Chiari Malformation

I'm hoping to start this discussion in hopes we can all learn something. A client of mine has Chiari Malformation.

Chiari Malformation:

A chiari malformation is a medical condition where the brain stem herniates into the spine. It is either congential - meaning you were born with it, or it is acquired, which means it developed due to other reasons, and over time. (source: empowher.com)

Symptoms: dizziness, numbness, foggy vision, and foggy mind, terrible headaches.

My client loves to work out, loves Pilates,she's a great student. She wishes to continue Pilates, and has her doctors consent. However I need to make sure that all the exercises we do don't add too much pressure to her back and neck.

Does anyone have experience with this special case? What should I avoid, what can I add to her workout that still makes it fun and interesting for her?

I'm very open to any suggestions