On the restoration of co-ordinated movements after nerve-crossing, with interchange of function of the cerebral cortical centres / by Robert Kennedy.
- Kennedy, Robert, -1924.
- Date:
- 1901
Licence: In copyright
Credit: On the restoration of co-ordinated movements after nerve-crossing, with interchange of function of the cerebral cortical centres / by Robert Kennedy. Source: Wellcome Collection.
Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.
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![II. Resume op Literature. The first recorded experiment on nerve-crossing was conducted by Flourens (1) as early as 1824. In a cock he cut the two chief nerves which go from the brachial plexus, the one to the superior aspect and the other to the inferior aspect of the wing. On section of these nerves the wing drooped completely, and its extremity could not he moved at all. He then crossed the nerves, joining the superior end of the one nerve with the inferior end of the other and vice ve):sd, and maintained them in this position ])y means of sutures. At tlie end of some months the animal liad perfectly regained the use of the extremity of its wing, which no longer drooped, and made use of it for flying quite as well as before the experiment. On exposing the nerves which had been crossed, he found that the position in which he had placed them had been maintained. He irritated the exposed nerves above, below, and on the seat of reunion, and found that irritability and conductivity were present; but he does not make it clear whether the point of reunion (point grossi de la reunion) was one which em])raced all four ends, or if there was a separate enlargement at the two seats of union. The objections which have been urged against this experiment are that no sufficient precautions were taken to prevent confluent union of all four ends, and that the nerves might therefore have reunited in their normal continuity in the common cicatrix ; that no sufficient description is given of the return of voluntary co-ordinated motion to enable the reader to judge if such had been restored (Schife) ; and, by Cunningham, that the recovery of function might have been due to the tensors of patagium, whose supply remained intact. We have, however, although the description is brief, the statement of Flourens tliat the wing was used for flying as well as before the experiment. That the conductivity of the nerves had been restored, and the crossing efiJective would appear from his statement, wlien I pinched the suj^erior nerve above the point of reunion, it was the muscles of the inferior aspect which contracted ; and it was, on the contrary, the muscles of the superior aspect of the wing which contracted when I pinched the inferior nerve, likewise above the point of reunion. Some years later it occurred to Schwann (2) that it was improbable after division and reunion of a nerve, that the corresponding ends of the nerve fibres had united as before the division, and he thought that probably many of the sensory fil^res might be brought to lie opposite motor fibres and unite witii them. With the perfect restoration of function which ensued after reunion of the nerve, Schwann thought that possibly some of the sensory fibres became i^aths for transmission of impulses to muscles. To test this, he divided in a frog both sciatic nerves, and after reunion and perfect restoration of function, he exposed the roots of the sciatic nerves, and irritated the posterior roots after severing them from the spinal cord, to ascertain if therel^y muscidar contractions coidd be evoked. But the result ^vas negative, as VOL. CXCIV.—B, ^](https://iiif.wellcomecollection.org/image/b21456513_0007.jp2/full/800%2C/0/default.jpg)
