Seizures & Epilepsy: Focal vs Generalized (Medical Education Neuro)

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

That's it. Brief, stereotyped blank stares dozens of times daily in a school-age kid = classic absence seizure. The "picks up right where he left off" is the giveaway · no postictal confusion. EEG would show 3 Hz spike-and-wave. clinical medicine LOVE testing this against complex partial (focal with impaired awareness), which has a postictal period.

Good instinct · both can cause "staring." But complex partial seizures have a postictal period (confusion after), usually last 1-2 minutes, and happen a few times per week, not dozens per day. Absence = brief (seconds), no postictal, can happen 50-100 times daily.

Myoclonic seizures are sudden brief jerks · not blank stares. Think "morning coffee spill" not "zoning out in class."

Tempting · but "stereotyped" episodes (identical each time) happening dozens of times daily aren't daydreaming. You can snap someone out of a daydream. You can't snap someone out of an absence seizure. Also: the EEG during an episode would show 3 Hz spike-and-wave, not normal alpha rhythm.

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 clinical practice: 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. clinical medicine use both naming systems.

Generalized Seizure Types

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

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.

Focal vs Generalized · Side by Side

The single fork in the road. Get this wrong and every downstream decision is wrong.

Focal · formerly partial

Generalized

Onset

Single hemisphere. Starts in one spot, may stay there.

Both hemispheres from the very first second. No focal onset.

Awareness

Aware (formerly simple partial) OR impaired awareness (formerly complex partial). The aura is awareness retained.

Starts with loss of consciousness. No aura. No focal warning. The whole brain blinks at once.

Other

May progress to bilateral and to loss of consciousness (focal to bilateral tonic-clonic).

Status epilepticus > 5 min · neurons are dying; treat now.

Subtypes

Temporal lobe MCaura, staring + face / mouth automatism, unaware Frontal lobemotor symptoms, Todd paralysis, aware Parietal lobesensory symptoms, aware Occipitalvisual · super rare

Tonic-cloniccontractions: stiffening + jerking Myoclonicbilateral brief, sudden jerking Absencestaring < 20 s · 3 Hz spike & wave Atonicsudden loss of muscle tone · fall

Temporal lobe is the most common focal site, and the one clinical medicine love to disguise as something else. Staring + lip smacking + a feeling of déjà vu beforehand · that's not absence, that's temporal.

🔑Focal = Fraction of brain (one hemisphere). Generalized = Goodbye consciousness (both hemispheres, immediate).

EEG Patterns · See the Seizure

The Patterns That Show Up in clinical practice

You won't read raw EEGs on Step/clinical medicine, 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 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

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 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.

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 clinical medicine 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	,

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

Drug	Side Effect clinical medicine 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)

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.

Drug of Choice · Tap to Reveal

Tap each seizure type. Try to call the drug before you flip it. This is the highest-yield table on the page.

Focal

Temporal lobe seizures

Aura · staring · lip smacking

CarbamazepineSodium channel blocker. Watch for SIADH, agranulocytosis, SJS in HLA-B*1502.

Generalized

Generalized seizures

Both hemispheres, immediate LOC

Children: Phenobarbital
Adults: Phenytoin, Levetiracetam, Valproic AcidAvoid carbamazepine · it worsens generalized epilepsy.

Generalized

Absence seizures

5-15 s blank stare · 3 Hz spike & wave

EthosuximideT-type Ca²⁺ channel blocker in thalamus. Absence only. If absence + GTC, switch to valproate.

Generalized

Myoclonic seizures

Brief, sudden bilateral jerks

Valproic AcidBroadest-spectrum AED. Levetiracetam is the pregnancy-friendly alternative.

Emergency

Status epilepticus

> 5 min · neurons dying

Diazepam (lorazepam IV also first-line)Then phenytoin / fosphenytoin if recurrent. Benzos first. Always.

Peds

Febrile seizures

6 mo to 5 yrs · fever-triggered GTC

AcetaminophenTreat the fever, not the seizure. No chronic AED. Simple febrile = reassurance only.

Peds

Infantile spasms (West)

3-12 mo · hypsarrhythmia · regression

ACTH injectionsVigabatrin if tuberous sclerosis. Treat fast · delay worsens developmental outcome.

Withdrawal

Alcohol withdrawal seizure

CIWA rising · 6-48 hr after last drink

ChlordiazepoxideLong-acting benzo · smooths the withdrawal curve. Add thiamine before glucose.

If the seizure is generalized, your default reach is valproate (or levetiracetam in women of childbearing age). The exceptions are the two clinical medicine love to test: ethosuximide for pure absence, carbamazepine only for focal (it worsens generalized).

🔑Drug pairs: Temporal · Carba. Absence · Etho. Status · Diaz. West · ACTH. Febrile · Tylenol. Alcohol · Chlordiaz.

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." clinical medicine 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

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 clinical medicine 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)

Seizure Type Showdown

Tap each card to flip it and reveal the board-critical details. Know your enemy.

💭

Absence

Childhood epilepsy

Absence Seizure

Age 4-10 yrs, blank stare 5-15 sec
No postictal period (abrupt off)
Dozens per day, triggered by hyperventilation
EEG: 3 Hz spike-and-wave
Rx: Ethosuximide (pure) / Valproate (+GTC)
Avoid: Carbamazepine (worsens)

⚡

GTC

Generalized tonic-clonic

Generalized Tonic-Clonic

Stiffening (tonic) then rhythmic jerking (clonic)
Tongue biting (lateral!), incontinence
Postictal confusion, drowsiness
No aura = primary generalized
Rx: Valproate, Lamotrigine, Levetiracetam
Avoid: Carbamazepine (if primary generalized)

☕

JME

Juvenile myoclonic epilepsy

JME

Morning jerks, spills coffee/cereal
Consciousness preserved during jerks
Triggered by sleep deprivation + alcohol
EEG: 4-6 Hz poly-spike-and-wave
Rx: Valproate, Levetiracetam
Lifelong treatment (90% relapse off AEDs)

🧠

Focal

With / without awareness

Focal Seizure

One hemisphere onset, aura = retained awareness
Temporal: deja vu, epigastric rising, lip smacking
Postictal if impaired awareness
Todd's paralysis = post-seizure focal weakness
Rx: Carbamazepine, Lamotrigine, Levetiracetam
Workup: MRI brain for structural lesion

💥

Atonic

Drop attacks

Atonic Seizure

Sudden loss of ALL muscle tone
Face-first falls, needs a helmet
Associated with Lennox-Gastaut
Lennox-Gastaut EEG: slow spike-wave <2.5 Hz
Rx: Valproate, Lamotrigine, Rufinamide
Consider corpus callosotomy if refractory

⏱

Status EP

Neurological emergency

Status Epilepticus

Seizure >5 min OR 2+ without recovery
Step 1: Lorazepam IV (IM midazolam if no IV)
Step 2 (15-20 min): Fosphenytoin IV
Step 3 (30+ min): Intubate + propofol/midazolam drip
Goal: burst suppression on continuous EEG
Neurons die. Treat fast.