Learning objectives:
Disorders affecting the neuromuscular junction (NMJ) are among the most interesting
and rewarding seen in the EMG laboratory. These disorders are generally pure motor
syndromes that usually preferentially affect proximal, bulbar, or extraocular muscles.
They are confused occasionally with myopathies. With knowledge of normal NMJ
physiology, most of the abnormalities affecting the NMJ can be differentiated using a
combination of nerve conduction studies, repetitive stimulation, exercise testing, and
needle EMG.