# Application of Video Head Impulse Test in the Diagnosis and Follow-Up of Vestibular Schwannoma: Case Series, Narrative Literature Review and Clinical Practice Implications

## TL;DR

This study explores how the video Head Impulse Test (vHIT) can help diagnose and monitor vestibular schwannoma patients before and after surgery.

## Contribution

The study introduces a detailed interpretation of vHIT, including visual analysis of vHIT curves, for vestibular schwannoma follow-up.

## Key findings

- Vestibular loss features varied among patients with vestibular schwannoma before treatment.
- Post-surgery, acute labyrinth denervation signs were prominent in early follow-ups.
- Central compensation features became more evident over time despite decreased vHIT gain.

## Abstract

Background/Objectives: Vestibular schwannoma (VS) is a benign cerebellopontine angle tumor causing audiological and vestibular symptoms. This pilot study aimed to describe the application of video Head Impulse Test (vHIT) in the diagnosis and follow-up of patients with unilateral VS treated surgically. The objective was to describe a detailed interpretation of vHIT—not only numerical parameters such as gain and corrective saccades, but also a visual analysis of vHIT curves. Methods: The results were presented in four cases for better understanding and more straightforward explanation. The patients underwent surgery through the middle cranial fossa and translabyrinthine approach. In each patient, vHIT examinations were performed preoperatively and at one month, three months, and one year after the surgery. Results: Before treatment, vestibular loss features varied within the presented cases. Findings of vestibulo-ocular reflex deficiency were most pronounced in the lateral semicircular canals. After the surgery, severe signs of acute labyrinth denervation were found during the first follow-up visit. Over time, features indicating central compensation became more pronounced, despite a decrease in gain in subsequent vHIT examinations. Conclusions: Detailed analysis of vHIT curves is crucial to analyze vestibulo-ocular reflex in patients with VS. Our preliminary data confirms that vHIT examination can be helpful in the postoperative follow-up assessment and compensation evaluation.