Acute Pressure Block of the Sciatic Nerve Relieves Clinical Pain But Not Cold Pressor Pain

OBJECTIVESAcute pressure applied to the sciatic nerve has been recently reported to offer immediate short-term pain relief in patients with various diseases. This study examined the analgesic effect of this novel method on cold pressor pain compared with clinical pain. METHODSWe conducted 2 randomized, parallel, group studies. The cold pressor study involved 152 undergraduate students and the clinical study included 22 cancer patients. Acute pressure of 11 to 20 kg was simultaneously applied to the sciatic nerves at the back of both thighs for 2 minutes. The placebo intervention was pressure applied to parallel regions on the fronts of the thighs. Next, patients rated pain attributable to their diseases and the students evaluated pain after their hands were submerged in cold water. RESULTSAcute pressure applied to the sciatic nerve produced immediate clinical pain relief, but did not alleviate cold pressor pain. DISCUSSIONOur study indicated that cold pressor pain and clinical pain responded differently to acute pressure blockade of the sciatic nerve. Our findings indicate that caution should be exercised when attempting to extrapolate cold pressor pain findings to clinical pain.