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Neurology - Seizures & Epilepsy - Fast Facts | NEJM Resident 360

Seizures

Seizure is a common occurrence in hospitalized medical patients. Patients with preexisting epilepsy often have a lowered seizure threshold when hospitalized due to acute illness, medications used to treat the acute Illness, and/or decreased antiepileptic drug (AED) levels. Decreased AED levels may result from poor compliance or interaction with new medications. Hospitalized patients may also present with new-onset seizure due to metabolic derangements, toxic ingestions, withdrawal from certain drugs (e.g., alcohol, benzodiazepines), infectious etiologies, or intracranial pathologies. Knowing how to manage both acute seizures in the hospital setting and status epilepticus is an important part of your training.

The majority of seizures resolve spontaneously within 2 minutes without medication. However, establishing intravenous (IV) access in these patients is critical in case benzodiazepines (lorazepam 2–4 mg IV or midazolam 0.02 mg/kg IV) is warranted due to prolonged seizure. If no IV access can be established, 10 mg of intramuscular (IM) midazolam or rectal diazepam can be used as alternatives.

For more on the efficacy of IV versus IM midazolam, read a NEJM Journal Watch summary of the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) study.

Workup for New Seizures

• complete neurologic exam

• laboratory analysis (including toxicology screen to look for metabolic, infectious, or toxic causes)

• AED levels in patients with history of epilepsy

• neuroimaging with noncontrast head CT (may also require MRI or electroencephalograph [EEG] monitoring)

• lumbar puncture (LP) if presentation is suggestive of acute infectious process involving the central nervous system; should only be performed after a space-occupying brain lesion has been ruled out with neuroimaging

The American Academy of Neurology and American Epilepsy Society guidelines for workup and management of first seizure, last updated in 2015, can be found here.

The following table lists conditions that can mimic epileptic seizures:

Treatment

Aim treatment at the underlying cause if found. Consider long-term AED treatment in patients for whom the underlying etiology is likely to persist or for prolonged or recurrent seizures.

Information about dosing and target blood levels for common antiepileptic drugs can be found here.

The following table describes factors that affect the choice of antiepileptic drugs in specific patient populations:

Note: Remember to give AEDs to patients on time, without skipping doses (e.g., in patients waiting for long periods in the emergency department). If enteral forms cannot be given, then alternate AEDs with IV forms should be selected with guidance from neurology.

Status Epilepticus

Status epilepticus — a life threatening emergency — is defined as one of the following:

• ≥5 minutes of continuous seizures

• ≥2 discrete seizures without complete recovery of consciousness in between

Management

• Use the ABCD mnemonic:

A: Airway management (often requires intubation)
B: Breathing support with oxygen or mechanical ventilation
C: Circulation with IV access to administer key medications
D: Dextrose (make sure to check blood sugar)

• Patients usually require transfer to an intensive care unit (ICU).

• IV thiamine and dextrose should be considered as treatments for reversible causes of seizure.

• Initial treatment with benzodiazepines: Administer IV lorazepam (or IM midazolam if there is difficulty obtaining IV access). IV access will still need to be established after IM treatment.

• Follow initial treatment with a nonbenzodiazepine AED infusion to prevent recurrence. Most commonly used AEDs include fosphenytoin (preferred), phenytoin, valproate, and levetiracetam.

• Treat refractory status epilepticus with one of the following: midazolam, propofol, or pentobarbital. All patients with refractory status epilepticus should have continuous EEG monitoring.

• Preference for medications varies by institution because of a lack of clear guidelines.

• Most patients with status epilepticus should be managed in an ICU setting.

Treatment Algorithm for Status Epilepticus

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