The principles and practice of modern surgery

by Roswell Park

The tetanus bacillus manifests other peculiar properties, for some of which it is most difficult to account. Upon susceptible animals it is violently infectious, but is rarely found at any distance from the tissues in which it has first lodged. In laboratory investigations the period of incubation is seldom longer than forty-eight hours. Another peculiarity of the organism is that it generates certain poisons of active properties which may be separated from pure cultures, by whose injection the peculiar spasms of the disease itself may be reproduced. These have been isolated, especially by Brieger, who has given to them the names of tetanin, tetanotoxin, spasmotoxin, etc. It has been estimated that about ¹⁄₃₀₀ Gm. of the pure toxin of tetanus would be a fatal dose for a man. This toxin seems to have a specific affinity for the ganglion cells of the anterior horn of the spinal cord, with which it unites with great force. Herein lies the secret of its disturbing power.

It is peculiar that some time may elapse after its injection before the appearance of the first symptoms. Diphtheria toxins appear to be prompt in their action, and thus display quite opposite characteristics. Experiment would seem to show, moreover, that the tetanus toxins do not reach the cord through the blood stream, but appear to slowly pass along the axis cylinders. Sensory nerves do not transport the toxins to the cord. The toxin enters the nerve termination, first of all, at the site of the infection, where it is most concentrated, which will explain why the spasms most frequently begin in the vicinity of the infection, or are the most marked there. Most of the toxin is taken up by the blood and lymph and distributed all over the body, and then passing along the motor fibers it enters the cord and leads to general convulsion. When the toxin is injected directly into the cord the symptoms begin at once. Therefore, for protective purposes, much may be expected from the administration of the antitoxin in cases of suspicious injury or those where experiment has shown there is reason to fear the development of tetanus. There does not appear to be on record a single instance in which a person who had been given antitoxin soon after receiving such a wound has developed tetanus, nor does the antitoxin by itself seem to have done any harm. Obviously, then, the earlier antitoxin is used in the case the better. It may be recalled that there are no diagnostic symptoms of tetanus until the first spasm develops, usually after the expiration of from five to twelve days. By this time the nerve cells are thoroughly saturated with the poison and considerable time may elapse before the antitoxin can reach these cells by a more indirect route.

Tetanus Neonatorum.

—Tetanus neonatorum, or tetanus of the newborn, a condition already alluded to, is a remarkably fatal affection, very prevalent among the negro race, especially in hot climates. It nowise differs from traumatic tetanus, but is such in effect, since the infection in these instances always follows the division of the umbilical cord, which is usually effected with dirty scissors in the hands of a dirty midwife, while the thread with which the cord is tied is itself a possible source of infection, as well as the rags which are used to cover the umbilicus in the first dressing. It is generally fatal, because of the weakness and lack of resistance of these little patients. It occurs usually within a week after birth, if at all.

Tetanus Cephalicus.

—Tetanus cephalicus, called also tetanus hydrophobicus and head tetanus, is only a peculiar manifestation of this same affection, confined mainly to the head and usually following injuries to this region. The muscle spasms are mostly confined to the facial, pharyngeal, and cervical muscles, sometimes extending to the abdominal. These manifestations may be reproduced in animals by inoculating them on the head rather than upon the extremities. It is the least fatal form of the disease.

Symptoms.

—There is always a period of incubation, usually three or four days, occasionally a week in length, but rarely longer.

It is generally held that the longer the period of incubation the more hopeful the prognosis. While for the great part the disease assumes an acute type, a chronic tetanus is described and occasionally seen. The first warning of the disease usually comes as more or less stiffness of the cervical and maxillary muscles, which is likely to be referred to by the patient as a “sore throat,” because of the consequent difficulty in deglutition. A complaint to this effect should be regarded as a warning, especially if on inspection no visible reason for it can be detected in the pharynx. This complaint is usually made in the morning after an ordinary night’s rest. This muscle stiffness will be followed by increasing tonic spasm in the muscles of the jaw, making it difficult to open the mouth, while the head and neck gradually become stiffened and fixed by spasm of the cervical muscles. These muscles may now be felt more or less rigidly contracted, as if by voluntary effort, and the condition, which is at first not painful, becomes after some hours a source of discomfort, perhaps of actual pain, to the patient. If the disease pursues the usual course, the other muscles of the body become gradually affected, usually in the order of their proximity, but not necessarily so. The abdominal muscles are firm and board-like, and the dorsal muscles more or less contracted, sometimes to an extent which causes arching of the spine. Should the original wound or port of entry for infectious germs have been in the hand or foot, the muscles of this limb become contracted, more or less rigidly, holding it in a position which is not easily changed, even by efforts of the attendant. Sensation is also often more or less perverted. In this condition of tonic rigidity the muscles remain, to relax usually only with death.

The most characteristic features of the disease, however, are the peculiar clonic exacerbations, which convert spastic rigidity into violent and convulsive muscle activity, so that the limbs and even the frame of the patient are more or less contorted, the muscle exertion being sometimes painful to witness. Notable effects are thus produced; the mouth is peculiarly puckered, and its corners drawn upward and backward by the risorius muscles, giving to the face that peculiar expression known as the “sardonic grin.” When the abdominal and flexor muscles of the thighs are involved, and the body is more or less curved forward, this condition is known as emprosthotonos; when the muscles of the back especially are involved, with the extensor muscles of the thighs, as opisthotonos; and when the body is bent to one side or to the other it is called pleurosthotonos. It is said that opisthotonic convulsions occur to such an extent in some instances that the heels touch the head. At all events, the patient’s body is frequently raised from the bed, so that he rests upon the head and feet.