Double-Blind, Placebo Controlled Pilot Study of Octanoic Acid in Essential Tremor

Background: * Essential tremor (ET) is a neurological disorder characterized by uncontrollable shaking. Several medications are used to treat ET; however, they are often only partly effective and can have side effects. * Research studies have shown that octanol, a food additive similar to alcohol, can improve tremor in animals. Octanol is less likely to make people drunk than alcohol. Two earlier NIH studies found that one form of octanol, called 1-octanol, did improve tremor in some people and had few side effects. * In the body, 1-octanol is converted to octanoic acid. Researchers are interested in finding out whether octanoic acid can help people with ET. Objectives: * To find out if octanoic acid can improve hand tremor in people with essential tremor. * To measure levels of octanoic acid in the blood after it is taken. Eligibility: * Patients 21 years of age and older with ET, who are willing to abstain from alcohol, caffeine, and all medications as required by the study and who are willing and able to fast for up to 12 hours at a time. * Participants may not be of Asian or Native American ancestry because of genetic susceptibilities to the intoxicating effects of the study drug. Design: * This study requires a 3-day hospital admission as well as two outpatient visits. * Visit 1 (outpatient): Screening visit and blood alcohol level test * Medical history, physical and neurological examination, a blood test, and an electrocardiogram to measure heart function. Women who are able to get pregnant will have a urine pregnancy test. * Patients will consume 1.5 ounces of alcohol per drink (up to three drinks at least 30 minutes apart), and be tested to evaluate how the tremor responds. Researchers will draw blood to measure blood alcohol level about 1 hour after the first drink and closely monitor patients for signs of intoxication. * Inpatient examination * Preparation: Researchers will prepare a schedule to stop any tremor medications that patients might be on