 MRI brain: There is inferior descent of the cerebellar tonsils up to 11 mm below the foramen magnum compatible with Chiari I malformation. There is diminished CSF space at the level of foramen magnum, worse posteriorly.CSF flow sequence is technically limited and direction of the flow cannot be evaluated. Magnitude images demonstrate mildly diminished CSF flow ventrally and more severe diminished flow dorsally.There is no diffusion abnormality. There are no areas of abnormal signal. The ventricles and sulci are within normal limits. There is no hydrocephalus. The basal cisterns remain patent. There is no midline shift or mass effect. No extra-axial fluid collection is identified. Normal flow-voids are demonstrated in the major intracranial vascular structures. There is minimal opacification of the paranasal sinuses. MRI spine: There is a large cervical syrinx which begins at the upper C4 level and more inferiorly occupies nearly the entire diameter of the cervical cord, measuring approximately 11 x 9 mm in the axial plane at the C6 level. There is further extension of the syrinx down to the thoracic cord at the lower T12 level.Conus terminates normally at the upper L2 level. There is no evidence of filar lipoma or other lesions within the lumbar spinal canal. On prone sagittal imaging, there appears to be minimal ventral motion of the conus, approximately 1 mm; however, there is greater ventral motion of the cauda equina about 4 mm at the L3 level. The apparent reduced ventral motion of the conus is of questionable significance given the normal position of the conus, appropriate ventral motion of the cauda equina nerve roots, and absence of additional lesions in the lumbar spinal canal.The spine is in normal alignment. The vertebral body and disk heights are well-maintained. No worrisome focal marrow signal abnormality is appreciated. There is no significant spinal canal or foraminal stenosis within the spine at any levels. The paraspinal soft tissue structures are unremarkable.
1. Inferior descent of the cerebellar tonsils of up to 11 mm below the foramen magnum consistent with Chiari I malformation. 2. Extensive syringohydromyelia involving the cervical and thoracic spinal cord extending from upper C4 to the lower T12 vertebral levels.3. No convincing imaging evidence of tethered cord. Please see comment above.