Modulation of parkinsonian tremor by radial nerve palsy.
We analyzed rest and postural hand tremors in a Parkinson's disease patient who developed and recovered from a right radial nerve palsy at the spiral groove, and found that, despite complete paralysis of all extensors below the elbow, tremor frequencies remained unchanged while tremor amplitudes actually increased. This provides compelling evidence for a central generation of parkinsonian tremor frequency that is not influenced by the effects of peripheral modulation. In addition, the increase in tremor amplitudes may be due to disinhibited flexor activity caused by normally operating spinal segmental mechanisms interacting with central tremor generators programmed to alternate between antagonist muscles. Peripheral treatment of tremors--with muscle paralysis or botulinum toxin, for example--therefore may not be effective in stopping tremor oscillations in Parkinson's disease and may even worsen tremor amplitudes if all antagonists of a tremoring joint are not treated equally.
Pullman
S L
SL
Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY.
Elibol
B
B
Fahn
S
S
D000368:Aged; D004576:Electromyography; D006801:Humans; D008297:Male; D009431:Neural Conduction; D010243:Paralysis / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D011187:Posture; D011826:Radial Nerve / Q000503:physiopathology*; D014202:Tremor / Q000503:physiopathology*