Psychogenic parkinsonism: clinical spectrum and diagnosis

Patients with psychogenic parkinsonism (PP), like those with Parkinson's disease (PD), may have tremor, bradykinesia, rigidity, and gait disturbances. Unusual features predominate in PP, but clear psychogenic signs may not be obvious. Because PP may be difficult to diagnose, identifying a wider spectrum of disease manifestations that point toward psychogenic rather than organic parkinsonism could be useful for clinicians.

We retrospectively reviewed the charts and clinical data for all patients referred for parkinsonism to a single physician at our movement disorders clinic from 1980 to 2012.

Patients with PP represented 1.5% of all patients referred for parkinsonism. Among 36 patients with PP, the most common complaints were tremor (31), gait disturbance (18), fatigue (12), and diminished balance (10). Neurologic examination revealed 12 patients with unusual (functional) postures, 5 with a normal exam, and none with micrographia, hypophonia, or hypomimia. Seven of 36 patients improved, 6 of these with antidepressant therapy.

PP is not rare in a movement disorders practice. Leg tremor is more likely in PP than in PD, whereas falls are rare. Unusual (nonphysiologic) postures may be present. The outcome generally is not favorable, although antidepressants are beneficial in some patients with disease duration of <2 years. The presence of micrographia, hypophonia, or hypomimia strongly suggests an organic cause of parkinsonism rather than PP.