Replied by D.m.linn (Usa) on 07/23/2016
Hope this will help, not sure if this relates to your problem, but it might........about ten years ago I was using a lubricated eye drop for my dry eyes, that contained cellulose. For months I was expierencing sharp pains in my head, the pain came out of the blue, and lasted seconds, it was like lightning strikes. I, of course thought I could have a brain tumor. I discovered without the help of my doctor, that it was from the eyes drops. Since then I have been using lubricant eye drops that are preservative free. I now stay away from anything that contains cellulose and also pectin, that includes many vitamin and supplements. And I'm very careful not to eat any processed foods that contain preservatives. Good luck.