I saw no instance of wound of the _neural arch_ from a direct shot in the back in any of our men, neither was I ever able to detect an injury to the articular processes as a localised lesion.

Injuries to the _centra_ were very frequent, but differed extraordinarily in their importance. Perforation by bullets travelling at a relatively low grade of velocity, but still one sufficient to allow them to pa.s.s through the body, produced in many instances no symptoms whatever when the track did not lie in immediate contiguity to the spinal ca.n.a.l or perforate it.

In all the wounds which I had the opportunity of examining post mortem, the fracture was of the nature of a pure perforation of the cancellous tissue of the centrum, with no comminution beyond slight splintering of the compact tissue at the aperture of exit. In one instance the bullet pa.s.sed in a coronal direction so close to the back of the centrum as to leave a septum of only the thickness of stout paper between the track and the spinal ca.n.a.l. In this case signs of total transverse lesion were present. I never happened to meet with a case in which the ca.n.a.l was encroached upon from the front by displaced bone. In some cases at the end of six weeks there was difficulty in determining the position of the openings, and section of the bone was necessary in order to a.s.sure oneself as to the direction of the track.

In some instances the centra were pierced in the coronal direction with varying degrees of obliquity; in others the direction was more sagittal; in two of the latter the bullet was retained in the spinal ca.n.a.l. The tracks were sometimes confined to one vertebra, but often implicated two. In others the bullet pa.s.sed longitudinally through the thorax, grooving or perforating one or more centra.

The accompanying evidences of nerve injury varied from nil to those of pressure or irritation of the nerve roots, transient signs of spinal concussion, signs of contusion and haemorrhage, or to evidence of total transverse lesion. Instances of all these conditions will be quoted under the heading of injuries to the cord or nerves.

_Signs of injury to the vertebrae._--Separation of the spinous processes was often indicated by slight deformity, either evident or palpable, local pain, tenderness, mobility, and crepitus. In some cases these local signs were reinforced by evidence of cord injury. Fractures involving the laminae differed merely in the degree to which the above signs were developed. Fractures of the transverse processes were generally only to be a.s.sumed from the position and direction of the wounds, the a.s.sumption being sometimes strengthened in probability by evidence of injury to the cord and nerves.

Fractures of the centra were also frequently only to be a.s.sumed from the direction of the wound tracks, and possibly from evidence of nerve injury. When no paralysis supervened, interference with the movements of the back, or pain, was so slight as to be inappreciable, especially in the presence of concurrent injury to other parts, which was seldom absent. I only once saw any angular deformity from this injury, and that slight, and not apparent before the end of three weeks. In this particular a very striking difference exists between injuries from small-calibre bullets and larger ones such as the Martini-Henry. In the only instance of Martini-Henry fracture of the spine that came under my notice, the centrum was severely comminuted and deformity was obvious.

Still, as in so many particulars, the difference was only one of degree, since comminution of the centra in gunshot wounds has always been observed to be slight in nature compared with what is met with in the compression fractures of civil life.

A few words will suffice to dismiss the questions of diagnosis, prognosis, and treatment of the above injuries. The diagnosis depended on attention to the signs above indicated, the prognosis almost entirely on the concurrent injury to the nervous system, which will be considered later, and the treatment consisted in enforcing rest alone.

INJURIES TO THE SPINAL CORD ACCOMPANYING SMALL-CALIBRE BULLET WOUNDS OF THE VERTEBRae

_Anatomical lesions._--In introducing the subject of the nature of the lesions of the spinal cord and membranes, I should again enforce the statement that their character and degree, in comparison with the slight accompanying bone damage, are pathognomonic of gunshot wounds, and that these characters find their completest exemplification in injuries produced by bullets of small calibre, endowed with a high grade of velocity. Again, that the varying degrees of damage depend comparatively slightly on the position of the bone lesion, apart from actual encroachment on the ca.n.a.l, while the degree of velocity retained by the bullet at the moment of impact is all-important. In no other way are the divergent results to be explained which follow an apparently identical injury, in so far as extent, position, and external evidence of damage to the spinal column are concerned.

Injuries to the nerve roots of the nature of concussion and contusion, are dealt with in Chapter IX.

_Pure concussion_ of the spinal cord may, I believe, be studied from a better standpoint in the case of small-calibre bullet injuries than in any others, since in many instances it is, I think, possible to exclude any complications such as wrenches and strains of the vertebral column, and ascribe the symptoms to the pure effect of extreme vibratory force communicated to the cord by its enveloping bony ca.n.a.l. The condition must be considered under the two headings of slight and severe.

In _slight concussion_ the usually transient effects of the injury, and its happy tendency not to destroy life, place us in a state of uncertainty as to the occurrence of anatomical changes, since no opportunity of post-mortem examination occurred. The clinical condition included under this term corresponds with that implied in 'spinal concussion' in civil practice. One point of extreme interest, whether the subjects of small-calibre bullet spinal concussion will in the future suffer from the remote effects common to similar sufferers in civil life from other causes such as railway collisions, still remains for future determination. An ample field for such observations has at any rate been created by the present war.

In _severe concussion_ a far more highly destructive action is exerted.

This condition may be followed by complete disorganisation of the cord, accompanied or not by multiple parenchymatous haemorrhages into its substance. Either or both of these pathological conditions are produced by the impact of the bullet with the spine, given a sufficiently high degree of velocity, and it is difficult to separate clinically the resulting symptoms. This is a matter perhaps of less importance, since it stands to reason that a vibratory force, capable of rupturing the spinal capillaries, would at the same time damage the nervous tissue.

In speaking of concussion of this degree, it should be clearly recognised that a general condition, such as is indicated by the use of the term 'concussion of the brain,' is in no wise implied. The condition is really far more nearly allied to one of contusion, a strictly localised portion of the spinal cord undergoing the destructive process which affects the segments below only in so far as it interrupts the normal channels of communication with the higher centres.

Case 102 is an instance of such a lesion, the post-mortem examination showing clearly that the spinal ca.n.a.l was not encroached upon by the bullet. The cord in this instance appeared little changed macroscopically, and this fact was observed in other instances, both during operations and post mortem.

_Contusion._--This condition is very closely allied to the last. In cases 101 and 103 the spinal ca.n.a.l was as little encroached upon as in 102, but the bullet struck the somewhat elastic neural arch in each case, and post mortem an adhesion between the cord and the enveloping dura opposite the point at which impact of the bullet was closest suggests that, in spite of the escape of the bone from fracture, it may have been momentarily depressed to a sufficient degree to contuse the cord, or the latter may have suffered a _contre-coup_ injury. For these reasons the inclusion of the cases as instances of pure concussion is not warranted. In both Nos. 99 and 100 the neural arch had actually suffered fracture, and although the bone was not depressed or exercising pressure at the time of the autopsies, it was no doubt driven in temporarily at the moment of impact of the bullet.

At the post-mortem examinations of injuries of this nature it was common to find one to four segments of the spinal cord completely disorganised.

At the end of some five weeks, the common duration of life, the structure of the cord was represented by a semi-diffluent yellowish material, the consistence of which was so deficient in firmness as to allow the partial collapse of the membranes covering the affected portion, so as to exhibit a definite narrowing when the whole was held up (see fig. 79). In such cases traces of extra- or intra-dural haemorrhage sometimes still persisted.

_Haemorrhage._--This occurred as surface extravasation and in the form of parenchymatous haemorrhages. I saw the former both in the extra-dural and peri-pial forms, but never in sufficient quant.i.ty to exert a degree of pressure calculated to produce symptoms of total transverse lesion. Here again, however, it is difficult to speak with confidence since the conditions which regulate the tension within the normal spinal ca.n.a.l are so complicated and liable to variation, that it is very difficult to estimate the effect of any given haemorrhage discovered.

My friend Mr. R. H. Mills-Roberts described to me one fatal case under his care in the Welsh Hospital in which extra-dural haemorrhage was so abundant as, in his opinion, to have taken a prominent part in the production of the paralytic symptoms.

Examples of both extra- and intra-dural (peri-pial) haemorrhage are afforded by cases 99, 102, and 103; in none was it large in amount or widely distributed. The condition was probably also frequently a.s.sociated in varying degree with that to be immediately described below.

_Intra-medullary haemorrhage_ (_haemato-myelia_).--The importance of this condition is lessened in small-calibre bullet injuries by the fact already alluded to, that it is almost invariably accompanied by concussion changes. In one instance in which death took place at the end of eight days, partly as the result of concurrent injury, in a man in whom signs of total transverse lesion of the cord were present, the substance of the cord was found to be closely scattered over with haemorrhages of various sizes and extending for a longitudinal area of some three inches.

As to the frequency with which haemorrhage into the substance of the cord occurred, I regret to be unable to give an opinion. In the late post-mortem examinations I witnessed, a yellow discoloration of the softened cord was the only macroscopic evidence of haemorrhage.

Haemorrhages of this nature may, however, account for the grave paralytic symptoms in some cases of partial or total transverse lesion not due to direct compression or laceration.

The conditions of concussion, contusion, or haematomyelia were, I believe, responsible for at least nine-tenths of the cases in which a total transverse lesion was indicated by the symptoms. The extreme importance of realising this fact and the rarity of the production of symptoms by continuing compression both from the prognostic and the therapeutic point of view is obvious.

The a.n.a.logous injuries termed generally in Chapter IX. nerve contusion, although frequently accompanied by tissue destruction, may be followed by reparative change, and are capable of complete or almost complete spontaneous recovery; while the lesions in the spinal cord are permanent, and complete recovery is only witnessed in the parts affected by the remote pressure or irritation from blood extravasation, or in those influenced by concussion.

I include below short abstracts of all the cases of lesion of the spinal cord which terminated fatally, in which I had the opportunity of witnessing the post-mortem conditions. In a considerable proportion of the cases at the end of six weeks the spinal cord was softened over an area of from two to four segments in such degree as to have practically lost all continuity. Although the autopsies were made on patients who had died slowly and in summer weather, often twelve to sixteen hours after death, I think it can be but fair to a.s.sume, when the consistency of the remaining portion of the spinal cord is considered, that the softening was only in slight degree if at all exaggerated by post-mortem change. Again symptoms of secondary myelitis and meningitis had been observed in some of the fatal cases prior to death.

I had but one opportunity of observing a case in which a retained bullet exercised compression, and none in which this was due to displaced bone fragments. I also only once came across a case of complete section, but no doubt both bone pressure and section may have occurred with greater frequency amongst patients dying on the field or shortly after. The case of section is ill.u.s.trated in fig. 80. It will be noted that, although the section is complete, the bullet lies to one side of the ca.n.a.l, and hence the bullet, as fixed in its course by the bone of the centrum, directly struck but half of the whole width of the cord.

It was striking how little secondary change in the cord had occurred in the neighbourhood of the spot of division. This well ill.u.s.trates the comparatively slight vibratory effect of a bullet travelling with a degree of velocity insufficient to completely perforate the vertebral column.

_Symptoms of injury to the spinal cord._--In _slight spinal concussion_ these exactly resembled those of the more severe lesions, except in their transitory nature. They consisted in loss of cutaneous sensibility, motor paralysis, and vesical and rectal incompetence. The phenomena persisted from periods of a few hours to two or three days, return of function being first noticeable in the sensory nerves, and often with modification in the way of lowered acuteness, or minor signs of irritation, such as formication, slight hyperaesthesia or pain, pointing to a combination with the least extensive degrees of haemorrhage; later, motor power was rapidly regained. The subjects of such symptoms often suffered from weakness and unsteadiness in movement for some days or weeks; a sharp line of discrimination between such cases and those described in the next paragraphs is manifestly impossible.

_Spinal haemorrhage._--The symptoms of this condition developed differently according to whether concurrent concussion existed.

Occasionally very typical instances of pure haemorrhage were observed with transient symptoms:--

(96) A private in the Yorkshire Light Infantry was wounded at Modder River; the bullet entered between the eleventh and twelfth ribs, just posterior to the left mid-axillary line, emerging in the posterior axillary fold, at its junction with the right side of the trunk. On the second day after the injury the lower extremities became drawn up, the knees and hips a.s.suming a flexed position, and this was followed shortly by the advent of complete motor and sensory paraplegia, accompanied by retention of urine. Two days later, the patient again pa.s.sed water normally, and gradual and rapid return of both sensation and motor power took place. At the end of fourteen days no trace of the condition remained, and the patient was shortly after sent home.

The symptoms, however, were rarely so simple as in this example; it was very much more common to meet with an admixture of signs of primary concussion, or at any rate symptoms of radiation. The following is an extreme but excellent example of more complicated and prolonged effects:

(97) A lance-corporal of the Black Watch was wounded at Magersfontein at a range of from 400 to 500 yards. The bullet entered over the left malar bone 2-1/2 inches from the outer canthus, while the aperture of exit was 2-1/4 inches above the inferior angle of the right scapula, 3/4 of an inch anterior to its axillary margin.

Very shortly after the injury complete motor and sensory paralysis developed in both upper extremities, followed by the development of a similar condition in the left lower limb, and retention of urine and faeces, but the latter unaccompanied by the marked abdominal intestinal distension so characteristic in cases of total transverse lesion. The right side of the chest continued to work well, but the intercostals of the left side were paralysed. No disturbance of the normal action or condition of the pupils was noted. After the first few days the condition began to improve.

Three weeks later, the chest was moving symmetrically and well, sensation and motor power had returned in considerable degree in the left lower extremity, with marked increase in both the plantar and patellar reflexes; sensation had returned in both upper extremities, a slight amount of motor power was regained in the right, but the left remained entirely flaccid and incapable of movement.

At the end of a month power was regained over both bladder and r.e.c.t.u.m, some slight movement of the left thumb was possible, and a certain degree of hyperaesthesia developed over the back of the forearm.

At the end of six weeks there was little further alteration, but that in the direction of improvement. There was some wasting of the muscles of the left upper extremity, and this was most marked in the muscles supplied by the ulnar nerve.

At the end of ten weeks the patient had been up some days; he could stand and walk, but was unable to rise from the sitting posture without help. The plantar and patellar reflexes were much exaggerated, and there was ankle clonus, most marked in the left limb. The right upper extremity was normal, but weak; there was wrist-drop on the left side and the deltoid was wasted and powerless; on the other hand the fingers could be flexed, and although the elbow could not be, there were signs of returning power in the biceps, and some movements of the shoulder could be performed by the capsular muscles. It was remarkable that common sensation was more acute in the left than the right lower extremity, but I attributed this to the remains of hyperaesthesia on the left side. The patient left for home shortly after the last note.

In both these cases the absence of marked hyperaesthesia or pain points to medullary haemorrhage (haemato-myelia) as the pathological condition produced by the injury. In this particular they contrast well with case 94 quoted on page 315, where the degree of both hyperaesthesia and pain indicated a combination of pressure and irritation of the nerve roots by surface haemorrhage on the affected side. In case 97 the persistence for four weeks of paralysis of the bladder and r.e.c.t.u.m suggested medullary haemorrhage in addition, while the return of patellar reflex in the paralysed limb negatived the occurrence of an extensive destructive lesion.

In view of the extreme interest of these cases I will shortly detail one other in which the cauda equina alone was affected.

I must confess my inability to place the case definitely in the category either of concussion or medullary haemorrhage. As so often happened, both conditions probably took part in the lesion. The immediate development of the primary symptoms is no doubt to be referred to concussion, while the patchy nature of the prolonged lesion and gradual recession of the symptoms point to the presence of haemorrhages.

We find here the link most nearly connecting the spinal cord and the peripheral systemic nerves. Such a case goes far to show that the condition which I have in the next chapter often referred to as nerve contusion may in fact be produced by an injury far short of actual contact.

(98) A trooper in the Imperial Yeomanry, while advancing in the crouching att.i.tude, was struck by a bullet from his left front, at an estimated distance of 300 yards. The bullet traversed the right arm anteriorly to the humerus, entered the trunk in the line of the posterior axillary fold, 1-1/2 inch below the level of the nipple, crossed the thoracic and abdominal cavities, deeply striking the lumbar spine, and finally lodged beneath the skin over the venter of the left ilium. The skin was broken, but the force of the bullet was not sufficient to cause it to pa.s.s through, and it was later expressed from the wound by the surgeon. The bullet was a Mauser, and not in any way deformed, although it must at any rate have struck the spine and perforated the ilium.

Immediate paraplegia resulted, both sensation and motor power were completely abolished, but there was no trouble either with the bladder or r.e.c.t.u.m. No symptoms of injury to either thoracic or abdominal viscera were noted.

Three days after the injury sensation and some return of motor power were observed in the left extremity, and some power of movement in the toes of the right foot.

During the next eight weeks steady but slow improvement took place; during the last three weeks of this period he made the voyage to England. Ever since the injury some elevation of temperature was noted, a rise at night to 100 or at times to 102; for this no definite cause was discovered. In the tenth week the condition was as follows: The temperature has become normal. The patient has lost flesh to a considerable extent since the reception of the injury. The lower extremities are much wasted, especially the peroneal muscles. Patellar reflexes can be obtained, but the knee jerks are uncertain. Unevenly distributed paralysis exists in both lower extremities.

Left--Sensation fairly good throughout. Quadriceps very weak; does not react to electrical stimulation. Calf muscles act fairly. Anterior tibial and musculo-cutaneous groups are paralysed. Right--Quadriceps acts better than on left, muscles below the knee paralysed, and in the same area there is complete absence of sensation. The patient complains of shooting pains in both legs, and there is some deep muscular tenderness.

Three weeks later an abundant crop of vesicles appeared over the front of the right thigh and leg, above and below the knee.