The severe and rapid sloughing of the nates sometimes seen in rapidly-fatal cases is stated by Joffroy to be most frequently connected with a lesion of the occipital lobes.52
52 Arch. gén., Jan., 1876.
It is plain, from what has been said about the symptoms of the different kinds of lesion, that a distinction may be often very difficult, and at times impossible; and in this connection all observers are agreed, the apoplectiform shock, the hemiplegia, and the slighter attacks being common to two or three lesions. The diagnosis can be made, if at all, only by the consideration of more or less secondary symptoms and the careful weighing of the various probabilities against each other. Most of the statements of differences of symptoms are only relatively true.
A glance at the nature of the pathological processes involved may serve to systematize our observations.
Hemorrhage is a sudden accident, with a severity increasing as the amount of effusion increases. It has been prepared for by arterial disease, but this disease is one which may have no previous symptoms. It is at first an irritative lesion.
Embolism is a sudden attack which may be as severe at first as even a few minutes afterward. It is also prepared for by disease of other organs, which may or may not have symptoms according to the origin of the embolus. As embolism affects especially those regions where the motor centres are spread out, while hemorrhage attacks more frequently the conductors in their locality of concentration, the paralyses arising from the former affection may be more narrowly limited.
Thrombosis is a gradual affection, which may, however, manifest itself suddenly, from the obstruction reaching a certain point and suddenly cutting off the supply of blood. This also depends on previous disease which has more or less definite symptoms.
The severity of the attack is not conclusive, though the completely developed apoplectic attack is more frequent with hemorrhage. Rapidly increasing severity, especially if there have been prodromata, is in favor of hemorrhage. Convulsions, early rigidity, and conjugate deviation of the eyes of the spastic form, especially if afterward becoming paralytic, are strongly in favor of hemorrhage, and the latter possibly conclusive. Hughlings-Jackson states that he cannot call to mind a single case of hemiplegia from clot in a young person in which there were not convulsions.
Sudden paralysis without cerebral prodromata, unconsciousness, or pain can hardly be anything else than embolism; but, unfortunately for diagnosis, the initial paralysis from the embolus may be slight, and afterward added to by the secondary thrombus, so as to put on the appearance of more gradual approach.
Aphasia, and especially aphasia associated with but little or no paralysis, is very much more frequent with embolism than with hemorrhage.