Management of Chiari I Malformations with Holocord Syringohydromyelia

The management of patients with Type I Chiari malformations (CM 1) with or without syringohydromyelia (SHM) has remained quite controversial, and many different surgical procedures have been advocated. Over the past several years, the authors have treated 7 children presenting with CM 1 and holocord syringohydromyelia with suboccipital decompression and duraplasty alone without intradural procedures. All children received MRI imaging at 2-4 months and 1 year postoperatively. On the early postoperative MRI examination, marked reduction in the syringohydromyelia was seen in 6 children, with minimal change in syrinx size in 1 child who was clinically improving after the operation. At 1 year, all children with early collapse remained collapsed, and the child with minimal early collapse demonstrated an approximately 50% reduction in syrinx size. Clinical follow-up (mean 30 months, range 21-50 months) showed good results in all patients: none of the children have required further neurosurgical intervention, and all have shown improvement in their preoperative function. One child with a 46 degrees scoliosis had a complete collapse of her SHM, but ultimately required spinal fusion. The presenting clinical findings, operative technique, MRI imaging and clinical outcomes will be discussed. The results from these 7 patients with CM 1 and holocord syringomyelia suggest that posterior fossa decompression alone (without intradural procedures) can provide excellent radiographic and clinical outcome.