The autonomous neurogenic bladder results from destructive lesions of the cauda equina or conus terminalis. The bladder is totally deprived of its essential innervation by the parasympathetic division of the autonomic nervous system. The detrusor becomes hypertonic, but, because of the destruction of the spinal reflex, all reflex contractions are abolished. Bladder sensation is lost and voluntary sphincteric control is destroyed (fig. 1).
Sharing in the hypertonicity of the detrusor are those circularly arranged fibers at the vesical neck described as the internal sphincter. The hypertonic internal sphincter acts as a definite obstruction, almost exactly analagous to having contracture of a vesical neck superimposed on the entire picture. As a result, urine does not escape from the bladder until the intravesical pressure exceeds the obstruction in the outlet. Since reflex activity of the bladder is lost, voiding is accomplished only by straining or by continuous overflow dribbling incontinence. As time