First-time seizure


Seizure Types

Classification is based on the international classification from 1981[1]; More recent terms suggested by the ILAE (International League Against Epilepsy) task Force.[2]

Focal seizures

(Older term: partial seizures)

  • Without impairment in consciousness– (AKA Simple partial seizures)
    • With motor signs (ex. facial twiching or rhythmic ipsilateral extremity movements)
    • With sensory symptoms (ex. tingling or pereiving a certain smell)
    • With autonomic symptoms or signs (ex. tachycardia or diaphoresis)
    • With psychic symptoms (including aura, ex. sense of déjà-vu)
  • With impairment in consciousness - (AKA Complex Partial Seizures--Older terms: temporal lobe or psychomotor seizures)
    • Simple partial onset, followed by impairment of consciousness
    • With impairment of consciousness at onset
  • Focal seizures evolving to secondarily generalized seizures
    • Simple partial seizures evolving to generalized seizures
    • Complex partial seizures evolving to generalized seizures
    • Simple partial seizures evolving to complex partial seizures evolving to generalized seizures

Generalized seizures

  • Absence seizures (Older term: petit mal; brief dissociative states without postural changes)
    • Typical absence seizures
    • Atypical absence seizures
  • Myoclonic seizure (violent muscle contractions)
  • Clonic seizures (rhythmic jerking)
  • Tonic seizures (stiffening)
  • Tonic–clonic seizures (Older term: grand mal)
  • Atonic seizures (loss of muscle tone)


  • Sudden Unexpected Death in Epilepsy
  • Generalized tonic-clonic seizure is the major risk factor for SUDEP, and seizure freedom is strongly associated with decreased risk
    • Annual incidence of SUDEP in children is 1 in 4500
    • Incidence in adults is 1 in 1000

Clinical Features

  • Abrupt onset, may be unprovoked
  • Brief duration (typically <2min)
  • AMS
  • Jerking of limbs
  • Postictal drowsiness/confusion
  • Todd paralysis
  • Lateral tongue biting - 100% specificity

Differential Diagnosis

Causes of first-time seizure




Indications for Head CT due to Seizure[5]

  • If patient has returned to a normal baseline:
    1. When feasible, perform a neuroimaging of the brain in the ED on patients with a first-time seizure
    2. Deferred outpatient neuroimaging may be used when reliable follow-up is available


Seizure Precautions

  • Protect patient from injury
    • If possible, place patient in left lateral position to reduce risk of aspiration
    • Do not place bite block!
  • Jaw thrust, a NPA and oxygen may be required
  • An IV line should be placed


  • Benzodiazepine (Initial treatment of choice)[6]
    • Midazolam IM 10 mg (> 40 kg), 5mg (13-40 kg), or 0.2 mg/kg[7]
      • May also be given IN at 0.2 mg/kg, max 10 mg
      • OR buccal at 0.3 mg/kg, max 10 mg
    • Lorazepam IV 4 mg or 0.1 mg/kg; may repeat one dose[8]
    • Diazepam IV 0.15-0.2 mg/kg (up to 10 mg); may repeat one dose or PR 0.2-0.5 mg/kg (up to 20 mg) once [9]
  • Secondary medications
    • ESETT trial[10] compared second line antiseizure medications and they all are equally efficacious. Therefore may be best to use the one with least side effects [11] which is Levetiracetam
    • Levetiracetam IV 60 mg/kg, max 4500 mg/dose, or 1500 mg oral load (preferred in pregnancy)
    • Phenytoin IV 18 mg/kg at ≤ 50 mg/min
    • Fosphenytoin IV 20-30 mg/kg at 150 mg/min (may also be given IM)
      • Contraindicated in pts w/ 2nd or 3rd degree AV block
      • Avoid phenytoin or fosphenytoin in suspected toxicology case due to sodium channel blockade
    • Valproic acid IV 20-40 mg/kg at 5 mg/kg/min, max 3000 mg (avoid in pregnancy)
  • Refractory medications
    • Propofol 2-5mg/kg, then infusion of 2-10mg/kg/hr OR
    • Midazolam 0.2mg/kg, then infusion of 0.05-2mg/kg/hr OR
    • Ketamine loading dose 0.5 to 3 mg/kg, followed by infusion of 0.3 to 4 mg/kg/hr[12]
    • Lacosamide IV 400 mg IV loading dose over 15 min, then maintenance dose of 200 mg q12hrs PO/IV[13]
    • Phenobarbital IV 15-20 mg/kg at 50-75 mg/min[14]
      • Then continuous infusion at 0.5-4.0 mg/kg/hr
      • Dose adjusted to suppression-burst pattern on continuous EEG
    • Consider consulting anesthesia for inhaled anesthetics (potent anticonvulsants)[15]
  • Others

Other Considerations


Several states have mandatory DMV reporting requirements

  • No anticonvulsant treatment necessary if patient has[16]:
    • Normal neuro exam
    • No acute or chronic medical comorbidities
    • Normal diagnostic testing (including normal imaging)
    • Normal mental status
  • Treatment generally indicated if seizure due to an identifiable neurologic condition


  • Discharge (no need to start antiepileptic[16]) with neuro follow up
    • Risk for recurrent seizure is greatest within the first 2 years after a first seizure (21%-45%)

See Also

External Links

ACEP Clinical Policy on Seizure


  1. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. From the Commission on Classification and Terminology of the International League Against Epilepsy. Epilepsia 1981; 22:489.
  2. Epilepsia 2015; 56:1515-1523.
  3. Harden C et al. American Academy of Neurology and the American Epilepsy Society. Practice guideline summary: Sudden unexpected death in epilepsy incidence rates and risk factors. Neurology April 25, 2017 vol. 88 no. 17 1674-1680.
  4. Ebru Apaydın Doğan, Ali Ünal, Aslıhan Ünal, Çağla Erdoğan, Clinical utility of serum lactate levels for differential diagnosis of generalized tonic–clonic seizures from psychogenic nonepileptic seizures and syncope, Epilepsy & Behavior, Volume 75, 2017, Pages 13-17, ISSN 1525-5050, (
  5. ACEP Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with seizures. Ann Emerg Med 2004; 43:605-625
  6. Glauser T, et al. Evidence-based guideline: treatment of convulsive status epilepticus in children and adults: report of the guideline committee of the American Epilepsy Society. Epilepsy Curr. 2016; 16(1):48-61.
  7. McMullan J, Sasson C, Pancioli A, Silbergleit R: Midazolam versus diazepam for the treatment of status epilepticus in children and young adults: A meta-analysis. Acad Emerg Med 2010; 17:575-582
  8. Glauser T, Shinnar S, Gloss D, et al. Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus in Children and Adults: Report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48-61. doi:10.5698/1535-7597-16.1.48
  9. Glauser T, Shinnar S, Gloss D, et al. Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus in Children and Adults: Report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48-61. doi:10.5698/1535-7597-16.1.48
  10. Kapur J, Elm J, Chamberlain J, et al. Randomized Trial of Three Anticonvulsant Medications for Status Epilepticus. N Engl J Med. 2019;381(22):2103-2113. doi:10.1056/NEJMoa1905795
  11. PulmCrit- All 2nd line conventional anti-epileptics are equally good… or equally bad?
  12. Legriel S, Oddo M, and Brophy GM. What’s new in refractory status epilepticus? Intensive Care Medicine. 2016:1-4.
  13. Legros B et al. Intravenous lacosamide in refractory seizure clusters and status epilepticus: comparison of 200 and 400 mg loading doses. Neurocrit Care. 2014 Jun;20(3):484-8.
  14. Pugin D et al. Is pentobarbital safe and efficacious in the treatment of super-refractory status epilepticus: a cohort study. Critical Care 2014. DOI: 10.1186/cc13883.
  15. Mirsattari SM et al. Treatment of refractory status epilepticus with inhalational anesthetic agents isoflurane and desflurane. Arch Neurol. 2004 Aug;61(8):1254-9.
  16. 16.0 16.1 Krumholz A, et al. Evidence-based guideline: Management of an unprovoked first seizure in adults. Neurology 2015; 84(16):1705-1713.