Understanding Functional Neurological Disorder (FND): Symptoms, Movement, Attention, and Treatment

Functional Neurological Disorder, or FND, can affect movement, sensation, seizures, speech, cognition, and other neurological functions. Someone may experience weakness, tremor, difficulty walking, sensory changes, functional seizures, or problems with speech. The symptoms are real and involuntary.

One important change in how FND is understood is that it is no longer considered simply a diagnosis made after other conditions have been ruled out. Neurologists can diagnose FND by identifying positive clinical signs that are characteristic of functional neurological symptoms. Research into FND has grown considerably, but there is still no single explanation that accounts for every symptom or every person who develops the condition.

What Happens in FND?

FND involves altered neurological functioning. The symptoms are not intentionally produced. For example, someone with functional weakness may show preserved movement under certain conditions even though voluntary movement is difficult at other times. A functional tremor may change with distraction or when the person performs another movement. Functional seizures can resemble epileptic seizures but occur through a different mechanism.

These kinds of findings can provide positive clinical signs that support the diagnosis.

Research has also identified group-level differences in networks involved in movement, attention, sense of agency, sensory processing, emotion, and awareness of internal bodily signals.

These findings help us understand FND, but there is no brain scan or single neurological abnormality that can currently diagnose the condition. Current research increasingly looks at how different systems interact rather than searching for one abnormal brain region that explains FND. There are still many unanswered questions.

Attention, Movement, and Prediction

Attention appears to be particularly important in functional movement symptoms.

Most everyday movement happens with relatively little conscious effort. When we walk across a room, we usually do not think about every muscle or direct each part of the movement.

In functional movement disorders, symptoms may change when attention is directed toward or away from the movement. Variability and distractibility can also be useful positive signs during neurological examination.

This has influenced FND-informed rehabilitation. Treatment may include redirecting attention away from the mechanics of movement, encouraging more automatic or goal-directed movement, and practicing activities in ways that are closer to ordinary life.

Another area of research looks at predictive processing.

The brain continuously combines incoming sensory information with prior experience, expectations, and context to organize perception and movement.

Researchers are studying whether differences in these processes may contribute to symptoms in FND, including changes in movement, sensation, attention, and a person’s sense of control over movement.

Predictive processing is an important research framework, but it remains one model among several and does not fully explain FND.

Where Do Stress and Trauma Fit?

The relationship between FND, stress, and trauma is complicated. Research has found higher rates of stressful life events and childhood adversity in some FND populations. Anxiety, depression, PTSD, and other mental health concerns may also occur alongside FND. But trauma is not required for the diagnosis.

Many people with FND do not identify a significant trauma history, and psychological stress should not be assumed to be the cause of someone’s symptoms. The importance of trauma also appears to vary across FND subtypes. For example, trauma and adversity have been particularly well documented in people with functional seizures, while other pathways may be more relevant in other forms of FND.

For one person, stress may clearly affect symptoms. For another, symptoms may begin around an illness, injury, pain, surgery, or another physical change. Sometimes there is no obvious starting point. A person’s history can be relevant without becoming the explanation for everything that is happening.

There is also another side of this that can easily be missed: having neurological symptoms is stressful. Someone who suddenly loses strength, experiences functional seizures, or cannot rely on their walking may understandably begin paying much closer attention to what is happening in their body. They may worry about when symptoms will happen again, whether they can go somewhere alone, whether they can trust their body, or whether something has been missed medically.

Fear of symptoms, avoidance, disrupted sleep, changes in activity, and the emotional impact of losing function can all become part of the picture, regardless of what originally contributed to the FND.

What Does Treatment Look Like?

Treatment depends on the person’s symptoms and circumstances. A clear explanation of the diagnosis is an important starting point. People need to understand what has been found clinically, why the diagnosis has been made, and that their symptoms are real and involuntary.

For functional motor symptoms, FND-informed physical and occupational therapy are important parts of treatment. Rehabilitation may include movement retraining, changes in attentional focus, increasing everyday activity, and strategies for managing symptoms.

Speech and language therapy may also be useful when FND affects speech, voice, swallowing, or related functions.

For functional seizures, psychological treatments have growing evidence. Treatment should also include assessment for co-occurring epilepsy and other medical or psychiatric conditions when relevant.

There is not one treatment that works for everyone. Current evidence supports individualized care, often involving several disciplines depending on the person’s symptoms and needs.

Where Somatic Practice and Psychotherapy May Fit

Psychotherapy does not require assuming that FND was caused by trauma or psychological conflict. My role is not to determine the neurological cause of the symptoms. I am more interested in what happens around them.

Someone may notice that they brace when symptoms increase, become very focused on one part of the body, stop certain activities because they are afraid of triggering symptoms, or become overwhelmed by uncertainty about what a symptom means.

Somatic practice and psychotherapy can offer another way of exploring these experiences. This might include noticing changes in sensation, tension, breathing, attention, or movement; differentiating between physical sensations; or becoming more aware of what happens before, during, and after a symptom changes.

These observations do not tell us what caused the FND, and somatic practice is not a substitute for FND-informed neurological or rehabilitation treatment. These observations may help identify patterns that are useful to work with alongside that care.

For someone with a trauma history, trauma may also be important to address. For someone without that history, there is no reason to assume trauma is part of the explanation. The point is not to decide that the symptoms are psychological. It is to understand what may be useful to work with alongside appropriate neurological and rehabilitation care.

A More Complete Understanding of FND

FND sits in an area where the old divide between physical health and mental health is not very helpful. Research is giving us a better understanding of movement, sensation, attention, agency, prediction, and other neurological processes involved in FND.

At the same time, FND is heterogeneous. The same combination of factors does not explain everyone’s symptoms.

Stress and trauma may matter for some people without providing a universal explanation.

For me, the important question is not whether someone’s experience belongs entirely to physical health or mental health. It is how we can understand the whole picture without dismissing the physical symptoms or reducing them to one explanation.