saddle anesthesia saddle anesthesia saddle anesthesia is a loss of sensation (anesthesia) restricted to the area of the buttocks, perineum and inner surfaces of the thighs. saddle anesthesiaapproximate area of "saddle anesthesia" seen from behind (yellow highlight)differential diagnosiscauda equina syndrome asymmetric saddle anesthesia is frequently associated with the spine-related injury cauda equina syndrome. it is also seen symmetrically with conus medullaris and may occur as a temporary side effect of a sacral extradural injection.