Pathophysiology
Clinical meaning
Advanced management of peripheral neuropathy requires distinguishing axonal from demyelinating patterns, length-dependent from non-length-dependent neuropathies, and identifying the underlying etiology among over 100 potential causes. Electrodiagnostic studies (nerve conduction velocity studies and electromyography) are the cornerstone of evaluation: axonal neuropathies show reduced amplitude with preserved conduction velocity, while demyelinating neuropathies show prolonged distal latencies, reduced conduction velocity, conduction block, and temporal dispersion. The NP must systematically evaluate metabolic (diabetes, B12, thyroid), toxic (alcohol, chemotherapy, heavy metals), inflammatory (CIDP, vasculitic neuropathy), infectious (HIV, Lyme, hepatitis C), hereditary (CMT), and paraneoplastic etiologies through targeted laboratory and electrodiagnostic testing.