This factsheet has been compiled with information supplied by Young Epilepsy and explains the different types of epilepsy seizure that can occur with the condition.

Everyone’s epilepsy is unique to them. Classifying which seizure type(s) your child has experienced is important for managing the condition. Seizure types fall into two main categories – generalised seizures and focal (partial) seizures.

Generalised seizures

Generalised seizures occur when both sides (hemispheres) of the brain are affected by abnormal electrical activity and the child becomes unconscious. Examples of generalised seizures include:

Tonic seizures

These used to be known as ‘grand mal’ seizures. It usually starts with a cry and a loss of consciousness resulting in the child falling to the ground. A ‘tonic’ or stiff phase then leads to a ‘clonic’ or jerking phase. Finally, there may be confusion, often followed by sleep. In some cases, the seizure can result in incontinence.

Atonic seizures

Atonic is the opposite of tonic. During an atonic seizure, there will be a loss of all muscle tone, which causes the child to suddenly flop forward and fall. These are sometimes referred to as ‘drop attacks’ and can appear quite dramatic as the child falls heavily to the ground. Although the seizure is very brief (less than 15 seconds) and the child can often continue with activities quite quickly following the seizure, there is a significant risk of facial or head injuries. Protective headwear may be recommended to prevent injury if these seizures occur frequently.

Tonic-clonic seizures

Traditionally, these seizures were referred to as ‘grand mal’ which means ‘great illness’. Now, however, the name tonic-clonic goes some way to describe the actual physical symptoms that occur during the seizure. This is probably the type of seizure most people think of when they hear about epilepsy. Like all generalised seizures, they are caused by electrical discharges firing simultaneously throughout the brain. This type of seizure has two phases, the tonic phase followed by the clonic phase:

Tonic phase:

The child becomes rigid as their muscles contract. They may let out a cry as air is pushed out of their lungs, but they are not in any pain. Consciousness is lost and they will usually fall to the floor if standing, often backwards. Breathing may become laboured or stop momentarily. As their breathing pattern changes they may lose colour and the skin around the mouth may appear blue, as there is less oxygen than usual in the lungs.

Clonic phase:

The muscles then relax and tighten rhythmically, causing the body and limbs to jerk or convulse. As the seizure comes to an end, the rhythmical jerking stops and the muscles relax. The child will regain consciousness but is often confused and it can take some time for them to return to normal. They may also have been incontinent or bitten their tongue. Often the child will be exhausted and need to sleep.

Myoclonic seizures

‘Myo’ means muscle and ‘clonic’ means jerk. When myoclonic seizures occur, the muscles contract rapidly rather as if the child has had a very brief shock-like contraction. Myoclonic seizures usually occur shortly after waking (sometimes known as a ‘messy breakfast’) or before going to bed when the child is tired. During myoclonic seizures, there is a loss of consciousness but, as these seizures tend to last less than a second, it is hardly noticeable. Sometimes myoclonic seizures occur in clusters.

Absence seizures (typical)

Absence seizures used to be referred to as ‘petit mal’ seizures. They often begin in childhood and do not usually continue into adulthood. They may occur many times a day and provoke a brief ‘trance-like’ state. The child will stare blankly into space and be unresponsive usually for 5 to 10 seconds.

Recovery is immediate and the child continues what they were doing, so the seizure may go unnoticed. Their failure to respond, when they are spoken to, often results in the child being told off in school for not paying attention or for daydreaming. The child is unaware of their seizure afterwards. This seizure type is associated with characteristic changes in EEG (electroencephalogram) recordings.

Absence seizures (atypical)

These atypical seizures do not start or finish as abruptly as typical absence seizures. The seizures usually last longer and may have additional features, such as changes in muscle tone. These changes may result in small movements, such as a slight nodding of the head or a chewing action and the child may continue to respond to their surroundings. These atypical absence seizures are often associated with other seizure types and/or learning disabilities.

Focal seizures

Focal seizures are the result of intense electrical activity occurring in an area on one side of the brain, namely the ‘focus’ of the seizure. These seizures are described according to their manifestations, particularly whether they cause changes in movement (motor symptoms) or sensation (sensory symptoms) for the child. What the seizure looks like depends on where in the brain it comes from and what function that area is responsible for. There may be some impairment of consciousness with these seizures, although sometimes the child may be fully aware throughout. Focal seizures can spread to affect the whole brain, resulting in a generalised seizure known as a ‘bilateral convulsive seizure’.

Temporal lobe epilepsy

This is the most common type of epilepsy that causes focal seizures. It can start in children of any age. The temporal lobes are primarily responsible for smell and hearing, language and memory.

Seizure activity focused in this area of the brain, means the child may experience a sudden strange mix of feelings, emotions or thoughts they might find difficult to describe. These may include a feeling of déjà vu, butterflies in the stomach, nausea, odd smells or tastes. These sensations may occur alone or may be a precursor (aura) to further seizure activity that impairs consciousness. These complex seizures may cause unusual movements, such as lip smacking or finger fumbling (uncontrollable finger movements). They may also develop into tonic-clonic seizures and tend to be followed by confusion.

Frontal lobe epilepsy

The frontal lobes are a large area of the brain responsible for emotional behaviour, personality, planning, problem-solving and some high level cognitive functions, as well as the control of movement.

Seizures that arise from this part of the brain will vary in nature depending on which part of the frontal lobe is involved. They will often occur in clusters that start and end abruptly. They may produce weakness in certain muscles, including those used in speech, or cause sudden movements in the limbs, such as the flinging out of an arm. Seizures usually occur during sleep and can present in very strange and dramatic ways, including head turning, grimacing, thrashing around or cycling movements of the legs.

Occipital lobe epilepsy

This lobe, in the posterior part of the brain, is responsible for processing visual information and recognising shapes and colours. Occipital lobe seizures are less common than other focal seizures. They usually present with vision-related symptoms, such as rapid eye blinking, seeing patterns, flashing lights or colours. Seizures can spread to the temporal or frontal lobes. When this happens the characteristics of the seizure change, often making it hard to recognise as occipital lobe epilepsy.

Parietal lobe epilepsy

The parietal lobes are responsible for interpreting sensory information and spatial orientation as well as artistic and musical appreciation. Seizures arising from this part of the brain usually result in strange sensations and are often referred to as sensory seizures. These may present as tingling or warmness often occurring down one side of the body. There may be areas of numbness or an unusual feeling of a difference in the size of the limbs.

Febrile seizures

Febrile seizures (also known as febrile convulsions) may occur in children between the ages of 6 months and 6 years. They are a relatively common childhood condition. A child may have a febrile seizure when they have a high temperature, however, a diagnosis of epilepsy is not usually made in these children, as they are often isolated events with a known cause. Most febrile seizures are harmless and don’t pose a threat to your child’s health. An estimated 1 in 20 children will have at least one febrile seizure at some point.

It is estimated that children with a history of simple febrile seizures have a 1 in 50 chance of developing epilepsy in later life. Children with a history of complex febrile seizures have a 1 in 20 chance of developing epilepsy in later life.

Useful Links

Young Epilepsy

Offers support and information, as well as lots of epilepsy resources
www.youngepilepsy.org.uk
Helpline: 01342 831342
Email: helpline@youngepilepsy.org.uk

Want to find out more about epilepsy and what it is? Check out our article Purple Day – epilepsy awareness