This sounds very much like the description of an ocular migraine (which I get too, although rarely now).
That’s exactly the way my ocular migraines play out too – suddenly blind in the dead center of my vision, then slowly the dot of blindness expands to a ring of blindness that gradually covers my entire field of vision except the very outer periphery, and then I can see again.
That was scary as hell the first time it happened.
I had an operation about two years ago; nothing to do with my brain or anything, but for two weeks following the op I had two or three migraines with aura per day. Doctors had no idea why this was happening, and I was getting very scared that I was going to be stuck with this condition for life.
But they abruptly stopped and I haven’t had a migraine since 
I got them as a high school student (although more of a “migraine with aura,” as it wasn’t just the visual distortion but also crushing headache and nausea) then more infrequently as an adult. Didn’t have them for many years, and then had three ocular migraines during my first week at a new job. (I presume there’s a stress trigger.)
I’ve been using insulin for the past year. I inject once a day about an hour before bed time. The insulin peaks after about 1-3 hours and then tapers off during the next 20 hours.
I monitor my blood sugar throughout the day. Based on a number of factors such as recent fasting levels, amount of recent exercise and others, I adjust my insulin by about 10% up or down.
On a couple of occaisions, I missed the target and experienced hypoglycemia. Both times the onset was about an hour after my injection while I’ve been reading in bed.
It starts with a light headedness, elevated heart rate, dilated pupils to the extent I can’t focus on anything, profuse sweating and light panic.
I’m fortunate I can sense the onset of symptoms and recognize what I need to do. Some people can’t.
Treatment is as easy as ingesting some sugary carbs. Most symptoms start to resolve after a few minutes. Things are normal again after about 45 minutes.
It’s happened twice. I’m very concious of the idea it could happen at less convenient times. I usually check my blood glucose before driving and keep a supply of glucose pills within reach at all times.
Had a seizure in the hospital two weeks ago due to an electrolyte imbalance (or rather, severe lack of. which they were desperately trying to replenish). I don’t remember any of it, just that I came to my senses while they were rolling the hospital bed back to my room. I’m still on an anti seizure med but I’m tapering off of it. Nothing is wrong with my brain thankfully.
We had a thread some time ago about Alice in Wonderland Syndrome, which I used to get when I was a kid.
I had a strange attack of vertigo once, when I was about 25… I had just gone from my office into the corridor, and all of a sudden “down” shifted 90 degrees – like in that Fred Astaire clip where he starts dancing on the wall. I instinctively slammed myself into the wall that was “down” – and then a second later, everything was normal again.
Occasionally there are times, when I’m falling asleep, that I am partly asleep but still conscious. Sometimes I’ve noticed that I lose my sense of touch – for example, I can’t feel my fingers. Other times my thoughts turn into visual images, like slipping into and out of a momentary dream. Rarely, I’ve had auditory hallucinations… like, I’ll be drifting off, and I’ll hear some kind of noise that wakes me back up, and the pattern will repeat until I realize that the noise isn’t real.
One phenomenon I’ve always enjoyed is what I might call “feeling memory”. When I’m in the right frame of mind, these feelings will sort of spontaneously bubble up out of my unconscious; they feel like I’m remembering something, but I don’t know what… the actual experience is that of feeling some complex, ineffable emotion, with a sense of it coming from somewhere in my past, but without being able to identify what it’s associated with. It’s a little like presque vu. Usually it’s very pleasant, but there was one time, about ten years ago, when it started up and would not stop… for a period of several hours, everything I looked at or thought of was causing these emotional reverberations… fortunately it went away by itself.
When I was 21 (half my life ago!) I had a job where I filled in work orders for office equipment with what the technician dictated over the phone. I had a slight headache, but nothing unusual. I was talking to one of my guys and he was giving part numbers and I was looking at my hands resting on the keyboard, trying to will them to type. I said to my neighbour “I can’t make my hands do what my brain wants them to do…” and she called the boss over, who called my husband to come and get me and take me to the ER. While I was waiting for him I tried to pack up the desk, but I couldn’t pick up my pen to put it away in the drawer - I knocked it off the desk and then I couldn’t figure out how to get down there to pick it up.
My husband came and got me and led me to the car and as soon as it started moving, my headache intensifed and nausea overwhelmed me. By the time we arrived in the ER I must have looked pretty bad because they took me in without even having to sit down in the waiting room.
One neurologist appointment, CT and two different EEGs later, it was called a “classic migraine.” Never had another.
My paralysis dreams are like this. Oftentimes they conclude with a buzzing or ringing sound. Even though I know I’ve just had a paralysis dream, I’ll often need to check that nothing’s happened because it seems hard to accept that the noise was entirely imaginary.
I get those too! You’re the first person I’ve heard describe these…
Sometimes I get a whole cascade of these memories and it’s among the most pleasant feelings I can experience.
I wondered whether they might be fragments of dream memories.
Due to complex partial seizures of the left temporal lobe I get Auditory Hallucinations… I hear people say things they are not saying. At first I thought my friends were yanking my chain…we were at a backyard picnic, and there was drinking involved… It wasn’t until I heard the ESPN guy, who was describing the baseball playoffs, start talking about something else (I can’t remember what is said after a minute or so) that I knew it was real. I backed up the TIVO and he was talking baseball the whole time. Kinda weird.
Occular migraine too. for me it’s mostly peripheral vision loss, although I recall once that I lost the center…that sucks, especially when driving. In fact, I was inthe hospital getting a CAT scan for potential stroke when the Challenger blew up. Kind of a Kennedy assasination thing.
Just an update - nearly a month later and the SSRI discontinuation syndrome is still going. Much less frequently than it was when I posted back in May, but I’m still finding if I’m overly tired (or hungry) or feeling ill, the zaps tend to make a reappearance.
I’ve had brain zaps before but I can’t remember what drug caused them. Maybe Wellbutrin? I don’t know, but they are no fun at all.
I have a lot of quirky things that happen to me, but the strangest happened a couple of months ago. I was working at my computer and all a sudden I could hear this hissing noise. More like “SHHHHHHHHHH!” It increased in volume and pitch and was very annoying. I ran out of my office and poked my head into the nearest cubicle, where there were two people talking, and I asked them if they knew what that annoying sound was about. They looked at me like I was crazy. I asked another person. She looked at me like I was crazy. I sat back down at my desk and mullled over the sound, which gradually quieted. I realized that I had just experienced a brief spell of tinnitus. A side-effect of one of the drugs I was on. I can’t remember which one though.