title: Testing for alcohol sensitivity of tremor amplitude in a large cohort with essential tremor.
abstract: BACKGROUND
  Improvement of essential tremor (ET) amplitude after alcohol ingestion is usually based on patient reports but a quantitative test for large numbers of patients is lacking and the percentage of ET patients with a detectable alcohol effect is therefore unknown.
  
  
  METHODS
  A validated and published alcohol home test was used in 104 ET patients. The Archimedes spiral was drawn before alcohol ingestion and at 4 time points after alcohol consumption and rated on a 10-point rating scale according to Bain and Findley. A second identical test without alcohol ingestion was performed by the same patients and evaluated by the same two raters to analyze the total variability of the spiral ratings.
  
  
  RESULTS
  Alcohol reduces tremor in ET patients as a group and a rebound effect with an increase in tremor intensity was found the next morning. Sex, family history of ET, diagnosis (definite vs. probable) and medical history of alcohol responsiveness do not predict the alcohol response. The minimal detectable difference in the spiral score was 2 due to spontaneous tremor fluctuations and inter-rater differences. The test demonstrated alcohol sensitivity of the tremor in 46% of the patients. Responsivity to alcohol could only be seen in patients with spiral scores above 3.
  
  
  CONCLUSIONS
  Alcohol sensitivity is a feature of ET in at least 46% of the patients. We could not find predictors for alcohol sensitivity. The minimal detectable change is 2 scores and alcohol responsivity was only detected in patients with baseline Archimedes spiral rating of ≥3.
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Hopfner
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Erhart
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Karina
authors.initials: K
authors.lastname: Knudsen
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Delia
authors.initials: D
authors.lastname: Lorenz
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Susanne A
authors.initials: SA
authors.lastname: Schneider
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Kirsten E
authors.initials: KE
authors.lastname: Zeuner
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany. Electronic address: g.deuschl@neurologie.uni-kiel.de.
authors.forename: Günther
authors.initials: G
authors.lastname: Deuschl
authors.affiliation: Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Kuhlenbäumer
mesh_terms: D000368:Aged; D020329:Essential Tremor / Q000139:chemically induced* / Q000175:diagnosis / Q000188:drug therapy*; D000431:Ethanol / Q000009:adverse effects* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D000431:Ethanol
keywords: Alcohol; Essential tremor; Tremor