Seizures & Syndromes
Seizures and epilepsy syndromes can look very different from person to person. Understanding seizure types and identifying a specific epilepsy syndrome can help guide treatment decisions, safety planning, and long-term care. Every individual’s experience with epilepsy is unique.
What Is a Seizure?
A seizure is a sudden, temporary disruption of electrical activity in the brain. The brain communicates through electrical signals that allow nerve cells to work together. When that activity becomes excessive, abnormal, or unusually synchronized, it can interrupt normal brain function.
Depending on where the seizure begins and how it spreads, it may affect movement, awareness, sensation, speech, memory, behaviour, emotions, or breathing patterns. Some seizures last only seconds; others last minutes.
Not all seizures involve convulsions. Many seizures are subtle and may look like staring, confusion, brief unresponsiveness, or unusual repetitive movements.
How Seizures Are Classified
Seizures are commonly classified by where they start in the brain and whether awareness is affected. The two main categories are focal seizures and generalized seizures.
Focal Seizures
Focal seizures begin in one area of the brain. Symptoms depend on which brain region is involved. Focal seizures may stay in one area or spread.
- Focal aware seizures: Awareness remains intact. The person may be able to describe what happened.
- Focal impaired awareness seizures: Awareness is altered. The person may be confused or not respond normally.
- Some focal seizures can spread and become bilateral tonic-clonic seizures.
Generalized Seizures
Generalized seizures involve both sides of the brain from the start and typically affect awareness. There are several generalized seizure types, each with a distinct presentation.
- Tonic-clonic: Stiffening followed by rhythmic jerking
- Absence: Brief staring spells with a pause in activity
- Myoclonic: Sudden brief muscle jerks
- Tonic: Sudden stiffening
- Atonic: Sudden loss of muscle tone (drop attacks)
Possible Seizure Symptoms
Seizure symptoms can vary widely. Two people with the same seizure type may still experience seizures differently. Examples of seizure symptoms include:
- Sudden confusion or inability to respond
- Staring or “blank” episodes
- Jerking or stiffening movements
- Repetitive movements (lip smacking, picking at clothing)
- Sudden falls or loss of balance
- Unusual sensations (tingling, visual changes)
- Unusual smells or tastes
- Emotional changes (fear, déjà vu)
- Temporary difficulty speaking
- Fatigue or confusion after the seizure (postictal period)
What Is an Epilepsy Syndrome?
An epilepsy syndrome is more than a seizure type. It is a defined pattern of features that occur together. Identifying a syndrome can help guide treatment choices and provide a clearer understanding of what to expect over time.
Epilepsy syndromes may include:
- Age of onset
- Type(s) of seizures
- Typical seizure timing (sleep-related, morning, etc.)
- Triggers
- EEG patterns
- Genetic factors
- Response to medication
- Developmental, learning, or behavioural features
Different Types of Epilepsy Syndromes
Epilepsy syndromes can be grouped in different ways. Some are age-related and may improve over time, some are genetic, and some are related to brain structure or injury. Others are more complex and may require specialized treatment and ongoing support.
Self-Limited (Age-Related) Epilepsies
These syndromes often begin in childhood and may resolve as a child grows older. Seizures may be infrequent or follow a predictable pattern.
- Childhood Absence Epilepsy
- Self-limited epilepsy with centrotemporal spikes (often called “benign rolandic epilepsy”)
Genetic Epilepsies
Genetic epilepsies may be inherited or occur due to new (spontaneous) genetic changes. They can begin at different ages and may involve generalized or focal seizures.
- Juvenile Myoclonic Epilepsy (JME)
- Genetic generalized epilepsies
- Dravet syndrome (genetic epilepsy beginning in infancy)
Structural or Focal Epilepsies
These epilepsies are associated with structural changes in the brain, such as scarring, cortical dysplasia, stroke, tumours, or brain injury. Seizures usually begin in a specific area.
- Temporal lobe epilepsy
- Frontal lobe epilepsy
Developmental & Epileptic Encephalopathies
These syndromes may involve frequent seizures and can affect learning, development, and behaviour. They often require specialized care and a multidisciplinary approach.
- Lennox-Gastaut syndrome
- Infantile spasms (West syndrome)
- Dravet syndrome
Reflex Epilepsies
Seizures are triggered by specific stimuli such as flashing lights, patterns, reading, or other specific inputs. Not everyone with epilepsy is photosensitive, but for those who are, trigger management is important.
- Photosensitive epilepsy
Unknown or Unclassified Syndromes
Sometimes seizures do not clearly fit a defined syndrome right away. Diagnosis may evolve over time as more information is gathered through observation, EEG, imaging, and response to treatment.
Examples of Epilepsy Syndromes
Below are examples of syndromes that people may hear about after diagnosis. A healthcare provider may use information such as seizure description, EEG results, age of onset, and medical history to identify a syndrome.
Childhood Absence Epilepsy
Typically begins between ages 4 and 10. Seizures may look like brief staring spells with a pause in activity. These can happen multiple times per day. Many children respond well to treatment, and some outgrow seizures.
Juvenile Myoclonic Epilepsy (JME)
Often begins in adolescence. Myoclonic jerks frequently occur shortly after waking. Some individuals may also have tonic-clonic or absence seizures. JME often responds well to medication.
Temporal Lobe Epilepsy
A common focal epilepsy originating in the temporal lobe. Seizures may include déjà vu, sudden fear, unusual sensations, or impaired awareness. Some people experience memory or emotional changes around seizures.
Lennox-Gastaut Syndrome
A severe childhood-onset epilepsy involving multiple seizure types (often including atonic seizures), characteristic EEG findings, and developmental challenges. Treatment often requires specialized care.
Infantile Spasms (West Syndrome)
Typically begins in infancy. Spasms may occur in clusters and can involve sudden bending or stiffening movements. Early diagnosis and treatment are important.
Dravet Syndrome
A rare genetic epilepsy beginning in infancy. Seizures can be prolonged and may be triggered by fever or illness. Dravet syndrome typically requires specialized treatment approaches and long-term support.
Why Seizures and Syndromes Affect People Differently
Epilepsy is not the same for everyone. The impact can vary depending on seizure type, frequency, syndrome, underlying cause, and overall health. Some people achieve complete seizure control with medication, while others may require additional therapies and supports.
Factors That Can Influence Experience
- Underlying cause (genetic, structural, unknown)
- Age of onset
- Seizure frequency and duration
- Triggers and daily routines (sleep, stress, illness)
- Response to medication
Possible Areas of Impact
- Learning and attention
- Memory and processing speed
- Emotional well-being
- Independence and safety planning
- School, work, and social life
With appropriate medical care, education, and community supports, many individuals living with epilepsy lead full and active lives.