Persistent postural-perceptual dizziness (PPPD) is a chronic condition affecting balance which is manifested through unsteadiness or dizziness, provoked by changes in position or visual stimulation. These symptoms must be present at least for three months, most of the days of the week. The underlying aetiology of this disorder is still not clear, although it is thought that temporary changes in balance function caused by a specific event may become chronic, even if the initial event is resolved, so that it PPPD may be the result of a maladaptive response. As the problem persists it may significantly impact daily activities and quality of life. As the pathophysiology of this disorder is not clearly understood it is difficult to address therapies on any specific target mechanism. However, drug and non-drug interventions are currently being used in people with chronic vestibular symptoms and could be possible therapeutic options in people with PPPD. Non-pharmacological therapies addressing associated psychological symptoms like anxiety and mood disturbance are counselling, cognitive behavioural therapy, meditation and mindfulness. Vestibular rehabilitation could be employed through an individualized exercise program based on balance, visual and postural exercises. These exercises aim to reduce abnormal balance signals, causing habituation. This review investigated whether non-drug interventions may be helpful and safe to improve symptoms of PPPD compared to no treatment or placebo.
This review is important for
People with PPPD their loved ones/caregivers, health professionals caring for this population, general practitioners, researchers, and policymakers. As balance disorders are difficult to diagnose and treat PPPD was ranked as one of the highest priorities. To date there are no treatment recommendations for treatment strategies, thus reviewing the evidence is important.
Outcomes of this review
This is a new Cochrane Systematic Review (CSR) published in 2023. The outcomes analysed were an improvement or change in vestibular symptoms, serious or other adverse events; disease-specific or generic health-related quality of life. The authors considered three-time points for outcome assessment and reporting: 3 to 6 months, 6 to 12 months and more than 12 months. No studies were identified that met the original inclusion criteria but, this CSR included only 1 trial published and/or registered up to November 2022 which compared the use of transcranial direct current stimulation to sham treatment in 24 adult participants. Results showed that it is uncertain whether nonpharmacological interventions (transcranial direct current stimulation) improve disease-specific health-related quality and adverse events. The included study did not look at other outcomes. These results must be interpreted with caution since (i) only one very small study with few participants was suitable for inclusion and its intervention was not conventional for PPPD (transcranial direct current stimulation), making wide confidence intervals, and leading to imprecision in the overall effect estimates (ii) This study only analysed few of the outcomes of this review so that the efficacy of this intervention for vestibular symptoms and generic quality of life is unknown. (iii) Data on adverse events was poor due to the small number of participants. (iv) Furthermore, follow-up was only conducted at three months, so long-term effects are unknown. (v) There is the possible confounding of selective serotonin reuptake inhibitor (SSRI) therapy which was administered at enrolment to both arms of this study. (vi) As this review included only participants who had received a diagnosis of PPPD recently defined criteria society criteria studies which were conducted before may have been omitted.
Author’s conclusion of the review
There is extremely limited evidence and therefore it is highly uncertainty whether non-pharmacologic interventions compared to placebo improve symptoms in PPPD or whether they cause any adverse events. Many of the studies had not established appropriate control arms, and as the conditions are supposed to be chronic the assessment of the outcomes should be made in the long term to assess whether they are associated with any potential harms. Healthcare practitioners in this area should be aware of this uncertainty when choosing treatment options for this condition.
Future recommendations
The authors recommended that large-scale, multi-centre placebo-controlled studies are needed, (a) to identify appropriate interventions and to increase the evidence of whether any interventions may benefit people with PPPD or whether they are associated with any harm. (b) The authors suggest that future studies should identify participants through agreed diagnostic criteria for PPD. (c) Given the chronicity of the condition, appropriate follow-up periods should be identified, for which the authors suggest a period of at least six months of follow-up. (d) Furthermore, a collaboration between people with PPPD, healthcare professionals and researchers, would be advisable as it may bring forth a core outcome set, how to measure them and the clinically significant effect size.
by Robin Kuruvila Sentinella