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
- Epileptic seizure
- First-time seizure
- Seizure with known seizure disorder
- Status epilepticus
- Temporal lobe epilepsy
- Non-compliance with anti-epileptic medications
- Hyponatremia
- INH toxicity
- Non-epileptic seizure
- Meningitis
- Encephalitis
- Brain abscess
- Intracranial hemorrhage
- Alcohol withdrawal
- Benzodiazepine withdrawal
- Barbiturate withdrawal
- Baclofen withdrawal
- Metabolic abnormalities: hyponatremia, hypernatremia, hypocalcemia, hypomagnesemia, hypoglycemia, hyperglycemia, hepatic failure, uremia
- Eclampsia
- Neurocysticercosis
- Posterior reversible encephalopathy syndrome
- Impact seizure (head trauma)
- Acute hydrocephalus
- Arteriovenous malformation
- Seizure with VP shunt
- Toxic ingestion (amphetamines, anticholinergics, cocaine, INH, organophosphates, TCA, salicylates, lithium, phenothiazines, bupropion, camphor, clozapine, cyclosporine, fluoroquinolones, imipenem, lead, lidocaine, metronidazole, synthetic cannabinoids, theophylline, Starfruit)
- Psychogenic nonepileptic seizure (pseudoseizure)
- Intracranial mass
- Syncope
- Hyperventilation syndrome
- Migraine headache
- Movement disorders
- Narcolepsy/cataplexy
- Post-hypoxic myoclonus (Status myoclonicus)
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
- First-Line
- Lorazepam 2mg IV (up to 0.1mg/kg) OR diazepam 5-10mg IV (up to 0.15mg/kg); AND
- Phenytoin 20-30mg/kg at 50mg/min OR fosphenytoin 20-30mg/kg/PE at 150mg/min
- Phenytoin/fosphenytoin contraindicated in pts w/ 2nd or 3rd degree AV block
- Phenytoin may cause hypotension due to propylene glycol diluent
- Fosphenytoin may be given IM
- Refractory
- Valproic acid 20-40mg/kg at 5mg/kg/min OR
- Phenobarbital 20mg/kg at 50-75mg/min (be prepared to intubate) OR
- Propofol 2-5mg/kg, then infusion of 2-10mg/kg/hr OR
- Midazolam 0.2mg/kg then inusion of 0.05-2mg/kg/hr OR
- Ketamine 1.5mg/kg then 0.01-0.05mg/kg/hr
- Contraindicated in pts w/ intracranial masses
- First-Line
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
- ↑ 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.
- ↑ Epilepsia 2015; 56:1515-1523.
- ↑ 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.
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 7.0 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
- ↑ Krumholz A, et al. Evidence-based guideline: Management of an unprovoked first seizure in adults. Neurology 2015; 84(16):1705-1713.