I saw every degree of injury to the trunks, from notching to complete solution of continuity, and in some cases destruction and disappearance of pieces from one to two or more inches in length. Such lesions as the latter were most common in the forearm. In this segment of the limbs tracks of varying degrees of longitudinal obliquity are readily produced, whether the patient be in the upright or p.r.o.ne position, since the upper extremities are commonly in forward action whichever position is a.s.sumed.

The most peculiar form of injury consisted in perforation of the trunk without gross destruction of its fibres, and without in many cases prolonged or permanent loss of functional capacity. I cannot speak with any confidence as to the comparative frequency of occurrence of this form of injury, but judging by the a.n.a.logous perforations of the vessels, it is probably not uncommon in trunks large enough to allow of its production. The trunk nerves of the arm, and the great sciatic nerve, were probably the most frequent seats of such wounds. As, however, a very short experience of the futility of early interference in the case of nerve lesions warned me against exploration before a date at which observations of this nature were unsatisfactory, I gained less experience on this point than I could have wished.

In the case of completely divided nerves the development of a bulbous enlargement on the proximal end was constant, and very marked in degree.

I saw few cases in which primary effects could be certainly referred to pressure or laceration by bone spicules, excepting in some fractures of the humerus, and perhaps some injuries of the seventh nerve accompanying perforating wounds of the mastoid process.

IV. _Secondary implication of the nerves._--This was a striking characteristic in many at first apparently simple wounds of the soft parts. In such cases it was due to implication of the contiguous trunk in the process of cicatrisation, and its importance varied with the size of the nerve in question. In the smaller sensory trunks it was often evidenced by the occurrence of neuralgic pain, especially liable to be influenced by climatic changes; in the larger, by signs of more or less severe motor, sensory, and trophic disturbance. Musculo-spiral paralysis from implication in, or pressure from, callus in cases of fracture of the humerus was very frequent. This would naturally be expected from the extreme degree the comminution of the bone often reached, and the consequently large amount of callus developed.

The effect of cicatrisation of the tissues surrounding the nerves varied somewhat according to the degree of fixation of the individual nerve implicated. Thus if a nerve lay in a fixed bed some form of circular constriction resulted; if, on the other hand, the nerve was readily displaceable, the cicatrix often drew it considerably out of its course; in either case symptoms corresponding with those of pressure resulted.

_Symptoms of nerve lesion_.--These differed little in character from those common to such injuries in civil practice, except in the relative frequency with which they a.s.sumed a serious aspect. After all in civil practice nerve concussion is most familiar to us in the degree common after knocking the elbow against a hard object, and the same may be said in regard to the allied injury of contusion. It is in small-calibre bullet wounds alone that the occurrence of such severe and sharply localised injury to deep parts as was observed is possible.

_Concussion_.--Temporary loss of function was often observed in the limbs, corresponding to the distribution of one or more nerve trunks when wound tracks had pa.s.sed in their vicinity. Interference with function sometimes amounted to loss of sensation alone: in others to loss of both sensation and motor power. Such symptoms were of a transitory character, lasting for a few days or a week; if both sensation and motion were impaired, sensation was usually the first to be regained. In these cases secondary trouble was not uncommon, since the near proximity of the track to the originally affected nerve offered every chance for implication of the latter in the resulting cicatrix.

This sequence was often observed, and its symptoms are described under the heading of secondary implication below. Equally striking were the instances of concussion in the case of the nerves of special sense and their end organs, temporary loss of smell, vision, or hearing being not uncommon, often pa.s.sing off in the course of a few days with no apparent ulterior ill-effect.

One of the most interesting ill.u.s.trations of the occurrence of concussion was furnished by cases in which complete paralysis of a limb rapidly cleared up with the exception of that corresponding to a single individual nerve of the complex apparently originally implicated.

Instances of severe contusion or division of one nerve of the arm, for instance, accompanied by transient signs of concussion of varying degrees of severity in all the others, were by no means uncommon.

_Contusion_.--The symptoms of contusion were somewhat less simple, since, in addition to lowering or loss of function, signs of irritation were often observed. In the slighter cases irritation was often a marked feature, as was evidenced by hyperaesthesia and pain combined with loss of power. In cases in which pain and hyperaesthesia were primary symptoms, these were often transitory. I will quote an ill.u.s.trative case which, though affecting the nerve roots, is characteristic of the effects of slight contusion in the case of the nerve trunks in any part of their course:--

(107) _Contusion of cervical nerve roots_.--Range probably about 1,000 yards. Wounded at Belmont. Aperture of _entry_ (Lee-Metford), immediately posterior to the right fifth cervical transverse process; _exit_, immediately anterior to the s.p.a.ce between the third and fourth left cervical transverse processes. The movements of the neck were perfect, there was neither pain nor difficulty in swallowing. Extreme hyperaesthesia was present in both palms and down the front of the forearms. The grip in either hand was weak, this being possibly explained in part by the hyperaesthesia of the palms, as all movements of the upper extremities could be made, although not with full power. On the fourth day the condition was much improved on the left side, and at the end of a week the left upper extremity was normal; the right (side of entry, and therefore exposed to greater force from the bullet) improved more slowly, becoming normal only at the end of three weeks.

I observed an identical case of injury to the cervical roots, and many similar instances in injuries of the nerve trunks of the limbs in which the course was exactly parallel. In the more severe, pain was often added to hyperaesthesia.

In the most severe cases the signs corresponded in all particulars, except in the early entire loss of reaction of the muscles to electricity, with those of complete section. Loss of sensation and motion was immediate, complete, and prolonged, the limbs being lowered in temperature, flaccid, and powerless. General systemic shock was also severe. In the case either of plexus or multiple contusions, or where the injury was more local, correspondingly complete signs were present in the area supplied by the affected nerves.

In the cases in which the contusion was not of extreme degree, hyperaesthesia often developed as a later sign, and was probably due to the irritation of haemorrhage, when the sensory portion of the nerve began to regain functional capacity. The date of appearance of the hyperaesthesia varied from a few days to a week or later. It might then persist for weeks or many months.

In a few instances large blebs rose on the back of the hand, or patches of vesicles appeared over the terminal distribution of the nerve, pointing to early trophic changes.

The period of recovery varied greatly; in some instances of very complete paralysis, function was regained and became apparently normal at the end of three or four weeks; in others, even after severe wasting of muscles for weeks, rapid improvement occurred often suddenly, while in some there was no apparent recovery at the end of months. In cases of long-deferred improvement, wasting of the muscles became a very prominent feature; but this without complete loss of reaction of the muscles to electrical stimulation.

Recovery of sensation usually preceded by some time that of motion, the former often reappearing in some degree at an early date, and, even if very modified in character, it formed a most useful and valuable aid both in diagnosis and prognosis.

When in a position allowing of direct examination, the contused portion of the nerve sometimes developed a palpable fusiform thickening, manipulation of which might give rise to formication in the area of distribution--a favourable prognostic sign.

Many of the cases bore a very marked resemblance in character to those in which paralysis results from tight constriction of the limb, as in the arm after the application of an Esmarch's tourniquet.

_Laceration._--If incomplete, the signs corresponded very nearly to those of severe contusion, since partial section is impossible without the occurrence of the latter. The condition indeed was only to be distinguished by the partial nature of the recovery, and even this latter might be only more prolonged.

The same remarks hold good with regard to perforation of the nerve trunks; but, as regards function, these injuries are not so serious in prognosis as very much more limited transverse divisions or mere notching, and in some cases the disturbance of function was by no means profound or prolonged.

Absolute loss of reaction to electrical stimulus from above was the only pathognomonic sign of actual section, unless the position of the nerve was such as to allow of palpation, when the presence of a bulbous end at once settled the difficulty. In many cases of superficial tracks with division of such nerves as the long or short saphenous, the early development of bulbs in the course of the trunks gave positive information, and these were often observed.

_Traumatic neuritis._--This was a common sequence of contusion of the nerve itself, or of its subsequent inclusion in a cicatrix or callus. It was evidenced by hyperaesthesia both superficial and deep, pain, contracture, wasting of the muscles, local sweating, and the development of glossy skin.

Examples of this condition were seen in the case of nearly every nerve in the body. In frequency of occurrence, degree of severity, and in its selection of individual nerves considerable variation was met with. With regard to the two former points, personal idiosyncrasy, and degree of or peculiarity in the nature of the injury, are the only explanations I can suggest. Perhaps in some instances exposure to wet or cold in the early stages of the injury was of some import. Thus, I saw several severe cases of musculo-spiral neuritis in men who were wounded during the trying and wet march on Bloemfontein. I did not observe that suppuration or wound complications seemed important explanatory moments, as most of the cases occurred in wounds that healed rapidly.

With regard to the question of selection; the same nerves that appear particularly liable to suffer from idiopathic inflammations, toxic influences, or to be the seat of ascending changes (e.g. ulnar, musculo-spiral, and external popliteal), were those most often affected by secondary neuritis. Many of the most severe cases I saw were in the musculo-spiral nerve.

_Scar implication._--The signs of this most commonly commenced with neuralgia, or painful sensations when such movements were made as to put the cicatrix on the stretch. Although such neuralgia might not be constant, it was often observed to be troublesome when the patients were exposed to cold in sleeping out at night, or to extra fatigue, as in long marches. The results in many cases stopped at this point, but the size and wide distribution of certain nerves rendered even such slight symptoms of importance; while in others well-marked signs of neuritis declared themselves, such as glossy skin, pain, muscular wasting, and paralysis.

_Ascending neuritis._--In a few cases I observed very remarkable instances of ascending neuritis, after comparatively slight wounds. I will quote three of these as ill.u.s.trations and make no further remarks as to the symptoms. It will be observed that one is a case of ulnar, both the others of external popliteal, neuritis:--

(108) _Ulnar nerve: secondary ascending neuritis._--Boer wounded at Elandslaagte. Wound of hand, implicating anterior two-thirds of third metacarpal bone. This bone, together with the middle finger, was removed, and healing took place by granulation slowly.

The resulting gap allowed considerable overlapping of the fingers, and shortening of the corresponding digit; the index finger also became flexed as a result of destruction of the extensor tendons. Three months later the man was still in hospital in consequence of the tardiness with which the wound had healed: at this time pain was noted, which became very severe in the whole course of the ulnar nerve; superficial hyperaesthesia and deep muscular tenderness developed, but no wasting. Several crops of herpetic vesicles also developed over the distribution of the radial nerve in the hand. This pain was followed by spastic contracture, first of the ulnar fingers and later of the wrist and elbow, which could only be straightened by the application of considerable force. The limb was, therefore, kept straight by the application of a splint; and warm baths, and a blister applied over the course of the ulnar nerve, were resorted to: under this treatment the condition improved until the patient was well enough to be transferred as a prisoner, and I saw him no more.

(109) _Peroneal nerve branches._--Wounded at Colenso. _Entry_, at the anterior margin of the fibula 5 inches above the external malleolus; the track crossed the anterior aspect of the leg obliquely, to its _exit_ 1 inch above the centre of the ankle joint. Incomplete paralysis of the peronei muscles followed, combined with progressive wasting of the whole limb, which at the end of a month was marked, and then commenced to improve.

(110) In a second case the wound took a similar course in the centre of the leg, crossing the line of the branches of the musculo-cutaneous nerve. Motor paralysis of the peronei followed, together with general lowering of tactile sensation in the musculo-cutaneous area.

_Traumatic neurosis._--In connection with the cases just quoted, mention must be made of the fact that the functional element was often somewhat prominent. The influence of this factor was not to be neglected in case 108; again, its presence was a feature in cases 132 and 134, of injury to the sciatic nerve and of peripheral injury to the seventh nerve (p.

355). A remark has been made as to the occurrence of functional paraplegia on p. 337. Again, in the case of the organs of special sense.

Case 66, of injury to the occipital lobes, showed that a mixture of organic and functional phenomena might be a source of error, even in the determination of the visual field in the subject of an undoubted destructive lesion. On more than one occasion an injury was accompanied by loss of the power of speech; thus a patient who received a slight wound of the neck did not speak again until the application of a battery by my colleague, Mr. H. B. Robinson. A patient was also for a short time an inmate of No. 1 General Hospital, Wynberg, who had become deaf and dumb as a result of the explosion of a shrapnel sh.e.l.l over his head.

This patient also did not recover his powers until he returned to the mother-country.

In many other cases of nerve concussion or contusion, the recovery of power and sensation, or the disappearance of neuralgia or contractures, was so sudden and rapid after prolonged continuance of the symptoms, as to suggest a very strong functional element in their origin. The influence of the general shock to the nervous system received by the patients had an important bearing on these phenomena, and their interest from a prognostic point of view was very great.

INJURIES TO SPECIAL NERVES

_Cranial nerves._--It will be convenient first to make a few remarks concerning the nerves of special sense.

_Olfactory._--I observed temporary loss of smell on three occasions. In two instances this accompanied transverse wounds of the bones of the face in which the upper third of the nasal cavities was crossed; in the third a track pa.s.sing obliquely downwards from the frontal region pa.s.sed through the inner wall of the orbit, and crossed the nose at a lower level. In view of the small area of the olfactory distribution which was directly implicated, I was at first inclined to regard the loss of smell as dependent on the presence of dried blood on the surface of the mucous membrane, or on obstruction of the cavities from the same cause. Further observation, however, appeared to show that it was due to concussion of the branches of the olfactory nerve, since the loss of function persisted when the cavities were manifestly clear.

In all these cases we were confronted with the same difficulty which was experienced both in lesions of sight and hearing, the determination as to whether the concussion was of the branches or of the olfactory bulb.

When the symptom was the accompaniment of a fracture of the roof of the orbit, the possibility of concussion of the olfactory lobe was manifest.

In all, again, it was difficult to say what part the accompanying concussion of the branches of the fifth nerve took in the production of the symptom. In all three cases mentioned the return of function was gradual, but apparently fairly complete at the end of three weeks. In one it was noted that at first the patient was conscious of an odour before he was able to discriminate its actual nature; later he could determine the latter readily.

_Optic._--Some remarks concerning lesions of the optic nerve have already been made under the heading of wounds of the orbit. Concussion and contusion of the nerve both occurred, but I was unable to differentiate between the effects of these on the nerve itself, apart from the effects on the globe of the eye, which usually accompanied wounds of the orbit.

In some cases the nerve was directly divided in orbital wounds, and either pressure on or division of the nerve in the intra-cranial portion of its course, or as it traversed the optic foramen, was not uncommon.

_Auditory._--Loss of hearing was also not infrequent; thus it accompanied all three wounds of the mastoid process quoted under the heading of the seventh nerve, also two cases of fracture of the occipital bone near the ear quoted on p. 278. In all these instances it was impossible to attribute the deafness to lesion of the nerve alone, as the causative injury equally affected the internal ear, and in at least two the bullet implicated the tympanum as well in its course. The deafness was absolute in each case, and in none had any improvement occurred at the end of nine months. Deafness was a symptom in a certain number of the more severe cerebral injuries in which the course of the bullet was not so near to the internal ear: probably some of these were central in origin.

I only once observed any interference with the sense of taste.

_Remaining cranial nerves._--I have little to say regarding the _third_, _fourth_, and _sixth_ nerves. In the case of the third nerve, ptosis was occasionally seen in wounds of the skull involving the roof of the orbit, but the relative parts taken by injury to nerve and laceration or fixation of muscle respectively, were usually hard to determine. Again, the fourth and sixth nerves may have been damaged in some of the more extensive orbital wounds, especially those in which the globe suffered injury, but the signs under such circ.u.mstances were difficult to discriminate, and the injury was of slight practical importance, in view of the major injury to the globe itself.

_Fifth nerve._--Concussion, contusion, or laceration of the different branches of the three divisions of the fifth nerve were common in wounds of the head, but most frequent in fractures of the upper or lower jaws.

Localised anaesthesia was common from one or other of these causes, but for the most part transitory in the cases of contusion or concussion. I saw no case of entire loss of function in any one division, symptoms being mostly confined to certain branches, as the supra-orbital, the temporo-malar, the dental branches of the second division, the auriculo-temporal nerve, and the lingual, dental, and mental branches of the third division. I did not observe any cases in which modification of the special senses accompanied these injuries beyond those mentioned in the remarks already made on the subject of anosmia, and one case in which some modification of the sense of taste accompanied an injury to the floor of the mouth. It was a matter of surprise, considering the frequency with which subsequent neuritis was met with in the nerves generally, that trifacial neuralgia in some form was not more often met with. I never observed any serious case. Perhaps this is one of the fields in which a longer after-period may increase our knowledge.

Lastly, I never observed motor paralysis in the case of the third division, although sensory symptoms in some of the branches were common, evident proof that injuries to the trunk were rare.

_Seventh nerve._--Facial paralysis was most commonly observed in cases of wound of the mastoid process, apart from central cortical facial paralyses, of which several are quoted in the chapter on injuries of the head. All the wounds of the mastoid process were, in addition, accompanied by absolute deafness. I am sorry to be unable to give any details as to the electrical condition of the muscles in these cases, but I believe that in the great majority the paralysis was mainly the result of nerve concussion, since the perforations were clean in character and not obviously accompanied by comminution. Pressure from haemorrhage into the Fallopian ca.n.a.l may, of course, have been present, and in some instances, particularly those in which the bullet traversed the tympanic cavity, spicules of bone may have caused laceration. In every case, however, all the branches were equally affected; the paralysis was absolute, and in none did any improvement occur while the cases were under my observation.

The following are a few ill.u.s.trative examples:--

(111) Boer wounded at Belmont. _Entry_, immediately above zygoma; the bullet pa.s.sed through the temporal fossa, fractured the neck of the mandible, traversed the mastoid process, and emerged at the lower margin of the hairy scalp, 1 inch from the median line. Facial paralysis was complete, and there was no improvement at the end of ten weeks.