When most people think about brain injury, they picture something structural, a visible area of damage that shows up clearly on an MRI or CT scan. But there’s another layer to brain injury that’s much harder to see, and it may play a bigger role in ongoing symptoms than many patients realize. It’s called neuroinflammation, and understanding it can change the way you think about your own recovery.
Beyond What a Scan Can Show You
Standard brain imaging, like an MRI or CT scan, is excellent at showing structure. It can reveal where a stroke or injury occurred, how large the affected area is, and whether there’s visible tissue damage. What these scans can’t show is what’s happening at the chemical level inside the brain.
This is an important distinction, because a lot can be going on inside the brain that never shows up on a standard scan. One of the most significant of these hidden processes is neuroinflammation.
What Neuroinflammation Actually Is
Neuroinflammation is your brain’s immune system response after an injury. When your brain is injured, whether from a stroke, traumatic brain injury, or another cause, immune cells activate to help manage the damage. In the short term, this is a normal and even helpful process. It’s part of how your body responds to injury and begins repairing tissue and fighting off potential infection.
The problem arises when this inflammatory response doesn’t switch off the way it’s supposed to. When inflammation sticks around for a long time, rather than settling down once its initial job is done, it can start working against the very brain cells it was meant to protect.
The Role of TNF
Part of this inflammatory response involves a molecule called tumor necrosis factor, or TNF. In normal, everyday functioning, TNF plays a useful role in your body. But after a brain injury, TNF levels can rise well beyond what’s needed, and in some patients, they stay elevated.
When this happens alongside ongoing activation of the brain’s immune cells (called microglia), it’s referred to as persistent neuroinflammation. Research shows this state can last for years, quietly disrupting normal brain function long after the original injury took place.
How This Shows Up for Patients
When neuroinflammation and elevated TNF persist, they can interfere with how brain cells communicate with each other. Since so much of what your brain does relies on cells passing signals back and forth efficiently, this disruption can lead to a wide range of symptoms, and not always ones that seem obviously connected to the brain at first glance.
Common symptoms linked to neuroinflammation include fatigue, brain fog, mood changes, pain, and balance difficulties. Because these symptoms can show up gradually, sometimes months or even years after the original injury, they’re often mistaken for unrelated issues or simply written off as something patients have to live with.
Why These Symptoms Can Be So Hard to Treat
Here’s where things get particularly frustrating for a lot of patients: your brain is protected by something called the blood-brain barrier, a natural filtering system that controls what can and can’t pass from your bloodstream into your brain. This barrier is important for protecting your brain from harmful substances, but it also makes it difficult for many medications to reach the brain in meaningful amounts.
This means that even if elevated TNF and ongoing inflammation are part of what’s driving your symptoms, many standard medications simply aren’t able to reach the brain well enough to address the problem directly. As a result, these underlying chemical changes can persist for years, largely unaddressed, even while a patient continues to experience real, ongoing symptoms.
This helps explain why some stroke and brain injury survivors continue to struggle with fatigue, brain fog, or pain long after their initial recovery period, even when their scans look stable and unchanged.
A Treatment Designed to Reach the Brain
This is where perispinal etanercept (PSE) comes in. Etanercept is a medication designed to target and reduce excess TNF. The challenge, as mentioned above, has always been getting medication like this past the blood-brain barrier in a way that actually reaches the brain.
PSE addresses this through its method of delivery. Rather than relying on the medication to circulate through the bloodstream and hope it crosses the blood-brain barrier, PSE is introduced through a specialized injection technique designed to help the medication reach the brain more directly, specifically targeting the areas where elevated TNF may be driving ongoing symptoms.
Why This Matters for Your Recovery
If you’ve been living with symptoms like fatigue, brain fog, mood changes, or pain that haven’t improved, even years after your stroke or brain injury, it can be easy to assume these symptoms are simply permanent, or that there’s nothing more that can be done. But persistent neuroinflammation offers a different explanation, and importantly, one that may be addressable.
Understanding that these symptoms may be connected to an active, ongoing chemical process, rather than a fixed, unchangeable part of your recovery, opens up a different way of thinking about what’s still possible. Instead of viewing certain symptoms as something to simply manage or accept, it may be worth asking whether an underlying inflammatory process is still playing a role.
The Bottom Line
Neuroinflammation is a hidden but potentially significant factor in recovery after brain injury, one that doesn’t show up on standard imaging but can still meaningfully affect how you feel and function. Elevated TNF and persistent immune activity in the brain can disrupt communication between brain cells for years, contributing to symptoms like fatigue, brain fog, pain, and mood changes long after the original injury occurred.
Because the blood-brain barrier makes it difficult for many treatments to reach the source of the problem, these symptoms can go unaddressed for far longer than they need to. Understanding neuroinflammation is the first step toward exploring whether treatments designed to directly target it, like PSE, might be part of your path forward.
Learn How We Approach Neuroinflammation
