Changes in spinal cord function evaluated by evoked potentials and spinal cord blood flow from a lateral retraction post-cervical laminectomy

We induced ischemia and stretching by retraction of the spinal cord after laminectomy in 12 anesthetized mongrel adult cats, recorded spinal motor evoked potential (SpMEP) and spinal somatosensory evoked potential (SpSSEP) and determined the spinal cord blood flow (SCBF). The results showed a correlation between progressive deterioration of the function and a decrease in SCBF. Comparing the abnormal findings of both the peak and interpeak latencies in evoked potentials, useful data were more frequently obtained using SpSSEP than SpMEP. Factors involved in their deteriorations seem to be a moderate ischemia by compression, and a stretching by the retraction of the spinal cord. From these results, we conclude that SCBF and SpSSEP are important for monitoring the impulse propagation during retraction of the cervical cord.