Experimental neurogenic disorders of the bladder after section of cauda equina

Changes in the cystometric pattern and urethral pressure profile after surgical section of the cauda equina have been studied in a group of 20 monkeys (Macaca nemestrinal). The experimental autonomous bladder was characterised by tonic response to filling and with variable urethral dribbling incontinence but without co-ordinated detrusor activity. This pattern developed despite previous urinary diversion to prevent inadvertent overstretch of the bladder. Deliberate "overstretch" of the autonomous bladder was not followed by loss of tonus but was associated with the development of high amplitude regular detrusor contractions which were superimposed upon a steep rising filling cystometrogram. With urinary diversion the resting urethral pressure profiles were preserved after division of the cauda equina but were lower in amplitude after overstretch of the autonomous bladder.