Hey,
i have the exact same problem. I started seeing the "sparkles" when I was 18 (and am now 21). I've been to a neurologist, eye doc, and several other doctors because I have had other symptoms that came along with it. I was freaking out because when it first started I thought it was a brain tumor or something. However, I do have other symptoms that go along with it, and which all started at the same time the "sparkles" started - hair thinning, ringing of ears, vision worsening, feeling of off-balance, trailers, and floaters. I've had an mri, mra, eeg, and many lab tests and everything came back normal, except for "unidentified white matter" in my brain in the mri. The only explanation the doctors can give me is that my anxiety/stress could be causing the hair loss. I have been known to get anxiety attacks in the past. Does anyone have any advise? Thanks.
Oh, I also see "lightning flashes" every time I go running and my foot hits the ground. Upon impact I get a terrible pound in my head and see "lightning" flash in my peripheral vision.