Experimental study on changes of the spinal-evoked potential and circulatory dynamics following spinal cord compression and decompression.

In an attempt to elucidate the pathogenesis of spinal cord injury, the authors investigated the changes in spinal-evoked potential (SEP) and serial fluorescein angiography during compression and after decompression of the thoracolumbar cord in dogs. The degree of compression was correlated well with the changes in SEP during compression and after decompression. The findings of serial fluorescein angiography immediately after decompression indicated hyperemia and extravasation of the fluorescein dye, especially in the group weighted with 36 and 60 g. Poor filling of the arteries and veins with fluorescein dye, and prolongation of the regional circulation time were observed at between 30 and 120 minutes after decompression in the group weighted with 36 and 60 g. These findings suggest that secondary circulatory disturbance plays an important role in the pathogenesis of spinal cord injury. The relation between changes of SEP and the circulation are also discussed.