Sinus congestion helped by neck stretches - how to understand this?

As I have written earlier on curezone, I suffer from a feeling of heaviness and stiffness around my eyes, mostly my left eye. It has been a year since this began, although I had it in a significantly milder form before too. It disables me from proper social contact and also in my work because I am unable to make proper eye contact, as my eyes stiffen into a gaze.

I know that sinus congestion is related to this because I can breath easier from my left nostril rather than my right. However, I have tried many remedies for sinus and not had anything more than temporary relief.

What I have discovered over the months is that when I stretch my neck, my sinus clears up for a few moments. The stretch I do is among the most simple ones. It can be seen in the image on this page.

http://brockvillemassage.com/stretch-your-neck/

I don't quite understand what is happening here. My physiotherapist says that the brain gets certain signals and it could be that in my brain's make-up, the areas that are stimulated when the neck muscles stretch are also the areas that are stimulated when the sinuses clear, and that the brain is far too complex and too little understood at this time to offer any simple explanations. He said it with a little more jargon but this was the essence of it.

Can anyone help me understand what is going on here? How do neck stretches help the sinuses? I have been asked by the doctor to get an MRI of both the cervical spine and the sinuses but having read up on MRIs I do not feel it is safe to get them. Tweet