. Results Results indicated that 52.7% of patients endorsed a single vestibular diagnosis and 47.3% endorsed two or more vestibular diagnoses. Benign paroxysmal positional vertigo (BPPV) and vestibular migraine were the most common single diagnoses and also the most common co-occurring diagnoses. As the number of diagnoses endorsed on the DSP increased, so did the percentage of time that BPPV and vestibular migraine would occur. Conclusions Results support and extend the work of others but using data generated from the perspective of the patient. A slight majority of patients endorsed a single disorder, but almost as many patients endorsed more than one vestibular diagnosis. BPPV and vestibular migraine were the most common single vestibular diagnoses and also the most common co-occurring vestibular diagnoses; vestibular migraine was more common when multiple diagnoses were endorsed. Results suggest it is common for patients to volunteer symptoms that cannot be explained by a single vestibular diagnosis. This finding is in agreement with physician-generated diagnosis data. Clinicians should consider the possibility of co-occurring diagnoses in complicated patients or in patients who are not responding optimally to management of a single vestibular disorder. The DSP is a tool that encourages clinicians to consider multiple co-occurring vestibular disorders as the source of patient complaints.

A factor analytic assessment of the English translation of the neuropsychological vertigo inventory (NVI).

PURPOSE: Vestibular impairments have been associated with a variety of cognitive deficits, most notably deficits in visuo-spatial memory. The Neuropsychological Vertigo Inventory (NVI) was developed to measure self-reported cognitive deficits in patients with dizziness and/or vertigo. The original French language version of the NVI includes 28 items and 7 subscales. The purpose of the present investigation was to determine whether the statistical assessment of an English language version supported the presence of the same cognitive constructs as the French version of the NVI. METHOD: The English language adaptation of the NVI (referred to here as the NVIe) was administered to an unselected sample of 280 patients that were being evaluated for dizziness and/or vertigo in a tertiary care dizziness clinic. The individual item scores from the NVIe were subjected to an exploratory factor analysis (EFA). RESULTS: The results of the data analysis supported a 22-item NVIe consisting of 4 constructs: affective state, temporal memory, spatial memory, visual spatial cognition. CONCLUSIONS: The NVIe is a new tool for screening cognitive constructs that may be affected by vestibular impairments. Prior to clinical implementation of the NVIe, additional studies of reliability and convergent validity are needed.

Short Communication: The Belly-Tendon Derivation Yields Superior Ocular Vestibular Evoked Myogenic Potential Amplitudes in a Normal Pediatric Sample.

Purpose The purpose of the investigation was to determine whether the "belly-tendon" electrode derivation produced ocular vestibular evoked myogenic potentials (oVEMPs) in children that were superior to those recorded with the infraorbital-chin electrode derivation. Method This was a prospective observational study using a sample of convenience at a tertiary care medical center. Subjects were 13 children between the ages of 5 and 12 years. We compared the latency of the N1 wave and the N1-P1 peak-to-peak amplitude for the belly-tendon electrode derivation to the infraorbital-chin electrode derivation. Results The belly-tendon electrode derivation was associated with superior N1-P1 amplitudes compared to the infraorbital-chin electrode derivation. However, the large amplitude was also associated with greater variability compared to the infraorbital-chin derivation. There were no significant electrode derivation-based differences in N1 latency. Additionally, there was no predictable relationship between age and oVEMP amplitude. Conclusion As shown previously in adults, the belly-tendon electrode derivation produces significantly larger oVEMP amplitudes compared to the infraorbital-chin electrode derivation.

A Comparison of Two Recording Montages for Ocular Vestibular Evoked Myogenic Potentials in Patients with Superior Canal Dehiscence Syndrome.

OBJECTIVE: The purpose of this investigation was to evaluate the sensitivity and specificity of the ocular vestibular evoked myogenic potential (oVEMP) using two electrode montages in patients with confirmed unilateral superior semicircular canal dehiscence syndrome (SCDS). STUDY DESIGN: This study evaluated oVEMP response characteristics measured using two different electrode montages from 12 unilateral SCDS ears and 36 age-matched control ears (age range = 23-66). The oVEMP responses were elicited using 500 Hz tone-burst air conduction stimuli presented at an intensity of 95 dB nHL and a rate of 5.1/sec. The two electrode montages used are described as an "infraorbital" montage and a "belly-tendon" montage. SETTING: Balance function laboratory embedded in a large, tertiary care otology clinic. RESULTS: The belly-tendon electrode montage resulted in significantly larger amplitude responses than the infraorbital electrode montage for the ears with SCDS and the normal control ears. For both electrode montages the ear with SCDS exhibited a significantly larger amplitude response, ∼50% larger than the response amplitude from the normal control ear. The belly-tendon montage additionally produced larger median increases in amplitude compared with the infraorbital montage. Specifically, the median increase in oVEMP N1-P1 amplitudes using the belly-tendon montage was 39% greater in control ears, 76% greater in the SCDS ears, and 17% greater in the contralateral SCDS ears. CONCLUSIONS: The belly-tendon electrode montage yields significantly larger oVEMP amplitude responses for participants with SCDS and normal control participants.

Development and Preliminary Findings of the Dizziness Symptom Profile.

OBJECTIVES: Dizziness, vertigo, and unsteadiness are common complaints of patients who present to primary care providers. These patients often are referred to otology for assessment and management. Unfortunately, there are a small number of specialists to manage these patients. However, there are several dizziness disorders that can be successfully managed by primary care providers if the disorder is properly identified. To assist in the identification of several of the most common dizziness disorders, we developed the dizziness symptom profile (DSP). The DSP is a self-report questionnaire designed to generate one or more differential diagnoses that can be combined with the patient's case history and physical examination. DESIGN: This report describes three investigations. Investigations 1 and 2 (i.e., exploratory and confirmatory investigations, N = 514) describe the development of the DSP. Investigation 3 (N = 195) is a validation study that describes the level of agreement between the DSP completed by the patient, and, the differential diagnosis of the otologist. RESULTS: The final version of the DSP consists of 31 items. Preliminary findings suggest that the DSP is in agreement with the differential diagnoses of ear specialists for Meniere's disease (100% agreement), vestibular migraine (95% agreement), and benign paroxysmal positional vertigo (82% agreement). CONCLUSIONS: Early results suggest that DSP may be useful in the creation of differential diagnoses for dizzy patients that can be evaluated and managed locally. This has the potential to reduce the burden on primary care providers and reduce delays in the diagnosis of common dizziness and vertigo disorders.

Assessment of Subjective Visual Vertical (SVV) Using the "Bucket Test" and the Virtual SVV System.

OBJECTIVE: The purpose of this study was to describe the variability and test-retest reliability of a commercially available subjective visual vertical (SVV) system known as Virtual SVV (Interacoustics). In addition, the study aimed to compare the reliability of the Virtual system with a previously established bucket test of SVV. STUDY DESIGN: Fifteen participants with normal hearing, normal middle ear function, and normal utricular function were included in the study. Each participant underwent static SVV testing using both the Virtual system and the bucket test. Subjects completed 2 testing sessions to determine test-retest reliability. For each test, data were collected with the head at 0°, tilted 45° to the right, and tilted 45° to the left. SETTING: This study was conducted in a balance function laboratory embedded in a large, tertiary care otology clinic. RESULTS: The mean SVV values obtained with the Virtual system were within 1°-2° from 0 with the head positioned at 0°, which is in agreement with many other studies of SVV with the head at 0° (Akin & Murnane, 2009; Halmagyi & Curthoys, 1999; Zwergal, Rettinger, Frenzel, Dieterich, & Strupp, 2009). Using the intraclass correlation coefficient, test-retest reliability of the Virtual system was excellent in the 45° left position and fair to good in the 45° right and 0° position. Test-retest reliability of the bucket test was poor in all head positions. CONCLUSIONS: The Virtual system is a more reliable measure of static SVV than the bucket test. Therefore, the Virtual system could be utilized as a screening device for utricular dysfunction in busy clinical settings.

Effect of Electrode Montage and Head Position on Air-Conducted Ocular Vestibular Evoked Myogenic Potential.

PURPOSE: The purpose of this investigation was to identify the optimal recording parameters for evoking the ocular vestibular evoked myogenic potential (oVEMP) using air-conduction stimuli. METHOD: Subjects were 17 otologically and neurologically intact adults (age: M = 24.18 years, SD = 1.91 years). The oVEMP responses were elicited using a 500-Hz tone burst air-conduction stimulus presented at an intensity of 95 dB nHL. The setting was a balance function laboratory that was part of a large tertiary care otology clinic. RESULTS: The oVEMP electrode montage and body position that yielded the largest oVEMP amplitude was the belly-tendon montage (Sandhu, George, & Rea, 2013), recorded with the subject in the sitting position. The N1 latency recorded with the belly-tendon montage was significantly shorter than that recorded for the infraorbital montage in both the sitting and supine positions. CONCLUSION: The belly-tendon recording montage with the subject sitting yields significantly larger oVEMP amplitudes and shorter N1 latencies than do traditional bipolar infraorbital recordings.

The effects of amplitude normalization and EMG targets on cVEMP interaural amplitude asymmetry.

OBJECTIVES: The purpose of this investigation was to determine whether the use of visual feedback of tonic electromyographic (EMG) activity, or the use of amplitude normalization techniques would reduce significantly the variability in cervical vestibular evoked myogenic potential (cVEMP) P13-N23 interaural amplitude asymmetry data in otologically and neurologically intact children and adults. DESIGN: There were 97 subjects, both pediatric and adult, from whom the authors recorded cVEMPs with and without the use of an EMG target and amplitude normalization techniques. The four conditions were: (1) conventional recording (condition 1), (2) conventional recording with an EMG target (condition 2), (3) same as condition 1, with the addition of postacquisition amplitude normalization techniques, and (4) same as condition 2, with the addition of postacquisition amplitude normalization techniques. The absolute peak to peak amplitude of positive-negative response (P13-N23), absolute latency of P13, and the left or right amplitude asymmetry of P13-N23 were measured. RESULTS: Neither P13-N23 amplitudes nor latencies, neither mean root mean square (RMS) of the full wave rectified EMG activity, nor the standard deviation of the RMS EMG activity differed significantly when subjects were, and were not, asked to ensure their tonic EMG activity exceeded a visual target (i.e., representing >50 µV RMS EMG). Amplitude normalization of the cVEMP waveforms failed to reduce significantly the variability in the amplitude asymmetry data. CONCLUSIONS: Activating the sternocleidomastoid muscle with the patient in a semirecumbent position, with head turned away from the stimulated ear and head elevated (i.e., an optimal activation technique) was sufficient to produce the highest amplitude cVEMPs with an acceptable amount of variability in subjects of all ages. Group data suggested that the use of visual targets and amplitude normalization routines did not reduce significantly the variability in cVEMP interaural amplitude asymmetry measures. However, in isolated cases amplitude normalization converted an "abnormal" cVEMP into a "normal" cVEMP although the reverse occurred as well, suggesting that these techniques may be beneficial for a subset of patients receiving a less than perfectly administered test procedure.