SENSORY NERVE-FIBERS FROM LUMBAR INTERVERTEBRAL DISCS PASS THROUGH RAMI COMMUNICANTES - A POSSIBLE PATHWAY FOR DISCOGENIC LOW-BACK-PAIN

It has been thought that lumbar intervertebral discs were innervated s egmentally. We have previously shown that the L5-L6 intervertebral dis c in the rat is innervated bilaterally from the L1 and L2 dorsal root ganglia through the paravertebral sympathetic trunks, but the pathways between the disc and the paravertebral sympathetic trunks were unknow n. We have now studied the spines of 17 rats to elucidate the exact pa thways. We examined serial sections of the lumbar spine using immunohi stochemistry for calcitonin gene-related peptide, a sensory nerve mark er. We showed that these nerve fibres from the intervertebral disc ran through the sinuvertebral nerve into the rami communicantes, not into the corresponding segmental spinal nerve. In the rat, sensory informa tion from the lumbar intervertebral discs is conducted through rami co mmunicantes. If this innervation pattern applies to man, simple decomp ression of the corresponding nerve root will not relieve discogenic pa in. Anterior interbody fusion, with the denervation of rami communican tes, may be effective for such low back pain.