20mm is a lot. Both syrinx and hydro are probably related. So for you I guess there is no other option as to go for it. You can even die from the condition progressed this way.
I sent you a PM (private message)
The biggest issue is having a CSF obstruction....at this point once you have a syrinx that is the bigger concern as it can grow larger and compress the nerves this can lead to paralysis...
With the tonsils they can get very long but if they are thin the length makes no difference....it is the width that is more important....
Another concern is if you could have a retroflexed odontoid as it can cause more constriction to the area....
So at this point it is the syrinx and CSF flow that you need to focus on....
And if you have any other related conditions like EDS, POTS< ICP, sleep apnea, disk issues, tethered cord....as they can affect how you feel and heal post op.
Thank you for your response. Yes, I do have an obstruction of CSF flow, and syringomylia. It took the doc's so long to diagnose me, that I honestly don't know what diagnosis came first, I was only 12 years old when I was diagnosed properly. But, because of an immune deficiency that I was born with, there wasn't a doctor willing to do the decompression surgery. I am now going to see Dr. Heffez, and he is interested in my unique case. I was told by a different doctor (not Dr. Heffez) that if I didn't get the decompression surgery, I could become quadriplegic without the surgery, because the herniation has grown from 5mm-20mm in the last 10 years. Do you know how far the tonsils can herniate before it stops or causes major problems? You are obviously much more versed on the subject than I am. Thank you again for your time and help!
https://www.inkling.com/read/fenichel-clinical-pediatric-neurology-pina-7th/chapter-12/spinal-paraplegia-and
Hi...I do not think becoming a quadriplegic is a side effect of Chiari....but can be an issue to those with brain stem compression and syringomyelia.
Since you have hydro, do you know if you have an obstruction of CSF flow due to the herniated cerebral tonsils?
Did you have the hydro b4 or after your Chiari was DX'd?