The purpose of this study is to evaluate the vestibular effects of gamma-knife radiosurgery, as part of the treatment of vestibular schwannoma.

Vestibular schwannoma is a benign tumor located on the vestibulocochlear nerve. It represents 6 to 8% of intracranial tumors, 80% of ponto-cerebral angle tumors and its frequency is 13 cases per million inhabitants per year.

The main symptoms related to the development of vestibular schwannoma are unilateral deafness of perception, unilateral tinnitus, unilateral vestibular deficit vertigo, facial paralysis.

Management is divided into 3 options: monitoring, surgery and gamma-knife radiosurgery.

This study will focus on gamma-knife radiosurgery. The objective of this treatment is to stabilize the evolution of schwannoma.

This study aims to describe the vestibular effects of radiosurgery.

Inclusion Criteria :

• Men and women aged 18 to 90 included
• Subject who benefited from gamma-knife radiosurgery as part of the treatment of vestibular schwannoma
• Non-opposition of the subject to participate in the study
• Affiliation to a French social security scheme or beneficiary of such a scheme

Exclusion Criteria :

• Subject with another vestibular pathology
• Subject who did not benefit from a vestibular assessment before treatment with gamma-knife radiosurgery
• Legal incapacity or limited legal capacity
• Subject unlikely to cooperate in the study and/or weak cooperation anticipated by the investigator
• Subject without health insurance
• Subject being in the period of exclusion from another study or provided for by the "national volunteer file".