Quantitative analysis of cervical CSF and syrinx fluid pulsations.

The author has performed quantitative studies of cerebrospinal fluid (CSF) pulsations in the cervical region in 10 normal subjects and in 13 cases of syringomyelia using a superconducting MRI system. In the normal subjects, the caudally directed CSF flow in the anterior subarachnoid space reached its maximum velocity at 100-200 msec after the R-wave of the ECG. Measured velocities were 26-44 mm/sec at upper cervical levels and 44-124 mm/sec at lower cervical levels. Further small peaks in the caudal direction were seen at approximately 500 msec after the R-wave. Cases of syringomyelia showed lower velocities in the syrinx than in the anterior subarachnoid space, and the movements varied greatly between the cases and levels examined. CSF pulsations in the subarachnoid space were observed in all cases with Chiari malformation. These results suggest that CSF pulsations in the subarachnoid space are transmitted to the syrinx fluid, and that the movements of the syrinx fluid are influenced by various factors.