Electrodiagnostic Evaluation of Brachial Plexopathies

J Korean Assoc EMG Electrodiagn Med 2002;4(1):1-7.
Published online May 10, 2002.

Abstract

The brachial plexus is a large, vulnerable peripheral nervous system structure, which is diffucult to assess electrophysiologically because of its proximal location and its complexty. Almost all brachial plexopathies cause either axon loss or, less commonly, combinations of axon loss and demyelinating conduction block. The axon loss will affect the amplitudes of motor and sensory nerve conduction studies on distal stimulation, as well as causing positive sharp waves and fibrillation potentials and motor unit potential dropout on needle electorde examination. To adequately assess the brachial plexopathies, a thorough taking of history and a physical examination should be done prior to electrodiagnostic study. In the electrodiagnosis, extensive nerve conduction studes including “uncommon” nerves should be performed in combination of an extensive needle electrode examination.

Key Words: Brachial Plexopathy, Electordiagnositic medicine, Nerve conduction studies, Axons