02/02/2026
🧠 The Hidden Brain Circuits Behind Post-Concussion Syndrome —
New Research Explains What We See Every Day at The Functional Neurology Center
Post-concussion symptoms can linger, evolve, or suddenly flare months — even years — after the initial injury. Many patients who come to The Functional Neurology Center (FNC) say the same thing:
“I look normal, the scans are normal…
but I don’t feel normal.”
A major 2023 Frontiers in Neurology review helps explain exactly why this happens and supports what we evaluate and rehabilitate every day:
➡️ Concussions disrupt specific brain circuits and networks — NOT just isolated symptoms.
➡️ Different regions of the brain produce different symptom patterns.
➡️ Persistent symptoms reflect incomplete reintegration of neural networks.
This article breaks down the science and shows how it matches the comprehensive, multi-system approach we use at theFNC.
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🔍 THE RESEARCH: POST-CONCUSSION SYMPTOMS FOLLOW A BRAIN-REGION MAP
The review systematically connects neuroanatomy with the hallmark symptoms of post-concussion syndrome.
It identifies disruptions across six major neural systems:
1. Cortical motor & sensory regions
2. Subcortical limbic & cognitive centers
3. Visual & vestibular circuitry
4. Cerebellar networks
5. White matter communication pathways
6. Autonomic / brainstem regulation loops
When one (or several) of these circuits are impacted, predictable patterns of dysfunction emerge.
The more circuits involved, the more complex the presentation.
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1️⃣ CORTICAL NETWORKS — WHY BALANCE, COORDINATION & “BODY AWARENESS” CHANGE
The cerebral cortex controls movement, sensation, planning, attention, and sensory integration.
Concussion stressors include:
• Rotational acceleration
• Axonal stretching
• Cortical shearing
• Diffuse microinflammation
When affected, patients often develop:
✔ Altered somatosensory processing
Feeling “off,” disconnected, or lacking awareness of where the body is in space.
✔ Balance and gait instability
Cortical-motor disruption alters descending motor planning AND integration with cerebellar loops.
✔ Impaired dual-tasking
Walking while thinking, turning while talking, or navigating visually complex spaces becomes overwhelming.
✔ Motor sequencing issues
Difficulty performing coordinated movements, sport-specific tasks, or activities requiring timing.
This cortical disruption sets the stage for the “multi-layered” dysfunction that follows.
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2️⃣ LIMBIC & SUBCORTICAL SYSTEMS — WHY MOOD, MEMORY & EMOTIONS SHIFT
The review highlights the hippocampus, amygdala, thalamus, and basal forebrain — regions deeply involved in:
• Emotion regulation
• Stress response
• Sleep cycles
• Memory encoding
• Motivation
• Attention control
Concussion can destabilize these networks, producing:
✔ Emotional volatility
Irritability, sadness, fear, or “I cry for no reason.”
✔ Anxiety & hypervigilance
Limbic circuits misinterpret sensory overload as threat.
✔ Brain fog
Thalamic relay inefficiency and hippocampal stress slow normal thinking.
✔ Poor memory & recall
Especially under cognitive load or stress.
✔ Sleep disruption
Dysregulated circadian control impacts healing and autonomics.
This is neurological — not psychological.
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3️⃣ VISUAL + VESTIBULAR SYSTEMS — WHY THE WORLD FEELS “UNSTABLE”
The visual and vestibular systems share direct, high-speed pathways with one another and with the cerebellum and cervical spine.
Even mild dysfunction here creates dramatic symptoms:
✔ Light and motion sensitivity
Screens, stores, driving, scrolling.
✔ Visual motion overwhelm
The brain struggles to filter moving information (optic flow).
✔ Difficulty focusing, reading, or tracking
Saccadic and pursuit deficits create blurred or unstable vision.
✔ Dizziness & imbalance
If eye–ear–neck signals don’t match, the brain loses its stability map.
✔ Feeling detached or “floating”
A mismatch between vestibular input and visual grounding.
Concussions often create sensory mismatch, where eyes, inner ears, and neck proprioceptors are no longer synchronized.
This is a hallmark finding at theFNC.
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4️⃣ CEREBELLAR NETWORKS — THE “CONDUCTOR” OF MOTOR & COGNITIVE FUNCTION
The cerebellum coordinates:
• Balance
• Eye movements
• Proprioception
• Gait
• Reflexes
• Timing and rhythm
• Error correction
• Cognitive processing
Damage or inhibition here leads to:
✔ Instability in complex or busy environments
(Malls, airports, stores)
✔ Difficulty with head turns or rapid direction changes
✔ Fatigue during standing or walking
The brain must work harder to stabilize the body.
✔ Visual blurring with movement (oscillopsia)
✔ Slowed thinking, multitasking difficulty
The cerebellum helps coordinate not only movement — but thought.
Cerebellar dysfunction is one of the top contributors to chronic post-concussion symptoms.
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5️⃣ WHITE MATTER & NETWORK CONNECTIVITY — THE “WIRING” THAT MAKES EVERYTHING WORK
White matter tracts connect all brain regions.
They ensure efficient communication.
Concussions can cause:
• Axonal stretching
• Slowed conduction speed
• Microstructural disruption
• Neuroinflammatory changes
This produces:
✔ Slowed processing speed
✔ Cognitive burnout
✔ Difficulty keeping up in conversation
✔ Mental fatigue after small tasks
✔ Difficulty switching tasks
✔ Sensory overload when multitasking
✔ Crashing after a day of stimulation
This is why so many patients say:
“I can do the thing — but I can’t do the thing AND think.”
That is classic white-matter load intolerance.
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6️⃣ BRAINSTEM + AUTONOMIC CIRCUITS — THE HIDDEN DRIVER OF MANY PERSISTENT SYMPTOMS
The brainstem houses:
• Cranial nerve nuclei
• Vestibular nuclei
• Autonomic control centers
• Gaze stabilization pathways
• Postural reflex loops
Injury here contributes to:
✔ Heart rate variability issues
✔ Blood pressure swings
✔ Temperature dysregulation
✔ GI sensitivity
✔ Panic-like episodes
✔ Chronic fatigue
✔ Difficulty tolerating exertion
Many PCS patients have under-recognized cervical-vestibular-autonomic integration issues — a signature focus at theFNC.
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**⚠️ WHY SYMPTOMS PERSIST:
MULTIPLE NETWORKS FAIL TO “REINTEGRATE”**
This review’s most important conclusion:
Concussions disrupt complex networks — not just one structure.
Healing requires reintegrating those networks, not simply waiting for symptoms to fade.
This explains why:
• Time alone does not heal everyone
• Symptoms can flare without re-injury
• Patients improve when circuits are targeted
• Many feel “stuck between systems”
• Rest, medication, and “standard PT” often aren’t enough
Persistent symptoms = persistent network dysfunction.
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🏥 HOW THE FUNCTIONAL NEUROLOGY CENTER REBUILDS THESE NETWORKS
We identify exactly which circuits were affected — then rehabilitate those circuits in a precise, layered, and progressively integrated way.
Our exam includes:
🔹 Neuro-visual & oculomotor testing
Saccades, pursuits, VOR, convergence, OKN, fixation stability.
🔹 Vestibular & otolith evaluation
Utricle, saccule, VOR pathways, gravitational orientation, head motion tolerance.
🔹 Cervical proprioceptive & stability assessment
Suboccipitals, JPE testing, neck–eye coordination, cervical reflexes.
🔹 Cerebellar activation & midline testing
Gait, posture, rhythm, timing, coordination.
🔹 Autonomic load testing
HRV, dysautonomia patterns, exertional tolerance.
🔹 White matter + network integrity screening
Processing speed, dual-tasking, divided attention, sensory load mapping.
This map becomes the blueprint for individualized care.
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🛠 OUR REHABILITATION MODEL: CIRCUIT-BASED NEURO-REINTEGRATION
We combine:
✔ Visual-Vestibular Integration
Optokinetics, gaze stabilization, head–eye–body retraining.
✔ Cervical Spine Neuromodulation
Joint receptor activation, proprioceptive reorientation, trigeminal (Vagus 2.0) stimulation.
✔ Cerebellar Activation
Balance training, rhythm timing tasks, ocular-cerebellar recalibration.
✔ Sensorimotor Integration
Dynamic surfaces, head motion challenges, multi-sensory loading.
✔ Cognitive & autonomic rehabilitation
Dual-task circuits, pacing strategies, graded exposure to stimulation.
✔ ARPwave Neuromodulation
Activation of cranial and spinal pathways, proprioceptive uptraining, limbic-vestibular modulation.
✔ Customized home programs
Reinforcing neural pathways daily for long-term reintegration.
Every therapy session is targeted.
Every drill has intention.
Every circuit is chosen based on your exam.
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🌟 WHAT WE WANT EVERY PATIENT TO KNOW
Your symptoms make sense.
They match specific brain regions and circuits identified in the research.
You are not broken.
You are not “making it up.”
You are not out of options.
And you are absolutely not alone.
**Your brain can be rehabilitated.
Your networks can reorganize.
Your function can return.
There is HOPE.**
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📩 READY TO START YOUR RECOVERY?
Our team specializes in helping complex concussion cases finally understand why they feel the way they do — and how to get better.
📧 info@theFNC.com
📞 612-223-8590
🌐 theFNC.com
https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1136367/full
