Investigations into the segmental representation of movements in the lumbar region of the mammalian spinal cord : excitation of the spinal cord, and direct excitation of the spinal nerve roots / by W. Page May ; [communicated by Victor Horsley].

  • May, W. Page (William Page), 1863-1910.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Investigations into the segmental representation of movements in the lumbar region of the mammalian spinal cord : excitation of the spinal cord, and direct excitation of the spinal nerve roots / by W. Page May ; [communicated by Victor Horsley]. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    complicated in structure and functions that slight varieties are to be expected in different members of the same series, or even, as in this case, there may be a clilference in the two sides of the same body Of interest is the effect of dividing various roots and noticing the change in the resultant movement elicited by stimulating a certain posterior root. This could be done in so many ways and with so many nerve roots that it is not necessary here to give more than the general conclusions to which they lead. One or two experiments, however, may be of interest. For instance, in one case stimulation of the 5th posterior lumbar root gave lateral movement of the side, contraction in the sartorius and hamstrings. The 5th anterior lumbar root was then divided, when from the posterior root, stimulated as before, movement in the gastrocnemius was added. That is, there ensued not only no diminution in the resultant movement, but a slight increase in another direction, as if part of the stimulus passing through the posterior root were prevented from passing out along all its normal paths, and, therefore, overflowed into another channel and gave an added effect. The 4th lumbar anterior root was then divided in the same side, when, the 5th posterior root being stimulated as before, flexion of the side, contraction of the sartorius, and extension in the knee resulted, this last being an additional new movement. Again, in another case, stimulation of the 7th posterior lumbar root gave flexion of the hip, slight extension of the knee, dorsal flexion of the foot, and inversion of tlie sole, whereas after division of the 7th anterior lumbar root excitation of the posterior root gave flexion of the hip, contraction of the hamstrings, extension of the knee, dorsal flexion of the ankle, strong flexion of tlie toes, and inversion of the sole, i.e., again an addition of new movements. o Following this up, the 7th anterior lumbar root was next divided, after which stimulation of the 7th posterior root gave adduction of the hip, contraction of the hamstrings, extension of the ankle, flexion of the proximal joints of the toes, and extension of the distal joints, and movement in the side and tail. After division, at intervals, of the 5th, 4th, and 3rd anterior lumbar roots no further difference in the movements resulting from stimulation of the 7th posterior root could be observed. But on dividing the 1st sacral anterior root, stimulation of the 7th posterior root gave only slight extension of the ankle, very slight flexion of toes, and movement in the tail and side, and finally, after dividing the 2nd sacral anterior root, excitation of the 7th posterior root evoked movejnent in the tail and side only. Minute Localization within the Excitable Area. In addition to the vertical distribution of the representation of movements in the lumbar enlargement (postero-external column) it was found that a minute differentia- tion could be made out in the lateral arrangement of the fibres in the column itself. Thus, in all the lumbar segments the following arrangement prevails:—