Pre-surgical assessments of CSF flow and brain motion are indicative of improved cerebral dynamics following surgery in Chiari Malformation I

Motivation: Chiari Malformation I (CM-I) is a condition characterized by cerebellar tonsil herniation, leading to reduced cerebrospinal fluid (CSF) flow and various neurological symptoms. Posterior fossa decompression (PFD) surgery can relieve symptoms, but surgical decision making is often unclear. Goal(s): Tonsillar descent poorly correlates with symptoms and surgical outcomes. We seek to better characterize the cerebral dynamic effects of CM-I and PFD surgery. Approach: Measure CSF flow using PCMR, and brain motion using DENSE, before and after PFD surgery. Results: Surgery showed best improvement in patients with significantly restricted pre-surgical CSF flow or severely increased pre-surgical brain motion, regardless of amount of tonsillar descent. Impact: Presurgical indicators of an individual’s likelihood of surgical improvement are critical in developing informed care plans. We find that direct measures of cerebral dynamics outperform standard measures of tonsillar decent at predicting improvement from posterior fossa decompression surgery in CM-I.