Epilepsy Vs Seizures: Key Differences

Seizures are episodes of abnormal electrical activity in the brain that result in different symptoms. For example, some seizures cause a loss of muscle tone or awareness. Seizures may occur spontaneously or can be triggered. 

Epilepsy is a chronic health condition that is characterized by repeated seizure activity. However, not all seizures are linked to epilepsy. We will compare seizures with epilepsy and the main differences and similarities.

What are seizures?

In the brain, electrical signals travel through the nerve cells to relay important information. However, if these electrical signals are disrupted or altered, this can lead to a seizure. 

Seizures are often associated with convulsions—rapid and uncontrollable shaking of the body. While it's true that some seizures can cause this, other seizures can present with different symptoms, such as a loss of muscle tone or loss of awareness.

Hence, there are several types of seizures, and each one falls into a specific category. 

Types of seizures

Seizures are categorized based on where they originate in the brain and the symptoms they cause. Regardless of the type, a typical seizure can last up to two minutes. When a seizure lasts longer than five minutes, it is a medical emergency, and urgent help is required. 

Focal seizures

Focal seizures, known as partial or localized seizures, generally start in one part of the brain but may spread to other areas. 

When focal seizures spread, they are known as generalized seizures because they occur simultaneously in more than one region of the brain. The two halves of the brain are the left and right hemispheres, and focal seizures can occur in either.

You may also hear healthcare professionals divide the brain into lobes when discussing the location of a focal seizure. These include the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe.

Focal seizures affect a small part of the brain, and different symptoms can occur depending on which part they affect. 

Each of the lobes is linked to these symptoms:

• Frontal lobe: Somatosensory auras (auras that cause a sensation) related to sensations such as pain, touch, and pressure in the chest or abdomen

• Parietal lobe: Somatosensory auras that are more linked to feelings of tingling, pain, or numbness

• Occipital lobe: Visual auras, such as flashing lights or bright patterns

• Temporal lobe: Abdominal symptoms 

To define focal seizures further, they can be regarded as either simple or complex. The main difference between these types is that a person is more likely to retain awareness or consciousness with simple focal seizures. In contrast, complex focal seizures can result in a loss of awareness or consciousness. 

Additionally, complex focal seizures may start in one area of the brain and then travel to another. But simple focal seizures remain localized.

Generalized seizures

Generalized seizures can start in more than one region of the brain, such as the left and right hemispheres. There are several different types of these seizures, which include the following:

• Absent, which is characterized by absent staring and unresponsiveness

• Atonic, which is characterized by a sudden decrease in muscle tone, resulting in a limp or collapsed body or body part

• Myoclonic, which is characterized by increased muscle tone causing sudden movements, such as repetitive jolting motions

• Tonic, which is characterized by stiffened muscles, loss of consciousness, and eyes rolling back

• Clonic, which is characterized by muscles that flex in the elbows, legs, and neck

• Tonic-clonic, which is a combination of tonic and clonic seizures

Additionally, certain generalized seizures can be regarded as motor or non-motor. These terms refer to whether or not generalized seizures affect movement. Some generalized seizures do, while others do not.

Unknown seizures

Seizures that have an unknown cause or onset are classified as unknown seizures. In addition, these seizures can be classified as having motor or non-motor effects and may or may not cause a loss of consciousness.

Seizure symptoms

The symptoms of seizures vary between people because it depends on the type of seizure that is present. However, generally speaking, these are the broad range of symptoms that can happen during a seizure:

• Loss of consciousness or awareness

• Shaking, trembling, jerking motions

• Auras or a sensation or visual effect that occurs just before or during the seizure

• Repetitive movements, such as lip smacking

• Muscle contractions and spasms

• Fainting or collapsing

• Fatigue

• Loss of motor control

What causes seizures?

Seizures can be caused by the following:

• Serious head injuries

• Brain tumors

• Strokes

• Brain infections, such as encephalitis or meningitis

• Oxygen loss at birth

• Alzheimer's disease

Sometimes the cause of seizures remains unknown, but if you experience recurrent seizures, your doctor may diagnose you with epilepsy.

What is epilepsy?

Epilepsy is a neurological disorder that causes people to have frequent and recurring seizures. These seizures start when clusters of nerve cells or neurons have disrupted electrical signals in the brain.

As a result of this disruption, seizures occur along with symptoms such as a loss of muscle tone, muscle spasms, loss of consciousness, or strange sensations.

It is possible to have a seizure without being diagnosed with epilepsy. Experts¹ say that at least two unprovoked seizures are required before doctors consider diagnosing someone with epilepsy.

Types of epilepsy

Epilepsy is often classified based on the type of seizures that are present. For example, simple focal, complex focal, or generalized. It can also be classified based on the brain region in which the abnormal activity occurs.

The International Classification of Epilepsies and Epileptic Syndromes has listed these categories for epilepsy:

• Localization-related (local, focal, partial) epilepsies and syndromes

• Generalized epilepsies and syndromes

• Epilepsies and syndromes undetermined whether focal or generalized

The generalized epilepsies and syndromes category includes West syndrome and Lennox-Gastaut syndrome. Both conditions are related to epilepsy and are caused by genetic factors.

Epilepsy symptoms

The general symptoms of epilepsy are related to the effects of seizures. Therefore, the symptoms of epilepsy are essentially the same symptoms of seizures. However, some epilepsy conditions, such as West syndrome, may have additional symptoms. 

What causes epilepsy?

Epilepsy can also be caused by:

• Serious head injuries

• Brain tumors

• Strokes

• Brain infections, such as encephalitis or meningitis

• Oxygen loss at birth

However, in some cases, the cause is related to genetics or is unknown.

The lowdown

Overall, a seizure is caused by abnormal electrical activity in the brain. Different symptoms can present depending on where the electrical activity is disrupted in the brain. Epilepsy is a seizure condition; sometimes, patients are diagnosed with it when they frequently have recurring seizures.

However, it is possible to experience a seizure, even when you do not have epilepsy. That's because there is a range of factors that contribute to seizures. Therefore, if you or a loved one is experiencing frequent seizures, it's essential to seek medical advice to determine the cause or find treatment if necessary.

FAQs

What is the main difference between seizures and epilepsy?

Seizures are isolated episodes of abnormal electrical activity in the brain. Various factors can cause seizures, such as strokes, a lack of sleep, or a fever. Epilepsy, however, is a chronic neurologic disorder that regularly causes seizures.

Does epilepsy cause seizures?

Epilepsy is a neurological condition characterized by frequent seizures. In some cases, the cause of the seizures is known. However, in other cases, the cause is unknown.

How long do seizures last?

A typical seizure can last up to two minutes. Seizures that last longer than five minutes are medical emergencies and require urgent help.