Vestibular Rehabilitation: Improving Symptomatic and Functional Outcomes of Persons With Vestibular Schwannoma: A Systematic Review.

Every outcome was rated very low certainty. The authors state that including non-randomised and observational studies alongside randomised trials meant the certainty could never have been rated high or moderate. Five of the nine randomised trials were at high risk of bias, the most common reason being that the way people were allocated to groups was poorly described or incomplete, and only one trial was rated low risk. Four of the five two-group non-randomised trials were at serious risk of bias. In three of them the gentamicin decision was based on hearing and tumour size, so those groups may have differed at the start in ways that affect the result. All five single-group before-and-after studies were rated poor quality, often because dropouts and sample size calculations were not reported. Some studies contained very few people with vestibular schwannoma. The tai chi study had 2 participants with a vestibular schwannoma, and one habituation trial had 2 people with vestibular schwannoma in one arm only, so several positive findings rest on a handful of patients. Eight of the 21 surgical studies did not report which surgical approach was used, and different approaches may produce different postoperative problems, so the populations may not be comparable. Most of the evidence concerns rehabilitation started soon after surgery, so little is known about rehabilitation during surveillance or after radiotherapy. No included study reported depression, anxiety or disease-specific quality of life, which were outcomes the review set out to examine. The authors suggest this may be because specific questionnaire names were not used in the search strategy.

The text supplied here contains no funding statement and no conflict-of-interest declaration, so it is not possible to say from this material who paid for the review or what the authors declared.

Do not read this as proof that vestibular rehabilitation works after treatment for a vestibular schwannoma. Every outcome was graded very low certainty, most included studies were at high risk of bias, and several of the positive results come from uncontrolled before-and-after studies, so the improvements may not be due to the exercises. Do not treat the gentamicin prehabilitation result as established either: it comes from two non-randomised studies where hearing and tumour size decided who received gentamicin.