Slow orthostatic tremor and the case for routine electrophysiological evaluation of all tremors

Tremor rating scales and laboratory tools for assessing tremor

“…Most pathologic tremors have a frequency of 4-12 Hz. Exceptions are myorhythmia (frequency < 4 Hz) [7], orthostatic tremor (frequency = 13-18 Hz) [8], and cortical tremor (frequency 7-18 Hz) [9].…”

“…Two oscillations must have a consistent phase relationship at a particular frequency to have high coherence, which ranges from 0 to 1. Coherence analysis is very helpful in the diagnosis of functional (psychogenic) tremor [110] and primary orthostatic tremor [8]. In psychogenic (functional) tremor, coherence is useful in demonstrating the characteristic frequency entrainment of tremor by rhythmic voluntary movement in another body part [110][111][112].…”