Positive pressure therapy for Ménière's disease

BACKGROUND: Ménière's disease is a condition that causes recurrent episodes of vertigo, associated with hearing loss and tinnitus. It is often treated with medication, but different interventions are sometimes used. Positive pressure therapy is a treatment that creates small pressure pulses, generated by a pump that is attached to tubing placed in the ear canal. It is typically used for a few minutes, several times per day. The underlying cause of Ménière's disease is unknown, as is the way in which this treatment may work. The efficacy of this intervention at preventing vertigo attacks, and their associated symptoms, is currently unclear. OBJECTIVES: To evaluate the benefits and harms of positive pressure therapy versus placebo or no treatment in people with Ménière's disease. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; CENTRAL; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 14 September 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs in adults with a diagnosis of Ménière's disease comparing positive pressure therapy with either placebo or no treatment. We excluded studies with follow-up of less than three months.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vertigo (assessed as a dichotomous outcome - improved or not improved), 2) change in vertigo (assessed as a continuous outcome, with a score on a numerical scale) and 3) serious adverse events. Our secondary outcomes were: 4) disease-specific health-related quality of life, 5) change in hearing, 6) change in tinnitus and 7) other adverse effects. We considered outcomes reported at three time points: 3 to < 6 months, 6 to ≤ 12 months and > 12 months. We used GRADE to assess the certainty of evidence for each outcome.  MAIN RESULTS: We included three studies with a total of 238 participants, all of which compared positive pressure using the Meniett device to sham treatment. The duration of follow-up was a maximum of four months.  Improvement in vertigo A single study assessed whether participants had an improvement in the frequency of their vertigo whilst using positive pressure therapy, therefore we are unable to draw meaningful conclusions from the results.  Change in vertigo Only one study reported on the change in vertigo symptoms using a global score (at 3 to < 6 months), so we are again unable to draw meaningful conclusions from the numerical results. All three studies reported on the change in the frequency of vertigo. The summary effect showed that people receiving positive pressure therapy had, on average, 0.84 fewer days per month affected by vertigo (95% confidence interval from 2.12 days fewer to 0.45 days more; 3 studies; 202 participants). However, the evidence on the change in vertigo frequency was of very low certainty, therefore there is great uncertainty in this estimate.   Serious adverse events None of the included studies provided information on the number of people who experienced serious adverse events. It is unclear whether this is because no adverse events occurred, or whether they were not assessed and reported.  AUTHORS' CONCLUSIONS: The evidence for positive pressure therapy for Ménière's disease is very uncertain. There are few RCTs that compare this intervention to placebo or no treatment, and the evidence that is currently available from these studies is of low or very low certainty. This means that we have very low confidence that the effects reported are accurate estimates of the true effect of these interventions. Consensus on the appropriate outcomes to measure in studies of Ménière's disease is needed (i.e. a core outcome set) in order to guide future studies in this area and enable meta-analyses of the results. This must include appropriate consideration of the potential harms of treatment, as well as the benefits.