Laryngismus fugax: transient laryngeal spasm secondary to brain stem ischemia.

Bilateral vocal cord immobility in adduction is an uncommon, yet potentially life threatening, disorder. Endolaryngeal and neuromuscular causes are well known and for the most part readily diagnosed by the otolaryngologist. Central neurologic etiologies are more unusual. A case of transient spastic laryngeal paralysis secondary to cardiac emboli and brain stem ischemia is presented. A mechanistic analysis suggests that this entity occurs in the setting of pseudobulbar paralysis, and that the ultimate ischemic event may be loss of glycine mediated inhibition of laryngeal motoneurons.