Definition

Muscle twitching, also known as myoclonus, is a condition where muscles twitch rapidly and involuntarily. This can be caused by sudden muscle contractions known as "positive myoclonus" or sudden loss of muscle tension called "negative myoclonus." While it can occur during hiccups or when falling asleep in normal individuals, it can also be a symptom of certain conditions.

Causes

Twitching can be caused by various factors, ranging from every day, non-severe causes to serious ones. Common, everyday causes of twitching include:

• Physical activity, which increases the amount of lactic acid in muscles, causing twitching, especially in the arms, legs, and back.
• Stress and anxiety, which cause muscle twitching known as "tics" and can affect any muscle in the body.
• Stimulants like caffeine can cause muscle twitching.
• Nutritional deficiencies, such as lack of vitamin D, vitamin B, and calcium, can cause muscle twitching, especially in the eyelids, calves, and hands.
• Dehydration can cause twitching, particularly in large muscles like those in the arms, legs, and chest.
• Nicotine from cigarettes and other tobacco products can cause muscle twitching, especially in the legs.
• Irritation of the eyelids or eye surface can cause muscles around the eyes to twitch.
• Side effects of certain medications, such as steroids and birth control pills, can include muscle twitching in the hands, arms, or legs.
• Electrolyte imbalances, such as those involving sodium and potassium, can cause muscle twitching. This is usually caused by excessive sweating, high-intensity exercise, or fluid loss due to vomiting or diarrhea.
• Lack of sleep can cause imbalances in brain chemicals (neurotransmitters), leading to twitching.

Serious causes of muscle twitching include:

• Muscular dystrophy: A genetic condition that damages and weakens muscles over time, causing twitching in the face, neck, shoulders, and waist.
• Amyotrophic Lateral Sclerosis (ALS): A disease that causes nerve cells to die, leading to muscle twitching in various parts of the body, usually starting in the arms and legs.
• Muscle atrophy due to spinal cord damage: This condition causes nerve damage in the spinal cord that controls muscles in the body.
• Chronic kidney failure: This disorder can cause fluid and electrolyte imbalances in the body, leading to muscle twitching.
• Myopathy: This condition affects the function of nerves and muscles, causing cramps, stiffness, and muscle twitching.
• Serotonin syndrome: This condition occurs when serotonin levels in the body are too high, often due to certain medications.
• Neuropathy: This condition involves nerve damage, causing numbness, pain, and muscle twitching, especially in the hands and feet.

Besides the above conditions, muscle twitching can be associated with epilepsy, a condition where brain electrical waves are disrupted without a trigger, causing recurrent seizures, or it can be unrelated to any condition (known as essential myoclonus).

Risk factor

Muscle twitching caused by serious conditions is rare, with an incidence of about 9 cases per 100,000 people. This incidence increases in individuals over 50 years old. About a quarter of cases are temporary and drug-dependent, while around 8% are not serious conditions. The most common cause of muscle twitching is related to medical conditions or certain medications (72%), followed by twitching due to epilepsy (17%), while essential myoclonus occurs in only 11% of all myoclonus cases. This means that muscle twitching is more often a symptom of other medical conditions or a side effect of medications.

Symptoms

As the name suggests, "twitching" is characterized by sudden muscle movements in an area of the body. These muscle movements can include jerking, shaking, or stiffness, which is sudden, brief, involuntary, like an electric shock, varying in intensity and frequency, and occurring in one part of the body or throughout the body. These muscle movements can sometimes be severe enough to cause eating, speaking, or walking disturbances.

Diagnosis

Diagnosing the cause of twitching can start with questions about the onset, duration, affected body part, frequency of twitching, family history, medical history, medication history, and the rhythm of the twitching. Additionally, questions can explore symptoms associated with muscle twitching.

A direct examination can be conducted, primarily to look for other symptoms that may indicate the cause of muscle twitching. This examination may include a thorough nerve examination. You may be asked to feel touch or temperature, determine body movement direction, walk, move body muscles, and perform some movements to check coordination between body parts. Reflex tests on various specific muscles can also be conducted.

Furthermore, tests can be involved to assess nerve function, such as higher function or cognitive tests, electromyography, and electroencephalography. Electromyography (EMG) aims to examine the electrical conduction from nerves to muscles to move, while electroencephalography (EEG) aims to check brain electrical waves.

Imaging tests can also be conducted, such as magnetic resonance imaging (MRI) to look for abnormalities in brain and spinal cord tissues. Laboratory tests can be performed to look for other possible causes of muscle twitching, such as complete blood tests, blood sugar levels, autoantibodies (immune system attacking self-cells), kidney function, liver function, and medication levels in the body.

Management

The treatment for muscle twitching depends on its cause. If muscle twitching is caused by common, everyday factors, no specific treatment is needed. However, if muscle twitching is related to other medical conditions, treatment can be directed at those conditions. If the cause of muscle twitching is medication or poisoning, stopping the medication can improve the condition. If the cause is a serious condition that may not be curable, sedatives and anticonvulsants can be given to eliminate muscle twitching.

Severe muscle twitching can cause mood instability, so mental health support may be needed in certain conditions.

Complications

Muscle twitching can cause significant disturbances in daily activities and even lead to depression. This happens because muscle twitching occurs at rest or interferes with activities requiring precise movements.

Prevention

Muscle twitching cannot always be prevented, but some actions can reduce the risk:

• Eat a balanced diet, including vegetables and fruits, carbohydrates, fiber, and protein, especially low-fat protein like chicken and tofu.
• Get enough sleep (7-9 hours per day) to allow nerves to rest.
• Manage stress with relaxation techniques like meditation, yoga, Tai Chi, and regular physical activity at least 3 times a week.
• Limit caffeine intake to reduce the risk of muscle twitching.
• Quit smoking to lower nicotine levels in the body.
• Consult a doctor to change medications if you are regularly taking ones that may cause muscle twitching.

When to see a doctor?

See a doctor immediately if you or someone near you experience frequent muscle twitching. Other warning signs include muscle twitching accompanied by muscle weakness and atrophy. Frequent muscle twitching or those with warning signs can indicate a more severe or life-threatening condition.

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