Search

Objective: To compare video head impulse test (vHIT) and caloric test efficacy in decompensated and compensated vertigo patients and to further investigate whether vHIT alone can be used as a diagnostic tool in vertigo. Methods: This study included 25 patients diagnosed with vertigo and without any previous history of vertigo or hearing loss before their admission to our clinic. The control group consisted of 16 healthy adult volunteers. Patients were classified into 2 groups, compensated and decompensated. Video head impulse test and caloric tests were performed and the results were compared between the groups. Results: The difference of caloric test values between control-compensated groups and compensated-decompensated groups was statistically significant (P <.001, Pearson χ2). However, there was no statistically significant difference between the compensated and control groups according to vHIT gain asymmetry values (P =.087). In the very early stages of the disease with spontaneous nystagmus, the diagnostic significance of vHIT was similar to that of the caloric test. When both sides were compared, vHIT gain asymmetry values were close to the caloric test asymmetry values. In the compensated stage, caloric test was superior to vHIT in differentiating compensated vestibular pathologies. When vHIT sensitivity was evaluated according to the bi-thermal caloric test results, the sensitivity of the vHIT gain asymmetry value was 85.71% and 23.08% for decompensated and compensated patients respectively. Conclusion: In the early decompensated stages of the disease with spontaneous nystagmus, vHIT shows similar diagnostic accuracy to that of the caloric test. Since patients can tolerate vHIT more easily, our results suggest that vHIT can be considered as a primary evaluation method in the early (decompensated) period of the disease and should be preferred over the caloric test during the acute phase. Caloric test is more reliable at the compensated stage. Video head impulse test is inadequate in evaluating the compensated vestibular hypofunctional states after compensation has been restored. Level of Evidence: Level 2b [ABSTRACT FROM AUTHOR]

Introduction: Many new objective tests to assess the function of specific structures of the vestibular organ are currently adopted in vestibular clinics. One of the objective assessments include the video head impulse test (vHIT) where gain & velocity responses of eye relative to the head movements are recorded using an infrared camera. Methods: Thirty normal hearing subjects age between 18 to 25 years old participated in this study. At least ten Lateral, Left Anterior Right Posterior (LARP), and Right Anterior Left Posterior (RALP) responses were recorded for each participant by making small and rapid unpredictable head movements. Results: The average velocity gain for Lateral responses at 40 ms, 60 ms and 80 ms were 1.05 ± 0.003, 1.03 ± 0.002 and 1.01 ± 0.003 respectively. The LARP average velocity regression were 1.01 ± 0.24 for Left Anterior and 1.05 ± 0.25 for Right Posterior, with an average gain asymmetry of 5.13%. The RALP average velocity regression were 1.08 ± 0.31 for Right Anterior and 1.12 ± 0.30 for Left Posterior, with an average gain asymmetry of 5.87%. One sample T-test were conducted to compare Lateral responses to a previous study by Mossman et al. (2015) where significant differences in velocity gain at 60 ms and 80 ms between studies were found where, t (59) = 5.56, p <0.01 and t (59) = 2.86, p < 0.01 respectively. Conclusion: This indicates the importance of establishing on -site norms for every clinical settings as techniques used and equipment differences could affect the results. [ABSTRACT FROM AUTHOR]

Since usefulness of power spectra (PS) analysis was demonstrated in many fields of electrophysiology, the aims of the present study were to evaluate differences in frequency domain values of eye velocity traces between a group of 60 healthy subjects (HC) and 35 matched superior vestibular neuritis (VN) patients and to determine prognostic aspects of such values in terms of superior VN recovery. PS calculated on video head impulse test traces was compared between HC and during the acute stage of vertigo (T1) and after 3 months (T2) in superior VN patients. A multiple regression and desirability model between Δ (T2gain - T1gain) vestibulo-ocular reflex (VOR) gain and five prognostic factors were employed. Significant PS differences within the 7.8-16.6 Hz domain were found between superior VN and HC. A significant negative correlation was found between the 7.8-16.6 Hz domain unitary PS value and Δ VOR gain (β = - 0.836). The desirability model depicted a cutoff value of the unitary PS equal to 1.82 in order to obtain a Δ VOR gain rate at least equal to 0.1. Present findings could be a further step for monitoring those superior VN patients with systemic risk factors and high risk of VOR incomplete recovery. Graphical abstract In the top left, healthy control (HC) and superior vestibular neuritis (VN) subjects were screened by means of video head impulse test. In the top right, significant differences in power spectra values were depicted within the 7.8-16.6 Hz domain when comparing the two groups of subjects. In the bottom center, the desirability model depicts a cutoff value of the power spectra equal to 1.82 in order to obtain a Δ vestibulo-ocular reflex gain rate at least equal to 0.1. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the lateralization value of video head-impulse test (vHIT) for the diagnosis of vestibulopathy and to analyze cases showing dissociated results with caloric test.Methods: In total, 19 healthy volunteers and 92 dizzy patients who underwent both a caloric test and a vHIT were enrolled. Patients were divided into two groups depending on their fluctuating pattern of vertigo. The vestibulo-ocular reflex (VOR) gain and gain asymmetry (GA) of a vHIT as well as unilateral weakness (UW) and the sum of the slow-phase velocities (SPVs) of warm and cold irrigation of the same side were compared. A cutoff value of VOR gain of a vHIT was also calculated using a receiver-operating characteristic curve.Results: A VOR gain in an affected ear and GA of a vHIT showed a statistically significant correlation with UW in a caloric test. The cutoff value of a vHIT was determined to be 0.875, derived under the assumption that UW of a caloric test ≤25% is normal. However, the parameters of the two tests were dissociated in 18%.Conclusion: A VOR gain of vHIT is a valuable objective parameter with a lateralization value determining vestibular hypofunction. However, considering substantial dissociation between a vHIT and a caloric test, these tests can be complementary tools for the lateralization of vestibular impairment for the comprehensive evaluation of patients' VOR. [ABSTRACT FROM AUTHOR]

Background/aims: Unsteadiness in the elderly is a frequent complaint and a strong predictor of falls and psychological distress. Although there is a general consensus that it is a multifactorial condition, recent studies have focused on the role of aging of the vestibular system as a possible cofactor. The aim of our work was to assess horizontal canal function in the elderly.Methods: We evaluated the gain of horizontal vestibulo-ocular reflex (VOR) with a video head impulse test on a sample of 58 subjects aged >70 years without lifetime episodes of vertigo and correlated the value with different clinical conditions (hypertension, diabetes, prior cardiovascular and vascular disorders of the central nervous system, and falls).Results: The mean value of the gain was 0.86 ± 0.12, and people aged between 70 and 80 years presented higher values (0.90 ± 0.1) compared to those >80 years (0.81 ± 0.13; p = 0.025). Previous vascular disorders of the central nervous system were a predictor of decreased VOR gain (p = 0.0003). A nonparametric analysis demonstrated that sex, age, and VOR gain (p ˂ 0.0001) were predictive of falls.Conclusions: Our data support the hypothesis of a decrease of VOR gain in the elderly. The decrease of canal function may therefore play a role in the risk of falls in the elderly. [ABSTRACT FROM AUTHOR]

• Placement of a hanger diagonally on the head rotates the head towards the hanger. • The mechanism underlying the hanger reflex (HR) is unknown. • We found an asymmetric reduction in the vestibular response during HR. • This inhibitory somatosensory-vestibular interaction may be a mechanism of HR. [ABSTRACT FROM AUTHOR]