Myoclonus

Myoclonus is a term that describes a group of involuntary muscle actions (dyskinesias) that may happen in two ways:

• Positive myoclonus: Sudden muscle twitching.
• Negative myoclonus: When your muscles suddenly relax even though you’re not trying to relax them.

Myoclonus symptoms

Myoclonus isn’t exactly a standalone condition that can be diagnosed. Think of it more like a symptom that happens in various ways to people of all ages. Myoclonus episodes, where you suddenly have twitching muscles or relaxed muscles, can vary:

• They may be mild or severe.
• The movements may follow a steady rhythm or be random.
• It might happen frequently or every now and then.
• The movements may be slow or fast.
• It could happen with single movements or multiple movements.

Myoclonus might affect just one part of your body or multiple parts.

Myoclonus & other conditions

Muscle twitching or muscle relaxing events may occur in different situations. Sometimes myoclonus events happen to individuals dealing with conditions such as epilepsy disorders, multiple sclerosis (MS), Alzheimer’s disease or Parkinson’s disease. Additionally, myoclonus, characterized by twitching muscles, may happen due to underlying conditions such as:

• Brain tumors
• Exposure to certain chemicals or medications
• Head or spinal cord injuries
• Infections
• Kidney or liver failure
• Lack of oxygen to the brain (hypoxia)
• Metabolic disorders
• Stroke

It's worth noting that myoclonus may occur in people with no other underlying conditions or diseases.

Myoclonus causes

While we don’t know how to stop muscle twitching or what causes myoclonus, researchers have identified potential starting points in the brain.

The cerebral cortex, a part of the brain, is the most common origin of myoclonus, closely followed by the brain stem. Current research suggests that muscle twitching causes may be linked to:

• Overexcitability of parts of the brain responsible for movement
• Imbalances in neurotransmitters

Types of myoclonus

There are different types of myoclonus based on what appears to trigger these incidents. Whether it's linked to another disease or condition, or connected to nerve activity in specific areas like the brain, spinal cord or peripheral nerves, here are some common types:

• Action myoclonus: This type is triggered by voluntary movement or the intention to move.
• Cortical reflex myoclonus: Linked to nerve activity in the cerebral cortex (a part of the brain).
• Epileptic myoclonus: Connected to living with epilepsy disorders.
• Peripheral myoclonus: Associated with nerve activity in a peripheral nerve (outside the brain and spinal cord).
• Reticular reflex myoclonus: Tied to activity in the brain stem.
• Sleep myoclonus: It occurs during sleep or as you're falling asleep. It’s also known as restless leg syndrome.
• Spinal myoclonus: Related to nerve activity in the spinal cord.
• Stimulus-sensitive myoclonus: This type is triggered by external factors like light, noise, or movement.

Identifying the specific type of muscle twitching helps guide your doctor in recommending effective myoclonus treatments tailored to your situation.

Diagnosis of myoclonus

After a physical examination and discussing your potential myoclonus symptoms and medical history, your doctor may recommend various tests to confirm any diagnosis. These tests help provide a comprehensive understanding of your condition:

• Blood and urine lab tests: These tests aim to identify possible causes and exclude conditions that share similar symptoms.
• Electromyography (EMG): This test measures the electrical activity in your muscles, offering insights into their functioning.
• Electroencephalography (EEG): During myoclonus events and periods without them, this test records the electrical activity in your brain, aiding in the diagnostic process.
• MRI (Magnetic resonance imaging): This imaging technique captures detailed pictures of the brain, spinal cord, nerves, muscles, or other tissues, helping to visualize any abnormalities.

Myoclonus treatment

The approach to treating myoclonus events is highly personalized, taking into account your overall health and the specific details gathered about your twitching muscle episodes.

Initially, the focus will be on addressing any underlying conditions. However, in many cases your treatment will focus on reducing the frequency of your muscle twitching episodes or making them less intense. Myoclonus treatments often involve medications, including:

• Clonazepam: This tranquilizer is commonly prescribed for certain types of myoclonus.
• Epilepsy medications: Such as barbiturates, phenytoin, levetiracetam, valproate, or primidone.
• Combined medications: Sometimes, a combination of medications may prove more effective than individual ones.
• Hormonal therapy: This approach may enhance treatment when used in conjunction with other medications.
• Botox injections: These injections are utilized for myoclonus episodes affecting facial muscles or the soft palate in the mouth.

Your doctor will carefully tailor your treatment plan to best address your specific needs and enhance your quality of life.