What is the recommended workup and treatment for a patient presenting with seizures?

Workup for Seizures

For new-onset seizures in adults, obtain serum glucose and sodium levels immediately, perform emergent head CT without contrast if high-risk features are present, and arrange outpatient MRI and EEG for low-risk patients who have returned to baseline.

Immediate Laboratory Testing

Essential labs that alter acute management:

• Serum glucose and sodium are the only laboratory tests that consistently require immediate intervention 1
• Pregnancy test if patient is of childbearing age 1
• Additional labs (CBC, comprehensive metabolic panel) should be obtained only when suggested by specific clinical findings such as vomiting, diarrhea, dehydration, or known cancer/renal failure 1

Lumbar puncture indications:

• Fever with meningeal signs or concern for meningitis/encephalitis 1
• Immunocompromised patients (after head CT) 1
• Not indicated for routine uncomplicated first-time seizures 1

Neuroimaging Decision Algorithm

Perform emergent head CT without contrast in the ED if ANY of the following high-risk features are present 1:

• Age >40 years
• History of malignancy or immunocompromised state
• Recent head trauma
• Fever or persistent headache
• Focal neurological deficits that do not quickly resolve
• Partial-onset seizures before generalization
• Patients on anticoagulation
• Persistent altered mental status after seizure
• Patient has not returned to baseline within several hours

For low-risk patients (young, returned to baseline, normal neurologic exam, reliable follow-up), deferred outpatient MRI is acceptable 1. MRI is the preferred imaging modality for non-emergent evaluation as it is more sensitive than CT for detecting epileptogenic lesions 1.

Electroencephalography (EEG)

EEG should be obtained as part of the neurodiagnostic evaluation of a child or adult with an apparent first unprovoked seizure 1. Abnormal EEG findings predict increased risk of seizure recurrence 1.

Emergent EEG is indicated for:

• Persistent altered consciousness after seizure to detect nonconvulsive status epilepticus 2
• Refractory status epilepticus 2
• When patient has not returned to baseline within expected timeframe, as nonconvulsive status epilepticus occurs in >50% of cases 3

Disposition Decisions

Emergency physicians need not admit patients with a first unprovoked seizure who have returned to their clinical baseline in the ED 1.

Consider admission if any of the following are present 1:

• Persistent abnormal neurological examination results
• Abnormal investigation results requiring inpatient management
• Patient has not returned to baseline
• Unreliable follow-up arrangements

Seizure Recurrence Risk

The mean time to first seizure recurrence is 121 minutes (median 90 minutes), with more than 85% of early seizures recurring within 6 hours 1. The overall 24-hour recurrence rate is 19%, decreasing to 9% when alcohol-related events and focal CT lesions are excluded 1.

Higher recurrence risk at 1 year (14-36%) is associated with 1:

• Abnormal neurological examination
• Abnormal EEG
• Remote symptomatic seizures
• Todd's paralysis

Nonalcoholic patients with new-onset seizures have the lowest recurrence rate (9.4%) 1.

Common Pitfalls to Avoid

• Approximately 28-48% of suspected first seizures have alternative diagnoses (syncope, nonepileptic seizures, panic attacks), highlighting the importance of careful history 1
• Failing to identify metabolic abnormalities such as hypoglycemia or hyponatremia that may be causing the seizure 1
• Missing structural lesions by not performing appropriate neuroimaging 1
• Alcohol withdrawal seizures should be a diagnosis of exclusion, especially in first-time seizures—symptomatic causes should always be searched for before labeling as withdrawal seizures 1

Antiepileptic Drug Initiation

Antiepileptic drug treatment reduces 1-2 year recurrence risk but does not affect long-term recurrence rates or remission rates 1. Starting treatment for a single seizure exposes patients to medication adverse effects without proven mortality or morbidity benefit 1. The decision to initiate AED therapy should be made in consultation with neurology and based on individual recurrence risk factors.