Chiari 1.5 malformation

Case contributed by Dr Rodrigo Dias Duarte


Patient with headache and dizziness. No other complaints. No trauma.

Patient Data

Age: 30
Gender: Female

Herniation of the cerebellar tonsils through the foramen magnum (about 2.0 cm), including bulb and obex herniation, associated with retroflexion of the odontoid process, with a compressive effect on the bulb, which is reduced in anteroposterior thickness.


See annotations on the image.

Case Discussion

Chiari 1.5 Malformation  is defined as a cerebellar tonsillar hernia (Chiari 1) in addition to some portion of the brainstem through the foramen magnum. It is believed that when congenital, it is the progression of Chiari malformation type 1.

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Case information

rID: 50409
Published: 13th Jan 2017
Last edited: 16th Aug 2019
Inclusion in quiz mode: Included

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