Laryngeal paralysis of childhood. It is characterized by stridor and inspiratory dyspnea that increases with crying , feeding, and straining. In the case of paralysis in abduction, it is accompanied by dysphagia and aspiration. We present a case of adduction of bilateral laryngeal paralysis of possible central etiology.
The superior laryngeal nerve provides a sensory internal branch that leads to the supraglottis, glottis, and part of the subglottis. If paralysis of this branch occurs, the patient has a tendency to aspire for abolition of the cough reflex . The external branch is motor and supplies the cricothyroid muscle, so its paralysis produces: chordal hypotonia in phonation. Furthermore, the contraction of oblique fibers of the contralateral cricothyroid produces rotation of the posterior commissure towards the opposite side of the lesion.
Summary
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- 1 Etiology
- 2 Clinical manifestations
- 3 Diagnosis
- 4 Treatment
- 5 Sources
Etiology
The usual cause is some form of trauma , whether it be acute injury at birth or chronic progressive mechanical trauma.
Trauma at birth may be secondary to lateral traction on the neck by releasing the shoulders, or to constriction of the neck by the umbilical cord . The right vocal cord is paralyzed more frequently, possibly due to excessive tension on the right recurrent nerve, which occurs more easily due to the intimate relationship of the right subclavian artery with movements of the shoulder and arm . The paralysis is usually unilateral, but bilateral paralysis may occur.
Chronic mechanical trauma is generally secondary to abnormalities of the nervous system or skull that causes traction on the vagus and accessory nerves in the region of the jugular foramen. An example is Arnold Chiari Syndrome, which is due to the displacement of the cerebellum and the bulb inside the vertebral canal due to the fixation of the spinal cord by a myelomeningocele or by a progressive internal hydrocephalus , which tends to increase the bulbar displacement .
As the bulb moves caudally, the fibers of the vagus and spinal accessory nerves distend, causing paralysis. Platybasis is a congenital disease of the skull base, which can cause bilateral paralysis secondary to stretching of the vagus nerve in the jugular foramen.
Clinical manifestations
The symptoms may appear at the time of birth or shortly thereafter the same time, although sometimes can be late start. Symptoms of unilateral paralysis due to obstetric injury are usually seen within 24 hours of delivery and include hoarse cry and stridor during deep inspiration. While the child is crying it may become cyanotic, but at rest or during sleep, the breaths are relatively normal and the stridor is missing.
The paralysis associated with Arnold Chiari Syndrome is often late onset, and even occurs after several weeks. Symptoms are characterized by accentuated stridor, feeding difficulties and, finally, laryngeal obstruction due to complete bilateral paralysis. Initially, this type of paralysis is reversible, and often disappears when hydrocephalus improves.
Diagnosis
The diagnosis is established by direct laryngoscopy. The laryngoscope should be inserted into the vallecule to inspect the movement of the vocal cords . If the tip of the laryngoscope is inserted into the larynx , it can tighten the strings and give the false impression of paralysis.
The paralyzed rope tends to be in the paramedic position and bow. When bilateral paralysis exists, the glottis is elliptical, with the widest opening located at the level of the center of the membranous vocal cords during inspiration.
Because the soft parts of the infant larynx are normally limp, considerable movement occurs during respiration that may give the false impression of normal function. The immobility of one or both arytenoids is the most important diagnostic finding.
Treatment
In a high percentage of cases, unilateral paralysis of the right vocal cord in a child due to a probable obstetric injury, is followed by recovery within six weeks or less, for this reason, rarely requires treatment. When the left vocal cord is paralyzed, the possible existence of congenital heart disease should be suspected or ruled out. If unilateral vocal cord paralysis persists, any deficits make up for it, and generally quite well, the vocal cord.
Bilateral paralysis may be due to obstetric trauma or be of unknown cause. In this case, spontaneous recovery of one or both cords occurs in a high percentage of cases, however, respiratory obstruction may occur before recovery and then a temporary tracheotomy is required.
When bilateral paralysis is associated with an abnormality of the nervous system , it happens as in the case of Arnold Chiari Syndrome, with the relief of hydrocephalus by ventricular drainage, an immediate response of the function is usually obtained, which is observed in essential cases. early. Permanent relief of hydrocephalus is necessary to avoid the reappearance of paralysis, in this case it may be convenient to resort to the insertion of a Holter valve, or perhaps proceed to a high cervical laminectomy.
If the paralysis is persistent, a permanent tracheostomy is required until age four or five. For speech development, the use of a tracheostomy tube with a valve is helpful. By the age of four or five years, lateral fixation of the arytenoid can be performed.
