Abstract
Through the courtesy of Drs. G. E. Brown and A. W. Adson, and the Mayo clinic, the writer was privileged to study the tonus of the muscles of the lower extremities of 4 patients who underwent bilateral extirpation of the lumbar sympathetic trunks, including the second, third, and fourth lumbar ganglia. This operation effectively eliminates the sympathetic innervation of the muscles of the lower limbs.
Tonus measurements, i. e., measurements of the resistance offered by the muscle to passive extension, were carried out, according to Spiegel's method, 1 on the quadriceps femoris muscles. The results of these measurements are expressed in tonus curves. Two of the patients were available for study both before and after operation. In these cases tonus curves of both quadriceps muscles were obtained both before and after sympathectomy. The other patients were available for study only after operation. One of the latter was subjected to the tonus measurements 6 days after operation. The other had undergone the operation 1 year previously.
The patient studied a year after sympathectomy is a young woman who underwent the operation for the relief of Raynaud's disease. The other three patients are men afflicted with thromboangiitis obliterans in both lower extremities. The studies carried out on these patients revealed no appreciable changes in muscle tonus referable to the disease process. The tonus curves obtained before sympathectomy lie well within the range of normal variation.
Tonus curves of normal extensor muscles, under normal innervation, obtained by the method employed, rise slowly at the beginning and then more rapidly as the length of the muscle is increased by passive extension. The slow rise of the curve at the beginning (Fig. 1, A and C) illustrates the “brake phenomenon” which is characteristic of extensor muscles, while in a postural attitude in which they are near their minimum normal length.
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