Voice Disorders: Functional and Organic Dysphonia

Definition and EtiologyTop

Dysphonia is the impaired ability to produce voice sounds. This is distinct from dysarthria, which is the impaired movement of muscles to produce speech, including the lips, tongue, vocal cords, and diaphragm. Dysphonia is subdivided into categories based on the presence or absence of an identifiable etiology, namely, organic versus functional dysphonia. Dysphonia can be assessed and described by the GRBAS system, which is a voice-rating scale. GRBAS is an auditory-perceptual evaluation of voice, which grades the degree of hoarseness based on roughness, breathiness, asthenia, and strain using a 0 to 3 scoring system, with 0 being normal and 3 being a high degree of dysfunction.

Functional Dysphonia Top

Functional dysphonia is diagnosed when no anatomical or organic cause can explain voice dysfunction. Functional dysphonia may be classified as one of the following:

1) Psychogenic dysphonia: Impaired voice due to a psychogenic rather than a physical origin. It is generally associated with anxiety. Psychogenic dysphonia may be a result of excessive laryngeal muscle tension to provide glottis closure.

2) Vocal cord misuse: This is caused by vocal overuse.

3) Idiopathic vocal cord dysfunction: A paradoxical adduction of the vocal folds during inspiration, causing dyspnea.

Treatment

Depending on etiology, treatment involves a combination of speech therapy, psychotherapy therapy, behavioral therapy, and hypnosis.

Organic Dysphonia Top

Organic dysphonia includes several organic and anatomic pathologies. Given the vast differential diagnosis, organic dysphonia can be organized by system:

1) Vascular: Hemangiomas, arteriovenous malformation, lymphatic malformation.

2) Infectious: Laryngitis (viral, bacterial, and fungal).

3) Trauma/toxin: Arytenoid dislocation, neck trauma, caustic inhalation injury, laryngopharyngeal reflux.

4) Autoimmune: Connective tissue disorder (rheumatoid arthritis, systemic lupus erythematosus).

5) Malignancy: Laryngeal carcinoma (squamous cell carcinoma).

6) Iatrogenic: Postintubation neuropraxia; thyroid surgery; anterior cervical disc surgery; cardiothoracic, vascular, and neurologic procedures.

7) Neoplasm: Recurrent respiratory papillomatosis; benign laryngeal lesions (nodules, cysts, polyps); neoplasms of the skull base, mediastinum, esophagus, lung, and thyroid.

8) Neurologic: Stroke, myasthenia gravis, Parkinson disease.

9) Endocrine: Hypothyroidism (laryngeal myxedema).

10) Congenital: Congenital webs.

Diagnosis

Otolaryngology consultation is necessary. Diagnosis is based on nasolaryngoscopy for visualization or videostroboscopy for revealing mucosal wave abnormalities.

Ancillary Tests

Acoustic analysis, speech aerodynamic study, laryngeal electromyography, computed tomography (CT)/magnetic resonance imaging (MRI).

Treatment

Treat the underlying cause when discovered. Medical treatment rarely leads to resolution of symptoms; surgical treatment and voice therapy are generally more appropriate. Guidelines from the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) suggest the following:

1) Recommend against prescribing antireflux medications without signs of acid reflux.

2) As an option, you may prescribe antireflux medications for hoarseness with signs of chronic laryngitis.

3) Recommend against prescribing routine oral glucocorticoids.

4) Recommend against prescribing routine antibiotics.

5) Perform laryngoscopy before suggesting voice therapy and speech language pathology.

6) Recommend surgery for laryngeal malignancy, benign lesions, or glottis insufficiency.

7) Educate patients on control and preventative measures.