Pre- and post-operative hydromyelia in spinal dysraphism.

BACKGROUND AND
PURPOSE: There has been limited description of hydromyelia after surgery for spinal dysraphism. The opportunity to compare pre- and post-operative hydromyelia in patients with spinal dysraphism has been possible in two groups of patients using MRI. Post-operative assessment and possible relationship of hydromyelia to clinical findings has been made during a 7- to 14-year period.
METHODS: A total of 38 patients with congenital lumbar or sacral lipomas and 20 with diastematomyelia were studied pre-operatively with a 1.5-T MRI. Most patients in each group were examined with surveillance MRI (1.5 T) post-operatively. Clinical correlations were carried out with each examination.
RESULTS: Of the 38 dorsal or terminal lipoma post-operative patients, hydromyelia increased in 3 and was a new finding in 4. One symptomatic patient in the latter group had extensive septated lumbar hydromyelia. In 8 of 20 diastematomyelia patients, pre-operative hydromyelia was unchanged post-operatively. Hemicord hydromyelia developed in 1.
CONCLUSION: Hydromyelia of varying degree was found in almost one-third of post-operative dorsal or terminal lipoma patients and nearly one-half of diastematomyelia patients. In five post-operative lipoma and two diastematomyelia patients, significant neurological findings remained. One of the six post-operative lipomas had new extensive lumbar hydromyelia that may have been responsible for the patient's symptoms. In the remaining symptomatic patients, hydromyelia was absent or modest.