METHYLPREDNISOLONE TREATMENT OF EXPERIMENTAL SPINAL-CORD INJURY

Lipid peroxidation has been identified as a deleterious consequence of contusive spinal cord trauma and of thermal injury. The L3-L6 spinal cord segment was thermally injured using a radiofrequency heating cham ber mounted on the vertebral column of anesthetized rats. Hind limb fu nction was assessed 2 hours later. A bolus of methylprednisolone (MP, 30 mg/kg) was then given intravenously, followed by 5.4 mg/kg/hr MP fo r 6 or 24 hours. Cord water content and regional spinal cord blood flo w (RSCBF, C-14-butanol distribution) were measured at seven cord level s after function had been reassessed following treatment. Untreated ra ts were given vehicle. The study was randomized and blinded. Results: Edema in heated segments was progressive over 24 hours, but was the sa me in treated vs untreated rats. RSCBF in heated segments was the same in treated vs uninjured controls at 6 and 24 hours. In untreated rats , RSCBF in the heated segment was elevated by 30% at 6 hours, but was the same as uninjured control by 24 hours. In the unheated segments of untreated rats, RSCBF was elevated at 24 hours. At 24 hours, RSCBF wa s lower in treated vs untreated rats at all levels, including the heat ed one. Limb function deteriorated equivalently in both groups. Conclu sion: MP obviated the early rise in RSCBF in heated segments and the e levations in RSCBF in uninjured segments, but had no effect on cord ed ema or on limb function.