ABSTRACT
Causalgiform pain was produced in adult rats(Sprague-Dawley) by the tight ligation of L5 and L6 spinal nerves. To verify the causalgiform pain, we tested spontaneous pain behavior', withdrawal sensitivity to the innocuous mechanical stimulation of Von Frey hair 2.35gm(mechanical allodynia); and withdrawal frequency to the cold stimulation of acetone (cold allodynia). The natural duration of causalgiform pain (control group, N=11) and the change of pain by surgical sympathectomy (sympathectomy group, N=9) was observed. The results were as follows 1) Mechanical allodynia(57.8%) and cold allodynia(63.2%) was induced on the postoperative 7th day. 2) Causalgiform pain was continued for 3 to 5 weeks in the control group. 3) Mechanical allodynia and cold allodynia was reduced significantly (P<0.05) after surgical sympathectomy in the sympathectomy group.