hi.. I also have a congenital fusion of C 5-6..i found out when i was 13 and dislocated my shoulder. They had told me then when i was older i would probably need surgery, well that was 30 years ago lol. I have had problems off and on all my life with neck pain, having to be careful what i did or lifted, cause i knew i would pay the next day. And the headaches..omg they are so bad, anyone else get the bad headaches?? Just recently i couldnt handle the headaches anymore and nothing was working for the pain, so my pcp ordered a mri. well results are in, i also have disk herniation at C4-5 with severe right foraminal narrowing, also at C3-4 i have spondylosos with right and left moderate foramonal narrowing...hmmm explains the bad shoulder and arm pain ive been having the past 3 weeks. this is the first i heard of that symdrome, keplers?? im gonna look into it...any advice on this would be great from anyone...the doctor i seen 30 years ago said only 1 in like 10 million have the congenital defect i have, i am so glad to have found someone that does...i go to neurosurgeon next week wish me luck.