ABSTRACT
Electrodiagnostic studies should be used to confirm or clarify clinical findings of weakness or amyotrophy caused by myogenic or neurogenic etiologies. Electromyography (EMG) confirms axonal lesions of lower motor neurons, helps to define the lesion location and is specifically helpful in tunnel syndromes. Additionally, it can provide information on the level of damage and the degree of recovery, if present. EMGs also help detect physiological variations of the peripheral nerve innervations and test the neuromuscular junction. Nerve conduction velocity (NCV) tests provide information about the state of a peripheral nerve, including its motor and sensory nerve fibers. The obtained results give information about the kind and intensity of the nerve injury, as well as its location. Nerve conduction velocity tests provide information about the state of motor and sensory nerves’ sheath. Indirectly, the finding of a slow nerve conduction velocity helps to define the location of the nerve compression. This chapter will review both normal and abnormal findings of electrodiagnostic tests so the clinician can better understand the results and apply them to improve patient care.
