MRI follow-up in syringomyelia. Observations from twelve cases.

In 12 patients syringomyelia was diagnosed using MRI. The underlying cause was a hindbrain hernia in 8 patients, a posterior fossa cyst in one case, and in 3 patients the underlying cause remained unknown. Syringo-subarachnoid shunting in 8 patients failed to decrease pain and the size of the syrinx, motor lesion and gait disturbance in the majority of patients. A cysto-peritoneal shunt in the patient with a posterior fossa cyst and a syringo-peritoneal shunt resulted in a decreasing syrinx and clinical improvement.