What is Generalized Tonic-Clonic Seizure?
A generalized tonic-clonic seizure, previously referred to as a grand mal seizure, is a type of seizure that starts with a period of strong muscle stiffening (the tonic phase), followed by rhythmic muscle jerking (the clonic phase). This kind of seizure is often the most worrisome for patients, families, and onlookers, as it typically comes with a reduction in awareness or even complete loss of consciousness.
The International League Against Epilepsy (ILAE), a group of experts on seizures, classifies these seizures as starting all at once across the entire brain (generalized onset). They further split generalized onset seizures into two categories: motor (movement-related) and non-motor (like absence seizures where people appear to ‘zone out’). Under these classifications, a generalized tonic-clonic seizure is classed as a motor seizure and is the most common type seen in people with epilepsy.
These seizures start and quickly spread throughout different brain networks, involving both sides of the brain, deeper brain structures, as well as the brainstem. Sometimes, a seizure that begins in one side of the brain, known as a focal seizure, can quickly spread across the whole brain. When this happens, it’s known as a bilateral tonic-clonic seizure (previously known as a secondary generalized seizure). This can sometimes be hard to tell apart from a primary generalized tonic-clonic seizure that starts all across the brain at once.
What Causes Generalized Tonic-Clonic Seizure?
The main cause of most “generalized tonic-clonic seizures” (sudden, violent seizures affecting the entire body) is a condition called epilepsy. Often, this epilepsy is inherited, or passed down through families. However, these types of seizures can also be a result of epilepsy caused by physical changes in the brain, infections, metabolism issues, or problems with the immune system.
Sometimes, seizures can be caused by a sudden, serious event, like a stroke, bleeding near the brain, a head injury, a severe lack of oxygen, a serious medical condition, shifts in the body’s chemical balance, or drug misuse. These seizures occur out of the blue, and don’t usually happen again.
Meanwhile, seizures caused by epilepsy often tend to happen more than once, even without any clear triggers. It’s common for people to end up in the emergency room after having a seizure, and the most typical causes of these visits are alcohol and drugs, head injuries, and epilepsy.
Risk Factors and Frequency for Generalized Tonic-Clonic Seizure
Seizures are a relatively common reason for emergency visits in the U.S., making up 1-2% of all cases. Around 11% of Americans will experience a seizure at some point during their lives. Men are more likely to have seizures than women, with a risk ratio of 1.85 to 1. This means that about 5% of men and 2.7% of women are likely to have a seizure in their lifetime.
When it comes to emergency visits due to seizures, African Americans are more likely to be patients than white individuals, with a risk ratio of 1.4. Additionally, seizures often occur at two specific life stages: in infants, typically as a result of feverish illness, and in individuals over age 75, usually due to brain damage from incidents like strokes or trauma.
Signs and Symptoms of Generalized Tonic-Clonic Seizure
A generalized tonic-clonic seizure diagnosis is primarily established based on the symptoms mentioned by the patient and physical examinations by a doctor. To begin with, doctors concentrate on what the patient can recall about their seizure experience. Doctors also ask about ‘auras’, which are early signs of an upcoming seizure. Auras may include changes in mood, cognition, and even headaches. The presence of auras can help doctors in finding where the seizure is originating from and are indicative of a certain kind of seizure known as focal onset seizures.
If a person has experienced their first tonic-clonic seizure, doctors will inquire about any prior unusual staring spells or early morning muscular twitching. This is because such incidents could help diagnose epilepsy or a certain type of epilepsy syndrome. Generalized tonic-clonic seizures usually start instantly with a loss of consciousness, without presenting any early signs. This type of seizure commonly starts with a yell or scream, followed by the entire body turning stiff, which may or may not be accompanied by the person’s skin turning blue. After this ‘tonic’ phase, the symptoms progress to include uncontrollable bodily jerking, and finally, the person may feel very sleepy, confusion or agitated.
It is also important for doctors to understand the circumstances around the seizure – such as whether it was triggered by fever, a lack of sleep, stress, strong emotions, intense physical activity, loud music, or flashing lights. Also, a thorough physical examination is critical in diagnosing a tonic-clonic seizure.
- Medical examination usually reveals that the patient is confused, sleepy, has a headache and may show personality or mood alterations. These are all typical signs following a generalized tonic-clonic seizure.
- About 22% of patients with these seizures may have bite marks on the sides of their tongues which don’t typically occur with non-epileptic seizures.
- Scratches and bruises may also be present on a patient’s body.
- A patient might complain about back pain after a seizure related fall, this could indicate a vertebral compression fracture.
- Other significant signs that doctors look for include stiffness in the back of the neck due to inflammation from a bacterial or viral infection, a hand-flapping tremor called ‘asterixis’ caused by metabolic disorders, and any weakness or asymmetry which suggests the seizures might be starting in one part of the brain before spreading.
- The patient may also have signs of urinary incontinence caused by the relaxation of the urinary sphincter during a seizure.
- Skin examinations may also reveal signs of neurocutaneous syndromes like neurofibromatosis, tuberous sclerosis, and Sturge-Weber syndrome – these are all linked to epilepsy.
Testing for Generalized Tonic-Clonic Seizure
If you visit the emergency room, certain tests may be conducted to check for specific conditions. These include a blood test, called a chemistry panel, which will help doctors rule out low blood sugar (hypoglycemia), low sodium in the blood (hyponatremia), high levels of urea in the blood (uremia), and possible drug intoxication.
If the doctors think there may be something serious happening with your brain, they might also recommend a procedure called neuroimaging. One form of this is a CT scan, which is like a fancy X-ray and helps doctors get a detailed look at your brain. It’s usually the first choice in an emergency situation.
If the CT scan doesn’t show anything but the doctors still think something might be wrong, they might conduct an MRI. An MRI, which uses magnetic fields to get detailed images of your body, helps check for abnormalities that a CT scan might have missed.
Sometimes, doctors might also recommend an electroencephalography (EEG) test. This is used, for example, if you had a seizure but haven’t returned to your normal state after about 30 – 60 minutes, or if you have changing mental status or weakness on one side of your body, and these conditions can’t be explained by changes in the structures of your brain.
Lastly, if doctors are concerned about certain diseases that can affect your brain, such as meningitis (swelling in the layers that cover the brain and spinal cord), encephalitis (swelling in the brain), or a type of stroke known as subarachnoid hemorrhage (bleeding in the space around the brain), they might conduct a procedure called a lumbar puncture. This involves inserting a needle in your lower back to collect cerebrospinal fluid, which bathes the brain and spinal cord, to check for signs of these diseases.
Treatment Options for Generalized Tonic-Clonic Seizure
If someone is experiencing tonic-clonic seizures, it’s important to turn them over to their side. This recovery position can help avoid suffocation and the risk of them breathing in and choking on their own saliva, vomit, or other fluids. Even though most of these seizures stop on their own, it’s often recommended that the person has an intravenous (IV) line, a small tube inserted into their vein, for quick access if the seizures don’t stop. The doctor will also check for other problems that might be causing the seizures, like infections or metabolic disorders, which are both treatable.
A seizure is considered status epilepticus, a serious condition where seizures occur one after the other or last more than 5 minutes, if the seizures don’t stop or if the person doesn’t regain consciousness. In these cases, deciding what to do fast is crucial. The person’s airway, breathing, and blood circulation need to be assessed, and the brain functions need to be checked while looking at a display of the brain’s electrical activity using an electroencephalogram (EEG), if available. Doctors may also check to make sure the blood sugar is normal, obtain IV access, and order labs to check for imbalances in electrolytes (minerals that help body functions), look at blood cells, test for drugs, and measure antiseizure medication levels, if necessary.
For someone critically ill from repeated or non-stop seizures, doctors often give antiseizure medication through the IV line to quickly get enough the drug into the bloodstream. The initial medication choice is usually a benzodiazepine type, which helps calm the brain’s electrical activity. Types of benzodiazepines include midazolam, which can be given as an injection into the muscle, through an IV, or sprayed into the nose; lorazepam and diazepam, both given through an IV; or diazepam given through the rectum. If seizures continue after 20 minutes, a second medication is chosen, such as fosphenytoin, valproic acid, or levetiracetam, but there is no specific preference for which one of these is best.
The decision to start regular preventive antiseizure medication depends on many factors, including whether the event turned out to be a seizure, confirmation of a seizure based on the person’s symptoms and physical exam, the person’s stability, and risk that seizures might happen again. Epilepsy surgery, which is an operation to control hard-to-treat seizures, could be an option for those with seizures that start in one part of the brain, but usually isn’t considered for seizures that involve the entire brain.
What else can Generalized Tonic-Clonic Seizure be?
When someone has symptoms that look like a seizure, there could be other conditions causing these symptoms. Doctors need to rule these out to correctly identify if it’s a seizure or something else. Conditions that can mimic a seizure include:
- Syncope (fainting, whether because of heart issue or not)
- Transient ischemic attack (a “mini-stroke”)
- Psychogenic non-epileptic seizure (a psychological condition that causes seizure-like symptoms)
- Paroxysmal movement disorders (conditions that cause sudden, involuntary movements)
- Sleep disorders
- Migraine
What to expect with Generalized Tonic-Clonic Seizure
The outlook for someone having generalized tonic-clonic seizures greatly depends on what caused the seizure and the person’s risk factors. Typically, based on research studies, the chance of having more seizures is about 40%. The likelihood of experiencing another seizure tends to be highest right after the first seizure and gradually reduces as more time has passed since the incident.
Research has found that starting medication treatment can reduce the chance of seizures by roughly 30% to 60%. Three factors, however, have consistently been associated with a higher chance of more seizures: the number of previous seizures someone has had, presence of a neurological disorder, and abnormal readings on an electroencephalogram (a test that measures electrical activity in the brain).
Possible Complications When Diagnosed with Generalized Tonic-Clonic Seizure
People who have generalized seizures characterized by muscle stiffness (tonic) and jerking (clonic) are more likely to have mental health issues, problems with thinking and memory, sleep disorders, heart disease, issues with their bones, physical injuries, and a higher risk of dying prematurely. One specific risk associated with these seizures is ‘sudden unexpected death in epilepsy’ (SUDEP). People diagnosed with generalized tonic-clonic seizures are at a higher risk for SUDEP. The exact cause of SUDEP is yet to be determined, but it is thought that it might be caused by irregular heartbeats, seizure-induced stoppage of breathing, lung issues and sudden depression of heart and lung activity triggered by the brain.
It is crucial to note that there is no guaranteed way to prevent SUDEP; however, managing seizures better and having someone to monitor the patient at night may help.
Possible Issues:
- Mental health issues
- Cognitive impairment (problems with thinking and memory)
- Sleep disorders
- Heart disease, bone disease
- Physical injuries
- Premature mortality
- Sudden unexpected death in epilepsy (SUDEP)
Potential Causes of SUDEP:
- Heart arrhythmia (irregular heartbeats)
- Seizure-induced apnea (stoppage of breathing)
- Pulmonary dysfunction (lung issues)
- Neurogenic cardiorespiratory depression (sudden depression of heart and lung activity driven by the brain)
Possible prevention measures:
- Better seizure control
- Nocturnal supervision
Preventing Generalized Tonic-Clonic Seizure
If you’ve been diagnosed with generalized tonic-clonic seizures, this condition may greatly affect your day-to-day life, job, driving capabilities, and self-confidence. It’s important to address both mental and emotional concerns as well as managing the physical symptoms of seizures. Your doctor or medical professional will usually guide you on how to evade common triggers of seizures like lack of sleep, drinking alcohol, certain medications, and your state of alertness during general sickness.
You should also avoid doing certain activities alone like swimming, working in high places, and operating heavy machinery. This is to avoid potential dangers like drowning or getting injured if a seizure happens while doing these activities. With respect to driving, the restrictions may vary based on where you live. Nonetheless, most places require a period of not driving after experiencing a generalized tonic-clonic seizure.
