Hoarseness

Synonym: dysphonia

Hoarseness is a subjective term, and usually refers to a weak or altered voice. Dysphonia is similar, but may also mean difficulty making sounds. Some terms which may be used to describe a voice change are: breathy, harsh, tremulous, weak, reduced to a whisper, or vocal fatigue (meaning voice deteriorates with use).¹

In Western societies, about one third of the workforce need their voice for work. In UK, about 50,000 patients per year are referred to ENT departments with voice problems.

Risk factors for voice problems

• Smoking (also the main risk factor for laryngeal carcinoma)
• Excess alcohol consumption
• Gastro-oesophageal reflux
• Professional voice use, e.g. teachers, actors and singers
• Environment: poor acoustics, atmospheric irritants and low humidity

Sound is produced in the larynx by vibration of the vocal cords. Resonance occurs in the pharynx, nose and mouth; articulation uses the mouth and tongue. Coughing requires adduction of the vocal cords to be effective.

Innervation of the laryngeal muscles is from the vagus nerve via its branches, the superior laryngeal and recurrent laryngeal nerves. The recurrent laryngeal nerve controls abduction and adduction of the vocal cords. This nerve has a long course, from base of skull to mediastinum: on the left side it loops under the aortic arch and on the right under the subclavian artery.

The vocal cords are subject to high forces and so may be affected by voice overuse or misuse.

Voice problems are often multifactorial and due to voice overuse. Serious pathology must be excluded, particularly laryngeal carcinoma and other tumours (head, neck or chest) causing laryngeal nerve palsy.⁴ Children also need assessment, as laryngeal papillomas may need treating, or rarely, there may be an underlying malignancy.⁵

Causes of hoarseness

Infections:

• Acute laryngitis, often with upper respiratory infection; usually viral, possibly secondary infection with staphylococci or streptococci
• Other infections: fungal or TB; may be immunosuppressed

Benign laryngeal conditions (for details see last section):

• Voice overuse
• Benign lesions of the vocal cords: nodules (singer's nodes) and other lesion are common
• Functional dysphonias

Malignancy:

• Carcinoma of the larynx
• Other head, neck or chest tumours, e.g. lung cancer, lymphoma, thyroid cancer

Neurological:

• Laryngeal nerve palsy (see below): this has various causes including lung cancer, other tumours and thoracic aortic aneurism
• Stroke and other focal brain lesions
• Parkinson's disease
• Motor neurone disease
• Essential tremor
• Myasthenia gravis

Systemic:

• Endocrine: hypothyroidism, acromegaly
• Rheumatoid arthritis affecting the cricoarytenoid joints²
• Granulomatous disease, e.g. sarcoid, Wegener's, syphilis, TB

Causes in children:⁵

• Congenital, e.g. glottic web, congenital vocal cord paralysis, congenital cyst
• Older children: vocal cord nodules, voice overuse, gastro-oesophageal reflux, papillomas (as for adults)
• Very rarely, malignancy

Contributing factors:

• Drying of the laryngeal mucosa, e.g. from low humidity, nasal obstruction, smoking, air pollution or medication e.g. antihistamines, inhaled steroids, anticholinergics
• Voice overuse (see below)
• Gastro-oesophageal reflux (reflux laryngitis)
• Scarring, e.g. after prolonged intubation or treatment of carcinoma⁵
• Age-related loss of pliability (normal ageing of the voice)⁵

History¹

• Symptoms: duration; check patient's meaning of 'hoarseness'
• Occupation, normal pattern of voice use and any recent change such as singing or shouting
• Smoking, alcohol
• Reflux symptoms such as acid taste in mouth in the morning, throat clearing, cough or 'choking' sensation, sensation of lump in the throat⁶
• Dysphagia or aspiration
• Nasal blockage

Clinical features¹

• Signs of airway obstruction - see emergency section above
• Systemic features - e.g. hypothyroidism, tremor
• Signs of infection - systemic signs; localised tenderness suggests bacterial infection or abscess
• Laryngeal function - listen to patient's voice, assess cough and swallowing
• Features of malignancy - weight loss, dysphagia, cervical nodes, chest examination

Initial investigations:

• Inspection of the larynx for any patient with hoarseness for > 3 weeks
• General investigations may be appropriate, e.g. thyroid function and chest x-ray

Investigations available in voice clinics or ENT departments include:⁴

• Indirect laryngoscopy
• Fibreoptic laryngoscopy, which does not require general anaesthetic, so enables examination of the larynx while using the voice
• Stroboscopy (videolaryngostroboscopy) uses fibre-optic images in slow motion to provide pictures of the working larynx
• Voice pathologists use other techniques to measure aspects of voice production, such as amplitude, pitch, range and aerodynamic efficiency

• Assessment at a voice clinic, for an accurate diagnosis.
• Professional voice users should be referred early.
• A multidisciplinary approach: voice therapists are an integral part of the team.
  • Voice therapy (a branch of speech therapy) is used in treating most voice disorders.⁸ It includes: education about voice production and 'vocal hygiene' (see prevention section); and help with voice production and relaxation.
• Surgical techniques involving microlaryngeal surgery.⁵

'Vocal hygiene' involves:

• Avoiding cigarette smoke, dust and fumes
• Controlling gastro-oesophageal reflux
• Maintaining hydration
• Recognising early warning signs of voice problems, such as: an unintentional change in pitch, voice fatigue (voice gets weaker with increasing use) and sore throat not due to infection

Prevention programmes have been found to be effective,³ though a Cochrane review did not confirm this.⁹

Laryngeal nerve palsy or vocal cord paralysis¹

This may cause a "breathy" voice, an inefficient cough or airway narrowing. The clinical features depend on whether one or both cords are affected, and the position of the cords - whether abducted or adducted. 'Semon's law' suggests that an incomplete paralysis of the recurrent laryngeal nerve affects the abductor muscles first, so that the vocal cord is in the midline. Complete paralysis affects the adductor muscles also, so the cord is fixed midway, in the paramedian position.

Surgical techniques such as Teflon injection or implants, combined with voice therapy, can restore function.

Benign lesions of the vocal cords

Vocal cord nodules (nodes or singer's nodes)¹

These are epithelial thickenings of the vocal cord, similar to callouses; often due to voice overuse. Voice therapy is the main treatment; surgery is occasionally needed.

Polyps of the vocal folds¹⁰

These are often unilateral - unlike nodules, which are generally bilateral. They may need excision to exclude malignancy, or if they do not resolve.

Papillomas of the larynx¹

They are epithelial lesions caused by the human papilloma virus (HPV). If untreated and large, they may cause airway obstruction. Invasive carcinoma can occur rarely. They are usually treated surgically. although newer techniques are being developed.¹¹

Reinke's oedema¹⁰

This is oedema of the vocal folds, which tends to give a deep, hoarse voice. It is usually linked to smoking plus voice overuse. Smoking cessation and voice therapy may help; surgery has also been used.

Voice overuse or misuse³

This is a common problem in some occupations such as acting and teaching; it may also follow unaccustomed voice use, such as shouting at a football match. Vocal strain may be exacerbated when attempting to compensate for an acute respiratory infection.

Benign lesions such as nodules ('singer's nodules'), cysts, haemorrhages and varices can occur with voice overuse. Management involves:

• Exclude other pathology.
• An accurate diagnosis (see investigations) - fibreoptic laryngoscopy and stroboscopic techniques are useful.
• A specific programme tailored to the observed pathology can then be devised. Prescribing rest alone may not be effective.
• Persistent nodules can be excised.

Functional dysphonia^7,12

This is a diagnosis of exclusion, where there is neither a structural abnormality of the larynx, nor cord paralysis.⁷ There are various types. Possible treatments are voice therapy, biofeedback, relaxation or cognitive-behavioural approaches. Treating contributing factors such as gastric reflux may help.¹³

Muscle tension dysphonia¹

There is an increase in tension in the laryngeal muscles, resulting in strain on muscles and voice. Common symptoms are vocal fatigue (voice becoming worse with use) and laryngeal discomfort. There may be various interacting causes, such as heavy demands on the voice, poor vocal technique and stress. Voice therapy is the main treatment.

Spasmodic dysphonia

This is a type of functional dysphonia, which is thought to be a focal dystonia of the laryngeal muscles. There is inappropriate spasm of the vocal folds during phonation.⁵ It can be treated with botulinum toxin injection.¹⁴

Gastro-oesophageal reflux (reflux laryngitis)^6,15

• This can lead to inflammation of the laryngeal mucosa, making the tissues more susceptible to trauma such as voice overuse. Relevant factors may be night-time reflux and high intra-abdominal pressure during singing.
• Patients may not have heartburn;¹³ see assessment section for symptoms of reflux laryngitis.
• Standard anti-reflux treatments such as PPIs and raising the head of the bed are suggested.