What is the most appropriate next step in management for a patient with acute hemiparesis and altered mental status, but an unremarkable head computed tomography (CT) scan?

Observation is the Most Appropriate Next Step

This patient should be observed without further acute intervention, as the clinical presentation is most consistent with a postictal (Todd's) paralysis following a seizure, which is already improving spontaneously. 1

Clinical Reasoning

Key Features Supporting Postictal State

• History of epilepsy with congenital brain abnormality makes seizure the most likely precipitant 1
• Tongue abrasion is pathognomonic for tonic-clonic seizure activity 1
• Found down and initially obtunded suggests witnessed or unwitnessed seizure 1
• Transient hemiparesis (Todd's paralysis) can persist for hours to days after seizure, mimicking stroke 1
• Progressive improvement in mental status on re-evaluation confirms the self-limited nature of the event 1
• Unremarkable head CT excludes acute hemorrhage, mass effect, or large territorial infarction 1

Why Not Stroke Treatment?

Alteplase is contraindicated in this scenario for multiple reasons:

• The clinical picture strongly suggests postictal state rather than acute ischemic stroke 1
• Administering thrombolytics to a patient with seizure-related deficits (stroke mimics) carries significant hemorrhagic risk without benefit 1
• The improving neurological status argues against acute vascular occlusion 1

Aspirin is not indicated because:

• This is not an ischemic stroke but rather a seizure-related phenomenon 1
• The patient's deficits are already improving, confirming the transient nature 1

Why Not MRI Brain?

While MRI has superior sensitivity for detecting small infarcts compared to CT (70% of missed strokes presented with altered mental status) 1, urgent MRI is not necessary in this specific case because:

• The clinical trajectory shows spontaneous improvement, which is characteristic of postictal paralysis rather than acute stroke 1
• MRI is most appropriate when occult pathology is suspected after an unrevealing CT in patients with persistent or worsening symptoms 1
• According to ACR guidelines, MRI serves as a second-line test when initial CT is unrevealing and symptoms persist or worsen 1
• The patient's improving mental status and the presence of clear seizure indicators (tongue trauma, epilepsy history) make observation the safer, more appropriate choice 1

Management Algorithm

Immediate actions:

1. Continue observation with serial neurological examinations to document continued improvement 1
2. Monitor for seizure recurrence given history of epilepsy 1
3. Review antiepileptic medication compliance and levels if applicable 1
4. Assess for seizure precipitants including alcohol withdrawal (given alcohol use disorder history), medication noncompliance, or metabolic derangements 1

If deficits persist beyond 24-48 hours or worsen:

• Obtain MRI brain without and with contrast to evaluate for occult stroke, particularly small cortical infarcts that CT may miss 1
• MRI has higher sensitivity for detecting small ischemic infarcts and can identify 70% of strokes that present with altered mental status 1

If new concerning features develop:

• Fever, meningismus, or worsening mental status → consider MRI with contrast to evaluate for CNS infection 1
• Persistent focal deficits → MRI to exclude stroke or structural lesion 1

Critical Pitfalls to Avoid

Do not reflexively treat as stroke when seizure history and tongue trauma are present with improving symptoms—this is a classic stroke mimic 1. The risk of thrombolytic-related hemorrhage in a seizure patient far outweighs any potential benefit 1.

Do not delay observation by pursuing unnecessary imaging when the clinical picture is clear and improving 1. The ACR guidelines specifically note that deferring neuroimaging while observing for symptomatic improvement may be a safe practice in select cases 1.

Do consider alcohol withdrawal as a seizure precipitant in this patient with documented alcohol use disorder—ensure appropriate CIWA protocol and thiamine supplementation 1.