[Electromyographic study of psychogenic dysphonias]

Psychogenic dysphonia traditionally has been considered a case of dystonia in which the functional disturbance is attributed to a disturbance in the synchronization of the laryngeal abductor and adductor muscles. Five patients with psychogenic dysphonia were studied by telelaryngoscopy and conventional laryngeal electromyography. This excluded the neuromuscular origin of the damage and confirmed the diagnosis. A complete glottic gap was present during phonation at the beginning of the exploration, but at the end of the examination, direct laryngoscopy revealed complete glottic closure with normal phonation. Laryngeal electromyography showed no abnormalities suggestive of a neuromuscular origin. In every case, the effort patterns of motor unit potentials were normal and denervation activity was absent in resting conditions.