The most frequent cause of syringomyelia is obstruction of the subarachnoidal space in the area of the craniocervical transition or at a spinal level. Between different pathological processes predominate changes the complex of which forms the Chiari malformation (ChM) grade I. Of 23 adults operated on account of ChM 15 suffered also from syringomyelia, for which two had been previously operated. The group included 13 previously non-operated patients (8 women, 5 men) aged 40–60 years (mean 49.8 years). Surgical treatment involved in all instances partial suboccipital craniectomy, laminectomy C1, three times also C2, opening of the dura mater, adhesiolysis of the cerebellar tonsils and plastic operation of the dura mater by an autograft from the fascia lata. To restore the patency of the for. Magendi in 9 instances also partial subpial resection of gliotically altered tonsils was necessary. 7–63 months after surgery (mean 34) improvement of the clinical condition with varying progression of the disease was observed. Diminution, rarely disappearance of the syringomyelic cavity was observed in 85% cases. The only complication was an epidural cerebrospinal liquor pseudocyst which called for re-operation. The operation involved bone decompression of the craniocervical transition restoration of the patency of the for. Magendi and plastic surgery of the dura mater which appears to be one of the most effective methods of surgical treatment of syringomyelia in ChM of adults.

        Key words: syringomyelia, Chiari malformation, surgical treatment