Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Two Phenotypes of Postural Tremor Evaluated

Neurology; ePub 2018 Feb 23; Dirkx, Zach, et al

There are 2 distinct postural tremor phenotypes in Parkinson disease (PD), which have a different pathophysiology and require different treatment, according to a recent study. The first type, re-emergent tremor, is a continuation of resting tremor during stable posturing, and it has a dopaminergic basis. The second, pure postural tremor, is a less common type of tremor that is inherent to PD, but has a largely non-dopaminergic basis. In this combined observational and intervention study, researchers measured resting and postural tremor characteristics in 73 patients with tremulous PD by using EMG of forearm muscles. They performed an automated 2-step cluster analysis on 3 postural tremor characteristics: frequency difference with resting tremor, degree of tremor suppression after posturing, and dopamine response. They found:

  • 81% had re-emergent tremor and 19% had pure postural tremor.
  • This finding was manually validated (accuracy of 93%).
  • Pure postural tremor was not associated with clinical signs of essential tremor or dystonia, and it was not influenced by weighing.

Citation:

Dirkx MF, Zach H, Bloem BR, Hallett M, Helmich RC. The nature of postural tremor in Parkinson disease. [Published online ahead of print February 23, 2018]. Neurology. doi:10.1212/WNL.0000000000005215.

This Week's Must Reads

Tourette Syndrome, Tic Disorders, and Education, JAMA Neurology; ePub 2018 May 29; Pérez-Vigil, et al

RLS with PLMS More Common in Elderly Persons, Sleep; ePub 2018 Jun 1; Doan, Koo, Ogilvie, et al

Predicting Alpha-Synuclein Pathology Pre-Mortem, Parkinsonism Relat Disord; ePub 2018 May 17; Shprecher, et al

Excessive Daytime Sleepiness: Early Feature of DLB , Parkinsonism Relat Disord; 2018 May; Kasanuki, et al

HIV in HD Linked with Earlier Age of Symptom Onset, J Huntingtons Dis; 2018 Jun 1; Schultz, et al

Must Reads in Movement Disorders

Tourette Syndrome, Tic Disorders, and Education, JAMA Neurology; ePub 2018 May 29; Pérez-Vigil, et al

RLS with PLMS More Common in Elderly Persons, Sleep; ePub 2018 Jun 1; Doan, Koo, Ogilvie, et al

Predicting Alpha-Synuclein Pathology Pre-Mortem, Parkinsonism Relat Disord; ePub 2018 May 17; Shprecher, et al

Excessive Daytime Sleepiness: Early Feature of DLB , Parkinsonism Relat Disord; 2018 May; Kasanuki, et al

HIV in HD Linked with Earlier Age of Symptom Onset, J Huntingtons Dis; 2018 Jun 1; Schultz, et al