Psychogenic tremor: long-term prognosis in patients with electrophysiologically confirmed disease.

We describe the presenting features and long-term outcomes of patients with electrophysiologically-confirmed psychogenic tremor. Clinical information for all patients with psychogenic tremor confirmed by our Movement Disorders Neurophysiology Laboratory (2003-2004) was reviewed. A follow-up questionnaire was administered to all included patients in 2007. Psychogenic tremor was documented in 62 patients; 33 responded to the questionnaire (53%). Median onset-age was 50 years (range, 15-71); 23 were female (70%). Clinical certainty of psychogenic etiology was: definite, 8 (24%); probable, 16 (49%), and possible, 9 (27%). Characteristic electrodiagnostic features of psychogenic tremor were documented in all. All but two patients were ultimately given a definite diagnosis of psychogenic tremor; recommended psychiatric consultation was only done by 12 (36%). Twenty-one patients (64%) rated tremor disability as moderate or severe after a median follow-up of 5.1 years (range, 3.3-19). Improvement occurred spontaneously in 5 (15%), and after a specific intervention in 4 (12%), whereas 3 (9%) had mild but unchanged symptoms. The mean duration of symptoms, prior to diagnosis with psychogenic tremor, was significantly shorter for patients with mild or no tremor at follow-up (P = 0.037). Physiologically-confirmed psychogenic tremor carries a poor prognosis, with unremitting or worse tremor persisting 3-years after diagnosis in most.