Author Response to Letter to the Editor

Dear Editor:

We deeply appreciate the comments provided by López-Blanco et al. regarding our recent publication entitled “Tremor Control Devices for Essential Tremor: A Systematic Literature Review.”¹

We basically agree with the aspects highlighted by these authors; however, we would like to discuss them briefly.

First, the main objective of our systematic literature review was to conduct a literature search about tremor-control devices using standardized criteria regarding efficacy and comfort in patients diagnosed with essential tremor (ET). We did not include computer software/hardware to control kinetic tremor by using the mouse of a PC, because the scientific literature supporting this technology have included patients with multiple sclerosis exclusively.^2,3 We also excluded websites that did not include peer-review literature supporting effectiveness.³

Second, we fully agree with their second statement regarding the lack of publications of negative studies, and independent testing outside the initial developers.³ It would be interesting to study whether publication bias is more prevalent among nonpharmacologic interventions as compared to drugs in tremor and other neurological related fields.⁴

Third, we also agree on the importance of duration of clinical trials aimed to analyze the inherent variability of tremor intensity during testing. In order to study the effectiveness of tremor-suppression devices in ET, the functional impairment should ideally be studied at home, or at least, in a friendly environment, either in a natural/casual setting or under carefully-controlled circumstances in the lab, for a certain amount of time, to reduce tremor fluctuations due to confusing factors (pharmacological treatment effects, anxiety, etc.).

We appreciate the above comments provided by López-Blanco et al. which definitively improve the discussion of our article and highlight the importance of well-designed pharmacological and nonpharmacological clinical trials in ET.