ELEVATED CEREBROSPINAL-FLUID SUBSTANCE P-LIKE IMMUNOREACTIVITY IN PATIENTS WITH PAINFUL OSTEOARTHRITIS, BUT NOT IN PATIENTS WITH RHIZOPATICPAIN FROM A HERNIATED LUMBAR DISC

Cerebrospinal fluid (CSF) levels of substance P like immunoreactivity (SPLI) were determined in 11 patients with painful osteoarthritis in h ip or knee, 9 patients viith rhizopatic pain from a herniated lumbar d isc, and in 9 healthy volunteers without pain. The patients with osteo arthritis had increased levels of SPLI in CSF (p<0.001) compared to th e controls. A positive correlation was also seen between the CSF SPLI and the degree of pain. At a second lumbar puncture 5 months after ope ration, SPLI had decreased, but was still significantly higher than in the controls. No difference in CSF SPLI was seen in the patients with herniated lumbar disc compared to the controls, neither before treatm ent, nor at follow up CSF postoperatively. The results suggest that no ciceptive-joint pain is consistent with increased SPLI in CSF. Differe nces in SPLI in CSF may be useful to differentiate pain from various o rigin, and may also increase our understanding of different pain mecha nisms.