Abstract: The review includes 11 trials involving 855 participants. A total of nine studies used post-Epley postural restrictions as their modification of the Epley manoeuvre. There was no evidence of a difference in the results for post-treatment vertigo intensity or subjective assessment of improvement in individual or pooled data. All nine trials included the conversion of a positive to a negative Dix-Hallpike test as an outcome measure. Pooled data identified a significant difference from the addition of postural restrictions in the frequency of Dix-Hallpike conversion when compared to the Epley manoeuvre alone. In the experimental group 88.7% (220 out of 248) patients versus 78.2% (219 out of 280) in the control group converted from a positive to negative Dix-Hallpike test (risk ratio (RR) 1.13, 95% confidence interval (CI) 1.05 to 1.22, P = 0.002). No serious adverse effects were reported, however three studies reported minor complications such as neck stiffness, horizontal BPPV, dizziness and disequilibrium in some patients. There was no evidence of benefit of mastoid oscillation applied during the Epley manoeuvre, or of additional steps in the Epley manoeuvre. No adverse effects were reported. There is evidence supporting a statistically significant effect of post-Epley postural restrictions in comparison to the Epley manoeuvre alone. However, it important to note that this statistically significant effect only highlights a small improvement in treatment efficacy. An Epley manoeuvre alone is effective in just under 80% of patients with typical BPPV. The additional intervention of postural restrictions has a number needed to treat (NNT) of 10. The addition of postural restrictions does not expose the majority of patients to risk of harm, does not pose a major inconvenience, and can be routinely discussed and advised. Specific patients who experience discomfort due to wearing a cervical collar and inconvenience in sleeping upright may be treated with the Epley manoeuvre alone and still expect to be cured in most instances. There is insufficient evidence to support the routine application of mastoid oscillation during the Epley manoeuvre, or additional steps in an 'augmented' Epley manoeuvre. Neither treatment is associated with adverse outcomes. Further studies should employ a rigorous randomisation technique, blinded outcome assessment, a post-treatment Dix-Hallpike test as an outcome measure and longer-term follow-up of patients.

Plain-language summary: We included 11 studies in this review, with a total of 855 participants. Nine studies looked at post-treatment postural restrictions (using a neck brace/head movement restrictions/instructions to sleep upright) following the Epley manoeuvre. There was a statistically significant difference found when these restrictions were compared to a control treatment of the Epley manoeuvre alone. Although there was a difference between the groups, adding postural restrictions conferred only a small additional benefit since the Epley manoeuvre was effective alone in just under 80% of patients. Four of the studies reported minor complications such as neck stiffness, horizontal BPPV (a subtype of BPPV which is similar to posterior canal BPPV, but has some distinct differences in terms of the signs and symptoms), dizziness and disequilibrium (the feeling of unsteadiness on ones feet) in some patients. Additionally, two studies looked into the application of oscillation/vibration to the mastoid region during the Epley manoeuvre compared to control; the intervention produced no difference in outcome between these groups. One study that also researched post-treatment postural restrictions looked into extra steps in the Epley manoeuvre. Compared to the control treatment there were no significant differences in outcomes. No serious adverse effects were reported in any of the studies in the review. The results should be interpreted carefully and further trials are needed.