High incidence of occult neurogenic bladder dysfunction in neurologically intact patients with thoracolumbar spinal injuries.

PURPOSE: We determine the relationship between lower urinary tract function and somatic neurological status after thoracolumbar fracture.
MATERIALS AND METHODS: Within 72 hours of thoracolumbar vertebral fracture we evaluated 44 consecutive patients, including 30 men and 14 women 17 to 84 years old (mean age 38.7), with occult neurogenic bladder dysfunction following incomplete thoracolumbar spinal injuries (American Spinal Injury Association impairment classifications C to E). The neurological level and degree of injury were established, and testing for perianal pinprick sensation and bulbocavernosus reflex was done. Video urodynamic evaluation was then performed between 3 and 14 days after injury but before spinal surgery.
RESULTS: Urodynamics revealed neurogenic lower urinary tract dysfunction in all 10 patients with classification C, 82% with D and 41% with E (otherwise completely intact neurologically) impairment. Although pinprick sensation deficiency and decreased bulbocavernosus reflex correlated with injury classification, lower urinary tract dysfunction was present in 62% of the patients with intact pinprick sensation and in 59% with intact bulbocavernosus reflex.
CONCLUSIONS: Neurologically intact patients with thoracolumbar spinal injuries may have neurogenic lower urinary tract dysfunction on urodynamics. Pinprick sensation and bulbocavernosus reflex are specific but not sensitive indicators of lower urinary tract dysfunction after spinal cord injury. Although these indicators, which demonstrate somatic nerve function, were absent in all patients with detrusor areflexia, intact pinprick sensation and bulbocavernosus reflex are not sensitive for predicting lower urinary tract function, which depends on autonomic nerve function. Urodynamic evaluation is mandatory for the complete evaluation of patients with incomplete lumbosacral spinal injuries.