Pharmacological interventions for persistent postural-perceptual dizziness (PPPD)

Background Persistent postural-perceptual dizziness (PPPD) is a chronic balance disorder, which is characterised by subjective unsteadiness or dizziness that is worse on standing and with visual stimulation. The condition was only recently defined and therefore the prevalence is currently unknown. However, it is likely to include a considerable number of people with chronic balance problems. The symptoms can be debilitating and have a profound impact on quality of life. At present, little is known about the optimal way to treat this condition. A variety of medications may be used, as well as other treatments, such as vestibular rehabilitation. Objectives To evaluate the benefits and harms of pharmacological interventions for persistent postural-perceptual dizziness (PPPD). Search methods The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (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Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials.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 21 November 2022. Selection criteria We included randomised controlled trials (RCTs) and quasi-RCTs in adults with PPPD, which compared selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs) with either placebo or no treatment. We excluded studies that did not use the Barany Society criteria to diagnose PPPD and studies that followed up participants for less than three months. Data collection and analysis We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vestibular symptoms (assessed as a dichotomous outcome - improved or not improved), 2) change in vestibular symptoms (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) generic health-related quality of life and 6) other adverse effects. We considered outcomes reported at three time points: 3 to < 6 months, 6 to <= 12 months and > 12 months. We planned to use GRADE to assess the certainty of evidence for each outcome. Main results We identified no studies that met our inclusion criteria. Authors' conclusions At present, there is no evidence from placebo-controlled randomised trials regarding pharmacological treatments - specifically SSRIs and SNRIs - for PPPD. Consequently, there is great uncertainty over the use of these treatments for this condition. Further work is needed to establish whether any treatments are effective at improving the symptoms of PPPD, and whether their use is associated with any adverse effects.