Why is Essential Tremor so Difficult to Treat? A Literature Review

Abstract

Essential tremor (ET) is the most common movement disorder and affects tens of millions of individuals worldwide. It is characterized by isolated upper-limb tremors for at least three years without other neurological signs or tremors in other locations. Despite ET being a widespread movement disorder, its etiology and pathophysiology are poorly understood. This lack of understanding poses significant challenges towards the development of treatments and cures. There is no cure for ET, and current treatments for ET are limited and are often insufficient. ET symptoms can differ greatly between patients, and phenotyping is the only method for diagnosis. ET often overlaps with other disorders including dystonia and Parkinson’s disease, which further complicates diagnosis and treatment. Current treatments begin with pharmacotherapy, and progress to surgical options in drug-resistant patients. There is ongoing research into non-invasive electrical stimulation treatments that may prove to be safe and effective; however, further research is needed. The aim of this review is to assess the literature and summarize why ET is so difficult to treat. We evaluate the efficacy of current treatments, and the potential of future treatments. We summarize four reasons why ET remains so difficult to treat: 1) the unknown etiology and pathophysiology, 2) the lack of a suitable animal model, 3) difficulties with diagnosis, and 4) absence of personalized treatments. Despite the current challenges, ET remains an active area of research and novel experimental treatments may produce safe and effective non-invasive therapeutic options for ET.