migraine aura visual disturbance does anyone else get this?

I realised something about my visual disturbances over the last week and wondered if anyone else gets this or if it is a sign of something else.

I get two sort of stages in the disturbances, the first being copying lighter objects that develop into crosshatching. (They move rapidly and make it feel like someone or lots of pepople are moving in front of me)The second phase seems to be black glitter and more zigzag snakes that are seethrough that can develop into balckout patches that can take the vision in one eye.

OK so in the first phase which I start the day with every single day, I realised that if I have been dreaming when I wake I have a sense of the things in my dream in with the visual disturbance. I wasn't sure about this, so I closed my eyes and imagined a different place, my mums sitting room to be exact. When I stoped imagining the room and looked in front of me, the light areas from the sittingroom, which are very different from my home, became part of the light copying that dissintigrates into the hatching effect.

I also noticed that the visual disturbances increase when I put the wall heater fan on in the bathroom.

I do not regularly get pain with these symptoms. So what I am asking really is, do you get this kind of effect or is this nothing to do with migraine and I should be banging on the door of an eye hospital?

regards

Di

Wow Di - You're dealing with some pretty interesting phenomena there! ((hugs)) I get nothing like this. I can't say if it's part of your migraine or not. If migraine is hyperexcitability of neurons in a particular area of the brain could this happen? I don't know. If it's spreading neural depression could this happen? I don't know. I wish I knew more!! Here's what I think I know tho:

When you close your eyes and imagine a scene, the same neurons in your occipital (visual) cortex (at the back of your head) activate as if you were seeing the thing for real. That has been investigated through fMRI research - the same areas of your brain light up whether you're imagining it or seeing it for real. This totally bypasses your eyes of course - so there's nothing going on in your eyes. It's very likely it's all happening in your occipital cortex. The left occipital cortex will affect the right visual field of both eyes - that's the right 50% of your sight in both eyes. The right occipital lobe will affect the left visual field of both eyes.

Your visual cortex is very highly specialised - you have neurons that react to vertical lines, slanted lines, etc. Your brain puts it all together to create what you see. When something is going wrong with either the neurons that respond to the very specific component parts of perception, or the higher level processing which puts it all together, you're going to wind up with disturbed vision. And all of this has nothing to do with your eyes.

What I find interesting though (only because I don't know enough to understand the neurology) is that you seem to be getting a one to one inhibitory response the same as you would as if the light from your imagined room was falling on your retina in your eye. Cells on the retina get 'tired' and are slower to respond once they've been swamped by some light for a bit - that's why you get those retinal darkspots if you look at a bright light, or whatever. Since only researchers in highly controlled experiments using (poor) monkey's and electrodes can study the primary visual cortex in detail, I don't know what the inhibitory timeframes are for imagined visual scenes on visual neurons. When I say inhibitory timeframes I mean - the time that the neuron is 'tired' and doesn't respond again.

I recommend that you find a neurologist who specialises in primary visual disturbances and get an opinion on whether you have a migraine or if you have something else going on in there. It's very interesting that your visualisation can disturb your neurons to such an extent that you get the light copying/crosshatching effect when you open your eyes.

DISCLAIMER: I'm basing this on my 4th year uni understanding of the visual cortex which i've only studied in detail in 1 subject. That means I don't actually know what I'm talking about but find it all very interesting!

EDIT: the positive thing about this is that if you find an expert and draw the effect for him/her - they should be able to tell you what is happening BECAUSE the visual cortex is so well studied and so highly specialised. That's a positive.

Best of luck with it.

wow that's an informed post! Thanks for explaining some of this stuff to me. These lights or whatever they are have been driving me crazy.
regards

Di