Although essential tremor (ET) is the most common movement disorder, little is known regarding its pathophysiology. Cutaneous silent period (CSP) is a spinal inhibitory reflex that causes suppression of the voluntary muscle contraction that is induced by strong electrical stimulation of the cutaneous nerves. Clinical interest in the CSP stems from its potential usefulness for evaluating segment and components of sensory nerves that are not well assessed by standard electrodiagnostic methods. The aim of this study was to investigate CSP in patients with ET before and after treatment. A total of 30 patients (12 females + 18 males), having ET diagnosis and propranolol treatment initiated, were studied with technique of CSP. Patient group's pre-treatment latency average is found 84.45 ± 18.63, average CSP duration 42.37 ± 11.82, and CSP final latency average 127.10 ± 19.13. According to post-treatment CSP analysis, it is seen that patients' average latency values are found 83.14 ± 20.92 and it is determined that there is no significant statistical difference compared to pre-treatment latency values (p > 0.05). Post-treatment average CSP duration is found 36.64 ± 13.38, and it is seen that there is a significant statistical shortening compared to pre-treatment durations (p < 0.05). Patients' post-treatment CSP final latency averages are found 123.17 ± 13.67, and it is determined that there is no significant statistical difference compared to pre-treatment latency values (p > 0.05). The main finding of this study is that in ET the CSP is prolonged and that treatment with propranolol shortens the CSP and brings it closer to normal values. A small dose of propranolol has the effect of shortening pathologically prolonged CSP in a subset of ET patients (women and without family history), making further investigations with this method interesting. From this point of view in our study, patients with ET treatment give an idea of the effectiveness of propranolol. In recent years, a technique of CSP is interested in the field of electrophysiology and shows the effect of ET that given other pharmacological treatment and also it can be considered a quantitative measure to compare them. The usefulness of CSP should be supported by further studies with more patients.
Keywords: Cutaneous silent period; Essential tremor; Propranolol.