Degenerative Disc Disease common with Chiari?

I have suffered from DDD for years and I am wondering if Chiari worsens it, causes it or has nothing to do with it. I am just trying to wrap my head around all of this and see if I can just figure it all out. How many of you suffer from DDD???

I have DDD in cervical and Thoracic spine and so far have had ACDF at C-5,6,7 and 2 syrinx's in thoracic spinal cord. No clue if any connection. Sorry I'm just learning about all of this to