49. Alchol test applied to neurophysiological study of essential tremor.

Essential tremor (ET) is the most common movement disorder, with a prevalence of 4% in patients aged >65 years. Alchol sensitivity is a secondary criteria for ET diagnosis. A discordance between patient’s perceived disability and real disability could be observed in real world, so requiring a most objective diagnostic tool to measure reproducible parameters. Neurophysiological tremor study (NTS) may be useful to this aim. NTS has been conducted by an accelerometer, placed in the distal extremity of the more involved upper limb, which measures the amplitude and the frequency of the tremor, at rest, during posture maintenance and voluntary movement. We performed NTS before and after alchol test. The amount of alchol to be dispensed to each patient is calculated by Widmark formula, in order to obtain an alcholemia within a range of 0.6–0.7 mg/dl. Five patients affected by ET have been registered. A significant (>50%) decrease of tremor’s amplitude has been observed, while a less evident effect on tremor’s frequency has been found. Alchol responsivness of neurophysiological registration parameters may be an adjunctive method to objectively quantify clinical improvement, and, according to our experience, to predict therapy responsiveness. [ABSTRACT FROM AUTHOR]