The objective of this retrospective study was to investigate the horizontal vestibulo-ocular reflex (hVOR) pathway with caloric test (low-frequency hVOR) and video head impulse test (vHIT) (high-frequency hVOR) in patients with sporadic vestibular schwannoma (69 patients, 27-86 years, mean age 58.1 years) and to compare both test methods in terms of their sensitivity and specificity to detect a retrocochlear lesion. Test results with a unilateral weakness (UWCaloric) >25 % (caloric test) or a Mean-GainvHIT <0.79/asymmetry ratio of Gain (AR-GainvHIT) >8.5 % and accompanied refixation saccades (vHIT) were considered abnormal. The overall sensitivity of the caloric test was 72 %. The evaluation of AR-GainvHIT detected more abnormal cases than did Mean-GainvHIT (44 vs. 36 %). In up to 4 %, a normal caloric test result was related to an abnormal vHIT. There was only a moderate correlation of UWCaloric and AR-GainvHIT (r = 0.54, p < 0.05) with a linear regression line intercept/slope of 32.2/0.9 (p < 0.05). Receiver operating characteristics curve analysis exhibited at a UWCaloric of 50 % a vHIT sensitivity/specificity/positive predictive value/negative predictive value of 0.45/0.9/0.94/0.42. Vestibular testing at varying frequencies provides deeper insights into hVOR function and is helpful in detecting a cerebello-pontine lesion. Whereas caloric test yields a high sensitivity for nerve dysfunction, vHIT test reveals a remaining function of hVOR in the high-frequency range.

Audiological outcome after vibroplasty depends on the coupling efficiency reflected by the vibroplasty threshold.

The video head impulse test (vHIT) is a new method for investigating vestibular function that is currently poorly studied in terms of its value for clinical diagnosis in otolaryngology. Both the caloric irrigation and vHIT serve to evaluate the horizontal vestibulo-ocular reflex. In the present study, caloric irrigation and vHIT were compared in 46 patients with vestibular schwannoma. Caloric irrigation exhibits a higher sensitivity than vHIT (72% versus 41%) and both tests show only a moderate correlation. Tumor size and hearing level was significantly correlated with caloric abnormalities but not with vHIT findings. Since caloric irrigation and vHIT measure the hVOR in low and high frequency ranges, respectively, these tests have to be considered complementary and are valuable in both diagnostics and therapeutic decisions.

By means of the vHIT it is possible to obtain a side-specific and quantitative assessment of hVOR. Video-head impulse test is a reliable tool for vestibular testing even in bedside examinations of patients suffering from dizziness.

We report on a case with severe facial nerve stimulation via a cochlea‐facial nerve dehiscence that was most likely the result of prolonged occlusive hydrocephalus. The successful treatment of this adverse effect demonstrates for the first time its complete resolution using a multi‐mode grounding and monophasic passive discharge stimulation.