Intrathecal corticoids in permanent focal cerebral ischemia in rats. Part I: a new therapeutic approach in the acute phase.

Intrathecally, triamcinolone acetonide (TCA) was suggested to have neuroprotective efficacy on infarction volume in acute focal cerebral ischemia in rats. In the first dose-finding study, TCA in five different doses or saline was administered into the cisterna magna of 12 rats, each 30 mins after endovascular occlusion of the middle cerebral artery (MCAO). In the second magnet resonance controlled confirmation study, the most neuroprotective dose was compared with controls in each of the 15 rats. Infarction volume was calculated at 24 h by 2.3.5 triphenyl-tetrazolium-chloride staining. Compared with controls (18.2%), infarction volume was significantly reduced using TCA at a dose of 0.012 mg/kg body weight (BW) (13.4%, P=0.04). TCA at doses of 0.03 (17.7%, P=0.84), 0.006 (15.9%, P=0.24), and 0.003 mg/kg BW (14.5%, P=0.11) did not significantly reduce infarction size. TCA 0.3 mg/kg BW resulted in bilateral infarction with increased infarction volume (19.8%, P=0.49). Magnetic resonance imaging confirmed successful MCAO and intrathecal administration. In experiment 2 compared with controls (20.0%), infarction volume was significantly reduced using TCA 0.012 mg/kg (13.4%, P=0.02). Intrathecally, TCA may significantly reduce infarction volume in acute focal cerebral ischemia in rats. Further studies are necessary to define the value of this therapy.