Urodynamic findings in adults with the tethered cord syndrome

We evaluated bladder function in adults with the tethered cord syndrome using multichannel urodynamics.

A total of 21 patients a mean 39.6 years old (range 20 to 62) with a tethered cord were evaluated. Of the patients 13 were diagnosed with a tethered cord as an adult and 8 had undergone previous spinal surgery. The tethered cord syndrome was diagnosed by magnetic resonance imaging in 20 patients and computerized tomography myelogram in 1. All patients underwent complete neurological and urological evaluation, including multichannel urodynamics. Needle electromyography and video urodynamics were performed in select cases. Microsurgical release of the tethered cord was performed in 19 patients and 2 refused surgery. Urodynamics were done before surgery in 16 of 19 patients and a median of 12.5 months (range 1 to 40) after surgery in 14. In addition, intraoperative urodynamic monitoring and nerve root stimulation were done in 14 patients to prevent nerve root injury at surgery.

At presentation urgency (67%) and urge incontinence (50%) were the most common findings in 18 patients with urinary symptoms. Pretreatment urodynamics in 18 of 21 patients revealed hyperreflexia in 13 (72%), external detrusor-sphincter dyssynergia in 4 (22%), decreased sensation in 4 (22%), decreased compliance in 3 (17%) and hypocontractile detrusor in 2 (11%). Postoperative urodynamic findings were improved in 4 patients (29%) and unchanged in 10 (71%). Preoperative external detrusor-sphincter dyssynergia in 4 patients resolved postoperatively in 3 and was unchanged in 1. Urinary symptoms were improved in 19% of patients (4), unchanged in 76% (16) and worse in 5% (1). To date 7 patients require anticholinergics, 4 require clean intermittent catheterization and 1 is taking an alpha-blocker.

Adults with the tethered cord syndrome are less likely to have urodynamic or symptom improvement after cord release and most often present with irreversible findings which rarely become worse after surgery. These patients need to have careful and continuous followup, including urodynamic studies, due to possible re-tethering with time.