Neurology · PANCE / PANRE

Seizures and Epilepsy

Paroxysmal neurologic events from abnormal hypersynchronous cortical discharge.

Also known as: seizure, epilepsy, focal seizure, generalized seizure, tonic-clonic, grand mal, absence

Overview

A seizure is a transient occurrence of signs and/or symptoms due to abnormal, excessive, or synchronous neuronal activity in the brain. Epilepsy is a disease characterized by an enduring predisposition to seizures, defined by ILAE 2014 as: (1) ≥2 unprovoked seizures >24 h apart, OR (2) one unprovoked seizure plus ≥60% recurrence risk over next 10 years, OR (3) diagnosis of an epilepsy syndrome.

Epidemiology

Lifetime risk of a seizure ~10%; epilepsy prevalence ~1%. Bimodal age distribution — peaks in childhood and after age 65.

🔒 Free preview limit reached

Keep reading — start your free trial

You've read your 2 free diagnosis previews. Create your free account to unlock the full Seizures and Epilepsy outline — plus all 514 diagnoses, 3,500+ board-style questions, flashcards, and an AI tutor. Your 7-day free trial includes everything, and there's no credit card required.

Start your 7-day free trial → Sign in

Free to start · No credit card · Cancel anytime

Risk factors

Provoked (acute symptomatic) seizures: hypoglycemia, hyponatremia, hypocalcemia, alcohol/benzodiazepine withdrawal, fever (children), drugs (cocaine, tramadol, bupropion), eclampsia, acute stroke, head trauma, CNS infection, hypoxia
Unprovoked (epilepsy): prior stroke, traumatic brain injury, CNS infection, brain tumor, neurodegenerative disease, cortical malformations, genetic epilepsy syndromes, perinatal injury
Family history of epilepsy
Sleep deprivation, photic stimulation (triggers in susceptible patients)

Pathophysiology

Excessive excitation (glutamate-driven) and/or insufficient inhibition (GABA-driven) at the cortical level produces hypersynchronous neuronal firing. Focal seizures begin in a discrete area and may remain focal or evolve to bilateral involvement. Generalized seizures involve both hemispheres from the outset, often via thalamocortical circuits.

Clinical presentation

Symptoms

Focal (formerly partial) — aware: motor (clonic jerking), sensory (paresthesia), autonomic, psychic (déjà vu, fear)
Focal — impaired awareness: behavioral arrest, automatisms (lip smacking, picking), postictal confusion
Focal to bilateral tonic-clonic (formerly secondary generalization)
Generalized tonic-clonic: sudden LOC, tonic stiffening 10-20 s, clonic jerking 1-2 min, postictal confusion, tongue bite (lateral), urinary incontinence
Absence (typical childhood): brief staring spells with 3 Hz spike-wave on EEG, no postictal state
Myoclonic: brief shock-like jerks (juvenile myoclonic epilepsy classically morning jerks)
Atonic ('drop attacks'): sudden loss of tone, falls

Signs / physical exam

During seizure: rhythmic movements, gaze deviation, automatisms, postictal Todd paralysis (focal weakness lasting minutes-hours)
Postictal confusion, somnolence (after generalized seizure)
Lateral tongue bite (highly specific for seizure vs syncope)
Skin: incontinence, abrasions

Classic findings

Witnessed rhythmic convulsions + postictal confusion + lateral tongue bite + urinary incontinence.

Differential diagnosis

Syncope — Brief LOC, pallor, diaphoresis, rapid recovery; convulsive syncope can mimic seizure but lacks prolonged postictal state
Psychogenic non-epileptic seizures (PNES) — Asynchronous limb movements, eyes closed, pelvic thrusting, side-to-side head movement, lack of postictal confusion; video-EEG diagnostic
TIA / stroke — Typically negative symptoms (weakness, sensory loss); seizures usually positive (movements, paresthesias)
Migraine with aura — Slower march of symptoms over minutes; visual scintillations, headache follows
Cataplexy / narcolepsy — Sudden loss of muscle tone with preserved consciousness, triggered by emotion
Movement disorders (tics, tremor) — Stereotyped movements with retained awareness
Sleep disorders (REM behavior disorder, parasomnias) — Occur during sleep, video-EEG distinguishes

Diagnostic workup

Diagnostic criteria

Clinical event + EEG abnormality (interictal spikes or ictal pattern) supports epilepsy. ILAE definition of epilepsy: ≥2 unprovoked seizures >24 h apart OR ≥1 with ≥60% recurrence risk.

Labs

Fingerstick glucose, BMP (sodium, calcium, magnesium), CBC, LFTs
Toxicology screen, ethanol level
Pregnancy test in women of childbearing age
Prolactin elevated 10-20 min after generalized seizure (not absence or PNES) — limited utility now
Lumbar puncture if fever or meningitis suspected (after imaging)

Imaging

Non-contrast head CT in ED (acute structural lesion: hemorrhage, mass, stroke)
MRI brain with epilepsy protocol (thin coronal cuts through hippocampus) — for new-onset unprovoked seizures, focal features, or refractory epilepsy
EEG — standard initial (within 24-48 h boosts yield); sleep-deprived or prolonged EEG, video-EEG monitoring for diagnostic uncertainty or surgical workup

Diagnostic algorithm

Seizure Type	Awareness	Classic Features	First-Line AED
Focal aware	Preserved	Motor, sensory, autonomic, psychic symptoms	Levetiracetam, lamotrigine
Focal impaired awareness	Impaired	Automatisms, behavioral arrest	Levetiracetam, oxcarbazepine
Generalized tonic-clonic	Lost	Tonic stiffen → clonic jerks → postictal	Valproate, levetiracetam, lamotrigine
Absence	Brief loss	3 Hz spike-wave EEG, staring, no postictal	Ethosuximide, valproate
Myoclonic	Preserved	Brief shock-like jerks (JME morning jerks)	Valproate, levetiracetam
Atonic	May be impaired	Sudden tone loss, falls	Valproate, lamotrigine

ILAE 2017 seizure classification and first-line treatment.

Treatment

First-line

Acute single seizure: ensure airway, position on side, do NOT restrain or place objects in mouth; time the seizure
Antiepileptic — levetiracetam (1500-3000 mg/day) is broad-spectrum first-line for focal and generalized, lamotrigine (titrate slowly), valproate (avoid in women of childbearing potential — neural tube defects, reduced offspring IQ, autism risk)
Focal seizures: levetiracetam, lacosamide, oxcarbazepine, carbamazepine, lamotrigine
Generalized tonic-clonic: levetiracetam, valproate, lamotrigine, topiramate
Absence seizures: ethosuximide (first-line), valproate, lamotrigine
Myoclonic: valproate, levetiracetam, lamotrigine (can worsen myoclonus in some patients)
Treat reversible cause if provoked seizure — typically no chronic AED needed

Second-line / adjunct

If breakthrough seizures: optimize first AED dose, then switch or add second agent
Refractory epilepsy (failure of 2 appropriate AEDs at adequate dose): refer to epilepsy center
Surgical options: temporal lobectomy (for mesial temporal sclerosis), focal cortical resection, laser ablation, corpus callosotomy for drop attacks
Neuromodulation: vagus nerve stimulator, responsive neurostimulation (RNS), deep brain stimulation
Ketogenic diet (especially pediatric refractory epilepsy)
Counseling: driving restrictions (state-specific; typically 3-12 months seizure-free), safety (no swimming alone, careful with heights/machinery), SUDEP awareness

Complications

Status epilepticus (see separate entry)
Injury: tongue bite, falls, fractures, burns
Sudden Unexpected Death in Epilepsy (SUDEP) — risk ~1/1000 patient-years, higher in poorly controlled epilepsy and during sleep
Cognitive impairment, depression, anxiety (epilepsy comorbidities)
Driving restrictions, vocational impact
Medication side effects: valproate (weight gain, alopecia, hepatotoxicity, teratogenicity), lamotrigine (Stevens-Johnson syndrome), phenytoin (gingival hyperplasia, ataxia)
Pregnancy: valproate is the most teratogenic; lamotrigine and levetiracetam preferred

PANCE pearls

First unprovoked seizure does not automatically equal epilepsy — recurrence risk after first seizure ~30-50% over 2 years.
Lateral tongue bite is highly specific for generalized tonic-clonic seizure (tip-of-tongue bite occurs in syncope).
Postictal Todd paralysis can mimic stroke — resolves over minutes to hours; check old records and consider imaging if first event.
Ethosuximide treats absence ONLY (not generalized tonic-clonic). Valproate covers both.
Avoid valproate in women of childbearing potential when possible — neural tube defects, autism, IQ reduction. Folic acid 1-5 mg/day for women on any AED.

References

ILAE 2014 — ILAE Official Report: A Practical Clinical Definition of Epilepsy (Fisher et al., Epilepsia 2014)
ILAE 2017 — Operational Classification of Seizure Types and Epilepsies (Fisher, Cross, French et al., Epilepsia 2017)
AAN 2018 — Evidence-Based Guideline: Management of an Unprovoked First Seizure in Adults (Krumholz et al., Neurology 2015) — reaffirmed
AES 2016 — Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus (Glauser et al., Epilepsy Currents 2016)

Practice Neurology questions on FirstPassPA

Turn this outline into retention. 3,500+ board-style questions with an AI tutor that explains every answer — free to start, no card required.

Start studying free → Browse all 514 diagnoses

Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants.