Does Catastrophizing Predict Response to Treatment in Patients With Vestibular Disorders? A Prospective Cohort Study.

OBJECTIVE: Determine levels of catastrophizing in patients with vestibular disorders and prospectively evaluate their relationship with patient-reported outcome measures. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary care neurotology vestibular disorders clinic. PATIENTS: Adult patients with various vestibular disorders. INTERVENTIONS: Patients were given the Dizziness Handicap Inventory (DHI) and the Dizziness Catastrophizing Scale (DCS) at a baseline visit and follow-up visit after treatment. MAIN OUTCOME MEASURES: Correlation studies were used to determine the relationships between DHI and DCS. Multivariable linear regression was performed to determine the relationship between DCS and DHI change with treatment, accounting for demographic variables. RESULTS: Forty-six subjects completed both the DHI and the DCS before and after treatment. Patients with higher baseline DCS scores had higher baseline DHI scores ( p < 0.001). There was a significant improvement in both DHI score ( p < 0.001) and DCS ( p < 0.001) at follow-up. Patients who had reduction in DCS scores during were more likely to show reduction in DHI scores ( p < 0.001). A subset of patients had a mindfulness-based stress reduction program included in their treatment. These patients had a greater reduction in both DCS and DHI scores at follow-up compared with those who received other treatments. CONCLUSIONS: Catastrophizing is associated with higher pretreatment DHI scores and worse treatment outcomes. Addressing dizziness catastrophizing may help improve vestibular outcomes.

Visually enhanced vestibulo-ocular reflex gain in patients with vestibular disease.

Objective: Vestibular migraine (VM) is a diagnostic challenge. Visually enhanced vestibulo-ocular reflex (VVOR) gain, a measure of the visual-vestibular interaction, has been proposed as a tool for diagnosing VM. This study seeks to evaluate VVOR gain's diagnostic capability to predict VM and to compare the phenotypes of vestibular patients with elevated versus normal/low VVOR gain. Methods: A retrospective review of consecutive adult patients at a dizziness clinic from October 2016 and December 2020 was conducted. VVOR gain's diagnostic performance was assessed with the area under the receiver operating characteristic (AUROC) analysis. Demographic factors and clinical presentations were compared between vestibular patients with elevated versus normal/low VVOR gain. Results: One hundred forty patients (70 with VM) were analyzed. VVOR gain was elevated in 68.6% of patients with VM, compared to 52.9% of patients without VM (p = .057). The AUROC of VVOR gain was 0.5902 (95% confidence interval: 0.4958-0.6846). Vestibular patients with elevated VVOR gain were younger than those with normal/low VVOR gain (mean age 50 vs. 62, p < .0001). A higher proportion of subjects with elevated VVOR gain had symptoms triggered by certain foods (17.6% vs. 5.5%, p = .040) and experienced sound sensitivity (34.1% vs. 18.2%, p = .040) and motion sensitivity (23.5% vs. 9.1%, p = .041). A greater proportion of VM patients with elevated VVOR gain were triggered by certain foods (27.1% vs. 0%, p = .006). Conclusion: VVOR gain alone has limited ability to discriminate VM from other vestibular conditions and must be interpreted carefully. VVOR gain elevation may be associated with food triggers and motion and sound sensitivity. Level of Evidence: IV.

VM-PATHI Correlates With Cognitive Function Improvement After Successful Treatment in Patients With Vestibular Migraine.

OBJECTIVE: To assess changes in cognitive function in vestibular migraine patients undergoing treatment. STUDY DESIGN: Prospective cohort. SETTING: Single-institution tertiary-care center. PATIENTS: Thirty-four patients with vestibular migraine were included in the study. Average age at diagnosis was 47.9 years. A majority of patients (91.2%) were female. INTERVENTIONS: Vestibular therapies included pharmacologic treatment (67.6%), mindfulness-based stress reduction (58.8%), vestibular physical therapy (20.6%), and lifestyle changes only (2.9%). MAIN OUTCOME MEASURES: Pretreatment and posttreatment questionnaires were collected including the Cognitive Failures Questionnaire (CFQ), Vestibular Migraine Patient Assessment Tool and Handicap Inventory (VM-PATHI), and Dizziness Handicap Inventory. RESULTS: Median time between pretreatment and posttreatment questionnaire was 4.4 months (range, 2.8-15.6. mo). CFQ scores decreased in subjects who responded to treatment, as defined by those with a positive change in VM-PATHI score (average decrease, 6.5; p = 0.03). CFQ scores did not improve in subjects who had no improvement in their vestibular condition, as defined by no change or an increase in VM-PATHI score (average increase, 2.0; p = 0.53). Univariate linear regression showed that VM-PATHI score change was highly predictive of CFQ change ( p < 0.01, r2 = 0.36). Multivariate regression demonstrated that the VM-PATHI ( p = 0.03) and not the Dizziness Handicap Inventory ( p = 0.10) predicted changes in CFQ score. CONCLUSIONS: Self-reported cognitive dysfunction improves with successful treatment of vestibular migraine.

Recent Developments in Vestibular Migraine: A Narrative Review.

PURPOSE: The aim of this study was to review current literature regarding the epidemiology of vestibular migraine (VM), patient presentation, pathogenesis, and treatment. RECENT FINDINGS: VM is becoming an increasingly recognized condition in the United States, currently affecting 2.7% of people. Patients may experience vestibular symptoms, such as vertigo and imbalance, with or without other migrainous symptoms. Recent evidence has also shown that patients with VM are at higher risk for cochlear dysfunction, such as sudden deafness, sensorineural hearing loss, and tinnitus. The heritability and genetics are not well understood, and the pathogenesis may involve calcitonin gene-related peptide, which is also implicated in migraine headaches. A disease-specific patient reported outcome measure, the Vestibular Migraine Patient Assessment Tool and Handicap Inventory, was recently developed and validated. A limited number of controlled trials have assessed various therapies for VM, including triptans and beta-blockers. More data are needed to understand whether or not currently available migraine treatments are effective for VM. SUMMARY: VM is a common etiology of vertigo and dizziness, presenting with a characteristic spectrum of symptoms. Early data suggest that migraine treatments may be helpful in some cases.

Vestibular Migraine: Cognitive Dysfunction, Mobility, Falls.

OBJECTIVE: Recent evidence has shown that vestibular migraine is strongly associated with cognitive difficulties. However, limited data exist on real-world effects of that dysfunction. The objective of this study is to understand the epidemiology of cognitive dysfunction with vestibular migraine and associated sequelae using National Health Interview Survey data. STUDY DESIGN: Randomized, population-based survey study of US adults. SETTING: We generated a case definition approximating probable vestibular migraine based on Bárány Society criteria and validated that definition in a tertiary care vestibular clinic. PATIENTS: Adult respondents to the 2016 NHIS, which queries a representative sample of the civilian, noninstitutionalized US population. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: We evaluated incidence of self-reported cognitive dysfunction with vestibular migraine and whether individuals were more likely to have impaired mobility, falls, and work absenteeism than those without either condition. RESULTS: Among individuals with vestibular migraine, 40% reported "some" and 12% reported "a lot" of difficulty thinking versus 13% and 2% of those without vestibular migraine, respectively. Vestibular migraine sufferers were more likely to have difficulty thinking or remembering compared with respondents without dizziness (odds ratio, 7.43; 95% confidence interval, 6.06-9.10; p < 0.001) when controlled for age, sex, education, stroke, smoking, heart disease, and diabetes. Individuals with both vestibular migraine and cognitive dysfunction had fivefold increased odds of falls and 10-fold increased odds of mobility issues compared with those without either condition. Furthermore, individuals with both vestibular migraine and cognitive dysfunction missed 12.8 more days of work compared to those without either condition. CONCLUSION: Our findings indicate vestibular migraine is not only associated with cognitive dysfunction, but they are together associated with mobility issues, fall risk, and work absenteeism.

Effect of conventional transcranial direct current stimulation devices and electrode sizes on motor cortical excitability of the quadriceps muscle.

BACKGROUND: There is a growing concern among the scientific community that the effects of transcranial direct current stimulation (tDCS) are highly variable across studies. The use of different tDCS devices and electrode sizes may contribute to this variability; however, this issue has not been verified experimentally. OBJECTIVE: To evaluate the effects of tDCS device and electrode size on quadriceps motor cortical excitability. METHODS: The effect of tDCS device and electrode size on quadriceps motor cortical excitability was quantified across a range of TMS intensities using a novel evoked torque approach that has been previously shown to be highly reliable. In experiment 1, anodal tDCS-induced excitability changes were measured in twenty individuals using two devices (Empi and Soterix) on two separate days. In experiment 2, anodal tDCS-induced excitability changes were measured in thirty individuals divided into three groups based on the electrode size. A novel Bayesian approach was used in addition to the classical hypothesis testing during data analyses. RESULTS: There were no significant main or interaction effects, indicating that cortical excitability did not differ between different tDCS devices or electrode sizes. The lack of pre-post time effect in both experiments indicated that cortical excitability was minimally affected by anodal tDCS. Bayesian analyses indicated that the null model was more favored than the main or the interaction effects model. CONCLUSIONS: Motor cortical excitability was not altered by anodal tDCS and did not differ by devices or electrode sizes used in the study. Future studies should examine if behavioral outcomes are different based on tDCS device or electrode size.

Evaluation of motor cortical excitability using evoked torque responses: A new tool with high reliability.

BACKGROUND: Motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) are typically recorded via surface electromyography (EMG). However, another suitable alternative may be recording torque output associated with MEPs, especially when studying multiheaded muscles (e.g. quadriceps) for which EMG may not be ideal. METHODS: We recorded the motor evoked torque elicited by TMS along with conventional EMG-based MEPs (MEPEMG) over a range of TMS intensities (100-140 % of active motor threshold [AMT]) from twenty healthy young adults on two different days. MEPs were normalized using different normalization procedures (raw, normalized to maximum voluntary isometric contraction [MVIC], and peak MEP). Additionally, motor evoked torque was normalized to TMS-evoked peripheral resting twitch torque. Intraclass correlation coefficients (ICCs) were determined for each of these variables to compute reliability. RESULTS: Motor evoked torque showed good to excellent reliability (ICC: 0.65-0.90) at TMS intensities ≥ 110 % AMT, except when normalized by peak MEP. The reliability of raw MEPEMG and MVIC normalized MEPEMG was fair to excellent only at ≥ 130 % AMT (ICC: 0.42-0.82) and at ≥ 120 % AMT (ICC: 0.41-0.83), respectively. The reliability of both MEPEMG and motor evoked torque generally increased with increasing TMS intensities, with motor evoked torque normalized to the resting twitch torque yielding the best ICC scores. COMPARISON WITH EXISTING METHODS: When compared with conventional MEPEMG, motor evoked torque offers superior and reliable estimates of corticospinal excitability, particularly when normalized to resting twitch torque. CONCLUSIONS: TMS-induced motor evoked torque can reliably be used to measure corticospinal excitability in the quadriceps muscles.