(112) Wounded at Magersfontein. _Entry_, at the posterior border of the left mastoid process, 1/2 an inch above the tip; _exit_, through the right upper lip at the junction of the middle and outer thirds. There was considerable haemorrhage from the left ear. The injury was followed by complete deafness, and facial paralysis, which showed no sign of improvement.

There was complete anaesthesia over the area of distribution of the third division of the fifth nerve; this improved rapidly, and at the end of five weeks was hardly to be detected; neither at that time could any impairment of power on the part of the muscles of mastication be detected. No impairment of the sense of taste was noted.

(113) _Entry_, above the anterior extremity of the zygoma, bullet retained. Primary haemorrhage from ear. Complete facial paralysis and deafness. Anaesthesia over distribution of temporal branch of temporo-malar nerve, part of supra-orbital area, auriculo-temporal nerve, and small occipital cervical nerve. The muscles of mastication acted well. Ecchymosis below the right mastoid process.

(114) Wounded at Paardeberg. 300 yards. _Entry_, at the posterior border of the right mastoid process, 3/4 of an inch above the tip; _exit_, the inner third of the left upper eyelid. (Eye destroyed.) Complete right facial paralysis; deaf, on right side cannot hear tick of watch either held close or in contact. Purulent ot.i.tis media.

In this place I might mention two other cases of lesion of the seventh nerve secondary to wound of peripheral branches. In one a patient was struck by several fragments of lead from a bullet which broke up against a neighbouring stone. These for the most part lodged in the skin over the left orbicularis muscle, but one also lodged in the conjunctiva and was removed. Some ten days later the patient complained that he could not lift the upper lid. The levator palpebrae was normal, but spasm of the orbicularis held the eye firmly closed. The condition did not improve, and the patient was invalided home. He recovered later.

In another patient a bullet entered above the right zygoma and traversed the orbits, without wounding the globes. At the time no want of power of the muscles of the face was noted, but a year later there was evident weakness of the whole of the muscles of the right side of the face, with loss of symmetry.

In the former case the functional element was strong, but in both an ascending neuritis was probably present.

_Tenth nerve._--The pneumogastric was implicated in many wounds of the neck. I never observed an uncomplicated case, but laryngeal paralysis was temporarily present in two of the cases of cervical aneurism in which the wound crossed above the level of origin of the recurrent laryngeal branch, while in two others the recurrent branch itself was in close contact with the wall of the aneurism (p. 135). In all such cases signs of concussion or contusion of the nerve would be expected, judging from the similar results observed in the brachial nerves when the neighbouring artery was implicated. The only obvious symptoms occurring, however, were laryngeal paralysis and acceleration of the pulse. As the latter symptom was often observed in the cases of arterio-venous communication, wherever situated, and as the sympathetic nerve also lay in close contiguity to the wound track, it was difficult to ascribe it with certainty solely to the vagus lesion. In the two cases of high vagus injury the laryngeal paralysis steadily improved, and at the end of six months was apparently well; in the two others it persisted at the end of three months and a year respectively.

The nerve must have been very frequently damaged in wounds of the neck; it is possible that this injury may have been an important factor in the death of some of the patients with cervical wounds upon the field.

_Eleventh nerve._--I append the only case of localised spinal accessory paralysis I observed. This was one of my earliest experiences, and when I examined the neck, in the Field hospital, I a.s.sumed from the completeness of the sterno-mastoid and trapezius paralysis that the nerve was severed. The patient, however, made such a rapid recovery that it became evident that the nerve had been contused only, and that the recovery of function was not due, as is so often the case, to vicarious compensation by the cervical supply to the muscles.

(115) _Entry_, immediately to the right of the fourth cervical spinous process; _exit_, at the anterior border of the left sterno-mastoid opposite the angle of the mandible. The left shoulder was depressed, the head inclined to the injured side.

There was evident spinal accessory paralysis, and marked hyperaesthesia of the whole left upper extremity, most severe in the circ.u.mflex area. The hyperaesthesia gradually disappeared in a few days, and was clearly due to concussion and possibly slight contusion of the cervical nerve roots. The spinal accessory paralysis improved, so that the patient returned to the front at the end of a month: when I saw him some four months later the shoulders were held quite symmetrically.

The _twelfth nerve_ was occasionally damaged in wounds of the floor of the mouth. I saw no case of permanent paralysis.

_Injury to the systemic nerves._ _Cervical plexus._--Evidence of injury to the superficial branches of the cervical plexus was not rare; thus I saw cases of small occipital anaesthesia, and great occipital neuralgia, but none of motor paralysis from injury to the deeper muscular branches.

I take it that the smallness of the branches, and the multiple supply possessed by many of the muscles of the neck, would both take part in rendering certain evidence of the injury of an individual motor nerve rare.

_Brachial plexus._--Injury to this plexus in the neck was common; the main peculiarity observed was the partial nature of the damage inflicted.

Thus injury to a single nerve, or to a complex of two or more, was far more common than one implicating the whole plexus. Again, while complete paralysis might affect one set of nerves, another might simply exhibit signs of irritation in the form of hyperaesthesia or pain.

The wounds producing these injuries varied much in direction; thus some crossed the neck transversely, some were obliquely transverse, while others took a more or less vertical course.

These same remarks hold good in the case of the nerves of the arm. In the upper half, especially, complex injury was not rare, while in the lower third affection of individual nerves was more common. Another important difference must be mentioned in regard to the upper and lower segments of the course of the brachial nerves; they are not only more widely distributed below, but also more fixed in position, a fact antagonistic to the escape of the nerve by displacement and liable to expose it to more severe contusion.

The latter point holds good in the forearm also; here, individual injuries often occurred.

While at work in the Field hospital alone I gained the impression that the musculo-spiral nerve would not retain the unenviable character of being the most vulnerable nerve of the upper extremity, since the chances of each individual nerve seemed about equal, putting the question of the long course of the musculo-spiral nerve against the humerus out of question. This expectation was, however, not confirmed, since the musculo-spiral itself, if not primarily affected, was so often the seat of secondary mischief in fractures of the humerus. The posterior interosseous branch seemed to exhibit a similar vulnerability to slight injuries, to be referred to later under the external popliteal of the lower extremity. Again, in complex injuries of the brachial plexus, or nerve trunks, the musculo-spiral branch rarely escaped being a member, if not individually singled out.

Of the _thoracic nerves_ I have little to say. They must have been often injured in the thoracic wounds, yet, as far as my experience went, intercostal neuralgia was uncommon, or at any rate not a special feature. One observation of interest, however, does exist; in the cases in which the ribs were fractured by bullets travelling across them within the thorax, pain was distinctly a prominent feature. This was no doubt referable to the facts that in such instances the intercostal nerves were especially liable to direct injury, and that this was often multiple. On one occasion a crop of herpetic vesicles developed along the course of a dorsal nerve in an injury implicating a single intercostal s.p.a.ce posteriorly.

_Lumbar plexus._--Although not quite so well arranged to escape bullet wounds as the thoracic nerves, the lumbar, by reason of their deep position and the comparatively wide area they cover, together with the rarity of wounds taking a sufficiently longitudinal direction to cross the course of more than one or two branches, were also comparatively rarely damaged. I never saw an uncomplicated case of anterior crural paralysis, and rarely cruralgia. I think this is to be explained in two ways: first, that the trunk course of the nerve is short; secondly, that it lies in the inguinal fossa. The second fact is of importance, since wounds in this region were in my experience responsible for a considerable percentage of the deaths on the field or shortly afterwards. Such deaths probably occurred from internal haemorrhage from the iliac arteries, and it was in such cases that the anterior crural nerve stood in greatest danger of injury. I also never saw a case of localised obturator paralysis. On the other hand, anaesthesia or hyperaesthesia in the area of distribution of the lumbar nerves in the groin, the external cutaneous and the long saphenous in the thigh, were not uncommon. Hyperaesthesia developed in more than one case in which injury to the psoas had led to haemorrhage into the muscle sheath.

_Sacral plexus._--The sacral plexus is far more liable to extensive direct injury than either of the two preceding. Its cords are larger, gathered up into a much smaller s.p.a.ce, and more liable to injury, from the fact that the slope in which they lie is more readily followed by a bullet track. Again, the cords rest for a considerable portion of their course on a bony bed, a particularly dangerous position in gunshot wounds, since the nerves are not only exposed to the danger of direct wound, or pressure from bony spicules, but also readily receive transmitted vibrations secondary to impact of the bullet with the bone.

None the less I had few occasions to observe extensive injuries of the plexus. In one instance damage particularly affecting the lumbo-sacral cord occurred, but this was complicated by signs of irritation of the anterior crural and obturator nerves, as the result of retro-peritoneal haemorrhage and injury to the psoas muscle. Two cases in which the sacro-coccygeal plexus suffered isolated injury on account of their characteristic nature as gunshot injuries will be shortly quoted:

(116) _Sacro-coccygeal plexus._--_Entry_, at the junction of the middle and posterior thirds of the left iliac crest; the bullet pa.s.sed obliquely downwards through the pelvis to lodge 3 inches below the right trochanter major. Incontinence of soft faeces persisted for five weeks, and retention of urine during three weeks.

This patient subsequently died on the homeward voyage, but I am unable to say from what cause.

(117) _Entry_, over third sacral vertebra; _exit_, 2 inches from the median line, and 1-1/2 inch above Poupart's ligament on the anterior abdominal wall. Incontinence, with involuntary pa.s.sage of faeces, persisted during the first twenty-four hours, and for two days the urine had to be withdrawn with a catheter.

No further signs of nerve injury were noted.

The same explanation of the comparative rarity of injuries to the sacral plexus that has been already given in the case of the anterior crural nerve holds good--viz. that in a great many of the pelvic wounds involving the plexus early death followed from the severity of the concurrent injuries.

Injuries to the great sciatic nerve outside the pelvis, or to one of its const.i.tuent elements, on the other hand, formed one of the most familiar of the nerve lesions. The wounds giving rise to these were of the most diverse character; some crossed the b.u.t.tock in a vertical, transverse, or oblique direction; others travelled through the thigh in corresponding directions, while a third series involved both b.u.t.tock and thigh.

The size of the great sciatic nerve renders complete laceration by a bullet of small calibre a matter almost of impossibility; hence complete division may almost be left out of consideration in the case of this nerve. On the other hand, partial division, perforation, and severe contusion are each and all favoured by the same factor.

With an extended thigh the nerve is in a state of comparatively slight tension, and this may be still lessened if the knee be flexed. This factor, together with the density of the sheath of the nerve, favours the possibility of displacement, and this occurrence is more likely in the lower segment than in the upper, which is comparatively fixed in position.

Clinical experience appeared to ill.u.s.trate the importance of these anatomical factors, as the worst cases of sciatic injury that I saw were in connection with wounds of the b.u.t.tock or the junction of that segment of the trunk with the thigh.

The most striking observation with regard to the injuries of the great sciatic nerve was the comparatively frequent escape of the popliteal element and the severe lesion of the peroneal. This was so p.r.o.nounced as to amount to as high a proportion of peroneal symptoms as 90 per cent., and often when the whole nerve was implicated the popliteal signs were of the irritative, the peroneal of the paralytic type. When bullets crossed the popliteal s.p.a.ce, given wounds of equal severity in corresponding degrees of contiguity to the respective nerves, the peroneal element always suffered in greater degree. Again, the peroneal nerve symptoms were more obstinate and prolonged, and instances of ascending neuritis were more common than in the case of any other nerve of the lower extremity, and the trophic wasting of muscles was more marked.

The peroneal nerve, therefore, acquires the same unenviable degree of importance in the lower extremity enjoyed by the musculo-spiral in the upper. Here, again, we are confronted with the fact that the peroneal element of the great sciatic nerve is the more p.r.o.ne to idiopathic inflammations or toxic influences, and hence we can only a.s.sume it to possess a special vulnerability. The peroneal element is of course somewhat the more exposed, as lying posterior; but it seems unreasonable to a.s.sume that so large a proportion of the injuries can implicate the posterior segment of the nerve as to make the startling difference in the incidence of degeneration explicable. In this relation we may bear in mind that the muscles supplied by this nerve suffer most in the degeneration subsequent to anterior polio-myelitis, and again that in cerebral hemiplegia or spinal-cord injuries they are the last to recover. Unfortunately no explanation of these remarkable facts, so forcibly impressed by the large series of cases with peroneal symptoms seen in a short time, is forthcoming.

I may dismiss the other branches of the sacral plexus in a few words.

The small sciatic was occasionally injured in its course in the b.u.t.tock, and the small saphenous in the leg. When either element of the latter was injured, it was surprising how sharply the imperfections in the anaesthesia corresponded with the composite character of the nerve.

CASES OF NERVE INJURY

The following cases are added mainly to give some idea of the comparative frequency with which the individual nerves were injured, and also to exemplify the more common forms of complex injury met with.

Circ.u.mstances, unfortunately, did not always allow of extended observation at the time, and I have not been very fortunate in my attempts to obtain subsequent information on this series since my return. A certain amount of prognostic information is, however, furnished by some of the records, and I am very much indebted to my colleague, Dr. Turney, for help in this matter.

(118) _Brachial plexus._--_Entry_, 2 inches above the clavicle at the anterior margin of the trapezius; _exit_, first intercostal s.p.a.ce, 1 inch from the sternal margin. Heavy dull pain developed at once, extending down the upper extremity. A fortnight later this pain still persisted; there was lowered sensation in the ulnar area with formication, also lowered sensation in the internal cutaneous area of distribution; sensation in the lesser internal cutaneous area was normal. The patient went home with the nerve symptoms well at the end of a month.

(119) _Brachial plexus injury._--Wounded at Magersfontein.

_Entry_, at the anterior border of the sterno-mastoid opposite the pomum Adami; _exit_, through the ninth rib below and 1/2 an inch external to the scapular angle. Emphysema and considerable blood extravasation developed in the posterior triangle of the neck, also loss of power in the musculo-spiral distribution, but no anaesthesia. At the end of the first fortnight there was evident wasting of the muscles, but some power was returning in the triceps. At the end of a month the man left for England, with fair power in the triceps, but well-marked wrist-drop. A year later the wrist-drop still persisted.

(120) _Plexus injury._--Wound of _entry_, over pomum Adami; _exit_, below scapular spine, about centre. Complete median and musculo-spiral paralysis.

(121) _Median, musculo-cutaneous, and musculo-spiral nerves._--The wound traversed the axilla from just beneath the anterior fold; three weeks later a firm ma.s.s in the axilla corresponded to the wound track. Hyperaesthesia developed in the area of median distribution, with deep pain in the muscles.

There was rigidity of the biceps cubiti and slight wasting in the radial extensors. The patient improved slowly, and eventually was discharged and pa.s.sed out of sight.

(122) _Brachial nerves._--Wounded at Paardeberg. Range 500 yards. _Entry_, at the front of the arm, 2 inches below the junction of the anterior axillary fold; _exit_, a little lower, at the back of the arm, in the line of junction of the posterior axillary fold.

Considerable shock attended the primary injury; when reaction had taken place, complete motor and sensory paralysis was noted of the whole upper extremity, with the exception of some power of movement of the posterior interosseous group of muscles.

Three weeks later the patient could extend the wrist, but sensation was imperfect in the arm, and completely absent in the forearm and hand. The track was now hard and palpable, but there was no hyperaesthesia in any area; when the track was manipulated slight formication in the hand was experienced. The biceps and triceps were equally paralysed. There was no wasting in any of the muscles.

(123) _Brachial nerves._--Wounded at Modder River. _Entry_, through the anterior axillary fold at its junction with the arm; _exit_, on the posterior wall of the thorax, 1/2 an inch from the median line at a level with the angle of the scapula.

Complete musculo-spiral paralysis; haemothorax. Three weeks later, radial sensation returned; but the triceps was very weak, and wrist-drop was complete. There was some wasting of the muscles supplied by the median and ulnar nerves, and complete obliteration of the radial pulse. A year later the musculo-spiral paralysis still persisted.

(124) _Musculo-spiral and median._--Wounded at Magersfontein.

_Entry_, 3 inches below the anterior axillary fold, on the inner aspect of the arm; track pa.s.sed obliquely downwards behind the humerus to a point on the outer aspect of the arm 1-1/2 inch below the level of the entry. The humerus escaped injury. Musculo-spiral paralysis was complete; hyperaesthesia in the distribution of the median followed some days later. One month subsequently radial sensation had returned, and a feeling of numbness had taken the place of the median hyperaesthesia.

The triceps and marginal muscles were much wasted, and only interosseous extension was possible in the fingers.