What is FND?


Functional Neurological Disorder (FND) is a very common reason people consult with a Neurologist. It can cause a range of very debilitating symptoms, it is an abnormal functioning of the nervous system. The symptoms depend on what part of the nervous system is affected. The symptoms can include:

  • Sensory disturbances, such as buzzing, tingling, burning pain, that can affect any part of the body
  • Chronic fatigue and forgetfulness
  • Weakness and abnormal patterns of movement, which can include tremors, abnormal positioning of limbs and walking difficulties
  • Functional seizures
  • Visual disturbances and difficulty with speech
  • Bladder and bowel problems


The symptoms can be just as disabling as some serious neurological disorders such as Parkinson’s disease and Multiple Sclerosis. However, as no structural damage can be seen on MRI scans, as in other disorders, patients are often told they are anxious and that there is nothing to worry about. Functional Neurological Disorder is a very real and very troubling disorder.

Features on a clinical history are used to diagnose Functional Neurological Disorder, the main part of the diagnosis is ruling out serious diseases such as Multiple Sclerosis. However, sensory disturbances may be present such as buzzing and tingling but no clinical weakness. The symptoms may go away for a period of time and come back, indicating that it is more related to the functioning of the nervous system. With weakness and abnormal patterns of movement, again symptoms may present but then they may disappear for a period of time, there may be a period where the patient improves. Alternatively for an example in leg weakness, if a leg is moved in a different way the power of the leg returns, which indicates the nervous system is working but just in a different way.