Electrodiagnosis in neuromuscular disorders

Nerve conduction and stimulation studies and needle electromyography are useful in objectively verifying the presence of disease of nerve and muscle. How pathologic alterations in muscle and nerve produce the electrical abnormalities detected by these combined techniques is explored to guide the clinician in distinguishing whether a neuromuscular disorder involves the motor neuron, peripheral nerve axon or myelin, neuromuscular synapse, or muscle; whether the problem is focal or generalized; and whether there is evidence of ongoing disease or repair.