A system of practical medicine. By American authors. Vol. 3

by Unknown

Paræsthesia.

Closely connected with hyperæsthesia of the larynx is a form of sensory delusion consisting of the impression that some foreign substance is lodged in the organ or that there is some alteration an the structure of the parts. This is known as paræsthesia.

ETIOLOGY.—The first variety of sensory delusion depends on a primary injury to the parts. A bone or pin or some other foreign body, perhaps having lodged in the parts for a short time, has left a persistent impression upon the mucous surfaces. It is possible that in some instances there may have been no foreign body in the parts, as we have in many cases only the statement of the patient. Local inflammations, small in extent, may possibly have left the parts in a morbidly sensitive condition justifying on the part of the subject the hypothesis of a foreign body.

The second variety of paræsthesia is the expression of some disturbance in a distant part. It is usually hysterical in its character or a variety of hysteria associated with neurasthenia. It belongs to the same class of phenomena as the sensory delusions in other parts of the body. The globus hystericus is one of its forms. Thaon⁵ says that hysteria may give rise to neuralgia as well as to other forms of hyperæsthesia of the larynx. It also, according to this author, produces that form of paræsthesia in which there is a sense of a bone or pin or some foreign substance in the larynx. The general condition of asthenia, and especially of neurasthenia, may be assigned as a predisposing cause. The local injury in the one case and the general hyperæsthetic condition in the other, with some determining fact, such as the mental impression or an apprehension of trouble in the larynx, constitute the exciting causes.

⁵ Proceedings of the International Congress of Laryngology.

SYMPTOMS.—It usually comes on after an injury or as a result of the presence of a mechanical obstruction or irritation, the presence of a bone or pin being frequently invoked as an explanation of the feeling. In a few cases the sensation is suggestive of an alteration of the structure of the parts. Patients are inclined to think that they have a tumor or that there is some deformity. In the first class of cases there is a sense of pricking or of scratching in the larynx. This is not constant in locality or in intensity. There will be times, occasionally days, in which the sensation may be entirely absent, after which it returns with great severity, the patient insisting that the cause of the trouble has simply changed its location—in other words, that there is a migratory body in the throat. That form of paræsthesia in which the sensation is that of a tumor or malformation is also irregular in the mode of its manifestation or kind of disturbance. Like the other forms, it comes and goes, changes its location, and undergoes modification in its character. It may be associated with neuralgia.

DIAGNOSIS.—Hyperæsthesia and paræsthesia are recognized by the symptoms already described and by the aid of the laryngoscope. The mirror reveals the fact that the parts are normal in structure and that there is no foreign body present. The mucous membrane may be hyperæmic or anæmic, but is not the seat of any active inflammation. The excessive sensibility and pain of the larynx in ulceration of the parts will be excluded from this group of troubles by the revelation of the laryngeal mirror. Cases of pain or perverted sensation dependent upon the disorders of the nerve-centres usually involve the whole range of functions supplied by the pneumogastrics, and will generally be recognized by this fact. Such cases can hardly be called local, and do not belong to the group of affections embraced in this article.

PROGNOSIS.—The prognosis of simple paræsthesia of the larynx is not grave. Though it may exist for a long time, it, so far as we know, does not terminate in death. While it sometimes results in recovery without treatment, it in a large proportion of cases yields only to both local and general treatment. Its duration is uncertain. Paræsthesia coming on after the presence of a foreign body in the organ may last many months and then gradually disappear. This result will be largely aided by the moral support which is gained if we can convince the patient that the sensation is entirely a delusion.

TREATMENT.—For the purpose of meeting local indications in hyperæsthesia we may apply with a brush or by the means of the atomizer a solution of morphine and alum of the strength of 15 centigrammes of morphine and 2 grammes of alum to 50 grammes of water, or to this may be added 20 centigrammes of carbolic acid and 10 grammes of glycerin. Of this solution an application may be made each day with the hand-atomizer. The hand-atomizer is preferable to the steam-atomizer, for the reason that we know in the use of the former the strength of the solution. In the use of the steam-atomizer the medicated solution is diluted with the water of the steam, and we are ignorant as to the strength of the application. The method of application by the use of the atomizer is to be preferred to the brush or sponge probang, for the reason that we produce by it no mechanical irritation of the parts. The brush or sponge can hardly be used without giving pain or discomfort. In addition to the solution above indicated, solutions of borax, of sulphate of zinc, of tannin and glycerin with chloroform, of nitrate of silver not too concentrated—2 to 10 centigrammes to 30 grammes of distilled water—tincture of aconite, solutions of the bromides, cocaine and other anæsthetics, may be used with benefit. In many cases the administration of general tonics along with the local treatment will be of the greatest value. The application of electricity to the parts through the surfaces—that is, from one side of the larynx to the other—will add to the efficacy of other local treatment. The strength of the current should not be so great as to give rise to any discomfort. The current should be continuous, and should be repeated every day for several weeks if the disorder does not yield sooner. In cases which have been induced by vicious habits of living or of exercise of the organ there should of course be an entire change of the habits. The producing cause should, if possible, be removed. The exposure of the parts to anything which gives rise to pain is to be avoided. If hyperæsthesia has been induced by unnatural methods of singing or of speaking, these should be remedied.

In neuralgia the general treatment for that affection is indicated. Quinine and iron have especially been found useful. In the hysterical variety of both hyperæsthesia and paræsthesia general treatment is of more value than local measures. General tonics, moral support, such as will be secured if we can convince the patient that there is really no serious trouble with the organ, but that it is only a morbid sensation, will be of the greatest value. In these cases change of climate, change of occupation, diversion by new associations, with expectation of recovery on the part of the patient, often bring about the most satisfactory results. The diagnosis should be certain and the physician should be able to speak with confidence in the matter. This will go far toward effecting a cure. For the purpose of diminishing the general irritability of the system bromine in some of its combinations, potassium, sodium, iron, quinine, etc., may be useful.