Neuro-inflammation and Neurological Disorders

Insights from Functional Medicine for a Resilient Brain and Nervous System

There are more than 600 known brain and nervous system disorders—from Alzheimer’s and Parkinson’s to multiple sclerosis and neuropathic pain. What many of these conditions share is a single underlying factor: neuro-inflammation—low-grade inflammation in the central nervous system (the brain and spinal cord).

Not only the brain and spinal cord, but also the peripheral nervous system—the network of nerves throughout the body—can be affected by immune activity. Often described as peripheral neuropathies or neuro-immunological reactions, these processes are increasingly recognized as part of a bigger picture: low-grade inflammation, both in the CNS and PNS, plays a central role in the development of symptoms and disease.

What Is Low-Grade Inflammation?

An acute inflammatory reaction is usually easy to recognize. Think of a splinter in your finger: the skin becomes red, warm, and painful. These are signs your immune system is working to protect and repair.

In the nervous system, this process is far more subtle. A severe infection, concussion, whiplash, or spinal cord injury can trigger low-grade inflammation. You won’t see it on the outside, but you may feel it inside—fatigue, memory or concentration problems, and mood changes when the brain is involved, or pain, tingling, and muscle weakness when the nerves are affected.

When Neuro-inflammation Becomes Chronic

An acute immune response is meant to be short and protective. But if immune activation becomes chronic—for example, when low-grade inflammation lingers for months or years—the immune system may begin to attack healthy cells. Neuro-inflammation then shifts from a healing mechanism to a source of damage.

As the blood-brain barrier weakens, unwanted substances slip through, fueling a vicious cycle of inflammation. Over time, this process has been linked to Alzheimer’s, Parkinson’s, multiple sclerosis, as well as depression and chronic pain syndromes. Within Functional Medicine, we see this as a crucial turning point: the moment when prevention and early intervention matter most.

Glial Cells: The Immune Guardians of the Brain

While neurons carry signals, about 70% of the central nervous system consists of glial cells, which are vital for immune balance:

• Microglia act as sentinels, detecting and clearing threats.
• Astrocytes regulate blood flow and maintain chemical balance.

When these cells remain active too long, the brain becomes exhausted. This is why chronic low-grade inflammation often lays the groundwork for later neurological problems—and why restoring balance is a central aim in Functional Medicine.

Neuroinflammation, Aging, and “Inflammaging”

This constant state of immune alarm can occur at any age but becomes especially important as we grow older. Researchers even speak of “inflammaging”: the process by which low-grade inflammation accelerates aging in the brain and nervous system.

This helps explain why memory loss, dementia, chronic pain, and other neurodegenerative conditions so often overlap with signs of inflammation. Functional Medicine approaches this not as a fixed outcome, but as a process that can be influenced—through nutrition, lifestyle and epigenetic interventions.

Scientific Insights Into Neuroinflammation

Recent research has highlighted the role of quinolinic acid (QUIN) in the kynurenine pathway. QUIN is not only a biomarker of low-grade inflammation but also a potential therapeutic target:

• Microglial activation and tryptophan diversion
In mouse models, increased KMO enzyme activity raises QUIN levels. Regulation via miR-132 reduces this production without suppressing overall microglial activity.

• FIRES and acute encephalopathies
In children with FIRES and other infection-related brain injuries, a combined CSF panel of neopterin and QUIN accurately signaled inflammation and neurotoxicity, outperforming standard CSF markers.

• MS and axonal loss
In patients with relapsing-remitting MS (RRMS), an elevated QUIN:KYNA plasma ratio was linked to axonal loss, measured via

• MRI and OCT.
Mitochondrial dysfunction and inflammation
Reviews show how disruption of the kynurenine pathway and mitochondrial imbalance reinforce each other, leading to both QUIN accumulation and mitochondrial damage.

• Chronic pain and depression
Elevated QUIN levels are also found in chronic pain and depressive disorders, highlighting its role in excitotoxicity and oxidative stress as a bridge between inflammation and mental health.

Functional Medicine Diagnostics

Conventional neurology investigates neuro-inflammation with MRI, lumbar puncture, or nerve conduction studies (EMG). In Functional Medicine, we go further. We don’t only ask where is the damage visible?—we also ask what underlying processes are fueling inflammation?

We use:
• Advanced laboratory testing
Beyond standard markers such as CRP and ESR, we measure cytokines (IL-6, TNF-α), markers of oxidative stress, mitochondrial function, and immune activation profiles. Quinolinic acid is increasingly used as a marker of neurotoxic immune activity.

• Gut microbiome and permeability testing
The gut-brain axis is essential for neurological health. Imbalances in gut flora or increased intestinal permeability (“leaky gut”) can feed systemic low-grade inflammation and worsen neuro-inflammation. Specialized testing maps microbiome composition, diversity, function, and gut barrier integrity.

• Nutrient and hormone profiles
Nutrients and hormones directly influence immune balance in the nervous system. Deficiencies in antioxidants, omega-3s, or B vitamins can amplify inflammation. Hormones such as cortisol, estrogen, and progesterone also modulate immune activity. Comprehensive testing reveals which factors worsen or calm neuroinflammation.

By integrating these data layers, we create a systems overview of how the immune system, metabolism, hormones, and gut health interact. This makes it possible to design a personalized Functional Medicine care plan that not only relieves symptoms but also addresses the deeper drivers of neuroinflammation.

What This Means for You

Neuroinflammation is complex, but it is also modifiable. Within Functional Medicine, we always look at the bigger picture: nutrition, lifestyle, gut health, stress, sleep, and movement—all of which shape low-grade inflammation.

By identifying and improving these factors step by step, we can strengthen resilience and reduce the risk that neuroinflammation becomes chronic or develops into serious neurological conditions.

“Your nervous system is not an isolated system; it is a dynamic field where immune reactions, hormones, and thoughts continuously meet. By restoring balance, the brain can return to its original strength.”

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