Seizures & Epilepsy

A 22-year-old is staring blankly, smacking her lips. Focal or generalized? Which drug? And when does "seizure" become "emergency"?

Quick — before you learn anything:
A 7-year-old boy is brought in by his teacher. She says he "zones out" in class for 10-15 seconds at a time, sometimes dozens of times a day. He doesn't fall. He doesn't shake. He just... goes blank. Afterward he picks up right where he left off like nothing happened.
Complex partial (focal) seizure
Absence seizure
Myoclonic seizure
Daydreaming / not a seizure
The Classification That Matters

Focal vs Generalized: The One Question

Every seizure classification starts with one question: does the abnormal electrical activity start in one spot, or everywhere at once?

  • Focal = starts in one hemisphere. Can spread (focal to bilateral tonic-clonic). The patient may have an aura — that's a focal seizure with awareness retained.
  • Generalized = both hemispheres from the start. No aura. No focal onset.

Why this matters for boards: the classification determines the drug. Get the classification wrong, you pick the wrong drug.

Focal seizures were formerly called "partial" seizures. Old terminology: simple partial (awareness retained) → focal aware. Complex partial (awareness impaired) → focal with impaired awareness. Boards use both naming systems.

Generalized Seizure Types

TypeWhat HappensKey FeatureAge
Tonic-Clonic Stiffening → rhythmic jerking → postictal Postictal confusion, tongue biting, incontinence Any age
Absence Brief blank stare (5-15 sec), abrupt onset/offset No postictal period. Dozens/day. 3 Hz spike-and-wave 4-10 years
Myoclonic Sudden, brief muscle jerks Morning jerks → spill coffee. Consciousness preserved Adolescence (JME)
Atonic Sudden loss of muscle tone "Drop attacks" — falls face-first. Needs a helmet. Childhood (Lennox-Gastaut)
Tonic Sustained stiffening only Arms extend, back arches. No clonic phase. Lennox-Gastaut
Clonic Rhythmic jerking only No tonic phase. Rare in isolation. Neonates
Board Trap: "Absence vs focal with impaired awareness" — both cause staring. Absence = brief (seconds), no postictal, dozens/day, childhood, triggered by hyperventilation. Focal impaired awareness = longer (1-2 min), postictal confusion, automatisms (lip smacking, fumbling), adults, often temporal lobe origin.
🔑Absence = Abrupt on, Abrupt off, Absolutely no postictal. If there's confusion after, it's focal.
EEG Patterns — See the Seizure

The Patterns That Show Up on Boards

You won't read raw EEGs on Step/COMLEX, but you need to match the pattern to the seizure type.

Interactive EEG Viewer

Normal alpha rhythm (8-13 Hz). Symmetric, organized. This is what you want to see.
EEG PatternSeizure TypeBoard Buzzword
3 Hz spike-and-waveAbsence"Generalized 3 Hz spike-and-wave"
4-6 Hz poly-spike-and-waveJME (Myoclonic)"Poly-spike" = myoclonic
Slow spike-and-wave (<2.5 Hz)Lennox-GastautMultiple seizure types + cognitive decline
HypsarrhythmiaInfantile spasms (West)Chaotic, disorganized. Treat with ACTH or vigabatrin
Temporal spikesFocal (temporal lobe)Most common focal epilepsy in adults
3 Hz spike-and-wave = absence seizure. This is one of the most tested associations. If a board question says "generalized 3 Hz spike-and-wave," the answer is absence seizure, and the drug is ethosuximide (if pure absence) or valproate (if also has GTC).
Focal Seizures — The Aura Is Your Friend

Aura = Focal Seizure with Retained Awareness

An aura isn't a warning before a seizure — it IS the seizure. It's a focal seizure confined to one area, and the patient stays aware during it.

The aura localizes the focus:

Aura TypeLobeWhat They Report
Déjà vu, fear, epigastric risingTemporal"I got this weird feeling in my stomach rising up" + "I've been here before"
Flashing lights, visual distortionsOccipital"I saw zigzag lines" (also consider migraine)
Tingling, numbness in a limbParietal"My hand went numb and it spread up my arm"
Involuntary movement, twitchingFrontalBrief, nocturnal, bizarre posturing. Often misdiagnosed.

Focal to Bilateral Tonic-Clonic

Formerly called "secondarily generalized." A focal seizure that spreads to involve both hemispheres. Board clue: any GTC preceded by an aura or focal symptoms = focal to bilateral, NOT primary generalized.

  • Jacksonian march = motor seizure that "marches" along the homunculusThe motor and sensory cortex are organized in a map of the body (homunculus). Adjacent body parts are represented by adjacent cortex. A seizure spreading through motor cortex will move systematically: thumb → hand → arm → face. — starts in one area, spreads to adjacent body parts. Classic board scenario.
Board Trap: Todd's paralysis — focal weakness AFTER a seizure, lasting minutes to hours. Looks like a stroke. But it resolves completely. If a board question gives you a patient with sudden weakness after a witnessed seizure, Todd's is the answer. Don't order tPA.
🔑Todd was todally wiped out after his seizure (temporary paralysis, full recovery)
Diagnosis Detective — Name That Seizure

Case 1: One Clue at a Time

Clues appear one at a time. Can you figure it out before all clues are revealed?

1. 16-year-old boy, brought in after a "seizure" at breakfast.
2. He was eating cereal and suddenly his arms jerked — spoon flew across the table.
3. He was fully conscious the entire time. Lasted about 1 second.
4. His mom says this happens "every morning." Sleep deprivation makes it worse.
5. He also had one episode of GTC seizure last month while staying up gaming all night.
Tonic-Clonic
Absence
JME (Myoclonic)
Focal
Need more clues?

Case 2: One Clue at a Time

Same deal. Guess as soon as you're confident.

1. 32-year-old woman found on the ground, confused and drowsy.
2. Coworkers say she suddenly stiffened and fell out of her chair.
3. Then her whole body started shaking rhythmically for about 2 minutes.
4. She bit the side of her tongue. She was incontinent of urine.
5. Now 15 minutes later she's still confused and sleepy. No preceding aura reported.
GTC
Absence
Focal → Bilateral
Status Epilepticus
Need more clues?
AED Selection — The Drug That Matches the Seizure

First-Line AEDs by Seizure Type

This is the part boards test most directly. Match the seizure → pick the drug.

Seizure TypeFirst LineAlternativesAvoid
Focal (any) Carbamazepine, Lamotrigine, Levetiracetam Oxcarbazepine, Phenytoin
GTC (primary generalized) Valproate, Lamotrigine, Levetiracetam Topiramate Carbamazepine (can worsen)
Absence (only) Ethosuximide Valproate Carbamazepine, Phenytoin
Absence + GTC Valproate Lamotrigine Carbamazepine
JME (Myoclonic) Valproate, Levetiracetam Lamotrigine (careful — can worsen myoclonus) Carbamazepine, Phenytoin
Infantile Spasms ACTH, Vigabatrin Valproate
Lennox-Gastaut Valproate, Lamotrigine Rufinamide, Clobazam
Board Trap: Carbamazepine worsens generalized seizures. If someone with absence or JME gets started on carbamazepine, their seizures will get worse. This is a CLASSIC board question. "Patient with absence seizures was started on a new medication, now having more seizures" → they gave carbamazepine.
Ethosuximide = absence only. It works by blocking T-type calcium channelsT-type (transient) calcium channels in thalamic neurons are responsible for the rhythmic thalamocortical oscillations that produce the 3 Hz spike-and-wave pattern. Blocking them stops the oscillation = stops absence seizures. Ethosuximide only blocks T-type channels, which is why it only works for absence — other seizure types use different mechanisms. in the thalamus. It does NOTHING for GTC. So if a kid has absence AND GTC, you pick valproate instead.
🔑Etho-SUCKS-imide — it SUCKS at everything except absence. One seizure type, one drug, one mechanism (T-type Ca²⁺).

High-Yield Side Effects

DrugSide Effect Boards Love
PhenytoinGingival hyperplasiaPhenytoin stimulates fibroblast proliferation in the gums → overgrown gum tissue. Also causes hirsutism and coarsened facial features (fetal hydantoin syndrome in pregnancy). Zero-order kinetics = small dose changes → big level changes → toxicity (nystagmus, ataxia, diplopia)., hirsutism, zero-order kinetics (toxicity risk), teratogenic (fetal hydantoin syndrome), SJS in HLA-B*1502
ValproateTeratogenic (#1 — neural tube defects), hepatotoxic, pancreatitis, weight gain, tremor, thrombocytopenia. Avoid in women of childbearing age if alternatives exist.
CarbamazepineSIADHCarbamazepine stimulates ADH release → water retention → dilutional hyponatremia. Clinically significant in ~5% of patients. Check sodium levels, especially in elderly patients on carbamazepine. (hyponatremia), agranulocytosis, SJS (HLA-B*1502), induces CYP450 (drug interactions)
LamotrigineSJS/TEN (especially if titrated too fast), relatively safe in pregnancy
LevetiracetamBehavioral changes (irritability, "Keppra rage"), but few drug interactions. Safest in pregnancy after lamotrigine.
TopiramateKidney stones, weight loss, cognitive slowing ("Dopamax"), teratogenic (cleft lip/palate)
Board Trap: Pregnant woman with epilepsy — valproate is the WORST choice (highest teratogenicity, neural tube defects). Lamotrigine and levetiracetam are preferred in pregnancy. But don't stop AEDs — uncontrolled seizures are also dangerous to the fetus.
Status Epilepticus — The Emergency

Definition

Status epilepticus = seizure lasting >5 minutes, or 2+ seizures without returning to baseline between them. This is a neurological emergency — neurons are dying.

Old definition was 30 minutes, but you treat at 5 because brain damage starts before 30.

Treatment Timeline

0-5 minutes — ABCs + Stabilize
Airway, breathing, circulation. Check glucose. Thiamine if malnourished/alcoholic. IV access. Place on side (recovery position).
5 minutes — First-Line: BENZODIAZEPINES
IV lorazepam (preferred) or IV diazepam. If no IV access: IM midazolam or rectal diazepam. Benzos work fast but wear off — you NEED a second agent.
15-20 minutes — Second-Line: FOSPHENYTOIN
If benzos failed. IV fosphenytoin (preferred over phenytoin — less tissue necrosis). Alternatives: valproate IV, levetiracetam IV.
30+ minutes — Refractory Status: INTUBATION + DRIPS
RSI + continuous infusion: midazolam drip, propofol drip, or pentobarbital drip. ICU level care. Continuous EEG monitoring. Burst suppression is the goal.
Benzos first. Always. Lorazepam IV is the preferred benzo for status epilepticus (longer duration of action in the brain than diazepam despite shorter half-life). If no IV, IM midazolam works faster than rectal diazepam.
🔑Status protocol: Benzos → Fosphenytoin → Barbiturates/drips. BFB = Big F***ing emergency Before brain damage.
PNES — The Seizure That Isn't

Psychogenic Non-Epileptic Spells (PNES)

Formerly "pseudoseizures." Boards test this diagnosis and the clues that distinguish it from real seizures.

FeatureReal Seizure (Epileptic)PNES
Eyes during eventOpen (usually)Closed (forced eye closure)
DurationUsually <2 min (GTC)Often prolonged (>5 min)
MovementsRhythmic, synchronousAsynchronous, waxing/waning, pelvic thrusting
Tongue bitingLateral tongueTip of tongue (if at all)
PostictalYes — confusion, drowsinessOften rapid return to baseline
ProlactinElevated (within 20 min)Normal
EEG during eventEpileptiform activityNormal EEG
Gold standard DxVideo EEG monitoring — captures event with normal EEG = PNES
Board Trap: Eyes closed during seizure = think PNES. Real GTC seizures almost always have eyes open. Forced eye closure is one of the strongest predictors of psychogenic etiology. But remember: 10-40% of PNES patients ALSO have real epilepsy. They're not mutually exclusive.
PNES is NOT "faking it." It's a real condition — the brain is producing real symptoms, just not through epileptic mechanisms. Treatment is psychotherapy, not AEDs. Putting a PNES patient on AEDs exposes them to side effects with zero benefit.
Board-Favorite Epilepsy Syndromes

JME (Juvenile Myoclonic Epilepsy)

The adolescent epilepsy syndrome boards love. Triad: myoclonic jerks (morning), GTC seizures, sometimes absence. Triggered by sleep deprivation and alcohol. EEG: 4-6 Hz poly-spike-and-wave. First-line: valproate (or levetiracetam in women). Lifelong treatment — almost always relapses if AEDs stopped.

Infantile Spasms (West Syndrome)

The triad: infantile spasms (sudden flexion/extension, often in clusters), hypsarrhythmia on EEG, developmental regression. Age 3-12 months. Emergency — treat immediately with ACTH or vigabatrin (especially if tuberous sclerosis). Delay = worse developmental outcome.

Lennox-Gastaut Syndrome

Age 2-6 years. Multiple seizure types (tonic, atonic, absence, GTC). Slow spike-and-wave (<2.5 Hz) on EEG. Cognitive impairment. Refractory to treatment. Atonic "drop attacks" are the dangerous ones — kids need helmets.

Febrile Seizures

Simple febrile: GTC, <15 min, once in 24 hours, age 6 months to 5 years, no focal features. No workup needed. No treatment. No increased epilepsy risk.

Complex febrile: Focal, >15 min, recurs within 24 hours, or age <6 months. Workup needed (LP if <12 months). Slightly increased epilepsy risk.

Board Trap: Simple febrile seizure = reassurance only. Don't order EEG, don't order MRI, don't start AEDs. Parents are terrified — you educate them. The only management for a simple febrile seizure is treating the underlying illness (antipyretics for comfort, not seizure prevention). Complex febrile → that's when you investigate.
Elimination Challenge — Clinical Vignettes

5 patients with seizures. Clues eliminate one at a time.

GTC
Absence
JME
Atonic
Focal
Clue 1: The patient has no postictal confusion after any episode.
This eliminates one type — which one always has a postictal period?
Clue 2: Episodes happen dozens of times a day, each lasting only 5-15 seconds.
Too brief and too frequent for one of these — which one?
Clue 3: There are no motor symptoms — no jerks, no drops, no stiffening.
This rules out two more motor seizure types.
Clue 4: Patient is 8 years old. EEG shows 3 Hz spike-and-wave. Provoked by hyperventilation.
One card left. What is it?
Clinical Decision Tree
A patient has a seizure. First question: does the seizure have focal features or is it generalized from onset?
Focal features (aura, one-sided onset, automatisms)
Generalized from onset (no focal features)
Quiz — 4 Patients Walk In
4 patients with seizure-related complaints just walked into your clinic. At least try not to make things worse.