Value of sensory examination in predicting bladder function in patients with T12-L1 fractures and spinal cord injury

To determine whether early sensory examination, voluntary anal sphincter contraction, or bulbocavernosus reflex (BCR) might predict bladder function in patients with a spinal fracture at the thoracolumbar level.

Longitudinal study of consecutive patients admitted to a spinal cord injury (SCI) rehabilitation center.

Primary care center, university facility in Switzerland.

Fifty-five patients with thoracolumbar fractures.

Neurologic (American Spinal Injury Association [ASIA] protocol) and urodynamic examination during the first hospitalization and at follow-up.

Neurologic sensory scores and type of neurogenic bladder.

At first examination, there was no correlation between the sensory examination, voluntary anal sphincter contraction, BCR, and neurogenic bladder type. At follow-up (time since first examination: mean, 698+/-47.2d; median, 481d), the sensory examination remained of no value in distinguishing the neurogenic bladder type. However, voluntary anal sphincter contraction distinguished between complete and incomplete neurogenic bladders and BCR differentiated between complete bladder dysfunction of the lower motoneuron and upper motoneuron type. At follow-up, the bladder function (51 patients) remained unchanged in 44 cases and normalized in only 7 cases. Patients who improved their bladder function tended to have higher initial sensory ASIA scores (P<.05, Kruskal-Wallis test). Of the 7 patients who improved their bladder function, all but 1 (85%) had initial perineal pinprick sensation. Nevertheless, preservation of perineal pinprick sensation was of no positive predictive value, because 21 patients (48%) who initially had perineal pinprick sensation did not improve their voiding function, a finding similar to that of the 23 (52%) without initial perineal pinprick sensation whose bladder function also did not improve.

In SCI patients with thoracolumbar fractures, neurogenic voiding dysfunction cannot be predicted by the sensory evaluation. In patients with an SCI at the thoracolumbar level, pinprick sensation in the perineal area is of negative predictive value: absence of pinprick sensation predicts poor bladder recovery. Most patients with a spinal fracture at T12-L1 did not improve in voiding function.