09 / Post-concussion & TBI

Why Do I Feel Dizzy, Nauseous or Anxious After a Concussion? Brainstem Traction & Autonomic Balance

Cranial Solutions15 May 20256 min read

Dizziness, nausea, motion sensitivity and sudden spikes of anxiety after a concussion are associated with mechanical strain at the craniocervical junction (where the skull meets the neck) and changes in autonomic balance. The brainstem and vagus nerve (CN X) pass through the narrow gateway at the base of the skull. When a concussion affects upper neck joint alignment (C1/C2) and tightens the myodural bridge, it may place traction on brainstem nerve centres. This strain is associated with a shift towards "fight-or-flight" activity, vagal nausea and neck-related dizziness.

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The Biomechanical Problem: Traction at the Brainstem Gateway

The craniocervical junction is one of the most nerve-dense areas of the body. Passing through the foramen magnum and upper neck canal are vital nerve pathways, including the lower brainstem, the vagus nerve (CN X), the vestibular (balance) nuclei and the sympathetic nerve chain.

From Neck Strain to Three Symptom Pathways

Step 1: C1/C2 alignment changes and myodural bridge tension.
Step 2: Mechanical traction at the brainstem and craniocervical gateway.
Pathway A - Vagus nerve (CN X): associated with nausea and queasiness.
Pathway B - Vestibular nuclei: associated with neck-related dizziness.
Pathway C - Sympathetic chain: associated with fight-or-flight anxiety.

During a concussion or whiplash injury:

Upper neck alignment: the atlas (C1) and axis (C2) vertebrae may become restricted in an asymmetrical position.
Myodural traction: tightening of the suboccipital muscles may carry ongoing pull through the myodural bridge into the dura around the brainstem.
Autonomic imbalance: strain on brainstem centres may alter autonomic signalling, shifting the body away from its calm "rest-and-digest" state towards ongoing fight-or-flight activity.

See how neck and cranial drivers are assessed on our Post-Concussion Symptoms & TBI page.

Comparison: Inner Ear Dizziness vs. Craniocervical Strain

Primary site

Inner ear vestibular dysfunction: Semicircular canals in the inner ear.
Craniocervical strain model: Upper neck (C1/C2) and brainstem junction.

Dizziness quality

Inner ear vestibular dysfunction: Spinning vertigo (room spinning).
Craniocervical strain model: Unsteady, "floating" or off-balance feeling.

Associated nausea

Inner ear vestibular dysfunction: Triggered mainly by rapid head movement.
Craniocervical strain model: Ongoing queasiness and slowed digestion.

Autonomic impact

Inner ear vestibular dysfunction: Little effect on heart rate variability.
Craniocervical strain model: Associated with sudden anxiety, racing heart and fatigue.

Structural driver

Inner ear vestibular dysfunction: Dislodged ear crystals (BPPV).
Craniocervical strain model: Upper neck alignment and myodural dural tension.

Clinical feature	Inner ear vestibular dysfunction	Craniocervical strain model
Primary site	Semicircular canals in the inner ear.	Upper neck (C1/C2) and brainstem junction.
Dizziness quality	Spinning vertigo (room spinning).	Unsteady, "floating" or off-balance feeling.
Associated nausea	Triggered mainly by rapid head movement.	Ongoing queasiness and slowed digestion.
Autonomic impact	Little effect on heart rate variability.	Associated with sudden anxiety, racing heart and fatigue.
Structural driver	Dislodged ear crystals (BPPV).	Upper neck alignment and myodural dural tension.

How Brainstem Strain Is Associated With Symptoms

Strain at the base of the skull may affect three major nerve pathways:

Vagus Nerve (CN X) Irritation

The vagus nerve supplies calming parasympathetic signals to the stomach and heart. Traction near the jugular foramen and upper neck may irritate vagal fibres, associated with nausea, slowed digestion and motion intolerance.

Neck-Related (Cervicogenic) Dizziness

The suboccipital muscles are packed with position sensors. When myodural strain distorts these signals, the brain may receive conflicting information about head position, associated with dizziness and visual disorientation.

Sudden Anxiety Spikes

Brainstem strain may reduce calming vagal tone, letting the sympathetic system dominate. This is associated with sudden adrenaline surges, a racing heart and anxiety without an obvious trigger.

Feeling dizzy, queasy or on edge since a head knock? Read more on our Post-Concussion Symptoms & TBI page.

Supporting Movement and Autonomic Balance

Supporting autonomic balance involves easing mechanical strain at the brainstem gateway:

Upper neck care: addressing atlas (C1) and axis (C2) alignment aims to reduce mechanical strain on the upper spinal canal.
Endonasal inflation (Nasal RX): controlled, brief inflations within key inner nasal passageways aim to ease sphenoid and cranial dural strain, reducing tension on the dural sleeve around the brainstem.
Supporting autonomic tone: easing nerve traction aims to support normal vagal activity, which may help with nausea, heart rate steadiness and dizziness. Individual results vary.

Frequently Asked Questions

Why might I feel constant nausea and motion sickness after my concussion?

The vagus nerve (CN X), which helps regulate digestion and stomach settling, passes through a narrow opening at the base of the skull. Upper neck and dural strain may irritate vagal fibres, which is associated with nausea and motion sensitivity. Learn more on our Post-Concussion Symptoms & TBI page.

What is cervicogenic dizziness and how is it different from inner ear vertigo?

Inner ear vertigo usually causes a spinning sensation. Cervicogenic dizziness feels more like being off-balance, floating or on a moving boat, and is associated with strained neck position sensors at C1/C2 sending confusing signals to the brainstem. Read Why Am I Still Having Concussion Symptoms Months Later?

Can upper neck strain be linked to sudden anxiety after a head injury?

Strain on the upper neck and brainstem may reduce calming vagal activity, letting the fight-or-flight system become more active. This is associated with physical anxiety symptoms such as a racing heart and feeling on edge. Read Why Does the Base of My Skull Always Feel Tight?

For the full overview, visit our Post-Concussion Symptoms & TBI page.

Read Why Am I Still Having Concussion Symptoms Months Later?

Also see Why Does the Base of My Skull Always Feel Tight?

Neck strain also features in Migraines & Headaches.

Learn about our clinical approach.

Browse the published studies on our Research page.

References

01Dura Mater & Migraines Synthesis Report (2025). Biomechanical stiffness (28-86 MPa) and dural mechanics.
02StatPearls: Post-Concussive Syndrome (2024). Pathophysiology, vagal nerve tracts, and autonomic dysregulation. NCBI Bookshelf / NIH.
03Al-Khazali et al. (2022). Neck pain co-occurrence in concussion and migraine: a systematic review. Cephalalgia, 42(9): 910-921.
04Zheng N, Chung BS, Li YL, et al. (2023). The relationship between myodural bridge, suboccipital musculature, and cerebrospinal fluid dynamics. Scientific Reports, 13: 18882.

Learn how our non-surgical endonasal protocol is used to evaluate suitability for conservative management, and how cranial base structural mechanics guide an individual care plan.