Major patterns of laryngeal electromyography and their clinical application.

Laryngeal electromyography (LEMG) is clinically valuable in the evaluation of laryngeal dysfunction and vocal fold immobility. To facilitate clinical application of this electrophysiologic test, a detailed description of modified LEMG techniques is presented. The techniques were applied for simultaneous bilateral recordings of the thyroarytenoid, cricothyroid, and posterior cricoarytenoid muscles. The basic patterns of LEMG are classified into three different types: normal, neuropathy, and myopathy. In an attempt to characterize these patterns, we have reported eight LEMG-documented cases: unilateral laryngeal paralysis, bilateral laryngeal paralysis, cricoarytenoid joint dislocation, cricoarytenoid joint ankylosis, laryngeal myopathy, pharyngeal paralysis (soft palate paralysis), spasmodic dysphonia, and unilateral laryngeal paralysis with anastomosis. The significance of the major LEMG patterns is discussed.