CORE EM: Approach to Adult First Time Seizure in the ED

Definition: Excessive, abnormal cortical neuronal activity resulting in a variety of physical symptoms.

• Provoked seizure: An acute symptomatic seizure that occurs at the time of or within 7 days of an acute neurologic, systemic, metabolic, or toxic insult (Huff 2014).
• Unprovoked seizure: A seizure occurring in the absence of acute precipitating factors and includes remote symptomatic seizures, as well as seizures that are not established to have a cause.

Seizure classification:

Questions that can help guide your ED management decisions

• Is the patient back to his baseline neurological status?
  • Get collateral information to ensure an accurate answer
• Is this a first time seizure?
  • Be aware that 50% of “first time seizures” have had prior events
  • Consider Syncope!
• Is the seizure provoked or unprovoked?

Differential Diagnosis

Non-Contrast Head CT (NCHCT) (Rosen’s 2014)

• Unprovoked, back at baseline: NCHCT not indicated
• Provoked or unprovoked, NOT at baseline: Obtain NCHCT
  • NCHCT abnormal in up to 80% of patients with focal neurological deficit after seizure (Harden 2007)
• Provoked and back at baseline: 
  • No definitive recommendations
  • NCHCT unlikely to have high-yield
  • If provoking factor addressed and patient can reliably follow up, may consider outpatient imaging

Electroencephalogram (EEG)

• Provoked or unprovoked, NOT at baseline = Emergent EEG
  • Concern for status (nonconvulsive) epilepticus
  • Mortality rates estimated to be as high as 40% (Tardy 1995) 
• If patient returns to baseline, EEG can be deferred to outpatient

Electrocardiogram

• Always obtain an ECG in first time seizure patients
• The challenge: Significant overlap in presentation with syncope often having myoclonic or tonic jerks (12-75%) due to cerebral hypoperfusion (Bergfeldt 2003)
• The importance: Misdiagnosing syncope as seizure can lead to application of incorrect treatment and, thus mortality and morbidity
• Can’t miss EKG findings (Bergfeldt 2003)
  • Wolff-Parkinson-White syndrome
  • Prolonged QT interval (especially in younger patients)
  • Brugada syndrome: RBBB pattern with STE in V1-V3
  • Hypertrophic cardiomyopathy
  • Arrhythmogenic RV dysplasia: Negative T waves in V1-V3 with or without epsilon waves
  • Bi/tri fascicular blocks or undetermined intraventricular conduction abnormalities
  • High degree AV blocks

Lumbar Puncture

• Indicated if there’s a concern for a CNS infection (i.e. meningitis, encephalitis)
• Lower threshold to LP if patient is immunocompromised (increased rate of CNS toxoplasmosis, CNS abscess etc)
• Provoked or unprovoked
  • At baseline: No LP
  • NOT at baseline: Obtain LP

Starting AEDs

• Current best literature does not uniformly recommend starting AEDs after a first time seizure (Knake 2009)
• Early treatment does not seem to provide protection from future seizures.

Take home points:

• It is critical to determine if the event was a seizure or syncope. Look for a post-ictal period and get an EKG in all patients
• Review the differential for seizure in all patients, particularly those with a 1st time seizure. Consider vital sign abnormalities, toxic/metabolic, CNS and infectious causes
• In 1st time seizures, always carefully consider whether the seizure was provoked or unprovoked and whether the patient is back at his baseline as this can drastically effect management.
• There is no specific testing that is required in all patients with a 1st time seizure. Testing is based on your history and physical examination

Read More

EM Lyceum: Seizure, Answers

LITFL: Seizures

EM Docs: Treatment of seizures in the Emergency room: pearls and pitfalls

References

Bergfeldt, L. Differential diagnosis of cardiogenic syncope and seizure disorder. Heart 2003; 89(3): 353-358. PMID: 1767616

Harden CL et al. Reassessment: neuroimaging in the emergency patient presenting with seizure (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2007; 69 (18): 1772-1780. PMID 17967993

Huff JS et al. Clinical policy: critical issues in the evaluation and management of adult patients presenting to the emergency department with seizures. Ann Emerg Med 2014; 63 (4): 437-447.e415. PMID 24655445

Knake S, et al. Status epilepticus: a critical review. Epilepsy Behav 2009; 15 (1): 10-14. PMID 19236943

McMullan J et al. Seizure disorders, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2010, (Ch) 102: p 1375-1385.

Raskin NH et al. Neurologic Disorders in Renal Failure. NEJM 1976; 294 (3): 143-148. PMID 1105188

Tardy B et al. Adult first generalized seizure: etiology, biological tests, EEG, CT scan, in an ED. Am J Emerg Med 1995; 13 (1): 1-5. PMID: 7832926