Dysphonia is a disorder of the volume, pitch or quality of the voice resulting from dysfunction of the larynx, i.e., a disorder of phonation or sound generation. Hence this is a motor speech disorder and could be considered as a dysarthria if of neurological origin.
Dysphonia manifests as hoarseness, or a whispering breathy quality to the voice. Diplophonia may occur. At the extreme, there may be complete loss of the voice (aphonia).
Recognized causes of dysphonia include:
- Infection (laryngitis)
- Structural abnormalities, e.g., polyp, nodule, papilloma of vocal cord
- Neurological causes:
- Focal dystonic syndrome: spasmodic dysphonia or laryngeal dystonia (either abductor or adductor); the voice may have a strained and harsh quality, with low volume and pitch, vocal tremor, and irregularly distributed stoppages; with continuing speech, or if holding a single note, the voice may fade away entirely. These syndromes may be amenable to treatment with botulinum toxin.
- Flaccid dysphonia, due to superior laryngeal nerve or vagus nerve (recurrent laryngeal nerve) palsy, bulbar palsy.
Whurr R, Lorch M, Fontana H, Brookes G, Lees A, Marsden CD. The use of botulinum toxin in the treatment of adductor spasmodic dysphonia. Journal of Neurology, Neurosurgery and Psychiatry 1993; 56: 526-530 Cross ReferencesAphonia; Bulbar palsy; Diplophonia; Dysarthria; Dystonia; Hypophonia; Vocal tremor, Voice tremor