Epilepsy 101: what are the different types of epilepsy seizures?

After previously covering a very generic overview into epilepsy – what it is, its different types, methods of diagnosis and treatment, it would be a good idea to really delve deeper into the different types of seizures. Are they just convulsions, shaking and losing consciousness? Or is there more to it? Read more to find out!

But before we begin, it is important to cover some key terms and prefixes, to help us with understanding what the different types of seizures are: 

• Myo-: muscle

• Clonic: repeated jerking

• Tonic: muscle stiffness

• Atonic: muscles become limp

• Motor: movement

  
  

From our previous article, we know that the two main types of epilepsy are generalised and focal epilepsy. Each type of epilepsy has different types of seizures associated with it. 

Generalised epilepsy – it consists of 2 main types of seizures (motor and non-motor seizures): 

1) Generalised Motor Seizures: Involves changes in muscle activity, where they either move abnormally, or don’t move at all. This includes:

• Myoclonic seizures: sudden body jerks (especially the hands or the legs) as if someone had been jolted with electricity.

• Tonic - Clonic (Grand mal) seizures: This seizure has 2 main phases – a tonic and clonic stage:- Initial tonic (stiffness) phase is followed by a clonic (repeated, uncontrolled jerking of the limbs) phase. During the 'tonic' phase, the person may become unconscious and fall to the floor. In the 'clonic' phase, the person might struggle to breathe or uncontrollably bite their tongue. This is probably the ‘typical’ seizure everyone thinks of when they hear about epilepsy!

• Atonic seizures: The muscles become limp, and the person might even collapse.

2) Generalised non-motor seizures:

They are usually also referred to as 'absence seizures', and they don’t include any changes in muscle activity. Instead, the person might stare into space, and might have 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. People might easily confuse this type of seizure with daydreaming!

Focal epilepsy- This is split into 4 main types based on whether the person is aware of their seizure, and if there are any changes in muscle activity involved: 

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

Some people might experience an "aura" as a warning before this seizure. This could feel like a strange sensation, fear, euphoria, a sense of déjà vu, feeling that something bad is about to happen, visual changes or even tingling or stiffness in their body.

2) Focal impaired awareness seizures: The person isn’t aware of their seizure, nor can they remember having it, and can’t respond to anyone during the seizure. The seizure can include movements such as moving their hands and legs or making random noises.

3) Focal Motor Seizures: involves random muscle activity, such as twitching, stiffness, limpness, or other movements such as rubbing hands, lip-smacking and walking around.

4) Focal Non-motor Seizures: no muscle movements or stiffness (as this is a non-motor seizure), but there is a change in a patient’s feelings and thoughts, causing strange feelings, a racing heart, and waves of heat or cold.

Now that we’ve covered the key seizures, what triggers epilepsy seizures, causing those lights in the city (which in this case, is our brain) to start flickering or shut completely?

There are many different causes, and they vary from one person to another. They could include: 

• Stress

• Lack of sleep

• Drinking alcohol 

• Consuming illegal drugs

• Not taking your anti-seizure medication (ASMs)

• Some types of medication

• Menstrual Cycle and hormonal changes

• Flashing lights (for individuals with photosensitive epilepsy)

  
  

Photosensitive epilepsy is epilepsy that is triggered by flashing of lights, causing seizures such as myoclonic seizures.

It is interesting to see how many people hold the misconception that seizures are mainly uncontrolled jerking and losing consciousness, when in fact there’s a huge variety of seizure! It is important that we know what different seizures look like, so we could help these individuals appropriately. Don’t be afraid to read further about epilepsy and seizures, and how to help people out there! 

Written by Hanin Salem

Related article: Epilepsy 101 (overview)

REFERENCES

Dhanyamraju, S. (2019). What is a Seizure? - Lone Star Neurology. [online] Lone Star Neurology. Available at: https://lonestarneurology.net/seizures/seizures/. [Accessed 19 Dec. 2024].

Ditki medical & biological sciences. (n.d.). Neurological System Glossary: Tonic-Clonic Seizure. [online] Available at: https://ditki.com/course/neurological-system/glossary/eeg-findings/tonic-clonic-seizure.  [Accessed 19 Dec. 2024].

Epilepsy action (2022). Focal seizures | Epilepsy Action. [online] www.epilepsy.org.uk. Available at: https://www.epilepsy.org.uk/info/seizures/focal-seizures [Accessed 18 Dec. 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 17 Dec.2024].

NHS (2020). Symptoms - Epilepsy. [online] NHS. Available at: https://www.nhs.uk/conditions/epilepsy/symptoms/ [Accessed 17 Dec. 2024].