Study Design: Non-randomised case controlled study.

Objectives: To study the relationship of CSF flow abnormality and severity of cervical spondylotic myelopathy.

Subjects: 45 consecutive patients undergoing MRI examination of the cervical spine. CSF flow measurement in the cervical spinal canal were done with phase contrast MRI in 3 subject groups consisting of 7 patients with clinical myelopathy, 8 patients with subjective myelopathy and 30 control subjects with no myelopathy. Modified JOAS scores and clinical examination findings were used to assess the severity of myelopathy. All subjects were imaged on 1.5 T Philips Magnetic Resonance scanner. A retrospective gated, phase contrast sequence was used to measure flow velocity for 15 time points in the cardiac cycle. Measurements were taken at the level of C2, above and below the levels of spinal stenosis.

Outcome Measures: Mean and Peak CSF flow velocity and caudal CSF flow was recorded at all the three levels. Differences in means were tested with one way ANOVA.

Results: Inter-group comparison showed both mean and peak CSF flow to be significantly lower in the clinical myelopathy group at above and below the stenosis but there was no difference at the level of C2. Patients with subjective myelopathy had lower range of mean and peak flow compared to the control group, but this was only significant for mean flow above the block (p< 0.05). There was significant difference between the caudal CSF flow per cardiac cycle between the groups at all the 3 levels.

Conclusions: The results suggest that a disturbance of pulsatile CSF flow in the cervical canal has high correlation with clinical myelopathy. Further study in a larger patient group would be needed to see the effect in a subjective myelopathy group.