Chiari Online Support Group

Amount of deviation


Is there anyone here who has had decompression surgery or having the surgery in the future that would mind sharing with me the size of their deviation. Mine is mild but I’ve read that minor deviations can sometimes cause more symptoms than a larger deviation. I was also wondering if the size of the deviation was a definite deciding factor in rather surgery is performed or not. I have read so much conflicting information I don’t even know what to think anymore lol.



Hey Terra,
“I have read so much conflicting information I don’t even know what to think anymore” I notice you have ‘lol’ and the end of that sentence but I haven’t included it because as far as I’m concerned its not very ‘lol’ at all. The net is a great place to get information but as you have found it can be so confusing, and I’m sorry to say that the same goes for dr’s. What one dr may see as minimal another may see as major.
Dr’s are scientists. In science A+B=C, Cause ‘A’ + Symptom ‘B’ = Diagnosis ‘C’. In physics and chemistry A+B=C works, but in biology it is not as black and white, there can be 1000’s of variables, for example environmental factors, physiological factors etc all have an impact so its not a case of just A+B but more A+B+C+D+… and neurology is biological. To add to the complexity of it all, no two brains are wired in exactly the same way. An individual can have pressure in exactly the same place as another but have vastly differing sensation. For example, a back injury can seem minimal for one person but debilitating for another and this can be an example of where A+B does not always =C. It can also depend on which nerves are affected, if its the nerve to the big toe then the physical consequences can be minimal, but if its a nerve to the heart that could be deadly. So again the theory of A+B=C is not always correct, there are many variables.
I do not have chiari, but I do have a brain condition that has caused a deviation of the brain matter and I find it rather confronting when a dr says things like “Well that shouldn’t be happening…” or “…you shouldn’t be having pain like that…” and I agree, I shouldn’t, but I am. So my question to them is “So what are we going to do about it?” Many may recommend a ‘wait and monitor’ scenario, like ‘Let’s see what happens’ But if there is any change, any ‘weird sensations’ record it, tell them. I have had dr’s ignore symptoms, but when I’ve later spoken to the surgeon and explained to them they have been extremely concerned. Each and every dr I have seen has had a differing opinion, so, IMO, do not be taking an individual dr’s opinion as gospel. It is never a bad idea to get a second opinion.

Best of luck with it all

Merl from the Moderator Support Team


Thank you for your reply. Just to let you know the “lol” isn’t to make light or make fun of the situation. Just kinda at a point where it’s laugh or cry and sometimes do the both simultaneously because this has been a long frustrating journey and I’m just getting started on it good. I’m sure many can relate. Thanks


No problem. I completely comprehend “…a point where it’s laugh or cry and sometimes do the both simultaneously because this has been a long frustrating journey…” and I can assure you when it comes to neurology that point is a common destination. I have been there too and that’s why I say ‘Not very lol at all’. I was stressed to the almighty and then to have dr’s ignore or minimise my symptoms just added to my stress.
So, yes, many can relate I’m sure.

Merl from the Moderator Support Team


Hi - I had decompression surgery 3 years ago. My deviation is 19mm. My main symptoms before surgery were the headaches, pain in my neck/shoulders, and tingling down my left arm (all are gone now). :slight_smile: My decision to proceed with surgery was the severity of my symptoms, and my NS said that if I didn’t have the surgery I could have irreversible nerve damage. My recovery was hard but if I had it to do over again, I would have the surgery. Best of luck to you.


Thank you!


My herniation was 7mm and I had flow voids posterior (no blood flow at back of brain.) My symptoms were motor control weakness and loss of coordination, vision disturbance, syncope, pain, and what are referred to as shut down episodes. The flow voids were a deciding factor and after the decompression surgery I found that my brain stem had also been compromised.
My life significantly improved and I agree with Susie, if I had to do it over again, I would have the surgery. Recuperation is per individual and it took 6 weeks before I went back to work (single-grown children-close family to help.)
A key is to not overdue physically. The portion of the brain compromised is the portion that provides motor control and it will always have its issues; the surgery is not a cure.
You did well to reach out and seek advice from people who have been down this road; I wish I had, but it took 9 years before I did.
Best always.


Thank you for replying! I have a lot of pain, mainly in my neck and back. Tension, pins and needles, burning etc. I can’t lay on the back of my head, Terrible headache/migranes, long lasting and short lived from different things like coughing or exercise. I am working very hard to find neurologist and neurosurgeons that can help. My current neurologist told me that it could be causing my symptoms but he could not say 100%. So, I’m just working on what to do next. I’m glad you have recovered well. Each of you that I have spoke with will help make my decision easier if I am recommended for surgery.