Pathologic Basis of Lumbar Radicular Pain

BACKGROUND: Lumbar radicular pain is one of the most commonly encountered clinical syndromes; however, its underlying mechanistic basis, and its relation to the natural history of the disease, are poorly understood. METHODS: We revieved the available literature to explore the pathophysiology and natural history of lumbar radicular pain. RESULTS: Experimental observations have spawned distinctive, but not wally exclusive, pathophysiologic descriptions of radicular pain. These mechanisms include mechanical compression and inflammatory processes. In most cases, a complex interplay between these mechanisms is required to sustain the pain. However, when the dorsal root ganglion is mechanically deformed, sustained discharges causing pain can be evoked, leading to pain based on a purely mechanical basis. However, in other instances, previous sensitization of the nerve root by inflammatory processes is required. CONCLUSION: An understanding of these processes and the natural history of syndrome is important to developing therapeutic strategies.