Dysphonia
Encyclopedia
Dysphonia is the medical term for disorders of the voice: an impairment in the ability to produce voice sounds using the vocal organs (it is distinct from dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...

 which means disorders of speech, that is, an impairment in the ability to produce spoken words). Thus, dysphonia is a phonation
Phonation
Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...

 disorder. The dysphonic voice can be hoarse or excessively breathy, harsh, or rough, but some kind of phonation is still possible (contrasted with the more severe aphonia
Aphonia
Aphonia is the inability to speak. It is considered more severe than dysphonia. A primary cause of aphonia is bilateral disruption of the recurrent laryngeal nerve, which supplies nearly all the muscles in the larynx...

 where phonation is impossible).

Dysphonia has either organic or functional causes due to impairment of any one of the vocal organs. However, typically it is caused by some kind of interruption of the ability of the vocal folds
Vocal folds
The vocal folds, also known commonly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx...

 to vibrate normally during exhalation
Exhalation
Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....

. Thus, it is most often observed in the production of vowel
Vowel
In phonetics, a vowel is a sound in spoken language, such as English ah! or oh! , pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis. This contrasts with consonants, such as English sh! , where there is a constriction or closure at some...

 sounds. For example, during typical normal phonation
Phonation
Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...

, the vocal folds
Vocal folds
The vocal folds, also known commonly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx...

 come together to vibrate in a simple open/closed cycle modulating the airflow from the lungs. Weakness (paresis
Paresis
Paresis is a condition typified by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it also can be used to describe the muscles of the eyes , the stomach , and also the vocal cords...

) of one side of the larynx
Larynx
The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...

 can prevent simple cyclic vibration and lead to irregular movement in one or both sides of the glottis
Glottis
The glottis is defined as the combination of the vocal folds and the space in between the folds .-Function:...

. This irregular motion is heard as roughness. This is quite common in vocal fold paresis
Vocal cord paresis
Vocal cord paresis is weakness of one or both vocal folds. Symptoms of paresis include hoarseness; vocal fatigue; mild to severe reduction in vocal volume; pain in the throat when speaking; shortness of breath; aspiration with frequent resultant coughing, and in extreme cases may cause death...

.

Common types of dysphonia

  • Organic dysphonia
    • Laryngitis (Acute: viral / bacterial) - (Chronic: smoking / GERD / LPR (Laryngopharyngeal Reflux) ).
    • Neoplasm (Premalignant: dysplasia) - (Malignant: Squamous cell carcinoma).
    • Trauma (Iatrogenic: surgery / intubation) - (Accidental: blunt / penetrating / thermal).
    • Endocrine (Hypothyroidism / hypogonadism).
    • Haematological (Amyloidosis).
    • Iatrogenic (inhaled corticosteroids)

  • Functional dysphonia
    • Psychogenic
    • Vocal misuse
    • Idiopathic

Associated conditions (incomplete list)

  • Voice disorders
    • Laryngitis
      Laryngitis
      Laryngitis is an inflammation of the larynx. It causes hoarse voice or the complete loss of the voice because of irritation to the vocal folds . Dysphonia is the medical term for a vocal disorder, of which laryngitis is one cause....

    • Chorditis
      Chorditis
      Chorditis is the inflammation of vocal cords usually as a result of voice abuse but sometimes because of cancer....

    • Vocal cord nodules
    • Vocal fold cyst
      Vocal fold cyst
      Vocal fold cysts are collections of fluid in sac-like formations on the vocal folds.Cysts can deteriorate the quality of human speech production, causing diplophonia, a condition where the vocal cords produce multiple tones at the same time, or dysphonia, an impaired quality of voice typically...

    • Reinke's Edema
      Reinke's Edema
      Reinke's edema, also known as polypoid degeneration, is the swelling of the vocal folds due to fluid collection .-Presentation:Reinke's edema causes the vocal folds to bilaterally swell giving them an uneven, sac-like appearance...

       (Mostly caused by smoking)
    • Laryngeal papillomatosis
      Laryngeal papillomatosis
      Laryngeal papillomatosis, also known as recurrent respiratory papillomatosis or glottal papillomatosis, is a rare medical condition , caused by a HPV infection of the throat. Laryngeal papillomatosis causes assorted tumors or papillomas to develop over a period of time...

  • Gastroesophageal reflux disease
    Gastroesophageal reflux disease
    Gastroesophageal reflux disease , gastro-oesophageal reflux disease , gastric reflux disease, or acid reflux disease is chronic symptoms or mucosal damage caused by stomach acid coming up from the stomach into the esophagus...

    : When there is a clinical suspicion for GERD as the cause of the dysphonia, an Esophageal pH Monitoring
    Esophageal pH Monitoring
    Esophageal pH monitoring is the current gold standard for diagnosis of gastroesophageal reflux disease . It provides direct physiologic measurement of acid in the esophagus and is the most objective method to document reflux disease, assess the severity of the disease and monitor the response of...

     is required to confirm the diagnosis and establish the relationship between GERD and dysphonia.

  • Laryngeal cancer
    Cancer of the larynx
    Laryngeal cancer may also be called cancer of the larynx or laryngeal carcinoma. Most laryngeal cancers are squamous cell carcinomas, reflecting their origin from the squamous cells which form the majority of the laryngeal epithelium....

  • Myasthenia gravis
    Myasthenia gravis
    Myasthenia gravis is an autoimmune neuromuscular disease leading to fluctuating muscle weakness and fatiguability...

  • Hypothyroidism
    Hypothyroidism
    Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

  • Hyperthyroidism
    Hyperthyroidism
    Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...

  • Sinusitis
    Sinusitis
    Sinusitis is inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days...

  • Lung cancer
    Lung cancer
    Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...

  • Juvenile dermatomyositis
    Juvenile dermatomyositis
    Juvenile dermatomyositis is an autoimmune disease causing vasculitis that manifests itself in children; it is the pediatric counterpart of dermatomyositis. In JDMS, the body's immune system attacks blood vessels throughout the body, causing inflammation called vasculitis...

  • Parkinson's disease
    Parkinson's disease
    Parkinson's disease is a degenerative disorder of the central nervous system...

  • Botulinum toxin
    Botulinum toxin
    Botulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...


Clinical measurement

Dysphonia is measured using a variety of examination tools that allow the clinician to see the pattern of vibration of the vocal folds
Vocal folds
The vocal folds, also known commonly as vocal cords, are composed of twin infoldings of mucous membrane stretched horizontally across the larynx...

, principally laryngeal videostroboscopy. Acoustic
Acoustics
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...

 examination is also common, obtained by recording the sounds made during sustained phonation
Phonation
Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...

 or whilst speaking. Another tool is electroglottograph
Electroglottograph
The electroglottograph, or EGG, is a device for the noninvasive measurement of the time variation of the degree of contact between the vibrating vocal folds during voice production...

y.

Subjective measurement of the severity of dysphonia is carried out by trained clinical staff. The GRBAS (Grade, Roughness, Breathiness, Asthenia, Strain) scale or the Oates Perceptual Profile are widely used for this purpose. Objective measurement of the severity of dysphonia typically requires signal processing algorithms applied to acoustic or electroglottographic recordings. These include algorithms such as jitter, shimmer and noise-to-harmonics ratios, but these have been shown to have some critical limitations, particularly for severe dysphonia. Recent advances in signal processing theory have led to more robust algorithms.

When should a patient seek treatment?

Any person who has been hoarse for four weeks or more should seek medical attention from their family doctor. They may require to be seen by an ear, nose and throat specialist for further examination including inspection of the larynx. This can be done quite easily (by the specialist) using an angled mirror, or flexible fibre-optic 'telescope'.
Persistent hoarseness, difficulty in swallowing, sore throat, choking when swallowing (especially fluids), persistent earache, coughing up blood, weight loss and loss of appetite may indicate a more serious condition and should always be taken seriously.

How is dysphonia treated?

Each condition has its own specific treatment, and the treatment should also be tailor-made to each individual. The general principles of management are described below.
Conservative therapy
Every attempt should be made to identify and eliminate causative factors such as stress, smoking, and alcohol. Drink plenty of clear fluid to avoid a dry throat. Rest the voice completely for two to three days. No talking or whispering is allowed. Communicate to others by writing everything down on a note pad.
Speech therapy
The speech therapist plays an important role in the assessment and treatment of patients with voice disorders, eg Reinke’s oedema, vocal cord nodules and voice misuse. The therapy will take some weeks or months before any improvements are noticed and so the patient must be highly motivated.
Medical therapy
Upper respiratory tract infections, eg acute laryngitis, are commonly caused by viral infections. Bed rest, regular paracetamol and saline or soluble aspirin gargles are often adequate.
Antibiotics are only indicated when there is bacterial infection. Nasal sprays such as Beconase are used to treat patients who suffer from chronic inflammation of the sinuses and nasal lining and who get catarrh dripping down the back of the throat. Medications to reduce acid secretion by the stomach are used to treat patients with gastro-oesophageal reflux.
Surgery
Surgery is indicated for diagnosis (eg tissue biopsies) and treatment (eg removal of tumours and laser surgery). The operation is performed with a fibre-optic viewing ‘telescope’ (endoscope) under general anaesthesia.
The view of the larynx is magnified with a microscope so that delicate operations can be carried out. The procedure is known as ‘microlaryngoscopy’ or ‘endolaryngeal microsurgery’.
Surgical management of non-cancerous causes of voice disorders is only indicated when all the other measures have failed.

See also

  • National Center for Voice and Speech
    National Center for Voice and Speech
    The National Center for Voice and Speech , is a multi-site research and teaching organization dedicated to studying the characteristics, limitations and enhancement of human voice and speech. The NCVS is located in Salt Lake City, Utah with the Lead Institution located at the University of Utah...

  • Human Voice
    Human voice
    The human voice consists of sound made by a human being using the vocal folds for talking, singing, laughing, crying, screaming, etc. Its frequency ranges from about 60 to 7000 Hz. The human voice is specifically that part of human sound production in which the vocal folds are the primary...

  • Vocology
    Vocology
    Vocology is the science of enabling or endowing the human voice with greater ability or fitness.. Its concerns include the nature of speech and language pathology, the defects of the vocal tract , the remediation of speech therapy and the voice training and voice pedagogy of song and speech for...

  • Otorhinolaryngology#Laryngology

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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