A 22-year-old is staring blankly, smacking her lips. Focal or generalized? Which drug? And when does "seizure" become "emergency"?
Every seizure classification starts with one question: does the abnormal electrical activity start in one spot, or everywhere at once?
Why this matters for boards: the classification determines the drug. Get the classification wrong, you pick the wrong drug.
| Type | What Happens | Key Feature | Age |
|---|---|---|---|
| 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 |
You won't read raw EEGs on Step/COMLEX, but you need to match the pattern to the seizure type.
| EEG Pattern | Seizure Type | Board Buzzword |
|---|---|---|
| 3 Hz spike-and-wave | Absence | "Generalized 3 Hz spike-and-wave" |
| 4-6 Hz poly-spike-and-wave | JME (Myoclonic) | "Poly-spike" = myoclonic |
| Slow spike-and-wave (<2.5 Hz) | Lennox-Gastaut | Multiple seizure types + cognitive decline |
| Hypsarrhythmia | Infantile spasms (West) | Chaotic, disorganized. Treat with ACTH or vigabatrin |
| Temporal spikes | Focal (temporal lobe) | Most common focal epilepsy in adults |
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 Type | Lobe | What They Report |
|---|---|---|
| Déjà vu, fear, epigastric rising | Temporal | "I got this weird feeling in my stomach rising up" + "I've been here before" |
| Flashing lights, visual distortions | Occipital | "I saw zigzag lines" (also consider migraine) |
| Tingling, numbness in a limb | Parietal | "My hand went numb and it spread up my arm" |
| Involuntary movement, twitching | Frontal | Brief, nocturnal, bizarre posturing. Often misdiagnosed. |
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.
Clues appear one at a time. Can you figure it out before all clues are revealed?
Same deal. Guess as soon as you're confident.
This is the part boards test most directly. Match the seizure → pick the drug.
| Seizure Type | First Line | Alternatives | Avoid |
|---|---|---|---|
| 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 | — |
| Drug | Side Effect Boards Love |
|---|---|
| Phenytoin | Gingival 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 |
| Valproate | Teratogenic (#1 — neural tube defects), hepatotoxic, pancreatitis, weight gain, tremor, thrombocytopenia. Avoid in women of childbearing age if alternatives exist. |
| Carbamazepine | SIADHCarbamazepine 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) |
| Lamotrigine | SJS/TEN (especially if titrated too fast), relatively safe in pregnancy |
| Levetiracetam | Behavioral changes (irritability, "Keppra rage"), but few drug interactions. Safest in pregnancy after lamotrigine. |
| Topiramate | Kidney stones, weight loss, cognitive slowing ("Dopamax"), teratogenic (cleft lip/palate) |
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.
Formerly "pseudoseizures." Boards test this diagnosis and the clues that distinguish it from real seizures.
| Feature | Real Seizure (Epileptic) | PNES |
|---|---|---|
| Eyes during event | Open (usually) | Closed (forced eye closure) |
| Duration | Usually <2 min (GTC) | Often prolonged (>5 min) |
| Movements | Rhythmic, synchronous | Asynchronous, waxing/waning, pelvic thrusting |
| Tongue biting | Lateral tongue | Tip of tongue (if at all) |
| Postictal | Yes — confusion, drowsiness | Often rapid return to baseline |
| Prolactin | Elevated (within 20 min) | Normal |
| EEG during event | Epileptiform activity | Normal EEG |
| Gold standard Dx | Video EEG monitoring — captures event with normal EEG = PNES | |
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.
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.
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.
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.