Conditions: Essential Tremor
Keywords: Essential Tremor Octanol Octanoic Acid Ethanol Accelerometry
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 29
Healthy volunteers: no

Brief summary:
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. Patients may not drink alcohol or eat or drink anything with caffeine, including chocolate, for at least 2 days before admission.
* Day 1: Vital signs, blood (and urine pregnancy) tests, and electrocardiogram. Patients will be asked to wear a tremor monitor, similar to a wristwatch. Patients will also have IV lines inserted for blood draws.
* Days 2 and 3: Randomized study medication (octanoic acid on one day, placebo on the other day). Patients will fast before taking the drug, but will be allowed to eat and drink after the tests are completed (around noon).
* Blood will be drawn before taking the study drug and again (a total of nine times) after taking the drug.
* Tremor will be measured during the study, before and after taking the drug.
* Visit 2 (outpatient): 4 to 7 days after discharge
* Blood test and an electrocardiogram, and a series of questionnaires regarding the study.

Detailed description:
OBJECTIVE:

We propose a study to examine the safety and efficacy of octanoic acid in essential tremor (ET).

STUDY POPULATION:

We will study 19 adult subjects with ethanol-responsive ET.

DESIGN:

Octanoic acid will be tested in a double-blind, randomized, placebo-controlled, cross-over design in 19 patients with essential tremor. The active study medication and placebo will be administered as oral single morning doses on consecutive days in a randomized sequence. All subjects will receive a dose that was defined as being safe according to available toxicity data (4mg/kg) and will be monitored closely during the total inpatient study phase of three days (day 0: baseline; days 1-2: active study days).

OUTCOME MEASURES:

The primary outcome measure for this study will be the effect on tremor power of the dominant hand, 80 minutes after administration of the study substance, compared to placebo. Tremor power will be measured using accelerometry with loading to test central tremor component. Secondary outcome measures include recordings of tremor power as measured by accelerometry at multiple other time points up to 300 min after administration, also recorded from the non-dominant hand and without loading. The change in tremor severity documented by spirography and actigraphy as well as data collected regarding drug safety (laboratory testing, documentation of vital signs, adverse events questionnaire and intoxication scale) as well as the pharmacokinetic and pharmacodynamic properties will act as further secondary outcome parameters.

Arms:
arm 1: None arm 2: None

Interventions: intervention 1: Octanoic Acid intervention 2: Placebo
Intervention descriptions: intervention 1: 4mg/kg intervention 2: identical capsules

Protocol document: