White Matter Injury in Spinal Cord Ischemia

Abstract
Background and Purpose —Spinal cord ischemia is a serious complication of surgery of the aorta. NMDA receptor activation secondary to ischemia-induced release of glutamate is a major mechanism of neuronal death in gray matter. White matter injury after ischemia results in long-tract dysfunction and disability. The AMPA/kainate receptor mechanism has recently been implicated in white matter injury. Methods —We studied the effects of AMPA/kainate receptor blockade on ischemic white matter injury in a rat model of spinal cord ischemia. Results —Intrathecal administration of an AMPA/kainate antagonist, 6-nitro-7-sulfamoyl-(f)-quinoxaline-2,3-dione (NBQX), 1 hour before ischemia reduced locomotor deficit, based on the Basso-Beattie-Bresnahan scale (0=total paralysis; 21=normal) (sham: 21±0, n=3; saline: 3.7±4.5, n=7; NBQX: 12.7±7.0, n=7, P Conclusions —Results indicate severe white matter injury in the spinal cord after transient ischemia. NBQX, an AMPA/kainate receptor antagonist, reduced ischemia-induced white matter injury and improved locomotor function.