Introduction: The decision to surgically decompress patients with symptomatic Chiari I malformations (CIM) is typically made on the basis of presence of a syrinx, degree of tonsillar ectopia, and progressive neurologic symptoms and with the goal of improving these symptoms. A small subset of patients with CIM do not, however, have symptom resolutions after posterior fossa decompression. This study analyzes a cohort of Chiari I patients whose symptomatology did not improve after decompression.
Methods: A retrospective chart review of all 195 patients who underwent decompression for CIM at a tertiary care institution from 2000-2016 was conducted. Patients were evaluated for resolution of their symptomatology postoperatively. Those patients with persistent symptoms were further reviewed through operative reports, pre and postoperative imaging, and patient progress notes.
Results: A total of 16 of the 195 (8.2%) patients had persistent symptoms following surgical decompression at an average recurrence interval of 22 days postoperatively. The most frequent persisting symptom postoperatively was headache in 12 patients (75%) at an average recurrence interval of 30 days postoperatively. Of those patients with persistent symptoms, 6 patients demonstrated the presence of syringomyelia or syrinx preoperatively. Additional persistent symptoms included back and neck pain (n=5), hypesthesia (n=3), and gait instability (n=2). Pseudomeningocele was noted in 8 patients, 7 of whom complained of headache. For those patients without pseudomeningocele, hormonal imbalances (n=2), presence of arachnoidal scarring (n=2), concurrent hypotension (n=2), fasciae complications (n=2) and other spinal cord pathologies (n=4) may have accounted for their persistent systems.
Conclusions: Headaches represented the most common persistent symptom following surgery for Chiari I. Persisting symptoms after surgery impose a significant effect on quality of life. This study demonstrates the importance of analyzing surgical outcomes in a patient-centered framework that focuses on factors that lead CIM patients to deteriorate to pre-operative symptom status.
Patient Care: By analyzing the factors which precipitate suboptimal outcomes for patients with Chiari I malformations, we will be better able to prevent them from occurring in the future.
Learning Objectives: To identify what explains suboptimal outcomes following decompression surgery for Chiari I malformations