De epilepsia disputatio

The affected part.

XVII.
Avicenna believes the affected part to be the anterior ventricles of the brain: for he sees that in this affection the sentient faculty is especially harmed. Others believe it to be the posterior, because of the symptom that first appears, because of the fall, and the depraved motion. We, with Hippocrates and Galen, situate epilepsy in the whole brain, and this can also be proved by reason.

XVIII.
For in it, both the principal and the motor and sensible faculties are harmed, the author and principle of which, or as it were the common workshop, is the brain.

XIX.
For when that troublesome matter stimulates the brain, the faculty, both moving and sensing, first perturbed and as if stunned, meanwhile deserts its other functions, and so that it may expel the noxious cause, it gathers itself inward. Hence the senses (and because of this, reasoning also) and the motion of the whole body are lost: hence the patient falls down and cannot stand.

XX.
However, we do not deny that one certain part of the brain is affected first, which the inimical matter stimulates first, whether that part be the body of the brain, or the walls of the ventricles, or the membranes which the Greeks call meningas meninges.

Causes.

XXI.
The internal and proximate cause of epilepsy, and that which brings it about by act, is for the most part a vapor or flatus, either generated in the brain itself or carried from elsewhere, which is troublesome to the brain not by obstruction, not by weight, but by its malignant and either occult and poisoned quality, or it pricks, stimulates, and irritates the brain with some manifest and sharp causticity to that expulsive motion, for as long as that matter is either transmitted elsewhere or dissipated and ceases to be troublesome.

XXII.
In the same way, even a thin humor, whether it be ichor a thin, watery discharge,