Clinical significance of terminal syringomyelia in association with pediatric tethered cord syndrome.

An association between terminal syringomyelia (TS) and tethered cord syndrome (TCS) has been recognized. The clinical significance of TS and the need for concurrent treatment is not known. Thirty-four patients with TCS undergoing surgery for tethered cord release were evaluated for the incidence of TS. The clinical and radiological response to untethering with and without syrinx drainage was assessed. The group incidence of TS was 29.4%. There were no significant differences in the sex, age, underlying pathology or preoperative symptoms between the TCS group (TCS, n = 24) and the TCS group with TS (TCS + TS, n = 10). In the TCS group, 37.5% of the patients were asymptomatic preoperatively, and in the TCS + TS group 50% were asymptomatic preoperatively. After surgery, none of these asymptomatic patients developed symptoms. All of the symptomatic TCS + TS patients improved clinically, 12 of 15 symptomatic TCS patients improved, 2 patients were unchanged and 1 had worsening scoliosis. Syrinx did not develop in patients lacking it preoperatively. In patients where postoperative imaging was available, preoperative syringes improved. TS is clearly associated with TCS. Tethered cord release alone may be sufficient to improve preoperative symptoms and TS may be an associated phenomenon that does not mandate separate treatment.