Introductory Edition 2: Epilepsy Symptoms, Seizures, and Triggers Explained

In the first edition, we explored some foundational aspects of epilepsy, including its definition, causes, methods of diagnosis, types, and treatments. However, one crucial element we didn’t delve into was the variety of symptoms associated with this condition.

This brings us to an important point—one of the many misconceptions surrounding epilepsy: the belief that all individuals with epilepsy experience seizures characterized by loss of consciousness and convulsions.

Just to clarify, I too held this misconception, largely influenced by portrayals in the media and widespread assumptions. However, I quickly learned that this narrow understanding can be detrimental. Seizures manifest in numerous ways, and failing to recognize the diversity of seizure types can lead to misunderstandings and inadequate support for those living with epilepsy.

In this edition, we'll revisit the two major classifications of epilepsy—focal and generalized—and delve into the specific seizures and symptoms associated with each. So grab your pen and paper, and get ready to deepen your understanding of the diverse epilepsy symptoms!

Key terms:

Before we begin, it would be useful to introduce some basic definitions for some terms that we will encounter throughout:

• Myo- : muscle
• Clonic: repeated jerking
• Tonic: increase in muscle tone (i.e. muscle stiffness)
• Atonic: decrease in muscle tone (i.e. muscles become limp)

Generalised epilepsy:

Generalised epilepsy consists of 2 main types of seizures:

1) Generalised Motor Seizures: Involves the change in muscle activity as seen in the following seizures:

• Myoclonic seizures: sudden body jerks or an increase in muscle tone as if someone had been jolted with electricity.
• Tonic - Clonic (Grand mal) seizures: when an initial tonic (stiffness) phase is followed by a clonic (repeated, uncontrolled jerking of the limbs) phase. During the 'tonic' phase, patient also lose consciousness and could fall to the floor. In the 'clonic' phase, patients may lose control of their bladder, have difficulty breathing, or may bite their tongue or the inside of their cheek. This is most likely the typical epileptic fit everyone typically thinks about as mentioned in the misconception earlier.
• Atonic seizures: decrease in muscle tone, causing the body to be limp, or even collapse.

2) Generalised Non-motor (Petit Mal) seizures:

They are usually also referred to as 'Absence Seizures', which involve staring into space, and with a pause in activity, or a repetition in movements, such as lip-smacking for around 15 seconds or less. The individual may not remember what happened during the seizure, however their normal state of alertness is regained immediately after.

This seizure could easily be mistaken for daydreaming.

Focal Epilepsy

Focal epilepsy consists of 4 main types of seizures:

1) Focal awareness (simple partial) seizures: Patient is fully aware of what is occurring during a seizure, even if they are unable to move or respond.

Individuals experiencing focal awareness seizures can also experience an 'aura' - an unusual feeling, feeling of impending doom, fear or euphoria or feeling of déjà vu - as a warning that they will experience another type of seizure (e.g. tonic clonic seizures)

Other less obvious symptoms associated with auras can include changes in taste, smell, vision, twitchiness, stiffness or tingling in parts of the body.

2) Focal impaired awareness (complex partial) seizures: Lack of awareness or memory of the seizure. This can include movements such as moving the limbs, making random noises, smacking the lips. Individuals will not be able to respond to anyone during the seizure.

3) Focal Motor Seizures: involve random muscle activity, such as twitching, spasms, stiffness, loss of muscle tone, or other (repeated) movements such as rubbing hands, and walking around.

4) Focal Non-motor Seizures: no muscle related symptoms such as random movements/twitching, however there is a change in a patient’s feelings and thoughts, causing strange feelings, a racing heart, waves of heat or cold.

Focal Seizure Symptoms by Brain Area

As we have covered, focal epilepsy and its respective seizures are a little more lengthy and complicated. But how do we know which individuals experience which types of seizures?

The type of focal seizure experienced depends on which region (or lobe) of the brain is affected (i.e. which lobe of the brain experiences the abnormal bursts of electrical activity) which can lead to a variety of symptoms across different patients. Sometimes a seizure can also spread to affect other regions of the brain.

A Brain consists of 2 Hemispheres (left and right hemisphere). Each hemisphere consists of 4 lobes including:

• Frontal lobes: important in regulating personality, emotions, concentration and body-movements.

Seizures in the frontal lobe mainly occur during sleep, and usually last short periods of time.

They can include symptoms such as: rocking movement, unusual movements (e.g. stretching one arm while bending the other), screaming, unintentionally urinating, jerking of muscles which may spread to other areas of the body.

• Occipital lobes: responsible for processing visual information.

Seizures beginning in the Occipital lobes can spread to other areas of the brain.

Symptoms include: seeing flashing lights, patterns or complex images, not being able to see anything at all (or as well as usual), uncontrolled eye movements, repeated blinking.

• Temporal lobes: responsible for memory, hearing and understanding language

Seizures staring in the temporal lobe are usually focal impaired awareness seizures.

Symptoms include those of Focal impaired awareness seizures, in addition to: feelings of déjà vu, rising feeling in the stomach or hearing non-existent sounds.

Patients may feel confused after a temporal lobe seizure and may experience speech difficulties for a short period of time.

• Parietal lobes: important in spatial awareness, language processing, and interpreting touch, vision, and hearing signals.

Symptoms of seizures in the parietal lobe include: numbness, electric shock sensations, feelings of floating, sensations of body parts shrinking, enlarging, or disappearing, trouble with language, reading, writing, or simple math, distorted or imaginary visual experiences.

Summary

Here is a summary for the content that we have covered so far:

Status Epilepticus

Status epilepticus is a life- threatening medical emergency, where any seizure lasts for a long period of time, or when an individual has multiple seizures, one after the other, without no regain of consciousness in between.

This can be classified into Convulsive and Non convulsive Status Epilepticus:

• Convulsive: a tonic-clonic seizure lasting more than 5 minutes, or a series of tonic-clonic seizures with no regain of consciousness in between.

If convulsive Status epilepticus lasts 30 minutes or more, it can cause permanent brain damage or even death.

• Non Convulsive: Involving other seizure types, such as absence seizures or focal impaired awareness seizures.

Seizure Triggers

Now that we have learnt the different types of Epileptic seizures and their symptoms, it is important to understand which factors can trigger an individual to have a seizure.

This includes the following:

• Stress
• Lack of sleep
• Alcohol consumption
• Recreational drugs
• Some medication
• Menstrual Cycle and hormonal changes
• Flashing lights (particularly for individuals with Photosensitive epilepsy)

Takeaway

In this edition, we've explored the different types of generalised and focal seizures, along with their respective symptoms. We’ve examined how seizures in various brain lobes can lead to diverse symptoms and delved into Status Epilepticus and common seizure triggers.

Most importantly though, we have addressed a key misconception about epilepsy: the belief that all individuals with epilepsy experience seizures characterized by loss of consciousness and convulsions.

Yes, some individuals with epilepsy indeed experience loss of consciousness and convulsions, however this isn't the case for all patients. Epileptic seizures vary from convulsions, to limpness, to absence seizures, to awareness and impaired awareness seizures.

Understanding this diversity is essential for better awareness and support for those with epilepsy. Each individual’s experience can be unique, and recognizing this helps in providing appropriate care and support.

References:

Epilepsy action (2022). Focal seizures | Epilepsy Action. [online] www.epilepsy.org.uk. Available at: https://www.epilepsy.org.uk/info/seizures/focal-seizures [Accessed 23 Aug. 2024].

Epilepsy Action. (2023). Status epilepticus and emergency treatment. [online] Available at: https://www.epilepsy.org.uk/info/first-aid/emergency-treatment-seizures-last-long-time [Accessed 22 Aug. 2024].

John Hopkins Medicine (n.d.). Generalized Seizures. [online] Available at: https://www.hopkinsmedicine.org/health/conditions-and-diseases/epilepsy/generalized-seizures#:~:text=Generalized%20seizures%20include%20absence%2C%20atonic [Accessed 22 Aug. 2024].

NHS (2020). Symptoms - Epilepsy. [online] NHS. Available at: https://www.nhs.uk/conditions/epilepsy/symptoms/ [Accessed 22 Aug. 2024].