Functional Neurological Symptom Disorder (FNsD) is a neurological disorder for which very little is currently known. It is an umbrella term for a variety of symptoms which look similar to those caused by neurological conditions such as
Multiple Sclerosis (MS) or
Parkinson's Disease, including weakness, fatigue and seizures. It is currently believed that Functional Neurological Symptom Disorder arises from a problem with the patient's
Central Nervous System, which is not sending and receiving signals correctly. The brain of a patient with Functional Neurological Symptom Disorder is structurally normal, but functions incorrectly.