Thread by @ZdenekVrozina

A major new review from Yale (Moen, Baker, Iwasaki, 2025) offers the most comprehensive picture yet of what SARS-CoV-2 does to the nervous system.
The conclusion is stark:
Long COVID is a chronic neuroimmune disorder affecting brain, spinal cord, and peripheral nerves.🧵

Warning Sign #1: The pandemic didn’t end - it just changed shape.
The virus keeps evolving. The acute symptoms may fade.
But for many, the infection never truly ends.
Even young, previously healthy people experience:
mental fog,
dizziness when standing,
sensory disturbances,
exhaustion after minimal effort,
racing heart.
That’s Long COVID.

Warning Sign #2: The virus leaves behind molecular debris - and the immune system won’t let it go.
Sometimes it’s spike protein fragments in the blood.
Sometimes viral RNA in the olfactory bulb or even the skull.
This triggers persistent immune alarms:
T cells get activated
Inflammation spreads to the brain
Neuronal connections start breaking down
The war continues - long after the virus is gone.

Warning Sign #3: The brain gets sick - even when standard scans look “normal.”
MRI often misses it. But PET imaging shows:
reduced glucose metabolism in the brainstem,
limbic inflammation,
microglia digesting synapses.
Patients say:
“I know what I want to say, but I can’t get it out.”
It’s inflammatory disruption of higher brain function.

Warning Sign #4: It’s not just the brain - the body’s autopilot system begins to fail.
The autonomic nervous system - which controls heart rate, blood pressure, digestion - goes haywire.
Blood pools in the legs; the brain is starved of oxygen.
POTS, dizziness, blackouts, heat intolerance
Even the vagus nerve - the main communication line between brain and body - shows structural damage in some studies.

Warning Sign #5: The immune system may start attacking the nervous system itself.
After infection, some people develop autoantibodies:
against adrenergic receptors,
against cholinergic synapses,
against neurons.
In experiments, these antibodies from Long COVID patients were transferred to mice - and caused neurological symptoms.
This isn’t just immune activation. It’s autoimmunity.

Warning Sign #6: Smell loss isn’t just a quirky symptom - it’s a red flag.
Olfactory tissue often shows:
inflammation,
neuronal destruction,
lingering T cells months after infection.
Even after viral clearance, the damage and local immune activity can persist - blocking recovery.
Smell loss may signal long-term damage to the central nervous system.

Warning Sign #7: Spike protein isn't just debris - it can fuel clotting and inflammation.
Persistent spike fragments have been found in blood and even skull tissue months post-infection.
They bind fibrin - form resistant microclots
These can obstruct capillaries, disrupt brain perfusion, and trigger microglial activation, cause ischemia-reperfusion injury
Even without active virus, brain tissue can be damaged by the aftermath of infection.

Warning Sign #8: SARS-CoV-2 may accelerate brain aging.
Evidence from autopsies, mice, and imaging shows:
damage to dopamine neurons,
loss of neurogenesis in the hippocampus,
inflammatory profiles resembling Parkinson’s and Alzheimer’s.
For some, COVID acts as an accelerant for neurodegenerative processes.

Warning Sign #9: No one is exempt. Not the young. Not the recovered.
Reinfections raise the risk.
Immunological imprinting may alter long-term responses.
Long COVID is not rare - it’s the aftermath of a system-wide disruption.
With no diagnostic test.
No cure.
And millions affected globally.

Bottom line: Long COVID isn’t “just fatigue.”
It’s:
chronic neuroinflammation,
immune dysregulation,
vascular dysfunction,
autonomic breakdown.
It’s a warning that infectious disease can leave lasting biological scars - not just in “high-risk” groups, but in anyone. @szupraha @ZdravkoOnline

Moen et al. (2025) - Neuroimmune Pathophysiology of Long COVID onlinelibrary.wiley.com/doi/10.1111/pc…