This type of epilepsy can present a brief period of shock-like jerks of the muscles that usually doesn’t last longer than a few seconds. The normal individuals can also experience the myoclonus as a sudden jerky movement when falling asleep. This can occur as one or several jerky movements in a short period of time. This can develop in a number of epilepsy syndromes presenting different characteristics such as the juvenile myoclonic epilepsy or the progressive myoclonic epilepsy. This typically presents abnormal movements on both the sides of the body at the same time. Individuals experiencing the myoclonic seizures can usually continue their activity during and after the seizure without affecting their ability to think. Hence, first aid is usually not required. Though this can usually begin in childhood, it can affect people of all ages. The diagnosis is possible by the evaluation of the affected individual’s medical history and with an EEG test. There are several treatments available to prevent the onset of myoclonic seizures which are quite effective.
Juvenile myoclonic epilepsy (JME)
This is one of the most common types of seizures to affect the mid-late childhood. This presents the absence seizures, myoclonic seizures and generalized tonic-clonic seizures. The initial onset of absence seizures can occur anywhere between the age of 5 and 16 followed by myoclonic jerks after several years and the generalized tonic-clonic seizures a few months later. It is estimated that around 20% of the cases present myoclonic jerks on the single side of the body. The myoclonic epilepsy is characterized as myoclonic jerks that can occur after sleep and typically appear as irregular movements of both the arms which in some cases are restricted to the fingers only. Some of the causes of this include the sleep deprivation and fatigue which appears to be common triggering factors. Additional triggers can include mental stress, overexcitement or frustration. JME can also be triggered by flickering lights, TV and video games. This appears to be a genetically determined syndrome where around 50 – 60% of the affected cases report seizures in the close family member. Treatment includes preventing the triggering causes such as sleep deprivation along with the anti-epileptic medications. The seizure appears to improve among these cases after the fourth decade and is usually well controlled with medications. This usually requires a lifelong treatment and the withdrawal can result in the relapse of the seizures.
Progressive myoclonus epilepsy (PME)
This condition involves the central nervous system presenting muscle contractions (myoclonus) and seizures (epilepsy). This is a rare group of disorders that features a combination of myoclonic and tonic-clonic seizures. This disorder includes a group of various syndromes such as lafora disease, mitochondrial encephalopathies and severe myoclonic epilepsy of infancy (dravet syndrome). Additional symptoms may also include the lack of motor coordination, impaired mental function affecting memory, depression and the bladder abnormality. Depending on the type of PME, the cases may also present gastrointestinal conditions, hearing impairment and vision problems. The rate of progression of PME is based on the underlying disease. The treatment is only successful for a few months or years and usually requires more seizure medication which may become ineffective. Consequently, the affected individual may have difficulty in controlling the seizures and as the result may develop problems with thinking and movement.
References
http://www.epilepsy.com/learn/types-epilepsy-syndromes/progressive-myoclonic-epilepsies
https://rarediseases.org/rare-diseases/progressive-myoclonus-epilepsy/
http://www.epilepsy.com/learn/types-seizures/myoclonic-seizures
http://www.epilepsy.com/learn/types-epilepsy-syndromes/juvenile-myoclonic-epilepsy
