The pus rapidly spreads over the surface of the cerebrum and over the base of the brain, along the sheaths of the emerging cranial nerves, and down the spinal canal. Associated with vascular dilatation there is extensive leucocyte extravasation into the perivascular spaces, the course of the line of the attack being mapped out by white and yellow lines and areas of exudation. Insomuch, also, as the meningeal vessels are in direct continuity with those of the cortex itself, it follows that a well-developed case of meningitis implies a corresponding degree of cerebritis, with red or white softening of the brain substance according to the degree of hæmorrhagic extravasation.
Symptomatology.
Meningitis is generally sudden in onset and ushered in by a rigor, frequently of a most intense character. Headache is always a marked feature, commonly diffuse, but sometimes localized to the region primarily and mainly affected. The headache is intense and exacerbations are marked, the patient crying out in his agony. There is great mental irritability and all attempts at clinical examination are strenuously resisted.
After the initial rigor the temperature remains high, with occasional remissions during the early hours of the morning. Vomiting may be frequent and violent, but, according to my observations, this has not been a conspicuous feature.
The pulse-rate is increased, whilst, in the early stages, the volume is full and the tension high. The skin is burning hot and dry, except during the post-rigor periods when sweating predominates.
The face is flushed, often turgid, and the eyes are bright. General restlessness is a marked feature.
The more localizing features may be arranged in three groups: intellectual, motor, and sensory.
Intellectual symptoms.
The condition of the patient is one of great restlessness, increasing sometimes to actual violence and mania. Attendants are usually required to restrain his movements, and, tossing about in bed, crying out in his pain, muttering and wandering in his delirium, he offers a typical clinical picture of cerebral irritation.