Fasciculations (Muscle Twitching) and ALS

There are numerous different symptoms that are associated with a disease such as amyotrophic lateral sclerosis (ALS). Many of these symptoms are associated with other medical conditions, which can result in a misdiagnosis or a delay in an accurate diagnosis being achieved.

For example, weakness in one part of the body can initially be associated with lack of exercise, an illness such as a viral infection, or something much more serious.

One such symptom is muscle twitching, which is not only associated with ALS but also muscular dystrophy and spinal cord damage. It’s also something that can happen quite benignly and naturally and is not generally something to worry about when occurring in isolation.

Here we take closer look at fasciculations in relation to ALS and what can cause them to occur. We also examine what other causes of muscle twitching there might be and why you shouldn’t automatically assume you have a major health problem if you experience muscle twitching.

What are Fasciculations?

The technical name for muscle twitching is fasciculation and, whilst it can be seen as an initial sign of a condition such as ALS, it is experienced by many people and most often it is caused by nothing serious.

We all experience muscle twitching at some time or another. It might happen because we have had too much caffeine or there’s a mechanical issue like a trapped nerve. It can also occur, for instance, after a period of strenuous exercise.

Fasciculations usually happen out of the blue and disappear just as quickly. If muscle twitching persists for a longer period, however, it may point to an underlying health problem.

A doctor will not diagnose a condition like ALS through fasciculations alone and a number of tests need to be carried out and other symptoms taken into consideration, including the gradual weakening of muscles.  

What Causes Fasciculations to Occur?

There are several reasons why fasciculations occur and the most common is a disruption to the nerve impulse that feeds into a muscle. Our nerves have an important component called the axon, which is close to the muscle and this has the ability to fire off signals that gets the tissue contracting or relaxing.

Most of the time, the brain sends signals triggering a release of acetylcholine that moves from the axon to the muscle, thus causing a response. This process also happens involuntarily which means that we have no control over the action.  

In ALS, both upper and lower motor neurons in the body are affected. The disease progresses by causing damage to these nerves to the point where they cease to work properly, degenerate and eventually die. This damage causes an interruption in nerve impulses and that can lead to the occurrence of fasciculations in various parts of the body.

For instance, an individual with ALS might first notice a persistent shoulder twitch or muscle twitching in their face or legs. Whilst not painful, it can be so prevalent that it causes sleep disruption. 

There is some evidence to suggest that the firing rate and nature of fasciculations in respect to ALS are different compared to more benign causes and this might be a way to help diagnose the condition early in the future.

If muscle twitching does occur over a longer period of time, it may well resolve in a few weeks or months. It doesn’t mean that someone has ALS or another neurodegenerative disease. Often it can be the result of a trapped nerve that is causing the axon to fire off.

Other Causes of Fasciculations

There are other reasons why fasciculations happen. One example is a condition called benign fasciculation syndrome (BFS) which sometimes occurs as a response to a viral infection.

BFS is fairly rare and has a range of other causes apart from infection, including following the use of medications (especially allergy drugs). If you are taking medication and have started experiencing muscle twitching, stopping for a short period may see the problem resolve – but of course, professional medical advice should be sought before deciding to come off any prescribed medicine.

Muscle twitching can also be caused by trauma following an injury and can even occur as a result of high stress levels being experienced. There is some evidence to suggest that lack of minerals, such as calcium and magnesium are likely to increase the likelihood of fasciculations occurring.

Other factors that may be involved in ordinary muscle twitching include excess alcohol consumption, too much caffeine, bouts of strenuous exercise, and smoking. According to the research, around 70% of people will experience a benign fasciculation at some point in their life.