Chiari 1.5 malformation

Case contributed by Rodrigo Dias Duarte
Diagnosis certain


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.


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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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