Botulinum A toxin as a treatment of detrusor- sphincter dyssynergia in patients with spinal cord injury: MRI controlled transperineal injections

OBJECTIVES—To correlate clinical and urodynamicfindings with MRI in patients with spinal cord injury anddetrusor-sphincter dyssynergia who were consecutively treated withtransperineal injections of botulinum-A toxin (BTX-A) under EMG control.
METHODS—Six patients with spinal cord injury andupper motor neuron bladder dysfunction associated with detrusor-sphincter dyssynergia were prospectively analysed. One hundredinternational units (IU) BTX-A (Botox® in 1 ml normal saline withoutpreservative) diluted 1 to 1 with 1 ml gadopentetate were injectedtransperineally under EMG control. MRI was started immediately afterneedle withdrawal.
RESULTS—In all six patients gadopentetate waslocated in the external urethral sphincter on MRI. In no patient didtraces of gadopentetate appear in the perineal musculature located inthe vicinity of the external urethral sphincter. No patient developedresistance to BTX-A. All patients showed an (ongoing) improvement oftheir voiding function after BTX-A injections.
CONCLUSIONS—Transperineal injections of BTX-Aunder EMG control are efficient in the release or amelioration of lowerurinary tract obstruction due to detrusor sphincter dyssynergia inpatients with spinal cord injury. Despite well described methods, EMGof the external urethral sphincter is difficult and it is not possibleto definitively exclude false recordings of the surrounding perinealmusculature. By the use of MRI it was shown that both the EMGrecordings and transperineal injection method are precise.