 Brain: Again seen are findings of Chiari 2 malformation with herniation of the cerebellar tonsils which lie at the lower C3 level. There are findings of sub-occipital decompression. A 4th ventricular catheter is unchanged in position. A stable left parietal approach ventriculostomy catheter terminates near the midline. The 4th ventricle measures minimally larger in the AP dimension at 5 mm compared to 3-4 mm on examination from 6/30/2015 and 4 to 5 mm on 12/16/2014. The subtle differences may be related to differences in slice position. The lateral and third ventricles are also not significantly changed in size compared to recent CT and MRI studies. There is stable mild T2 hyperintensity adjacent to the occipital horns. No abnormal parenchymal or meningeal enhancement is appreciated. There is dysgenesis of the corpus collosum with absent posterior body and splenium. Again seen is enlargement of the CSF space anterior to the brainstem with clival scalloping raising possibility of arachnoid cyst but unchanged. There is no evidence of intracranial hemorrhage, mass, or acute infarct. There is unchanged prominence of the distal right internal carotid artery. Calvarium and extra cranial soft tissues are grossly unremarkable.Spine:There is syringohydromyelia which begins at the C3 level and extends inferiorly through the entire length of the spinal cord. It is unchanged in size and measures up to 4 mm in the AP dimension at the C7 level. There is significant thinning of the surrounding cervical cord parenchyma.Syrinx in the thoracic cord is similar, measuring 8x8 mm at the T4 level, previously 8x9 mm. At T6, syrinx measures 7 x 7 mm, previously 8 x 8 mm. There is severe mid-thoracic dextroscoliosis. There are posterior disc protrusions at C4-C5, C5-C6 and relatively worst at the C6-C7 where there is indentation of the spinal cord similar to prior. Dorsal thecal sac is widely patent at these levels. Enhancement of the paraspinous soft tissues is consistent with postsurgical change.Again seen is evidence of prior lumbosacral myelomeningocele repair with small stable pseudomeningocele. The distal neural placode is located along the dorsal aspect of the thecal sac and terminates at approximately the L5 level. No significant ventral motion of the distal neural tissue on the prone sequences.There is unchanged angulation of the coccyx. The vertebral body and disc space heights are preserved. The vertebral bone marrow signal is unremarkable. The paravertebral soft tissues are grossly unremarkable.
1. Again seen are findings related to Chiari II malformation status post decompression, VP shunt placement, fourth ventricular stent placement, as well as lumbar myelomeningocele repair. There is overall no significant change in caliber of the ventricular system or syringohydromyelia extending the length of the spinal cord. There are minimal differences in measurement as noted above. No abnormal parenchymal or meningeal enhancement in the brain or spine is appreciated.2. There is no significant change in appearance of distal cord and conus with no significant ventral motion on the prone sequences. Finding raise possibility of cord re-tethering in the appropriate clinical setting.3. Unchanged dilated caliber of the distal right internal carotid artery suspicious for aneurysm for which an MRA is recommended for further characterization. 