Essential Tremors: A Detailed Review

Abstract

Essential tremor (ET) is the most prevalent movement disorder globally and is ten times more prevalent than Parkinson's. It is considered one of the most common movement disorders with various treatment options reported in clinical practice but uncertainty about the most robust one. The International Parkinson and Movement Disorder Society recently reviewed the clinical studies of essential tremors and updated the treatment guidelines. Mild to moderate tremor severity can sometimes be managed with occupational treatment such as speech therapy or adaptation. In contrast, the first-line pharmacological treatments include symptomatic treatment with propranolol, primidone, and topiramate. Botulinum toxin is preferred for selected cases, whereas invasive treatments should be considered a severe essential tremor treatment option. Focused ultrasound thalamotomy is attracting a lot of attention as a new therapy for essential tremors. Misdiagnosis among tremor syndromes is another point of concern and impacts both clinical care and research. A new neurophysiological measure, known as the tremor stability index, is introduced recently to attain diagnostic accuracy between Parkinson's disease tremor and essential tremor. Also, ET-Plus is a newly suggested term for the classification of tremor in the recent Consensus statement, which acknowledges the presence of additional neurological signs in patients with ET. This review includes in detail defining ET, hypothesis about ET, clinical features along with points to consider while differentiating between ET and Parkinson's Disease (PD), evaluation of ET based on laboratory findings, treatment procedures, measures to reduce misdiagnosis between ET and PD, and reality about the new term ET-Plus syndrome.