Tremor retrainment as therapeutic strategy in psychogenic (functional) tremor

Entrainment, the change or elimination of tremor as patients perform a voluntary rhythmical movement by the unaffected limb, is a key diagnostic hallmark of psychogenic tremor.

To evaluate the feasibility of using entrainment as a bedside therapeutic strategy ('retrainment') in patients with psychogenic tremor.

Ten patients with psychogenic tremor (5 women, mean age, 53.6 ± 12.8 years; mean disease duration 4.3 ± 2.7 years) were asked to participate in a pilot proof-of-concept study aimed at "retraining" their tremor frequency. Retrainment was facilitated by tactile and auditory external cueing and real-time visual feedback on a computer screen. The primary outcome measure was the Tremor subscale of the Rating Scale for Psychogenic Movement Disorders.

Tremor improved from 22.2 ± 13.39 to 4.3 ± 5.51 (p = 0.0019) at the end of retrainment. The benefits were maintained for at least 1 week and up to 6 months in 6 patients, with relapses occurring in 4 patients between 2 weeks and 6 months. Three subjects achieved tremor freedom.

Tremor retrainment may be an effective short-term treatment strategy in psychogenic tremor. Although blinded evaluations are not feasible, future studies should examine the long-term benefits of tremor retrainment as adjunctive to psychotherapy or specialized physical therapy.