Objective: To investigate neurourologic involvement in injuries to the thor
acolumbar vertebra junction with magnetic resonance imaging (MRI) and elect
rophysiologic and urodynamic measurements and to characterize the neurogeni
c mechanisms of voiding dysfunctions.
Design: Baseline comparisons among 3 anatomic groups before neural repair.
Setting: Tertiary care center.
Patients: Thirty-five T11 to L2 spinal cord injury patients consecutively a
dmitted to a rehabilitation unit. Eight patients (Group 1) had above-conus
lesions without denervation and polyphasic waves revealed in the anal sphin
cter electromyography; 13 patients (Group 2) had conal and/or above-conus l
esions and anal sphincter electromyographic abnormalities; and 14 patients
(Group 3) had below-conus lesions and anal sphincter electromyographic abno
rmalities.
Main Outcome Measures: Comparison of features identified on pudendal nerve
terminal motor latency, urethral pressure profiles, and multichannel voidin
g pressure-flow study.
Results: The pudendal nerve terminal motor latency in Group 3, showing a si
gnificantly higher abnormal ratio (100%; p = .011, Fisher's exact test), in
dicated that cauda equina lesions might be the cause, Urodynamic data from
Group 3 showed a significant decrease in maximal urethral closure pressure
(48 +/- 17cmH(2)O, p = .0022, analysis of variance [ANOVA], repeated measur
e) and an increase in bladder capacity (429 +/- 194mL, p = .037, ANOVA, rep
eated measure). There were no significant changes in the other groups.
Conclusion: Neurourologic abnormalities are less predictable with injuries
to thoracolumbar junction, except in patients with cauda equina lesions.