| Characteristic | ⩽18 years (n = 20) | 19–30 years (n = 10) | ⩾31 years (n = 16) | p Value |
| Sex (M/F ratio) | 8/12 | 6/4 | 6/10 | NS |
| Chiari malformation I/II ratio | 15/5 | 10/0 | 15/1 | <0.005 |
| EDS (%) | 5 | 20 | 56 | <0.001 |
| Snoring (%) | 35 | 80 | 69 | NS |
| BMI | 19.1 (1.0) | 23.4 (1.8) | 26.9 (1.4) | <0.001 |
| Neurological symptoms (%) | ||||
| Pain | 45 | 100 | 94 | <0.001 |
| Motor weakness | 25 | 60 | 75 | <0.01 |
| Cerebellar signs | 20 | 20 | 31 | NS |
| Dizziness | 0 | 20 | 12 | NS |
| Nystagmus | 10 | 20 | 25 | NS |
| Vocal cord paralysis | 0 | 10 | 19 | NS |
| Trigeminal sensory loss | 0 | 10 | 25 | NS |
| IX and/or X palsies | 10 | 70 | 19 | <0.01 |
| Sensory loss | 55 | 70 | 56 | NS |
| Impaired deep sensibility | 0 | 20 | 19 | NS |
| Pyramidal tract signs | 20 | 40 | 44 | NS |
| MRI findings (%) | ||||
| Basilar impression | 10 | 60 | 10 | <0.001 |
| Syringomyelia | 65 | 60 | 56 | NS |
BMI, body mass index; EDS, excessive daytime sleepiness
Patients ranged from 4 to 64 years of age. Analysis of the effect of age group on continuous variable was tested by one way ANOVA with corresponding p significance values. Pearson χ2 tests were used for dichotomous variables.