Chapter IX: Injuries to the Peripheral Nerve Trunks (2)

(129) _Ulnar and musculo-cutaneous nerves._--_Entry_, back of
forearm; the bullet passed between the bones and was retained
at the posterior aspect of the arm. Three weeks later the hand
was glossy and stiff, the fingers extended and adducted, the
thumb was held stiffly in the palm with no power of extension.
The forearm was held semiprone, and the elbow flexed by a rigid
biceps. Six months later the same position was maintained, but
the contracture disappeared under an anæsthetic.

(130) _Median and posterior interosseous._--_Entry_, over the
external margin of the radius at the centre of the forearm;
_exit_, at the inner margin of the olecranon 1-1/2 inch below
the tip. Lowered cutaneous sensation in median distribution,
and loss of median flexion of wrist and fingers. Complete
wrist-drop. The triceps supinator longus and extensor carpi
radialis longior were perfect. Twelve days later the wrist
could be raised into a direct line with forearm, but there was
no change in the median symptoms. A week after this the
anæsthetic median area became hyperæsthetic both as to skin and
on deep pressure over the muscles.

(131) _Sacral plexus. Great sciatic nerve._--Wounded at Modder
River. _Entry_, in left loin; _exit_, at lower margin of
buttock. The wound was followed immediately by complete
peroneal paralysis, both motor and sensory. Fourteen days later
hyperæsthesia developed in the area of distribution of the
internal popliteal nerve, the superficial pain being greatest
in the sole; the muscles of the calf were also very tender on
manipulation. The pain increased, and at the end of twenty-four
days the patient's sufferings were so great that Mr. Thornton
cut down upon and exposed the nerve. It was found embedded in
firm cicatricial tissue close to the sciatic notch; this
compressed the nerve to such a degree that a waist was apparent
upon it.

The nerve was freed and resumed its normal outline. For a few
days the patient was much relieved, but the neuralgia then
returned in greater intensity than ever. Morphia was injected
hypodermically, and other hypnotics employed, but with little
effect, the patient developing the hysterical condition so
common in the subjects of severe sciatica. Some five weeks
later a sudden improvement took place, the morphia was
decreased, and the patient became sufficiently well to return
to England, but there was still deep tenderness in the calf,
and well-marked hyperæsthesia of the sole.

A year later the patient had been discharged from the Service,
but was earning his living in a shop. He walked fairly well,
but still with foot-drop, and complained of tenderness in the
sole. I am indebted to Dr. Turney for the following report on
the condition of the muscles.

Calf muscles practically normal. In the anterior tibial and
peroneal groups the faradic irritability is much diminished,
that in the peroneus longus being the lowest of all.
Contraction can be induced in the extensor longus hallucis,
extensor longus digitorum, and peroneus brevis; but reaction is
doubtful in the case of the tibialis anticus and peroneus
longus.

With the galvanic current contraction is sluggish, and the
irritability diminished. No serious changes are present except
in the peroneus longus. ACC > KCC at 10 M. A.

(132) _Great sciatic._--_Entry_, at outer aspect of the thigh,
just above the centre; _exit_, at the junction of the inner and
posterior aspects of thigh, about 2 inches lower. The wound was
produced by a ricochet bullet, and beyond the perforation of
the sciatic nerve the femur was fractured obliquely (see plate
XVI.). Hyperæsthesia of the sole was noted early, and when I
saw the patient three months later, there was wasting of the
muscles of the leg, and foot-drop, although he walked with a
stick.

These symptoms persisted, and on his return to England an
exploration was made by Sir Thomas Smith, and the two fragments
of mantle seen in the skiagram were removed from the substance
of the sciatic nerve. Eight months after the injury, the
patient still walked with foot-drop; there was modified
sensation in the musculo-cutaneous area, and a feeling as if
the bones of the foot were uncovered when he walked. The
circumference of the affected leg was more than 1 inch less
than that of the sound one. Steady but slow improvement was
taking place.

(133) _Great sciatic_.--In a third patient with a buttock
track, the symptoms were identical with those observed in case
131. In this an exploration showed that the nerve had been
perforated. Although the symptoms were never so severe as in
No. 131, yet recovery was very much slower and less complete,
the muscular weakness remained more marked, and the skin
exhibited more evidence of trophic lesion. Some contracture of
the knee and rigid foot-drop took place, and at the end of
twelve months the patient walked poorly with a stick.
Improvement is, however, continuing.

(134) _Great sciatic_.--Wounded at Ladysmith. _Entry_,
immediately below left buttock fold; _exit_, at anterior aspect
of thigh, 3-1/2 inches below Poupart's ligament. The left leg
was paralysed, and patient was sent down to the Base, where he
remained two months. The wound closed by primary union, the
paralysis improved, and the man rejoined his regiment. After he
had been in camp four days, his leg gave way, and he returned
to hospital, where he contracted enteric fever. Later, he was
sent home, and eight months after the reception of the injury
his condition was as follows:

Left lower limb somewhat wasted, a diminution of 1 inch in the
circumference of the leg and 1/2 an inch in the thigh being
found. The patient walks with foot-drop, and the flexor muscles
of the knee are weak. On examination the peroneal muscles
reacted but sluggishly to faradic irritation. There is complete
anæsthesia of the foot to above the ankle, and up to the knee
tactile sensation and appreciation of pain were dulled. The
left plantar reflex was absent, the right slight, the left
patellar reflex was abnormally brisk. There was neither ankle
nor patellar clonus, and the other reflexes were present and
normal. The gait was spastic, and the patient was more troubled
by a contraction of the calf muscles, which prevented his
putting the heel to the ground, than by the foot-drop.

Beyond these local phenomena there was marked tremor of the
upper extremities on any exertion, and slight lateral
nystagmus. The patient was not sure that this had not been
present ever since he recovered from the enteric fever, but it
was sufficiently marked to give rise to the suspicion of the
development of disseminated sclerosis.

The patient was a hard-headed, sensible man. He remained in the
hospital under the care of Dr. Turney, to whom I am indebted
for notes of the case, forty-six days. During this period he
was treated by faradic electricity, and, with some checks,
notably the development of passive effusion into the left
knee-joint, and a fugitive attack of redness over the dorsum of
the foot, both suggesting trophic changes, steadily improved.
The anæsthesia became limited to the outer half of the leg, at
the end of one month was limited to the dorsum of the foot
only, and at the end of six weeks entirely disappeared.
Meanwhile the tendency to drawing up of the heel by the calf
muscles became less, and the gait improved. The man left the
hospital at the end of two months, very satisfied with his
condition, although the tremor of the hands was still present
in a lessened degree.

(135) _External popliteal._--Wounded at Magersfontein, 250-300
yards. _Entry_, at the outer side of the thigh, 5 inches above
the lower extremity of the external condyle; _exit_, at the
inner margin of the adductors, at a level 4 inches higher in
the thigh. The track crossed behind the femur. Complete
peroneal motor paralysis and anæsthesia, except in the hinder
part of the region supplied by the mixed external saphenous.
Slight hyperæsthesia of the sole. Improving at the end of three
weeks, but paralysis still nearly complete.

(136) _External popliteal._--Wounded at Magersfontein. _Entry_,
5 inches below the highest part of the right iliac crest, on
outer aspect of hip; _exit_, at the posterior margin of the
gracilis, 2 inches from the perineum. Complete peroneal
paralysis followed, which rapidly improved, and on the
twenty-second day was nearly well.

(137) _Internal popliteal. Secondary anæsthesia_.--_Shell_
wounds of the right popliteal space. Wounded at Belmont.
Anæsthesia of the outer side of the calf, the leg and sole of
foot. No motor paralysis. As cicatrisation progressed, the
anæsthesia became more marked and was complete over the whole
of the external saphenous area.

(138) _Internal popliteal._--Wounded at Paardeberg. 400-500
yards. _Entry_, about the centre of the outer half of the
patella; _exit_, at the centre of the calf, about 2 inches from
the popliteal crease. Five days after the injury severe burning
pain developed in the sole. A fortnight later the pain was much
less severe, but varied in degree with the heat of the weather,
being worse when cool. At this date, however, rubbing became
comforting.

(139) _External popliteal._---Wounded at Magersfontein.
_Entry_, 1 inch above the upper end of the internal margin of
the patella; _exit_, at the margin of leg, just below the outer
tuberosity of the tibia. Complete peroneal paralysis followed
the injury. A month later the nerve was bared and found
slightly thickened. An improvement in cutaneous sensation
followed quickly, and a much slower improvement in the motor
power commenced.

(140) _External popliteal nerve._--Wounded at Beacon Hill. A
_bayonet_ entered over upper quarter of fibula, and passed
between the bones of leg into the calf. An aneurismal varix of
the calf vessels developed, also incomplete peroneal paralysis.
The scar was raised from the nerve (Major Simpson, R.A.M.C.)
six weeks later, and at the end of a fortnight the power and
sensation were both much improved and the patient returned to
England.

(141) _External popliteal._--Wounded at Modder River. _Entry_,
1/2 an inch above the internal border of the patella; _exit_,
1-1/2 inch from the head of the fibula and over that bone. The
wound was followed by peroneal paralysis. Six weeks later
sensation was still diminished in the anterior tibial and
musculo-cutaneous nerve areas, and marked foot-drop, little
improved, persisted. The patient came to England, and at the
end of twelve months is reported as very little improved.

(142) _Anterior tibial._--_Entry_, 1 inch in front and below
the external malleolus; _exit_, at the centre of the sole, just
anterior to the bases of the metatarsal bones. Wasting and
paralysis of extensor brevis digitorum.

(143) _Small sciatic and small saphenous._--Wounded at
Magersfontein. 200 yards. Two wounds: (i) _Entry_, below the
centre of the twelfth rib on the left side; _exit_, immediately
to the left of the buttock furrow at upper part, (ii) _Entry_,
in the right loin, midway between the last rib and iliac crest;
_exit_, just within the centre of the left buttock; the two
wounds crossed diagonally. Hyperæsthesia in area of
distribution of small saphenous and small sciatic nerves, which
rapidly improved.

(144) _Lumbar plexus._--Boer, wounded at Magersfontein.
_Entry_, eleventh interspace, posterior axillary line; _exit_,
tenth interspace, right mid-axillary line. Impaired sensation
in area of distribution of external cutaneous and crural branch
of genito-crural nerves. At the end of a fortnight anæsthesia
was less apparent, but a feeling of numbness persisted, which
soon disappeared.

_Prognosis and treatment._--In considering the prognosis in cases of nerve injury, several of the points already raised as to the nature of the lesion are of importance. Short of actual section, it may be broadly stated that no lesion is too serious to render ultimate recovery impossible.

In cases in which the injury has been produced by a bullet fired at a short range, or in which contact with the nerve has been close, the return of functional activity is very slow. In such instances the condition probably resembles that in which a divided nerve has been sutured, with the additional disadvantage that a considerable portion of the nerve, both above and below the point actually struck, has been destroyed as far as the conduction of nervous impulses is concerned. This may reasonably be concluded in the light of the evidence offered by the injuries of the spinal cord, in which several segments usually suffered if the velocity of the bullet was great, and also if the fact is remembered that, when thickening takes place, a considerable length of the nerve is usually implicated.

Recovery is notably slow in the case of certain nerves, _e.g._ musculo-spiral and peroneal, even when the injury has not been of extreme severity. Again, these same nerves are apparently more seriously affected by moderate degrees of damage than are others.

As favourable prognostic elements we may bear in mind: low velocity on the part of the travelling bullet, and with this a lesser degree of contiguity of the track to the nerve. The early return of sensation is a favourable sign, and in this relation the development of hyperæsthesia, whether preceded by anæsthesia or no, points to the maintenance of continuity of, and a moderate degree of damage to, the nerve. The early return of sensation, even if modified in acuteness, was always a very hopeful sign; also the production of formication in the area of distribution of the nerve on manipulation of the injured spot. As in the case of nerve injuries of every nature, the disposition and temperament of the patient exerted considerable influence on the course of the cases.

Complete section of the nerves in these bullet wounds only obtained special importance in two ways: first, in that a considerable portion of the trunk might be shot away in oblique tracks, and, secondly, in that very severe contusion might affect the nerve for a considerable distance beyond the point actually implicated. In point of fact, complete section when treated by suture was often more rapidly recovered from than an injury in which only a portion of the width of a trunk was divided. This was no doubt to be explained on the theory that the contiguous portion of the nerve suffered less when tension and resistance were lessened by complete severance of the cord.

_The treatment_ of slight nerve contusion was simple; rest alone was necessary, and in the course of hours or days paralysis was recovered from. The symptoms were most troublesome in patients of a neurotic temperament, or those who had suffered from severe systemic shock.

In severe concussions and contusions the first care had to be devoted to the discrimination of the lesion from that of division. A period of rest then needed to be followed by one of massage and movement, to maintain the nutrition of the muscles. In a considerable portion of the cases a stage of neuritis had to be expected. In all cases, either of severe concussion, contusion, or complete section, accompanied by the fracture of a bone, especial care was necessary that the bandaging and fixation of the limb were not sufficiently tight to add the dangers of muscular ischæmia to those of the nerve injury already present.

Neuritis, whether dependent on local injury, implication in the scar, pressure from callus, or of the ascending variety, needed the same treatment: rest, preservation of the limb from cold or damp, and the local application of anodynes, as belladonna, or hot laudanum fomentations. In some cases a general anodyne, as morphia, was preferable; then always to be used with caution, as the patients soon craved inordinately for it, and were unwilling to give it up. Later, local blisters in the line of the nerve trunk, careful massage and exercise when muscular and cutaneous tenderness had subsided, the application of the continuous current to the nerves, and perhaps faradisation of the muscles, were all useful.

Splints were often temporarily required to resist contracture, or the assumption of false positions; in either case they needed to be frequently removed, and movement &c. made, in order to avoid any chance of troublesome stiffness.

_Operative treatment._--Early interference was only warranted by positive knowledge that some source of irritation or pressure could be removed; thus a bone spicule, or a bullet, or part of one, particularly portions of mantles.

In case of contusion the expiration of three months is the earliest date at which any operation should be taken into consideration, and interference is only then advisable if there is good prospect of freeing the nerve from compressing adhesions. The two strongest indications for operation are (1) signs pointing to the secondary implication of the nerve in a cicatrix, especially when these are of such a nature as to indicate local tension, fixation, or pressure; (2) the possibility of the irritation being the result of the presence of some foreign body, such as a bone spicule, or portions of a bullet mantle; in such cases the X rays will often give useful help.

With regard to the early exploration of cases of traumatic neuralgia, it may be pointed out that when this was undertaken the results were as a rule very temporary. In many cases in which the measure was resorted to, either no macroscopic evidence of injury to the nerve was discovered, or a bulbous thickening was met with of such extent as to make excision inadvisable, even if it were considered otherwise the most suitable treatment.

Even when complete section of the nerve was assured by the absence of any power of reaction to stimulation by electricity from above on the part of the muscles, operation was better not undertaken until cicatrisation had reached a certain stage. If done earlier than at the end of three weeks, the sutured spot became implicated in a hard cicatrix, and any advantage to be obtained by early interference was lost. When partial division of a trunk was determined, the same date was the most favourable one for exploration, the gap in the nerve being freshened and closed by suture. There is little doubt, however, that in some cases such injuries were recovered from spontaneously.

In view of the uniformly bad results observed in the case of the seventh nerve, I am inclined to think that the above rules might be tentatively relaxed, and the nerve primarily explored by an operation resembling that for mastoid suppuration. It is of course doubtful whether the trouble does not generally result from the vibratory concussion alone; but as this is not certain, and the operation would only have to be performed on patients already permanently deaf, it might be worth while at any rate opening the Fallopian canal with the object of relieving tension. It is not probable that in any of the cases quoted much splintering of the bone had occurred, as the wounds appeared to be of the nature of pure perforations.