Are there diurnal variations in the results of the Dix-Hallpike manoeuvre?

This study examines diurnal variation in the result of the Dix-Hallpike manoeuvre when testing for benign paroxysmal positional vertigo in a randomised crossover study of the order of diagnostic testing in a community out-reach clinic for a tertiary neurological centre in Wellington, New Zealand. Study participants were adults referred for physiotherapy treatment. Dix-Hallpike manoeuvres were performed to both ears, and groups were randomly allocated to have a morning, then afternoon, sequence of testing or vice versa. The results of the Dix-Hallpike manoeuvres were digitally recorded and reviewed by a second blinded assessor. A total of 27 of 50 participants (54%) tested positive on at least one of the days, six of 27 (22%) had discordant results. The difference in marginal proportions was 0% (95% confidence interval: -9.6 to 9.6), p=1.0. The time of day is not a factor in false negative Dix-Hallpike manoeuvres, although 22% of those with positive results tested negative on one of the two measurements.