Your seizure threshold is one factor that influences your likelihood of having a seizure. People with epilepsy tend to have a lower seizure threshold, meaning they’re more likely to have seizures. Some activities, conditions, and medications can lower this threshold.
A seizure occurs when your brain experiences a sudden surge of disorganized electrical activity.
Although anyone can have a seizure, people with epilepsy generally have a lower seizure threshold than people without the condition. This means certain triggers can more easily cause a seizure in someone with epilepsy.
This article explores the seizure threshold, including factors that can raise or lower your seizure threshold.
Anyone can have a seizure, given the right conditions, even if they don’t have epilepsy.
In general, some people are more likely than others to experience seizures. In other words, they have a lower seizure threshold.
No single factor determines your seizure threshold. Instead, it’s a combination of factors, starting with your genes. For example, people with epilepsy are more likely to have a family history of seizures.
Other factors that can influence your seizure threshold include:
- autism spectrum disorder
- brain infections
- brain injuries
- brain tumors
- cardiovascular diseases
- cerebral palsy
- complications during your birth
- dementia and other neurodegenerative conditions
- previous seizures
- sleep disorders
- substance use
In many cases, though, it’s not possible to identify the causes of seizures.
Defining seizure threshold
“Seizure threshold” typically refers to your brain’s likelihood of having a seizure. But experts sometimes use the term in the context of factors that can increase or decrease your risk of a seizure, such as medication.
There’s no way to know exactly what your seizure threshold is, but it might be lower than usual if you’ve recently experienced several known seizure triggers.
Most people have a stable seizure threshold, but some day-to-day physiological and environmental changes can increase or decrease your likelihood of having a seizure.
These factors are known as triggers. Some triggers are beyond your control, such as hot weather. Others relate to your lifestyle, emotional state, or diet.
If you have epilepsy, you might be aware of your seizure triggers, which vary from person to person.
Your seizure threshold might be lower than usual if you experience several triggers, such as brain surgery or a stroke, in a short period. If you haven’t experienced any triggers, your threshold might be at its typical level.
But it’s important to note that it’s not possible to pinpoint what your seizure threshold is at a particular moment in time. Medical professionals also sometimes use this term when discussing medications that can increase or decrease your risk of a seizure.
What can trigger a seizure?
Seizure triggers are factors that can cause a seizure. They vary from one person to another. Triggers are more likely to cause a seizure if you have a low seizure threshold.
Common seizure triggers include:
- caffeine, alcohol, or drug withdrawal
- fasting or eating too much
- flashing lights or images
- hot showers or baths
- an infection or fever
- ingredients in foods
- missed medication
- nutritional deficiencies
- recreational drug use
- sleep deprivation
- stress, excitement, or emotional upset
- warm weather or a sudden change in temperature
Many common prescription medications can lower your seizure threshold. You might be more likely to experience seizures if you take them.
Medications that may lower your seizure threshold include:
- anesthetics such as lidocaine, bupivacaine, and propofol
- antibiotics such as penicillin
- antimalaria drugs, including mefloquine and chloroquine
- antipsychotics such as clozapine
- antiepileptic drugs such as carbamazepine, gabapentin, and lamotrigine
- antituberculosis medication
- bronchodilators such as theophylline and aminophylline
- nonsteroidal anti-inflammatory drugs such as aspirin and diclofenac
- opioids such as tramadol, codeine, and morphine
Most of the time, a higher dose is more likely to lower your seizure threshold. In fact, small doses of some of the above medications may actually reduce your risk of seizures.
Antiepileptic drugs, for example, can help prevent seizures when taken in appropriate doses. They are likely to cause seizures only if you take more than your doctor prescribes. But in some people, these medications can trigger certain types of seizures.
If you have an increased risk of experiencing seizures, your doctor can help you weigh the risks and benefits of taking medications that may affect your seizure threshold.
In animal studies, the following therapies have led to an increased seizure threshold:
- brain stimulation
ellagic acid, which is an antioxidant
- branched-chain amino acids, which are nutrients found in meat, dairy, and legumes
- thiamine (vitamin B1)
- cannabidiol (CBD)
While these methods may provide options for treating epilepsy in the future, no human trials have yet taken place. More research is needed.
You can reduce your likelihood of seizures by avoiding known triggers when possible. For example, some people experience seizures when their blood sugar falls too low (hypoglycemia). They can reduce their chance of having a seizure by eating regular meals.
But remember that while you can take steps to avoid triggers, it is not possible to prevent all seizures.
Tips for preventing seizures
The following tips may also help prevent seizures:
- Make an effort to manage stress and anxiety through exercise and other relaxing activities.
- Maintain a regular sleep schedule.
- Avoid alcohol and other recreational drugs.
- Follow your medication regimen.
- Keep a seizure diary to identify and eliminate additional triggers.
Anyone may experience a seizure, but some people are more likely to have seizures than others. If you regularly experience seizures, you might have a low seizure threshold.
It’s not possible to identify your seizure threshold. Instead, doctors use this term when discussing medications and other factors that increase or decrease your risk of experiencing a seizure.