What Is a Myoclonic Seizure?
It is a type of seizure where the muscles suddenly contract to cause quick twitching movements. An individual stays conscious during a myoclonic seizure attack. In most people, it involves the neck, shoulders, and upper arms of one side of the body, though rarely, it may affect the whole body. The underlying cause of myoclonic seizures is genetic factors. And it may be accompanied by cognitive and developmental problems as well.
What Are the Causes of Myoclonic Seizures?
The possible causes of myoclonic seizures are:
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Genetic mutations- Those with a family history of epilepsy are at a higher risk.
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Structural abnormalities in the brain at the time of development.
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Tumors in the brain.
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Infections involving the brain.
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In traumatic head injury.
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Inadequate oxygen supply to the brain.
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In many individuals, the cause remains unknown.
How Can One Recognize the Signs and Symptoms of a Myoclonic Seizure?
The seizure attack is so short that often one may mistake it for a nervous reaction, simple muscle tics, or just going clumsy. Several myoclonic seizures may occur one after the other in clusters too. Myoclonic seizures may occur along with atonic seizures, which can cause sudden limpness in the body. One may fall suddenly (drop attack). The myoclonic jerks happen first, followed by a sudden loss of muscle tone. This is called a myoclonic atonic seizure. In the majority of individuals, a myoclonic seizure presents as:
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A quick jerking of muscles.
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Multiple rhythmic movements of the affected part.
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An electric shock-like sensation.
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Clumsy behavior.
What Are the Different Types of Myoclonic Seizures?
Myoclonic seizures appear as a part of the following epilepsy disorders:
1) Juvenile Myoclonic Epilepsy (Janz’s Syndrome)
It normally starts in adolescence between the ages of twelve to eighteen. People with juvenile myoclonic epilepsy have a higher-than-average chance of having a family member who has epilepsy. In the long run, they may have tonic-clonic seizures as well. This means the person may need treatment for life. In individuals with juvenile myoclonic epilepsy:
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Seizures usually involve the neck, shoulders, and arms.
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Occurs mostly while waking up from sleep.
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Often begin in early puberty or adulthood.
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It can be controlled with medication, but most often, seizures continue throughout the person’s life.
2) Lennox-Gastaut Syndrome (LGS)
It is a rare neurological disorder characterized by many seizures, including the myoclonic type. It usually starts between the ages of two to six and affects children with neurological disorders, traumatic brain damage, and developmental anomalies in the brain. The child may get atonic seizures, tonic seizures, generalized tonic-clonic seizures, and absence seizures, along with myoclonic seizures. One may also have severe learning disabilities and physical limitations. Myoclonic seizures associated with LGS involve:
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Jerking movements of the neck, shoulders, upper arms, and face.
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They are strong and difficult to control.
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One may require many types of treatments, such as surgery and a keto diet along with anticonvulsant medication.
3) Progressive Myoclonic Epilepsy
In progressive myoclonic epilepsy, the symptoms usually start in late childhood or adolescence. It is a rare form of seizure consisting of different epilepsy syndromes. Progressive myoclonic epilepsy syndromes are caused by gene mutations. It is called progressive as it may get worsened over time. They include:
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Conditions such as Lundborg disease, Lafora disease, sialidosis, and neuronal ceroid lipofuscinoses.
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Developmental and physical impairments, as well as learning disabilities, depend on the severity of the syndrome.
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An individual with progressive myoclonic epilepsy usually has a short life expectancy.
How Is a Myoclonic Seizure Diagnosed?
A myoclonic seizure is often associated with other symptoms in individuals. It is essential to consult with a doctor and obtain a proper diagnosis. The doctor will evaluate the medical history and ask about the nature of symptoms at the time of the seizure attack. Since most types of myoclonic seizures are genetically passed on to the next generation, discussing family history with the doctor is very important. The additional diagnostic tests include:
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An electroencephalogram (EEG) is where one attaches electrodes to the patient’s scalp to understand the pattern of the brain’s electrical activity. This helps identify the part of the brain where seizures originate.
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Imaging studies like computed tomography (CT) scan or magnetic resonance imaging (MRI) help identify structural abnormalities and tumor-like lesions inside the brain, which may start a seizure.
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A lumbar puncture (spinal tapping) procedure is where the doctor inserts a needle into the spine to extract a sample of the cerebrospinal fluid (CSF). The fluid is examined for signs of infections or tumors.
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The doctor may order blood tests, too, to analyze signs of infections, electrolyte imbalance, etc.
How Is a Myoclonic Seizure Treated?
Most myoclonic seizures are difficult to treat and require multiple treatment modalities. The doctor may suggest a combination of the following treatments:
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Common anticonvulsant medications such as Valproic acid, Levetiracetam, Zonisamide, and Benzodiazepines. For juvenile myoclonic epilepsy, one may prescribe Topiramate or Lamotrigine as well.
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Special diet plans like the keto diet or Atkins diet which has low carbohydrates but are rich in fats.
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A vagus nerve stimulator is often used to control seizures as well. Here an electrical stimulator is attached behind the neck to pass on electrical signals into the brain.
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Lifestyle modifications like taking timely meals, getting adequate sleep, adopting stress management practices, avoiding lights that flicker inside the room, and limiting alcohol usage.
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Rarely may one recommend surgery to remove the malfunctioning area of the brain from which the seizures originate.
Conclusion:
Childhood myoclonic epilepsy often progresses into full-blown seizures (tonic-clonic) as they reach adulthood, adding to further complications to the individual's health. Myoclonic seizures are often brief and can easily be mistaken for tics or tremors. Hence, doctors often recommend that the caregivers of the affected individual keep a journal and write down the date and time when a seizure takes place and document how long the seizure lasted and what it looked like. Sharing this information with the physician can help them find the right treatment for the person having a seizure.
