Chiari malformation. Follow-up of cervical spine T2 hyperintensity (syrinx). Brain:Changes of Chiari I malformation have not changed since the previous examination. The cerebellar tonsils are pointed and descend up to 23 mm below the level of foramen magnum (upper C2 level). This is associated with severe crowding of the CSF space/cisterns at the level of foramen magnum. This is associated with severely diminished pulsatile CSF flow across the foramen magnum, which is worse posteriorly. There is no contrast enhancing brain lesion.The remainder of the brain shows normal signal and morphology. The mastoid air cells are clear. There is minimal maxillary and sphenoid mucosal thickening. The orbits are unremarkable.Cervical Spine:The poorly defined, T2-hyperintense, T1-hypointense signal involving the posterior central cervical spinal cord at lower C2 level has not changed since the previous examination. This is not associated with discrete cavitation. This probably represents a presyrinx rather than a developed syrinx.The cervical spine is also notable for retroflexed dens which contributes to the compression at the level of foramen magnum. The remainder of the cervical examination is normal. Alignment is anatomic accounting for straightening which may reflect patient position. Vertebral bodies are preserved in height. Intervertebral discs are preserved in height and T2 signal. The spinal canal is not narrowed nor the neural foramina.
1.No significant change in findings of Chiari I malformation including descent of peglike cerebellar tonsils to the level of C2. Retroflexed dens also contributes to the stenosis at the level of foramen magnum.2.Ill-defined defined mild T1-hypointense and T2 hyperintense signal without discrete cavitation in the cervical spinal cord at C2 level is compatible with presyrinx and has not changed since May 2015.