LARYNGISMUS smmumus (child-crowing, spasm of the glottis, internal con vulsion) is very common in England. The complaint is a form of convul sive seizure which is limited to the muscles of respiration. Sometimes it affects exclusively the muscles of the glottis ; in other cases it may impli cate also the diaphragm and other muscles concerned in breathing. The disorder must not be confounded with laryngitis stridulosa, in which there is inflammation of the glottis with spasm superadded. Laryngismus, as it affects the vocal cords, is a pure spasm, arising, as other spasmodic attacks are so apt to do in the child, from reflex irritation.
• Causation.—The complaint may be met with under two different con ditions : In new-born infants. in whom no other deviation froth health can be observed, and in rickety children between the of six or eight months and two years.
The spasm appears to be predisposed to by foul air and hot, ill-venti lated rooms. It is a remarkable and suggestive fact that the disorder is essentially a winter complaint, being prevalent when windows and doors are kept closed for the sake of warmth. It is rarely seen in summer, when every window is open to admit the air. Still, the derangement may occur without our being able to attribute it to any impurity in the air. In these cases it may be due to some special irritability of the reflex centres peculiar to the individual infant.
Few writers now hold the opinion that laryngismus is the result of pres sure upon the vagus or its branches by an enlarged thymus gland. Were this so, cases of laryngeal spasm would surely be much more numerous than they actually are. Moreover, M. Herard has reported that in six children who had died from this complaint, the size of the gland presented such striking variations that it was impossible to connect it with the pro duction of the. laryngismus from which they had suffered. It is equally improbable that pressure of any other kind set up on the pneumogastric or its recurrent branch can produce the disorder. The effects of such pressure in the case of enlarged bronchial glands are well known. Hoarseness of the voice and violent paroxysmal cough are early symptoms, and if spasm is induced it occurs, usually, at a late period, when the existence of the dis ease is beyond a doubt. Spasm occurring alone without warning, and as suddenly subsiding without other symptoms being noticed, is not a char acteristic of enlarged bronchial glands.
The association of laryngismus with rickets is indisputable. It was first pointed out by Elsasser, and was dwelt upon by Sir William Jenner in his lectures on rickets in 1860, and more lately by Drs. Gee and Henoch. For many years I have paid attention to this matter, and can call to mind but few cases of laryngismus occurring after the age of six months in which the child was not rickety in some degree. It is important to remember, in in vestigating this point, that the patients do not always show a marked degree of rickets. They may do so ; but as often, perhaps, as not, the child is fat, although pale and flabby—a big child, although a weak one. This connec tion with rickets—a disease in which the irritability of the nervous centres is known to be exalted—is a strong argument in favour of the reflex origin of the spasm. It also serves to explain the cases where many children of a family have suffered in turn from the complaint ; for when a first child is rickety the others who are brought up under similar conditions usually be come so too. Moreover, the tendency to laryngismus is often combined
with a tendency to tonic and clonic spasm. In the same family one child may suffer from spasm of the glottis, another from general convulsions ; or in the same child attacks of laryngismus may alternate with general eclamptic seizures, or may even be complicated by them. That the latter disturbance is often a pure neurosis is universally conceded ; it seems, therefore, needlessly creating a difficulty to search for a different explana tion for the former. Still, many other conditions have been said to be capable of causing the complaint. Various lesions of structure connected with the cerebrospinal system have been discovered in children dying in a spasm, and in all of these cases a connection has been supposed to exist between the symptoms observed during life and the morbid appearances found in the dissecting-room. Thus the laryngeal trouble has been referred to chronic hydrocephalus, to exostosis in the skull cavity, or to actual pressure of pillow upon a softened occiprt. It seems highly probable that in all these cases the special pathological condition has been a pure coincidence, or at any rate has had only an indirect influence in inducing the nervous commotion. That no evident tissue change is needed to excite a perfect and even fatal spasm is proved by the numerous cases on record in which, after death in laryngismus from apncea, no lesion of the cerebro spinal system or of the glottis could be detected. It is equally certain that under ordinary circumstances intracranial inflammations and effusions do not produce spasm of the glottis, and there is no evidence that pres sure upon the substance of the brain or spinal cord will have any such effect.• The exciting cause of the seizure is usually some peripheral irritant, as in the case of reflex convulsions. There may be disorder of the digestion or other irritation of the stomach or bowels, or a swollen, tense gum. The child may have been exposed to a sudden chill, and according to Henoch cold and catarrh of the air-passages are the most frequent source of this form of reflex irritation. Li the few cases which have come under my notice of laryngismus attacking a child some time after birth where symptoms of rickets were completely absent, the spasms appeared to be due to slight laryngeal catarrh occurring in a nervous, sensitive child. I was asked some time ago to see a healthy baby, seven months old, who had cut two teeth and was cutting his upper incisors. The little boy was peculiarly preco cious, and had the bright, intelligent face of one twice his age. There was no enlargement of the ends of the bones or other sign of rickets. The child was brought up at the breast, and his general health was good al though his bowels were habitually costive. Some days before my visit the child had caught cold and had begun to cough. His voice also had been husky. Since that time he had alarmed his parents by occasionally mak ing a noise in his throat "like the crowing of a cock." He did not suffer from clyspncea, nor was there any lividity of the face. The sound was evidently clue to a slight spasm of the larynx, which passed off almost im mediately and seemed to cause little inconvenience to the infant himself.