The diagnosis of diseases of the spinal cord.

  • Gowers, W. R. (William Richard), 1845-1915.
Date:
1880
Catalogue details

Licence: Public Domain Mark

Credit: The diagnosis of diseases of the spinal cord. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    tended).* The irritability, on wliicli they depend, is due to and demonstrative of a muscle-reflex action which depends on the spinal cord. A true tendon-reflex may be excited by pinching the tendon, but this is a start of the whole limb, precisely such as results from a pinch of the skin. A clonus quite similar to that just described can be sometimes obtained in the peronei (a lateral foot-clonus), and also in the plantar muscles of the great toe—in each ease by passive tension. All have nearly the same time— about eight per second. It is of interest to note that modern physiologists know nothing of muscular tone except as developed by tension, and it is highly probable that the condition on which the Fig. 12.—Normal Foot-Clonus. (The tracing reads from right to left.) myotatic irritability depends, is identical with muscular tone. It is not, therefore, surprising that we are able, even in health, to get evidence of a tendency to rhythmical contraction. If a rhythmical contraction can be set up voluntarily, and gentle tension in the gastrocnemius maiutained, as by sitting on the edge of a chair with the ball of the foot resting on the ground, the contractions will go on involuntarily—a normal foot-clonus, which has precisely the same time (about six per second) as the morbid clonus (Fig. 12). A prolonged voluntary contraction * If it should ultimately be proved (which is very improbable) that so short an interval as one-fortieth of a second is sufficient for a reflex action, and that each contraction is reflex, the term myotatic will still bo accu- rate, since it will remain true that tension is essential for the production of these contractions.