Seizures and Epilepsy (All Seizure Types): Classification, Diagnosis, and Emergency Management Guide
- Mayta
- May 26
- 4 min read
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
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
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) |
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:
0–5 min: ABCs, IV access, glucose
5–20 min: Lorazepam 0.1 mg/kg IV
20–40 min: Fosphenytoin 20 mg PE/kg IV, Valproate, Levetiracetam
>40 min (Refractory): Intubate, sedate (Midazolam, Propofol)
🔎 Common Causes:
AED withdrawal/noncompliance
Hypoglycemia, hyponatremia
Alcohol withdrawal
Encephalitis
Stroke
Intracerebral hemorrhage
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
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
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
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 |
🎯 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)
✅ 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
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