Chiari 1 malformation with focal syrinx

Case contributed by Assoc Prof Frank Gaillard

Patient Data

Age: 30 years
Gender: Female

MRI brain


Annotated image

Measurement of Chiari 1

Diagram and annotated image of how to measure tonsilar descent. A line (dotted blue) is drawn on the midline sagittal plane across the inner margins foramen magnum (ophisthion to basion), and measuring the inferior most part of the tonsils (green arrows). The tonsils normally protrude through foramen magnum by no more than 5 mm.


MRI cervical cord

MRI of the cervical spine with contrast demonstrates a focal cystic dilatation in the center of the cord behind C2. There is some additional high T2 signal extending inferiorly. There is no solid component or evidence of contrast enhancement. 


Post-op MRI

Posterior fossa decompressive craniectomy and resection of the posterior arch of C1 is again demonstrated. There has been reduction in the size of the focal syrinx at the level of C2. 

Case Discussion

This case illustrates a Chiari 1 malformation complicated by a focal syrinx in the upper cervical cord. The patient was treated with a posterior fossa / C1 decompression which resulted in both radiological and symptomatic improvement. 

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Case information

rID: 15819
Published: 14th Nov 2011
Last edited: 7th Oct 2019
Inclusion in quiz mode: Included

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