The video head impulse test

Refractive Error Impact on Video Head Impulse Test Outcomes

OBJECTIVE

The objective of this study is to investigate the potential influence of refractive error on Video Head Impulse Test outcomes.

MATERIAL AND METHODS

Eighty-two patients were included in the study, and all patients underwent video head impulse testing. Patients were divided into four groups according to their refractive error: myopia, myopia-astigmatism, astigmatism, and emmetropia as control.

RESULTS

Patients with myopia are younger than patients with astigmatism and controls; similarly, patients with myopia-astigmatism are younger than patients with astigmatism. The right and left lateral, anterior, and posterior gain values were statistically significantly lower in the control group compared with myopia and myopia-astigmatism patients (p < 0.05). There was a statistically significant relationship between the right and left lateral, anterior, and posterior gain values and the degree of myopia in the patients (p < 0.05).

CONCLUSION

The results of the Video Head Impulse Test gain in myopia patients are higher than that in patients without refractive error. In addition, age may have an effect on gain values. It is important to consider this factor when evaluating the results of the Video Head Impulse Test in patients, and corrections should be made if necessary.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 2024.

Differentiation of peripheral and non-peripheral etiologies in children with vertigo/dizziness: The video-head impulse test and suppression head impulse paradigm

OBJECTIVES

To identify the etiology of vertigo/dizziness and determine the effectiveness of the video-head impulse test (vHIT) and the suppression head impulse paradigm (SHIMP) tests in distinguishing between peripheral and non-peripheral etiologies in children who presented to the otolaryngology department with complaints of vertigo/dizziness.

METHODS

The vHIT and SHIMP tests were applied to the children. The vestibulo-ocular reflex (VOR) gain and saccade parameters were compared.

RESULTS

In 27 children presenting with vertigo/dizziness, the most common etiological factor was inner ear malformation (IEM) (n = 6/27, 22.2%), followed by cochlear implant surgery (11.1%) and migraine (11.1%). Vestibular hypofunction was indicated by the vHIT results at a rate of 60% (9/15 children) and SHIMP results at 73.3% (11/15 children) among the children with a peripheral etiology, while these rates were 8.3% (1/12 children) and 25% (3/12 children), respectively, in the non-peripheral etiology group. SHIMP-VOR and vHIT-VOR gain values had a moderate positive correlation (p = 0.01, r = 0.349). While there were overt/covert saccades in the vHIT, anti-compensatory saccade (ACSs) were not observed in the SHIMP test (p = 0.041). The rates of abnormal vHIT-VOR gain (p = 0.001), over/covert saccades (p = 0.019), abnormal vHIT response (p = 0.014), ACSs (p = 0.001), and abnormal SHIMP response (p = 0.035) were significantly higher in the peripheral etiology group.

CONCLUSIONS

IEM was the most common etiological cause, and the rate of vestibular hypofunction was higher in these children with peripheral vertigo. vHIT and SHIMP are effective and useful vestibular tests for distinguishing peripheral etiology from non-peripheral etiology in the pediatric population with vertigo/dizziness. These tests can be used together or alone, but the first choice should be the SHIMP test, considering its short application time (approximately 4-5 min) and simplicity.

Video head impulse test in stroke: a review of published studies

Accurate and timely diagnosis of posterior circulation stroke in patients with acute dizziness is a challenge that can lead to misdiagnosis and significant harm. The present review sought to identify and describe published research on the clinical application of vHIT in posterior circulation stroke. vHIT, a portable device, has gained prominence in evaluating peripheral vestibular disorders and offers potential applications in diagnosing neurological disorders, particularly posterior circulation stroke. Several studies have shown that vHIT can differentiate between stroke and vestibular neuritis based on VOR gain values, with high sensitivity and specificity. The manuscript also discusses vHIT's performance in differentiating between types of posterior circulation stroke, such as PICA, AICA, and SCA strokes. While vHIT has demonstrated promise, the review emphasizes the need for further research to validate its use as a tool to rule out stroke in acute dizziness patients in the emergency department. In conclusion, the manuscript underscores the potential of vHIT as a valuable addition to the diagnostic arsenal for acute dizziness, particularly in the context of posterior circulation stroke. It calls for further research and wider adoption of vHIT in clinical settings to improve patient care and reduce unnecessary costs associated with misdiagnoses.

Video Head Impulse Test: A Comparison and Analysis of Three Recording Systems

The present study aimed to compare the efficacy and reproducibility of three existing systems in a group of healthy individuals for vHIT. A prospective randomized study was conducted on 12 healthy individuals. The vHIT tests were carried out. The values of the gains for the 3SCCs of each ear were collected using the three devices. The expected average gain of 1 was the gain standard. The statistical significance in the difference in gains were assessed. There is good reproducibility of the results of the vHIT examination. EyeSeeCam appeared to be the worst performing system with a slightly overstated average gain of 1.15. Otometrics has longest average examination time per patient. Synapsis is the system with the best quality/time invested and easiest to access. Video head impulse system depends on the examiner's preference, reproducible and superimposable depending on the examiner and experience.

Head and vestibular kinematics during vertical semicircular canal impulses

BACKGROUND

The video head impulse test (vHIT) is a common assessment of semicircular canal function during high-speed impulses. Reliability of the vHIT for assessing vertical semicircular canals is uncertain. Vertical head impulses require a complex head movement, making it difficult to isolate a single semicircular canal and interpret resulting eye rotations.

OBJECTIVE

The purpose of this study was to provide descriptive head kinematics and vestibular stimuli during vertical plane impulses to ultimately improve impulse delivery and interpretation of vHIT results for vertical semicircular canals.

METHODS

Six participants received right anterior (RA) and left posterior (LP) semicircular canal impulses. Linear displacements, rotational displacements, and rotational velocities of the head were measured. Peak velocities in semicircular canal planes and peak-to-peak gravitoinertial accelerations at the otolith organs were derived from head kinematics.

RESULTS

The largest rotational velocities occurred in the target semicircular canal plane, with non-negligible velocities occurring in non-target planes. Larger vertical displacements and accelerations occurred on the right side of the head compared to the left for RA and LP impulses.

CONCLUSIONS

These results provide a foundation for designing protocols to optimize stimulation applied to a singular vertical semicircular canal and for interpreting results from the vHIT for vertical semicircular canals.

The Role of Video Head Impulse Test (Vhit) in Diagnosing Benign Paroxysmal Positional Vertigo (BPPV)

Benign paroxysmal positional vertigo (BPPV) is a common clinical disorder characterized by brief recurrent spells of vertigo often brought about by certain head position changes. General treatment for BPPV is by clinical examination by Dix-Hallpike maneuver, Video head impulse test (VHIT) is a novel test that enhances diagnostic opportunities and enables a clinician to precisely localize the site of vestibular disorders. This interested us to investigate its potential in diagnosis of BPPV.The aim of the present study is to assess the role of Video head impulse test (VHIT) in confirming the clinically diagnosed case of BPPV.All patients above the age of 18 years who were clinically diagnosed with BPPV underwent VHIT and results were correlated with clinical findings. Total 60 patients were studied in the period of 2016-2018.Among the 60 patients clinically diagnosed with BPPV, 41 were males and 19 were females. Majority of patients were in the age group of 51-60 years. Posterior canal is most commonly affected (97%) than anterior and lateral canals in BPPV. In unilateral posterior canal BPPV and bilateral posterior canal BPPV VOR (Vestibulo- ocular reflex) gains was reduced but were not statistically significant. Saccades were present only in 17 cases. There is no relationship between the presence of saccades, the canal involved and the side of the lesion.From the present study we conclude that the currently available equipment for VHIT is not useful in diagnosing BPPV. Also, strongly recommends advanced research on this to record minute changes in VOR gain.

An Investigation of Sensorimotor Impairments in Individuals 4 weeks to 6 months following mild traumatic brain injury

OBJECTIVE

To identify whether adults 4 weeks to 6 months post mild traumatic brain injury (mTBI) have sensorimotor impairments when compared to healthy controls. A secondary aim was to determine if impairments were evident irrespective of participant perceived absence of symptoms.

DESIGN

Observational cohort study SETTING: Tertiary University and Hospital PARTICIPANTS: Participants included 113 individuals aged 18 to 60 years consisting of 39 controls with no prior concussion history, and 74 individuals, 4 weeks to 6 months post mTBI of which 35 considered themselves asymptomatic (Asymp), and 37 symptomatic (Symp).

MAIN OUTCOME MEASURES

Assessments of oculomotor, vestibulo-ocular reflex (VOR) control, balance, single and dual task tandem walk (TTW-S, TTW-D) and vestibular positional testing.

RESULTS

Poorer balance and tandem walk performance, and a higher frequency of positive oculomotor, VOR and vestibular positional tests were evident in the mTBI group compared to controls. In particular ≥ 2 positive oculomotor findings were evident in 53.7% of the participants with mTBI compared to 10.8 % of controls. The mTBI group who considered themselves recovered (Asymp) demonstrated significantly increased TWT-D time, and a higher proportion 53% had ≥ 2 positive oculomotor tests compared to controls.

CONCLUSION

Persistent sensorimotor impairments, particularly evidenced by disturbed oculomotor function and deficits in dual task tandem walking were identified among adults 4 weeks to 6 months post mTBI. These disturbances were evident regardless of whether ongoing symptoms were reported. The findings support recommendations for routine clinical assessment of sensorimotor function post mTBI with implications for injury prevention.

A possible objective test to detect benign paroxysmal positional vertigo. The role of the caloric and video-head impulse tests in the diagnosis

Background

Objectives

Methods

Results

Conclusion

Vestibular asthenopia

Vestibular asthenopia, analogous to visual asthenopia, is a sensory (or sensory-motor) discomfort consisting of a set of subjective symptoms, the expression of which is essentially visual and whose origin is a transient vestibular incident. It can be considered the result of a sudden global central disorder, such as a "computer glitch," following a chain of events in response to an initial vestibular disease, even minor and devoid of clinical signs. This disorder results in inadequate processing and imperfect integration of afferent visual and vestibular input, leading to ocular fatigue, pain associated with eye movement, and sensitivity to retinal slip.

Evaluation of the vestibular system in individuals with presbycusis using video head impulse test and videonystagmography

BACKGROUND

Vestibulo-ocular reflex (VOR) function is expected to be normal in patients with presbycusis during sudden head rotations.

AIM

This study aimed to determine whether presbycusis was accompanied by vestibular system pathologies. In addition, it was examined whether there was a difference existed between the patients with and without presbycusis in terms of normative data.

MATERIALS AND METHODS

A total of 40 individuals were included in the study: 20 in the presbycusis group and 20 in the control group. The vestibular systems of both groups were evaluated using the video head impulse test and videonystagmography.

RESULTS

The right and left lateral VOR gain values were decreased in the group with presbycusis compared to the control group. The difference between the two groups in the mean VOR gains in the right lateral canal and left lateral canal were statistically significant (p = .040 and p = .050, respectively). The air caloric tests of all individuals were found to be normal.

CONCLUSIONS

This result suggests that the loss of vestibular hair cells and vestibular nerve degeneration in the lateral semicircular canal may be more severe in presbycusis than in the same age group with normal hearing.

The Video Head Impulse Test in the acute stage of posterior canal benign paroxysmal positional vertigo

OBJECTIVE

Study the high-frequency vestibulo-oculomotor reflex in posterior canal benign paroxysmal positional vertigo (BPPV) through Video Head Impulse Test (vHIT).

METHODS

150 patients suffering for the first time from posterior canal BPPV were studied. Posterior canal vestibulo ocular reflex (VOR) gain was analysed through stimulations in right anterior-left posterior and left anterior-right posterior planes before treatment, immediately after resolution of the acute stage and one month later. Results were compared with a group of 100 healthy individuals.

RESULTS

No significant difference between the study the control groups was observed, except for normalised asymmetry ratio of the posterior canal which was significantly higher in the study group. VOR gains of both affected posterior canals and contralateral healthy posterior canals were not significantly correlated with the VOR gain of ipsilateral and contralateral anterior canals.

CONCLUSIONS

vHIT does not seem to represent an essential tool to study typical posterior canal BPPV in patients affected by this disease for the first time. Different results might be expected in relapsing forms, non-responsive forms, long lasting forms, or atypical variants in which major damage could be provoked by the persistence of otoconia in the canal or by its complete or partial jam.

Comparison of the effects of the temperature of intratympanic dexamethasone injections on vertigo

OBJECTIVE

This study aimed to compare if vertigo improved in patients when the dexamethasone used in the intratympanic (IT) injection was applied at body temperature or at room temperature.

METHODS

The study included 54 patients who had undergone intratympanic treatment due to sudden hearing loss and tinnitus. The IT injection was administered to all patients, 2 times with 1-day intervals. Two different IT injection techniques were used for each patient: injecting dexamethasone at room temperature and injecting it at body temperature. Patients were asked to report the vertigo they felt immediately, and at 15 min after the injection using the visual analogue scale (VAS) and the four-point categorical rating scale (CRS-4).

RESULTS

The level of vertigo immediately after injection was lower when the dexamethasone was injected at body temperature rather that at room temperature for both the VAS and CRS-4 (p < 0.05). However, no statistical differences in the VAS and CRS-4 self-report values between the two methods were found 15 min after the injection (p > 0.05).

CONCLUSION

Vertigo due to IT decreases within minutes. When the IT drugs are administered at body temperature, temporal vertigo due to injection is lower than when they are administered at room temperature.

Vestibular and Oculomotor Function in Children with Cerebral Palsy: A Scoping Review

Cerebral palsy (CP) is a nonprogressive permanent brain injury that causes an impairment of movement and posture. This scoping review aimed to answer the following questions: (1) "What is the status of oculomotor function in children with CP?" (2) "What is the status of vestibular function (i.e., gaze stability, perception of vertical, vestibular-related balance abilities) in children with CP?" Using Arksey's and O'Malley's five-stage framework, we searched six online databases for relevant articles. The inclusion criteria were: (1) participants of the studies included individuals with CP; (2) a primary outcome in the studies was measurement of oculomotor, vestibular, and/or balance; (3) studies were published within the past 20 years; and (4) the participants in the studies were between 0 and 21 years of age. Twenty-one articles were found that described impairments in oculomotor function ( n  = 9), vestibular function ( n  = 1), and oculomotor and vestibular integration ( n  = 11) in children with CP. The evidence suggests that children with CP may have altered saccadic and smooth pursuit eye movements, abnormal saccular function, poor eye-hand coordination, and abnormal use of vestibular information for balance. Future studies should explore peripheral and central vestibular function using reliable and valid methods for this population. This scoping review demonstrated a paucity of rigorous and objective research to describe the status of oculomotor and vestibular function in children with CP. However, preliminary studies suggest that more research is warranted.

Effect of Spatial Orientation of the Horizontal Semicircular Canal on the Vestibulo-Ocular Reflex

OBJECTIVE

To determine if an alignment of the horizontal semi-circular canal (hSCC) with the plane of rotation would enhance the vestibular-ocular reflex (VOR) gain result as it has been previously suggested.

STUDY DESIGN

Comparative study of a physiological vestibular function test in healthy subjects.

SETTING

Tertiary referral center for otology and neurotology.

PATIENTS

Twenty two healthy volunteers were recruited for this study. Their mean age was 25.6 years and the sex distribution was 14:8 (M:F). None of the subjects had a history of audiovestibular disorders.

INTERVENTION

The video Head Impulse Test (v-HIT) was performed with the hSCC in the conventional position (head upright, horizontal gaze) and also with the hSCC in-line with the earth horizontal.

MAIN OUTCOME MEASURES

depending on the alignment of the hSCC with the plane of head rotation.

RESULTS

There was no significant difference between the results, either for the VOR gain at 60 ms, or the regression slope gain, when the two alternative head positions were compared.

CONCLUSIONS

The data acquired in this study show that the VOR as measured by the v-HIT is not enhanced by aligning the plane of the hSCC with the plane of rotation during the testing procedure. Hence, we recommend that the positioning of the patient, with the head upright and a horizontal gaze direction should be routinely used in the clinical evaluation of the angular VOR by v-HIT.

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor

BACKGROUND AND PURPOSE

Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor.

METHODS

Twenty-eight patients (21 women; age=64±12 years, mean±SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification.

RESULTS

Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction.

CONCLUSIONS

Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

Relationship between video head impulse test (vHIT) and caloric test in patients with vestibular neuritis

INTRODUCTION AND OBJECTIVES

The caloric test is the gold standard for the loss of vestibular function diagnosis. The Video Head Impulse Test (vHIT) assesses the same reflex by using a video- assisted examination of the impulsive maneuver. We intend to compare the variation of results of the vHIT and the caloric test in patients with vestibular neuritis with respect to their initial condition at two different moments of their evolution and to check the level of correlation between them and with that of the DHI test

METHODS

We explored 20 patients with neuritis by using both vHIT and the caloric test on the same day. We assessed the correlation between these two tests and with the DHI test for each patient at two different moments of their evolution.

RESULTS

We calculated gain asymmetry and compared it with the canal paresis, but we found neither a linear correlation between them, nor a correlation between the DHI test or improvement of these two other tests. We conclude that the covert saccades maintain a similar speed whilst present in the VHIT, but the overts diminish their speed over time.

CONCLUSIONS

The VHIT and the caloric test show different responses of the vestibulo-ocular reflex, because they stimulate different frequencies of this reflex. No correlation was found between the VHIT, the caloric test and the DHI test. The tests appear to complement one another.