Video Head Impulse Test to Preoperatively Identify the Nerve of Origin of Vestibular Schwannomas

AbstractBACKGROUNDIdentification of the nerve of origin in vestibular schwannoma (VS) is an important prognostic factor for hearing preservation surgery. Thus far, vestibular functional tests and magnetic resonance imaging have not yielded reliable results to preoperatively evaluate this information. The development of the video head impulse test (vHIT) has allowed a precise evaluation of each semicircular canal, and its localizing value has been tested for some peripheral vestibular diseases, but not for VS.OBJECTIVETo correlate patterns of semicircular canal alteration on vHIT to intraoperative identification of the nerve of origin of VSs.METHODSA total 31 patients with sporadic VSs were preoperatively evaluated with vHIT (gain of vestibule-ocular reflex, overt and covert saccades on each semicircular canal) and then the nerve of origin was surgically identified during surgical resection via retrosigmoid approach. vHIT results were classified as normal, isolated superior vestibular nerve (SVN) pattern, isolated inferior vestibular nerve (IVN) pattern, predominant SVN pattern, and predominant IVN pattern. Hannover classification, cystic component, and distance between the tumor and the end of the internal auditory canal were also considered for analysis.RESULTSThree patients had a normal vHIT, 12 had an isolated SVN pattern, 5 had an isolated IVN pattern, 7 had a predominant SVN pattern, and 4 had a predominant IVN pattern. vHIT was able to correctly identify the nerve of origin in 89.7% of cases (100% of altered exams).CONCLUSIONThe pattern of semicircular canal dysfunction on vHIT has a localizing value to identify the nerve of origin in VSs.

Download Full-text

Role of video head impulse test to indentify the site of lesion in patients with vestibular neuronitis

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20201276 ◽

2020 ◽

Vol 6 (4) ◽

pp. 669

Author(s):

Rabindra Bhakta Pradhananga ◽

Bigyan Raj Gyawali ◽

Bebek Bhattarai

Keyword(s):

Semicircular Canal ◽

Statistical Significance ◽

Neck Surgery ◽

Vestibular Nerve ◽

Head Impulse Test ◽

Video Head Impulse Test ◽

Institute Of Medicine ◽

Good Test ◽

Head Impulse ◽

Vestibular Neuronitis

Background: Vestibular neuronitis is one of the common causes of peripheral vertigo. Mostly the diagnosis of this entity is on clinical grounds. With the advent of video head impulse test (VHIT), assessment of function of all the semicircular canals has been possible based on principle of vestibulo-ocular reflex (VOR). The rationale of our study was to identify the affected branch of vestibular nerve in cases with clinical suspicion of vestibular neuronitis by measuring VOR gain and saccades using VHIT.Methods: This was a retrospective study carried out in the Department of ENT, Head & Neck Surgery of Institute of Medicine, Kathmandu, Nepal. Record files of patients who attended OPD between October 2017 to October 2018 with the clinical diagnosis of peripheral vestibular neuronitis were assessed. A total of 13 cases were included in the study. VHIT records of the cases were assessed for VOR gain and saccades. Normal contralateral canals were taken as control. Paired t-test was used to compare the statistical significance of gain asymmetry and presence of saccades between the affected side and normal side. Results: Of 13 cases, 11 had isolated involvement of lateral semicircular canal and 2 cases had isolated involvement of posterior semicircular canal. Average gain was 0.68 in both groups. Presence of overt and covert saccades was seen in all the affected canals.Conclusions: VHIT, in cases with vestibular neuronitis, is a good test not only to confirm the diagnosis but also to identify the division of vestibular nerve involved.

Download Full-text

Vestibular semicircular canal function as detected by video Head Impulse Test (vHIT) is essentially unchanged in people with Parkinson’s disease compared to healthy controls

Journal of Vestibular Research ◽

10.3233/ves-201626 ◽

2021 ◽

pp. 1-9

Author(s):

Kim E. Hawkins ◽

Elodie Chiarovano ◽

Serene S. Paul ◽

Ann M Burgess ◽

Hamish G. MacDougall ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Semicircular Canal ◽

Neurodegenerative Disorder ◽

Vestibular Function ◽

Head Impulse Test ◽

Healthy Controls ◽

Video Head Impulse Test ◽

Head Impulse ◽

Vestibulo Ocular Reflex

BACKGROUND: Parkinson’s disease (PD) is a common multi-system neurodegenerative disorder with possible vestibular system dysfunction, but prior vestibular function test findings are equivocal. OBJECTIVE: To report and compare vestibulo-ocular reflex (VOR) gain as measured by the video head impulse test (vHIT) in participants with PD, including tremor dominant and postural instability/gait dysfunction phenotypes, with healthy controls (HC). METHODS: Forty participants with PD and 40 age- and gender-matched HC had their vestibular function assessed. Lateral and vertical semicircular canal VOR gains were measured with vHIT. VOR canal gains between PD participants and HC were compared with independent samples t-tests. Two distinct PD phenotypes were compared to HC using Tukey’s ANOVA. The relationship of VOR gain with PD duration, phenotype, severity and age were investigated using logistic regression. RESULTS: There were no significant differences between groups in vHIT VOR gain for lateral or vertical canals. There was no evidence of an effect of PD severity, phenotype or age on VOR gains in the PD group. CONCLUSION: The impulsive angular VOR pathways are not significantly affected by the pathophysiological changes associated with mild to moderate PD.

Download Full-text