Louis Bathe Rawling

“ Injury to the brain must always be regarded as by far the most important of the many complications associated with fracture of the skull. A fracture is not necessarily accompanied by brain-injury, and laceration of the brain may exist without a fracture. There can, however, be no question that the more severe cases of head-injury are almost invariably associated with some degree of brain-injury—varying from contusion to extensive laceration, cortical or central. ”

“ It is therefore only necessary to enter into those cases of fractured base which are associated with concussion, irritation, and compression of the brain—in other words, the average case of fracture of the base of the skull.
The surgeon must always be guided by the general condition of the patient—the blood-pressure, character of pulse, state of respiration, depth of unconsciousness, &c.—but, in my opinion, the temperature chart affords perhaps the most valuable basis on which rules can be formulated guiding the surgeon in his general line of treatment. ”

“ Flaps are usually to be preferred if the surgeon desires to have the widest possible view of the brain surface. In the formation of the flap, advantage should be taken of the vessels that minister to its vitality. Thus, in the lateral region of the head, the base lies below, the middle meningeal artery supplying the flap. Under special circumstances, the blood-supply may be disregarded; the flap never sloughs, so far as my experience goes.
Sewing up the dura mater. Considerable difficulty may be experienced in sewing up the dura—by reason of the bulging of the brain. ”

“ A compression force—whether foreign body, blood extravasation, abscess or tumour—must act on the brain substance or on the fluid constituents of the skull. The brain, however, is itself incompressible. It may be squeezed like a sponge, but its actual structure is unalterable. Consequently, the compressing force exercises its main influence on the fluid contents, driving out the cerebro-spinal fluid, depleting the cerebral veins and emptying the arterioles, producing in other words a state of brain anæmia. ”

“ I have operated on over a dozen cases of chronic cephalalgia, and I have found in nearly every case definite pathological lesions—depression of internal table, thickening of the meninges, subdural cysts and subdural hæmatomata. The mere removal of a disk of bone may relieve the symptoms by reducing the local pressure or by removing a source of meningeal irritation, but such treatment seldom brings about permanent relief. The dura mater should be opened in nearly every case, the frequent discovery of a subdural complication—cyst or hæmatoma—showing that such a course is necessary. ”

“ Phelps pointed out that the lesion must be an extensive one if the symptoms included under the term sensory aphasia (word-blindness, word-deafness) are to be evolved. No localized injury to any small area suffices, and the cortex must be deeply involved. Lacerations of the brain are usually of so gross a nature that further differentiation is seldom to be obtained. Here it might be noted that the cortical centres responsible for speech and its accessories, word-seeing, word-writing, and possibly word-hearing, are all situated on the left side in normal right-handed individuals. ”

“ In the great majority of cases the blow was applied to the temporal region, the patient was rendered unconscious, bleeding freely from the ear, nose, and mouth, and remained under treatment for some considerable time. From these facts it may be assumed that the patient suffered from a fracture of the base of the skull—anterior or middle fossa, or both fossæ. Evidence has already been brought forward to show (1) that the majority of fractures involving both anterior and middle fossæ traverse the body of the sphenoid, and (2) that the cavernous sinus is very susceptible to injury. ”

“ Middle meningeal hæmorrhage, uncomplicated by brain injury, is of infrequent occurrence, the associated injuries to bone and brain confusing the diagnosis. Moreover, the special pressure effects are dependent not only on the absence of serious brain lesion, but also on the non-existence of a safety-valve, such, for instance, as is afforded by a comminuted fracture of the bones entering into the formation of the temporal fossa, or of the roof of the middle and external ears. ”

“ In the vault of the skull, bone developes between the dura mater and its cutaneous cap, but the skin and dura mater remain in contact along the various sutures even for a year or more after birth. This relation persists longest in the region of the anterior fontanelle and the neighbourhood of the inion. Should the skin be imperfectly separated, or a portion remain persistently adherent to the dura mater, it would act precisely as a tumour germ and give rise to a dermoid. Such a tumour may retain its original attachment to the dura mater, and its pedicle become surrounded by bone ”

“ As Sir William Macewen [58] pointed out, ‘an uncomplicated brain abscess may be regarded as the most hopeful of all cerebral affections.’ In fatal cases, death results from general meningeal infection or from the bursting of the abscess into the lateral ventricles.
In meningitis the prognosis is bad, more especially when the process is widespread. Early exposure of the affected region and the supply of adequate drainage offer the only hope of recovery. This, even under the most favourable circumstances, is a desperate remedy. ”

“ Palpation may reveal the nature of the tumour, whether fluid or solid.
Exploration of the brain should only be undertaken in the light of a reasonably certain diagnosis, and every precaution must be taken [234] to avoid needless damage to the cerebral substance. The exploration should invariably be preceded by incision with the brain-knife or scalpel, introduced in such a manner as to avoid injury to all visible vessels and directed at right angles to the surface of the brain, so as to cause the least possible damage to the corona radiata, &c. ”

“ When the bullet is ‘spent’, the osseous injury at the point of impact is usually of a more extensive character than when the bullet possesses a higher degree of velocity. When fired at close quarters the damage incurred from the impact of the bullet is increased by the force of the forwardly driven air and gas. The skull suffers proportionately, the scalp being severely lacerated, burnt, and circumferentially ingrained with powder, the bone extensively comminuted, and the brain severely lacerated. ”

“ Fissured fractures in the very young possess another point of interest in that the cleft often tends to increase, this being notably the case when the fracture is associated with injury to underlying dura and brain. The local and general increase of intracranial pressure not only widens the gap, but also leads to thinning and eversion of the margins of the deficiency with possible herniation of brain-matter—traumatic cephalocele. ”

“ So long, however, as surgeons will persist in burrowing into the brain substance for a supposed subcortical tumour, so long will the mortality remain high. The great secret in operating on a brain tumour lies in knowing when to terminate the attempt at removal of the tumour and when to rest content with a pure ‘decompression’.
It is obvious, therefore, that cortical tumours—more especially such as give rise to early localizing symptoms, e.g. Rolandic tumours—offer a better prognosis than when the surgeon has to deal with subcortical, central, and basal tumour formation. ”

“ If, however, the tumour be subcortical in position, its position and boundaries may be estimated by electrical stimulation, palpation and exploration.
Electrical stimulation will evidence whether the area exposed corresponds to the symptoms evinced by the patient. With respect to the actual technique, one pole is placed on the patient’s extremity—it matters not which, though preferably on the homo-lateral side—the other over the exposed brain. The current should be just strong enough to contract exposed muscle—some of the fibres of the temporal muscle are generally available for the purpose. ”

“ On the other hand, it cannot be urged too forcibly that hasty and ill-determined explorations usually terminate in failure. Even under the most promising circumstances it by no means follows that the bullet will be found at the site of counter-trephining, as it may have rebounded to some more distant region of the brain, necessitating an operation conducted over a totally different region. Thus, in a case recently under my care, the bullet entered at the right temporal region, penetrated the brain and produced on the left side of the head a well-defined wound of attempted exit. ”

“ Every care must be taken to avoid unnecessary damage of the brain-matter.
When the tumour is situated in the cerebello-pontine angle, a somewhat favourite site for tumour formation, ‘lateral displacement’ of the cerebellum towards the middle line will aid considerably in the exposure. A flat retractor, bent to a suitable curve, is introduced between the dura and the cerebellum, and the brain-matter gently but firmly retracted towards the middle line. As the brain yields to the pressure the tip of the retractor is insinuated towards the posterior surface of the petrous bone. ”

“ When the patient is fully under the anæsthetic, the final cleansing of the scalp is carried out and the operative field cut off from all possible sources of infection. In the States, in Cushing’s clinic, the anæsthetist is completely covered with a large sterilized sheet, which is fastened to the head of the patient. In this country we prefer that our anæsthetist should have full knowledge of the progress of the operation, and I think that the advantages are with us. In any case, the whole head is enveloped in gauze, two or three layers thick and about 18 inches square. ”

“ The more general results are headache, vomiting, optic neuritis and atrophy, slow pulse-rate, somnolence, and coma. The temperature is variable, more commonly rising during the more acute stages of the disease, and falling to normal or subnormal during the quiescent periods.
Localizing features are to be found in squints, inequality of pupils, retraction of the head and neck, dyspnœa, and dysphagia, whilst compression of the cortical motor centres is evidenced by twitchings, convulsions, and spasticity of the limbs. General convulsions are by no means uncommon. ”

“ Whether dependent on injury or not, the symptoms associated with sarcoma of the skull vary according to whether the tumour is extrinsic or intrinsic—whether, for instance, the growth develops in the inward direction and presses on the brain, or grows from the pericranium and is directed externally. Intrinsic tumours, with the exception of some local pain, œdema of tissues, and dilatation of superficial veins, give rise to symptoms closely resembling those observed in intracranial tumour formation. ”

“ One word of warning—the temperature must be taken every half-hour, and active surgical measures adopted so soon as the rising temperature, slowing high-tension pulse, and deepening unconsciousness point to advancing compression.
There is undoubtedly a growing tendency amongst those who have carefully studied the effects of trauma on the skull and brain to carry out exploratory and decompression operations at an early period, even in cases which present no symptoms of special localizing significance. ”

“ To this course, however, there are two great objections: (1) the exposed cortex most commonly includes the motor area, herniation of which will lead to disastrous effects on the extremities of the contra-lateral side—spasticity, paralysis, aphasia, &c.; and (2) the herniation of brain-matter including, or closely related to, an irremovable tumour tends to lead to œdema of the brain tissues and softening of and hæmorrhage into the growth, with subsequent rapid development of the outwardly protruded mass. ”

“ Here, as the result of injury to scalp, bone, dura, and brain, the cerebral substance bulges through a deficiency in the vault and presents on the surface, uncovered by integument. Hernia cerebri can develop under non-infective conditions, the congested state of the bruised or lacerated brain bringing about that degree of intracranial tension which can only be relieved by the outward projection of the brain. Still it must be accepted that Hernia cerebri almost invariably implies some bacterial infection. ”

“ Till, therefore, more evidence comes to hand with respect to heat-regulation in general, one cannot go beyond the broad statement that, in severe head-injuries, definite temperature changes occur, that the changes are independent of any special lesion of bone or brain, that they are generally associated with some brain-injury, and that they are probably due to the influence exerted by the lesion on the heat-regulating centres in the region of the pons and bulb. ”

“ Previous to successful evacuation, the brain immediately surrounding the abscess cavity is compressed and anæmic. As soon as drainage is supplied, it swells out like a sponge, more or less obliterating the cavity. The closure of a cavity by means of the formation of granulation tissue probably never occurs, and, if the falling together of the surrounding brain is insufficient to obliterate the cavity, final closure is completed by the in-dragging of the overlying tissues—scalp, membranes, and brain becoming intimately fused together. ”

“ Returning once more to the vascular effects of a localized compression, it is obvious that whilst the compressing force is producing a surrounding anæmia—depleted veins and arterioles—yet that the neighbouring but more distant brain is venously engorged—from venous retardation. Insomuch, moreover, as the venous tension and cerebro-spinal pressure are equal, it is obvious that, as the result of venous engorgement, there is some surrounding serous transudation into the perivascular, pia-arachnoid, and cerebral regions. ”

“ When associated with symptoms of brain-compression, exploration is almost always advisable, the scalp-tourniquet being applied and the injured region exposed by a suitable scalp-flap. Depressed bone is elevated, or the trephine applied so as to fully expose the underlying dura mater. A bulging, non-pulsatile, and plum-coloured membrane points to the existence of a subdural hæmatoma. The membrane is then incised and the clot evacuated. Whenever possible the dura mater should be sewn up and the scalp-flap replaced without drainage. ”