Seizure

posted in Neurology, Neurosurgery on by
Cardinal Presentations

This post is part of a series called “Cardinal Presentations”, based on Rosen’s Emergency Medicine (8th edition).

Definition

Seizure
Pathologic neuronal activation leading to abnormal function
Epilepsy
Recurrent unprovoked seizures

Classification

  • Cause
    • Primary: Unprovoked
    • Secondary: Provoked, caused by trauma, illness, intoxication, metabolic disturbances, etc.
  • Effect on mentation
    • Generalized: involvement of both hemispheres with associated loss of consciousness (tonic-clonic, absence, atonic, myoclonic)
    • Focal: Involving single hemisphere with preserved level of consciousness
  • Status epilepticus
    • Witnessed convulsions lasting >5min
    • Recurrent seizure without recovery from postictal period

Causes of Seizures

Causes of Seizures

Management of Seizures

Management of Seizures

Medications for Treatment of Seizures

Medication Dose (adult) Dose (peds) Comment
1st Line
Lorazepam 4mg IV <13kg: 0.1mg/kg (max 2mg)
13-39kg: 2mg

>39kg: 4mg		 Repeat in 10min
Midazolam 10mg IM 0.2mg/kg IM (max 5mg) Repeat in 10min
Midazolam 10mg buccal 0.5mg/kg buccal (max 5mg) Repeat in 10min
2nd Line
Fosphenytoin 20mg PE/kg IV    
Phenytoin 20mg/kg IV   May cause hypotension
3rd Line
Midazolam 0.05-2mg/kg/hr    
Propofol 1-2mg/kg bolus then 20-200mcg/kg/min    
Pentobarbital 5-15mg/kg bolus then 0.5-5mg/kg/hr    
Special Conditions
Glucose 50mL D50/W   Hypoglycemia
MgSO4 6g IV over 15min   Eclampsia (20wks gestation to 6wks post-partum)
Pyridoxine 0.5g/min until seizures stop, max 5g   INH ingestion
3% saline 100-200mL over 1-2h   Confirmed hyponatremia

History

Points suggestive of seizure over alternative process
Abrupt onset
Duration < 120s
LOC
Purposeless activity: automatisms, tonic-clonic
Provocation: fever in children, substance withdrawal
Postictal state
Retrograde amnesia
Incontinence, oral trauma (buccal maceration, tongue laceration)
Rapidly resolving lactic acidosis
Important historical points for patients with seizure history
Recent illness
Medications (adherence, changes, interactions)
Substance use
Ictogenic factors
Recent/remote head trauma
Developmental abnormalities
Substance use
Sleep deprivation
Pregnancy

Key Physical Examination Findings

  • Vital sign abnormalities persisting beyond immediate postictal state (may suggest drug/toxin exposure, CNS lesion)
  • Nuchal rigidity
  • Signs of IVDA
  • Sequela

    • Head trauma
    • Tongue laceration
    • Shoulder dislocation (posterior)
  • Neurological exam

    • Stroke
    • Elevated ICP
    • Failure to note improvement in postictal confusion (encephalopathy, subclinical seizures)

Labs

  • Glucose
  • BMP (Na, Ca, Mg)
  • AED levels
  • CBC (leukocytosis and bandemia common post-seizure)
  • CSF
  • B-hCG
  • LFT (hepatic dysfunction, alcoholic hepatitis)
  • Lactate (rapidly resolves on repeat)

Indications for Imaging

  • New seizures
  • History of trauma
  • History of malignancy
  • Immunocompromised
  • Headache
  • Anti-coagulation
  • Focal neurological exam
  • Persistent AMS

References

  1. McMullan, J., Davitt, A., & Pollack, C. (2013). Seizures. In Rosen’s Emergency Medicine – Concepts and Clinical Practice (8th ed., Vol. 1, pp. 156-161). Elsevier Health Sciences
  2. WikEM: Seizure