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BACKGROUND: Hyperventilation-induced nystagmus test (HINT) is capable of generating a response in 77.2% of cases of acute unilateral vestibulopathy (AUVP); both nystagmus toward the affected side (excitatory pattern) and toward the healthy side (inhibitory pattern) have been described. The aim of the study is to investigate the clinical and prognostic role of the test by evaluating its correlation with vestibulo-ocular reflex (VOR) gain. METHODS: We evaluated 33 AUVP patients by performing the HINT and video head impulse test (V-HIT) during the acute phase and then at 15 and 90 days after the onset of the symptoms. The correlation between the VOR gain of the affected side and test responses was evaluated first, phase by phase, and then considering the pattern shown during the first assessments. RESULTS: Patients with a negative HINT had a higher mean VOR gain than patients with a positive test at both 15 and 90 days. Patients who showed an inhibitory pattern at the first assessment had a continuous improvement in V-HIT performance, while patients with an initial excitatory response had a transient decrease in gain at the subsequent evaluation (P=.001). No difference between these 2 groups emerged at 90 days (P=.09). CONCLUSION: The finding of a negative HINT during the follow-up correlates with good V-HIT performance and could be an indicator of good recovery. The inhibitory pattern is associated with a subsequent improvement; and it would be indicative of compensation. but, despite this, the prognostic value of the test is limited [ABSTRACT FROM AUTHOR]

BACKGROUND: The aim of this study is to compare the possible functional involvement of the vestibulo-ocular reflex in the follicular and luteal phases. METHODS: The research was carried out at a university located in eastern Turkey. The study included 37 healthy female volunteering students aged 18-25 years. The functional head impulse test was applied twice in the follicular phase and in the luteal phase, and the results in both phases were compared. RESULTS: In the functional head impulse test, statistically significant differences were obtained between the follicular phase and the luteal phase at the stimulus to the lateral semicircular canal direction total and 6000°/s² acceleration percentage of correct answers values, the posterior semicircular canal direction stimulations at 3000°/s² and 5000°/s² acceleration percentage of correct answers values, and the anterior semicircular canal direction stimulations at 5000°/s² acceleration percentage of correct answers values. CONCLUSION: In the luteal phase, which corresponds to the period before menstruation, the vestibulo-ocular reflex is functionally negatively affected. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) presents an unpredictable and uneven clinical development of cerebellar ataxia, neuropathy, and vestibular areflexia. The aim of this study is to report the variability of vestibular test results in genetically confirmed patients with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome. METHODS: Caloric testing, video head impulse test (vHIT), and rotatory chair testing were performed in 7 patients who presented pathogenic repeat expansions in the replication factor complex unit 1 gene related to cerebellar ataxia, neuropathy, and vestibular areflexia syndrome. RESULTS: Reduced vestibulo-ocular reflex (VOR) gain was observed in 100% of the patients in rotatory chair testing. Three of them had bilateral areflexia in caloric testing while 2 showed unilateral hypofunction and 2 had no alterations in the test. Only 1 patient had bilateral abnormal vHIT with gains under 0.6 in both ears. CONCLUSION: Genetic testing allows an early diagnosis of cerebellar ataxia, neuropathy, and vestibular areflexia syndrome, whereby the vestibular system may be affected to different degrees. Rotatory chair testing has a higher sensitivity for the detection of vestibular hypofunction in these patients. Caloric testing can provide additional information. vHIT might underdiagnose patients with mild-to-moderate vestibulopathy. [ABSTRACT FROM AUTHOR]

BACKGROUND: The suppression head impulse test is a new paradigm of the head impulse test, recently introduced for clinical use. The aim of this study was to assess the importance of the suppression head impulse paradigm in evaluating vestibular function. METHODS: This comparative study was conducted from June 2020 to June 2022. The ears of the participants were divided into 2 groups: (i) ears with vestibular weakness and (ii) healthy controls. All participants underwent video head impulse tests at the time of presentation with both conventional head impulse paradigm and suppression head impulse paradigm, performed by the same examiner. The results of the 2 tests were compared, and the correlation between the corresponding parameters obtained (vestibulo-ocular reflex gain and saccades) was examined. RESULTS: Ninety-five participants were included in the study (190 ears) with a mean age of 42.2 ± 12.6 years. Forty-six ears had vestibular weakness, and 144 were healthy controls. The suppression head impulse paradigm test showed a significantly lower vestibulo-ocular reflex gain than the head impulse paradigm in both groups. A positive correlation emerged between the vestibulo-ocular reflex gain measured with both paradigms. Regarding the saccades, a negative correlation was observed between the overt saccades latency and amplitude measured with both paradigms. CONCLUSION: The new suppression head impulse paradigm complements the head impulse paradigm for a better evaluation of the vestibular function. The inconsistency of covert saccades in suppression head impulse paradigm makes it superior to head impulse paradigm in measuring vestibulo-ocular reflex gain, especially in patients with vestibular loss. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study investigates the test-retest reliability, aging effects, and differences in horizontal semicircular canals gain values between the head impulse paradigm and suppression head impulse paradigm. METHODS: Sixty healthy adult subjects aged 22-76-year-old (mean ± standard deviation = 47.27 ± 18.29) participated in the head impulse paradigm and suppression head impulse paradigm using the video head impulse test. The Head impulse paradigm was used to assess all 6 semicircular canals, while suppression head impulse paradigm measured only the horizontal canals. Twenty subjects aged 22-40-year-old (25.25 ± 4.9) underwent a second session for the test-retest reliability. RESULTS: There were good test-retest reliability for both measures (right horizontal head impulse paradigm, intraclass correlation coefficient = 0.80; left horizontal head impulse paradigm, intraclass correlation coefficient = 0.77; right anterior head impulse paradigm, intraclass correlation coefficient = 0.86; left anterior head impulse paradigm, intraclass correlation coefficient = 0.78; right posterior head impulse paradigm, intraclass correlation coefficient = 0.78; left posterior head impulse paradigm, intraclass correlation coefficient = 0.75; right horizontal suppression head impulse paradigm, intraclass correlation coefficient = 0.76; left horizontal suppression head impulse paradigm, intraclass correlation coefficient = 0.79). The test-retest reliability for suppression head impulse paradigmanti-compensatory saccade latency and amplitude were moderate (right latency, intraclass correlation coefficient = 0.61; left latency, intraclass correlation coefficient = 0.69; right amplitude, intraclass correlation coefficient = 0.69; left amplitude, intraclass correlation coefficient = 0.58). There were no significant effects of age on head impulse paradigm and suppression head impulse paradigm vestibulo-ocular reflex gain values and suppression head impulse paradigmsaccade latency. However, the saccade amplitude became smaller with increasing age, P < .001. The horizontal suppression head impulse paradigm vestibuloocular reflex gain values were significantly lower than the head impulse paradigm for both sides (right, P = .004; left, P = .004). CONCLUSION: There was good test-retest reliability for both measures, and the gain values stabilized with age. However, suppression head impulse paradigm anti-compensatory saccade latency and amplitude had lower test-retest reliability than the gain. The suppression head impulse paradigm vestibulo-ocular reflex gain was lower than the head impulse paradigm and its anti-compensatory saccade amplitude reduced with increasing age. [ABSTRACT FROM AUTHOR]

The central vestibular compensation reduces vestibular symptoms and helps individuals improve balance affected by vestibular dysfunction. The video head impulse test provides an opportunity to study central vestibular compensation objectively. This study aims to methodically present existing information about the video head impulse test as a measure to evaluate central vestibular compensation in patients with unilateral vestibular dysfunction. Literature review comprised 12 research articles selected based on pre-set criteria and timeline (January 2010 to June 2020). The findings indicate that the appropriate video head impulse test measures to evaluate central vestibular compensation after the occurrence of temporary unilateral vestibular dysfunction are the improvement in vestibulo-ocular reflex gain. And, for permanent unilateral vestibular dysfunction are reduction in catch-up saccades percentage, velocity, amplitude, latency, and Perez and Rey score. [ABSTRACT FROM AUTHOR]