6 years, Male, Chiari malformation. Yearly follow-up. The cerebellar tonsils are caudally displaced measuring up to 17 mm below the foramen magnum and demonstrate a peglike configuration. Tonsils terminate just inferior to the C1 posterior arch, previously extending to the mid C2 level. There is retroflexion of the dens which contributes to effacement of the ventral thecal sac. There is overall mild crowding at the foramen magnum, which is improved since prior. Sagittal midline CSF flow sequence demonstrates minimally diminished but otherwise preserved biphasic flow ventrally and dorsally through the foramen magnum, as well as into the fourth ventricle.Brain parenchyma is otherwise unremarkable. No evidence of infarct, hemorrhage, mass, or mass effect. Ventricles are normal in size. No extra-axial collections. Sulcation and myelination are unremarkable. Bone marrow signal and extracranial soft tissues are grossly unremarkable.Evaluation of the cervical spine demonstrates no cord signal abnormality or evidence of syrinx. Vertebral body heights and intervertebral discs are unremarkable. Bone marrow signal is unremarkable. No significant spinal canal or neural foraminal stenosis is seen. Paraspinous soft tissues are unremarkable.
1. Findings consistent with Chiari I malformation are again seen. Cerebellar tonsillar descent has improved since prior from 1/30/2015 as has the associated crowding at the foramen magnum. There is mild crowding on the current study and minimally diminished biphasic flow of CSF.2. No evidence of syrinx in the cervical cord.