Early predictors of bladder recovery and urodynamics after spinal cord injury

Our purpose was to determine if intact perianal (S4-5) pin sensation (PPS) and bulbocavernosus (S2-4) reflex (BCR) shortly after spinal cord injury (SCI) are predictive of bladder function recovery. Twenty-eight SCI patients (aged 18-68 years, Frankel Classification A-D, spinal injury level C4-T12), admitted within 72 hours of injury, underwent evaluation of initial PPS and BCR. The presence of intact PPS and BCR were correlated with the patient's voiding function and urodynamic evaluation results 1 year postinjury. Of the 28 patients within 72 hours of SCI, PPS was intact in 17 (60%) and absent in 11 (40%), while 15 patients (54%) demonstrated a positive BCR and 13 (46%) did not. One year after SCI, no patient with absent PPS voided unassisted, while of the 17 patients with preserved PPS, 11 (65%) were voiding spontaneously. Of these 11 patients, urodynamic evaluation revealed detrusor areflexia in 1 (9%), normal detrusor function in 2 (18%), and detrusor hyperreflexia in 8 (73%), with 3 of these 8 patients (38%) also demonstrating detrusor-sphincter dyssynergia. At 1 year postinjury, only 2 of 13 patients (15%) with an absent BCR voided spontaneously, while 9 of 15 patients (60%) with an intact BCR were able to void. Although PPS and BCR are moderately sensitive in predicting the return of spontaneous voiding, they cannot predict detrusor hyperreflexia and sphincter dyssynergia. Therefore, urodynamic study remains an essential component of initial urologic evaluation after SCI.