Does Essential Tremor Alter the Axonal Excitability Properties of Lower Motor Neurons?

This study aimed to identify alterations in the excitability of distal motor axons in subjects with ET, with the intention of clarifying whether a trans-synaptic mechanism or LMN adaptation for tremor affects the LMNs of subjects with ET. Methods: Twenty-one consecutive patients diagnosed with ET underwent a clinical and electrophysiological evaluation. For the enrolled cases and 45 age- and gender-matched healthy controls, automated nerve excitability testing with threshold tracking techniques (QTRACS software with TRONDF multiple-excitability protocol) was used to evaluate multiple nerve excitability indices in distal median nerve motor axons. Results: The automated protocol calculated the strength–duration time constant, parameters of threshold electrotonus and current–threshold relationship, and the recovery cycle of excitability. Comparisons of the automated nerve excitability testing parameters revealed no significant differences between the ET and control groups in any of strength–duration time constant, threshold electrotonus, current–threshold relationship, and recovery cycle, whereas the rheobase was higher in the ET group (3.4 ± 1.1 vs. 2.3 ± 1.1, mean ± standard error mean; P
Source: Journal of Clinical Neurophysiology - Category: Neurology Tags: Original Research Source Type: research