I have had severe headaches now for about 2 years. 18 months ago I went to the doctors because they were getting worse, and was told I would just have to hope that they go away (!). I'm not one to really push things, so I went away and last December went to the opticians instead because they were still getting worse, and by now I was noticing a slight colour difference in my eyes. They said they would refer me back to the doctors for further tests. This apparently took them 4 months because I received a letter this week and had an appointment today.

The doctor said the opticians letter said I had something called 'red de-saturation' in one eye. In the same eye, I have been experiencing twitching at certain points every day for probably 6 months, and it gets worse when I have a headache.
Alongside the twitching, I am having headaches virtually every day, which are worse in the mornings and quite severe, sometimes making me feel sick/nauseous and becoming worse if I bend over or cough. Painkillers don't really make a difference. The pain ranges from sharp and stabbing above my eyes to feeling like there is a huge pressure on top of my head.
I have also noticed in the past couple of weeks that the hearing in my right ear is significantly decreased, it sounds as though everything is muffled as if I am hearing things underwater. My left ear is crystal clear.
Today I had a dizzy spell whilst having a headache.
I hope this isn't too much information but I didn't know what to include or leave out so I'm playing it safe.

Does anybody know what these symptoms could mean? I'm looking for any advice really, because my doctor didn't tell me what any of it could mean, just that she is sending me for a head/brain scan (she didn't give specifics).

What could the scan be for? And does anybody have an idea about the symptoms?

Thanks a lot, I'd appreciate any help anybody could give me

The scan is a diagnostic tool to help them find out what might be and what might not be wrong with you. As far as the symptoms... that's beyond my ability to answer.

I'm a little confused as to whether the red desaturation is in one or both eyes?* I assume it is probably in one eye "unilateral" which is most apt to cause the pain described. The brain scan, as Smoothy noted above, is a diagnostic tool that will allow them to check the optic nerves, optic chiasm and visual cortex amongst other brain regions and pathways. I would imagine they are checking for optic neuropathy, assymetry (difference in size) and lesions. The red desaturation and pain are often associated with unilateral optic neuritis. But that is not a diagnosis, just my idea of why a brain scan is well advised. Following the scan and interpretation of the totality of your symptoms they will probably be in a position to determine a cause and appropriate treatment.

It seems like they have you on the right track even if belatedly.

*Edit. I see you clearly stated it was in only one eye. Should have read more carefully the first time.

Thank you for your responses. DrBill100 - the red desaturation is just in one eye.

I know the brain scan is a diagnostic tool, I was just wondering what could be wrong because the doctor didn't say anything. Thanks for the advice DrBill, it's good just to have a clue what is going on with my body!