SURGICAL TREATMENTS FOR SCOLIOSIS ASSOCIATED WITH SYRINGOMYELIA: STUDY ON NEUROLOGIC COMPLICATIONS

Makoto Tokunaga, MD;
Shohei Minami, MD;
Shinsuke Nishikawa, MD;
Hiroshi Kitahara, MD;
Keijiro Isobe, MD;
Hideshige Moriya, MD,
Yoshinori Otsuka, MD;
Yoshinori Nakata, MD;
Masashi Takaso, MD;
Masatoshi Inoue, MD

PURPOSE:
To clarify the aspects to be considered in regard to surgery for patients presenting scoliosis associated with syringomyelia.

PATIENTS AND METHODS:
The clinical records of 50 patients (21 males and 29 females), who had been diagnosed as having scoliosis associated with syringomyelia and had been operated on for syringomyelia, scoliosis or both, were investigated. We divided these patients into three groups according to the surgical procedures. Group 1 included 14 patients who were subjected to corrective surgery for scoliosis after surgery for syringomyelia such as foramen magnum decompression or shunt procedure. Group 2 included 21 patients subjected to corrective surgery for scoliosis alone. Group 3 included 15 patients subjected to surgery for syringomyelia alone. In each group, we mainly reviewed the postoperative changes of neurologic symptoms.

RESULTS:
The average age at the first surgery was 13.3 ± 3.8 years in Group 1, 15.5 + 2.7 years in Group 2 and 11.1 ± 4.9 years in Group 3, while the age at the final follow–up was 19.4 ± 5.9 years in Group 1, 24.4 ± 6.8 years in Group 2 and 16.9 ± 3.6 years in Group 3. Cobb angle at the surgery was 72.5 ± 26.6 degrees in Group 1, 70.9 ± 16.0 degrees in Group 2, and 28.4 ± 8.8 degrees in Group 3. All patients showed slight neurological abnormalities at their first visit. Neurologic complications early after surgery, which might have been caused by traction manipulation during surgery, were observed in three patients of Group 2: sciatica was in two patients, tight hamstrings was in one and hyperreflexia on legs was in one. All of these symptoms reduced spontaneously. Neurologic complications late after surgery (4 to 15 years after surgery), which might have been due to progression of syringomyelia itself, were observed in four patients of Group 2, and additional surgery for syringomyelia had little effect on these complications.

CONCLUSIONS:
This study reported a high frequency (14.0%) of postoperative neurologic complications. It increased to 33.3% in the patients who had not been treated for syringomvelia. Dealing with syringomyelia previous to spinal corrective surgery is necessary to avoid not only early neurologic complications but also delayed complications, especially if the syrinx is large or tonsillar herniation is severe.