Odd Symptom Decoding Filter: Kineto-Visual Edition
January 2, 2023 3:08 PM Subscribe
For several months, a friend in her early 50s has been experiencing some odd quasi-visual symptoms in very specific circumstances. Help us label and understand them.
The recurring symptom is a sort of visual confusion or disorientation which is neither dizziness nor blurriness. She once said that things looked “swimmy out there” while gesturing towards some point out ahead of us, but more often describes it as difficulty in judging distances, i.e. telling how far away things are. Things don’t look different, but they’re a little harder to make sense of spatially. Things that are far away are less affected, while nearer objects are more affected.
Triggering this experience seems to require both movement and some very modest amount of physical exertion. It happens quite consistently while bicycling, and occasionally while walking, but never while driving and never while exercising in place, e.g. weight training, dancing, etc. It’s exacerbated by the more irregular movements that go with cycling over mud or loose gravel, or walking down uneven slopes. It seems more likely when movement is sustained, such as a ride or walk on a long trail, and less likely when circumstances of the activity necessitate frequent pauses, such as riding or walking in the city where one must wait at intersections. The symptom dissipates within a couple of minutes if she stops moving. The symptoms can be quite unsettling, but don’t appear to be a serious threat to safety; she’s never stumbled or veered off a path because of them, though she has misjudged the proximity of a pothole or two.
She’s asked her eye doc, who couldn’t find anything wrong with her eyes or her prescription (multifocal contacts to correct nearsightedness). She has an upcoming appointment with a specialist in balance issues, but this doesn’t seem to be a balance issue and the preparatory questionnaire she was given seems mostly irrelevant. Does any of this sound familiar to you? If nothing else, it would really be nice to have clearer language to describe these symptoms, if only to help us identify appropriate professionals to talk to.
The recurring symptom is a sort of visual confusion or disorientation which is neither dizziness nor blurriness. She once said that things looked “swimmy out there” while gesturing towards some point out ahead of us, but more often describes it as difficulty in judging distances, i.e. telling how far away things are. Things don’t look different, but they’re a little harder to make sense of spatially. Things that are far away are less affected, while nearer objects are more affected.
Triggering this experience seems to require both movement and some very modest amount of physical exertion. It happens quite consistently while bicycling, and occasionally while walking, but never while driving and never while exercising in place, e.g. weight training, dancing, etc. It’s exacerbated by the more irregular movements that go with cycling over mud or loose gravel, or walking down uneven slopes. It seems more likely when movement is sustained, such as a ride or walk on a long trail, and less likely when circumstances of the activity necessitate frequent pauses, such as riding or walking in the city where one must wait at intersections. The symptom dissipates within a couple of minutes if she stops moving. The symptoms can be quite unsettling, but don’t appear to be a serious threat to safety; she’s never stumbled or veered off a path because of them, though she has misjudged the proximity of a pothole or two.
She’s asked her eye doc, who couldn’t find anything wrong with her eyes or her prescription (multifocal contacts to correct nearsightedness). She has an upcoming appointment with a specialist in balance issues, but this doesn’t seem to be a balance issue and the preparatory questionnaire she was given seems mostly irrelevant. Does any of this sound familiar to you? If nothing else, it would really be nice to have clearer language to describe these symptoms, if only to help us identify appropriate professionals to talk to.
Agree with the suggestion to see a neurologist! I had similar ongoing symptoms following a concussion in 2019, with a similar list of activities that would either be ok or triggering. I also had difficulty switching between near & distance vision but my regular optometrist didn’t think it was time for bifocals. My neurology NP sent me to a neuro-opthalmologist who diagnosed it as a convergence insufficiency and I did about a year of vision therapy. I still have days when my depth perception is a little off and I have to keep up with the exercises, but I’m back to trail running with confidence.
posted by kiripin at 3:57 PM on January 2, 2023 [1 favorite]
posted by kiripin at 3:57 PM on January 2, 2023 [1 favorite]
If one half of your field of view is affected in both eyes, it's probably happening in the brain (the visual signals cross over on the way from your eyes to your brain in a way that combines the signals from both eyes but separates the left and right halves of your field of view, sending each half to the opposite half of your brain).
posted by panic at 4:12 PM on January 2, 2023
posted by panic at 4:12 PM on January 2, 2023
If I were her, the first thing I would do when this happens is spin around on the spot three or four times fast while letting my head roll around. It sounds to me like this could be the visual anomalies that happen when someone is dizzy, and if she finds she can't make four spins without starting to stagger or risking falling down she will know it's that.
As to why she is getting dizzy, it could be that she's not getting enough blood supply to the brain at these times. If she feels weak at the knees or sleepy, when her vision goes this way those are also symptoms of dizziness. People don't always know when they are dizzy. She'll still need to do a follow up to figure out why she is getting badly dizzy at these times, but testing to see if it is dizziness is an easy diagnostic she can do herself and worth trying before she sees any professionals.
posted by Jane the Brown at 5:47 PM on January 2, 2023
As to why she is getting dizzy, it could be that she's not getting enough blood supply to the brain at these times. If she feels weak at the knees or sleepy, when her vision goes this way those are also symptoms of dizziness. People don't always know when they are dizzy. She'll still need to do a follow up to figure out why she is getting badly dizzy at these times, but testing to see if it is dizziness is an easy diagnostic she can do herself and worth trying before she sees any professionals.
posted by Jane the Brown at 5:47 PM on January 2, 2023
Probably not it, but have her check the graphic on the Wikipedia page for scintillating scotoma to see if she's experiencing the classic visual disturbance associated with some migraines.
posted by deludingmyself at 6:08 PM on January 2, 2023 [4 favorites]
posted by deludingmyself at 6:08 PM on January 2, 2023 [4 favorites]
Is it perhaps a vestibular problem? If she’s not staggering and falling, maybe not, but it sounds a little bit like the milder end of vertigo symptoms.
posted by Lawn Beaver at 6:56 PM on January 2, 2023 [1 favorite]
posted by Lawn Beaver at 6:56 PM on January 2, 2023 [1 favorite]
Our brains continuously construct a model of what objects exist and where they are with respect to us, and to our direction and speed of movement, through the 3D space around us. This involves integrating inputs from a whole pile of concurrent sensory systems. It's not all done in the visual processing subsystem - it needs help from our proprioception and balance sensors as well, if only to establish a meaning for the direction of the line along which our two eyes are separated.
There are a lot of ways in which this modelling can fail temporarily, and when it does we can feel unusual for a while. Vertigo and seasickness are the most notorious such failures because both are deeply unpleasant, but when modelling failures resolve more quickly or aren't so serious to begin with, sometimes they're just not noticeable enough to draw attention and we just plough on regardless.
What's happening with your friend strikes me as well within the range of what I occasionally experience during episodes of postural hypotension. If I get a sudden and strong drop in brain blood pressure then I'll see stars and feel in danger of falling over, but if I get a tiny mild one then all I notice is a very slight disorientation that mainly manifests as temporary depth perception anomalies.
It's possible to play with this kind of thing without even needing the hypotension: keep your gaze on something fairly distant while rapidly shaking and wobbling your head for a few seconds, then immediately look around and try to judge how far away something closer is. If I do this and pay very close attention, I can definitely feel the moment when my brain re-achieves its target lock on reality and everything makes sense again. Takes about a quarter of a second from when the wobbling stops. Without the wobbling beforehand it's way faster.
So that balance specialist consultation might be more use than either of you expects.
posted by flabdablet at 9:12 PM on January 2, 2023
There are a lot of ways in which this modelling can fail temporarily, and when it does we can feel unusual for a while. Vertigo and seasickness are the most notorious such failures because both are deeply unpleasant, but when modelling failures resolve more quickly or aren't so serious to begin with, sometimes they're just not noticeable enough to draw attention and we just plough on regardless.
What's happening with your friend strikes me as well within the range of what I occasionally experience during episodes of postural hypotension. If I get a sudden and strong drop in brain blood pressure then I'll see stars and feel in danger of falling over, but if I get a tiny mild one then all I notice is a very slight disorientation that mainly manifests as temporary depth perception anomalies.
It's possible to play with this kind of thing without even needing the hypotension: keep your gaze on something fairly distant while rapidly shaking and wobbling your head for a few seconds, then immediately look around and try to judge how far away something closer is. If I do this and pay very close attention, I can definitely feel the moment when my brain re-achieves its target lock on reality and everything makes sense again. Takes about a quarter of a second from when the wobbling stops. Without the wobbling beforehand it's way faster.
So that balance specialist consultation might be more use than either of you expects.
posted by flabdablet at 9:12 PM on January 2, 2023
It's possible that she's experiencing issues with her vestibular system, which is responsible for balance and coordination of eye movements with head movements so that we can keep our eyes steady when moving.
This article is quite helpful
posted by Zumbador at 11:04 PM on January 2, 2023 [1 favorite]
This article is quite helpful
posted by Zumbador at 11:04 PM on January 2, 2023 [1 favorite]
I'll add that scotoma is not always obvious. Last time I had it it started as 'reading is hard' and if it had stayed at that level and not gone all sparkly I would have put it down to tired eyes. It has only happened to me rarely and I don't get the subsequent migraine that would be a big clue what was going on, but effectively it starts as a bit of a blind spot the brain tries to talk you out of, and I can see how 'swimmy' might be a good description of that.
posted by How much is that froggie in the window at 11:21 PM on January 2, 2023
posted by How much is that froggie in the window at 11:21 PM on January 2, 2023
A neurologist is a good idea. But if they also can't find anything wrong, this is the track I would suggest pursuing: her doctor is probably an opthalmologist. I would recommend that she consults a behavioral optometrist. They consider vision problems holistically and they think about how vision is connected to hearing, locomotion, etc.
I had very unpleasant eye/vision issues some years ago that turned out to be a result of TMJ -- conventional eye doctors and also neurologists couldn't find anything wrong with me, said my prescription was appropriate, tried to convince me that I was having migraines (I was not).
A behavioral optometrist performed tests with me I didn't know existed, that seemed so peculiar -- he literally watched me read. He blindfolded me and had me touch a ringing bell with different prisms over my (closed) eyes -- with some prisms I could hit the bell with my finger with great ease, with other prisms (again, my eyes were closed) I could not locate it in space.
My issue turned out to be more complex than just the eye symptoms, but he figured out what was going on with the eye component, and how to address it appropriately.
posted by virve at 5:57 PM on January 3, 2023
I had very unpleasant eye/vision issues some years ago that turned out to be a result of TMJ -- conventional eye doctors and also neurologists couldn't find anything wrong with me, said my prescription was appropriate, tried to convince me that I was having migraines (I was not).
A behavioral optometrist performed tests with me I didn't know existed, that seemed so peculiar -- he literally watched me read. He blindfolded me and had me touch a ringing bell with different prisms over my (closed) eyes -- with some prisms I could hit the bell with my finger with great ease, with other prisms (again, my eyes were closed) I could not locate it in space.
My issue turned out to be more complex than just the eye symptoms, but he figured out what was going on with the eye component, and how to address it appropriately.
posted by virve at 5:57 PM on January 3, 2023
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I am a neuro NP and someone like this that I saw, I would at least talk to our neuro-ophtho team or neuro-otology...one guy...to make a better determination to refer up, but I work in a very comprehensive center.
posted by cobaltnine at 3:18 PM on January 2, 2023 [2 favorites]