What is a seizure threshold - and what does it mean for you?

  • September 27, 2023
  • 4
In this article
Doctor explaining seizure thresholds to a patient

If you have epilepsy, then you’ll want to avoid having seizures as much as possible. And this is why it’s helpful to think about your personal seizure threshold. Your seizure threshold can influence how likely you are to have a seizure. So, if you take actions to avoid crossing that limit, then it could help reduce the number of seizures you have. 

Let’s learn more. 

What is the seizure threshold?

Our bodies are continually working to balance the electrical activity in our brain cells. Certain chemicals increase the amount of ‘excitatory’ activity, while others ‘inhibit’ it (slow it down). In a seizure, there is either too much excitatory activity, or too little inhibitory activity. This could mean that your brain passes the seizure threshold, and there is a sudden discharge of electrical activity. 

Learn more: What happens in your brain during a seizure?

Technically, anyone can have a seizure. But most people have relatively high seizure thresholds, which means that their brains are able to balance the excitatory and inhibitory activity. But people with epilepsy have a lower seizure threshold, so the chemicals in their brains are more likely to get out of balance. 

Put simply, a seizure threshold is the point at which the chemicals in your brain become unbalanced and you become more likely to have a seizure. 

What might lower the seizure threshold if you have epilepsy?

If you have epilepsy, then it means you have a lower seizure threshold than other people. There are several things that can make you more likely to cross the seizure threshold. 

Seizure triggers

Many people with epilepsy find that certain experiences or things increase their chances of having a seizure. By avoiding these triggers, you may reduce the risk of crossing your seizure threshold. 

  • Tiredness: Feeling tired is a major seizure trigger. By getting as much sleep as you need, you may reduce the risk of having a seizure. 
  • Stress: Feeling stressed is a well-known seizure trigger. Taking steps to reduce stress can really help. 
  • Flashing lights: People with photosensitive epilepsy can reduce their risk of seizures by avoiding places where they are exposed to flashing lights. 

More triggers: 7 common seizure triggers

Medications that lower seizure threshold

There are many different medications that are believed to lower the seizure threshold in people with epilepsy. They may have an excitatory or inhibitory effect, or they may reduce the effectiveness of your epilepsy medication. These include:

  • Opioids: The effects of painkillers like codeine, morphine and tramadol on seizure threshold are well known. 
  • Antidepressants: Side effects of medication like Wellbutrin on seizure threshold are also an issue. 
  • Antimalarial drugs: Some antimalarials like chloroquine may affect the seizure threshold.
  • Over the counter medication: Some medications that you don’t need a prescription for can reduce seizure thresholds, including aspirin, pseudoephedrine (found in some cold medicines) and diphenhydramine (which is found in medicines like Benadryl). 
  • Antibiotics: Certain antibiotics, such as penicillin may lower seizure threshold. 
  • Some anti-seizure medication: When taken at the wrong dosage, some anti-seizure medications can actually increase your chance of having a seizure too. 

If you have epilepsy, always talk to your doctor or a qualified pharmacist before taking a new medication. They can check if the medication could have an effect on your seizure threshold. 

Other factors that may reduce seizure threshold

There are several other factors that may lower your seizure threshold if you have epilepsy:

  • Menstruation: Many menstruating women find they have more seizures around their periods. 
  • Alcohol: Many people with epilepsy find they have more seizures the day after drinking alcohol
  • High temperature: Being hot (due to warm weather or a fever) can increase your chances of having a seizure. 
  • Recreational drugs: Certain drugs, such as cocaine, can increase your chances of having a seizure. 

Being aware of your seizure threshold

Although it’s not possible to monitor your seizure threshold in real time, there are many things you can do to reduce the chances of crossing it. For many people, taking their anti-seizure medication regularly can be an effective way of increasing their seizure threshold. Or, if epilepsy medication doesn’t work for you, there are other methods that can also help with seizure management too. 

To stay on top of your seizures, it can be very helpful to keep a seizure diary. You can make a note of when seizures happened, what you were doing beforehand, and how you felt. That can give you an idea of what your seizure triggers might be - and help you to avoid situations where you might cross your seizure threshold. 

You can use Epsy to record seizures, auras, and your mood or feelings, as well as to remind you to take your medication. Try Epsy today for free.

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