The primary type of tremor in essential tremor is kinetic rather than postural: Cross-sectional observation of tremor phenomenology in 369 cases

Background: Essential tremor (ET) is amongst the most commonly misdiagnosed neurological diseases. The current aim was to provide observational data on a basic characteristic of ET, namely, the relative severity of postural to kinetic tremor. Methods: A total of 369 ET cases were enrolled in a cross-sectional study. Postural tremor scores (0-3) and kinetic tremor scores (0-3) were assigned during a standardized neurological examination. Results: In the vast bulk of cases (~95%), kinetic tremor was more severe than postural tremor. In nearly one-in-three cases (32.8%), the kinetic tremor score was ≥1 points higher than the postural tremor score. Conversely, in only a few cases (~5%) was postural tremor even marginally (<1 point) more severe than kinetic tremor, and in no case was the postural tremor score ≥1 point higher than the kinetic tremor score. At each postural tremor score, nearly all cases had that amount of kinetic tremor or more. Conclusion: The primary type of tremor in ET is kinetic rather than postural. Recognition of the simple, empirical features of tremor phenomenology has potential diagnostic value for practicing clinicians.