Atonic seizures (also known as gout attacks) are one of several types of seizures that can result from various underlying causes. Atonic means loss of muscle tone. This type of seizure is also known as a drip or akinetic seizure.
Atonic seizures often begin in childhood and are more common in children, although they can continue into adulthood. This type of seizure is common in people who also have other types of seizures, such as tonic or myoclonic seizures.
Atonic seizures are rare and account for less than 1% of all seizures .
Neurons or nerve cells in the brain constantly communicate with each other, transmitting electrical impulses from one to the other. Voluntary and involuntary movements are controlled and regulated by these nerve transmissions.
A seizure is the result of the brain receiving abnormal electrical signals that disrupt the brain's normal electrical function in the nerve cells that control muscles. First of all, there are two types of seizures: generalized and focal . The difference is mainly where they start in the brain.
Generalized seizures affect the entire brain and then the entire body. They can also cause seizures (involuntary movements), but some generalized seizures (such as absences) do not cause seizures. There are six types of generalized seizures:
- Absence (petit mal)
- Tonic-clonic (big bad)
Focal seizures (also called partial seizures) are seizures that start in one part of the brain and affect the part of the body that is controlled by that part of the brain. Depending on the type of seizure, an atonic seizure can also be focal.
What are atonic seizures?
Usually when you are sitting or standing, your muscles contract slightly. This allows the body to remain upright.
In an atonic seizure, a person's muscles do not contract, as in the more well-known types of seizures called tonic-clonic types (convulsive or large).
In fact, the muscles relax so much that the person with atonic seizures often falls forward because the muscles cannot support the body. If they stand up, they will fall to the ground.
If a person is sitting, their head may drop as a result of an atonic seizure. This is also typical for babies who are too young to stand. It can be difficult to detect an atonic seizure in a person lying down, except that they become lethargic and unresponsive.
Atonic seizures are less common than many other types of seizures, but they can occur along with other types .
An atonic seizure can begin with one or more myoclonic jerks. This type of seizure is usually short-lived and occurs without warning. Recovery is also usually quick (with the exception of injuries that can result from falls). Atonic seizure falls often result in injuries to the face and head.
In atonic seizures, a person's muscles suddenly become flaccid.
Types of atonic seizures
Atonic seizures can be classified as focal seizures (beginning in one part of the brain) that cause loss of muscle tone in only one part of the body. This is called a focal motor atonic seizure .
When an atonic seizure begins on both sides of the brain, it is called a generalized atonic seizure seizure . In most cases, atonic seizures are generalized seizures. Generalized atonic seizures begin with a sudden loss of muscle tone in the head, trunk, or the entire body.
Atonic seizures often cause loss of consciousness. This type of seizure usually lasts less than 15 seconds, but can last up to several minutes. After an atonic seizure, the person quickly regains consciousness.
Symptoms of atonic seizures can include :
- Sudden loss of muscle strength
- I lose strength and fall to the ground
- When sitting, the person's head drops suddenly.
- Remain conscious or experience loss of consciousness in the short term.
- Droopy eyelids
- Nod your head
- Jerking motion
Anything that interrupts the normal transmission of nerve impulses in the brain can lead to a seizure. This could include:
- High fever
- Low blood sugar
- High blood sugar level
- Abolish alcohol or drugs
- Concussion (from head injury)
- Some types of diseases
- A brain tumor
- Other factors
Common causes of seizures in babies include:
- An imbalance in neurotransmitters (chemical messengers in the brain)
- A brain tumor
- Brain damage, usually due to illness or injury .
- Low blood sugar
- Use of certain medications by the mother during pregnancy.
- Birth injury, including oxygen deficiency (hypoxic-ischemic encephalopathy)
- Low levels of calcium or magnesium in the blood.
- Infections such as meningitis or encephalitis.
- A brain hemorrhage (bleeding) that may be associated with very early labor.
- Fever (usually not associated with epilepsy)
- Other unknown factors
Risk factors and triggers
The underlying cause of atonic seizures is often unknown. Changes in genes may be associated with an increased risk of atonic seizures. In fact, researchers have identified nearly 1,000 genes involved in epilepsy .
Most of the time, children are prone to atonic seizures, but these types of seizures can occur at any age. Triggers for atonic seizures can include hyperventilation (rapid breathing) and / or flashing lights.
Atonic seizures in epilepsy
When a person has two or more seizures of any kind, they are diagnosed with epilepsy of unknown cause.
Epilepsy affects approximately 3.4 million people in the United States, according to the Centers for Disease Control and Prevention. It is one of the most common disorders of the nervous system.
Atonic seizures are usually a type of seizure that occurs with certain types of epilepsy, such as Lennox-Gastaut syndrome (LGS) and Dravet syndrome (SD).
LGS is a severe childhood epilepsy that includes:
- Medication-refractory seizures (when medications do not relieve seizures)
- Falling attack (atonic seizures)
- Atypical absences
Atypical absences include a less abrupt onset of seizures than typical absences associated with loss of muscle tone in the trunk, extremities, or head and gradual decline, as well as mild myoclonic contractions.
Dravet syndrome (DM) is a serious form of epilepsy that includes symptoms such as :
- Frequent and prolonged cramps, often caused by high body temperature (pyrexia).
- Developmental delay in infants and children
- Speech disability
- Ataxia (loss of complete control over body movements)
- Hypotension (abnormally low levels of muscle tone)
- Sleep disorders
- Orthopedic conditions
- Chronic infections
- Dysautonomia (disorders of homeostasis)
- Other health problems
When to contact a healthcare provider
The first time someone has a seizure (of any kind), the healthcare professional should be notified immediately and diagnostic measures should be taken, including a medical history and physical exam.
It is important for a person diagnosed with epilepsy to seek immediate medical attention in any of the following scenarios:
- An attack that lasts more than five minutes.
- Breathing that does not return to normal after the seizure ends.
- Loss of consciousness that persists after the seizure ends.
- Second seizure that occurs after the first (cluster seizure)
- High temperature occurs
- Experience heat exhaustion
- The attack occurs during pregnancy.
- Every time diabetes is diagnosed
- When the injury was due to a seizure.
Every time a person has a seizure, the doctor needs to determine the type of seizure and the specific area of the brain. This is because the anticonvulsant regimen depends in part on the type and duration of the seizures.
Observer information (through written descriptions or videos) describing the event is an important part of the diagnostic evaluation.
The electroencephalogram (EEG) is the main diagnostic tool used to diagnose seizures. An EEG procedure involves placing electrodes on the scalp to measure electrical activity in the brain and detect abnormal patterns.
By looking at these patterns, different types of seizures can be identified . EEG tests are also done to measure the effectiveness of anticonvulsants by evaluating how they help with electrical malfunction in the brain.
Magnetic resonance imaging (MRI) and computed tomography (CT) are also used to study important factors, such as where in the brain a seizure occurs. This scan is often used to rule out possible causes of seizures, such as a stroke.
If the diagnosis is unclear and anticonvulsants are not effective, tests can be done to discover other sources of the problem that may be causing the falls.
The goal of treatment for atonic seizures is to control, reduce the frequency, or stop the seizures without interfering with the person's normal activities. Treatment of atonic seizures depends on many factors, including:
- Correctly identify the type of seizure
- Assessment of seizure frequency
- Diagnosis of the underlying cause of the seizures (if possible)
- The person's age, health, and medical history
- Evaluation of the patient's tolerance to drugs and / or other treatments.
Factors that affect treatment options include:
- Treatment objectives
- Parental preference or seizures (in adult patients)
- Side effects
- The cost of medicine
- Compliance with medication regimen
In addition to medications, your doctor will likely advise you:
- Get enough rest to avoid lack of sleep (which can trigger seizures)
- Avoid other things that trigger an attack (such as flashing lights, fever, and heat exhaustion).
- Wear a helmet to protect your head from injury from a fall.
The treating physician will take into account several factors when prescribing anticonvulsant medications. This includes:
- Using an anti-seizure medication of the appropriate type for the type of seizure.
- Prescribe the lowest dose to control the seizure.
- Frequent blood and urine tests to ensure correct intake of medications.
Antiepileptic or anticonvulsant drugs are the most common form of treatment for seizures; however, it may take a while for the doctor to find the right medicine and the best dose for each person.
Types of anticonvulsants include:
- Ethosuximide (Zarontin), which is commonly used as the drug of first choice in the treatment of seizures.
- Valproic acid (Depaken), which is not recommended for women who are pregnant or of childbearing age, as this drug may increase the risk of birth defects.
- Lamotrigine (Lamictal), which may be less effective than ethosuximide or valproic acid, but has fewer side effects.
- Klobazam (Onfi)
Always take anticonvulsants exactly as prescribed by your doctor (including the scheduled time and dose). Discuss the possible side effects and report it to your doctor as soon as possible.
Expect several tests to measure the efficacy and safety of anticonvulsants. These tests can include:
- Frequent blood and urine tests to determine the optimal level (called the therapeutic dose) that works best to control seizures with minimal side effects.
- Other types of tests to measure the effectiveness of anticonvulsants in the body, such as an EEG .
Talk to your doctor about any activity restrictions due to side effects (such as drowsiness) caused by anticonvulsants. Many people taking these medications are advised to avoid heavy equipment.
Talk to your doctor or pharmacist before taking other medications (including over-the-counter ones), as they can interfere with how well anticonvulsants work or cause dangerous side effects.
Medications don't work for everyone, so your healthcare provider may recommend other treatments.
Studies have shown that the ketogenic diet can help control seizures in some patients who do not respond to medications. This low-carbohydrate, high-fat diet is most often used to treat children with epilepsy.
The ketogenic diet puts the body in a state of hunger due to a lack of carbohydrates and leads to a state of ketosis in the brain. It was discovered nearly a century ago, and for the past 30 years, research has confirmed its ability to reduce seizures in children who do not respond well to anticonvulsants .
"The link between metabolism and epilepsy has been a mystery," said Gary Yellen, Ph.D., professor of neuroscience at Harvard Medical School. He learned about the ketogenic diet through his wife, Elizabeth Thiele, MD, Ph.D., a professor of neurology at HMS, who directs the Pediatric Epilepsy Program at Massachusetts General Hospital for Children.
"I have met many children whose lives have been completely changed by this diet, it is surprisingly effective and it works for many children for whom drugs do not work," Yellen said.
For some people who do not respond well to medications, surgical options may be appropriate.
Vagus nerve stimulator (VNS): The VNS is a surgically implantable device that is sometimes implanted (and used in conjunction with anticonvulsants) to prevent seizures by sending small electrical impulses through a nerve in the neck called the vagus nerve to the brain.
A study published in 2013 found that while VNS was effective in reducing the frequency of certain types of seizures (tonic-clonic and myoclonic), it was ineffective in reducing atonic or tonic seizures in children with Lennox-Gastaut syndrome or syndrome of Lennox …
Corporal callosotomy: A surgical procedure called a corporeal callosotomy (CC) is an operation to interrupt abnormal electrical activity in the brain that spreads from one hemisphere to the other during a generalized seizure (such as an atonic seizure).
This is done by dissecting the corpus callosum, the region of the brain located between the two hemispheres. This usually does not stop the seizures; they continue on the side of the brain where the seizures begin.
Surgery is not recommended for everyone with atonic seizures, but it may be a good option for some. A 2015 study of patients with atonic seizures and falling attacks who underwent CC and VNS found that 58% of those with CC did not have atonic seizures after the procedure, compared with only 21.1% of participants of the study who had VNS implants .
The prognosis or expected result of atonic seizures depends mainly on the cause. Sometimes epilepsy syndromes (epilepsy of unknown cause) resolve as the child grows.
Generally, a child should not have a seizure for one to two years before the option of stopping the anti-seizure medication is considered. Adults generally need to get rid of seizures longer before healthcare professionals recommend stopping the medication. According to a 2019 study, the recommendation is for at least two years.
In other cases, a child with atonic seizures may need antiepileptic drugs for the rest of his life. Be sure to make this decision under the direction of your healthcare provider so that you do not take undue risk to your health.