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
