Urodynamic findings in the tethered spinal cord syndrome: does surgical release improve bladder function?

We retrospectively reviewed 39 patients with a tethered spinal cord to evaluate whether surgical release positively influenced urological symptoms or urodynamic findings.

The patients were divided into 2 groups: group 1-11 with occult spinal dysraphism and group 2-28 with secondary spinal cord tethering after previous closure of a myelomeningocele or resection of a lipomyelomeningocele. Diagnosis was confirmed in all cases by magnetic resonance imaging or spinal ultrasound. A comprehensive urodynamic evaluation was done immediately preoperatively and 2 to 21 months (mean 7) postoperatively.

In group 1 the most common preoperative urodynamic finding was hyperreflexia, which improved or resolved after untethering in 62.5% of the patients. Four adults also reported improved bladder sensation or decreased urgency. In group 2 the most common urodynamic finding was impaired compliance, followed closely by detrusor hyperreflexia. Urodynamic patterns of detrusor hyperreflexia or compliance improved in only 30% of the patients, while 48% had worsened patterns. Only 14% of group 2 had improved symptoms of urinary control but 28% had improved lower extremity function.

Urological symptoms and urodynamic patterns may be improved by early surgical intervention in patients with occult spinal dysraphism. However, untethering did not consistently benefit patients with secondary spinal cord tethering.