The video head impulse test

CONCLUSION

Additional research is needed to validate the importance of the video head impulse tests (vHIT), but it provides an important contribution to the evaluation of anterior and posterior semicircular canal disorders.

OBJECTIVES

To share observations of the vHIT test in clinical neurotology and to discuss the significance of the study findings.

METHODS

This study comprised 200 patients with a clinical history of vestibular disturbances who were submitted to a vHIT including all six semicircular canals.

RESULTS

Abnormal responses of the anterior and posterior canals were found in several patients, either alone or combined with altered responses in the lateral canals. A unilateral hypoactive response of a posterior canal was found in a patient with a small vestibular schwannoma.

Caloric stimulation and video-head impulse testing in Ménière's disease and vestibular migraine

CONCLUSION

Both the bithermal caloric test and the video-head impulse test (vHIT) were more often abnormal in Ménière's disease (MD) than in vestibular migraine (VM). Horizontal vestibulo-ocular reflex (hVOR) evaluation with caloric test (low-frequency test) was significantly more often abnormal than vHIT (high-frequency test). Therefore, both tests can be used in a complementary way for frequency-selective testing of peripheral vestibular function.

OBJECTIVES

To compare the results of caloric testing and vHIT in MD and VM and to determine which test is more sensitive to uncover peripheral vestibular hypofunction.

METHODS

Patients with MD (n=30) or VM (n=23) were examined with the caloric test and vHIT. The parameters analyzed were the canal paresis factor for the caloric test and the hVOR gain on both sides in vHIT.

RESULTS

The caloric test was abnormal in 67% of patients with MD and in 22% with VM (p=0.002), while the vHIT showed an hVOR deficit in 37% in MD and 9% in VM (p=0.025). In all, 28% of patients with an abnormal caloric test had a normal vHIT, whereas 6% of those with an abnormal vHIT had a normal caloric test. The sensitivity of vHIT compared with caloric testing was 55% for MD and 40% for VM. Neither the caloric test nor vHIT could detect significant differences between early (<5 years) or advanced stages (>5 years) of MD or VM.

Caloric test and video-head-impulse: a study of vertigo/dizziness patients in a community hospital

The head-impulse test (HIT) is an important test for examining unilateral vestibular hypofunction. The new video-head-impulse test (vHIT) is more sensitive and specific than the clinical bedside-head-impulse test (bHIT). Alternatively, one can test for vestibular hypofunction with the caloric irrigation test. Various studies showed that both tests may not always identify vestibular hypofunction; instead, the results of the tests might be contradictory. To evaluate the diagnostic value of these tests, we routinely measured patients exhibiting vertigo or dizziness at our community hospital with bithermal caloric irrigation, the bHIT and the vHIT. Only those patients (n = 172) with a pathological caloric irrigation test of more than 25 % unilateral weakness in the Jongkee's formula were included. Out of these patients, 41 % had a pathologic vHIT. Among the subgroup with acute symptoms (symptom onset within 5 days), 63 % had a pathological video-head-impulse, whereas only 33 % of the non-acute group (symptom onset more than 5 days) tested pathological. A pathological HIT depended on the disease stage, the amount of unilateral weakness in caloric examination and on the test itself.