Functional Neurological Disorder (FND) or conversion disorder
What is the FND?
Functional Neurological Disorder (FND), previously known as conversion disorder, is a condition in which a person experiences neurological symptoms that suggest a disease of the nervous system (such as tremors, paralysis, seizures, or balance problems) but without any detectable structural damage to the brain or nerves. This disorder is related to the functioning of the nervous system and how the brain and body send and receive signals.
In other words, medical tests do not reveal any physical or anatomical cause for these symptoms. However, the symptoms are real and can significantly impact quality of life, in ways similar to other neurological conditions. FND can affect children, adolescents, and adults alike.
Unlike some other neurological conditions, recent promising studies show that FND may be reversible.
How is FND diagnosed?
Diagnosis of FND, made by a neurologist, relies on ruling out other neurological causes AND identifying characteristic clinical signs. According to the DSM-5TR, four main criteria must be present:
- There must be at least one neurological symptom (involving voluntary motor or sensory function).
- This symptom must be incompatible with a known neurological condition.
- Another medical condition does not better explain the symptom(s).
- Significant functional impairment must be observed.
Additionally, besides incompatibility, the inconsistency and incongruence of the symptom(s) must be identified.
What are the risk factors?
Although several risk factors may contribute, it is important to note that FND can occur without an obvious trigger. There is no single necessary and sufficient cause to develop FND. The risk factors involved in FND are varied and differ significantly between individuals:
- Psychological or emotional stress can increase the risk of developing FND. Sometimes, FND appears following a stressful event.
- Anxiety and depression increase the risk of developing functional neurological symptoms. Anxiety can sometimes exacerbate these symptoms.
- Physical trauma or neurological diseases (such as stroke, migraine, etc.) can trigger or worsen FND. Sometimes, a real symptom (such as pain or weakness) may persist beyond its original cause.
- Personality traits, such as a tendency towards heightened body vigilance (being overly attentive to bodily sensations), can make someone more vulnerable to these disorders.
- Cultural or social expectations may play a role. For instance, in some societies, physical symptoms may be more accepted or understood than psychological symptoms, encouraging the expression of emotional or psychological conflicts as physical symptoms.
While FND is not directly hereditary, a predisposition to certain psychological traits (like heightened sensitivity to stress) might be passed down genetically.
These risk factors do not necessarily lead to FND, but they may increase the likelihood of developing symptoms. It is important to remember that each person is unique, and the combination of factors leading to FND can vary from one individual to another.
What are the main types of FND?
FND can present in various ways with a wide range of symptoms. Here are the main types of FND:
- Functional motor disorder: This type of FND affects voluntary movement and manifests as movement disorders.
- Paralysis or muscle weakness in a part of the body (e.g., a leg or arm).
- Gait disturbances (difficulty walking, unstable or abnormal gait).
- Tremors, muscle spasms, or involuntary contractions.
- Functional dystonia (abnormal and rigid positioning of a part of the body).
- Non-epileptic seizures: These seizures resemble epileptic seizures but are not caused by abnormal electrical activity in the brain. Seizures can be triggered by stress or strong emotions and show no abnormalities on an electroencephalogram (EEG).
- Functional sensory disorder: This type affects sensations and may result in loss of sensation or abnormal sensations in certain parts of the body.
- Loss of sensitivity to touch, pain, or temperature in a specific area.
- Tingling or numbness (paresthesias).
- Functional visual disturbances (blurred, double vision, or vision loss without an organic cause).
- Functional speech disorder: This type affects the ability to speak fluently and coherently.
- Difficulty articulating words (dysarthria).
- Broken or weak voice (dysphonia).
- Complete loss of voice (aphonia).
- Functional cognitive disorders: These disorders affect concentration, memory, and other cognitive functions.
- Difficulty concentrating or recalling recent information.
- Feeling of mental confusion or brain fog.
- Inability to perform simple cognitive tasks.
These different types of FND can appear alone or in combination in the same person. A multidisciplinary treatment approach, combining psychotherapy, physical rehabilitation, speech therapist as needed and sometimes medication, is generally recommended to improve symptoms.
What are the treatments for FND?
Since FND has its own clinical characteristics, it requires a multidisciplinary approach (intensive or non-intensive) targeting both the physical and psychological aspects of the disorder. There is no single treatment, but a set of personalized strategies can help people manage their symptoms and improve their quality of life. The goal is to retrain the brain to control motor and sensory functions in a normal and appropriate manner.
Here are the main treatments used for FND:
- Education and explanation of the disorder: It is crucial for individuals to understand what FND is, as misconceptions about their condition can worsen symptoms. A reassuring and clear explanation that the symptoms are real but reversible is often the first step in treatment.
- Physical rehabilitation and functional therapy:
- Physical therapy: For motor disorders, physical rehabilitation is essential to relearn how to move correctly. It helps individuals restore normal movement and reduce protective or avoidance behaviors.
- Occupational therapy: It can help manage daily activities and improve independence in individuals suffering from functional limitations.
- Psychological therapy: Different types of therapies (cognitive-behavioral, mindfulness-based, etc.) can help reduce erroneous beliefs about the illness, manage stress and emotions, and improve resilience in the face of symptoms.
- Medication: While medications do not directly treat FND, they can be helpful in managing associated symptoms such as anxiety, depression, or insomnia.
Other alternative therapies such as hypnotherapy, the use of biofeedback, and mirror therapy (a treatment aimed at tricking the brain) are currently being studied.
Support from family and/or loved ones is often crucial for recovery. A better understanding of the disorder by those around the patient can help reduce stigma and misunderstanding.
Treating functional neurological disorders (FND) is often a lengthy process, and relapses may occur. However, an integrated and individualized approach that combines different types of care yields better results in helping individuals regain a better quality of life and reduce the frequency and severity of symptoms.
At Neuro-Concept, therapists have undergone training to treat functional neurological disorders, and their multidisciplinary approach, combining physical and mental health, has proven effective. While each patient is at least supported by a mental health occupational therapist, a neurologist, and a kinesiologist, the uniqueness of this program lies in the individualization of the treatment plan, offering a “customized” approach based on each patient’s specific situation, which can vary significantly from one individual to another.
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