Clinical Trial: Ethanol Response in Essential Tremor: Clinical and Neurophysiological Correlates

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Ethanol Response in Essential Tremor: Clinical and Neurophysiological Correlates

Brief Summary:

Background:

- Essential tremor (ET) is a neurological disorder involving uncontrollable shaking, which over time can interfere with mobility and affect routine aspects of daily living. Several medications are used to treat ET, but these medications are often only partially effective and can have side effects. About two-thirds (66%) of people with ET have some relief from drinking alcohol, which suggests that alcohol affects the part of the brain causing the tremor. However, more research is needed to better understand the effects of alcohol or what areas of the brain might be important in the response.

Objectives:

  • To study to what extent alcohol is reducing tremor in a group of patients with essential tremor.
  • To use transcranial magnetic stimulation to study the effects of alcohol on essential tremor.

Eligibility:

- Individuals who are at least 21 years of age, have been diagnosed with essential tremor and have tremor in both hands, and can tolerate being off all medications for essential tremor for up to 4 weeks.

Design:

  • This study has one screening visit (1 to 2 hours), followed by one study visit (3 to 5 hours). Participants might be asked to also take part in one additional study visit (3 to 5 hours). The maximum period between the study visits is 3 months.
  • Participants will be screened with a medical history, physical examination, and blood tests. At this visit, participants will receive information about how to safely taper off their

    Detailed Summary:

    OBJECTIVE:

    The objective of this study is to investigate the clinical and electrophysiological correlates of the ethanol response in suppressing the tremor amplitude in patients with essential tremor (ET).

    STUDY POPULATION:

    85 patients with clinically diagnosed ET according to published diagnostic criteria will be entered into study phase 1. From the groups of participants in study phase 1, 12 responders and 12 non-responders will be invited back to participate in study phase 2.

    DESIGN:

    In study phase 1, the response to ethanol will be measured by a quantitative and qualitative approach using Essential Tremor (ET) spiral analysis during a standardized oral ethanol challenge. The clinical response will be correlated to breath-alcohol levels. Participants of study phase 1 will be selected based on their rate of response - dichotomized into a group of responders vs. non-responders - for study phase 2, during an IV ethanol challenge, brain excitability will be tested using transcranial magnetic stimulation (TMS).

    OUTCOME MEASURES:

    As the primary outcome parameter of study phase 1, we will determine the patients who respond to ethanol by tremor reduction versus patients without reduction of tremor intensities, as measured using spiral analysis of the dominant hand. Criterion for response will be operationally defined in a dichotomized fashion as reduction of tremor intensities, larger than the known diurnal variation of ET. Therefore, a patient will be considered a responder, if spirographic tremor amplitudes decrease by 35% or more at the time-point 60 minutes after an oral ethanol
    Sponsor: National Institute of Neurological Disorders and Stroke (NINDS)

    Current Primary Outcome:

    • Phase 1: To objectively determine the rate of ethanol responders vs. non-responders in a prospective sample of ET patients.
    • Phase 2: To evaluate changes of SICI in responding vs. non-responding ET patients during a continuous ethanol administration


    Original Primary Outcome:

    Current Secondary Outcome:

    • Phase 1: To correlate spirographic and clinical response in both hands with breath-alcohol-levels, acquired using a Breathalyzer at constant intervals after ethanol administration.
    • Phase 2: To evaluate changes additional TMS measures between groups


    Original Secondary Outcome:

    Information By: National Institutes of Health Clinical Center (CC)

    Dates:
    Date Received: September 11, 2010
    Date Started: August 30, 2010
    Date Completion: January 4, 2017
    Last Updated: April 21, 2017
    Last Verified: January 4, 2017