Seizure

Background

Types

1. Simple (consciousness not impaired)
2. Complex (consciousness necessarily impaired)
3. Generalized (diffuse brain overactivity)
   1. Tonic-clonic, tonic, clonic, myoclonic
   2. Absence
   3. Atonic
4. Partial (specific area in brain affected)
   1. Partial seizures with secondary generalization

Precipitants (known seizure disorder)

1. Medication noncompliance
2. Sleep deprivation
3. Infection
4. Electrolyte disturbance
5. ETOH or substance withdrawal
6. Substance abuse

Causes (First-Time Seizure)

1. Idiopathic
2. Trauma (recent or remote)
3. Intracranial hemorrhage (subdural, epidural, subarachnoid, intraparenchymal)
4. Structural CNS abnormalities
   1. Vascular lesion (aneurysm, AVM)
   2. Mass lesions (primary or metastatic neoplasms)
   3. Degenerative neurologic diseases
   4. Congenital brain abnormalities
5. Infection (meningitis, encephalitis, abscess)
6. Metabolic disturbances
   1. Hypoglycemia or hyperglycemia
   2. Hyponatremia or hypernatremia
   3. Hyperosmolar states
   4. Uremia
   5. Hepatic failure
   6. Hypocalcemia, hypomagnesemia (rare)
7. Toxins and drugs
   1. Cocaine, lidocaine
   2. Antidepressants
   3. Theophylline
   4. Alcohol withdrawal
   5. Drug withdrawal
8. Eclampsia of pregnancy (may occur up to 8wks postpartum)
9. Hypertensive encephalopathy
10. Anoxic-ischemic injury (cardiac arrest, severe hypoxemia)

Diagnosis

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

Differential Diagnosis

• Syncope
• Pseudoseizures
• Meningitis
• Encephalitis
• Intracranial Hemorrhage
• Hyperventilation syndrome
• Migraine headache
• Movement disorders
• Narcolepsy/cataplexy

Diagnosis

• Abrupt onset
• Brief duratoin (typically <2min)
• AMS
• Purposeless activity
• Unprovoked
• Postictal state

Work-Up

Known Seizure Disorder

1. Glucose
2. Pregnancy test
3. Anticonvulsant levels

First-Time Seizure

1. Glucose
2. CBC
3. Chemistry
4. Pregnancy test
5. Utox
6. Head CT
7. LP (if SAH or meningitis/encephalitis is suspected)

Indications for Head CT

• 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 on side 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

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

No IV

1. Midazolam IM 0.2mg/kg OR
2. Diazepam PR 0.5-1.0mg/kg (up to 20mg)

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

First-Time Seizure

• No treatment necessary if pt has:
  • 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

HIV

DDX

1. Mass lesion
   1. Toxoplasmosis
   2. Lymphoma
2. Meningitis/encephalitis
   1. Cryptococcal
   2. Bacterial/aseptic
   3. Herpes zoster
   4. CMV
3. HIV encephalopathy/AIDS dementia complex
4. Progressive multifocal leukoencephalopathy
5. CNS TB
6. Cysticercosis
7. Neurosyphilis

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) with neuro follow up
• Status epilepticus
  • Admit ICU

See Also

• Seizure Levels and Reloading
• Seizure (Peds)
• Febrile Seizure
• Anticonvulsants

Source

Tintinalli - Seizures