Download FND app Android Aapp IoS App
FND Links Feedback Donate Language
  • English
Home / Symptoms / FND Symptoms / Functional Limb Weakness

Functional Limb Weakness

What is functional limb weakness?

Functional limb weakness is weakness of an arm or leg due to the nervous system not working properly, rather than damage or disease of the nervous system.

Patients with functional weakness experience symptoms of limb weakness which can be disabling and frightening such as problems walking or a ‘heaviness’ down one side, dropping things or a feeling that a limb just doesn’t feel normal or ‘part of them’.

To the patient and the doctor it often looks as if you have had a stroke or have symptoms of multiple sclerosis. However, unlike these conditions, with functional limb weakness, there is no permanent damage to the nervous system which means that it can improve or even go away completely.

How is a diagnosis of functional limb weakness made?

The diagnosis of functional weakness is usually made by a neurologist or stroke physician.

When they are examined, the doctor usually finds a pattern of weakness typical of this problem and does not find changes in reflexes or other evidence of a structural neurological disease (like stroke).

This is because in functional weakness all the parts of the nervous system are there, they are just not working properly so that when you try to move your arm or leg it doesn’t do it as well as it should.

Your doctor may be able to find specific physical signs of functional weakness when you are examined and make the diagnosis in the same way as you would with a condition like migraine (which also does not have a ‘test’).

If you were a computer, it’s a bit like having a software problem rather than a hardware problem

Positive signs of functional weakness include the following, although none are 100% reliable and should not be used on their own:

• Collapsing weakness – this is a tendency for an arm or leg to ‘collapse’ when being tested. This may be interpreted by a doctor as ‘not trying’. In fact, patients with functional weakness typically find that the limb gets weaker the more they try

• Hoover’s sign – in this test, your affected leg may be weak when you try to push your foot down into the bed. However, when the doctor asks you to push up with your other leg the strength in your affected leg returns. Some patients with functional weakness use this sign as a form of physiotherapy to encourage normal movement in their affected leg (and to help demonstrate to themselves that the diagnosis is correct)

The video below shows me examining Lucy who had functional limb weakness affecting her right arm and leg. You can also see her talking about her facial spasm elsewhere on this website. Thank you Lucy for letting me share this video. You can also hear her talking about her symptoms on a BBC Radio 4 programme called ‘Inside Health’ in October 2012.

Hoover’s sign is a positive sign of functional limb weakness.

The video of Hoover’s sign shows that Lucy has weakness of her right leg. When she tries to keep it flat on the floor she can’t.

But when I ask her to lift up her normal left leg and focus on keeping that in the air then the weakness of the right leg temporarily goes away.

The explanation for this is that when Lucy is trying hard to move the right leg it doesn’t do what it’s told, there is a problem in the function of the brain and nervous system getting in the way. But when she is focusing on the left leg, automatic movements return showing that the weakness is not due to damage.

You might need to watch the clip a few times to get your head round it!

• Hip Abductor sign – This sign is positive when someone tries to push out with their hip, but is not able to do that as well as they can with the other side (hip abductor weakness). However, when they push out with their good side, strength is much better in the side that was originally weak. Have a look at the video below of Rachel who had functional limb weakness as part of FND

Hip abduction sign of functional leg weakness in FND

Patients with functional leg weakness sometimes drag their leg behind them as shown in these two pictures.

•A dragging kind of walk – Patients with functional leg weakness sometimes have a very characteristic way of walking which means that their affected leg “drags” along the ground. This is different to someone with a stroke or multiple sclerosis who swings their leg if they are able to stand up.

Patients with functional leg weakness sometimes drag their leg behind them as shown in these two pictures

•A difference between the examination of power on the bed and when walking – some people with functional weakness have relatively normal examination of strength in the legs on the bed but weak legs when walking. The reverse can also be true. This is not because they are not trying to walk, the variability is a key feature of the diagnosis.

Normal scans and tests help to make the diagnosis, but the diagnosis is usually made at the bedside on the basis of these positive signs by a neurologist when they first meet you

How does functional limb weakness happen?

Functional limb weakness is a complex problem. It arises for different reasons in different people. Often the symptoms are accompanied by feelings of frustration, worry and low mood but these are not the cause of the problem.

We recognise a number of different situations in which functional weakness can arise. Your symptom may fall in to one of these categories although none of them may be relevant to you:

1. After an injury / with pain—People seem particularly vulnerable to functional weakness after a physical injury or if they have a lot of pain (particularly severe neck or back pain). Sometimes functional weakness overlaps with another condition called Complex Regional Pain Syndrome. Click on the link to find out more.

2. An illness with a lot of fatigue or bed rest— weakness can develop slowly in people who are suffering from a lot of fatigue or exhaustion. In some patients too much rest can bring the symptoms on. There may be an overlap in this situation with Chronic Fatigue Syndrome. Click on the link to find out more.

3. Waking up from an anaesthetic after an operation or arising from sleep —this is not due to damage from the anaesthetic but may be something to do with the temporarily altered brain state when coming round. Similar things sometimes occur when you wake up normally.

4. After an episode of dissociation / panic attack– If your weakness came on suddenly it may have been associated with some other symptoms like lightheadedness and dissociation (a feeling that things around you were distant or disconnected). Dissociation is a bit like a trance and is described more in this website. Sometimes these episodes are very frightening, especially if they come ‘out of the blue’ and can lead to a panic attack. Once the panic attack is over it can leave behind the feeling that one half of the body is ‘not right’, perhaps heavy or tingly.

Sometimes symptoms come on after a functional/dissociative seizure (click here)

6. Triggered by a migraine. In some types of migraine there is an “aura” which means people get numbness, tingling or weakness down one side of their body. Especially if you have never had this before this can be frightening and trigger FND

5. No obvious precipitant – there may be no obvious precipitant, just as some people with migraine have them only when tired or stressed, whereas some have them for no reason at all.

Click on Treatment to find out more in general and find the specific page on the treatment of functional weakness

joe giudice weight loss diet pills in mexico weight loss for men gnc weight loss energy pills how to lose weight overnight top ten weight loss pills best birth control for weight loss acai berry cleanse diet pills lose weight water fasting keto diet average weight loss do chia seeds help you lose weight swimming weight loss success stories laxatives weight loss results effective weight loss pill dr now weight loss diet where can i buy black beauty diet pills weight loss progress pictures prescription pills for weight loss can kombucha help you lose weight atkins keto diet coffee on a keto diet how do i lose water weight dr oz on weight loss pills keto diet for pescatarians beans for keto diet top ranked weight loss pills original ace diet pills acai berry diet pills in stores way to lose weight fast without pills keto diet whole milk buy diet pills australia how much weight can you lose in a sauna information about diet pills indian keto diet plan pdf

anderson window sash replacement window 7 installation tutorial how much to replace a house window foggy rv window repair whole house window replacement window replacement washington how to install replacement basement windows replacement windows jackson chicago replacement windows storm window pane replacement replacement windows hawaii where can i buy a replacement window screen windows os replacement home window repair 15133 40 x 54 replacement window home window repair in palmdale ca top 5 window replacement companies home window replacement tampe window pane replacement calgary window replacement lewisville tx window awning installation vinyl replacement windows price window channel balance repair kit replacement windows with blinds between the glass power window repair puerto rico peachtree window parts replacement window screen repair dallas tx repair casement window sash cost to rescreen windows window replacement cost toronto house window replacement charlotte broken glass door repair replacement windows brighton window track repair cost

cbd oil affiliate cbd oil for foot neuropathy hemp seed oil vs cbd oil can you take cbd oil for migraine full spectrum cbd oil for sale near me cbd oil lincoln nebraska cbd oil daily dosage cbd oil and 2a hemp oil capsule benefits cbd oil and hemp oil the same thing how much to take of cbd oil for anxiety cbd oil indicta mendo cbd oil plus cbd oil green nanoemulsion cbd oil portland oregon hemp oil images how many mg of cbd oil gor 14 yr old cbd oil cotton candy purely cbd oil reviews cbd oil store knoxville tennessee cbd oil for scabies cannabis oil ohio how much cbd oil needed to treat anxiety howto take cbd oil cbd oil at wagreens hemp oil for benign tumors cbd oil turmeric horses taking cbd oil with perc 10 how old do u have to be to by cbd oil in kansas hemp oil treatment for prostate cancer approved for iowa cbd oil how is 1500 mg cbd oil measured make small batch cbd oil with glycerin erathbound cbd oil 900 mg

cialis 5 enhancement products penis enlargement machine how to have intercourse with erectile dysfunction best price on viagra foods to increase libido for men ed treatment drugs king size male enhancement pills viagra in cvs taking viagra with cialis free male enhancement samples no credit card testosterone low libido what helps erectile dysfunction vitamin max size male enhancement cream sexual supplements pills to help with erectile dysfunction how to increase sex time with medicine adderall and cialis libido plus pills enhancing supplement blue monster pill male enhancement pills harris teeter best price for rhino male enhancement pills male stimulant popping rock male enhancement pill ways to increase testosterone levels penis enlargement pills f v10 male enhancement pills penis growth pills amazon viagra patent expiration seth gamble penis pills gnc testosterone booster supplements fitwell testosterone pills male enhancement pills at gnc stores