Unfortunately I don’t have enough experience in this area of the anatomy, to pass comment, sorry.
I travelled across the Atlantic to The Chiari Institute in 2008, in fact they confirmed my Cranio-cervical instability (CCI). They wrote a paper on how to determine CCI in Dec 2007. There’s a link to it somewhere on this website. They are an extremely knowledgeable bunch of people, especially Dr B, who’s amazing and a great educator. Have you watched the video’s on their website ? I spent days and days watching them and I gleaned an awful lot of very useful information from them.
Their method requires you to have nead/neck MRI’s in ‘flexion’ (head down), ‘neutral’ (straight up) and ‘extension’ (head back) positions. You then have to consider various angles and measurements, to assess whether it’s normal, or whether there’s CCI. Although it appears complex upon first reading, I managed to teach myself the method, so a radiologist should be able to pick it up, if they were instructed to do so.
Surgery has to be a last resort, so really you need to see if you can alleviate your problems by other means first. If you do have a collagen issue, it will be helpful if you can increase your protein intake, eat more eggs, fish, meat or poultry, especially eat the chicken skin and get as much proper chicken stock down you as you can. Also, eat vitamin C foods regularly throughout the day (fruit and veg, especially green leafy veg, red peppers, etc) or take supplements – but foods are always best. The magnesium absorbed from an epsom salts bath, can help the body to start to pick up in many ways, especially easing intracranial symptoms.