What is the diagnosis and disposition for a 19-year-old female with transient aphasia and blurred vision, stable vitals, negative neurological exam, and normal lab results, including computed tomography (CT) head, complete blood count (CBC), and comprehensive metabolic panel (CMP)?

Differential Diagnosis and Disposition for 19-Year-Old Female with Transient Aphasia and Blurred Vision

This patient most likely experienced a transient ischemic attack (TIA) or migraine with aura, and should be admitted or placed in an observation unit for urgent vascular imaging and cardiac evaluation within 24 hours given the high early stroke risk. 1

Primary Differential Diagnosis

Transient Ischemic Attack (TIA)

• TIA is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction 2
• The combination of aphasia (focal cortical symptom) and visual disturbance lasting one hour fits the classic TIA presentation 3
• Young patients can have TIA from uncommon causes including cardiac embolism, hypercoagulable states, vasculitis, or arterial dissection 3
• The 2-day stroke risk after TIA ranges from 3.5% to 10%, rising to 17% by 90 days 4

Migraine with Aura

• Migraine with aura commonly presents with transient visual and language disturbances in young women
• Key distinguishing feature: gradual symptom onset over minutes (typical of migraine) versus sudden onset (typical of TIA) 5
• Presence of headache following the neurological symptoms would support migraine, though headache can also occur with TIA 3

Less Likely Considerations

• Seizure with postictal aphasia - less likely given the negative neurological exam and absence of witnessed seizure activity 3
• Conversion disorder/psychogenic - possible in young patients but should be a diagnosis of exclusion 3
• Metabolic derangement - ruled out by normal CMP and glucose 3

Critical Missing Workup

Urgent Vascular Imaging (Within 24-48 Hours)

• CTA of the head and neck is recommended to evaluate for intracranial atherosclerosis, extracranial vascular disease, and arterial dissection 1
• Noninvasive imaging of cervical carotid arteries should be performed within 48 hours for patients who may be candidates for intervention 1
• MRI with diffusion-weighted imaging is preferred over CT as it can detect acute infarction in up to 30-50% of patients with clinical TIA 2

Cardiac Evaluation

• EKG should be performed immediately as a necessary component of initial assessment to identify cardioembolic sources 1
• Prolonged cardiac monitoring (24-48 hours) is reasonable to detect paroxysmal atrial fibrillation 2
• Echocardiography should be considered to evaluate for structural cardiac abnormalities, patent foramen ovale, or valvular disease 2

Additional Testing

• Hypercoagulability workup is indicated in young patients without traditional vascular risk factors, including antiphospholipid antibodies, protein C/S, factor V Leiden 3
• ESR/CRP to evaluate for vasculitis 3
• Toxicology screen for sympathomimetic drugs (cocaine, amphetamines) that can cause stroke in young patients

Disposition Recommendation

Admit or Observation Unit

This patient should be hospitalized or placed in an observation unit for the following reasons: 1, 2

• First TIA within 24 hours requires hospitalization to facilitate rapid diagnostic workup and institution of secondary prevention 6
• Symptoms lasted one hour (duration >1 hour is an indication for admission) 6
• Young age with no identified etiology requires comprehensive evaluation that cannot be completed rapidly as outpatient 2
• Delaying imaging beyond 48 hours increases recurrent stroke risk to 8.8% at 7 days 1

Outpatient Management Would Be Inappropriate Because:

• Vascular imaging has not been completed 1
• Cardiac evaluation beyond basic EKG has not been performed 1
• Etiology remains completely unknown in a young patient 2
• Rapid access to imaging and specialist evaluation (within 12 hours) cannot be guaranteed in most outpatient settings 1

Common Pitfalls to Avoid

• Do not discharge based solely on negative CT head - CT is insensitive for acute ischemia and does not exclude TIA 1
• Do not assume "too young for stroke" - young patients can have TIA from dissection, hypercoagulable states, or cardiac sources 3
• Do not rely on normal neurological exam to exclude TIA - by definition, TIA symptoms have resolved by the time of evaluation 2
• Do not delay vascular imaging - carotid territory TIA with significant stenosis has a 90-day ipsilateral stroke risk of 20.1% 1
• Gradual symptom onset, prior unexplained attacks, and nonspecific symptoms increase likelihood of non-ischemic etiology (adjusted OR 6.7,10.6, and 4.2 respectively), but these features are not documented in this case 5

Immediate Management While Admitted

• Aspirin 325mg loading dose (if not contraindicated) 2
• Blood pressure monitoring but avoid aggressive lowering acutely 2
• NPO until swallow evaluation if any concern for recurrent symptoms 2
• Neurology consultation 2
• Expedited MRI brain with DWI and MRA head/neck, or CTA head/neck if MRI unavailable 1, 2