PROGRESSIVE LABIO-GLOSSO-LARYNGEAL PARALYSIS.
BY H. D. SCHMIDT, M.D.
SYNONYMS.—Chronic progressive bulbar paralysis; Progressive muscular paralysis of the tongue, soft palate, and lips.
HISTORY.—Although the particular group of symptoms constituting this disease must have been met with and known to the older medical observers, they were nevertheless first recognized as a special variety of paralysis in 1841 by Trousseau,1 who named the affection labio-glosso-laryngeal paralysis. But as the memorandum prepared by this distinguished physician at the time when, in consultation with a medical colleague, he had observed the particular symptoms of this affection, unfortunately remained unpublished, twenty years more elapsed before the first accurate and detailed description of the symptoms and progressive nature of this disease under the name of progressive muscular paralysis of the tongue, soft palate, and lips was rendered by Duchenne. The writings of this author directed at once the attention of other medical men to this disease, and since that time a large number of cases have been reported and discussed,2 while the microscopical examination accompanying the autopsies of many of them finally revealed that the seat of the lesion giving rise to the phenomena of this disease was to be sought in the nervous nuclei of the medulla oblongata. Hence at the present time the pathology of this disease is thoroughly understood.
1 Clinique médicale de l'Hôtel Dieu de Paris, vol. ii. p. 334.
2 A very considerable number of cases of this disease, and discussions thereon, will be found reported in Virchow and Hirsch's Jahresbericht über die Leistungen und Fortschritte der Gesammten Medizin, for the years 1866-80, vol. ii., section “Krankheiten des Nervensystems.”
DEFINITION.—That form of labio-glosso-laryngeal paralysis to be treated in the following pages is characterized by a progressive paralysis and atrophy of the muscles of the tongue, lips, palate, pharynx, and larynx, interfering in a greater or lesser degree with the articulation of words and sounds and with the functions of mastication and deglutition—affecting, furthermore, in the later stages of the disease, the voice and the function of respiration. The paralysis is caused by a progressive degeneration and atrophy of the ganglion-cells of those nerve-centres in the medulla oblongata from which the muscles of the above-named organs receive their supply of nervous energy, though in most cases the pathological process extends to, or even beyond, the roots of those nerves which originate in these centres and terminate in the respective muscles. In many cases the pathological process extends to the spinal marrow, and there causes paralysis and atrophy of the muscles of the trunk, and, generally, of the upper extremities. Almost in every case the disease, as its name indicates, slowly progresses until it terminates in death.
There are, however, a number of cases observed which, though exhibiting the same or similar symptoms, do not, in reality, depend upon a progressive degeneration and atrophy of the centres and nerve-roots of the medulla, but, on the contrary, owe their symptoms to other causes; as, for instance, to tumors, hemorrhages, syphilitic neoplasms, etc., which, either by pressing upon the medulla from without, or, if situated within, by deranging in various manners the individual nervous elements of that part, may give rise to some or even all of the symptoms of true labio-glosso-laryngeal paralysis. These symptoms, however, according to the character of the lesion, may, after remaining stationary for some time, retrograde, and even disappear, as has been observed in syphilitic cases; or they may progress, and finally end in death. In order to distinguish these cases from the chronic or progressive bulbar paralysis some authors have attached the term retrogressive to this form of the disease.
SYMPTOMS.—As the degeneration of the nerve-centres in the medulla oblongata, upon which the disease depends, does not proceed in a regular fixed order, the order in which the clinical symptoms successively appear also varies in different cases. In the majority of cases, however, the symptoms appear gradually, manifesting themselves generally in the form of a greater or lesser impediment in the articulation of certain sounds or letters depending upon the movements of the tongue, such as e, i, k, l, s, and c, while at the same time a difficulty of mastication and deglutition may be experienced by the patient, due to the progressive development of the paralysis, which deprives the tongue of its lateral and forward movements. To this cause also, at this period, the apparently increased secretion of saliva, running from the corners of the mouth, must be attributed. With intelligent patients these symptoms are rendered less prominent by the special effort which they make to pronounce slowly for the purpose of hiding the deficiency in their speech. But as the disease advances the difficulty of articulation increases on account of the paralysis extending to the orbicularis oris, thus affecting the mobility of the lips and interfering with the pronunciation of the labial sounds p, b, f, m, and w. With the loss of power of articulation the patient's speech becomes gradually reduced to monosyllables, or even, finally, to incomprehensible and inarticulated grunts, by which he expresses his wants to his friends. In consequence of the paralysis of the lips the patient becomes unable to whistle or blow or to perform any movement depending upon these organs, while at the same time, through the disturbance created in the co-ordination of the facial muscles by the paralysis of the orbicularis oris, the mouth becomes transversely elongated and drawn downward by the action of the remaining unparalyzed muscles upon its angles. With the mouth partially open and the lower lip hanging down, the face of the patient has a peculiar sad and painful expression, while the voice assumes a nasal sound on account of the paralysis of the palate.
After a while the difficulty of deglutition, caused by the inability of the tongue to properly assist in the formation of the bolus of food and its propulsion into the pharynx, increases on account of the paralysis extending to the muscles of the pharynx. The failure of these muscles in the performance of their special function of grasping the food and carrying it to the œsophagus obliges the patient to push it down the pharynx with his fingers. In some cases the difficulty of swallowing rests with solids, in others with fluids. The defective deglutition furthermore gives rise to spells of coughing and suffocation by portions of food getting between the epiglottis and larynx, while the paralyzed muscles of the palate allow the fluids to pass through the nose and enter the posterior nares.
As the case slowly proceeds the symptoms grow worse. The paralysis of the orbicularis oris reaches a point when this muscle is no more able to close the oral cavity; the mouth of the patient therefore remains open. The tongue, having now entirely lost its lateral, forward, or upward movements, rests motionless upon the floor of the mouth, evincing no other signs of life but occasional slight muscular twitchings. In some cases a diminution of the sense of taste, and also of that of touch in the tongue, pharynx, and larynx, has been observed. Atrophy of the tongue and lips now sets in, and the function of speech is almost entirely lost. The only letter which the patient is still able to pronounce is a (broad); all other sounds are indistinct and can hardly be understood. The paralysis of the tongue and other muscles of deglutition gives rise, furthermore, to an accumulation of the now excessively secreted saliva, which, being retained in the oral cavity, assumes the form of a viscid mucous liquid dripping from the mouth, extending, in the form of strings or ribbons, between the surfaces of the lips. Finally, when, through the progressive paralysis of the orbicularis oris, the patient can no more close the lips, the flow of saliva from the mouth becomes continuous; he is then seen engaged in the constant use of his handkerchief for removing the secretion.
In the latter stages of the disease the pathological process extends to the centres of respiration, paralyzing not only the muscles of respiration, but diminishing at the same time the contractile power of the lungs. A great difficulty of breathing—consisting not only in the want of depth of the inspirations, but, moreover, in a feebleness of expiration (manifested by weak, powerless coughing)—then ensues, and the patient is no further able to blow his nose or clear his bronchial tubes from the accumulating mucus. The paralysis of the muscles of the larynx, also occurring at this stage, not only increases the difficulties of deglutition, but most seriously affects the voice of the patient by decreasing the innervation of the vocal cords; the voice then becomes hoarse and weak, to be finally entirely lost.
The decrease in the innervation of the heart—which, lastly, also occurs—gives rise to irregularities in the action of this organ, followed by irregularity of the pulse, attacks of syncope, feelings of extreme weakness, and fears of death; whilst simultaneously the insufficient performance of the respiratory function renders the breathing of the patient weaker and weaker. Feelings of great oppression in the chest then arise, and the patient may die during one of the now frequent attacks of dyspnœa and suffocation.
No fever or pain is observed during the course of this disease; sensation remains unaffected and the mind is perfectly clear. It is owing to these circumstances that frequently the patient walks about and attends to the duties of life, until shortly before death he becomes confined to bed by the great weakness caused by the want of nutrition. The appetite also remains good, but, unfortunately, in consequence of the difficulties attending the act of deglutition, the patient cannot satisfy the demands of his stomach. In the latter stages of the disease, therefore, when feeding can only be accomplished by the aid of the stomach-tube, every attempt to relieve the terrible gnawings and pains of hunger ends in a failure. With starvation staring in his face, the unhappy victim of the disease finally sinks into a state of extreme inanition, which, if life is not suddenly extinguished by an attack of suffocation, slowly leads to final dissolution.
The symptoms above described are those generally observed in uncomplicated cases of labio-glosso-laryngeal paralysis. There are, however, a number of cases reported in which the degenerative process has passed from the medulla oblongata to the spinal cord, and given rise to paralysis of the muscles of the neck, especially of the trapezius, and to those of the shoulders, and even to those of the upper extremities. Atrophy of the interosseus muscles of the hand, with those of the ball of the thumb, is not unfrequently observed. In other cases the disease has been found associated with progressive muscular atrophy, and in others, again, with paralysis of the lower extremities, accompanied by contractures and depending upon amyotrophic lateral sclerosis.
Labio-glosso-laryngeal paralysis is, as before mentioned, slow but progressive in its course, the duration of which is from one to three, or even five, years. It always terminates in death within the limits of this time, either from suffocation, inanition, paralysis of the heart, or some other intercurrent disease.
PATHOLOGICAL ANATOMY.—The macroscopical and microscopical examinations made during the last fifteen years of the cerebro-spinal axis in quite a number of cases of progressive labio-glosso-laryngeal paralysis show that this disease depends upon a degeneration of the nervous elements of the nuclei or nerve-centres in the medulla oblongata, involving also the roots of the nerves arising from the latter, and supplying with nervous energy the muscles of the different organs paralyzed in this disease. The exact nature of this degeneration—that is, whether it represents the sequel of a previously existing myelitis or originates in a so-called parenchymatous inflammation—appears to be as yet not definitely settled, though a number of pathologists entertain the view that it is preceded by a chronic myelitis. This view appears to be corroborated by the fact that frequently portions of the medulla oblongata and cervical portion of the spinal cord are found in a state of sclerosis. The uncertainty in the determination of the exact nature of the pathological process here concerned chiefly depends upon the diverse conditions in which the blood-vessels of the medulla are found. For while, in some cases, perhaps the majority, they have been found empty and in a normal condition, they have in others been met with congested with blood—a condition pointing to a chronic inflammatory process. In other cases, again, their walls have been found thickened or undergoing fatty degeneration.
At any rate, whether inflammatory or not, the now numerous microscopical examinations have revealed that the main features of the process are a degeneration and atrophy, not only of the ganglion-cells of the respective nervous nuclei with their plexuses, but also of the fibres of the roots of the peripheral nerves arising from these centres; frequently the degeneration extends to some distance upon the nerves themselves. The microscopical changes in the ganglion-cells consist of an increase of yellow pigment, a gradual disappearance of their nuclei, terminating in an atrophy of the ganglionic bodies themselves, the pathological process leaving, finally, nothing but irregularly-shaped masses of pigment in the places of these bodies. The degeneration of the nerve-fibres appears to consist, as elsewhere, in a swelling of the axis-cylinder, accompanied by atrophy of the medullary sheath—a condition which finally leads to the complete destruction of these elements of the nerve-fibres, so that, at last, the whole nerve is only represented by the connective tissue of its neurolemma. Besides these changes, certain pathological products, such as conglomerations of fatty granules or globules, amylaceous bodies, etc., are also found in the degenerated nerve-centres and nerve-fibres.
Although in different cases the route which the degenerative process pursues is not the same, a certain general order, in which the nerves and nerve-centres are successively affected, and corresponding to the clinical symptoms, appears, nevertheless, to exist. It is thus that the nucleus of the hypoglossus has been observed to degenerate before the other nerve-centres. The nuclei of the spinal accessory and pneumogastric nerves, and also that part of the facial nucleus from which the inferior division of the facial nerve arises, appear to be affected next. The glosso-pharyngeal nucleus appears not to be affected in all cases, and still less frequently the nuclei and roots of the abducens, auditory, and trifacial nerves. The fibres forming the anterior pyramids have frequently been found degenerated throughout the medulla oblongata and pons; sclerosis also has been met with in this locality. In many cases, as has been remarked before, the pathological process descends into the spinal cord. Here, as in the medulla oblongata, the degeneration is principally confined to the motor centres located in the anterior horns, while the posterior horns, together with the lateral and posterior white columns, remain free from disease. The degree of degeneration taking place in the fibres of the respectively paralyzed muscles also corresponds to that of the elements of the nerve-centres from which they are supplied. The microscopical changes observed in the muscular fibres consist in a decrease of their diameter, accompanied by an increase in the number of their nuclei, as well as in the quantity of the connective tissue surrounding the primary bundles; some authors have observed amyloid degeneration of the muscular fibres.
ETIOLOGY.—The causes which give rise to the pathological process above described are but little known. Nevertheless, in a number of cases the disease has been traced back to taking cold, to physical as well as cerebral over-exertion, mental excitement, sorrow caused by misfortunes, poverty of nutrition, excessive use of tobacco, etc. In some cases the disease commences in the spinal cord in the form of progressive muscular atrophy or amyotrophic lateral sclerosis, and gradually extends to the medulla oblongata; in many other cases no particular cause can be found. The disease is rarely if ever met with in persons under twenty years of age, but is confined to adult life and old age. It occurs in both high and low walks of life, attacking more frequently men than women.
DIAGNOSIS.—The symptoms of progressive labio-glosso-laryngeal paralysis are so characteristic in themselves as to exclude any mistake in the formation of a diagnosis. There are, nevertheless, some pathological conditions, such as hemorrhages in the medulla oblongata or thrombosis and embolism of the arteries supplying the latter with blood, which may give rise to the same or very similar phenomena, and thus render a correct diagnosis difficult. In such cases it must be remembered that the cause of true labio-glosso-laryngeal paralysis, depending upon degeneration and atrophy of the nervous nuclei along the floor of the fourth ventricle, is very gradual, while the symptoms produced by the causes before mentioned generally make their appearance in a more acute and sudden manner. The latter also, if not remaining stationary for some time, have rather a tendency to improvement, wanting, therefore, the progressive character of the former.
Tumors at the base of the brain also, by pressing upon the roots of the cerebral nerves or upon the medulla oblongata itself, may produce similar symptoms, which, on account of their comparatively slow and gradual development, may prove more difficult to distinguish from those characterizing genuine, progressive labio-glosso-laryngeal paralysis. Errors of diagnosis, however, may here be avoided by taking into consideration the special symptoms which generally accompany the presence of tumors of the brain, such as vertigo, headache, vomiting or even hemiplegia, and local paralysis. The sensory nerves also may become affected by the pressure of the tumor upon them. Thus, pressure upon the trifacial nerve may give rise to neuralgic pains, feelings of tingling and numbness, or even anæsthesia; while pressure upon the optic nerves or their tracts, or upon the olfactory and lingual nerves, will be followed by derangements of vision, smell, and taste. The symptoms produced by the pressure of a tumor at the base of the brain, moreover, are not strictly progressive, but may for some time appear, and disappear again before becoming permanent.
Facial diplegia, in which the expression of the face somewhat resembles that of a patient affected with labio-glosso-laryngeal paralysis, is distinguished from the latter disease by the paralysis affecting both divisions of the facial nerve, while the tongue remains free and deglutition is undisturbed.
There are still other affections of the cerebro-spinal axis, such as paralysis of the insane, disseminated sclerosis, etc., which in their course present some or perhaps all of the symptoms characterizing labio-glosso-laryngeal paralysis; these may be distinguished from the latter disease by taking their own special symptoms into consideration.
TREATMENT.—Although almost all cases of progressive labio-glosso-laryngeal paralysis terminate fatally, some cases have been reported by several observers in which a temporary improvement in the symptoms of the disease, or even a total cure, had been obtained by treatment. Of course such favorable results can only be obtained in the initial or earlier stages of the disease. Thus, Kussmaul recommends in the initial stage, when pains in the head and neck are present, wet cupping of the nape of the neck in strong persons, also the use of the shower-bath, while nitrate of silver may be given internally. The application of galvanism in an alternate direction he also recommends—first, through the neck, and later on through the whole spinal column—and at the same time currents in an alternating direction from the neck and hypoglossus nerve to the tongue. Dowse reported a case of bulbar paralysis which he cured by the application of the constant current upon the paralyzed parts, subcutaneous injections of atropine and strychnine, with the internal administration of cod-liver oil, quinine, and phosphorus. He attaches great importance to the careful feeding of the patient through a tube passed through the nose, and to the strict application of the galvanic current; for excessive salivation he recommends atropine. Erb recommends to regulate the diet and the habits of life of the patient in such a manner as to avoid every irritation of the nervous system; furthermore, to generally stimulate the nutrition in order to produce a tonic effect upon the nervous system. For this purpose he principally relies upon a cautious hydropathic treatment, to be continued for a long time and with great regularity. The greatest importance, however, he attaches to electricity, considering the best method of galvanism as follows: “Galvanize with stabile application transversely through the mastoid processes and longitudinally through the skull, the so-called galvanism of the cervical sympathetic (anode on the nuchus, and cathode at the angle of the lower jaw), and then induce movements of deglutition (twelve to twenty at each sitting); besides this, apply, according to circumstances, direct galvanic or faradic currents to the tongue, lips, and palate.” The electric treatment must be continued for some time, with from four to seven sittings a week. Of the medicines taken internally, Erb recommends nitrate of silver, iodide of potassium, iodide of iron, chloride of gold and sodium, ergotin, belladonna, and preparation of iron and quinine.