A new test of vestibular function, video head impulse testing (vHIT), evaluates function of the anterior and posterior vertical semicircular canals as well as the horizontal canals. Our goal was to collect normative data for vHIT in both horizontal and vertical planes. Horizontal data was compared to bithermal calorics. Data was collected from 19 participants with normal auditory function and no complaints regarding dizziness or balance. All occulomotor results were normal. Bithermal water caloric irrigations revealed an average unilateral weakness and directional preponderance of < 10%. For vHIT, average velocity gains (comparison of head velocity to compensatory eye velocity) were calculated for right lateral and left lateral maneuvers using instantaneous velocity measurements at 40, 60, and 80 ms and using the velocity regression measurement from 1-100 ms. Average instantaneous velocity gain at 60 ms was 1.175 for right lateral and 1.159 for left lateral. Average velocity regression gain (1-100 ms) was 1.147 for right lateral and 1.172 for left lateral, with an average gain asymmetry of 2.6%. The RALP average velocity gain, based on the velocity regression measurement from 1-100 ms, was 1.514 for right anterior and 1.665 for left posterior, with an average gain asymmetry of 7.26%. The LARP average velocity gain, based on the velocity regression measurement from 1-100 ms, was 0.923 for left anterior and 0.876 for right posterior, with an average gain asymmetry of 7.11%. Unlike with laterals, consistent vertical responses were more difficult to obtain. Contributing factors are camera slippage, inexperience, technique, and the constrained eye movement in the vertical plane.

The semicircular canals are involved in the coding of angular acceleration of the head and body. Presently, video-nystagmography (VNG) and specifically, caloric testing, is the gold standard for evaluation of semicircular canal function. Caloric irrigation via VNG can only evaluate horizontal semicircular canal function; with this test, there is no way to evaluate the function of the anterior and posterior vertical semicircular canals. The video Head Impulse Test (vHIT) is a relatively new protocol that has the capability to test the function of the horizontal, anterior vertical, and posterior vertical semicircular canals. Because the vHIT system is newly available to clinicians, there is a need to collect normative data, particularly for the vertical semicircular canals. For this study, data was collected from 12 participants with no complaint or history of balance difficulty. Additionally, we compared our data with normative data collected in an earlier study to determine consistency. Lateral average velocity gain measurements were consistent however, a comparison of RALP an LARP velocity gain measurements showed inconsistency.

The field of medicine is always evolving and one step in this evolution is the use of decision support systems like artificial intelligence. These systems open the possibility to minimize human error in diagnostics as practitioners can use objective measurements and analysis to assist with the diagnosis. In this study the focus has been to explore the possibility of using deep learning models to classify stroke, vestibular neuritis and control groups based on datafrom a video head impulse test (vHIT). This was done by pre-processing data from vHIT into features that could be used as input to an artificial neural network. Three different modelswere designed, where the first two used mean motion data describing the motion of the head and eyes and their standard deviations, and the last model used extracted parameters. The models were trained from vHIT-data from 76 control cases, 37 vestibular neuritis cases and 46 stroke cases. To get a better grasp of the differences between the groups, a comparison was made between the parameters and the mean curves. The resulting models performed to a varying degree with the first model correctly classified 77.8 % of the control cases, 55.6 % of the stroke cases and 80 % of the vestibular neuritis cases. The second model correctly classified 100 % of the control cases, 11.1 % of the stroke cases and 80.0 % of thevestibular neuritis cases. Lastly the third model correctly classified 77.8 % of the control cases, 22.2 % of the stroke cases and 100 % of the vestibular neuritis cases. The results are still insufficient when it comes to clinical use, as the stroke classification requires a higher sensitivity. This means that the cases are correctly classified and gets the urgent care they need. However, with more data and research, these methods could improve further and then provide a valuable service as decision support systems.

Background: The observation or measurement of eye movement can aid in the detection and localization of vestibular pathology due to the relationship between the function of the vestibular sensory receptors in the inner ear and the eye movements produced by the vestibulo-ocular reflex (VOR). The majority of bedside and laboratory tests of vestibular function involve the observation or measurement of horizontal eye movements (i.e., horizontal VOR) produced by stimuli that activate the horizontal semicircular canals (SCCs) and the superior vestibular nerve. The video head impulse test (vHIT) is a new clinical test of dynamic SCC function that uses a high-speed digital video camera to record head and eye movement during and immediately after passive head rotations. The SYNAPSYS Inc. vHIT device measures the “canal deficit” (deviation in gaze) during passive head impulses in the horizontal and diagonal (vertical) planes. There is, however, a paucity of data that has been reported using this device. Purpose: The purpose of this study was to obtain normative data and assess the test-retest reliability of the SYNAPSYS vHIT (version 2.0). Research Design: A prospective repeated measures design was utilized. Study Sample: Thirty young adults with normal hearing, normal caloric test results, and a negative history of vestibular disorder, neurological disease, open or closed head injury, or cervical spine injury participated in the study. Data Collection and Analysis: A single examiner manually rotated each participant’s head in the horizontal and diagonal planes in two directions (left and right in the horizontal plane; downward and upward in each diagonal plane) resulting in the stimulation of each of the six SCCs. Each participant returned for repeat testing to assess test-retest reliability. The effects of ear, session, and semicircular canal (horizontal, anterior, posterior) on the magnitude of canal deficit during the vHIT were assessed using repeated measures analysis of variance. Results: The mean canal deficit of the horizontal canals (8.3%) was significantly lower than the mean canal deficit of the anterior canals (16.5%) and the posterior canals (15.2%); there was no significant difference between the mean canal deficits of the anterior and posterior canals. The main effects of session and ear on canal deficit were not significant, and there were no significant interaction effects. There was no significant difference between the mean canal deficit for session 1 and session 2 for the horizontal, anterior, and posterior canals. The 95th percentiles for canal deficit were 19, 26, and 22% for the horizontal, anterior, and posterior SCCs, respectively. Conclusions: Testing of all six SCCs was completed in most participants in ∼10 min and was well-tolerated. The vHIT has some important advantages relative to more established laboratory tests of horizontal SCC function including the ability to assess the vertical SCCs, lower cost, shorter test time, greater portability, minimal space requirements, and increased patient comfort. Additional data, however, should be obtained from older participants with normal vestibular function and from patients with vestibular disorders. Within-subject comparisons between the results of the vHIT and the caloric and rotary chair tests will be important in determining the role of the vHIT in the vestibular test battery.

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