The term "Functional Movement Disorder" is a relatively new one. It is a term to characterize real and problematic disorders of
movement that, although not faked or imagined, are not due to an underlying neurological disease. These are conditions that are not infrequently seen in specialty movement disorder clinics (up to 15% of
new consultations), wherein a patient comes in with a disorder of movement or abnormal movements which interfere with their function, but careful examination is able to exclude that the movement disorder
is due to damage in the nervous system. Although the cause or trigger for the dysfunction is often never found, these disorders are not due to any brain pathology or lesion. These patients can present
with a wide spectrum of different movement disorders that range in their severity and impact. An analogy which is useful in helping both doctors and patients understand these puzzling conditions is that
they represent a software problem and that the hardware is intact.
As a result of the difficulty that doctors, who are not specialists in movement disorders, have in accurately identifying this
condition, patients have often seen multiple physicians and undergone extensive investigation without an explanation for their problem. Often when conditions take a long time to diagnose, patients
inevitably begin to worry they may be suffering a rare and perhaps life threatening condition. Not infrequently they may have difficulty accepting this explanation and will continue to seek an answer
Just like Parkinson's disease and migraine, there are standardized clinical criteria that allow these conditions to be accurately
diagnosed by specialists at the bedside (often without laboratory tests or scans). The movement disorder neurologist, through careful history and clinical examination, is able to check and confirm the
brain pathways are all connected (the "hardware" is intact). Being able to demonstrate this allows the conclusion that the movement disorder is the result of a disorder of the connectivity or networking
of the brain (a "software" problem). This means the disorder, unlike many other movement disorders (eg Parkiinson's disease, Essential Tremor) has the potential to be reversed leading to recovery.
Once diagnosed, laboratory investigations (used to exclude other conditions) are usually no longer required and the process of
helping the patient understand the condition and treatment can begin. One treatment regime attempts to slowly retrain or reprogram movements to try to restore normal brain functional connections.
Medications are not usually of any benefit.
It is always important in all movement disorders to exclude any depression or other underlying psychological disorder as these
need to be treated when evident. In cases with functional disorders often no such problem is present. If anything patients often appear less impacted emotionally by disability associated with these
movement disorders than equally disabled patients with degenerative diseases. Depressive symptoms can however be associated and should be treated aggressively when identified.
There is an excellent web resource that describes these conditions in detail that is recommended reading. This can be found at www.neurosymptoms.org/. The part of the website specifically relating to movement disorders can be found at www.neurosymptoms.org/movement-disorders/4533053142 and the page on helping understand this diagnosis www.neurosymptoms.org/understanding-it/4533198106 is a must read. There is a pamphlet avaialble from this site that can be downloaded and should also be read.
Click here to download the Neurosymptoms web site pamphlet on functional movement disorders