Central post-stroke pain (CPSP) is one of the most troublesome sequelae of stroke. It is characterized by persistent pain, resulting in marked deterioration in daily living activities and quality of life (QOL). In recent years, the rat model of CPSP using collagenase-IV induced cerebral hemorrhage has been increasingly reported.
In this study, we attempted to establish an assessment system of analgesics in CPSP model. Male SD rats were induced cerebral hemorrhage by means of microinjection of collagenase-IV into the lateral thalamic area. The pain thresholds was evaluated with von Frey filament test and planter test. Analgesics were orally administered one hour before measurement.
Hemorrhagic lesions were observed in the lateral thalamic region of the CPSP model rats. Pain thresholds of the CPSP model rats were decreased compared with the sham operated rats. In addition, the efficacy of analgesics on CPSP was confirmed.
These results indicate the CPSP model was established using the current method. The model would be useful to evaluate potential efficacy of newly developed analgesics.