Seizures & Epilepsy

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 training. The American Academy of Neurology and American Epilepsy Society issued a guideline for workup and management of a first unprovoked seizure in adults. The following table summarizes common types of seizures.

(Source: Initial Management of Seizure in Adults. N Engl J Med 2021.)

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 electroencephalogram [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

Differential Diagnosis

The following table summarizes the main differential diagnoses of a first generalized tonic-clonic seizure and provides information on the history taking, examination, and initial investigations.

(Source: Initial Management of Seizure in Adults. N Engl J Med 2021.)

Management

The majority of seizures resolve spontaneously within 2 minutes without medication. However, establishing intravenous (IV) access in these patients is critical in case benzodiazepines (IV lorazepam or midazolam) are warranted due to prolonged seizure. If no IV access can be established, intramuscular (IM) midazolam or rectal diazepam can be used as alternatives. Read more on the efficacy of IV versus IM midazolam in the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART).

Treatment is aimed 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. Abnormal findings on electroencephalography (EEG), abnormal neurologic status, and a second seizure all increase the probability of seizure recurrence. These three factors help clinicians stratify low, medium, and high risks and guide decisions about the initiation of antiseizure medication.

(Source: Initial Management of Seizure in Adults. N Engl J Med 2021.)

The following tables summarize first-line antiseizure medications and factors that affect the choice of antiepileptic drug.

(Source: Initial Management of Seizure in Adults. N Engl J Med 2021.)

(Source: Initial Management of Epilepsy. N Engl J Med 2008.)

Status Epilepticus

Status epilepticus is a life-threatening emergency 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: Airway management (often requires intubation), Breathing support with oxygen or mechanical ventilation, Circulation with IV access to administer key medications, 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.

(Source: Status Epilepticus in Adults. Lancet Neurol 2015.)