CausesBy Mayo Clinic staff
Myoclonus may be caused by a variety of underlying problems. Doctors often separate the types of myoclonus based on their causes, which helps determine treatment. Types of myoclonus include the following categories.
This type of myoclonus occurs in normal, healthy people and rarely needs treatment. Examples include:
- Sleep starts
- Shakes or spasms due to anxiety or exercise
- Infant muscle twitching during sleep or after a feeding
Essential myoclonus occurs on its own, usually without other symptoms and without being related to any underlying illness. The cause of essential myoclonus is often unexplained (idiopathic) or, in some cases, hereditary.
This type of myoclonus occurs as part of an epileptic disorder. Muscle jerks may be the only sign or one of many.
Symptomatic (secondary) myoclonus
This is a common form of myoclonus. Muscle jerks occur as a result of an underlying medical condition, including:
- Head or spinal cord injury
- Kidney or liver failure
- Lipid storage disease
- Chemical or drug poisoning
- Prolonged oxygen deprivation
- Medication reaction
- Autoimmune inflammatory conditions
- Metabolic disorders
Nervous conditions that result in secondary myoclonus include:
- Brain tumor
- Huntington's disease
- Creutzfeldt-Jakob disease
- Alzheimer's disease
- Parkinson's disease and Lewy body dementia
- Corticobasal degeneration
- Frontotemporal dementia
- Multiple system atrophy
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- Neurological diagnostic tests and procedures. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/misc/diagnostic_tests.htm. Accessed Sept. 27, 2012.
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