Neurogenic dysphagia: causes, symptoms, diagnosis, treatment

The swallowing function consists in precisely controlled transport of the food lump and fluid from the mouth into the esophagus. Since the air and food streams, crossing, have a common path in the mouth and throat, there is a thin mechanism of their separation during swallowing to prevent ingestion of ingested food in the airways. The oral preparatory phase, the actual oral swallowing phase and the swallowing reflex are singled out. To the food lump passed through the esophagus, a reflex mechanism is activated. In this case, the essential elements of swallowing are the exclusion of the nasopharynx (nasopharynx) with the help of bicycle pharyngeal overlapping, pushing the lump into the pharynx with the help of the pumping tongue, overlapping the larynx with the epiglottis and pharyngeal peristalsis, which displaces the food through the cricopharyngeal sphincter into the esophagus. Lifting the larynx helps to prevent aspiration and raising the base of the tongue, which facilitates pushing food down into the pharynx. The upper airway is closed by the approximation and tension of the epiglottis, the lower by false vocal cords and, finally, by the true vocal cords that act as a valve preventing food from entering the trachea.

Entry into the airway of a foreign material usually causes a cough that depends on the strain and strength of the expiratory muscles, including the abdominal muscles, m. Latissimus and m. Pectoralis. The weakness of the palatine curtain causes a nasal shade of the voice and the ingestion of liquid food into the nose upon swallowing. Weakness of the language makes it difficult to perform the most important pumping function of the language.

The coordination of swallowing depends on the integration of the sensory pathways from the tongue, the oral mucosa and the larynx (cranial nerves V, VII, IX, X) and the inclusion of arbitrary and reflex contractions of the muscles innervated by the V, VII and X-XII nerves. The medullary center of swallowing is located in the region of the nucleus tractus solitarius very close to the respiratory center. Swallowing is coordinated with the phases of breathing in such a way that swallowing apnea should be followed by inhalation, preventing aspiration. Reflex swallowing remains normally functioning even with a persistent vegetative state.

[1], [2], [3], [4]

The main causes of dysphagia:

I. Muscular level:

1. Myopathy (oculo-pharyngeal).
2. Myasthenia gravis.
3. Dystrophic myotonia.
4. Poliomyositis.
5. Scleroderma.

II. The neural level:

A. One-sided damage. Poorly expressed dysphagia (defeat of the caudal group of nerves with fracture of the base of the skull, jugular vein thrombosis, glomus tumor, Garsen's syndrome, rarely - with multiple sclerosis).

III. Bilateral lesions:

1. Diphtheria polyneuropathy.
2. Tumor in the base of the skull.
3. Polyneuropathy Guillain-Barre.
4. Idiopathic cranial polyneuropathy.
5. Meningitis and carcinomatosis of the membranes.

III. Nuclear Level:

A. One-sided damage:

1. Mainly vascular lesions of the trunk, in which dysphagia is represented in the picture of the alternating syndromes of Valenberg-Zakharchenko, Sestan-Shene, Avellis, Schmidt, Tepia, Berne, Jackson.
2. Rareer causes: syringobulbia, brain stem glioma, Arnold-Chiari malformation.

B. Two-sided lesions (bulbar palsy):

1. Amyotrophic lateral sclerosis.
2. An infarction or hemorrhage in the medulla oblongata.
3. Polio.
4. Syringobulbia.
5. Progressive spinal amyotrophy (bulbar forms in children, bulbospinal form in adults).

IV. The supranuclear level (pseudobulbar palsy):

1. Vascular lacunar state.
2. Perinatal trauma.
3. Craniocerebral injury.
4. Amyotrophic lateral sclerosis.
5. Degenerative atrophic diseases involving pyramidal (pseudobulbar syndrome) and extrapyramidal system (pseudo-pseudobulbar paralysis), including progressive supranuclear palsy, Parkinson's disease, multiple systemic atrophy, Pick's disease, Creutzfeldt-Jacob disease, etc.
6. Hypoxic encephalopathy.

V. Psychogenic dysphagia.

I. Muscular level

Diseases that affect the muscles directly or the myoneural synapses can be accompanied by dysphagia. Oculopharyngeal myopathy (oculopharyngeal dystrophy) is a variant of hereditary myopathy, characterized by a late onset (usually after 45 years) and manifested by the weakness of a limited number of muscles, mainly by slowly progressive bilateral ptosis and dysphagia, and by a change in voice. In later stages, it is possible to involve the muscles of the trunk. These very characteristic clinical features serve as a basis for diagnosis.

Myasthenia gravis debut (in 5-10%) as a monosymptomatic dysphagia. Attachment of fluctuating weakness in other muscles (oculomotor, facial muscles and muscles of the extremities and trunk), as well as electromyographic diagnostics with proserin probe confirm the diagnosis of myasthenia gravis.

Dystrophic myotonia as a cause of dysphagia is easily recognized on the basis of a typical autosomal dominant type of inheritance and a unique topography of muscular atrophy (m. Levator palpebre, mimic, chewing including temporal, nipple muscles, and muscles of forearms, brushes, and shins). Characteristic dystrophic changes in other tissues (lens, testes and other endocrine glands, skin, esophagus and, in some cases, the brain). There is a characteristic myotonic phenomenon (clinical and EMG).

Poliomyositis is an autoimmune disease characterized by early swallowing disorder (bulbar syndrome of myogenic nature), proximal muscle weakness with myalgias and muscle tightens, preserved tendon reflexes, high CPC level, changes in EMG and in biopsy of muscle tissue.

Scleroderma can affect the esophagus (esophagitis with a characteristic X-ray picture), manifested by dysphagia, which is usually detected against the background of a systemic process that affects the skin, joints, internal organs (heart, lungs). Reynaud's syndrome often develops. In iron deficiency anemia, the atrophic changes in the mucous membrane of the pharynx and esophagus, as well as the spastic narrowing of its initial part (Plummer-Vinson syndrome), are an early symptom and sometimes precede the development of anemia. Hypochromic anemia and a low color index are revealed.

II. The neural level

A. One-sided damage

Unilateral damage to the caudal group of nerves (IX, X and XII pairs), for example, with fracture of the base of the skull, usually causes mild dysphagia in the picture of the Berne syndrome (jugular hole syndrome, manifested by unilateral involvement of IX, X and XI pairs). This syndrome is also possible with thrombosis of the jugular vein, a tumor of the glomus. If the fracture line passes through a nearby channel for the sublingual nerve, the syndrome of unilateral defeat of all caudal nerves (IX, X, XI and XII nerves) develops with more pronounced dysphagia (Vernet-Sikar-Kolle syndrome). Garsen's syndrome is characterized by the involvement of cranial nerves on the one hand ("half of the base" syndrome) and therefore besides dysphagia has many manifestations of involvement of other cranial nerves. Multiple sclerosis can be a rare cause of unilateral damage to the root of the caudal cranial nerves and is accompanied by other characteristic symptoms of this disease.

B. Bilateral lesions

Bilateral lesions of the caudal cortical nerve trunks are characteristic mainly for some polyneuropathies and shell processes. Diphtheria polyneuropathy, as well as OVDP or some other variants of polyneuropathies (postvaccinal, paraneoplastic, in hyperthyroidism, porphyria) can lead to severe tetraplegia with sensitive disorders, tabloid and other stem disorders up to paralysis of respiratory muscles (Landry type) and complete loss of self-swallowing .

Idiopathic cranial polyneuropathy (idiopathic multiple cranial neuropathy) is less common and can occur as a one-way or as a two-way process. It is characterized by a sharp onset with the onset of headache or facial pain, more often in the periorbital and frontotemporal region. The pain is constantly aching, it can not be attributed to either the vascular or the neuralgic type. Usually after a few days there is a picture of the sequential or simultaneous involvement of several (at least two) cranial nerves (III, IV, V, VI, VII nerves, possibly involving the 2nd pair and caudal group of nerves). The olfactory and auditory nerves are not involved. Perhaps both monophasic and recurrent. Pleocytosis in CSF is not typical; possible increase in protein. Typical good therapeutic effect of glucocorticoids. The disease requires the exclusion of symptomatic cranial polyneuropathy.

For carcinomatosis of the meninges, bilateral sequential (with an interval of 1-3 days) involvement of the cranial nerves is characteristic. Tumors of the base of the skull (including those with Garsen's syndrome), the blumenbeach ramp or caudal sections of the brainstem are accompanied by the involvement of V-VII and IX-XII and other nerves. In these cases, dysphagia is observed in the picture of the defeat of several cranial nerves. Crucial diagnostic value is neuroimaging.

III. The nuclear level

A. One-sided damage

One-sided damage. The most common cause of unilateral damage to the nuclei of the caudal group of nerves is vascular lesions of the brain stem. In this case, dysphagia is represented in the picture of the alternating syndromes of Valenberg-Zaharchenko (more often), or (very rarely) Sestan-Schone, Avellis, Schmidt, Tepia, Berne, Jackson. The course of the disease and the characteristic neurological symptoms in these cases rarely gives rise to diagnostic doubts.

The more rare causes of unilateral damage to the caudal sections of the brain stem: syringobulbia, glioma of the brainstem, Arnold-Chiari malformation. In all cases, invaluable diagnostic help is provided by methods of neuroimaging.

B. Two-sided lesions (bulbar palsy)

Bilateral paralysis at the nuclear level can be caused by vascular, inflammatory and degenerative diseases affecting the caudal sections of the brainstem (oblong brain). The bulbar form of amyotrophic lateral sclerosis even in the early stages of the disease manifests itself as a violation of swallowing, which, as a rule, is accompanied by dysarthria, EMG signs of motor neuronal suffering (including in clinically preserved muscles) and a progressive course of the systemic process.

Infarction or hemorrhage in the medulla oblongata with bilateral damage always manifests itself in massive cerebral and focal neurological symptoms and dysphagia is a characteristic part of it.

Poliomyelitis in adults is usually not limited to lesions of bulbar functions; however, a bulbar form is possible in children (neurons VII, IX, and X nerves are usually affected). In diagnostics, in addition to the clinical picture, it is important to take into account the epidemiological situation and the data of serological studies.

Syringobulbia is characterized by symptoms of damage not only to the motor nuclei of the IX, X, XI and XII nuclei (dysphonia, dysarthria, dysphagia, with higher localization may involve the facial nerve), but also by characteristic sensitive disorders on the face according to the segmental type. The slow course of the disease, the absence of conductive symptoms in this form and the characteristic pattern of CT or MRI make diagnosis, not very difficult.

Progressive spinal amyotrophy, manifested by dysphagia, in children and adults takes place in different forms.

Syndrome Fazio-Londe (Facio-Londe), otherwise called progressive bulbar paralysis in children, is a rare hereditary disease that affects children, adolescents and young people. The disease usually begins with respiratory (stridor) disorders, which are then followed by diplegia facialis, dysarthria, dysphonia and dysphagia. Patients die several years after the onset of the disease. Upper motoneuron usually does not suffer.

Bulbospinal amyotrophy in adults, called Kennedy syndrome, is observed almost exclusively in men (the X-linked type of inheritance) most often at the age of 20-40 years and is characterized by a rather unusual combination of distal atrophy (first in the hands) with bulbar bulbar signs. There is a slight paretic syndrome, sometimes - episodes of general weakness. There are fascinations in the lower part of the face. Quite typical gynecomastia (about 50%). There is a tremor, sometimes - crampi. The flow is fairly benign.

IV. The supranuclear level (pseudobulbar palsy)

The most common cause of dysphagia in the picture of pseudobulbar syndrome is the vascular lacunar state. There is a picture not only of bilateral damage to corticobulbar pathways, but also bilateral pyramidal signs, gait disturbances (dysbasia), reflexes of oral automatism, often - urination disorders; often a violation of cognitive functions, on MRI - multiple foci of softening in the cerebral hemispheres in a patient with vascular disease (most often - hypertension).

Pseudobulbar syndrome is common in perinatal trauma. If the latter is accompanied by spastic tetraplegia, then gross speech disorders, respiratory difficulties and dysphagia are possible. As a rule, there are other symptoms (dyskinetic, atactic, violation of mental maturation, epileptic seizures and others).

Craniocerebral trauma can lead to various variants of spastic paralysis and expressed pseudobulbar syndrome with disorder of bulbar functions, including swallowing.

Amyotrophic lateral sclerosis in the onset of the disease ("high" form) can be clinically manifested only by signs of the upper motor neuron (pseudobulbar syndrome with no signs of atrophy and fasciculations in the tongue). Dysphagia is caused by spasticity of the muscles of the tongue and pharynx. Actually bulbar paralysis sometimes joins a bit later. A similar picture is possible with a form of amyotrophic lateral sclerosis, such as primary lateral sclerosis.

Dysphagia can be observed in the picture of various forms of multiple systemic degeneration and parkinsonism (idiopathic and symptomatic). This is a progressive supranuclear paralysis, multiple systemic atrophy (in three of its variants), diseases of diffuse Levy bodies, corticobasal degeneration, Parkinson's disease, vascular parkinsonism and some other forms of it.

At the majority of the specified forms in a clinical picture of disease there is a parkinsonism syndrome, among which displays the dysphagia sometimes reaching appreciable degree of expression at separate patients.

The most common etiologic form of parkinsonism, accompanied by dysphagia, is Parkinson's disease, whose diagnostic criteria are also unified, as are the criteria for the diagnosis of progressive supranuclear palsy, multisystem atrophy, cortico-basal degeneration and Disease of diffuse Levi bodies. In general, Parkinsonism in the picture of multisitem degeneration differs from the absence of resting tremor, early development of postural disorders, rapid rate of progression, and low effectiveness of prefacial preparations.

Rarely, dysphagia is caused by a dystonic spasm of the pharynx ("spastic dysphagia") or other hyperkinesis (dystonic, choreic), for example, with tardive dyskinesia.

V. Psychogenic dysphagia

Dysphagia in the picture of conversion disorders sometimes acts as the main clinical syndrome, leading to a pronounced decrease in body weight. However, the analysis of mental and physical status always reveals polysyndrome disorders (at the time of examination or taking into account anamnesis) developing against the background of actual (and child) psychogenesis in a person prone to demonstrative reactions. However, "neurological forms" of hysteria, as a rule, are observed in the absence of vivid personality disorders. Identifying accompanying visual, pseudo-tactical, sensorimotor, verbal (pseudo-hypocrisy, mutism), "coma in the throat", and other (including a variety of vegetative) disorders, provocation of which makes it possible to clarify their phenomenology and facilitate diagnosis. It is always necessary to exclude the somatic causes of dysphagia with an x-ray examination of the swallowing act. In a population of psychiatric patients, non-structured dysphagia is very common.

Differential diagnosis is performed with other forms of neurogenic dysphagia, refusal of food intake in the syndrome of negativism, visceral disorders (somatogenic dysphagia).

Diagnostic tests for dysphagia

Clinical and biochemical blood analysis, esophagoscopy and gastroscopy, X-ray examination of the upper gastrointestinal tract, chest x-ray, mediastinal tomography, EMG of the tongue muscles (with myasthenia), CT or MRI of the brain, investigation of CSF, thyroid hormone, EEG, consultation of the therapist, endocrinologist, psychiatrist.

[5], [6], [7]