Abstract
Neuropathic pain affects about 7 to 10 % of the population. Although neuropathic pain has been extensively studied, effective treatment has not yet been established.
Several animal models have been developed for neuropathic pain research. The most commonly used animal model to induce peripheral neuropathic pain is chronic sciatic nerve constriction, which is considered as the CRPS II model.
However, the methodology of pain modeling and measurement is not uniform and includes several variations that may affect the outcome. Therefore, we performed an analysis of the methodologies used in articles published in Q1 journals of the field of anesthesiology over a 10-year period.
We researched from these articles: the laboratory rat strains, the anesthesia, the pain threshold values, the type of tests, the time interval of measurement after surgery, the preoperative measurements, and the type of control. We found that in all studies the laboratory rat strain used was Sprague Dawley and the most commonly chosen anaesthetic was pentobarbital and to a lesser extent isoflurane.
Furthermore we found that the plantar test is the most common used test. The value of the pain threshold is most often about 10-13,5 seconds and decreases to 33-61% of the original values one week after the operation.
SHAM operated animals are the most commonly used controls. Finally, we created an overview/recommendation of the modelling and measurement of pain in the chronic constriction injury of the sciatic nerve based on this analysis.