gms | German Medical Science

Objective: Chiari I malformation is associated with an obstruction of cerebrospinal fluid (CSF) flow at the foramen magnum. CSF flow can be visualised using dynamic phase-contrast magnetic resonance imaging (MRI). We conducted this study to investigate the presence or absence of syringomyelia in patients with Chiari I malformation.

Methods: Dynamic phase-contrast MRI of the entire central nervous system was used to investigate 90 patients with Chiari I malformation. There were 61 females and 29 males with a mean age of 39 years (median age: 40 years; range: 3-80 years). Syringomyelia was present in 59 patients (41 women, 18 men; average age: 44 years; median age: 47 years; range: 6-80 years) and absent in 31 patients (20 women, 11 men; mean age: 28 years; median age: 29 years; range: 3-65 years).

Results: A mean tonsillar descent of 13 mm was demonstrated in patients with syringomyelia (median descent: 11 mm; range: 5-38 mm) and 16 mm in patients without syringomyelia (median descent: 13 mm; range: 5-67 mm). There was no significant difference in tonsillar ectopia between patients with syringomyelia and patients without syringomyelia (p=0.19). It was interesting to note that the mean age of patients without syringomyelia was considerably lower than that of patients with syringomyelia. This difference was highly significant (p<0.0005). A comparison of CSF flow pulsation amplitudes between patients with and without syringomyelia revealed a highly significant difference between the two groups only in the CSF flow amplitudes in the ventral cervical subarachnoid space (p<0.005) and a significant difference in the region of the thoracic spinal canal (p<0.05).

Conclusions: Our results suggest that age and thus disease duration are major factors influencing the presence or absence of syringomyelia in patients with Chiari I malformation.