Prediction of the outcome of bladder dysfunction based on electrically induced reflex findings in patients with cauda equina syndrome

The evaluation of the electrically induced bulbocavernosus reflex (BCR) using electromyography (EMG) is a useful tool for evaluating the integrity of sacral spinal segments 2 to 4, and that of their afferent and efferent connections in the urogenital region. In the current retrospective study, the value of this technique in predicting the outcome of bladder dysfunction was investigated in patients with cauda equina syndrome (CES). Electrically induced BCR (E-BCR) was evaluated in 40 patients with bladder dysfunction due to CES at the subacute stage (7-90 days). Manually examined BCR, perianal pinprick sensation, and voluntary anal contraction were also investigated. The recovery of bladder function was evaluated 1 year after the onset of CES. All patients with the presence of E-BCR showed successful recovery of the bladder function, while all patients in whom E-BCR was absent showed poor recovery. E-BCR showed a higher positive predictive value than perianal pinprick sensation and voluntary anal contraction, and showed a higher negative predictive value than manually examined BCR. Results show that E-BCR has advantages in predicting the outcome of bladder dysfunction. Thus, this method can be used as a reference to predict the final outcome of bladder dysfunction at the subacute stage of CES.