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

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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

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:

🔸 Post-Ictal:

• Drowsiness?
• Headache?
• Weakness (Todd’s paralysis)?
• Slow recovery → more likely epileptic

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7. 💊 Treatment by Seizure Type

🔹 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

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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