Laryngeal electromyography.

Laryngeal electromyography (LEMG) evaluates the integrity of the neuromuscular system in the larynx by recording action potentials generated in the laryngeal muscles during voluntary and involuntary contraction. LEMG is particularly useful for helping to differentiate between disorders involving upper motor neurons, lower motor neurons, peripheral nerves, the neuromuscular junction, muscle fibers, and the laryngeal cartilages and joints. LEMG should be considered to be an extension of the physical examination, not an isolated laboratory procedure. A careful history and laryngeal evaluation determine the indication for LEMG and which muscles or muscle groups, in particular, are to be studied. Abnormalities detected by LEMG are always interpreted within the context of the clinical picture.