Inflammation of the meninges of the brain and the cord may arise from a multiplicity of causes, and as a primary disorder or secondary to other disease, general or local. It may result also from traumatism. It has been observed in connection with a number of acute infectious processes, and it has developed through extension of adjacent disease, as from the nose and the ear. It is occasionally found as a terminal process in fatal cases of nephritis, arteriosclerosis, heart disease and gout.
The micro-organisms most commonly related etiologically with cerebrospinal meningitis are the meningococcus, the pneumococcus, the tubercle bacillus and the streptococcus, although others also are found at times. The first named is now generally considered responsible for the epidemic variety of the disease, so-called cerebrospinal fever. The differentiation clinically of these several forms depends essentially, when it can be made, upon the attendant circumstances, the knowledge of epidemic