372.1 🎓 醫孞生版

372.1.0.1 📌 䞀頁重點

372.1.0.1.1 Definitions

372.1.1 Seizure

  • Transient signs/symptoms
  • Abnormal excessive/synchronous neuronal activity

372.1.2 Epilepsy

  • ≥ 2 unprovoked seizures, OR
  • 1 unprovoked + high recurrence risk, OR
  • Epilepsy syndrome

372.1.3 Provoked Seizure

  • Acute symptomatic
  • NOT epilepsy
  • Examples: hypoglycemia, hyponatremia, alcohol withdrawal, drug toxicity, fever, stroke, head injury
372.1.3.0.1 ILAE 2017 Classification

372.1.4 Step 1: Onset

  • Focal (one hemisphere)
  • Generalized (both hemispheres)
  • Unknown

372.1.5 Step 2: Awareness

  • Focal aware (formerly “simple partial”)
  • Focal impaired awareness (formerly “complex partial”)
  • Awareness not used for generalized

372.1.6 Step 3: Motor vs Non-Motor Features

Focal: - Motor: clonic, tonic, atonic, myoclonic, automatisms, hyperkinetic, epileptic spasms - Non-motor: sensory, emotional/cognitive, autonomic, behavior arrest

Generalized: - Motor: tonic-clonic, myoclonic, atonic, tonic, clonic, epileptic spasms - Non-motor (absence): typical, atypical, myoclonic, eyelid myoclonia

372.1.6.0.1 Common Seizure Types

372.1.7 Generalized Tonic-Clonic (GTC, Grand Mal)

  • LOC + body stiffens (tonic 10-30 sec) → rhythmic jerks (clonic 30-90 sec) → post-ictal confusion
  • Lateral tongue bite (specific!)
  • Incontinence (less specific)
  • Cyanosis, frothing
  • Lasts 1-3 min usually

372.1.8 Focal Aware (Simple Partial)

  • Awareness preserved
  • Sensory, motor, autonomic symptoms
  • Aura = focal aware seizure

372.1.9 Focal Impaired Awareness (Complex Partial)

  • Impaired awareness
  • Automatisms (lip smacking, picking)
  • 30 sec - 2 min
  • Post-ictal confusion
  • Temporal or frontal lobe

372.1.10 Absence (Petit Mal)

  • Childhood
  • Brief (5-10 sec)
  • Staring, no response
  • No post-ictal
  • May have eyelid blinking
  • EEG: 3 Hz spike-wave
  • Treatment: ethosuximide, valproate

372.1.11 Myoclonic

  • Brief shock-like jerks
  • JME (juvenile myoclonic epilepsy) — adolescents, morning

372.1.12 Atonic (Drop Attacks)

  • Sudden loss of tone
  • Falls
  • Lennox-Gastaut

372.1.13 Tonic

  • Sudden stiffening
  • May fall
372.1.13.0.1 Etiology by Age

372.1.14 Children

  • Idiopathic/genetic
  • Birth injury, anoxia
  • Congenital malformation
  • Febrile seizure
  • Infection
  • Trauma

372.1.15 Adults (Young)

  • Idiopathic/genetic (continued from childhood)
  • Trauma
  • Drug/alcohol withdrawal
  • Tumor
  • Infection
  • AVM

372.1.16 Adults (Older)

  • Stroke (most common cause new-onset > 60)
  • Tumor
  • Trauma
  • Dementia
  • Metabolic
  • Drug toxicity
372.1.16.0.1 Provoked vs Unprovoked

372.1.17 Provoked (Acute Symptomatic)

  • Within 7 days of acute insult
  • Examples:
    • Hypoglycemia, hyperglycemia (HHS)
    • Hyponatremia
    • Hypocalcemia
    • Alcohol withdrawal
    • Drug toxicity (cocaine, amphetamines)
    • Drug withdrawal (BZD)
    • Fever (children)
    • Stroke, head injury, brain surgery
    • CNS infection
  • Treat underlying; not epilepsy

372.1.18 Unprovoked

  • No acute trigger
  • Risk of recurrence after first: ~ 35-40%
  • After 2nd: > 70% (epilepsy)
  • Risk factors for recurrence: abnormal EEG, MRI, exam, family history
372.1.18.0.1 Workup

372.1.19 History

  • Witnessed account critical
  • Aura, ictal events, post-ictal state
  • Triggers
  • Family history
  • Medications, substances
  • Birth/development
  • Prior seizures

372.1.20 Examination

  • General + focused neuro
  • Skin (neurocutaneous — TS, NF, Sturge-Weber)

372.1.21 Investigations

  • Glucose, electrolytes (Na, Ca, Mg)
  • Toxicology
  • Pregnancy test (women)
  • CBC, LFTs, renal
  • CK (if prolonged)
  • ECG (rule out cardiogenic — long QT, etc.)
  • EEG (within 24 hr if possible)
    • Sleep + sleep-deprived increases yield
    • Ambulatory or video-EEG if uncertain
  • MRI brain (preferred over CT)
  • LP if meningitis suspected
  • Genetic testing in some cases

372.1.22 Distinguish from Mimics

  • Syncope (with brief myoclonic — “convulsive syncope”)
  • Psychogenic non-epileptic seizures (PNES) — gold standard video-EEG
  • TIA, migraine, complex sleep behavior
  • Movement disorders
372.1.22.0.1 Antiseizure Medications (ASMs)

372.1.23 Choice by Seizure Type

Focal-onset (all options effective): - Levetiracetam (Keppra) — first-line; minimal interactions - Lamotrigine — slow titration (SJS risk) - Lacosamide — IV available; PR interval caution - Brivaracetam — newer LEV analog, fewer behavioral SEs - Cenobamate — newer (2019), highly effective for refractory; DRESS risk - Older: carbamazepine, oxcarbazepine, phenytoin, valproate - Perampanel, eslicarbazepine, clobazam

Generalized: - Valproate (most effective; teratogenic — avoid in pregnancy) - Lamotrigine (good but worse for myoclonic in JME) - Levetiracetam - Topiramate - Zonisamide

Absence: - Ethosuximide (first-line) - Valproate - Lamotrigine

Myoclonic (JME): - Valproate (most effective) - Levetiracetam - Topiramate - Avoid: carbamazepine, oxcarbazepine, phenytoin, gabapentin (worsen myoclonic)

372.1.24 Adverse Effects to Know

Lamotrigine: SJS/TEN (slow titration!) Carbamazepine: SJS (HLA-B*1502 screening Asians), SIADH, AV block Valproate: hepatotoxic, pancreatitis, thrombocytopenia, teratogenic (NTD) Phenytoin: gum hyperplasia, hirsutism, ataxia, SJS, megaloblastic Topiramate: kidney stones, glaucoma, oligohidrosis, cognitive Zonisamide: similar to topiramate + rash Levetiracetam: behavioral (irritability, depression) Lacosamide: PR prolongation Vigabatrin: visual field constriction Perampanel: psychiatric BBW Cenobamate: DRESS (slow titration)

372.1.25 Pregnancy

  • Lamotrigine + levetiracetam safest
  • Avoid valproate (10% major malformations + cognitive)
  • Avoid topiramate (orofacial clefts, low birth weight)
  • Folate 0.4-5 mg/d
  • Continue ASMs (untreated seizures dangerous)
  • Multidisciplinary care

372.1.26 Withdrawal of ASMs

  • Consider after 2-5 years seizure-free
  • Slow taper
  • Risk factors for recurrence: abnormal EEG, MRI lesion, multiple ASMs needed
  • Driving implications
372.1.26.0.1 Refractory Epilepsy
  • 30% of epilepsy patients
  • Failure of 2 appropriate ASMs at adequate doses
  • Options:
    • Combination ASMs
    • Epilepsy surgery (resective for focal)
    • Vagus nerve stimulator (VNS)
    • RNS (Responsive Neurostimulation) — closed-loop
    • DBS (anterior thalamic nucleus)
    • Ketogenic diet (children mostly)
    • Cannabidiol (Epidiolex) — Dravet, LGS, TSC
    • Cenobamate
372.1.26.0.2 Status Epilepticus

See Ch372

372.1.26.0.3 SUDEP
  • Sudden Unexplained Death in Epilepsy
  • ~ 1.2/1000 patient-years overall
  • Refractory: 10x higher
  • Risk factors: GTC seizures, refractory, nocturnal, prone position
  • Mechanism likely cardio-respiratory
  • Counsel patients about risk
  • Seizure freedom is protective

372.1.26.1 🩺 床邊速查

  • Seizure types: focal (aware vs impaired) vs generalized (GTC, absence, myoclonic, atonic, tonic, clonic)
  • Provoked vs unprovoked — provoked NOT epilepsy
  • Workup: glucose + electrolytes + EEG + MRI brain (preferred)
  • ASM by type:
    • Focal: levetiracetam, lamotrigine, lacosamide, cenobamate
    • Generalized: valproate (most), lamotrigine, levetiracetam, topiramate
    • Absence: ethosuximide
    • Myoclonic: valproate, levetiracetam (avoid CBZ/OXC/PHT/GBP)
  • Pregnancy: lamotrigine + levetiracetam safest; avoid valproate
  • Refractory: surgery, VNS, RNS, DBS, ketogenic diet, cannabidiol
  • SUDEP: counsel patients