Functional Neurological Disorder (FND)

What is functional neurological disorder?

Functional neurological disorder (FND) is a condition where signals between the brain and body have difficulty sending and receiving properly. The symptoms are not caused by structural damage to the brain or body, but by disruptions in how the nervous system functions. FND is a common cause of neurological symptoms and can occur alongside other health conditions. Because the disorder affects the nervous system's signaling, it can involve nearly any part of the body the nervous system controls. Symptoms may come and go throughout the day or week, or they may persist.

What are the common signs and symptoms of FND?

• Vision problems (double vision, blurriness or blindness)
• Speech problems (slurred speech, stuttering or loss of speech)
• Numbness or loss of sensation
• Hearing problems
• Memory problems
• Difficulty concentrating
• Pain, including chronic migraine
• Fatigue
• Weakness or paralysis
• Tremors, spasms, jerkiness or tics
• Involuntary repetitive movements
• Difficulty walking
• Loss of balance
• Difficulty swallowing
• Seizures or episodes of shaking and loss of consciousness (not caused by epilepsy)

How is FND diagnosed?

There is no single test to confirm FND. Diagnosis is based on a patient's history, symptoms and physical exam, with neurologists looking for specific clinical signs, such as Hoover's sign, which reveals functional leg weakness. Doctors may also test for entrainment by moving the unaffected or less affected limb at a certain rhythm to see if the limb experiencing tremors responds.

Additional testing, such as an EEG (electroencephalography), EMG (electromyography) or MRI, may be ordered to rule out other conditions. The healthcare team will look for specific triggers and patterns to support the diagnosis.

How is FND treated?

FND treatment is multidisciplinary. The following medical experts are often involved:

• Neurology: A neurologist confirms a diagnosis and monitors the patient for new neurological symptoms. The neurology team educates families and coordinates care.
• Psychiatry: A psychiatrist can identify and treat psychiatric conditions that occur alongside FND utilizing medication and/or therapy. Psychotherapy, including cognitive behavioral therapy (CBT), can help patients manage triggers, understand thought patterns and retrain signals in the brain to better control FND.
• Physical therapy: A physical therapist helps patients with motor control, balance, coordination and strength. It can also help reduce functional weakness, tremors and spasms.
• Occupational therapy: An occupational therapist works with patients to improve daily functioning with pacing, sensory and emotional regulation and practical system management.