Trauma, Head Injury, and FND: What Happens in the Brain and How You Can Recover

Falling and hitting your head can be a frightening experience. For some, the consequences extend beyond physical bruising or a concussion. In certain cases, individuals begin to experience unusual neurological symptoms that aren’t explained by structural damage on brain scans—such as weakness, tremors, or dissociative episodes. This can lead to a diagnosis of Functional Neurological Disorder (FND).

This article explores how FND can develop after a traumatic brain injury (TBI), what the symptoms look like, and how emerging treatments like Eye Movement Desensitisation and Reprocessing (EMDR) therapy may offer support.

What Is Functional Neurological Disorder?

Functional Neurological Disorder (FND), sometimes called conversion disorder, refers to a condition in which a person experiences neurological symptoms (such as seizures, movement difficulties, or sensory issues) that appear to be caused by a problem in the functioning of the nervous system, rather than a detectable structural abnormality. FND is a genuine medical condition with specific diagnostic criteria, and is not an entirely psychological disorder; it is recognised as a disorder of nervous system functioning with real, diagnosable features.

According to Stone et al. (2009), FND is one of the most common diagnoses in neurology clinics after conditions like epilepsy and migraine, yet it remains widely misunderstood. Many patients are affected by FND, but its exact prevalence is still uncertain. It is not “all in your head”—these are real, disabling symptoms that can be linked to past trauma, stress, or physical injury. Diagnosis relies on clinical neurology and the expertise of health professionals and medical professionals, using positive clinical signs and specific diagnostic criteria, rather than just psychological explanations. FND is part of a broader group of functional neurological disorders and functional disorders, and can be confused with related disorders or neurological disorders such as multiple sclerosis.

Common Symptoms of Functional Neurological Disorder After a Head Injury

After a traumatic brain injury—whether mild or severe—some people begin to develop functional symptoms. FND presents with specific clinical features and positive clinical features that help distinguish it from other conditions. These may include:

Muscle weakness or paralysis (often in a limb or one side of the body), including functional weakness and limb weakness
Non-epileptic seizures (also known as dissociative seizures)
Tremors, jerking movements, or gait problems, including functional tremor and other functional movement disorders
Functional dystonia, which may present as abnormal postures such as an inverted ankle or clenched fist
Speech difficulties or sudden mutism, including speech symptoms such as stuttering or whispering
Visual or sensory disturbances, including altered sensation and sensory symptoms like numbness or tingling
Dissociation or feeling detached from the body
Fatigue, cognitive fog, or difficulty concentrating, as well as cognitive symptoms such as memory or word-finding difficulties
Persistent postural perceptual dizziness, a recognised subtype of FND

Positive signs and diagnostic criteria are used to identify FND, including features such as functional weakness, limb weakness, and functional movement disorders. These physical symptoms and other FND symptoms can overlap with movement disorders and movement disorder presentations, but are identified by their functional nature.

These symptoms can emerge days, weeks, or even months after the initial injury.

Risk Factors: How Can a Head Injury Trigger FND?

While a traumatic brain injury can cause structural damage, many cases—particularly mild TBIs or concussions—do not leave lasting changes visible on scans. Brain imaging such as MRI or CT is often normal in cases of functional neurological disorder (FND), which distinguishes it from other neurological conditions that show structural abnormalities. However, the neurological functioning of the brain can still be affected. FND is a functional neurological disorder that impacts brain functions without structural damage, and it can occur alongside other neurological conditions.

The Role of the Brain’s Threat Detection System

After a head injury, the brain’s threat response system (involving the amygdala, brainstem, and autonomic nervous system) may remain overactive. This is part of a survival mechanism—your brain remains on high alert. In some people, especially those with a history of earlier trauma or nervous system sensitivity, this hyperactivation may contribute to dysfunctional brain-body signalling, which underpins FND.

Recent scientific findings support the role of psychological factors, psychological stress, and stressful life events as predisposing factors for FND. Many different predisposing factors and risk factors, including physical trauma and psychological stress, can influence symptom onset in FND.

A study by Aybek et al. (2014) using functional MRI found altered connectivity between emotion-processing areas of the brain (e.g. amygdala, anterior cingulate cortex) and motor control centres in individuals with FND, suggesting that emotional trauma and motor symptoms are neurologically linked.

Trauma, Memory, and Disrupted Processing

Injury-related trauma may also be “held” in the body in a way that prevents the brain from integrating the experience. This unresolved stress or trauma, including physical trauma, can show up later as neurological symptoms—especially in those with a history of adverse childhood experiences (ACEs), dissociation, or complex PTSD. Adverse childhood experience is a recognised risk factor for dissociative neurological symptom disorder and functional neurological symptom disorder.

Functional neurological disorder (FND) is classified as a neurological symptom disorder and is often associated with psychological disorders and psychological factors, as well as physical trauma.

What the Research Says About Treating FND

FND treatment is most effective when it includes psychoeducation, physiotherapy, physical therapy, and psychological support. A landmark 2020 randomised controlled trial by Nielsen et al. showed that specialised physiotherapy focused on retraining movement and attention to the body led to significant improvement in patients with functional motor symptoms. Physical therapy is a key component of treatment for functional motor disorders and functional movement disorder, helping to restore normal movement and reduce symptoms.

Key components of FND treatment often include:

Psychoeducation: Understanding the condition can be healing in itself.
Physiotherapy/Physical therapy: Focused on restoring normal movement patterns using graded exposure and redirection of attention, especially for functional motor disorders and functional movement disorder.
Psychological therapies: Psychological therapy, including cognitive behavioural therapy (CBT) and trauma-focused approaches, is important for addressing underlying psychological factors, dissociation, and body-mind integration.

Recent research continues to explore new therapeutic options for FND. Clinical trials are ongoing to evaluate innovative treatments, including transcranial magnetic stimulation, and early diagnosis is crucial for better outcomes.

CBT and FND: Common Practice, Mixed Results

In many NHS and neuropsychological services, Cognitive Behavioural Therapy (CBT) is the standard psychological intervention offered to people with FND. This approach is often aimed at helping individuals identify and reframe unhelpful thoughts and behaviours that may be reinforcing their symptoms.

FND is classified separately from other mental disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and is not considered an entirely psychological disorder. While FND was once thought to be an entirely psychological disorder, modern understanding recognises its multifactorial causes, including neurological and psychological factors. Psychological therapy, including trauma-focused and mind-body approaches, is often used alongside CBT, especially for those with co-occurring psychological disorders.

Potential Benefits of CBT for FND:

Structured support for managing stress, anxiety, or avoidance behaviours
Helpful in addressing secondary distress such as health anxiety or catastrophising
Can be delivered in a short timeframe, which fits well with service models
Some evidence suggests CBT may reduce seizure frequency in functional seizures (Goldstein et al., 2010)

Limitations of CBT for FND:

CBT focuses largely on conscious thoughts, which may miss non-verbal or body-based trauma—a key component in many FND presentations
Clients with histories of trauma, dissociation, or sensory dysregulation may find CBT too cognitive, overlooking the nervous system’s survival responses
Some people report feeling invalidated or “blamed” if CBT is not trauma-informed or delivered without a clear understanding of FND

For some clients, CBT can be helpful as part of a broader treatment plan—but for others, especially those with unresolved trauma or high levels of dissociation, other therapies may be more effective.

Can EMDR Help with FND After Head Injury?

Eye Movement Desensitisation and Reprocessing (EMDR) is a trauma therapy that helps the brain process and integrate overwhelming experiences. Originally developed for PTSD, EMDR is increasingly being explored as a treatment for FND—particularly when there is a clear traumatic trigger such as a fall, accident, or assault.

How EMDR May Help:

Accessing the root of symptoms
EMDR helps clients revisit the moment of injury or earlier trauma in a safe, structured way, reducing the emotional and somatic charge that keeps the nervous system stuck in “threat mode.”
Processing implicit memories
FND symptoms may be connected to non-verbal, body-based memories. EMDR allows access to these implicit experiences and integrates them into conscious awareness.
Calming the threat system
By desensitising the traumatic memory and reducing the brain’s alarm response, EMDR helps shift the system out of freeze, dissociation, or protective shutdown.

Case Study Support

A 2021 case series by Hull et al. found that EMDR therapy led to a reduction in seizure-like symptoms and improvements in emotional regulation for individuals with FND, even when symptoms were longstanding. While more large-scale trials are needed, early evidence is promising.

Integrative Support: A Holistic Approach

Healing from FND often requires addressing both the body and the mind. The most effective approaches tend to be multidisciplinary, combining:

Trauma-informed psychotherapy (e.g. EMDR or IFS)
Functional physiotherapy
Occupational therapy
Lifestyle support (e.g. pacing, sleep, nutrition)

Therapies that focus on body-mind integration—such as EMDR, Internal Family Systems (IFS), or sensorimotor psychotherapy—can be particularly helpful in reducing the internal disconnection often found in FND.

Final Thoughts

If you’ve developed neurological symptoms after a fall or head injury, you are not alone—and you are not imagining it. Functional Neurological Disorder is real, and recovery is possible. While symptoms can feel confusing or frightening, they are often reversible with the right support.

If trauma or dissociation may be part of your experience, therapies like EMDR offer hope for healing—not by forcing you to re-tell the story, but by gently helping your nervous system to release it.

Further Support

If you’re seeking therapy for FND or trauma following a head injury, I offer EMDR therapy, IFS, and body-focused trauma work online and in-person. Visit www.philipbrucetherapy.co.uk for more information or to book a consultation.