The eye of the beholder: inter-rater agreement among experts on psychogenic jerky movement disorders
- Sandra M A van der Salm1,
- Rob J de Haan2,
- Daniëlle C Cath3,
- Anne-Fleur van Rootselaar1,
- Marina A J Tijssen1,4
- 1Department of Neurology and Clinical Neurophysiology, Academic Medical Centre, Amsterdam, The Netherlands
- 2Clinical Research Unit, Academic Medical Centre, Amsterdam, The Netherlands
- 3Altrecht Academic Anxiety Centre and Department of Clinical and Health Psychology, University of Utrecht, Utrecht, The Netherlands
- 4Department of Neurology, UMCG, University of Groningen, The Netherlands
- Correspondence to Dr M A J Tijssen, Department of Neurology AB 51, University Medical Centre Groningen (UMCG), PO Box 30.001, Groningen 9700 RB, The Netherlands;
- Received 7 September 2012
- Revised 18 January 2013
- Accepted 22 January 2013
- Published Online First 14 February 2013
Objective The current criteria for conversion disorder in the Diagnostic and Statistical Manual of Mental Disorders rely on the assumption that neurological disorders can be distinguished from conversion disorders through clinical assessment. This study aims to assess inter-rater agreement among clinicians with experience in the diagnosis of various hyperkinetic jerky movements, including psychogenic jerks.
Methods 60 patients with psychogenic jerks, myoclonus or tics were rated by international experts using a standardised survey resembling daily clinical practice. The survey included the following diagnostic steps: a short video offering a visual impression of the patients and their jerky movements, medical history, neurological examination (on video), additional investigations and the findings of a standardised psychiatric interview. The diagnosis and diagnostic certainty were scored after each step.
Results After all clinical information was given, moderate inter-rater agreement was reached (κ=0.56±0.1) with absolute agreement (100%) of experts on the diagnosis in 12 (20%) patients and reasonable agreement (>75%) in 43 (72%) patients. Psychiatric evaluation did not contribute to inter-rater agreement or diagnostic certainty.
Conclusions Our findings illustrate the fact that experienced movement disorder specialists moderately agree on the clinical diagnosis of jerky movements. Clinical assessment, especially by a team of clinicians in challenging individual cases, might improve diagnostic agreement.