Myoclonus

Overview and Facts about Myoclonus

Myoclonus is a neurology disorder associated with quick, involuntary muscle movements. These movements normally don’t present a problem and can occur in healthy people or those with certain movement disorders like epilepsy.

Some of the most common forms of myoclonus are hiccups or sudden jerks before falling asleep. In rare cases, the movements can become debilitating.

There are several types of myoclonus. The most common include:

• Action myoclonus: This occurs with voluntary movements and often develops after a brain injury
• Cortical reflex myoclonus: This primarily occurs in a few muscles in a specific part of the body and is currently considered a form of epilepsy
• Essential myoclonus: This occurs without worsening and with no apparent brain or nerve abnormalities. It is sometimes associated with essential tremor or myoclonus dystonia
• Palatal myoclonus: This is a rapid, rhythmic contraction on either or both sides of the mouth’s soft palate
• Progressive myoclonus epilepsy (PME): This is a group of rare neurological diseases that worsen with time and can become fatal. It can result from a genetic disorder, cerebral storage disease, or system degeneration
• Reticular reflex myoclonus: This is a form of epilepsy that causes whole body jerks but may be limited to the legs
• Stimulus-sensitive myoclonus: This occurs when triggered by external stimuli, including movements, noise, or light
• Sleep myoclonus: This occurs during the initial stages of sleep

Signs and Symptoms of Myoclonus

The most common symptoms of myoclonus are involuntary jerks or spasms. These movements can occur rarely or frequently and be mild or intense, although these movements are often described as being brief, sudden, shocking, and intense.

These jerks can become so strong that they interfere with walking, talking, or eating, although this extremity is uncommon.

Causes and Risk Factors of Myoclonus

Myoclonus can result from different types of brain and nerve conditions, like epilepsy or brain trauma. Other diseases that can lead to myoclonus include:

• Alzheimer’s disease
• Autoimmune inflammatory disorders
• Brain tumors
• Corticobasal degeneration
• Creutzfeldt–Jakob disease
• Drug or chemical poisoning
• Frontotemporal dementia
• Huntington’s disease
• Infections
• Kidney or liver failure
• Lewy body dementia
• Lipid storage disease
• Medication reaction
• Metabolic diseases
• Multiple system atrophy
• Parkinson’s disease
• Prolonged oxygen deprivation
• Spinal cord injury
• Strokes

Certain types of epilepsy or other movement disorders can increase a patient’s risk for developing myoclonus. The other primary risk factor is having a family history of the disease.

Test and Diagnosis of Myoclonus

A neurology specialist diagnoses myoclonus after reviewing a patient’s medical history and systems and completing a physical examination. To confirm the condition, the doctor may request certain testing, including:

• Electroencephalography (EEG)
• Electromyography (EMG)
• Magnetic resonance imaging (MRI)
• Laboratory testing for underlying conditions

Treatment and Care for Tremors

Treatment of myoclonus depends on the cause. In cases where myoclonus is a symptom of another condition, the treatment focuses on the underlying issue.

When the cause of the movement disorder is unknown, the doctor focuses on reducing the body spasms and jerks. The doctor may recommend:

• Medications, including tranquilizers, anticonvulsants, or valproic acid
• Botox therapy
• Surgery
• Deep brain stimulation (DBS)