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

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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$lew days, just as in the other experiments, it ceased using the leg and held it up while running and walking. Even after the 90th day, a tendency was exhibited to flexor contracture, l)ut the object of the exj)eriment having been attained, the animal was not allowed to live longer. Thus in the case of tlie tliii'd expei'iment, the course of restoration was not markedly different from that of the cases in whicli the same nerves were divided and united in a crossing. The nerves which were divided and crossed, involved the entire supply of the muscles below the elbow joint, and of these nerves the entire supply of the flexors was crossed with the entire supply of the extensors. There was no excising of any part of the nerve, all the fibres were made to take part in the crossing. Thus, impulses descending the musculo-cutaneous, ulnar, and median nerves were diverted fi'om the flexor muscles, their normal destination, and instead directed down the pei'iphei'al segment of the musculo-spiral, Ijeing thus made to supply the extensors. On tlie other hand, the impulses for the extensor muscles descending the musculo-spiral M ere diverted at the crossing and descended the periphei'al segments of the musculo- cutaneous, median, and ulnar, thus supplying the flexors instead of the extensors. Thus the entire nerve sup])ly of tlie flexors was crossed \\'\t\i the entire nerve supply of the extensors. It was in order to ensure this that tlie musculo-cutaneous w;is included in the crossing, and the precaution turned oiit to have been necessary, as, when the animals were dissected, it was found that, in all, the musculo-cutaneous gave off at the elbow a large branch which joined the median nerve. This large communicating branch might have contained eflerent nerve fibres which contributed to the supply of the flexoi'S, and in Exjaeriment III. the physiplogical examination proved this to be the case. ()n comparing these resiflts with the results published by others, it is fomid tliat the only somewhat similar experiments published, witli which a comparison can be instituted, are those of Stefani (13) and of Cunningham (IG). In Kawa's (10) exjjeriments, the nerves divided were the posterior tibial and peroneal, and as one crossing only was made between the two nerves, the other two ends being widely excised, he had, therefore, as already mentioned, no case of nearly })erfect restoration of function. From this cause, and from the fact of the experiments having been conducted on the hind-limb, a fair comparison cannot be made. In the case of Stefani's experiments, the crossing was not exactly the same as in the experiments here recorded, not involving the entire supply to the muscles below the elbow. Thus, of the four exjDeriments of which he gives details, three consisted of crossing the median alone with the musculo-spiral. His remaining experiment, which consisted in a crossing of the median and ulnar with tlie musculo-spiral, and which was therefore more complete, was unfortunately vitiated, as the crossing did not turn out to be efiicient. In two of liis experiments, in one of Avhich, however, the crossing was not absolutely eflicient, the restoration of function! followed a course which was very closely the same as in the ex})eriments here recorded. Thus the first U 2$