LACERATIONS AND INJURIES TO THE BRAIN SUBSTANCE.
These have been mentioned under contusion of the brain. They may be divided into those which occur with or without fracture of the cranial bones. The term contusion was first suggested by Dupuytren. The condition comprises all degrees of injury, from the most minute local disturbances to lesions involving the entire hemisphere. The milder forms show a sprinkling of punctate hemorrhages, numerous in the centre of the injured area, the surrounding tissue taking on a more or less diffuse tint, which fades out toward the periphery, discoloration being due to the imbibition of the coloring matter of the blood. In more extensive injuries clots as large as peas, or larger, are embedded at various points, each surrounded by its area of discoloration. When foreign bodies have been driven into the brain the tissue is also discolored, while various foreign materials may be met. In instances of great violence there may occur absolute rupture of brain tissue extending from cortex to ventricle.
Prognosis.
—Prognosis depends in large degree upon escape from or occurrence of infection. In infected cases the principal dangers are from blood pressure and from later edema or acute softening as well as from meningitis. Brain lacerations may heal by cicatricial repair, but usually with some perversion of function.
The possibility of cystic degeneration of large or small clots is one of great importance. (See Cysts of New Formation in Chapter XXVI, [page 264].) A blood clot within the cranium which fails to resorb is essentially a hematoma, in whose interior softening and conversion into a cyst may easily occur. These cysts make room for themselves at the expense of surrounding brain tissue, and when located in the motor area give rise to localizing symptoms as well as to epileptic convulsions. They may be often diagnosticated with certainty after an accurate history of the case and a study of the phenomena which it presents. As they grow older their walls become firmer, and it is often possible to dissect them out.
That foreign bodies may be encapsulated and remain without producing disturbance is now well known. This is particularly true of bullets. As a rule, however, though encapsulated, they produce symptoms like headache, vertigo, etc. (See [Plate XLIII].)
Symptoms.
—The general features of brain lacerations are those of contusion. So long as the disturbances are minute, even if multiple, or the foreign body small, compression symptoms are not produced, or at least in very incomplete degree. Minute diagnosis is not easily obtained. The most essential thing is to decide upon the question of operative interference. In the absence of distinctly localizing symptoms or other external markings it is not usually performed. Upon the other hand a lesion which can be localized is probably due to extravasation sufficiently large to be easily reached by opening the skull; and, unless there be other and sufficient reason to the contrary, this should be done ([Fig. 378]).
In many instances, however, contractures or paralyses of muscle groups occur later, and are followed by spastic conditions which may be permanent. More can be done in these cases by massage, by internal medication, perhaps with external counterirritation, than by distinctly surgical procedures. Tendoplastic or neuroplastic measures for their relief may also be considered. Both albuminuria and glycosuria are known to be the result of injuries herein described, as well as bulbar paralysis and disturbances of special senses. More immediate dangers after these head injuries are those of bronchopneumonia or hemorrhagic or edematous infiltration of the lower lobes of the lungs—conditions often spoken of as hypostatic pneumonia, much resembling those produced experimentally in bilateral division of the pneumogastrics. Some of them are produced by paralysis of the glottis, the result of which is incomplete closure, with aspiration of fluids and solids from the mouth, whose decomposition sets up an infection within the lungs, and is often referred to as aspiration pneumonia. Some form of pulmonary disturbance follows in perhaps one-third of the cases of the injuries above alluded to, and should be anticipated and prevented.
Fig. 378