Seizure (first-time)MANAGEMENT

NEUROLOGICAL PRESENTATIONS · 12 SECTIONS

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480 items

☷ Legend

01Approach to the Critical Patient/attcp72

Immediate priorities

›Stabilization priorities

›Airway protection triggers

›Persistent loss of protective reflexes

›Recurrent convulsions without recovery

›Refractory hypoxaemia or hypercapnia

›Breathing support

›SpO2 target 94-98%

›Capnography for hypoventilation concern

›Circulation support

›IV access x2

›Cardiac monitoring for dysrhythmia

›Rapid reversible causes

›Point-of-care glucose

›Naloxone if opioid toxidrome

›Ongoing seizure algorithm

›Status epilepticus definition

›Convulsive activity 5 minutes or longer

›Recurrent seizures without baseline recovery

›First-line benzodiazepine (Class I)

›Lorazepam IV 0.1 mg/kg

›Typical adult dose 4 mg

›Repeat once after 5 minutes if ongoing

›Midazolam IM 10 mg

›Alternative when no IV access

›Repeat 10 mg once after 10 minutes if ongoing

›Second-line antiseizure loading (Class I)

›Levetiracetam IV 60 mg/kg

›Maximum 4500 mg

›Infusion 10-15 minutes

›Fosphenytoin IV 20 mg PE/kg

›Maximum 1500 mg PE

›Infusion rate up to 150 mg PE/min

›Valproate IV 40 mg/kg

›Maximum 3000 mg

›Avoid in pregnancy and significant hepatic disease

›Refractory convulsive status pathway

›ICU escalation trigger

›Persistent convulsions after benzodiazepine plus one second-line agent

›Persistent coma or ventilatory failure

›Continuous infusion options

›Propofol infusion with ventilatory support

›Midazolam infusion with ventilatory support

›Time-critical “must not miss” conditions

›Intracranial haemorrhage

›Thunderclap headache

›Anticoagulant use

›CNS infection

›Fever

›Neck stiffness

›Eclampsia

›Pregnancy or postpartum

›Hypertension with neurologic symptoms

›Toxic ingestion or withdrawal

›Alcohol withdrawal features

›Sympathomimetic toxidrome

Immediate monitoring targets

›Monitoring and targets

›Neurologic trajectory

›Time to return to baseline

›Persistent focal deficit

›Vitals and supportive care

›Temperature trend

›SBP target appropriate for suspected ICH pathway

›Injury screening

›Head trauma concern

›Tongue laceration and aspiration risk

PEARLS

›High-yield bedside rules

›Ongoing convulsive activity at 5 minutes equals status pathway

›Early benzodiazepine improves seizure termination likelihood

›Delay increases ICU and intubation risk

›First-time seizure equals “provoked vs unprovoked” decision point

›Provoked seizure recurrence risk falls after cause corrected

›Unprovoked seizure recurrence risk persists and guides follow-up and therapy

02History/hx52

Event characterization

›Spell features

›Witness description

›Sudden onset

›Rhythmic tonic-clonic activity

›Focal onset signs

›Head or eye deviation

›Unilateral jerking

›Duration and recovery

›Total duration estimate

›Postictal confusion duration

›Seizure markers

›Lateral tongue bite

›Urinary incontinence

›Syncope markers

›Prodrome with lightheadedness

›Triggered by standing or pain

›Rapid recovery without confusion

Precipitants and provocation

›Provoked causes

›Sleep deprivation

›Last sleep duration

›Shift work or jet lag

›Substance and withdrawal

›Alcohol use pattern

›Benzodiazepine cessation

›Stimulants or cocaine

›Metabolic and systemic stressors

›Vomiting and poor intake

›Recent diarrhoea

›Medication triggers

›Bupropion dose change

›Tramadol exposure

›Antipsychotic initiation

Risk factors for intracranial pathology

›Structural and vascular risks

›Prior stroke or brain tumour

›Known intracranial lesion

›Prior neurosurgery

›Recent head trauma

›Fall with head strike

›Anticoagulant use

›CNS infection risks

›Immunocompromised state

›Recent travel or sick contacts

Prior neurologic history

›Baseline neurologic context

›Prior unrecognised seizures

›Déjà vu episodes

›Brief behavioural arrest

›Developmental and childhood history

›Febrile seizures

›Known epilepsy in childhood

›Family history

›First-degree relative epilepsy

›Sudden unexplained death history

03Physical Exam/exam33

Neurologic exam

›Neurologic findings

›Mental status

›Orientation and attention

›Persistent confusion beyond expected postictal window

›Focal deficits

›Unilateral weakness

›Aphasia or neglect

›Meningeal signs

›Nuchal rigidity

›Photophobia

›Todd paralysis

›Focal weakness after seizure

›Progressive resolution over hours

General exam and injuries

›System exam priorities

›Airway and aspiration indicators

›Hypoxaemia

›Coarse breath sounds

›Trauma survey

›Scalp haematoma

›Oral trauma and tongue bite

›Toxidrome assessment

›Pupillary size

›Diaphoresis or agitation

›Fever and infection screen

›Temperature elevation

›Rash or petechiae

PITFALLS

›Common misses

›Persistent altered mental status labelled “postictal” without time trend

›Nonconvulsive status epilepticus possibility

›Toxic-metabolic encephalopathy possibility

›Convulsive syncope mislabelled as seizure

›Arrhythmia risk if exertional syncope or palpitations

›Need ECG in nearly all first-event presentations

04Differential Diagnosis/ddx30

Life-threatening and time-sensitive

›Dangerous diagnoses

›Intracranial haemorrhage (ICD-10 I61.-, I60.-)

›Severe headache or anticoagulant use

›Focal deficit or decreased level of consciousness

›CNS infection (ICD-10 G00.-, G04.-)

›Fever and meningismus

›Immunocompromised state

›Metabolic derangement (ICD-10 E16.2, E87.1, E83.51)

›Hypoglycaemia

›Hyponatraemia

›Hypocalcaemia

›Toxic ingestion or withdrawal (ICD-10 T36-T50, F10.23, F13.23)

›Alcohol withdrawal

›Drug intoxication

›Eclampsia (ICD-10 O15.-)

›Pregnancy or postpartum

›Hypertension and proteinuria context

Mimics and alternate explanations

›Non-epileptic events

›Syncope (ICD-10 R55)

›Prodrome and posture trigger

›Rapid recovery without postictal state

›Psychogenic nonepileptic seizures (SNOMED CT concept)

›Prolonged fluctuating course

›Eyes closed and asynchronous movements

›Migraine with brainstem aura (ICD-10 G43.-)

›Visual aura and headache pattern

›Recurrent stereotyped episodes

›Transient ischaemic attack (ICD-10 G45.-)

›Negative symptoms predominance

›Vascular risk profile

05Laboratory Tests/lt32

Core tests for first-time seizure

›Baseline laboratory evaluation

›Glucose and electrolytes

›Point-of-care glucose for immediate exclusion of hypoglycaemia

›Sodium for hyponatraemia-related seizure risk

›Calcium for hypocalcaemia-related seizure risk

›Magnesium for hypomagnesaemia-related seizure risk

›Renal and hepatic function

›Creatinine for drug dosing and uraemia

›ALT and AST for hepatic encephalopathy concern

›Pregnancy testing

›Urine or serum beta-hCG for all patients with pregnancy potential

›Eclampsia pathway trigger if positive and hypertensive

Targeted tests by scenario

›Scenario-driven labs

›Infection concern

›Complete blood count for leukocytosis or anaemia

›Blood cultures if sepsis physiology

›Toxicology and withdrawal concern

›Ethanol level for intoxication and withdrawal risk

›Toxicology screen when management changes based on result

›Rhabdomyolysis concern

›Creatine kinase after prolonged convulsion

›Urinalysis for myoglobinuria

›Antiseizure medication exposure

›Drug levels if known antiseizure therapy or suspected overdose

›Acetaminophen and salicylate levels if unknown ingestion

Interpretation and pitfalls

›Lab limitations

›Serum prolactin

›Limited utility for ED rule-out of seizure vs syncope

›Not reliable for psychogenic nonepileptic seizure exclusion

›Mild postictal metabolic changes

›Transient lactic acidosis expected after tonic-clonic seizure

›Leukocytosis may be stress-related without infection

06Diagnostic Tests/dt58

Scoring Systems

›Risk stratification and recurrence concepts

›Provoked vs unprovoked classification

›Acute symptomatic seizure definition

›Occurs in temporal association with acute CNS insult or metabolic/toxic disturbance

›Lower long-term recurrence after correction of trigger

›Unprovoked seizure definition

›No acute trigger identified

›Higher recurrence risk guiding EEG and MRI

›High recurrence risk features after a first unprovoked seizure

›Abnormal EEG with epileptiform discharges

›Increased recurrence risk within 2 years

›Supports earlier antiseizure therapy discussion

›Structural brain lesion on neuroimaging

›Prior stroke, tumour, cortical dysplasia

›Increased recurrence risk

›Prior brain insult history

›Traumatic brain injury with structural change

›CNS infection sequelae

›Nocturnal seizure

›Increased recurrence risk

MRI

›MRI brain role

›Indications

›First unprovoked seizure with normal CT

›Focal onset features or focal deficit

›Preferred protocol

›Epilepsy protocol when available

›Thin slices through temporal lobes

›Limitations

›Not time-critical in most stable first seizures

›Access and scheduling constraints

›Findings of concern

›Mass lesion

›Mesial temporal sclerosis

›Cortical dysplasia

›CT head role in ED

›Immediate CT indications (ACEP Level B/C style)

›New focal neurologic deficit

›Persistent altered mental status

›Head trauma with concern for intracranial injury

›Fever or immunocompromised state with concern for intracranial complication

›Known malignancy

›Anticoagulant use or bleeding diathesis

›CT technique

›Non-contrast CT for haemorrhage and mass effect

›CTA consideration if suspected aneurysmal SAH or vascular lesion based on presentation

›Limitations

›Normal CT does not exclude epilepsy-causing lesions

›Low yield in low-risk, fully recovered, normal exam presentations

Ultrasound (or US)

›Ultrasound adjuncts

›Pregnancy-related evaluation

›Bedside obstetric US if pregnant with abdominal pain or bleeding

›Fetal assessment support for maternal stabilisation priorities

›Trauma and aspiration evaluation

›Lung US for aspiration pneumonitis pattern when hypoxaemic

›FAST if trauma with haemodynamic instability

›Cardiac evaluation in syncope mimic

›Focused cardiac US for gross cardiomyopathy if exertional collapse

›IVC assessment adjunct, not diagnostic

07Disposition/dispo29

Admission and higher level of care

›Admission criteria

›Status epilepticus or recurrent seizures

›Ongoing seizure activity

›Multiple seizures in 24 hours

›Persistent neurologic abnormality

›Focal deficit not resolving

›Prolonged altered mental status

›Serious underlying cause suspected or confirmed

›Intracranial haemorrhage or mass

›CNS infection

›Significant metabolic derangement

›Sodium markedly low

›Glucose unstable

›Unsafe discharge context

›No responsible supervision

›Inability to arrange urgent follow-up

Discharge criteria and follow-up

›Discharge pathway for low-risk first seizure

›Clinical stability

›Return to baseline mental status

›Normal neurologic exam

›Workup reassuring

›No emergent cause identified

›ECG without high-risk dysrhythmia

›Follow-up plan

›Neurology referral arranged

›EEG arranged within days when feasible

›Safety counselling completed

›Driving and high-risk activity restrictions

›Return precautions provided

08Treatment/t71

Active seizure and status epilepticus

›Convulsive seizure termination

›Benzodiazepine first-line (Class I)

›Lorazepam IV 0.1 mg/kg

›Typical adult dose 4 mg

›Repeat once after 5 minutes if ongoing

›Respiratory depression monitoring

›Midazolam IM 10 mg

›No IV access option

›Repeat 10 mg once after 10 minutes if ongoing

›Consider IN route if IM not feasible

›Second-line loading (Class I)

›Levetiracetam IV 60 mg/kg

›Maximum 4500 mg

›Infuse over 10-15 minutes

›Minimal haemodynamic effects

›Fosphenytoin IV 20 mg PE/kg

›Maximum 1500 mg PE

›Infuse up to 150 mg PE/min

›Cardiac monitoring during infusion

›Valproate IV 40 mg/kg

›Maximum 3000 mg

›Avoid in pregnancy

›Avoid in severe hepatic dysfunction

›Refractory convulsive status

›Intubation and ICU pathway trigger

›Persistent convulsions after benzodiazepine plus one second-line agent

›Worsening gas exchange or haemodynamic instability

›Continuous infusion options

›Propofol

›Initiate infusion with ventilatory support

›Titrate to seizure suppression on EEG

›Hypotension monitoring

›Midazolam

›Initiate infusion with ventilatory support

›Titrate to seizure suppression on EEG

›Tachyphylaxis awareness

First unprovoked seizure long-term therapy decision

›Antiseizure medication initiation considerations

›Factors supporting initiation after first unprovoked seizure

›Abnormal EEG with epileptiform activity

›Structural lesion on MRI or CT

›Prior CNS insult with imaging correlate

›Factors supporting deferral after first unprovoked seizure

›Normal neurologic exam

›Normal imaging and anticipated prompt EEG

›Shared decision elements

›Short-term recurrence reduction with medication

›Limited effect on long-term remission probability

›Common outpatient starter options

›Levetiracetam oral

›500 mg twice daily

›Increase by 500 mg twice daily every 1-2 weeks as needed

›Typical range 1000-3000 mg/day

›Neuropsychiatric adverse effects counselling

›Irritability

›Mood changes

›Lamotrigine oral

›Slow titration required to reduce rash risk

›Not ideal for immediate ED initiation without follow-up structure

Cause-directed therapy

›Provoked seizure management

›Hypoglycaemia

›Dextrose therapy per hypoglycaemia protocol

›Recheck glucose after treatment

›Hyponatraemia with severe symptoms

›Hypertonic saline protocol per sodium severity pathway

›Avoid overly rapid correction

›Alcohol withdrawal

›Benzodiazepine symptom-triggered protocol

›Thiamine prior to glucose when malnourished concern

›CNS infection

›Empiric antimicrobials after cultures when indicated

›Dexamethasone where indicated by meningitis pathway

09Special Populations/sp36

Pregnancy

›Pregnancy-specific priorities

›Eclampsia pathway

›Hypertension and seizure in pregnancy or postpartum as eclampsia until proven otherwise

›Magnesium sulfate therapy

›4 g IV loading dose over 10-15 minutes

›Maintenance 1-2 g/hour infusion

›Respiratory rate and reflex monitoring

›Obstetrics consultation trigger

›Any suspected eclampsia

›Persistent severe-range blood pressure

›Antiseizure medication selection

›Avoid valproate when possible due to teratogenicity

›Benzodiazepines acceptable for emergent seizure termination

›Imaging considerations

›CT head acceptable when maternal life-threatening diagnosis suspected

›MRI preferred for non-urgent structural evaluation

Geriatric

›Older adult considerations

›Higher likelihood of secondary cause

›Stroke and haemorrhage prevalence

›Tumour and subdural risk after falls

›Medication vulnerability

›Increased sedation sensitivity to benzodiazepines

›Polypharmacy interactions and renal dosing

›Cardiac mimic prevalence

›Higher arrhythmia risk requiring ECG and monitoring

›Orthostatic evaluation when syncope suspected

Pediatrics

›Pediatric first seizure approach

›Age-specific differentials

›Febrile seizure in appropriate age range

›Inborn errors or metabolic triggers in infants

›Weight-based emergency dosing

›Lorazepam IV 0.1 mg/kg

›Levetiracetam IV 60 mg/kg

›Imaging thresholds

›Lower CT use when rapid return to baseline and normal exam

›CT prioritised with trauma, focal deficits, or persistent altered mental status

10Background/b27

Epidemiology

›Epidemiologic facts

›First seizure frequency

›Common ED presentation across age groups

›Bimodal incidence with peaks in early childhood and older adulthood

›Provoked vs unprovoked distribution

›Significant proportion provoked by reversible metabolic or toxic causes

›Unprovoked seizures carry ongoing recurrence risk

Pathophysiology

›Mechanistic framework

›Seizure definition

›Transient signs or symptoms from abnormal excessive or synchronous neuronal activity

›Classification by focal vs generalised onset

›Provoked seizure biology

›Acute disruption of neuronal stability from metabolic, toxic, infectious, or structural insult

›Risk falls when acute trigger resolves

›Unprovoked seizure biology

›Underlying predisposition from structural lesion or network hyperexcitability

›Recurrence risk influenced by EEG and imaging abnormalities

Therapeutic Considerations

›Treatment principles

›Time dependence in active seizures

›Early benzodiazepine improves termination likelihood

›Prolonged seizures increase neuronal injury risk

›Medication selection tradeoffs

›Levetiracetam favourable interaction profile

›Fosphenytoin useful when focal status suspected but requires cardiac monitoring

›First seizure medication decisions

›Immediate therapy reduces short-term recurrence risk

›Long-term remission rates influenced more by underlying aetiology than immediate medication start

11Patient Discharge Instructions/pdi26

copy discharge instructions

›Discharge instructions

›Activity and safety restrictions

›No driving until cleared under local regulations

›No swimming alone

›No bathing unsupervised

›Avoid ladders, roofs, and heights

›Avoid operating heavy machinery

›Seizure first aid for family

›Side-lying recovery position after convulsion ends

›Remove nearby hazards

›No objects in mouth

›Time the event

›Return to ED immediately

›Seizure lasting 5 minutes or longer

›Repeated seizures without full recovery

›New weakness, confusion, or severe headache

›Fever, stiff neck, or persistent vomiting

›Pregnancy with headache or visual symptoms

›Follow-up plan

›Neurology appointment arranged or requested within 1-2 weeks

›EEG scheduling instructions if not yet completed

›MRI scheduling instructions if recommended

›Trigger reduction

›Sleep regularity

›Avoid binge alcohol and withdrawal

›Avoid recreational drugs

12References/r14

Clinical guidelines and evidence-based sources

›Core guideline sources

›American Epilepsy Society guideline for convulsive status epilepticus pharmacotherapy

›Benzodiazepines as first-line therapy (Class I concept)

›Levetiracetam, fosphenytoin, or valproate as second-line options (Class I/IIa concept)

›International League Against Epilepsy seizure classification framework

›Focal onset vs generalised onset definitions

›Acute symptomatic vs unprovoked seizure conceptual separation

›Emergency medicine decision support themes

›Neuroimaging selection principles for first-time seizure

›Immediate CT for focal deficits, trauma, anticoagulation, persistent altered mental status

›MRI as preferred outpatient structural evaluation for unprovoked seizure

›EEG timing principles

›Early EEG increases yield for epileptiform abnormalities

›EEG supports recurrence risk counselling and treatment decisions

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

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