Secondary operations for traumatic epilepsy scarcely come within the scope of these experiences. In case 73, p. 292, it is of interest to note the manner in which the cavity due to loss of brain substance was filled up. No doubt a similar vicarious arachnoid space develops in all cases in which a soft pulsating swelling fills an aperture in the bones of the skull.
Wounds of the Head not Involving the Brain
Mastoid process.—The most important wound of the cranium not already mentioned was that involving the mastoid process and the bony capsule of the ear. Wounds of the mastoid process obtained their chief interest in connection with paralysis of the seventh nerve. This nerve rarely or never escaped, and, as far as my experience went, the facial paralysis was permanent (see cases 111-114, p. 355). I think the same prognosis holds good with regard to the deafness resulting from these injuries, and it is difficult to believe, with our experience of the effect of vibration on other nerve centres and organs, that the internal ear could ever escape permanent damage.
In a number of cases the tympanum itself, or the external auditory meatus, was directly implicated in tracks; in these, also, loss of hearing was the rule.
Wounds of the pinna when produced by undeformed bullets were usually of the same slitlike nature remarked in perforations of the cartilages of the nose, and healed with equal rapidity.
Wounds of the orbit.—Injuries to the orbit were very numerous and serious in their results, both to the globe of the eye and the surrounding structures.
Anatomical lesions.—The wound tracks, with regard to the injuries produced, may be well classified according to the direction they took; thus—vertical, transverse, and oblique.
Vertical wound tracks were on the whole the least serious, but this mainly from the fact of limitation of the injury to one orbital cavity. They were usually produced by bullets passing from above downwards through the frontal region of the cranium, and were received by the patients while in the prone position.
Transverse and oblique wounds owed their greater importance to the fact that both eyes were more likely to be implicated.
Besides these tracks, which actually crossed the cavities, a number involved the bony boundaries, producing almost as severe lesions in the globe of the eye, many of the patients being rendered permanently blind. The only difference in nature of such cases was the escape of orbital structures, and this was of minor importance in the presence of the graver lesion to vision. The following is an illustrative case:—