Several research projects on FND are funded by the National Institutes of Health (NIH, the leading supporter of biomedical research in the world) and its National Institute of Neurological Disorders and Stroke (NINDS, the leading federal funder of research on the brain and nervous system). Among NINDS research, scientists are studying the neurobiology of FND and nonepileptic seizures, as well as any clinical association of the effects of the COVID-19 pandemic on individuals with functional movement disorder.
Scientists funded by the NIH are working to better understand the underlying neuropathology of FND and hope to develop neuroimaging biomarkers—signs that may indicate risk of developing a disease or be used to monitor its progression—for FND and nonepileptic seizures. Among other research, investigators hope to better treat PNES and to test medications for PNES.
Clinical research on FND can be found at ClinicalTrials.gov, a database of thousands of research studies in the U.S. and around the world. Enter “functional neurological disorder” into the “Condition or disease” field to identify current and past trials. You can also indicate country and state to find trials near you.
Functional neurologic disorder (FND), also called conversion disorder and functional neurologic symptom disorder, refers to a group of common neurological movement disorders caused by an abnormality in how the brain functions. There is no structural damage; the brain is unable to send and receive signals properly and there is a disconnection in the function of the lobes and emotional processing. Someone with FND can function normally, they just can’t at that moment. Memory, concentration, cognition, and the processing of sensations also can be affected. FND can involve any part of the body.
Anyone can develop FND but it is more common in women. An estimated 4 to 12 people per 100,000 will develop FND. The exact cause of FND is unknown. Fundamental causes may involve biological factors (such as early childhood trauma and early life stress, emotions,anxiety, witness to violence, maltreatment, or childhood sexual abuse) or sociological factors (including interpersonal relationships and stress). FND sometimes may result from a somatic symptoms disorder (characterized predominantly by multi-system symptoms that are associated with distress and/or dysfunction and look like a physical illness).
Psychogenic nonepileptic seizures (PNES) may look like generalized or other forms of epileptic seizures but are caused by brain dysfunction and not by abnormal electrical signaling in the brain. There may be episodes of movement, sensation, and behavior similar to an epileptic seizure and a temporary loss of attention or memory lapse. Some individuals with PNES may have confusion or loss of consciousness without shaking or a feeling of being “disassociated” (or somewhat disconnected) from thoughts or feelings or from the environment. PNES mostly affects women and often begins in young adulthood.
Functional movement disorder (motor FND, affecting movement of the body) symptoms are common and may include:
- Leg and arm weakness or paralysis
- Sudden, brief involuntary twitching or jerking of a muscle or group of muscles (called myoclonus)
- Involuntary muscle contractions that cause slow repetitive movements or abnormal postures (called dystonia)
- Problems with walking motion (gait), posture, or balance
- Spasms and contractures (where the tendons become fixed in awkward or uncomfortable positions)
- Muscle stiffness
Other symptoms may include:
- Speech difficulties, such as sudden onset of stuttering or trouble speaking
- Problems with seeing or hearing
- Pain (including chronic migraine)
- Extreme slowness and fatigue
- Numbness or inability to sense touch
There are no specific treatments for FND but there are treatments for some of its symptoms.
Medications can treat pain, anxiety, depression, insomnia, or headache that may occur. Any anti-seizure medications prescribed to treat nonepileptic seizures should be discontinued, as the attacks of PNES and those of epilepsy are not the same and are treated differently.
Psychotherapy involves having the person talk with a licensed and trained mental health professional about negative or troublesome emotions, behaviors, and thoughts. Cognitive behavior therapy can help a person modify thought patterns to change emotions, mood, or behavior. Relaxation and mindfulness exercises can help reduce stress and for some people hypnosis can induce relaxation and lessen FND symptoms.
Physical, speech, and occupational therapy can help. Physical therapy can treat muscle weakness or impaired movement and help the person relearn normal movement control. Occupational therapy is designed to improve how the person functions and performs everyday tasks. Speech therapy may be needed if the ability to speak or swallow is affected.
Redirecting attention from the abnormal movement, such as having a conversation while the movement is taking place or tapping by an unaffected arm or leg, can lessen movement or other symptoms.
Other forms of treatment may include transcranial magnetic stimulation (which uses magnetic fields generated outside the skull to stimulate nerve cells in the brain) to treat depression and anxiety and transcutaneous electrical stimulation (which uses low-voltage noninvasive electrical current to activate nerves) to relieve pain. Lifestyle changes such as exercising, eating a balanced diet, participating in relaxation exercises, and getting enough sleep also can help reduce stress and anxiety.
For some people, symptoms of FND are short-lived while for others they may last for years. Early diagnosis and treatment can help lessen symptoms and aid in healing. Relapses and flare-ups often recur, despite treatment.
In some people with PNES, seizures may be frequent and prolonged. With proper treatment, PNES may cease in some individuals or reduce in frequency. Children and adolescents with PNES tend to have a higher rate of recovery.