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Benign Fasciculation Syndrome (BFS)

Published on Feb 28, 2019 and last reviewed on Jun 27, 2020   -  5 min read


Persistent muscle twitches or tingling sensations or numbness in one or more muscles of the body is called benign fasciculation syndrome (BFS).

Benign Fasciculation Syndrome (BFS)

What Is Fasciculation?

Fasciculation or muscle twitch is the involuntary contraction of small muscles in the body. Most people experience twitching in their eyelids. Muscle twitches are not painful and are usually not a cause for concern. But, it can be a symptom of some serious health condition like amyotrophic lateral sclerosis (ALS) or otherwise known as Lou Gehrig’s disease. So, it is always better to get persistent muscle twitches evaluated by a medical professional.

What Is Benign Fasciculation Syndrome?

Persistent muscle twitches or tingling sensations or numbness in one or more muscles of the body is called benign fasciculation syndrome (BFS). Usually, the spasms seen in BFS do not cause sudden jerking or full contraction of the muscles, but they are strong enough for the person to feel them.

Muscle twitches occur when the motor units, which are the muscles and nerve fibers that work together to contract a muscle, get stimulated on their own. This causes involuntary, unexpected, and sudden fasciculations that are out of the brain’s control. BFS either lasts for a long period of time or keeps coming back regularly.

What Are the Symptoms of Benign Fasciculation Syndrome?

The primary symptom of BFS is muscle twitching, numbness, or tingling sensation. People with this condition may have twitches in their eye, tongue, arms, thumb, feet, thighs, and calves. Some people also experience muscle cramps. The most common places where people experience twitching is in the calves and thighs. Fasciculations are more noticeable when the person is at rest.

The other common signs and symptoms include:

In some cases, these fasciculations can get transferred from one part to another part of the body. Meaning, if you have tremors in a leg muscle, it can jump to the abdomen in a few seconds.

What Causes Benign Fasciculation Syndrome?

The exact cause of BFS is still unknown, as it is a very rare condition. It was thought to be caused due to overactive nerves. Some of the conditions that have been associated with fasciculations are:

Some medicines also cause muscle twitching, which subsides on stopping the medicine. The medicines that cause fasciculations are:

What Are the Other Conditions That Cause Muscle Twitches?

Some of the other health conditions that cause fasciculations are:

How to Differentiate BFS From ALS?

BFS is commonly mistaken for ALS, as they share many similar symptoms. The symptom that is commonly used to tell them apart is muscle wasting. That is, the muscles in ALS get atrophied and shrink over time. This makes a person suffering from ALS progressively weaker. But this symptom is not commonly seen in BFS.

Fasciculations are common in both conditions, but in BFS, fasciculations are more widespread. Muscle twitching is commonly experienced at rest and stops once the person uses the muscle.

In ALS, fasciculations start in a particular place and then often spread to the surrounding areas. Both these conditions are different and are not connected.

How Is Benign Fasciculation Syndrome Diagnosed?

As mentioned earlier, fasciculations can be a symptom of many other health conditions, so it is crucial to diagnose the cause. Muscle twitches are evaluated primarily with electromyography (EMG). Here, the muscle response is recorded after stimulating a nerve with a small amount of electricity.

To rule out all other causes of twitching, the doctor might also perform the following tests:

How Is Benign Fasciculation Syndrome Treated?

As of now, there is no treatment available to reduce benign fasciculation syndrome. They usually resolve on their own once the trigger is identified and eliminated. Some doctors prescribe medicines that decrease the nerve excitability, like:

Stretching and massage can help with muscle cramps. If no other treatment is effective, then Prednisone, an immunosuppressive drug, is prescribed.

If BFS is believed to be caused due to stress and anxiety, it is found that the following remedies might help:

  1. Exercise - Exercise is shown to improve mood and reduce stress.

  2. Limiting the intake of alcohol, drugs, and caffeine, as these can make stress worse.

  3. Consuming a healthy and balanced diet, which includes a lot of fruits and vegetables, helps the immune system to work properly even during stress.

  4. Organize and think about your work and the things you need to do before you begin.

  5. Take time off your busy schedule for your hobbies or things you like to do.

  6. Meditation, yoga, and other breathing and relaxation techniques can also help.

  7. Talk to your friend, family member, or anyone you trust about the thing that is bothering you.

BFS does not cause long-term physical damage, and there have been cases that reported spontaneous remission. Most patients get better when the underlying anxiety is addressed and treated. If your muscle twitches are getting worse with time or are causing pain and discomfort, it is best you consult a doctor online. The doctor will suggest treatment options that might be best suited for you.


Frequently Asked Questions


Is benign fasciculation syndrome serious?

Benign fasciculation syndrome results in harmless muscle twitches in the eye, arms, feet, thighs, and calves. This syndrome is not associated with any serious neuromuscular problem. But, chronic muscle twitches can result in anxiety, especially if it affects the hands.


Does benign fasciculation syndrome go away on its own?

There are known cases where muscle twitches get better on their own. If you can identify and control triggers, the symptoms are lessened to a great extent.


When to worry about muscle twitching?

Too much stress, dehydration, certain medications, lack of sleep, too much caffeine, etc., are the most common causes of muscle twitching. But sometimes, they can be due to neuromuscular disorder like ALS (amyotrophic lateral sclerosis). So if your muscle twitches do not get better in a week, or the muscles twitch even at rest, then it is best to consult a doctor.


Can anxiety cause benign fasciculation syndrome?

Yes, it can. Anxiety and stress can result in the release of neurotransmitters, which can result in muscle twitching. Anxiety might also make you hyperventilate, which can also result in twitching.


Does benign fasciculation syndrome get worse with time?

Benign fasciculation does not usually get worse with time. Most people see improvement in symptoms with treatment. Only in some rare cases, the symptoms were seen to get worse with time.


Is it normal to have muscle twitches every day?

Muscle twitches are quite common, and they usually go unnoticed by most. But if the muscle twitches are severe, do not get better with rest, and occur every day, then it is best to consult a doctor.


Is BFS an autoimmune disorder?

No, BFS is not an autoimmune disorder. It is caused by the overactivity of the nerves that are associated with the muscles that twitch. There are various factors that increase the risk of this overactivity.


Is benign fasciculation syndrome permanent?

BFS is not a progressive condition; neither does it affect the person permanently. As mentioned above, most people with BFS get better.


What other diseases cause fasciculations?

Some of the serious diseases that can cause fasciculations are:
- Radiculopathy (a pinched spinal nerve).
- ALS.
- Isaac’s syndrome.
- Lupus.
- Multiple sclerosis.

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Last reviewed at:
27 Jun 2020  -  5 min read




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