The effects of large doses of methylprednisolone on neurologic recovery and survival in the Mongolian Gerbil following three hours of unilateral carotid occlusion

Using a scoring system designed to assess the severity of neurologic deficit in gerbils during and after temporary unilateral carotid occlusion, the effects of large doses of methylprednisolone sodium succinate (MPSS: Solu-Medrol sterile powder) on experimental stroke have been examined. By scoring gerbils hourly for torso curvature, circling, inability to walk, ptosis, barrel rolling, opisthotonus, generalized seizures, and loss of righting reflex, their level of neurologic deficit can be easily, quantitatively, and reproducibly evaluated. Approximately 37% of gerbils subjects to a 3-hour unilateral carotid occlusion attained average scores of 4.0-4.5 during the first hour. There was a slight, though not significant, worsening (increase) of scores over the 3-hour occlusion period that was not altered by pretreatment of gerbils with 60 mg/kg of MPSS 10 minutes before occlusion. Following removal of occlusion at 3 hours, gerbils recovered only minimally during the ensuing 4-hour period, with deficit scores remaining around 3.2 +/- 0.3. Pretreatment of gerbils with 60 mg/kg of MPSS, however, resulted in a striking improvement in their deficit scores to 1.6 +/- 0.2 (p less than 0.05) by 2 hours after occlusion removal. Treatment of gerbils with lower (30 mg/kg) or higher (100 mg/kg) doses of MPSS was not as effective in promoting improvement. The survival of 3-hour occluded gerbils was significantly enhanced by pretreatment with 60 mg/kg of MPSS. Vehicle-treated gerbils had survival rates of 41.7%, 16.7%, and 16.7% at 24 hours, 48 hours, and 7 days, respectively, compared with 90.9%, 72.7%, and 45.4%, respectively, for MPSS-treated gerbils.