9. Seizures and Epilepsy

What is a seizure?

A brief, excessive discharge of brain electrical activity that alters behavior.

What causes a seizure?

An imbalance favoring excitatory (glutamate) over inhibitory (GABA) signaling.

What is epilepsy?

A tendency to have recurrent unprovoked seizures.

What is required to diagnose epilepsy?

Two or more unprovoked seizures, or one with a high likelihood of recurrence.

What is the lifetime prevalence of seizures?

1 in 11 people.

What is the prevalence of epilepsy?

1 in 100 people.

At what ages is epilepsy onset most common?

Under age 10 and over age 65.

What neurotransmitters influence seizure risk?

GABA (inhibitory) and glutamate (excitatory).

What are potential causes of seizures?

CNS injury, drugs, metabolic disturbances, genetics.

What are the two main types of seizures?

Focal and generalized.

Where do focal seizures originate?

One specific area of the brain.

Where do generalized seizures originate?

Simultaneously across the whole brain.

What is a focal aware seizure?

A focal seizure with retained awareness.

What is a focal impaired awareness seizure?

A focal seizure with altered awareness.

What is a focal to bilateral tonic-clonic seizure?

A focal seizure that spreads to become generalized.

What are generalized motor seizures?

Generalized tonic-clonic or myoclonic seizures.

What are generalized non-motor seizures?

Absence seizures.

What is another name for absence seizures?

Petit mal seizures (old term).

What is an epilepsy syndrome?

A disorder defined by seizure type, EEG, age of onset, neurologic status, and prognosis.

What are the four key epilepsy syndromes to know?

Febrile seizures, West syndrome, childhood absence, and juvenile myoclonic epilepsy.

What are febrile seizures?

Generalized tonic-clonic seizures in children with high fever (>38°C).

What age range is typical for febrile seizures?

6 months to 5 years.

What is a simple febrile seizure?

Lasts <15 min, occurs once in 24 hours, no focal features.

What is a complex febrile seizure?

Lasts >15 min, occurs more than once in 24 hours, or has focal features.

What percent of children experience febrile seizures?

2–5%.

When is recurrence of febrile seizures more likely?

If the first seizure occurs before age 1.

What increases the risk of epilepsy after febrile seizure?

Complex febrile seizures, abnormal development, and family history of afebrile seizures.

What percent of children with febrile seizures later develop epilepsy?

Up to 10%.

What are infantile spasms?

Generalized seizures with trunk flexion, arm extension, and leg drawing up.

What age does West syndrome typically begin?

3–9 months.

What is the EEG finding in West syndrome?

Hypsarrhythmia — a chaotic, high-voltage pattern.

What are causes of West syndrome?

CNS malformations, genetic syndromes (e.g., Tuberous Sclerosis), CNS injury/infection.

What is the treatment for West syndrome?

ACTH.

What age range does childhood absence epilepsy typically affect?

4–8 years.

What is the clinical presentation of absence seizures?

Sudden loss and return of responsiveness without aura or postictal state.

What is the typical EEG finding in absence seizures?

3 Hz spike-and-wave pattern.

What is the preferred treatment for childhood absence epilepsy?

Ethosuximide.

What are symptoms of JME?

Myoclonic jerks, tonic-clonic seizures, and sometimes absence seizures.

When do JME seizures typically begin?

Puberty or late teens/early adulthood.

When do JME seizures commonly occur?

In the early morning after waking.

Is intelligence normal in JME?

Yes.

What is the EEG finding in JME?

3–6 Hz spike-and-wave, often with polyspikes.

Is neuroimaging normal in JME?

Yes.

What triggers JME seizures?

Sleep deprivation and alcohol.

Is treatment for JME lifelong?

Yes.

What is the first step in epilepsy treatment?

Precise diagnosis of seizure type and underlying cause.

What is the goal of epilepsy treatment?

Control seizures and address underlying pathology.

What is the first-line treatment for most epilepsy cases?

Anti-epileptic drugs (AEDs).

What factors influence AED selection?

Seizure type, patient age, sex, comorbidities, and other medications.

Why is shared decision-making important in epilepsy care?

It improves treatment adherence.

What is monotherapy in epilepsy?

Starting treatment with a single AED.

What is done if the first AED fails or isn’t tolerated?

Switch drugs or add a second AED.

What is a lobectomy in epilepsy?

Surgical removal of the seizure focus area in the brain.

What is the success rate of lobectomy for seizure freedom?

50–80%.

What is a corpus callosotomy?

Surgical separation of the cerebral hemispheres to prevent seizure spread.

When is hemispherectomy used?

In very rare, severe epilepsy cases.

What is VNS in epilepsy treatment?

Vagus nerve stimulation.

What is RNS in epilepsy treatment?

Responsive neurostimulation—detects and interrupts seizures in real time.

What is DBS in epilepsy treatment?

Deep brain stimulation of thalamic nuclei for focal or generalized seizures.

What thalamic targets are used for DBS in epilepsy?

Anterior nucleus (focal seizures), central median nucleus (generalized seizures).