Improvement in Neurogenic Bowel and Bladder Dysfunction Following Posterior Decompression Surgery for Cauda Equina Syndrome: A Prospective Cohort Study

OBJECTIVE: The mechanisms of neurogenic bowel dysfunction (NBD) and neurogenic bladder (NB), which are major consequences of spinal cord injury and occasionally degenerative lumbar disease. The following in patients with cauda equina syndrome who underwent posterior decompression surgery was investigated: (1) the preoperative prevalence of NBD and NB, measured using the Constipation Scoring System (CSS) and International Prostate Symptoms Score (IPSS); (2) the degree and timing of postoperative improvement of NBD and NB. METHODS: We administered the CSS and IPSS in 93 patients before surgery and at 1, 3, 6, and 12 months postoperatively. We prospectively examined patient characteristics, Japanese Orthopaedic Association (JOA) score, and postoperative improvements in each score. RESULTS: The prevalence of symptomatic defecation and urinary symptoms at admission were 37 patients (38.1%) and 31 patients (33.3%), respectively. Among the symptomatic patients with defecation problems, 12 patients had improved at 1 month, 13 at 3 months, 14 at 6 months, and 13 at 12 months postoperatively. Among the symptomatic patients with urinary problems, 5 patients improved at 1 month, 11 at 3 months, 6 at 6 months, and 10 at 1 year postoperatively. Comparing patients with improved versus unimproved in CSS, the degree of JOA score improvement was a significant prognosis factor (p<0.05; odds ratio, 1.05). CONCLUSION: The prevalence of symptomatic defecation and urinary symptoms in patients with cauda equina syndrome was 38.1% and 33.3%, respectively. Decompression surgery improved symptoms in 30%–50%. These effects were first observed 1 month after the operation and persisted up to 1 year.