Cervical-thoracic syrinx to T11 with growth. There are stable postoperative findings related to posterior fossa decompression and C1 laminectomy. The cerebellar tonsils remain low-lying and pointed in configuration. However, there is interval decrease in the extent and caliber of the cervicothoracic syringohydromyelia, measuring up to 4 x 9 mm in cross section, previously 8 x 12 mm. The cerebellar tonsils are stable in position and configuration. There is intact flow of CSF across the anterior foramen magnum, but relative paucity of flow across the posterior foramen magnum, which is unchanged. The vertebral column alignment is unchanged. There is no significant spinal canal stenosis. The vertebral body heights and disc spaces are intact. There paraspinal soft tissues are unchanged. There is unchanged diffuse mild prominence of the thyroid gland.
1.Stable postoperative changes of Chiari decompression since prior study with intact CSF flow across the foramen magnum anteriorly, but negligible CSF flow posteriorly. 2.Stable cervicothoracic syringohydromyelia that extends from the level of C2-3 to T9-T10, measuring up to 2 x 4 mm in cross section. 