 Brain: There are postoperative findings related to Chiari decompression. There are foci of deformity of the posteroinferior aspect of the cerebellum, with tenting towards the overlying dura. There is a retroflexed dens with associated narrowing of the column of cerebrospinal fluid flow across the anterior neo-foramen magnum. Cerebrospinal fluid flow across the posterior neo-foramen magnum appears to be intact. There is no evidence of acute infarction or hemorrhage. There is mild scattered paranasal sinus mucosal thickening.Spine: There has been interval decrease in size of the thoracic syrinx, which now measures up to 1 mm in width, previously 6 mm. The vertebral bone marrow signal is within the normal limits. There is lack of the usual cervical lordosis, but no spondylolisthesis. There is normal alignment of the lumbar vertebral bodies. The vertebral bone marrow signal appears unremarkable. The conus medullaris is located at the level of L1. The filum terminale appears unremarkable. There is no evidence of spinal canal or neural foraminal stenosis. The paraspinal soft tissues are unremarkable.
1. Postoperative findings related to Chiari decompression. A retroflexed dens is associated narrowing of the column of cerebrospinal fluid flow across the anterior neo-foramen magnum and tenting of cerebellar tissue towards the overlying dura may indicate adhesion formation. 2. Marked interval decrease in size of the thoracic syrinx.