Seizure

Background

  • Simple (consciousness not impaired)
  • Complex (consciousness necessarily impaired)

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
    • These seizures may be accompanied by automatism (such as lip smacking and chewing, hand wringing, patting and rubbing)
  • 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 (last longer and often include more motor involvement)
  • 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 -> drop attacks)

SUDEP[3]

  • 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

Precipitants (known seizure disorder)

  • Medication noncompliance
  • Sleep deprivation
  • Infection
  • Electrolyte disturbance
  • Substance withdrawal (eg alcohol, BZPs)
  • Substance intoxication

Clinical Features

  • Abrupt onset, unprovoked
  • Brief duratoin (typically <2min)
  • AMS
  • Jerking of limbs
  • Postictal drowsiness/confusion

Differential Diagnosis

Seizure

Diagnosis

Physical

  • Check for:
    • Head / C-spine injuries
    • Tongue/mouth lacs
      • Sides of tongue (true seizure) more often bitten than tip of tongue (pseudoseizure)
    • Posterior shoulder dislocation
    • Focal deficit (Todd paralysis vs CVA)

Work-Up

Known Seizure Disorder

  • Glucose
  • Pregnancy test
  • Anticonvulsant levels

First-Time Seizure

  • Glucose
  • CBC
  • Chemistry
  • Pregnancy test
  • Utox
  • Head CT
  • LP (if SAH or meningitis/encephalitis is suspected)

Indications for Head CT[4]

  • First seizure if age older than 40
  • History of acute head trauma
  • History of malignancy
  • Immunocompromised status
  • Suspect Intracraneal Process
  • History of anticoagulation
  • New focal neurologic deficit
  • Focal onset before generalization
  • Persistently altered mental status

Treatment

Actively Seizing

  • Protect pt from injury
    • If possible place pt in left lateral position to reduce risk of aspiration
    • Do not place bite block
    • Ensure clear airway after seizure stops
  • Most seizures self resolve. If a patient is actively seizing then any benzodiazepine can be used however Lorazepam IM or IV is generally first line[5]

Status Epilepticus

  • Continuous or intermittent seizures >5 min without recovery of consciousness
  • Consider secondary causes of seizure (e.g. hyponatremia, INH overdose, ecclampsia)
  • Consider EEG to rule-out nonconvulsive status
  • Consider prophylactic intubation
  • Meds

No IV

History of Seizure

  • Identify and correct potential precipitants
  • Reload seizure medication if necessary: Seizure Levels and Reloading
    • May use IV vs PO reload at physican discretion[7]

First-Time Seizure

  • No treatment necessary if pt has[7][8]:
    • 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

Special Populations

Neurocysticercosis

  • Seizures are typically controlled by antiepileptic monotherapy

Pregnancy

  • If pregnancy >20wks and <4wks postpartum consider eclampsia
  • Most seizures in pregnancy are not first-time seizures
    • Due to pharmacokinetic drug changes as result of pregnancy or med noncompliance

Disposition

  • Typical seizure with known seizure history, normal w/u
    • Discharge after reload
  • New onset seizure
    • Discharge (no need to start antiepileptic[7]) with neuro follow up
    • Risk for recurrent seizure is greatest within the first 2 years after a first seizure (21%-45%)
  • Status epilepticus
    • Admit ICU

See Also

References

  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. 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
  5. Treiman D, Meyers P, Walton N, et al. A comparison of four treatments for generalized convulsive status epilepticus. New Engl J Med 1998; 339; 792-798
  6. 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
  7. 7.0 7.1 7.2 Clinical Policy:Critical Issues in the Evaluation and Management of Adult Patients Presenting to the ED with Seizures. Annals of EM. April 2014. 63(4);p437-446
  8. Krumholz A, et al. Evidence-based guideline: Management of an unprovoked first seizure in adults. Neurology 2015; 84(16):1705-1713.