measure the dorsal columns (pathways lying on the back of the
spinal cord) of the spinal cord. This is helpful during
surgery, as an assurance that the spinal cord is intact.
When operating around and in the spinal cord, a patient cannot
tell us whether he/she is experiencing injury to the spinal
cord which might affect the upper or lower extremities, but
ssep's may give us a warning. A shock is given in the
distribution of a peripheral nerve, and the conduction is measured
as it travels to the brain. To measure ssep's, electrodes
are attached to the extremities and scalp.