title: Clinical decision-making in functional and hyperkinetic movement disorders.
abstract: OBJECTIVE
  Functional or psychogenic movement disorders (FMD) present a diagnostic challenge. To diagnose FMD, clinicians must have experience with signs typical of FMD and distinguishing features from other hyperkinetic disorders. The aim of this study was to clarify the decision-making process of expert clinicians while diagnosing FMD, myoclonus, and tics.
  
  
  METHODS
  Thirty-nine movement disorders experts rated 60 patients using a standardized web-based survey resembling clinical practice. It provided 5 steps of incremental information: (1) visual first impression of the patient, (2) medical history, (3) neurologic examination on video, (4) the Bereitschaftspotential (BP), and (5) psychiatric evaluation. After full evaluation of each case, experts were asked which diagnostic step was decisive. In addition, interim switches in diagnosis after each informational step were calculated.
  
  
  RESULTS
  After full evaluation, the experts annotated the first impression of the patients as decisive in 18.5% of cases. Medical history was considered decisive in 33.3% of cases. Neurologic examination was considered decisive in 39.7%, the BP in 8%, and the psychiatric interview in 0.5% of cases. Most diagnostic switches occurred after addition of the medical history (34.5%). Addition of the neurologic examination led to 13.8% of diagnostic switches. The BP results led to diagnostic switches in 7.2% of cases. Psychiatric evaluation resulted in the lowest number of diagnostic switches (2.7% of cases).
  
  
  CONCLUSIONS
  Experts predominantly rely on clinical assessment to diagnose FMD. Importantly, ancillary tests do not determine the final diagnosis of this expert panel. In general, the experts infrequently changed their differential diagnosis.
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Sandra M A
authors.initials: SM
authors.lastname: van der Salm
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Anne-Fleur
authors.initials: AF
authors.lastname: van Rootselaar
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Daniëlle C
authors.initials: DC
authors.lastname: Cath
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: de Haan
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands.
authors.forename: Johannes H T M
authors.initials: JH
authors.lastname: Koelman
authors.affiliation: From the Department of Neurology and Clinical Neurophysiology (S.M.A.v.d.S., A.-F.v.R., J.H.T.M.K.) and Clinical Research Unit (R.J.d.H.), Academic Medical Center, Amsterdam; Altrecht Academic Anxiety Center and Department of Clinical & Health Psychology (D.C.C.), University of Utrecht; and Department of Neurology (M.A.J.T.), University Medical Center Groningen, University of Groningen, the Netherlands. m.a.j.de.koning-tijssen@umcg.nl.
authors.forename: Marina A J
authors.initials: MA
authors.lastname: Tijssen
mesh_terms: D000066491:Clinical Decision-Making / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006948:Hyperkinesis / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D008297:Male; D009460:Neurologic Examination; D018709:Statistics, Nonparametric