Epilepsy and Seizure Disorders
Seizure Fundamentals
Core concept
A seizure is a transient event caused by abnormal, excessive, synchronized neuronal activity. Epilepsy refers to a tendency for recurrent unprovoked seizures.
Clinical distinction
Not every seizure is epilepsy, and not every loss of consciousness is a seizure.
Seizure categories
| Type | Typical features | |
|---|---|---|
| Focal onset | Begins in one network or hemisphere | May have motor, sensory, autonomic, or psychic symptoms |
| Generalized onset | Bilateral network involvement at onset | Includes absence, tonic-clonic, myoclonic, and atonic seizures |
| Unknown onset | Insufficient information to classify initially | Requires further evaluation |
A focal seizure that begins in the right hand and then spreads up the arm is best described as:
It starts in one region and then spreads through adjacent motor cortex.
Correct answer: Focal onset with spread
What is the usual first test after a first-time unprovoked seizure?
Evaluation commonly includes EEG and neuroimaging to assess for structural or epileptiform causes.
Correct answer: brain imaging and EEG
Mechanisms of Epileptogenesis
Why seizures happen
Seizures can arise from altered excitation-inhibition balance, channel dysfunction, cortical injury, developmental lesions, infection, tumor, metabolic disturbance, or genetic predisposition.
Common seizure triggers or causes
Acute symptomatic
- Electrolyte disturbance
- Intoxication or withdrawal
- Acute stroke or infection
Structural epilepsy
- Cortical malformation
- Scar tissue
- Tumor or prior injury
Which factor commonly lowers seizure threshold?
Sleep deprivation is a classic seizure trigger.
Correct answer: Sleep deprivation
What is status epilepticus?
It is a neurologic emergency requiring rapid treatment.
Correct answer: a seizure that is prolonged or recurrent without recovery of consciousness
Treatment Principles
Clinical approach to a patient with seizures
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1
Step 1: Stabilize airway, breathing, circulation, and glucose.
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2
Step 2: Determine whether the event was epileptic, provoked, or non-epileptic.
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Step 3: Identify triggers, medication adherence, and structural causes.
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Step 4: Choose antiseizure therapy based on seizure type and patient context.
Which emergency medication class is commonly used first for active convulsive status epilepticus?
Benzodiazepines are first-line for aborting active convulsive seizures.
Correct answer: Benzodiazepines
Why is seizure classification important for treatment?
Some antiseizure medications are better for focal seizures, while others are preferred for generalized syndromes.
Correct answer: because drug choice depends on seizure type and syndrome