The Complex Chiari

The complex has been described as Chiari that also involves the brainstem being herniated but in the absence of the other Chiari 2 features (myelomeningocele). 


Other features reported in Complex Chiari are:


- Retroflexed Odontoid/Medullary Kink

- Abnormal Clivoaxial angle

- Basilar Invagination


The literature currently supports that additional treatment beyond the standard Chiari Decompression Surgery is required. This may include occipital-cervical fusion and/or transoral odontoidectomy.


See our page for craniocervical instability. However, this is still controversial with no consensus between doctors. 



However, this presentation of a chiari type is still fairly new and still gaining support worldwide. Some doctors believe that with the improvements in MRI's that this is not a new type of chiari, but just an expected variation of Chiari Type 1. 



Doug Brockmeyer Neurol Sci 32 (S345-347) 2011

Robert Bollo J NSGY Ped 10(2): 134-141, 2012





Complex CHiari