title: Functional tremor.
abstract: Functional tremor is the commonest reported functional movement disorder. A confident clinical diagnosis of functional tremor is often possible based on the following "positive" criteria: a sudden tremor onset, unusual disease course, often with fluctuations or remissions, distractibility of the tremor if attention is removed from the affected body part, tremor entrainment, tremor variability, and a coactivation sign. Many patients show excessive exhaustion during examination. Other somatizations may be revealed in the medical history and patients may show additional functional neurologic symptoms and signs. In cases where the clinical diagnosis remains challenging, providing a "laboratory-supported" level of certainty aids an early positive diagnosis. In rare cases, in which the distinction from Parkinson's disease is difficult, dopamine transporter single-photon emission computed tomography (DAT-SPECT) can be indicated.
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Schwingenschuh
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany. Electronic address: g.deuschl@neurologie.uni-kiel.de.
authors.forename: G
authors.initials: G
authors.lastname: Deuschl
mesh_terms: D006801:Humans; D011602:Psychophysiologic Disorders; D014202:Tremor
keywords: attention; distractibility; electrophysiologic tests; functional tremor; laboratory-supported criteria; positive diagnosis; positive signs; psychogenic; psychogenic tremor