Original Research ARTICLE
Postural and intention tremors: a detailed clinical study of essential tremor vs. Parkinson’s disease
- 1Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- 2Tufts University School of Medicine, Boston, MA, USA
- 3Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- 4Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- 5Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
Background: An estimated 30–50% of essential tremor (ET) diagnoses are incorrect, and the true diagnosis in those patients is often Parkinson’s disease (PD) or other tremor disorders. There are general statements about the tremor in these ET and PD, but published data on the more subtle characteristics of tremor are surprisingly limited. Postural tremor may occur in both disorders, adding to the difficulty. There are several anecdotal impressions regarding specific features of postural tremor in ET vs. PD, including joint distribution (e.g., phalanges, metacarpal-phalangeal joints, wrist), tremor directionality (e.g., flexion-extension vs. pronation-supination), and presence of intention tremor. However, there is little data to support these impressions.
Methods: In this cross-sectional study, 100 patients (ET, 50 PD) underwent detailed videotaped neurological examinations. Arm tremor was rated by a movement disorder neurologist who assessed severity and directionality across multiple joints.
Results: During sustained arm extension, ET patients exhibited more wrist than metacarpal-phalangeal and phalangeal joint tremor than did PD patients (p < 0.001), and more wrist flexion-extension tremor than wrist pronation-supination tremor (p < 0.001). During the finger-nose-finger maneuver, intention tremor was present in approximately one in four (28%) ET patients vs. virtually none (4%) of the Parkinson’s patients (p < 0.001).
Conclusions: We evaluated the location, severity, and directionality of postural tremor in ET and PD, and the presence of intention tremor, observing several clinical differences. We hope that detailed phenomenological data on tremor in ET and PD will help practicing physicians delineate the two diseases.
Keywords: essential tremor, Parkinson’s disease, tremor, clinical diagnosis, postural tremor, intention tremor
Citation: Sternberg EJ, Alcalay RN, Levy OA and Louis ED (2013) Postural and intention tremors: a detailed clinical study of essential tremor vs. Parkinson’s disease. Front. Neurol. 4:51. doi: 10.3389/fneur.2013.00051
Received: 08 April 2013; Paper pending published: 20 April 2013;
Accepted: 25 April 2013; Published online: 10 May 2013.
Edited by:Thomas Foki, Medical University of Vienna, Austria
Reviewed by:Fatta Nahab, University of Miami, USA
Stephan Klebe, University Hospital Würzburg, Germany
Copyright: © 2013 Sternberg, Alcalay, Levy and Louis. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Elan D. Louis, Unit 198, Neurological Institute, 710 West 168th Street, New York, NY 10032, USA. e-mail: firstname.lastname@example.org