The mind is generally clear in the early stage; afterward there may be delirium, especially along with cerebral complication.
MORBID ANATOMY.—It is rarely that the pia mater is the only tissue involved in the inflammation. Frequently the inner surface of the dura is the seat of a fine injection, with delicate false membranes, and the cord itself—at least its exterior portions—probably always participates more or less in the congestion. The pia is reddened and thickened, the surface showing small bloody extravasations, and the space between its two layers is the seat of a fibro-purulent deposit. The spinal fluid is turbid and flocculent. The seat and extent of the morbid appearances vary in different cases; they are always more abundant in the posterior than the anterior part of the cord, and may be confined to a limited space or extend throughout its whole length. It is remarkable that the region of the medulla oblongata is generally free or only slightly affected; but since bulbar symptoms are often prominent in grave cases, Leyden6 accounts for it by supposing that the exudation is washed away by the constant movement of the cerebro-spinal fluid. If the cord be involved in the inflammation, it is softened and injected, the nerve-sheaths are destroyed, and the axis-cylinders swollen in places. The nerve-roots show hyperæmia, infiltration of the interstitial tissue with round cells, and destruction of the nerve-sheaths.
6 Klinik der Rückenmarks-krankheiten, von E. Leyden, Berlin, 1874, vol. i. p. 407.
DIAGNOSIS.—Spinal meningitis is easily recognized in most cases by its sudden onset and the severity of its symptoms. The distinguishing symptoms are sudden and acute pain in the back, extending around the body and into the limbs, which is increased by every movement of the trunk, rigidity of the back, hyperæsthesia of the skin, retraction of the head, with difficulty of breathing and of swallowing. The diseases from which it must be distinguished are muscular rheumatism (so called), tetanus, and myelitis. In rheumatism of the dorsal muscles the pain is confined to the back, does not extend to the limbs, and is only excited by movement. The fever is moderate or absent; there are no symptoms of spinal complication, such as cutaneous hyperæsthesia, retraction of the head, paresis of the limbs, etc.; and the result is uniformly favorable. Tetanus is almost always due to some well-marked traumatic cause; the muscles of the jaw are usually first implicated (trismus); and the attacks of general muscular spasm are easily excited by peripheral irritation. Myelitis can be distinguished by the absence of pain in the limbs and by paraplegia, but it must be borne in mind that myelitis and spinal meningitis may coexist.
PROGNOSIS.—Acute spinal meningitis is always a grave disease, hence a guarded opinion should be given even in apparently favorable cases. General mildness of the symptoms, with no indication of extension to the medulla oblongata, would afford ground for encouragement. The unfavorable symptoms are those showing compression or inflammation of the cord, such as paresis, paralysis, twitching of the limbs, muscular contractions, cutaneous anæsthesia, etc. The extension of the disease to the medulla, as shown by difficulty of swallowing, speaking, or breathing, is almost necessarily fatal.
TREATMENT.—During the first stage of the disease an effort should be made to reduce the hyperæmia of the membranes by the local abstraction of blood. This is best effected by cupping along each side of the spine and by the application of leeches to the anus; the bleeding should be promoted by poultices. Free purging is likely to be of service, and is best obtained by means of ten grains each of calomel and jalap (for an adult), followed by saline laxatives. Counter-irritation to the back may be induced by the application of blisters or by painting the skin with a strong tincture of iodine (one or two drachms of iodine to an ounce of sulphuric ether). After the effusion of lymph and pus, as shown by symptoms of compression of the nerve-roots and cord, absorbents should be tried, of which the iodide of potassium, in doses of five to ten grains, four times daily, is most likely to be of benefit. Pain must be relieved by opium or morphia and chloral hydrate. The latter, either alone or combined with hyoscyamus and bromide of potassium, will be useful to allay spasmodic twitching, opisthotonos, or muscular contraction. The patient should be enjoined to lie on each side alternately, or on the face if possible, in order to equalize the hyperæmia of the membranes and cord. Liquid nourishment must be freely administered, such as milk, broths, gruel, etc., together with wine and other stimulants in case of exhaustion and threatening of collapse. During convalescence the patient should be carefully protected against cold and fatigue, and the strength must be supported by quinine and iron with suitable diet.
Chronic Spinal Meningitis.
SYNONYMS.—Chronic inflammation of the pia mater of the spinal cord, Chronic spinal leptomeningitis.
Chronic spinal meningitis may follow the acute form, or it may arise from chronic disease of the vertebræ or of the cord, especially myelitis and sclerosis. It is most apt to accompany sclerosis of the posterior columns, and it is often difficult to say in any particular case whether the meningeal affection preceded or followed that of the cord. Probably some cases of chronic myelitis, especially of the disseminated form, owe their origin to chronic meningitis.7 It has been thought to follow blows on the back, and also to arise from general concussion without traumatism, and has been considered as a frequent result of accidents from railroad collisions, etc. This view has been disputed by Herbert W. Page,8 who says: “Of the exceeding rarity of spinal meningitis as an immediate result of localized injury to the vertebral column we are well assured.... And we know of no one case, either in our own experience or in the experience of others, in which meningeal inflammation has been indisputably caused by injury to some part of the body remote from the vertebral column.” Chronic alcoholism and syphilis, especially the latter, predispose to the disease. In many cases no adequate cause can be assigned.
7 Leyden, op. cit., vol. i. p. 442.