© Borgis - New Medicine 4/2007, s. 89-90
*Lidia Zawadzka-Głos1, Anna Jakubowska2, Michał Brzewski2, Mieczysław Chmielik1
Movement of vocal cords in endoscopic and ultrasonography examination
1Department of Pediatric Otolaryngology, Medical University of Warsaw, Poland
Head of Department: Prof. Mieczysław Chmielik, MD, PhD
2Department of Paediatric Radiology, Medical University of Warsaw, Poland
Head of Department: Prof. Andrzej Marciński, MD
Summary
Summary
Vocal cords paralysis is a frequent problem. Paralysis of the vocal cords in the newborn may be bilateral or unilateral and complete or partial. Bilateral vocal cord paralysis is more common than unilateral. The position of the vocal cords will usually correlate with the symptoms. Because of the correlation with other pathology, children with vocal cord paralysis should be investigated for intrathoracic and intracranial pathology. Definitive diagnosis is made by viewing the cords when the patient is awake. Cord mobility can be assessed by direct laryngoscopy and ultrasonography examination.
In Department of Paediatric Otorhinolaryngology in Warsaw, between 1998 and 2007, 56 children with vocal cords paralysis were admitted. There were 22 girls and 34 boys with ages varying from 9 days to 15 years. Endoscopic and ultrasonography examination were used for diagnosis. The US examination was performed using a high frequency transducter 7-12 MHz. Results of those examination were compared. Endoscoping findings correlated with ultrasound findings in 100% of cases. Laryngeal US is well tolerated, safe and non-invasive method of examination but the final diagnosis is based on laryngoscopy.
INTRODUCTION
Paralysis of the vocal cords in the newborn may be bilateral or unilateral and complete or partial. Familial bilateral abductor paralysis has been described. Some patients have transient paralysis, which usually subsides within four to six weeks of birth. This condition is thought to occur at birth as a result of trauma to the recurrent laryngeal nerve where it crosses the cricothyroid joint. Bilateral vocal cord paralysis is more common than unilateral.
The position of the vocal cords will usually correlate with the symptoms. Vocal cord position will help the laryngologist to determine whether the problem is unilateral or bilateral and whether it is caused by injury to the superior laryngeal nerve or to the recurrent laryngeal nerve or both.
Injury to the external branch of the superior laryngeal nerve will result in paralysis of the cricothyroid muscle on the side of the injury. Since the superior laryngeal nerve serves as both a tensor of the glottic musculature and a sensory nerve to the superior larynx, symptoms of its paralysis will include voice change because of loss of tension in the vocal cord and occasional aspiration.
Injury of the recurrent laryngeal nerve results in paralysis of all intrinsic muscles on that side. The vocal cord assumes a paramedian position, and there is no lateral motion on inspiration. If there is bilateral abductor paralysis, the voice may also be quite good because the vocal cords will come to rest close to the position of phonation. The airway will be poor because of lack of abduction during inspiration.
Complete paralysis can occur with injury to the vagus nerve above the point of departure of the superior laryngeal nerve. Patient with bilateral paralysis and respiratory obstruction will require a tracheostomy. Dyspnoea occurs when the breathing surface of the glottis is decreased by ľ.
Central paralysis can occur with various disorders such as perinatal asphyxia, Arnold-Chiari malformation, multiple congenital anomalies of central nervous system, Charcot- Marie- Tooth syndrome, Guillain- Barre syndrome, cerebral vascular hemorrhage and others.
Peripheral paralysis can be caused by the following: mediastinal and thoracic surgery, neck surgery, neck trauma, toxic and metabolic causes, inflammatory factors.
Because of the correlation with other pathology, children with vocal cord paralysis should be investigated for intrathoracic and intracranial pathology. Definitive diagnosis is made by viewing the cords when the patient is awake. This can be done with flexible laryngoscope. If the flexible laryngoscope is not tolerated, cord mobility can be assessed by direct laryngoscopy and ultrasonography examination. At the direct laryngoscopy, the subglottic area of the larynx should be inspected for concomitant subglottic stenosis.
MATERIAL AND METHOD
In the Department of Paediatric ENT in Warsaw, between 1998 and 2007, 56 children with dyspnoea and voice disorders were admitted. There were 22 girls and 34 boys with ages varying from 9 days to 15 years. In 19 cases congenital abnormalities and diseases of the central nervous system were found. In 27 cases congenital defects of cardiovascular system were found in the past, or cardiosurgical intervention had been performed. In 5 children neck trauma had occurred and in 5 cases we could not establish the etiology of the vocal cord paralysis.
In all children direct laryngoscopy and US examination were performed. The direct laryngoscopy was used to evaluate the anatomical structures and function of the larynx. The US examination was performed using a high frequency transducter 7-12 MHz. The examination included, apart from the larynx and the entire neck area, the oral cavity floor. The results of laryngeal sonography were compared with those of direct laryngoscopy.
RESULTS
In the whole group of children being examined, 24 had bilateral vocal cord paralysis and unilateral vocal cord paralysis was found in 32 children. Tracheotomy was done in children with bilateral vocal cord paralysis, which had led to considerable stenosis of airways. In the group of children with unilateral vocal cord paralysis 20 had left-sided vocal cord paralysis and 12 children right-sided.
Preliminary diagnoses were 100% confirmed by ultrasonography examination of the larynx with a clinical diagnosis. In the group of children with unilateral vocal cord paralysis there were 5cases in whom differences in determination of affected side.
DISCUSSION
Clinical manifestations of vocal cords paralysis are different. The infant has a weak or hoarse cry, inspiratory stridor, and difficulty with feeding. Stridor is most marked during activity and crying and often disappears at rest if paralysis is unilateral. Bilateral paralysis causes more severe obstructive symptoms. Diagnosis is made by direct laryngoscopy with anesthesia. Unilateral paralysis is usually well tolerated by the infant. Bilateral paralysis will almost always require a tracheotomy.
Direct laryngoscopy is an invasive examination but enables direct inspection of larynx, and undertaking of diagnostic and therapeutic procedures. New diagnostic techniques such as ultrasonography make it possible to reveal causes and confirm diagnosis in a quicker and more detail way. Endoscoping findings correlated with ultrasound findings in 100% of cases.
CONCLUSIONS
1. Laryngeal US is well tolerated, safe and non-invasive method of examination.
2. US is a useful adjunct to endoscopy in the diagnosis of vocal cord palsy.
3. Laryngoscopic results fully confirmed the initial US diagnosis
4. US of larynx should precede laryngoscopy and can be used in follow up evaluation.
5. The final diagnosis is based on laryngoscopy.
Piśmiennictwo
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