Intracarotid L-arginine reverses motor evoked potential changes in experimental cerebral vasospasm.

OBJECTIVE To investigate motor evoked potentials during short term L-arginine infusion in cerebral vasospasm after experimental subarachnoid hemorrhage. METHODS Three groups were designated for this study: control group, subarachnoid hemorrhage-saline infusion group, and subarachnoid hemorrhage-L-arginine infusion group. A subarachnoid hemorrhage was created by intracisternal injection of autologous blood in New Zealand rabbits. At the fourth day of subarachnoid hemorrhage, latency and amplitude of motor evoked potentials were recorded during intracarotid saline and L-arginine infusion, and compared with motor evoked potential parameters of the control group. RESULTS Motor evoked potential latencies were increased, and amplitudes were decreased in all animals before saline and L-arginine infusion on the fourth day of subarachnoid hemorrhage. A decrease in latencies as well as an increase in motor evoked potential amplitudes was observed with short-term intracarotid L-arginine infusion. CONCLUSION Intracarotid short term L-arginine infusion significantly improves motor evoked potential parameters after experimental subarachnoid hemorrhage.