Seizure Disorders: Seizure Types, Initiating & Discontinuing Therapy

What is a seizure physiologically?

Abnormally rapid and/or repetitive firing of neurons

At what duration does seizure activity become a medical emergency?

>5 minutes

What determines the symptoms experienced during a seizure?

The location of the neurons with abnormal electrical activity

What is the key distinction between a seizure and epilepsy?

- Seizure = one abnormal electrical event

- Epilepsy = involves a predisposition to recurrent unprovoked seizures

Do all patients who have a seizure have epilepsy?

No

What are the two major ways a patient can meet the lecture definition of epilepsy?

- ≥2 unprovoked seizures, OR

- 1 unprovoked seizure with ≥60% predicted risk of recurrence

How far apart must two unprovoked seizures occur to meet the epilepsy definition?

At least 24 hours apart

If a seizure has a reversible cause, is long-term antiseizure treatment always necessary?

No, treatment may not be necessary

What are potential seizure risk factors?

- Premature birth

- Low birth weight

- Perinatal injury

- History of febrile seizures

- Ethanol withdrawal seizures

- Family History

What are potential triggers for a seizure?

- Hormone changes (pregnant/menopause)

- Hyperventilation

- Medications

- Photostimulation

- Sensory Stimuli

- Sleep deprivation

- Stress

What are the four phases surrounding a seizure event?

1. Prodrome/aura

2. Ictal event

3. Postictal phase

4. Interictal phase

Which phase is the actual seizure?

Ictal phase

Which phase occurs after the seizure?

Postictal phase

Which phase refers to the period between seizures?

Interictal phase

What are possible symptoms of an aura?

- Dizziness

- Nausea

- Panic/fear

- Vertigo

- Déjà vu

- Abnormal smell

- Taste, vision, or feeling

What three factors are used to classify seizures?

Origin, Awareness, Features

Where does abnormal electrical activity originate in a focal-onset seizure?

One cerebral hemisphere

Where does abnormal electrical activity originate in a generalized-onset seizure?

Both hemispheres

What are the two major types of generalized-onset seizures?

Motor and non-motor

What are the four broad combinations of focal seizure classification?

- Focal aware motor

- Focal aware non-motor

- Focal impaired awareness motor

- Focal impaired awareness non-motor

Clonic vs. myoclonic activity: what is the key difference?

- Clonic = sustained rhythmic jerking

- Myoclonic = sudden, brief, arrhythmic/shock-like twitching

How do the main generalized motor seizures differ?

Atonic = loss of tone

Clonic = sustained rhythmic jerking

Myoclonic = sudden, brief, shock-like/arrhythmic jerks

Tonic-clonic = stiffening followed by rhythmic jerking

What does a generalized non-motor (absence) seizure look like?

- Staring and unresponsiveness with little to no muscle involvement

- May have blinking, eyelid twitching, chewing, or hand movements.

What findings favor starting antiseizure treatment?

- Irreversible precipitating event

- Epilepsy syndrome diagnosis

- Abnormal neurological examination or EEG

- ≥2 unprovoked seizures

- 1 seizure with >60% recurrence risk

- Status epilepticus as initial seizure

- Family history

- CNS lesion or damage

How many unprovoked seizures generally support treatment?

Two or more

What finding on neurologic testing may favor treatment initiation?

Abnormal neurological exam or EEG

What circumstances support considering no antiseizure treatment?

- Identifiable transient cause

- Normal neurologic exam and EEG

- Normal IQ/developmental history

- Only one seizure with low recurrence risk

Before labeling a medication ineffective, what patient behavior should be assessed?

Adherence

What characteristics are associated with successful antiseizure medication discontinuation?

- Single seizure type

- Normal neurological examination

- Normal EEG

How long should a patient generally be seizure-free before considering ASM discontinuation?

At least 2 years

What criteria favor ASM discontinuation?

- Seizure-free ≥2 years

- Single seizure type

- Normal neurologic exam

- Normalized EEG

- Normal IQ

If a patient takes multiple antiseizure medications, which agent may be discontinued first?

The medication least appropriate for the patient's seizure type

What adverse-effect consideration can determine which ASM should be stopped first?

Discontinue the agent most likely responsible for the most distressing adverse effects

Which medication may also be considered for discontinuation first in a multi-drug regimen?

The last agent added

Should multiple antiseizure medications be tapered simultaneously?

No