Usefulness of Current Withdrawal Threshold on Evaluation of the Neuropathic Pain in Animal Model

ABSTRACT

OBJECTIVE: To evaluate usefulness of the current withdrawal threshold (CWT) on evaluation of the neuropathic pain in animal model. METHOD: Surgical neuropathy was induced in 40 Sprague-Dawley rats. Fourteen days after the surgery, neuropathic rats were evaluated by von Frey hair. The CWT was determined by various stimulus intensities which induce the tail-withdrawal response or vocalization of rats. The experimental group was compared with the control group by CWT. Then the experimental group was subdevided to two groups. The experimental group 1 was injected with beta-methasone 0.1 mg/kg, intra-peritoneally and experimental group 2 was injected with normal saline with the same amount as steroid. The CWT of two experimental subgroups were measured before and 30 minutes after injections. RESULTS: The experimental group showed significant decrease of the CWT compared with the control group after the neuropathic pain was induced. The CWT of experimental group 1 was increased after steroid administration (p<0.01). CONCLUSION: This preliminary study suggests that the measurement of CWT would be an useful tool to study the neuropathic pain in experimental animal model.