PERIPHERAL NERVE INJURIES AND THEIR TREATMENT1 1A lecture delivered in Post-Graduate Week, May, 1954, to the members of the Queensland Branch of the Australian Physiotherapy Association.

In order to get a clear picture of what happens when a nerve is injured, and what is involved in the loss and subsequent restoration of function, the structure of a peripheral nerve should be described. It is composed essentially of an aggregation of axons in a neurolemmal sheath. It may contain axons of one type only, as in a purely motor or a purely sensory nerve, or of both types, as in a mixed nerve. Within the sheath the axons are grouped together in a varying number of funiculi separated by supporting connective tissue. In any one nerve the funiculi are constantly undergoing redistribution to such an extent that if a length as short as two millimetres is excised the funicular pattern of each end might be quite dissimilar. Accurate end-to-end apposition of the original funiculi and axons is therefore not possible when portion of a nerve is lost. Because of the repeated division and reunion of funiculi a nerve may be divided as much as a quarter of the way through without significant loss of function. Similarly, axons may also divide and two divisions of the same axon may even pass along different nerves. That fact explains some of the anomalous findings in peripheral nerve injuries. When a nerve is divided, anæsthesia may occur temporarily in an area not supplied by that nerve. For instance, when the median nerve is divided, anaesthesia may occur in the distribution of the medial cutaneous nerve of the forearm