A comparison of the directionality of head tremor between essential and dystonic tremor

Abstract

An essential tremor (ET) is the most common movement disorder in adults. In clinical practice, it is often difficult to distinguish between an essential tremor with head tremor, or dystonic head tremor (DT) in cervical dystonia [1,2]. Therefore, we developed an instrumental method using an accelerometer to precisely measure and analyze head tremor to find a parameter evaluating the directionality of the tremor. Is head tremor in patients with ET one directional (typically “yes yes” or “no no” tremor) while DT is more complex ?The group of DT patients had a higher ratio of the first component to the second component PCA in comparison to patients with ET (p=0.02). There were no significant differences in frequency and power of tremor Results show that one direction tremor is more dominant in patients with dystonic tremor compared to essential tremor. This result challenges the standard thinking that ET is primarily in one direction only.