Myoclonus
What is Myoclonus?
Overview
Myoclonus, which refers to an involuntary lightning-fast quick jerk, has probably been experienced by all of us at one point or another, manifesting as the jerking of legs or body upon falling asleep.
This is a benign condition (known as hypnic jerks) and is no cause for alarm. However, at times myoclonus may be more pronounced, present at all times of day, becoming disruptive.
When myoclonus occurs while a limb is being held up it can look like a brief loss of tone, known as negative myoclonus. This can result in dropping things or even legs buckling and falls in rare cases.
When myoclonus is more sustained or pronounced, an evaluation should be conducted to elucidate the underlying cause.
Who is Affected?
Myoclonus can affect people of any age, but the underlying cause often determines who is most at risk.
- Essential myoclonus often appears in otherwise healthy individuals and may run in families.
- Metabolic or medication-induced myoclonus can occur in people with liver or kidney problems or those taking certain medications.
- Epileptic myoclonus is seen in individuals with seizure disorders.
- Neurodegenerative-related myoclonus is more common in older adults with conditions such as dementia or movement disorders.
Myoclonus Symptoms & Causes
Symptoms
The main symptom of myoclonus is sudden, brief, involuntary muscle jerks, which may:
- Affect one area (focal myoclonus) or multiple parts of the body (generalized myoclonus).
- Occur at rest or during movement.
- Range from mild twitches to forceful jerks that disrupt posture or activities.
- Be triggered by movement, stress, fatigue, or sensory stimuli.
Causes
There is a long list of causes of myoclonus, including medications, kidney or liver failure, epilepsy, degenerative conditions such as dementia, and genetic causes.
Sometimes the cause is not identified, and is known as essential myoclonus. The term “essential” means that the essence of the condition is myoclonus; it is another way of saying the myoclonus “is what it is”. The exam is otherwise normal, and the myoclonus tends to remain stable over the years. Essential myoclonus can be associated in families with essential tremor (ET) or a type of dystonia called myoclonus dystonia.
When to See a Doctor
Prompt evaluation can help identify treatable causes and prevent complications. Seek medical evaluation if you experience:
- Frequent or worsening muscle jerks that interfere with daily life.
- Unexplained movements after starting a new medication.
- Associated symptoms like confusion, weakness, or seizures.
- Falls, leg buckling, or difficulty holding objects due to myoclonus.
Myoclonus Diagnosis
Diagnosis begins with a detailed medical history and neurological examination. Additional testing may include:
Blood & Metabolic Tests
To check for underlying organ or metabolic problems.
EEG (Electroencephalogram)
If seizures are suspected.
MRI or CT Scans
To evaluate brain structure.
Genetic Testing
When hereditary conditions are considered.
Myoclonus Treatment & Outcomes
Treatment Options
Treatment can include sedatives such as clonazepam and anti-epileptic medications (even though the myoclonus may not be caused by epilepsy) such as levetiracetam (Keppra), valproic acid (Depakote), phenytoin (Dilantin) or primidone.
Patient Outcomes
With the right treatment plan, many patients experience substantial improvement in symptoms, leading to better mobility, safety, and quality of life. In cases where the cause is treatable, myoclonus may improve or resolve entirely. Essential or degenerative-related myoclonus can often be managed effectively with long-term therapy.
Managing Myoclonus
Managing myoclonus may involve long-term medication use, lifestyle adjustments to avoid triggers, and physical or occupational therapy for patients with balance or functional difficulties. Ongoing follow-up with a neurologist ensures that treatment remains effective and any changes in symptoms are addressed promptly.
Meet our Expert Specialists & Surgeons
Experience Compassionate, Expert Care
At the Pacific Neuroscience Institute, our movement disorders specialists are experienced in diagnosing and treating all forms of myoclonus. We combine advanced diagnostic tools, including EEG and neuroimaging, with personalized treatment strategies to reduce symptoms and improve quality of life.
Our multidisciplinary approach integrates neurology, neurorehabilitation, and supportive care, ensuring each patient receives comprehensive, compassionate treatment tailored to their needs.
Learn More About Myoclonus
Myoclonic seizures may be triggered by flashing lights, sudden noises, fatigue, or certain medications, but triggers vary by individual.
Treatment often involves medications such as clonazepam or anti-epileptic drugs, along with addressing any underlying causes.
While anxiety itself doesn’t directly cause myoclonus, stress and anxiety can worsen symptoms in people predisposed to muscle jerks.
Causes range from medications and metabolic problems to neurological disorders or genetic syndromes. Sometimes no cause is found (essential myoclonus).
Certain types of myoclonus may be triggered by sudden movement, sensory stimulation, fatigue, or emotional stress.
In most cases, myoclonus is benign, but when frequent or associated with underlying neurological conditions, it can impact safety and quality of life and requires medical evaluation.
Resources
Get Expert Care from Leading Specialists
If you or a loved one is experiencing frequent or disruptive myoclonus, the movement disorders team at Pacific Neuroscience Institute can help. Our specialists provide thorough evaluations, personalized treatment plans, and access to advanced therapies to help reduce symptoms and improve quality of life.
Written and reviewed by:
The Pacific Neuroscience medical and editorial team
We are a highly specialized team of medical professionals with extensive neurological and cranial disorder knowledge, expertise and writing experience.
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