The voice is produced by hyperadduction of the true and often the false cords. In addition the extrinsic muscles of the larynx contract and elevate the larynx in synchrony with the spasms. It is controversial whether the origin is psychogenic or neurologic in origin. Perhaps conversion reaction and musculoskeletal tension account for some cases and a localized neurologic dystonia account for others. These are considered extrapyramidal diseases.
Onset is in the fifth through sixth decades, usually associated with emotional stress.
Regardless of the cause, serious occupational, social, and emotional disturbances are sequelae of this disorder. B. Abductor spastic dysphonia is a term that describes the abrupt breathy releases of air owing to sudden hyperabduction of the vocal folds. The spasms occur during the production of unvoiced consonants, and rarely occur during vowel phonation. The onset is gradual, and often associated with emotional distress. Laryngeal Surgery - Phonosurgery A. Vocal Fold Injections 1.