This Japanese study included 197 patients with P-BPPV treated over a two and a half year period. The vast majority had idiopathic BPPV (n=157). The remaining 40 had secondary BPPV, eight following head trauma, 14 due to prolonged bed rest and 18 related to inner ear disease, including sudden sensorineural deafness, Ménière’s disease and vestibular neuritis. A single Epley manoeuvre was performed by the same therapist in all patients, and patients were followed up weekly with repeat Epley manoeuvre to assess response. Comparing response at seven days, there was 73% resolution in the idiopathic group, 56% in the inner ear group (no significant difference), 25% in the head trauma group and 36% in the bed rest group (both statistically significant). The study then assessed resolution over the longer term with helpful Kaplan Meier curves to demonstrate that again there was no significant difference in resolution rates between the idiopathic and inner ear groups at one and three months post Epley manoeuvre, but significantly lower rates of resolution at these intervals in the head trauma and bed rest groups. In all groups the majority of patients had resolution by three months. This was poorest in the head trauma group with 25% of patients still unresolved, whereas for the three other groups this was less than 10%. One must bear in mind the small numbers of patients in each of the secondary BPPV groups when considering the strength of the conclusions, however this study certainly adds weight to the notion that idiopathic P-BPPV has a better outcome than that secondary to a separate pathology. The authors hypothesise regarding the possible mechanism of deposition of otoconial debris to explain their observations.