Seizures and Epilepsy (All Seizure Types): Classification, Diagnosis, and Emergency Management Guide

1. What Is a Seizure?

A seizure is a transient, uncontrolled electrical discharge of neurons in the brain, causing altered behavior, sensation, movement, or consciousness.

• Epilepsy = ≥2 unprovoked seizures >24h apart

• Seizures are a symptom, not a diagnosis—always search for the cause
  

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2. ⚡ Classification of Seizures (According to ILAE 2017)

Seizures are first classified by onset (where they start), then by level of awareness and symptoms.

🔸 A. Focal Seizures (Partial)

Start in one hemisphere of the brain. Often linked to underlying structural lesions.

2.1 Focal Aware Seizure (Simple Partial)

• Awareness preserved

• Motor: jerking of one limb (Jacksonian march)

• Sensory: tingling, flashing lights

• Autonomic: flushing, GI upset, palpitations

• Psychic: déjà vu, fear

🧠 Localization:

• Motor cortex (precentral gyrus): clonic limb movement

• Occipital lobe: visual aura

• Insular cortex: visceral aura (epigastric rising)

🔎 Associated Conditions:

• Focal cortical dysplasia

• CNS tumors

• Post-stroke seizures

• Mesial temporal sclerosis

• Neurocysticercosis in endemic areas

2.2 Focal Impaired Awareness Seizure (Complex Partial)

• Altered consciousness

• Often begins with aura → motor automatisms (lip-smacking, chewing)

• Postictal confusion is common

🧠 Localization: Temporal lobe most common🔎 Diseases:

• Mesial temporal lobe epilepsy (MTLE)

• Hippocampal sclerosis

• Post-traumatic epilepsy

• Low-grade gliomas

2.3 Focal to Bilateral Tonic-Clonic

• Begins as focal (aura/motor) → spreads to involve both hemispheres

• Features like tonic-clonic seizure but often starts with warning

🧠 Important clue: Always investigate for structural lesions!🔎 Diseases:

• Post-stroke epilepsy

• CNS tumor

• AVM

• Remote symptomatic seizure
  

🔹 B. Generalized Seizures

Begin simultaneously in both hemispheres. No aura. Awareness is usually lost.

2.4 Absence Seizures (Petit Mal)

• Sudden behavioral arrest ("staring into space")

• Lasts <10 seconds

• No postictal confusion

• 3 Hz spike-and-wave pattern on EEG

🧠 Typical in childhood🔎 Diseases:

• Childhood Absence Epilepsy (CAE): onset 4–10 yrs

• Juvenile Absence Epilepsy (JAE)

• Often have family history (idiopathic generalized epilepsy)

2.5 Generalized Tonic-Clonic Seizures (GTCS)

• Tonic phase: stiffening (10–20 sec) + cry, fall, cyanosis

• Clonic phase: rhythmic jerking (30–90 sec)

• Postictal phase: confusion, sleep, headache

🧠 Most common generalized seizure🔎 Diseases:

• Juvenile Myoclonic Epilepsy (JME)

• Idiopathic Generalized Epilepsy

• Genetic epilepsy syndromes

• Metabolic disturbances (hypoglycemia, hyponatremia)

• Eclampsia (GTCS + pregnancy)

2.6 Myoclonic Seizures

• Sudden, brief muscle jerks (often arms)

• Preserved awareness

• Typically in the morning

🧠 Localization: Subcortical motor structures🔎 Diseases:

• Juvenile Myoclonic Epilepsy (JME) – hallmark

• Lafora disease, Unverricht-Lundborg

• Post-hypoxic myoclonus

• Metabolic causes: uremia, hepatic encephalopathy

2.7 Atonic Seizures ("Drop attacks")

• Sudden loss of muscle tone → collapse

• High risk of trauma

• No warning; no postictal confusion

🔎 Diseases:

• Lennox-Gastaut Syndrome (LGS)

• Dravet syndrome

• Structural brain lesions in children

2.8 Tonic or Clonic Alone

• Rare

• Usually seen in infants or LGS
  

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3. 🧪 Diagnostic Evaluation

Modality	Purpose
EEG	Localize focus, classify seizure
MRI Brain	Rule out lesion: stroke, tumor, dysplasia
CT Head	Rapid rule-out (bleed, trauma)
Blood tests	Glucose, Na+, Ca2+, Mg2+, LFT, BUN/Cr, CBC
LP	If infection (meningitis, encephalitis) suspected
Toxicology screen	Suspected ingestion (alcohol, drugs)

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4. 🆘 Status Epilepticus (SE)

Definition: Seizure >5 min OR ≥2 seizures without full recovery

Types:

• Convulsive SE: GTCS without recovery

• Non-convulsive SE: prolonged altered mental status + EEG confirmation

Stepwise Management:

1. 0–5 min: ABCs, IV access, glucose

2. 5–20 min: Lorazepam 0.1 mg/kg IV

3. 20–40 min: Fosphenytoin 20 mg PE/kg IV, Valproate, Levetiracetam

4. >40 min (Refractory): Intubate, sedate (Midazolam, Propofol)

🔎 Common Causes:

• AED withdrawal/noncompliance

• Hypoglycemia, hyponatremia

• Alcohol withdrawal

• Encephalitis

• Stroke

• Intracerebral hemorrhage
  

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5. 👶 Pediatric Focus: Febrile Seizures

Feature	Simple	Complex
Duration	<15 min	>15 min
Focal?	No	Yes
Recurrent in 24h	No	Yes
Postictal deficit	No	Yes
Age	6mo–5y	Any
Risk of epilepsy	Slight ↑	Higher ↑↑

Initial Workup (Complex only):

• LP (if signs of meningitis)

• Electrolytes

• EEG and MRI if recurrent or focal signs
  

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6. 🧾 OSCE Checklist Summary: “Is This a Real Seizure?”

🔸 Pre-Ictal:

• Aura?

• Triggers (light, alcohol, sleep loss)?

• Position (standing → syncope?)

🔸 Ictal:

Sign	Real Seizure	PNES
Duration	<2 min	>5 min
Movements	Rhythmic, stereotyped	Flailing, irregular
Tongue biting	Lateral	Absent or tip
Incontinence	Common	Rare
Eyes	Open	Tightly shut
Awareness	Lost	Often preserved
Postictal Confusion	Yes	No

🔸 Post-Ictal:

• Drowsiness?

• Headache?

• Weakness (Todd’s paralysis)?

• Slow recovery → more likely epileptic
  

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7. 💊 Treatment by Seizure Type

Type	First-line AEDs
Focal	Carbamazepine, Lamotrigine, Levetiracetam
Absence	Ethosuximide, Valproate
Myoclonic	Valproate, Levetiracetam
GTCS	Valproate, Levetiracetam
Atonic/LGS	Valproate, Rufinamide, Clobazam

🔹 Adjust AED based on:

• Age

• Pregnancy (Avoid Valproate if possible)

• Liver/renal function

• Side effect profile
  

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8. 📘 Diseases Associated with Seizure Types

Seizure Type	Diseases
Focal Aware/Impaired	Stroke, MTLE, Tumor, Trauma, Infection
GTCS	Genetic epilepsy, Metabolic encephalopathy, Eclampsia
Absence	CAE, JAE
Myoclonic	JME, Mitochondrial disorders, Post-anoxic
Atonic	LGS, Congenital brain malformations
Febrile	Viral illness + fever in children
Status Epilepticus	AED noncompliance, Alcohol withdrawal, CNS infection

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🎯 High-Yield Mnemonics

JME Triad:

• Myoclonic jerks

• Generalized tonic-clonic seizures

• Absence seizures

Causes of Seizure (VITAMINS):

• Vascular (stroke, bleed)

• Infection (meningitis, encephalitis)

• Trauma (TBI)

• Autoimmune (SLE, MS)

• Metabolic (hypoNa+, hypoCa2+, hypoGly)

• Idiopathic

• Neoplasm

• Substance (alcohol withdrawal, drugs)

  
  

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✅ Summary

Understanding seizure semiology helps:

• Localize brain dysfunction

• Select a proper AED

• Recognize dangerous situations (e.g., SE, focal with structural cause)

Use a structured diagnostic strategy:

• History (including witness)

• Physical + neuro exam

• EEG + Imaging

• Metabolic and toxic screening