Are gain values significantly altered by manual data selection when performing the video Head Impulse Test (v-HIT) on all six semicircular canals with two different v-HIT systems.

BACKGROUND: It has not yet been tested whether averaged gain values and the presence of pathological saccades are significantly altered by manual data selection or if data selection only done by the incorporated software detection algorithms provides a reliable data set following v-HIT testing. OBJECTIVE: The primary endpoint was to evaluate whether the averaged gain values of all six SCCs are significantly altered by manual data selection with two different v-HIT systems. METHOD: 120 subjects with previously neither vestibular nor neurological disorders underwent four separate tests of all six SCCs with either EyeSeeCam® or ICS Impulse®. All v-HIT test reports underwent manual data selection by an experienced ENT Specialist with deletion of any noise and/or artifacts. Generalized estimating equations were used to compare averaged gain values based on unsorted data with averaged gain values based on the sorted data. RESULTS: EyeSeeCam®: Horizontal SCCs: The estimate and the p-value (shown in parenthesis) for the right lateral SCC and the left lateral SCC were 0.00004 (0.95) and 0.00087 (0.70) respectively. Vertical SCCs: The estimate varied from -0.00858 to 0.00634 with p-values ranging from 0.31 to 0.78. ICS Impulse®: Horizontal SCCs: The estimate and the p-value for the right lateral SCC and the left lateral SCC were 0.00159 (0.18) and 0.00071 (0.38) respectively. Vertical SCCs: The estimate varied from 0.00217 to 0.01357 with p-values ranging from 0.00 to 0.17. Based upon the averaged gain value from the individual SCC being tested, 148 tests before and 127 after manual data selection were considered pathological. CONCLUSION: None of the two v-HIT systems revealed any clinically important effects of manual data selection. However, 21 fewer tests were considered pathological after manual data selection.

Treatment of Benign Paroxysmal Positional Vertigo with the TRV Reposition Chair.

OBJECTIVES: The primary objective of this study was to evaluate how successful the reposition of retractable benign paroxysmal positional vertigo (BPPV) was when treating patients with the Thomas Richard Vitton (TRV) reposition chair. MATERIALS AND METHODS: This is a prospective clinical trial. A total of 81 BPPV patients who were referred to the tertiary Balance - Dizziness Centre at the Department of Otolaryngology, Head - Neck Surgery and Audiology, Aalborg University Hospital, Denmark were included and analyzed. All the patients were diagnosed and treated with the TRV reposition chair. RESULTS: The patients were successfully treated after an average of 2.23 (± 1.66 SD) treatments with the TRV reposition chair. There was a significant difference between the number of treatments needed in the single semicircular canal group and the multicanal group. Seventeen (22.6%) of the patients experienced either dislocation of otoconia, relapse, or new onset of BPPV during the trial period. The number of patients with BPPV located to the anterior, lateral, and multiple semicircular canals in this study was significantly higher than that in similar studies. Six patients (7.4%) were classified as treatment failures. CONCLUSION: We found the TRV reposition chair to be very successful in the diagnostics and treatment of patients with retractable and atypical BPPV. However, 7.4% experienced treatment failure.

Comparison of test results from two separate video head impulse test systems in a cohort of patients diagnosed with a unilateral vestibular schwannoma.

PURPOSE: Video head impulse testing (vHIT) is a relatively new technology enabling evaluation of vestibular function. The aim of this study was to compare the test results from two separate vHIT systems in a group of patients diagnosed with a unilateral vestibular schwannoma (VS) with regards to sensitivity, specificity and inter-examiner differences. METHODS: Forty-two patients were examined with two separate vHIT systems: EyeSeeCam® (system A) and ICS Impulse® (system B), by one of two examiners. All six semicircular canals (SCCs) were tested under standardized conditions, and strict criteria were set up for post-test interpretation. RESULTS: With the majority of test parameters, the two test systems were in agreement. Vestibular deficits were found in 40.5% (system A) to 45% (system B) of patients with a VS on the tested side; corresponding to a positive predictive value (PPV) of 86.4% (system B) to 94.4% (system A). The specificity was 97.6% for system A and 92.9% for system B. An overall agreement between the two vHIT systems measured as kappa was computed to be 0.61. There were no significant inter-examiner differences. When testing the vertical SCCs, a tendency of too high mean gain values was seen with system A but not with system B. CONCLUSION: In patients with unilateral VS, vHIT is a test with moderate sensitivity and high specificity in regard to identification of a vestibular deficit. There were no significant differences in test results between the two vHIT systems.

Intra- and Interexaminer Variability of Two Separate Video Head Impulse Test Systems Assessing All Six Semicircular Canals.

OBJECTIVE: To evaluate intra- and interexaminer variability of the video Head Impulse Test (v-HIT) when assessing all six semicircular canals (SCCs) of two separate v-HIT systems. STUDY DESIGN: Prospective study. SETTING: Department of Otolaryngology, Head and Neck Surgery, Aalborg University Hospital, Denmark. PATIENTS: One hundred twenty healthy subjects. INTERVENTION: Four separate tests of all six SCCs with either system A or system B. Two examiners tested all subjects twice. Pretest randomization included type of v-HIT system, order of paired SCC testing, as well as initial examiner. MAIN OUTCOME MEASURE: Gain values and the presence of pathological saccades were registered. Ninety-five percent limits of agreement (LOAs) were calculated for both intra- and interexaminer variability. Adding or subtracting the value from the mean difference achieves the upper and lower bound LOA. Ninety-five percent of the differences lie within these limits. RESULTS: Interexaminer reliability: System A: LOAs between 0.13 and 0.24 for the horizontal SCCs and between 0.42 and 0.74 for the vertical SCCs. System B: LOAs between 0.09 and 0.13 for the horizontal SCCs and between 0.13 and 0.20 for the vertical SCCs. Intraexaminer reliability: System A: LOAs were 0.19 and 0.14 for the horizontal SCCs and varied from 0.43 to 0.53 for the vertical SCCs. System B: LOAs were 0.14 for the horizontal SCCs and varied from 0.13 to 0.22 for the vertical SCCs. CONCLUSION: Horizontal SCC testing: both v-HIT systems displayed good intra- and interexaminer variability. Vertical SCC testing: System B displayed good intra- and interexaminer variability whereas the opposite was true with system A.