What is functional neurological disorder?
Written in association with:
Published: 09/01/2025
Edited by: Jessica Wise
Functional neurological disorder is rare condition where there is a dysfunction in the nervous system that disrupts how the brain sends signals to the rest of the body. In this article a consultant psychiatrist explains functional neurological disorder, how it can occur, and what possible treatments are available.
What is functional neurological disorder and what causes it?
Functional neurological disorder (FND) refers to a group of neurological symptoms that cannot be traced back to a certain structural or biochemical abnormality in the brain and nervous system. MRIs or CT scans will not show any visible injury or disease (like a tumour) in the brain and nervous system – instead, it is theorised that the symptoms stem from disruption to the brain networks.
Those who are at a higher risk of developing FND include those who have a family history or a childhood history of illness and trauma (particularly from sexual abuse). There is no way to definitively avoid or prevent FND, as everyone has the potential to develop it and it can be triggered suddenly.
It used to be called ‘conversion disorder’, as it was thought that the symptoms were a physical manifestation of psychological illness and distress. Rather, it is more accepted today that psychological distress may be comorbid with FND, but not necessarily present.
What are the signs of functional neurological disorders?
The symptoms of FND include:
Muscle weakness or paralysis Sensory disruptions (such as double vision, hearing loss, touch numbness) Abnormal movement (such as tremors, abnormal gait, and loss of balance) Difficulty swallowing or feeling as though there is an obstruction in the throat Speech problems (such as slurring, sudden hoarseness or unintentional mutism) Spasms and non-epileptic seizures Brain fog, memory issues, and incorrect speechIt may also be accompanied by chronic pain and fatigue. The symptoms can have a sudden, unpredictable onset and may not constantly be present, thus barring patients from living their everyday lives.
How is functional neurological disorder diagnosed?
The symptoms of FND overlap with some other neurological conditions such as epilepsy, multiple sclerosis, dystonia, or Parkinson’s, which means that many patients may be under- or misdiagnosed.
Diagnosing FND requires a thorough review of the patient’s personal and familial medical history, a physical exam, and observation of the patient’s behaviour and mannerisms.
Some signs that can indicate FND to a specialist include alexithymia (difficulty describing own feelings), irregular distribution of symptoms (where they occur in the body), Hoover’s sign (inconsistency between automatic and voluntary hip extension), give way weakness (inconsistent muscle power).
Imaging tests may be utilised to rule out other neurological conditions or diseases, like MRIs, CT scans, or electroencephalograms.
How is functional neurological disorder treated?
It is important for doctors to validate the patient's experience with FND, so to treat FND, doctors have to take a multidisciplinary, patient-centred approach, combining aspects of medicinal, psychological, and physiological care to improve their quality of life.
Speech therapy and physiotherapy can help the patient regain control of their muscles and restore functionality. Occupational therapy can help patients learn how to continue their daily activities and lives while grappling with FND. Psychotherapies like cognitive behavioural therapy and dialectical behavioural therapy can help the patient process underlying trauma and emotional distress that can exacerbate their symptoms. Medications such as antidepressants, pain relief, and anti-anxiety medicine may be applicable.With multidisciplinary care, a full recovery from FND is possible, or at the very least, a significant improvement of the symptoms.
If you are struggling with an unknown neurological disorder, you can consult a specialist on Top Doctors