Affordable Access

Publisher Website

Amitriptyline enhances the central component of physiological tremor

Authors
Journal
Journal of Neurology Neurosurgery & Psychiatry
0022-3050
Publisher
BMJ
Publication Date
Volume
70
Issue
1
Identifiers
DOI: 10.1136/jnnp.70.1.78
Keywords
  • Papers
Disciplines
  • Biology
  • Medicine

Abstract

OBJECTIVES—Postural tremor is a regularly encountered side effect of amitriptyline which can be strong enough to cause discontinuation of therapy. The aim was to characterise amitriptyline induced tremor and to assess if the central or reflex component of physiological tremor was modulated by this drug.
METHODS—The postural hand tremor was measured in 15 patients on a clinical rating scale, by power spectral analysis of accelerometer, forearm flexor, and extensor EMG before and after the beginning of amitriptyline treatment for major depression or chronic pain syndrome. A coherence analysis between flexor and extensor muscles on the same side was performed.
RESULTS—There was a clinically visible increase in postural tremor in a third of these patients. The tremor amplitude measured by accelerometer total power increased in every patient under amitriptyline. The EMG synchronisation as reflected by significant peaks in the flexor or extensor spectrum generally occurring at higher frequencies (8-18 Hz) than the accelerometric tremor frequencies (6-11 Hz) did not change. The number of patients with a significant flexor-extensor coherence in the 7-15 Hz range increased significantly under amitriptyline, the frequency bands of significant coherence corresponded with the EMG frequencies, and both were independent of changes to the hand's resonant frequency by added inertia.
CONCLUSIONS—An enhancement of postural tremor under amitriptyline is a common phenomenon although not always clinically apparent. The increase in EMG-EMG coherence indicates an increased common central drive to the motor units as its frequency is not influenced by peripheral resonance or reflex mechanisms. This is the first account of a drug induced enhancement of the central component of physiological tremor.



There are no comments yet on this publication. Be the first to share your thoughts.

Statistics

Seen <100 times
0 Comments

More articles like this

Amitriptyline enhances the central component of ph...

on Journal of Neurology Neurosurg... January 2001

Genetical components of physiological tremor.

on Journal of Medical Genetics June 1975

Genetical components of physiological tremor.

on Journal of Medical Genetics Jun 01, 1975
More articles like this..