Functional neurologic disorder (FND), also known as functional neurological disorder or conversion disorder, is a medical condition in which patients experience neurological symptoms such as weakness, movement disorders, sensory symptoms, and blackouts. FND is related to how the brain functions, rather than damage to the brains structure such as from a stroke, multiple sclerosis, infection, or injury. The exact cause of FND is unknown, but it may be triggered by a neurological disorder or by a reaction to stress or psychological or physical trauma.
FND can involve any part of the body, and symptoms may appear suddenly, increase with attention to them, and decrease when the person is distracted. FND has two primary categories: psychogenic nonepileptic seizures (PNES) and functional movement disorder (FND). There are many types of FND, with a diverse mix and range of neurological symptoms and disorders.
Diagnosis of FND is dependent on positive features from the history and examination. Testing and diagnosis usually involve a neurologist but may include a psychiatrist or other mental health professional. Conventional tests such as MRI brain scans and EEGs are usually normal in patients with FND. For many patients with FND, accessing treatment can be difficult, and availability of expertise is limited. Early diagnosis and treatment, especially education about the condition, can help with recovery.
Associated conditions of FND include higher rates of depression and anxiety in patients with FND compared to the general population, but rates are similar to patients with other neurological disorders such as epilepsy or Parkinsons disease. Stressful life events and childhood neglect were found to be significantly more common in patients with FND than the general population, although many patients report no stressors. FND can be difficult for patients, their families, and doctors to understand, and some medical professionals are uncomfortable explaining and treating patients with functional symptoms.
There are several resources available for those with FND, including the Neurosymptoms FND Guide, My FND app, FND Hope UK, and FND Action.
