PFDD Versus PFDRT in Chiari Decompression Surgery

Type of Surgical Intervention for Chiari Malformation-syringomyelia: a Multicenter Randomized Controlled Study

The purpose of this study is to determine whether a posterior fossa decompression and duraplasty with or without tonsil manipulation results in better patient outcomes with fewer complications and improved quality of life in those who have Chiari malformation type I and syringomyelia.

Participants with Chiari Malformation type I and syringomyelia will be randomized to either have a posterior fossa decompression and duraplasty with or without tonsil manipulation. The participant will then return to the neurosurgeon's office at the following time points which are consistent with standard of care practice: 3-6 months, 12 and 24 months. At these visits, the clinician will complete a physical exam and the participant will report on the prognosis of symptoms and complete questionnaires. A spine MRI will be performed 3-6 months, 12 and 24 months after the surgery.

Inclusion Criteria:

• Age ≥14 years old
• Chiari malformation type I ≥5 mm tonsillar ectopia
• a syrinx with a width > 50% of the cross-sectional diameter of the spinal cord , and a length of at least 2 cervical and/or thoracic vertebral segments.
• MRI of the brain and cervical and thoracic spine are required prior to surgery and must be available to be shared with the Data Coordinating Center

Exclusion Criteria:

• included one or more of the following preexisting conditions: hydrocephalus; tumor; brain trauma; stroke; meningitis; abscess;
• other congenital anomalies of the brain or skull base; vertebral anomalies (i.e., Klippel-Feil, atlas assimilation, etc.);
• degenerative or demyelinating disease;
• CM-I without syringomyelia;
• syringomyelia with cerebellar tonsils in a normal position;
• fibromyalgia;
• chronic fatigue syndrome;
• prior posterior fossa surgery.
• Unable to share pre-decompression MRI of the brain and spine Patients who do not wish to participate