Deep Brain Stimulation for Voice Tremor: Left, Right, or Both Hemispheres?

Overview

Deep Brain Stimulation (DBS) is the gold standard treatment for Essential Tremor (ET). ET is a movement disorder which causes the arms, feet, fingers, head or voice to involuntarily shake. The DBS surgical procedure involves implanting an electrode deep within the brain which blocks damaging signals that cause the tremor. Essential Voice Tremor (EVT) is the vocal manifestation of ET and a number of individuals have both ET and EVT, and when these patients are implanted for their ET, their EVT symptoms are often also mitigated. This study aims to quantify the effects of DBS on EVT by testing on these ET+EVT patients. In addition to this, we hope to determine which hemisphere of the brain is responsible for larynx control: left or right.

Essential Tremor (ET) is the most common movement disorder in adults, affecting approximately 5% of individuals over the age of 65. Of this 5%, roughly 20% of these patients suffer from Essential Voice Tremor (EVT): the phonatory manifestation of ET. Patients with EVT lose their ability to speak due to a tremor in the muscles of the larynx, pharynx, palate, and tongue. Because of this, an individual's quality of life is limited because they can no longer communicate effectively. The purpose of this study is to quantify to what degree Deep Brain Stimulation improves Essential Voice Tremor. In addition to this, we hope to examine which brain hemisphere is responsible for these positive results: right, left, or both, in a prospective, randomized, double-blinded manner. By finding out more about the subcortical control underpinning speech, we will be able to improve our treatments and understanding of EVT and other neurological speech disorders.