Voice production

The larynx also provides the basic phonatory sound upon which a voice can be produced. Adduction of the vocal cords produces a constricted area where the air pressure is reduced as it passes from the lungs to the pharynx (Bernoulli’s phenomenon). The vocal cord mucosa is consequently sucked together, producing a rise in the subglottic pressure which forces the cords apart again. This cycle is repeated to produce vibration and hence sound. Volume changes are effected by alteration of the subglottic pressure. Pitch alterations occur by modifying vocal cord length and tension. The quality of the raw basic laryngeal phonatory sound is further altered by the resonating cavities of the pharynx, mouth and nose. Speech is ultimately produced by the interaction of the articulators (teeth, tongue, lips) on this phonatory sound.

Oral cavity

The major signs and symptoms of oral disease include:

Pain

Dental disease is the most common cause of pain in the oral cavity. Carious teeth are tender if subjected to temperature changes and on chewing. Periodontal disease can cause pain on tooth brushing and is associated with halitosis due to accumulation of decaying food debris. Dentures may cause pain if improperly sized, or if they provide an abnormal bite. Atrophy of the teeth-bearing alveolar ridges may result in dentures causing pain, and is commonly seen in the elderly. Maxillary sinusitis may result in toothache if a tooth root is projecting into the sinus mucosa (Fig. 3.6). Pain due to malignant disease is severe and constant, and invariably leads to some degree of dysphagia.

Fig. 3.6 X-ray showing indentation of tooth roots in the maxillary antra.

Oral masses

Any complaint of a lump requires palpation of the site, even if a lesion is not visible. Virtually all lumps require biopsy to exclude cancer. Tongue masses are nearly always neoplastic. One exception is the rare, median rhomboid glossitis which presents as a red area on the dorsum of the tongue and is benign (p. 83).

Blockage of a duct of the sublingual salivary gland may give rise to a cystic lesion called a ranula in the floor of the mouth. An exostosis of the hard palate, ‘torus palatinus’, has a typical position in the midline and is hard to palpation (Fig. 3.7).

Fig. 3.7 The torus palatinus is an osteoma of the hard palate, usually located in the midline.

Pharynx

The precise symptoms are dependent on which region of the pharynx is primarily involved. The majority of pathologies in the oropharynx and hypopharynx, either inflammatory or neoplastic, will lead to some degree of dysphagia (p. 76) (Fig. 3.8). Deafness may occur due to obstruction of the Eustachian tube with nasopharyngeal pathologies. Progressive nasal obstruction and epistaxis with otological symptoms should alert the clinician to nasopharyngeal malignancy. Large oropharyngeal masses may cause a voice change (‘hot potato voice’) and respiratory obstruction.

Fig. 3.8 Symptoms of disease in the three regions of the pharynx.

The alteration in voice in hypopharyngeal neoplasia is due either to direct infiltration of the larynx, by involvement of the recurrent laryngeal nerve with development of vocal cord palsy. Secondary nodal neck masses are very frequent with pharyngeal neoplasia and may be the presenting feature. Pain in pharyngeal disease may be localized to the throat, but is more usually referred to the ear.

Larynx

An alteration in voice (dysphonia) is the predominant symptom in laryngeal pathology. Respiratory difficulties usually occur late. Pain, difficulty in swallowing (dysphagia) or a lump in the neck in association with dysphonia may represent laryngeal malignancy. Aspiration of solids and liquids may occur with an incompetent larynx due to vocal cord paralysis, but is invariable in neurological disease producing sensory loss of the supraglottis.

Salivary glands

Pain and swelling are the two cardinal symptoms of pathology in the major salivary glands. Characteristics of the pain may lead to a specific diagnosis. If associated with mastication and some temporary swelling of the gland, particularly the submandibular, it may be due to an obstructive lesion in the salivary ducts. Continuous pain of increasing severity should heighten the suspicion of malignant disease.

A permanent enlargement of the salivary gland is neoplastic unless proven to the contrary. Sjögren’s syndrome may produce swelling of one or all of the major salivary glands. Certain endocrine disease (e.g. myxoedema) and drugs (e.g. oral hypoglycaemics) may cause salivary gland hypertrophy. A weakness of the facial nerve in parotid gland disease signifies malignancy.

Neck lumps

Persistent neck lumps should be investigated. This should include fine needle aspiration cytology (FNAC), with ultrasound guidance if available. A full examination of the upper air and food passages should be carried out and biopsies taken if malignancy is suspected.

Imaging

The value of plain radiology of the oral cavity is limited to viewing dental disease. Otherwise, computed tomography (CT) or magnetic resonance imaging (MRI) scanning is superior. However, lateral X-rays of the pharynx are useful, and may show evidence of abnormal shadowing. Contrast swallow studies may provide information on hypopharyngeal and oesophageal pathology (Fig. 3.10). A variety of radiological investigations of the salivary glands are available and are selected according to the suspected pathology (Table 3.2).

Fig. 3.10 A barium swallow showing a large filling defect in the pharyngo-oesophageal region.

Table 3.2 Imaging techniques available in salivary gland pathology

Biopsy

Any persistent mass or swelling should be biopsied. In the oral cavity this may be possible with simple local anaesthesia. Masses sited in the pharynx often require full assessment under a general anaesthetic, and special instrumentation is required for biopsy. All laryngeal masses require biopsy. Swellings of a major salivary gland can be biopsied by fine needle aspiration, which can readily be performed as an outpatient procedure. Excision biopsies are required in all other circumstances.

Acute laryngitis

Acute laryngitis is very common and frequently associated with an upper respiratory tract infection. It may also be non-infective, occurring after vocal abuse, e.g. shouting. There is invariably some pain in the throat. Resolution is spontaneous, although a degree of symptomatic relief is produced by steam inhalations and voice rest. If symptoms continue for more than 3 weeks, referral to an ear, nose and throat (ENT) specialist is mandatory.

Polyps

Unilateral inflammatory polyps are not uncommon (Fig. 3.11). The history is similar to acute laryngitis, but resolution of hoarseness cannot occur until the polyp is removed under microlaryngoscopic control. Inhalation of fumes, whether from tobacco, smoke or chemicals, may result in acute dysphonia. All inflammatory lesions, either infection or traumatic, may produce a sufficient degree of oedema to cause respiratory embarrassment.

Fig. 3.11 A large polyp arising from the right vocal fold.

Chronic laryngitis

Chronic dysphonia is frequently due to chronic laryngitis. The risk factors are smoking, alcohol, laryngopharyngeal reflux and vocal abuse. The larynx may show hypertrophic epithelium and leukoplakia (Fig. 3.12). Such an appearance may herald neoplastic change, so biopsy is mandatory. If neoplasia has been excluded, management is directed to avoiding known aetiological factors.

Fig. 3.12 Chronic hyperplastic laryngitis. The white appearance is leukoplakia.

Laryngopharyngeal reflux

Gastro-oesophageal reflux disease (GORD) is due to reflux of stomach contents above the lower oesophageal sphincter. Reflux above the lower oesophageal sphincter is called laryngopharyngeal reflux (LPR). The refluxate contains acid, enzymes (pepsin) and bile salts. All of these can be damaging to the larynx. Conventional 24 hour pH studies may not be diagnostic for LPR as they only screen for prolonged reflux episodes with a pH below 4. Transient reflux or less acidic refluxate may not produce heartburn (‘silent reflux’) but still lead to laryngeal symptoms such as dysphonia, cough and throat clearing. LPR is also a risk factor for laryngeal pathology such as chronic inflammation, vocal granulomas and even mucosal metaplasia (Fig. 3.12).

Spasmodic dysphonia

Spasmodic dysphonia is primarily a neurogenic disorder, although a small percentage of cases may be psychogenic in origin. The most common form is characterized by gross hyperadduction of the vocal cords. The voice is distinctive and variously described as ‘strained’ or ‘strangled’. However, during singing, crying and laughing, the voice may be normal. In some patients, the onset of symptoms is related to a major life event, e.g. bereavement, family conflicts or road accidents.

Conventional speech therapy techniques are beneficial in treating those cases of psychogenic origin, but have little effect on those of neurogenic aetiology. Treatment involves regular injections of botulinum toxin into the vocal folds to abolish neuromuscular transmission at the motor end plate.

Acute non-infective laryngitis

Laryngitis can occur after an episode of aggressive singing, shouting or screaming. The cords are reddened, mild oedema may be present, and submucosal haemorrhages may occur. Treatment is directed at allowing the acute inflammation to resolve and correction of underlying poor vocal habits.

Vocal cord nodules

Nodules are more common in male children and adult women, particularly in personalities who vocalize aggressively.

The nodule is located at the junction of the anterior and middle third of the vocal cord (Fig. 3.16). This is the area of maximum trauma at higher pitch levels seen in activities such as screaming and singing. The dysphonia is breathy and husky with a low pitch quality due to the mass loading of the vocal cords.

Fig. 3.16 Vocal cord nodules.

With suitable voice therapy at reducing stress and improving vocal production, the majority of vocal cord nodules either resolve or are greatly improved. Only rarely is microlaryngoscopic excision required.

Vocal cord oedema and polyps

Oedema of the vocal cords is usually symmetrical and affects the whole length of the cord. It is due to accumulation of fluid in the subepithelial space of Reinke and is called Reinke’s oedema. Localization of the oedema to a circumscribed site will produce a polyp, usually sited in the anterior third of the vocal cord. Smoking is thought to be the principal risk factor for Reinke’s oedema owing to its effects on collagen synthesis and the microvascular circulation. Laryngopharyngeal reflux and hypothyroidism are the other risk factors.

Mild oedema of the cords may resolve with improvement in the voice. More severe forms, such as Reinke’s, are best treated by microsurgical removal of oedematous tissue, preserving the overlying mucosa (Fig. 3.17). Tissue should always be sent for histological diagnosis.

Fig. 3.17 Reinke’s oedema causing swelling of both vocal cords. There is also a vocal cord polyp in the subglottis anteriorly.

Chronic non-infective laryngitis

Epithelial changes in the vocal cords can occur owing to chronic vocal abuse coupled with irritant effects of long-term alcohol and tobacco use. The voice is described as a ‘gin and midnight voice’. The changes may be reversible with vocal therapy and alteration of life habits, but most patients will require surgical removal of the hyperplastic epithelium. Dysplasia or even frank neoplasia can occur in chronic hyperplastic laryngitis.

Contact ulcers

Vocal abuse due to hyperadduction of the vocal folds may result in erosion of surface mucosa; particularly susceptible is the junction of the middle and posterior third of the vocal cord (Fig. 3.18). These are termed contact ulcers and can be sited at the vocal process of the arytenoids. The reaction can sometimes lead to considerable granulation tissue with the formation of a contact granuloma (Fig. 3.19). Gastro-oesophageal reflux may exacerbate or perpetuate this problem.

Fig. 3.18 Contact ulcer on vocal process of left arytenoid.

Fig. 3.19 Vocal cord granuloma (x) arising from the vocal process of the left arytenoid cartilage.

A unilateral ulcer will require biopsy to exclude neoplasia. Bilateral cases without marked granulation may resolve with a combination of voice therapy, antibiotics, antireflux treatment and a reducing course of oral steroids. Surgical excision followed by medical treatment is rarely necessary.

Musculoskeletal tension disorders

Tension in individuals can be due to exogenous sources, e.g. overwork, worries or family life. Endogenous causes of tension include features such as overambition, perfectionism and uncontrollable anger. Such stresses may produce contraction of the intrinsic and extrinsic muscles of the larynx. This hypertonicity results in an audible and normal voice disorder, laryngoscopic examination.

The cardinal features are a dysphonia and the presence of discomfort or pain around the larynx. The clinician can reproduce the pain by palpating the larynx (Fig. 3.21). Occasionally patients may complain of feeling a foreign body in the throat and difficulty in swallowing.

Fig. 3.21 Laryngeal signs present in patients suffering with dysphonia secondary to musculoskeletal tension disorders.

The diagnosis is confirmed by an improvement in the voice if the larynx is massaged. Usually, counselling to reduce the causes of stress leads to rapid resolution of symptoms.

Ventricular dysphonia (dysphonia plicae ventricularis)

Ventricular dysphonia is a voice disorder that results from utilizing the false cords to produce vibration. It is usually seen in tense individuals. However, patients with lesions of the true cords may compensate by vocalizing with the false cords. The voice is harsh and frequently low pitched as if the patient is being strangled. Speech therapy is helpful in management.

Suitable speech therapy directed at muscular relaxation and correct vocalization produces good results.

Conversion voice disorders (hysterical voice disorder)

A conversion reaction is the production of physical symptoms without any underlying pathophysiological disease. If the larynx is chosen as the vehicle for the conversion reaction it can result in muteness, aphonia or dysphonia. A diagnosis of a conversion voice disorder can only be made if the larynx is normal in structure and function. In the majority of cases the conversion voice disorder is associated with a major emotional conflict or stress. The voice symptoms enable the patient to avoid emotional anguish.

The basis of treatment is to uncover the causes of the stress and assist the patient in coping with the events. Retrieval of the voice must be rapid, otherwise the risk of the conversion being resistant to therapy is high.

Mutational falsetto (puberphonia)

Mutational falsetto is the failure to change from a preadolescent high-pitched voice to the lower pitched voice of male adulthood. It is rarely due to immaturity of the larynx or vocal cords. Occasionally, chronic disorders, e.g. severe childhood asthma, may prevent or retard laryngeal development. In the majority of cases of puberphonia, the larynx is anatomically and physiologically normal.

The voice is characteristically high pitched, weak, breathy and monotonous and female in quality. It sounds immature and inadequately assertive. However, in sudden vocal outbursts, e.g. coughing or laughing, the voice may drop in pitch. Only a mature larynx can produce the low-pitched voice, enabling an aetiology of hypogonadism to be dismissed. Voice therapy usually produces a rapid resolution. In rare cases, long-term therapy is required to lower the fundamental speaking frequency.

Laryngeal papillomatosis

Laryngeal papillomata (Fig. 3.20) is a rare cause of dysphonia. It is caused by the human papilloma virus subtypes 6 and 11 and occasionally subtype 16 or 18. The virus is usually acquired in utero through an ascending infection through the mother’s cervix.

Fig. 3.20 Extreme laryngeal papillomatosis occluding the airway and obscuring the laryngeal inlet.

Symptoms range from none to dysphonia to dyspnoea with or without stridor. Treatment is aimed at inducing a remission. Human papilloma vaccination programmes do not include subtypes 6 and 11, so surgery is indicated in symptomatic individuals.

Laryngotracheobronchitis

Laryngotracheobronchitis is a viral infection, usually of the parainfluenza or respiratory syncytial type, occurring mostly between the ages of 6 months and 3 years. Clinical features include:

The airway problems are caused by the presence of tenacious secretions and mucosal swelling in the subglottis with risk of impaction of plugs of mucus.

Hospitalization is advisable in all except the mildest cases. The child is nursed in a croupette with humidified and warmed air to loosen thick secretions. Oxygen is administered to correct hypoxia. Nebulized or systemic steroids may be helpful.

Intubation is required in progressive and severe cases. Tracheostomy is reserved for airways that cannot be intubated. Regular saline suction and physiotherapy are performed postoperatively. In most cases, endotracheal intubation should only be necessary for 2–5 days.

Supraglottitis

Supraglottitis (acute epiglottitis) is caused by group B Haemophilus influenzae and is characterized by gross swelling in the supraglottis (Fig. 3.22). It is seen primarily in 3–7-year-olds, although adults may also be affected. Clinical features include:

Fig. 3.22 Supraglottitis. Diagnosis is clinical and the priority is to secure the airway. Physical examination of the throat may induce respiratory arrest and should be avoided unless facilities for immediate intubation or tracheostomy are available.

Supraglottitis is an emergency, as the time interval from stridor to total respiratory obstruction may be extremely short. Any distress to the child is to be avoided. Heliox and adrenaline (epinephrine) nebulizers may buy time until a senior anaesthetist and ENT surgeon are available. In most cases the anaesthetist is successful in intubating the child; however, the ENT surgeon is standing by to carry out an emergency tracheostomy if necessary. Intravenous third-generation cephalosporins are commenced and later changed depending on blood culture results. The patient is usually extubated a few days later when the condition has responded to treatment. Supraglottitis has become less common in children because of vaccination programmes.

Congenital tumours, webs and cysts

Subglottic haemangioma is the most common congenital tumour causing stridor. It is visualized on a lateral neck X-ray. The diagnosis is confirmed by endoscopy without biopsy. The condition is self-limiting as the tumours start to regress after the first year of life, but tracheostomy is occasionally necessary for airway obstruction. Laryngeal webs or cysts of any significant size may produce stridor, particularly if the airway is further compromised by an intercurrent infection.

Laryngomalacia (congenital laryngeal stridor)

Laryngomalacia is characterized by a weak supraglottic framework which collapses on inspiration, notably during exertion and crying. Severe stridor can supervene during respiratory infections. It is self-limiting and usually resolves by the age of 2 years. Surgery may be indicated if there is failure to thrive.

Subglottic stenosis

Subglottic stenosis may be congenital. Acquired cases are the result of the trauma of prolonged endotracheal intubation, particularly in premature births (Fig. 3.23). Clinical features include stridor on exertion, or with respiratory infection.

Fig. 3.23 Subglottic stenosis, seen here in a premature birth. The condition can be verified by a neck X-ray.

Tracheostomy may be necessary to secure the airway. The subglottis can be subsequently sized and decannulation attempted if the lumen enlarges satisfactorily with age. Laser excision or laryngeal reconstructive surgery may be required in severe cases.

Foreign body obstruction

Inhalation of foreign bodies is most common in children. In adults, the problem is usually associated with psychiatric illness or alcohol intoxication. Objects can lodge anywhere in the laryngotracheobronchial tree (Fig. 3.24), and may remain symptomless for long periods. Common symptoms include:

Fig. 3.24 Foreign body: chest X-ray in full expiration. A foreign body (peanut) lodged in the left main bronchus has produced ipsilateral hyperinflation and gross mediastinal shift to the right.

Foreign bodies can be radiolucent, so plain radiology may be misleading. Foreign bodies in the oesophagus can also produce stridor.

In a child, a foreign body may be dislodged by holding the patient up by the legs and giving a sharp slap on the back. The Heimlich manoeuvre can be used in both adults and children (Fig. 3.25). There should be a low threshold for tracheobronchoscopy in a child who has had a significant choking episode, even in the absence of clinical signs or radiological findings.

Fig. 3.25 The Heimlich manoeuvre: performed by applying a sudden bear hug, centred on the upper abdomen and xiphisternal region.

Retropharyngeal abscess

A now rare condition, retropharyngeal abscesses occur mostly in young infants and children. Inflammation and swelling in the retropharyngeal space, secondary to oropharyngeal infection, can cause respiratory embarrassment and severe dysphagia (Fig. 3.26). The child assists breathing by hyperextension of the neck, which is held rigid. Urgent parenteral antibiotics are administered and surgical drainage is performed to avoid spontaneous rupture with risk of inhalation of pus.

Fig. 3.26 Retropharyngeal abscess.

Respiratory papillomata

Respiratory papillomata are characterized by warty lesions appearing in the larynx caused by the human papilloma virus (Fig. 3.27). The trachea, bronchi and pharynx may be involved in florid cases. They are thought to be due to ascending uterine infection; however, acquired cases in adults may be due to genetic predisposition or be sexually acquired. Clinical features include stridor and hoarseness.

Fig. 3.27 Respiratory papillomata.

The carbon dioxide laser or sharp dissection under the microscope will minimize trauma to the underlying laryngeal mucosa.

If surgery needs to be repeated frequently for symptom control, then medical therapy, such as interferons, may be considered to try to induce remission. Tracheostomy is sometimes necessary in severe cases.

Acute laryngitis

Acute laryngitis results in marked inflammation of the vocal cords which can occur in respiratory infections or secondary to vocal abuse, tobacco smoke or ingestion of spirits. Clinical features include hoarseness and throat discomfort.

Treatment is symptomatic and includes voice rest, steam inhalation and avoidance of smoke and spirits.