Progressive severe headache. BRAIN:The left cerebellar tonsil is elongated/peg-shaped and extends up to 2.8 cm below the level of the foramen magnum, to upper C3 level. It causes mild deformity of the caudal medulla and upper cervical spinal cord, which is more eccentric to the right within the spinal canal. There is faint T2STIR hyperintensity within the upper cervical cord at the C2-C3 level on sagittal and perhaps axial imaging which may reflect soft syrinx. The right cerebellar tonsil barely extends below the level of the foramen magnum. The fourth ventricle is normal size and there is no hydrocephalus. Overall volume of the posterior fossa is normal and the cerebellum is otherwise normal in morphology. Myelination is appropriate for age. There is no midline shift. A focal 10-mm CSF-intensity structure along the superior surface of the anterior edge of the tentorium cerebelli (vs adjacent to and extending through a small dural defect) which may represent a small arachnoid cyst. There is no abnormal intracranial contrast enhancement. Major intracranial vascular flow voids are preserved. There is minimal ethmoid mucosal thickening. A 4 mm fluid intensity within the pineal region is probably a small cyst, of doubtful significance. The adenoids, tonsils and retropharyngeal lymph nodes are prominent, which is a common incidental finding in this age group.The CSF study was performed at the mid sagittal plane. Dorsally, the flow signal is significantly attenuated with loss of synchronicity compared to the ventral flow. Ventrally, there is focal attenuation of the flow at the level of the most severe narrowing at C1 level but preserved biphasic flow cranial and caudal to this otherwise. WHOLE SPINE:There is a multiloculated lower cervical syrinx that is 3.0 cm craniocaudally extending from C4-C5 level to C7-T1 level which measures transaxially 7 mm x 6 mm. Two other smaller focal dilatations of the central canal are present at the upper and lower T4 levels. In addition, there is the faint T2-hyperintensity within the upper cervical cord at C2-C3 level described above, which may reflect pre/soft-syrinx.The spinal cord is otherwise unremarkable. The tip of the conus medullaris lies at L1-L2 level which is normal. The spinal canal is also preserved. The vertebral bodies are preserved in signal and morphology. The intervertebral discs are also unremarkable. Note, there are no post contrast images through the lower thoracic/lumbar spine. There is no abnormal contrast enhancement in the region of the syrinx.
1.Chiari 1 malformation, more pronounced on the left side. No hydrocephalus or other posterior fossa malformation. CSF flow study is remarkable for marked dorsal attenuation and loss of phasic synchronicity between the ventral and dorsal flow.2.Resultant lower cervical syrinx and smaller upper thoracic syrinxes are present as described above. Faint increased T2 signal in the upper cervical spinal cord at C2-C3 level may represent soft syrinx, but can be followed on the subsequent exams.3.Focal 10-mm CSF-intensity structure along the superior surface of the anterior edge of the tentorium cerebelli (vs adjacent to small dural defect) which may represent a small arachnoid cyst.