Myoclonus

Classification according to ICD-10
G25.3	Myoclonus
ICD-10 online (WHO version 2019)

Myoclonia are rapid involuntary muscle twitching that often occurs as an accompanying symptom in a variety of neurological diseases. They are generated cortically (cerebral cortex), subcortically (other regions of the brain) or spinally (spinal cord). They are counted among the extrapyramidal hyperkinesias .

There are also myoclonus as natural phenomena without disease value, such as falling asleep .

Myoclonia are rhythmic or arrhythmic twitching of local muscle groups , multifocal or generalized. The exercise intensity varies. Extremity sections close to the trunk are often affected, as well as facial expressions and trunk muscles . If the myoclonus is intensified or activated by voluntary movement, one speaks of an action myoclonus. If they are triggered by external stimuli (touch, light stimuli , sounds), they are called reflex myoclonus.

causes

Myoclonia can have various causes.

epilepsy

Myoclonia can occur in the context of epilepsy , for example in the context of juvenile myoclonic epilepsy or in progressive myoclonic epilepsy . Epileptic myoclonus cannot be interrupted by external influences. Typical patterns for epilepsy can be seen in the EEG .

Other diseases

Myoclonus can also occur as a symptom in various non-epileptic diseases. In contrast to epileptic myoclonus, these myoclonus can be influenced by addressing them / touching them and the EEG does not show any epilepsy patterns.

• Syncope (approx. 90% of childhood syncope show myoclonus as a symptom)
• Simple tics
• In the context of neurodegenerative diseases such as gluten ataxia
• Essential myoclonus
• Shuddering attacks
• Benign Infant Sleep Myoclonus
• Benign early childhood myoclonus

In addition, (cortical) myoclonus occur in the following diseases:

• Creutzfeldt-Jakob disease ,
• metabolic encephalopathy ( hyponatremia , hypokalaemia ),
• Viral encephalitis ,
• Toxic encephalitis ( heavy metal , alcohol, or drug intoxication )
• Organoacidopathies
• Acute posthypoxic myoclonus syndrome
• Chronic posthypoxic myoclonus syndrome (synonym: Lance-Adams syndrome)
• Anticholinergic Syndrome
• Schwartz-Bartter Syndrome
• Acute intermittent porphyria
• Beta Propeller Protein Associated Neurodegeneration

Myoclonia can also be triggered by centrally acting analgesics and occur particularly with high-dose opioids that are administered in long-term therapy . They can also be signs of serotonin syndrome .

See also

• twitch
• Clone
• Fasciculation

Individual evidence

1. ↑ Medical Tribune, 21. Consilium live 4/2009  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 323 kB).  
2. ^ Arznei-telegram 3/2005

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !