Presentation
Headache and vertigo.
Patient Data
Caudal descent of the cerebellar tonsils through the foramen magnum 13 mm below the McRae line on sagittal sequences with associated caudal displacement of the medulla and posterior angulation of the odontoid process. No associated hydrocephalus.
No associated syrinx of the cervical cord on the sagittal T2 sequence.
Case Discussion
MRI features of Chiari 1.5 malformation with no syrinx of the cervical spinal cord.
Chiari 1.5 malformation is defined as a combination of cerebellar tonsillar herniation (as seen in Chiari I malformation) along with caudal herniation of some portion of the brainstem (often obex of the medulla oblongata) through the foramen magnum. It is considered a progression of Chiari I malformation.
Unable to process the form. Check for errors and try again.