Inflammation of the Arachnoid and Pia Mater.
Arachnitis.

THESE, two membranes are generally inflamed together. They are so intimately connected that each involves the other in its own troubles.
Generally this is divided into three stages:

The Irritative, characterized by wakefulness, irritable temper, repugnance to strong light, and contraction of the pupils.

The Inflammatory Stage, known by transient pains in the bead, alternating with similar ones in the bowels, increased restlessness and irritability, a quick and tense pulse, an expression of discontent on the face, the eyebrows knit and frowning, the eyelids half closed, retching and vomiting, deep sighing, and torpid bowels.

The Depressing Stage, in which the delirium is more continuous, the countenance has a look of surprise and stupor, the pupils are contracted or dilated, the white of the eyes injected and red, the pupils rolled up during ,sleep, constant sleepiness, inattention to surrounding objects, torpidity of mind, gradually increasing until complete coma closes all the senses.
The disease does not always exhibit all these symptoms, or come on in the regular way described. Sometimes the first thing noticed is a long continued paroxysm of general convulsions. Again these convulsions will come on after violent pains in the head, and are attended with screaming.