Myoclonus epilepsy refers to sudden and involuntary twitching of a group of muscles. It is an indication of a medical condition and is not a diagnosis in itself.
Myoclonus is a condition in which a group of muscles begin alternating between contractions and relaxations. In the literary terms, ‘myo’ means muscle and ‘clonus’ refers to the action of alternate contraction and relaxation. Positive myoclonus refers to contraction, while negative myoclonus is signified by relaxation of a muscle group. Myoclonus epilepsy is highly irregular in nature. It may be frequent or occasional, in patterns or without patterns, and may arrive as a singular attack or as multiple ones.
Myoclonus jerks, hiccups, and ‘sleep starts’ are very common and happen to all normal individuals. However, there are some serious forms of myoclonus which may make activities like sleeping, eating, or talking difficult for an individual.
Myoclonus epilepsy usually brings about sudden movements in both sides of the body. The causes of this condition are myriad. From infections and injuries in brain/spine to tumors, anything can cause this condition. Moreover, sleep deprivation and psychological stress are some other factors that can contribute to the seizures. This is the reason, why it is treated as an idiopathic condition, meaning there is no known cause for it. It is characterized by four types, which are as follows.
Juvenile Myoclonic Epilepsy
This type involves muscle twitching in neck, shoulders, or upper arms. Mostly, the seizures begin immediately after waking up. The individual gets his first attack of juvenile myoclonic epilepsy (JME) during puberty or early adulthood. Mostly, people with normal intelligence are likely to be affected with JME. This type can be controlled with the help of medications however, it is imperative to continue these medications throughout the lifetime.
Progressive Myoclonic Epilepsy
Progressive Myoclonus epilepsy (PME) encompasses a plethora of conditions and represents an array of diseases and disorders. It is different from JME in a number of ways. In JME, jerking occurs as an integral part of the seizure, while in PME, it occurs differently. Thus, the seizure and PME, respond differently to the drugs and also evolve as independent medical conditions. PME is chronic and the condition of the patient deteriorates over time. It rarely responds to the medications and there are very less chances of the patient returning to normalcy. In fact, certain medications like phenytoin and carbamazepine are known to make PME worse.
This is a pretty uncommon type of myoclonus epilepsy, and it often includes other forms of seizures. Mostly, it occurs during early childhood. The seizures are pretty severe and occur mostly in the upper half of the body.
Myoclonic Astatic Epilepsy
Myoclonic astatic epilepsy or Doose syndrome is fairly rare and affects about 2 out of 100 children suffering from epilepsy. It is characterized by frequent seizures which end in the patient collapsing to the ground. Often, there are periods when consciousness is lost for a brief time. Though, the response to medications is fairly good, the child is likely to have significant learning difficulties in his life. However, in certain cases, the seizures can be controlled considerably and the child may report average learning skills.
Myoclonus epilepsy manifests in several forms. As mentioned before, it is a symptom and not a disease in itself. Therefore, it is important to accurately diagnose the underlying disease, so as to treat it effectively.