Most concussions resolve on their own. Rest, time, gradual return to activity. But some don't. And when they don't, the symptoms that persist often look a lot like dysautonomia.
When Vision Changes After Head Injury
One of the most common persistent symptoms after concussion is visual disruption — and it's not always an eye problem.
“One of the things we notice is that after head injury, we can see people that had normal vision all of a sudden feel like they need corrective lenses, or their vision might change. Or with autonomic problems, we get sick and all of a sudden our vision changes. And the question is — is there something that's wrong with our eyes, or is there something wrong with the processing or the control of how our eyes work together?”
The eyes might be fine. The problem is how the brain is controlling them. Eye movement control involves the same brainstem and cerebellar structures that regulate autonomic function. When those structures are disrupted by injury, you get both visual and autonomic symptoms.
The Blood Flow Problem
Persistent post-concussion symptoms often come down to cerebral blood flow. When the brain's regulation of blood flow is disrupted, it can't adequately fuel itself during demand.
“As soon as she went upright, the perfusion to her head was significantly lower than what we would want it to be. And notably for her, when we made her dual task — when we upped the ante a little and added a cognitive demand — instead of that blood flow pulling up like we'd want it to, it actually pulled down even further... tough way to live if you're a 17-year-old trying to go to school.”
Standing is hard. Standing and thinking is harder. The system can't manage both demands, so blood flow drops further. This is why post-concussion patients often can't tolerate school, work, or social settings — the cognitive demand on top of being upright overwhelms the system.
The Cerebellum Connection
The cerebellum plays a central role in both post-concussion recovery and autonomic regulation. When it's not working well, the downstream effects show up everywhere.
“A lot of times the coordination stuff when we see problems with that, that'll be our cerebellum. And it's interesting that we had those tests come up on the right side because the right cerebellum correlates with the function of the left brain. So when we see decrease in the perfusion to the left brain and also decrease to the coordination of the cerebellum on the right, we're starting to see sort of a tie-in between the two.”
The cerebellum isn't just about coordination. It fine-tunes cardiovascular reflexes. When it's compromised by injury, the reflexes that keep blood flowing to the brain during position changes lose their precision.
It's Not "Just Post-Concussion Syndrome"
Too often, persistent post-concussion symptoms get lumped into a vague diagnosis of "post-concussion syndrome" and managed with rest, medications, and time. But when specific systems aren't recovering — when blood flow regulation is impaired, when eye movement control is disrupted, when the cerebellum isn't calibrating properly — identifying and addressing those systems is what drives recovery.
“We were able to put her back up on that tilt table exam and see that the perfusion levels normalized while she was upright, which her and her mom were super pumped about.”
Measurable, objective improvement. Not just "feeling a little better." Normalized blood flow.
Key Takeaways
- Persistent post-concussion symptoms overlap heavily with dysautonomia
- Vision changes after head injury are often about brain processing, not the eyes themselves
- Cerebral blood flow regulation is frequently disrupted and drops further under cognitive demand
- The cerebellum coordinates both motor and autonomic reflexes — injury here affects both
- Specific testing can identify the mechanism and guide targeted recovery
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