Diagnostic agreement in patients with psychogenic movement disorders

Background: The reliability and applicability of published diagnostic criteria for psychogenic movement disorders (PMDs) have never been examined. Methods: Eight movement disorder and six general neurologists rated 14 patients diagnosed with PMD and 14 patients diagnosed with organic movement disorders. Raters provided a dichotomous judgment (i. e., psychogenic or organic) upon review of video-based movement phenomenology and a category of diagnostic certainty based on the Fahn-Williams and ShillGerber criteria after accessing standardized clinical information. We measured interobserver agreement on the diagnosis and clinical certainty judgment of PMD. Results: In both groups of raters, agreements were `` fair'' on the video-based dichotomous judgment, but improved to `` substantial'' after access to standardized clinical information. `` Slight'' to `` poor'' agreement was reached for the `` probable'' and `` possible'' categories of diagnostic certainty corresponding to both diagnostic criteria. Conclusions: Diagnosis according to clinical available criteria for PMD yields poor diagnostic agreement