J Korean Neurol Assoc.
1998 Apr;16(2):188-192.
Electrocutaneous reflexes in Dystonia and Parkinson's disease
- Affiliations
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- 1Department of Neurology, Medial school, Chonbuk National University.
Abstract
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BACKGROUND AND PURPOSE: Dystonia is not understood and its pathophysiology is uncertain. The fundamental motor abnormality is an abnormality of muscle command signals, in such that the wrong agonists may be activated for too long, there is abnormal co-contraction of agonists and antagonist, and there is excessive and misdirected action of synergists and postural fixators. The reciprocal inhibition of H reflex has been studied for the evaluation of pathophysiology in tonus abnormalities. Lelli et al.(1991) found the similarities in reciprocal inhibition studies between dystonia and Parkinson's disease. He suggested that abnormalities of reciprocal inhibition appear to be a physiologic overlap between two disorders. There is, however, controversy about the results of reciprocal inhibition studies in both disorders. The cutaneous reflex study is another valuable test for the evaluation of the pathophysiology in tonus abnormalities. In an attempt to clarify the pathophysiologic mechanisms of both disorders, we performed cutaneous reflex tests and compared the findings of both disorders with those of the control group.
METHODS
50 normal persons as a control group, 10 patients with dystonia, and 10 patients with Parkinson's disease participated in this study. Cutaneous reflex responses were recorded in the first dorsal interosseous muscle following electrical stimulation of the digital nerves of the index finger.
RESULTS
Each mean amplitude of I1 of cutaneous reflex responses in patients with dystonia and in patients with Parkinson's disease is significantly decreased as compared with those of the control group.
CONCLUSION
The results from this study lead us to conclude that both dystonia and Parkinson's disease might have abnormalities of inhibitory supraspinal influences on spinal mechanisms.
