Myoclonus

When your muscle or muscles produce shock-like contractions, then the condition is termed as myoclonus. Hiccups are also a form of myoclonus; we may also feel sudden jerks when sleep starts or just before we sleep. These forms of myoclonus are not bothersome; they occur in healthy people though.
Myoclonus is considered as a symptom of other condition and not a diagnosis of a disease. Myoclonus may occur because of a neurological disorder such as epilepsy, any metabolic disorders or adverse drug reactions.
The primary goals of treatment include treating the underlying causes of myoclonus; this helps reduce the symptoms. If the cause is unknown, then the treatment focuses on alleviating the effects of myoclonus and in improving the quality of life.

Symptoms

You may experience jerks, shakes or spasms that are sudden, brief or involuntary in onset. These shocks like contractions vary in their intensity and frequency. The contractions are typically localized; these symptoms may interfere with the day-to-day activities such as eating, speaking, or walking.

If the symptoms associated with myoclonus are frequent and persistent, then you must call your doctor for further evaluation and diagnosis followed by appropriate treatment.

Causes

Myoclonus may occur when abnormal electrical impulse generated by the central nervous system affects a muscle or group of muscles. In most of the cases, Myoclonus may occur as a result of underlying conditions that include:

  • Brain or spinal cord injuries
  • Epilepsy
  • Brain tumors
  • Kidney failure
  • Liver damage
  • Drug or chemical poisoning
  • Hypoxia

Type of myoclonus

  • Myoclonus is of different types which are differentiated based on the underlying cause and include the following: Physiologic myoclonus occurs during sleep phases; these are termed as hypnic myoclonus, they may be focal, multifocal, segmental, or generalized.

  • Pathologic myoclonus may result from various disorders and drugs side effects. The common causes would include hypoxia, drug toxicity, and metabolic disturbances, degenerative disorders and some dementias.

  • Brain tumors

  • Essential myoclonus usually occurs without any symptoms and any related underlying cause. The cause may be hereditary.

  • Epileptic myoclonus occurs as a part of an epileptic disorder.

  • Symptomatic myoclonus occurs because of the underlying medical condition, which may include head or spinal cord injury, infection, liver failure, drug poisoning.

 

Diagnosis

Your doctor will initially review your medical history and checks for symptoms. A physical examination is also performed. Your doctor may recommend relevant tests to determine the cause of myoclonus and rule out other potential causes.

The tests include:

Electroencephalography (EEG)

In this procedure, doctor attaches small electrodes to your scalp; this helps record the electrical activity of your brain and helps in determining the origin of myoclonus.

Electromyography (EMG)

In this procedure, doctor puts EMG surface electrodes on the muscles which are involved in jerking. This procedure measures the electrical discharges produced in the muscles and helps in establishing the pattern of myoclonus.

Magnetic resonance imaging (MRI)

Your doctor suggests MRI scan for detecting the involved structural problems or tumors inside the brain or spinal cord, which can be the cause for myoclonus.

Laboratory tests

Your doctor would order for genetic testing, blood or urine analysis to identify the possible cause of myoclonus.

Treatment

The treatment for myoclonus is the most effective one if the underlying cause can be found; it may include a drug or a toxin. The treatment of myoclonus focuses on reducing the symptoms.

Your doctor may prescribe certain medications which include tranquilizers and anticonvulsants. These drugs are potential for causing side effects too.

Your doctor may prescribe certain medications which include tranquilizers and anticonvulsants. These drugs are potential for causing side effects too.

Your doctor may prescribe onabotulinumtoxinA (Botox) injections for treating different types of myoclonus. This toxin blocks the chemicals that are essential for muscle contractions.

Surgery

If the cause of myoclonus is identified as a tumor or lesion in the brain or spinal cord, then your doctor would recommend for surgery.