Reflex conditioning in a spinal man.

A man with a completely transected spinal cord and a spastic neurogenic bladder was conditioned to void upon the presentation of an external stimulus. A classical conditioning paradigm was employed in which strong abdominal shock (unconditioned stimulus) was paired with an initially neutral mild electrical stimulation of the thigh (conditioned stimulus; CS). After the pairing trials, a reliable conditioned response of urination was elicited by the CS alone. The conditioned response did not extinguish over time, and the procedure left the bladder with clinically safe residual amounts of urine. Practical implications of the conditioning technique for the treatment of spastic neurogenic bladder conditions in spinally injured patients are discussed, as is the theoretical significance of conditioning at the reflex level in the absence of cortical involvement.