When the wound is healed and while waiting for the restoration of function, measures are employed to maintain the nutrition of the damaged nerve and of the parts supplied by it.  The limb is exercised, massaged, and douched, and protected from cold and other injurious influences.  The nutrition of the paralysed muscles is further improved by electricity.  The galvanic current is employed, using at first a mild current of not more than 5 milliamperes for about ten minutes, the current being made to flow downwards in the course of the nerve, with the positive electrode applied to the spine, and the negative over the affected nerve near its termination.  It is an advantage to have a metronome in the circuit whereby the current is opened and closed automatically at intervals, so as to cause contraction of the muscles.

The results of primary suture, when it has been performed under favourable conditions, are usually satisfactory.  In a series of cases investigated by Head and Sherren, the period between the operation and the first return of sensation averaged 65 days.  According to Purves Stewart protopathic sensation commences to appear in about six weeks and is completely restored in six months; electric sensation and motor power reappear together in about six months, and restoration is complete in a year.  When sensation returns, the area of insensibility to pain steadily diminishes and disappears; sensibility to extremes of temperature appears soon after; and last of all, after a considerable interval, there is simultaneous return of appreciation of light touch, moderate degrees of temperature, and the points of a compass.

A clinical means of estimating how regeneration in a divided nerve is progressing has been described by Tinel.  He found that a tingling sensation, similar to that experienced in the foot, when it is recovering from the “sleeping” condition induced by prolonged pressure on the sciatic nerve from sitting on a hard bench, can be elicited on percussing over growing axis cylinders.  Tapping over the proximal end of a newly divided nerve, e.g. the common peroneal behind the head of the fibula, produces no tingling, but when in about three weeks axis cylinders begin to grow in the proximal end-bulb, local tingling is induced by tapping there.  The downward growth of the axis cylinders can be traced by tapping over the distal segment of the nerve, the tingling sensation being elicited as far down as the young axis cylinders have reached.  When the regeneration of the axis cylinders is complete, tapping no longer causes tingling.  It usually takes about one hundred days for this stage to be reached.

Tinel’s sign is present before voluntary movement, muscular tone, or the normal electrical reactions reappear.

In cases of complete nerve paralysis that have not been operated upon, the tingling test is helpful in determining whether or not regeneration is taking place.  Its detection may prevent an unnecessary operation being performed.