The 4 Main Characteristics of FND: Entrainable, Redirectable, Distractible, Suppressible

Functional Neurological Disorder (FND) describes a problem with how the brain receives and sends information to the rest of the body. One way to picture it is losing a Wi-Fi signal: in FND there the structures to produce the signals are there, they just aren’t communicating well. We get poor signal around storms (tension, fatigue, anxiety, illness) and better signal with clear skies (routine, regulation, rest). Symptoms include limb weakness, tremor, functional seizure, numbness, blackouts, difficulty walking, dizziness, and speech changes.

Chronic pain, persistent fatigue, cognitive fog and sleep problems frequently appear alongside those symptoms. What ties these experiences together is not a specific damaged area of the brain but a disruption in how the nervous system produces and controls movement, sensation, and attention.

Clinicians who examine people with FND look for specific findings called positive clinical signs. These are features that show up during an exam and point toward FND rather than another neurological condition. A 2025 review by Mavroudis and colleagues' groups several of these signs together. Four related features come up again and again in conversations with patients: FND symptoms are entrainable, redirectable, distractible, and suppressible.

What "Positive Signs" Means in FND

In neurology, a positive sign is something that is present because of a condition, rather than something missing because of lost function. Weakness with no reflex change is a negative finding. A tremor that changes rhythm when a person matches the rhythm of the therapist is a positive sign, because the tremor itself reveals how the nervous system is misbehaving.

Entrainment and distractibility are the two most widely documented examples of positive signs in FND. Redirectability and suppressibility are closely related patterns that clinicians and patients describe in the same family. Together they explain a question families ask constantly: how can a symptom be severe one minute and barely visible the next?

1. Entrainable

Entrainment means one rhythm takes on the timing of another. In FND, a functional tremor may drift into the frequency of a voluntary tapping movement performed with a different body part or mirror what the therapist is doing. The tremor does not hold its own beat. It follows the beat of the task.

Why Entrainable Symptoms Matter

Entrainment is useful because it is difficult to produce on purpose. It reflects how movement is generated and monitored in the brain rather than damage to nerves or muscles. For patients, it can be a relief to learn that the pattern has a name and that it is recognized as a genuine clinical finding.

2. Redirectable

Redirectable describes a symptom that shifts when attention is moved to a different task or a different part of the body. Weakness that feels complete during one movement may ease when the same muscles are used automatically, such as reaching for a cup without thinking about the reach. A leg that drags during a slow, deliberate step may swing more normally during a faster, less monitored walk.

This is one of the most confusing characteristics for people living with FND, because it can look like inconsistency or exaggeration from the outside. It is neither. An impairment of self-agency, the sense that one is not fully in control of voluntary movement, is a defining characteristic of FND. The person is not redirecting the symptom on purpose. The symptom simply responds to where attention lands.

3. Distractible

Distractibility means a symptom reduces or disappears when attention is pulled elsewhere. A functional tremor may quiet while the person counts backward from a hundred. A functional gait problem may improve while the person carries on a conversation. The symptom returns when attention shifts back to it, and that return is part of the pattern.

Why Distraction Changes FND Symptoms

Attention is one of the inputs the brain uses when it produces movement. When attention is occupied by a demanding task, the movement system runs with less of that conscious monitoring, and the symptom can temporarily ease. This is a normal feature of how the nervous system prioritizes tasks, not a trick the person is performing.

4. Suppressible

Suppressible means a symptom can be held back briefly when a person concentrates hard on it or performs a movement in a specific way and then returns once that effort stops. A functional tremor might pause for a few seconds during intense concentration. A functional weakness might briefly allow a stronger contraction when the person is given a precise instruction.

Suppression Is Not Willpower

Suppression is short lived and effortful. It does not mean the symptom was invented, and it does not mean the person can simply switch it off for good. What it shows is that the symptom is generated within networks that respond to attention, expectation, and context, which is exactly why occupational therapy and other rehabilitation approaches can influence it.

What These Characteristics Do Not Mean

FND is a real disorder with a neurological basis. There is no damage to the structure of the brain, but that does not make the symptoms less genuine, and it does not make them something a person chooses or controls. The defining feature is a breakdown in self-agency, the ordinary sense of owning and controlling your own movement and capacity.

Because FND symptoms change with attention, people are sometimes told their symptoms are imagined or that they are seeking attention. Those conclusions are not supported by how the condition works. A symptom that varies with distraction is displaying a recognized positive sign, and clinicians use those signs to reach an accurate diagnosis.

How Occupational Therapy Uses These Characteristics

Understanding that FND symptoms are entrainable, redirectable, distractible, and suppressible gives rehabilitation a clear direction. If a symptom changes with attention and context, then therapy can deliberately work with attention and context to retrain movement.

Therapy for FND often involves graded movement practice that keeps attention on a meaningful task rather than on the symptom itself. A person might work on walking while solving a problem out loud, or on hand function while engaged in a meaningful activity. Over time, the goal is to make reliable movement or nervous system regulation more automatic, so it depends less on conscious monitoring and more on the brain's ordinary movement programs. This is a gradual process, and progress is typically measured in small gains that build. This is Rewiring.

RewireOT is a specialized outpatient occupational therapy clinic in Ellisville, Missouri, founded by Jason Kreuzman, MOT, OTR/L that focuses on treatment specifically for Functional Neurological Disorder. At RewireOT, understanding and planning around these 4 key features of FND are integrated into personalized rehabilitation. Follow the link to learn more and inquire about in-clinic or virtual treatment. serving clients across Missouri and Illinois.

Frequently Asked Questions

What does it mean when an FND symptom is distractible?

A distractible symptom fades or eases when attention moves to something else, such as counting backward or completing a demanding task with another part of the body. A functional tremor may quiet during that task and return afterward. Distractibility is one of the positive clinical signs that can be used as a tool for nervous system calming but should not be the sole treatment. 2025 review by Mavroudis and colleagues. It reflects how the nervous system generates the symptom, not effort or acting.

Are entrainable symptoms a sign that someone is faking?

No. Entrainment is a recognized clinical finding, not evidence of pretending. FND involves a genuine disruption in how the brain produces movement and sensation, and the defining feature is a reduced sense of control over voluntary movement. A tremor that follows the rhythm of a tapping task is showing a real pattern in the nervous system. It is not something a person can decide to create or stop. But it can be influenced during intentional FND rehabilitation.

Can FND symptoms be suppressed on purpose?

Suppression is usually brief and requires real effort, and it does not mean the person can simply turn the symptom off permanently. Someone may hold a tremor back for a few seconds during intense concentration, then have it return. This short-lived control is useful information for therapy, because it shows the symptom responds to attention and can potentially be retrained with practice.

Who should evaluate these characteristics?

These signs are used in diagnosis by a Neurologist or trained Psychiatrist, but members of your FND treatment team should all have awareness of these features and integrated them you’re your personalized FND rehabilitation. Change in these symptoms is one of the constants with FND. In the St. Louis area, RewireOT in Ellisville, Missouri provides occupational therapy for people already diagnosed with FND and related conditions.

Do all four characteristics apply to every FND symptom?

Not necessarily. People with FND vary widely, and their symptoms may show some of these patterns and not others. Entrainment and distractibility are the best documented positive signs, while redirectability and suppressibility describe related patterns clinicians observe. What matters most is that a trained clinician identifies the pattern in your specific presentation and builds a treatment plan around it with you.

15800 Manchester Rd., Cornerstone Building, Studio B, Ellisville, MO 63011 (636) 254-7760

RewireOT Blog

Privacy Policy

FND Treatment Missouri/Illinois

Occupational Therapy Pain Management