Diagnosing functional tremors is challenging, usually relying solely on history and examination. However, it has been suggested that clinicians may disregard the outcome of observational tests; basing diagnoses on history alone. The entrainment test is described as a useful clinical test for distinguishing between functional and organic tremors but the literature suggests variability in the way that it is performed and interpreted. This study aimed to investigate the extent of the variability in the way that clinicians perform and interpret the entrainment test when assessing tremors, as well as the influence of history on clinicians' assessment of the test.Method
31 clinicians, recruited from specialist movement disorder centres and conferences, answered a novel questionnaire assessing performance and interpretation of the entrainment test. Clinicians watched videos of patients with organic and functional tremors performing the test. After each video clinicians decided whether the test was positive or negative. They were then read a fictional history and given the opportunity to change their assessment.Results
4 out of 62 initial assessments changed, independent of the history that the clinician heard (ï£2=1.974, p=0.542). The mean questionnaire score was 6.7 out of 12 (standard deviation 2.3). Those reporting confidence in their knowledge of the entrainment test scored significantly higher, indicating greater knowledge, than those reporting limited confidence (mean=7.8, standard deviation 1.9, 95% confidence interval, 7.0-8.7 vs. mean=5.2, standard deviation 2.1, 95% confidence interval, 4.1-6.4. t=3.658, p=0.001). 5 clinicians did not include a definition of “pure entrainment” when asked for signs signifying a positive test.Conclusion
History does not exert undue influence over assessment of the entrainment test, except in a minority of cases. Training and published guidelines are needed to standardise entrainment test methodology.