Chiari malformation: autism. Brain: The cerebellar tonsils extend up to approximately 6 mm inferior to the foramen magnum, but display rounded to minimally pointed morphologies. There is flow of cerebrospinal fluid across the foramen magnum, albeit slightly blunted posteriorly. There is no evidence of intracranial hemorrhage, mass, or acute infarct. The brain parenchyma and pituitary gland appear unremarkable. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.Cervical Spine: The vertebral column alignment is within normal limits. The vertebral body and disc space heights are preserved. The vertebral bone marrow signal is unremarkable. There is no significant spinal canal stenosis. The spinal cord displays normal signal and morphology. The paravertebral soft tissues are unremarkable.
1. Low-lying cerebellar tonsils may represent a mild form of Chiari type 1 malformation.2. No evidence of syringohydromyelia in the cervical spine. 