Pen pointing at part of brain from scan.

Understanding seizures: Everything you need to know

Experiencing a seizure can be intense, confusing, and complicated. If you’ve experienced one, then you know that they can be difficult to accurately describe.

Almost everyone who experiences seizures experiences them in different ways, whether through the loss of control of motor skills, consciousness, or perhaps even been struck with sudden uncontrollable emotions such as fear or anxiety.

Thoroughly understanding seizures is an important step towards addressing these concerns and protecting the overall quality of your health and wellness.

What is a seizure?

Essentially, a seizure is a disturbance in the electrical and chemical activity of the brain. It’s a temporary experience that can result in uncontrollable changes in movement, awareness, behaviour, and/or feelings.

Any part of the brain could be affected by seizures, which is why their symptoms are so diverse. Normally, there’s a sort of balance between brain cells that fire off regularly in certain areas of the brain. Seizures upset this balance, largely because of surges of electrical activity that causes cells to fire off in unusual ways. This causes parts of the brain to function abnormally (not as they should), causing a temporary state of uncontrollable brain activity that can lead to a wide range of seizure symptoms.

One important thing to recognise is that having seizures does not necessarily mean you have epilepsy.

Seizures are often a symptom of complex chemical changes that can be triggered by various illnesses, injuries, and other events. They vary in severity and type, sometimes relatively harmless and other times severely dangerous.

Identifying parts of the brain from an MRI
[Image description: Hand holding a pen that is pointed towards a section of the brain on a brain scan, among many brain scans.]

Seizure symptoms

No one experiences seizures in quite the same way. You may be aware of them while they happen, or you may not. You may be significantly disabled, or it’s possible you may hardly notice them. Depending on the type and severity of the seizure, you may experience some combination of the following:

  • Loss of consciousness or awareness

  • Muscle contractions

  • Blank staring or rapid eye blinking

  • Confusion

  • Unusual body movements or jerking

  • Hallucinatory sights, sounds, or smells

  • Uncontrollable fear, rage, or other intense emotions

The length of time these symptoms go on can be unpredictable. They may happen quickly, lasting only a few seconds before vanishing. In other cases, they can last for several minutes. (Seizures lasting over five minutes are considered a medical emergency and an ambulance should be called.)

If you’re unconscious, chances are you’ll have no memory of the event afterwards. If you’re aware, or even partially aware, then there’s a chance you may or may not remember it. Some only remember the event partially, and others may experience prolonged confusion afterwards. It’s also common to experience prolonged feelings of sadness, anger, worry, or fatigue.

Seizure types

Understanding the different seizure types is important. A recent change in seizure classification now means that seizures are classified based on three (3) key features.

  1. Where the seizure begins in the brain (this is called onset)

  2. The level of awareness a person has during a seizure

  3. Whether the seizure involves other features, like movement

When these features are identified, doctors can describe a person’s seizures more accurately which helps them make a more accurate diagnosis.

Where a seizure begins

The area of the brain in which a seizure begins (onset) is how seizures are categorised.

  1. Generalised seizures — Both sides of the brain

  2. Focal seizures — One side of the brain

  3. Focal to bilateral seizures — Starts on one side and spreads to the other

  4. Unknown onset — The area where the seizure began is unknown

Generalised seizures

These types of seizures affect all parts of the brain, with brain cells firing abnormally in both cerebral hemispheres (both sides of the brain) at about the same time evenly. They’re generally associated with loss of awareness but can manifest in many different ways. Below are common generalised seizure types:

1. Tonic-clonic seizures

Previously referred to as grand mal seizures. This is the seizure type most people associate with an epileptic seizure. It is still described as a generalised tonic-clonic seizure and was previously called a grand mal seizure.

During the seizure the person will become unconscious, their body stiffens up (tonic) and their body will jerk rhythmically (clonic). Once the seizure ends the person may feel tired and confused.

2. Clonic seizures

These are associated with rhythmic or semi-rhythmic muscle contractions. This rhythmic jerking activity can affect the whole body (generalised clonic seizure), one side of the body or just one part of the body (focal motor seizures), depending upon where in the brain the seizure starts.

3. Myoclonic seizures

This variety consists of sudden brief contractions, usually lasting around one (1) second. The person experiencing the seizure remains conscious throughout and will feel the seizure as a sudden shock taking place in a muscle, or in a particular group of muscles.

4. Tonic seizures

Like myoclonic seizures, tonic seizures are brief, usually lasting less than 30 seconds. They induce muscle stiffness, often resulting in falls. This can occur in the entire body or in just a specific part of the body, depending upon where the seizure occurs in the brain.

You may remain aware or have a small change in awareness during a tonic seizure, particularly if it lasts more than a few seconds.

5. Atonic seizures

These are sometimes referred to as a “drop attack” because a sudden loss of muscle tone can often result in falling abruptly on the floor. Consciousness is often lost during the event but is normally recovered quickly afterwards.

Atonic seizures do not always affect the entire body, if the seizure is taking place in one part of the brain a loss of tone can occur to just one part of the body.

Though more frequent in children, adults are also known to have atonic seizures, though they are relatively rare.

6. Absence seizures

  • Typical absence seizures

Previously referred to as petit mal seizures. These seizures involve a sudden impairment of awareness, which means you will not respond to the people around you or changes in your environment.

The person experiencing the seizure will typically stop all activity and stair with a blank expression. Their eyelids may flutter and eyes turn upwards.

These seizures can be difficult to notice as they are brief (less than 10 seconds) and may just appear as a pause in typical behaviour and recovery is immediate.

Typical absence seizures are relatively rare, occurring more often in children than adults.

  • Atypical absence seizures

These differ from typical absence seizures because they last longer (around 20 seconds) and include additional symptoms such as automatic behaviours like chewing movements or rubbing fingers together. They can also sometimes result in a loss of muscle tone which increases the risk of falls.

Focal onset seizures

These kinds of seizures occur and remain in one particular region of the brain. Below are two examples of common forms of focal seizures:

1. Focal aware seizures

These were previously referred to as simple partial seizures. During this type of seizure, the person maintains awareness. The person is awake, alert and able to remember what they experienced during the seizure.

Some people are able to interact with their environment while the seizure is taking place, while some are aware of their environment but can’t move or respond until the seizure ends.

With focal aware seizures, you’re likely to experience changes in your five senses. You may also experience temporary sensations such as tingliness, dizziness, or visual flashes of light.

These seizures can last from seconds to around two (2) minutes. Some people describe these types of seizures as “auras” because they can sometimes lead into a different seizure type.

2. Focal impaired awareness seizures

These involve total or partial loss of consciousness or awareness. A variety of involuntary behaviours may accompany them such as chewing, lip-smacking, screaming, running, gagging, and others. This is usually followed by a postictal period (a period of time afterwards that includes additional symptoms) which can affect your mood and cognitive functions.

Some seizures can start in one part of the brain and spread to other parts of the brain, meaning they begin as focal seizures and continue to become generalised seizures. Those are called focal onset to generalised seizures.

Triggers and causes

Triggers of non-epileptic seizures

Many conditions that affect the brain have the potential to trigger seizures. Seizures triggered by these things are not thought to be epileptic seizures.

Below are some examples of things that affect the brain and could possibly trigger non-epileptic seizures

  • Drug and alcohol abuse

  • Metabolic problems

  • Ingesting toxins

  • Certain medications

Triggers of some types of epilepsy

Some types of epilepsy have seizures that can be triggered. Below are some things that can trigger these types of epilepsy.

  • Flashing or flickering lights

  • Certain sounds

  • Drug or alcohol withdrawal

  • Lack of sleep

  • Stress or other emotional changes

In addition to the above, it’s possible for seizures to occur without warning and with no indication of their cause.

In many of these cases, you’re likely to experience one seizure without ever having another. In all cases, consulting a doctor can help you determine the best course of action should any treatment be needed.

What causes a seizure?

Acquired epilepsy

Epilepsy can be acquired and cause seizures. Below are some examples of things that can actually cause epilepsy (but are not considered triggers to a person’s existing epilepsy.)

  • Brain injury

  • Stroke

  • Fever

  • Infection

  • Brain tumours

  • Head trauma

Idiopathic generalised epilepsy

Some types of epilepsy are believed to be rooted in genetics. They could be caused by:

  • Genetic conditions

  • Structural abnormalities in the brain

Doctor writing the word 'Epilepsy' with a marker
[Image description: Physician writing the word ‘Epilepsy’ using a black marker.]

Seeking medical help

Generally speaking, if you experience more than one seizure or if you experience one lasting more than a few minutes, it’s advised that you seek help from a doctor.

This is also true if you happen to experience any fever or heat exhaustion, prolonged loss of breathing or consciousness, and if you’ve had any injuries.

People who are pregnant or who have been diagnosed with diabetes should seek help immediately after any seizure activity.

What will your doctor ask you?

Your doctor will ask you to describe what happens to you when you experience a seizure. Since you may not have been conscious, it’s often helpful to have anyone who witnessed the event there with you. They’ll also be interested in what you felt just before and just after the seizure.

It’s always a good idea to keep track of your seizures—and it’s especially helpful to have a record of your events when you visit your doctor. This will help them determine the cause of your seizures, and maybe even identify triggers you may not already be aware of.

The important things to note when tracking your seizures are:

  1. Date

  2. Time

  3. Length of the seizure

  4. The weather at the time of the seizure

  5. Your mood just before the seizure

  6. Anything that may have changed in your regular environment

You can do this on any piece of paper or notebook, or you can use a seizure-tracking app on your phone to help you log events and take notes that could be helpful to your doctor.

How seizures are tested and diagnosed

When diagnosing your symptoms, most doctors will begin with a description of the event. Afterwards, most doctors will perform a neurological exam, which is a brief check of certain functions that your brain controls. It’s non-invasive and happens right within the doctor’s office.

Your doctor will then most likely order some tests that monitor your heart and brain activity, so that they can look for anything unusual. Depending on what you’ve described, they may suggest one or more of the following:

  • A CT or MRI

  • An electrocardiogram (ECG)

  • An electroencephalogram (EEG)

  • An ambulatory EEG (AEEG)

  • A PET scan

  • Blood tests

  • Functional magnetic resonance imaging (FMRI scan)

  • Single-photon emission computed tomography (SPECT scan)

To be thorough, many doctors may suggest a combination of these tests, and some might even require video recording to be added to your testing so that they can see how your body reacts when your heart or brain is experiencing unusual activity.

Once the cause and type of seizure are understood, your doctor will determine if any treatment is needed.

Many seizures are one-time events that result from other conditions unrelated to epilepsy, which your doctor will likely be able to address.

Can all doctors diagnose and treat seizures?

Generally speaking, your primary care doctor should be the first step towards diagnosing and getting treatment. In many cases where the condition is not epilepsy, they’re usually capable of diagnosing the problem with their own treatment and expertise.

If, however, they’re unable to reach a conclusion or suspect that you have epilepsy, they will most likely refer you to a neurologist.

Neurologists specialise in disorders of the brain and will be much better able to provide treatment if your primary doctor cannot. You may even be referred to an epileptologist, a neurologist who specialises in epilepsy, if that’s what your doctor suspects you have.

Treatment and management

Once diagnosed with epilepsy, the goal becomes trying to prevent and minimise seizures and their effects as well as possible. Epilepsy is a serious condition, but there are effective methods for treating and managing the condition.

Initially, epilepsy treatment begins with medication designed to control the seizures. When successful, these medications can reduce the frequency of seizures and minimise their effects in about 70% of people.

Diet and therapy may also be recommended for additional support. In severe cases, your neurologist may consider surgery. Together, you’ll discuss if it’s the right choice based on your medical history and individual needs.

Be prepared

If you’re a concerned friend, family member or caregiver of someone who is experiencing seizures, the best thing you can do is to be aware of what to do if they have one near you.

Here’s what to do if someone is having a seizure:

  • Time the seizure — How long the seizure lasts will determine whether or not you need to call an ambulance
  • Cushion their head — Head injuries are common during seizures especially when there are hard floors or objects that can cause harm
  • Roll them onto recovery position — To prevent choking, roll them onto their side if they have something in their mouth or after they stop moving
  • Stay with them until the seizure stops — They may be confused or disoriented afterwards. Help them remain calm and safe

Learning how to provide seizure first aid is simple and in most cases you will not have to call an ambulance.

Learn about how we help doctors and neurologists — visit our website today to learn more about epilepsy, seizures, and how you can manage them.