Understanding the Different Seizure Types
Seizures are complex neurological events that can vary significantly in their presentation and impact. As a cornerstone of epilepsy diagnosis and management, seizure classification helps healthcare professionals identify the type of seizure a person experiences, which is crucial for effective treatment.
Seizures can be classified as either focal or generalised, depending on where and how the abnormal brain activity originates.
Generalised seizures are a type of seizure that involves both sides of the brain from the onset. Unlike focal seizures, which originate in a specific area, generalised seizures affect the entire brain, leading to widespread symptoms.
Focal Seizures – stemming from activity in a specific area of the brain – are further divided into two types:
Focal Seizures Without Loss of Consciousness
These seizures can manifest through various symptoms, including motor symptoms like jerking movements or twitching in one part of the body. They may also involve sensory changes, such as unusual sensations, altered perceptions of taste, smell or sound, as well as autonomic symptoms like changes in heart rate, sweating, or nausea. Additionally, individuals might experience déjà vu, hallucinations, or sudden, intense emotions.
Focal Seizures With Impaired Awareness
In this type, the person may experience altered consciousness, appearing confused, dazed, or unresponsive—often staring into space. They may not have any memory of the event afterward. Symptoms can include repetitive movements, such as chewing, blinking, or rubbing hands, along with unusual, uncoordinated behaviours.
Types of focal seizures
Temporal lobe seizures: Begin in the areas of the brain responsible for processing process emotions and contributing to our short-term memory.
Frontal lobe seizures: Begin in the part of the brain that controls movement, problem-solving, and emotional regulation.
Occipital lobe seizures: Begin in the area primarily responsible for processing visual information.
Generalised seizures affect both sides of the brain simultaneously, involve widespread brain activity and typically lead to a loss of consciousness or altered awareness. There are several types of generalised seizures, each with distinct characteristics.
Types of generalised seizures
Absence seizures: Usually occur in children and younger people who can appear to go ‘blank’ or stare into space for a few seconds, experiencing a brief loss of awareness. Might involve subtle movements like blinking, fluttering eyelids or lip-smacking. Can occur in clusters, happening frequently throughout the day.
Tonic seizures: The body becomes stiff and rigid, which can cause you to fall to the ground. Usually lasts for a few seconds to a minute and you’ll typically lose consciousness or have significantly impaired awareness.
Clonic seizures: Characterised by repetitive, rhythmic contractions and relaxations of muscles, usually around the neck, face and arms. These typically last for a few minutes and often involve a loss of consciousness.
Atonic seizures: Also known as ‘drop seizures’, these manifest as a sudden and brief loss of muscle tone, which can cause your head to drop or your whole body to collapse.
Myoclonic seizures: Can affect one part of the body or multiple areas simultaneously – usually the upper body, arms and legs – and are characterised by sudden, involuntary muscle jerks or twitches that last for a fraction of a second to a few seconds.
Tonic-clonic seizures: Once known as ‘grand mals’, these can cause muscles to become rigid and tense, make breathing irregular and involve rhythmic, jerking movements of the limbs and body. Impacts can include tongue biting and loss of bladder control.
Responding to a seizure
Seizures don’t usually require emergency medical attention, but there are situations when it’s needed. Call 000 if:
- Stipulated within the person’s Epilepsy Management Plan
- The seizure has exceeded 5 minutes
- They have been injured
- It occurred while in water
- They are having trouble breathing
- There is food, fluid or vomit in their mouth – which they could have inhaled
- They are unresponsive 5 minutes after the seizure ends.
To find out more about epilepsy and build confidence around responding to a seizure, check out our education and training options.
