Abstract
We report a case of syringomyelia in which the size of the syrinx reexpanded following foramen magnum decompression. The patient, a 15-year-old male, was admitted to our hospital because of numbness and spontaneous pain of the left upper limb. Since MRI revealed Chiari type I malformation and syringomyelia, we performed C1 laminectomy and foramen magnum decompression that only opened the external dural layer. Three days postoperatively, his neurological findings improved, and the syrinx had reduced in size. However, at 3 months postoperatively, numbness in his left upper limb recurred and the syrinx reexpanded. We carefully monitored his neurological symptoms and, at 5 months postoperatively, the syrinx once again reduced in size. Previously, no report has indicated that the size of the syrinx can change after foramen magnum decompres-sion, and the mechanism that causes this is unknown. However, it should be kept in mind that the size of syrinx can fluctuate after foramen magnum decompression.
