Trouble neurologique fonctionnel

What are functional neurological disorders?

The medical world has made some great advances in the last thirty years or so. But in recent times it has become apparent that there are a lot of symptoms out there that doctors just can't put their finger on.

When someone has problems or symptoms that don't fit into a specific diagnosis or can't be shown on a blood test or scan, doctors often use the term 'functional'. Some patients don't like this term because it can sound like they're being dismissed; however, other patients find it helpful to be given some sort of label. Patients who have been told they have functional disorders have begun to form groups to help understand their problems: this is very helpful as they can compare symptoms and help each other become aware of treatments.

Common symptoms that are experienced by people with a functional neurological disorder include:

• Tingling in the hands or feet.

• Des tremblement in one or both arms.

• Maux de tête ou les migraines.

• Changes in eyesight, like vision floue or seeing flashing lights.

• Difficulty with la mémoire or doing complicated tasks.

• Problèmes dormir, including sleeping too much or too little.

• Changes to personality, like becoming more irritable or depressed.

• Convulsions or shaking of the body.

• Pain in the arms or the legs that cannot be controlled by normal painkillers.

• Problems with the bowels and the bladder, like passing water more than usual or having difficulty moving one's bowels.

• Sudden fainting or loss of consciousness.

• An inability to move an arm or a leg properly, or a heavy feeling down one side of the body.

• Problems concentrating.

Specialists have found two broad sub-types that are the most common - motor problems and seizures.

The difficulty is many of these symptoms are present in other neurological conditions like la maladie de Parkinson, sclérose en plaques et épilepsie. That is why a doctor will usually rule out these conditions before considering a functional neurological disorder.

This is an area of contention because doctors can't find a definite 'cause': all blood tests, scans, and other investigations are normal. But the person certainly isn't 'making it all up': they are not malingering or faking.

One theory is that the brain, although wired up OK, doesn't control movements or receive sensations normally: hence the unusual movements like tremors, and the abnormal feelings like tingling or pain.

Many people who do not have functional neurological disorders themselves often attribute the person's symptoms to stress or emotional problems. This is valid in some cases but may be over-simplifying things. Many people with functional symptoms have had an emotional or psychological trauma in the lead-up to them developing symptoms, but others haven't. Sometimes two things coincide: a physical illness like the flu or a bad viral illness, coupled with a recent emotional trauma.

This is therefore an area where modern medicine, despite its many advances, cannot fully explain something that affects a large number of people. Another difficulty with talking about 'causes' is that the language used (with words like 'psychological', 'stress' and 'trauma') is often interpreted differently by different people.

Doctors from almost every specialty will be familiar with patients whose symptoms do not fit a specific diagnosis or a 'box'. It is hard to quantify exactly how many people in society experience these symptoms, because many may not consult a doctor.

What is known for certain is that the symptoms are debilitating: people with functional neurological disorders rate their condition as just as devastating as people with Parkinson's disease, for example. And most family doctors, or GPs, will know how these problems can often severely affect a person's ability to live a normal life.

Most people with functional neurological disorders find that medications do not help. It is tempting to take medications and, indeed, it is tempting for doctors to prescribe them, but each medicine carries its own set of side-effects.

Treatments generally consist of managing the symptoms and finding a way of living with them and understanding them.

Rehabilitation with physiotherapy or occupational therapy has been shown to be helpful for the more 'movement' side of functional neurological disorders, like weakness or tremors.

For the more 'sensory' type of symptoms like pain and seizures, psychotherapy and la thérapie cognitivo-comportementale can help.

In general, doctors who work in the field and patient support groups do not recommend medications for the symptoms of functional neurological disorders. An example is painkillers: many patients end up on huge quantities of pain relief which hardly ever helps; each painkiller has side-effects too and is often addictive.

Unfortunately, because conventional NHS doctors often can't help a great deal, there are a lot of practitioners with dubious qualifications out there. They often promise great cures, at vast expense. Vulnerable patients can then end up spending huge sums of money on an unattainable goal. Please be careful: try to find a reputable doctor who works in the field in a state-funded system (like the NHS) or who is covered by your insurance.

In general, the more you understand and know about functional neurological disorders, the better you can manage your symptoms. Try to find a local self-help group and meet others with the condition to find out what works for them.

Thankfully functional disorders are now being taken more seriously by the medical world than ever before. It may be that a classification system will be set up to categorise different types of the condition. That way, treatments can be tested in trials and more can be learnt about the condition.