Evaluation of Vestibular Function in Diagnosis of Vestibular Schwannomas

Functional Outcome and Balance Compensation in Patients with Unilateral Vestibular Schwannoma After Surgical Treatment-Short- and Medium-Term Observation

Objective: The aim was to evaluate vestibular function in patients with unilateral vestibular schwannoma before and in the short and medium term after surgical treatment to analyze vestibular compensation. The identification of the prognostic factors determining incomplete and slower balance recovery was assessed. Methods: Forty-five patients with unilateral vestibular schwannoma treated surgically through the middle cranial fossa and translabyrinthine approach were enrolled in this study. The data were collected in the period between April 2022 and August 2023. The clinical data, vestibular tests (video head impulse test, sensory organization test) and the dizziness handicap inventory (DHI) before and after surgery were evaluated. Results: One month after surgery, a temporary deterioration in the DHI results occurred (DHI total score before surgery 24.36 vs. one month after surgery 31.64); however, a significant increase was found only by analyzing the functional subscale (p = 0.0395) for the DHI functional, emotional and physical subscale results; in addition, the total score before and three months after the surgery did not differ significantly. No statistically significant differences between the preoperative sensory organization test and the test one month after the surgery were found, while a significant improvement in the vestibular parameters was observed three months after the surgery compared to the preoperative results (C5 0.0306, C6 0.0002, VEST 0.0294, COMP 0.0023). A negative correlation was found between the DHI total score and C5 (-0.3198, -0.3266), C6 (-0.3448, -0.46379), VEST (-0.3100, -0.3252) and COMP (-0.4018, -0.4854) one and three months after the surgery, respectively. A significant deterioration was found between the LSC gain results on the tumor side (p < 0.001) and on the healthy side before the surgery vs. one month afterwards (p = 0.0079) and before the surgery vs. three months afterwards (p = 0.0419). The middle cranial fossa or translabyrinthine approach had no influence on the postoperative results. Conclusions: In the postoperative period, vestibular compensation occurs spontaneously. The results show that the functional level deteriorates one month after surgery but then improves significantly three months after the surgery, which confirms that compensation occurs gradually. The DHI functional subscale results before surgery and three months afterwards did not differ significantly, which demonstrates that functional recovery after vestibular denervation should take place within that time. In the present study, no predictive factors for unsatisfactory functional postoperative outcomes were found.

A Proposal for Comprehensive Audio-Vestibular Test Battery Protocol for Diagnosis and Follow-Up Monitoring in Patients with Vestibular Schwannoma Undergoing Surgical Tumor Removal

Background: A vestibular schwannoma (VS) is a benign tumor, causing audiological and vestibular symptoms. This study aimed to propose a comprehensive audio-vestibular test battery protocol for diagnosis and follow-up monitoring in patients with unilateral VSs undergoing surgical removal. Methods: The detailed interpretation of audiological and vestibular findings was presented in two example cases. The surgery was performed through the middle cranial fossa (#1) and translabyrinthine approach (#2). The participants were evaluated with tonal, speech, and impedance audiometry, ABR, caloric test, vHIT, cVEMP, oVEMP, SOT, and DHI. Patient and tumor characteristics were retrieved from the patient's history. Results: In the postoperative period, the reduction in gain of the lateral semicircular canal was observed in the vHITs of both patients. The DHI in case #1 increased after surgery, while it decreased in case #2. The improvement in postural performances compared to the preoperative SOT (CON 5, CON 6, composite score) and immediately after the procedure was observed. Conclusions: A specific diagnostic protocol is necessary to compare the results of different surgical techniques and approaches. Diagnostic tests performed before the surgery should be repeated within a specific time frame during postoperative follow-up to enable the comparison of results. The proposed protocol can help us better understand the processes ongoing during tumor growth and postoperative vestibular compensation.

Customized Vestibular Rehabilitation for Vestibular Schwannoma Excision via Translabyrinthine Approach: A Single-Center Experience

Objectives: To evaluate the effectiveness of intensive customized vestibular rehabilitation after vestibular schwannoma (VS) excision. Methods: 52 patients who underwent VS removal via a translabyrinthine approach from 2020 to 2022 were involved in this study. Bedside examination, video head impulse test (vHIT), functional head impulse test (fHIT), and the dizziness handicap inventory (DHI) were performed before and after the rehabilitation, which consisted of 10 sessions of specifically designed vestibular, visual, and physical integrated training. Results: After rehabilitation, the vHIT showed overall unchanged values on the affected and healthy side. In contrast, the scores of fHIT, which explores the higher connection of the vestibular system with visual and cerebellar pathways, improved on both the pathological and healthy sides after training (p-value 0.004 and 0.000, respectively). The effectiveness of the rehabilitation was reinforced by the DHI scores, which were considerably lower after training. Conclusions: To our knowledge, this is the first study to explore fHIT outcomes after removal of VS, estimating the impact of rehabilitation on the overall compensation process. The outcomes support the role of extensive postsurgical rehabilitation in the compensatory process, even just a few days after surgery.

Clinical practice guideline on the management of vestibular schwannoma

INTRODUCTION

Vestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy.

MATERIAL AND METHODS

This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC.

RESULTS

A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found.

CONCLUSIONS

This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.

Vestibular schwannoma with fluid-fluid levels mimicking aneurysm bone cyst

Of 6%-8%, cerebral tumors are intracranial schwannomas, also known as neurinomas, which frequently arise from the nerve sheath. Eighth cranial nerve (CN VIII), also known as the vestibulocochlear nerve, is the site of genesis of the majority of schwannomas, which account for 80%-90% of cerebellopontine angle tumors. In this paper, we intended to describe an uncommon cystic vestibular schwannoma with multiple fluid-fluid levels. Surgical excision was performed using the translabyrinthine approach. The report highlights schwannomas' adherence to and invasion of adjacent anatomical structures. We discuss a number of differential diagnoses, the pathophysiology of fluid-fluid levels, and the imaging features of cystic vestibular schwannomas.