Electrocutaneous reflexes in Dystonia and Parkinson's disease

J Korean Neurol Assoc > Volume 16(2); 1998 > Article

Journal of the Korean Neurological Association 1998;16(2): 188-192.

이긴장증과 파킨슨병에서의 전기피부반사

전북대학교 의과대학 신경과학교실

Electrocutaneous reflexes in Dystonia and Parkinson's disease

Man-Wook Seo, M. D.

Department of Neurology, Medial school, Chonbuk National University

Abstract

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. Key words: Cutaneous reflex, Dystonia, Parkinson's disease