Functional Outcome for Chiari Malformation Using a Novel Scoring System

Abstract

Background The authors report functional outcomes comparing various surgical techniques, using a Chiari-specific assessment tool. They also intend to externally validate the performance of the CCOS by comparing with gestalt outcome. Methods Total cohort comprised 73 surgically treated patients, and patients were divided into two groups: patients who were operated upon at the authors’ institute and those who were evaluated at their institute but underwent surgery elsewhere due to various reasons. Functional outcome was evaluated on the basis of the Chicago Chiari outcome scale (CCOS) and gestalt outcome scale. Mean duration of follow-up was 10.23 ± 5.8 months. Results In the authors’ cohort of 73 patients, 76.70% (n = 56) were improved, 23.30% (n = 17) were unchanged, and none of them deteriorated. The median CCOS was 14 ± 1.34 (range: 11–16). There was no statistical difference in outcome between the different operative groups (foramen magnum decompression, duraplasty, tonsillar resection “other”). The CCOS value of 14 has excellent sensitivity (0.95) and good specificity (0.746) for identifying patients with good gestalt outcome. Conclusion The authors found a clear correlation between higher CCOS score and gestalt outcome. There was no statistical difference in outcome between the different operative groups.

Keywords

• chiari malformation
• syrinx
• functional outcome
• chicago chiari outcome scale
• posterior fossa decompression