Tremor: Natural Behaviour, Trial Design and Physiological Outcome Measures

For the purposes of neurological practice tremor is defined as an involuntary rhythmical, oscillatory movement of a body part [1]. Pathological tremors are involuntary with the possible exception of “psychogenic” tremor, in which the pathophysiological mechanisms are poorly understood [1,2]. Healthy people also have an involuntary low-amplitude physiological tremor and can voluntarily mimic largemagnitude tremors [1,3].