Syringomyelia associated with Chiari I malformation treated by cranio-vertebral decompression with resection of the cerebellar tonsils. Report of 8 cases

We report a series of 8 patients with syringomyelia and associated Chiari I malformation treated between 1992 and 1996 using a cranio-vertebral decompression with tonsil resection. The follow up period ranged from 6 months through 4 years (mean: 28 months). Neurological symptoms and signs improved in 7 patients (87 %), and were stabilized in 1 (13 %). At 6 months, postoperative MRI showed that the syringe has decreased in all patients. We emphasize the respect of the different stages of surgical procedure (limited foramen magnum opening, arachnoid preservation, tonsillar subpial aspiration, arachnoid suture and dural closure). Other of treatment and their results are reviewed.