Spinal Meningitis

SPINAL MENINGITIS. Inflammation of the membranes (meninges) surrounding the brain and spinal cord. An equivalent term is cerebro-spinal meningitis.

The meninges, like the pleura, pericardium and peritoneum, are subject to infection with a wide variety of cocci and bacilli. According to the microbic incitant, the infection is termed tuber cular, pneumococcal, streptococcal, staphylococcal, influenzal (B. pfeifferi), typhoid, etc., meningitis. The precise diagnosis is ac complished by means of the bacteriological examination of fluid (cerebro-spinal) withdrawn by lumbar puncture. The above mentioned class of bacterial infections of the meninges tends to arise sporadically; as a rule it accompanies the corresponding bacterial infection affecting other parts of the body, the lungs, middle ear, tonsils, etc.

Epidemic Form.

In sharp contrast with the sporadic varie ties of meningitis is the epidemic form, incited by the diplococcus discovered by Weichselbaum in 1887, now called meningococcus, of which many epidemic outbreaks have been recorded. The meningococcus appears not as a single, sharply defined species, but as a group in which the composing strains, while showing many properties in general, are yet distinguishable by power to ferment carbohydrates, reaction to specific agglutinating agents, etc.

Certain strains of meningococci have greater virulence for man than others and the more virulent strains show greater fixity of biological properties. During epidemics of meningitis virulent strains have the wider distribution ; while in interepidemic periods the weaker, less defined strains are more frequently encountered. A pandemic of meningitis prevailed during the first two decades of the present century. It embraced Europe, America, Asia, Africa and many islands of the seas. This pandemic was char acterized by high mortality and by those multiple clinical features which have been noted in previous severe epidemics of the disease.

A part only of the cases, usually not a large part, was attended by the visible haemorrhages in the skin and mucous membranes to which the name of spotted fever was applied in earlier times.

Usually the very severe and rapidly fatal so-called fulminating cases fell into this category.

The fatality of the epidemic outbreaks, whether in Europe, in America or in more distant countries, in the years between and 1910 did not vary greatly. In the United States the percentage figures were from 75 to 90 ; in Great Britain 7o to 8o ; in Germany 6o to 7o; in France, Italy and Belgium 75 to 8o; in Palestine 8o; in Greece 6o; in the Transvaal 75. In other words, the pandemic seems to have been little affected by locality or race. As in all previous epidemics closely observed, the mortality was influenced by the age period of the attacked ; the very young and the very old rarely survived attack. Patients between 5 and 3o years of age have the best chance of recovery.

Serum

outlook for recovery has been greatly modified by the discovery and use of the antimenin gococcic serum since 1904. Attempts to produce a curative serum were carried out simultaneously in Germany by Jochmann and Wassermann, and in America by•Flexner. The former failed per haps because the manner of use was wrong: the serum was injected chiefly subcutaneously. The latter succeeded, because repeated injections were made directly into the inflamed meninges by means of lumbar puncture. Flexner's method was based on an experi mental study in which the meninges of monkeys were infected with the meningococcus, and the treatment was applied by lumbar puncture. The serum-treated monkeys survived, while the un treated and those treated by subcutaneous injections of the serum succumbed.

This result agrees with what is known of the anatomical physiological conditions affecting the passage of chemical sub stances from the blood into the cerebro-spinal fluid. Such passage, even when the membranes are inflamed, takes place to a very small extent or not at all.