The response of the central and peripheral tremor component to octanoic acid in patients with essential tremor

Objective: To investigate the effect of octanoic acid (OA) on the peripheral component of tremor, as well as OA's differential effects on the central and peripheral tremor component in essential tremor (ET) patients. Methods: We analyzed postural tremor accelerometry data from a double-blind placebo-controlled crossover study evaluating the effect of 4 mg/kg OA in ET. The weighted condition was used to identify tremor power for both the central and peripheral tremor components. Exploratory non-parametric statistical analyses were used to describe the relation between the central and peripheral component of tremor power. Results: A peripheral tremor component was identified in 4 out of 18 subjects. Tremor power was reduced after OA administration in both the central and the peripheral tremor component. There was a positive correlation of tremor power between the central and peripheral component, both after placebo and OA. Conclusions: When present, the peripheral component was closely related to the central tremor component. We hypothesize that the magnitude of the peripheral mechanical component of tremor is determined by that of the central component. Significance: Both central and peripheral component of tremor are reduced after OA, with the central component providing the energy driving the peripheral component. (C) 2018 Published by Elsevier B.V. on behalf of International Federation of Clinical Neurophysiology.