What are the next steps for a female patient presenting with transient leg weakness that has since resolved?

Transient Leg Weakness: Emergency Evaluation and Management

This patient requires immediate emergency department evaluation to rule out acute stroke or transient ischemic attack (TIA), as transient unilateral leg weakness is a very high-risk symptom for imminent stroke with up to 36% risk within 7 days if multiple risk factors are present. 1

Immediate Triage Classification

This presentation falls into the VERY HIGH RISK category for stroke/TIA based on Canadian Stroke Best Practice guidelines 1:

• Transient unilateral leg weakness within 48 hours = highest stroke risk 1
• Patient should be sent immediately to an emergency department with brain imaging capacity and acute stroke treatment capability 1
• Do not delay—this is a potential stroke emergency even though symptoms resolved 1

The American Heart Association confirms that acute onset leg weakness with subsequent resolution requires immediate stroke protocol activation with urgent neuroimaging 2.

Critical Time-Sensitive Actions

Within 24 Hours (Urgent)

Brain imaging (CT or MRI) and vascular imaging (CTA or MRA from aortic arch to vertex) must be completed within 24 hours 1. The rationale is that even though symptoms resolved, this represents a warning event with extremely high recurrence risk 1.

Obtain ECG without delay to assess for atrial fibrillation or other cardiac sources of embolism 1.

Calculate NIHSS score to quantify any residual neurological deficit and establish baseline for monitoring 2.

Immediate Bedside Assessment

Check bilateral lower extremity pulses immediately 3. While stroke/TIA is most likely given the transient nature, acute limb ischemia can present with leg weakness and numbness that may fluctuate 3:

• Absent or significantly diminished pulses = vascular emergency requiring immediate vascular surgery consultation within 6 hours 3
• Acute limb ischemia presents with the "6 P's": pain, pulselessness, pallor, paresthesias, paralysis, and poikilothermia (coolness) 1, 3
• Use handheld Doppler if pulse palpation uncertain—loss of Doppler arterial signal indicates threatened limb 3

Differential Diagnosis Priority

1. Transient Ischemic Attack (Most Likely)

Transient unilateral leg weakness is a cardinal TIA symptom with 2.1% stroke risk at 7 days even with rapid treatment, and historically up to 10.3% without immediate intervention 1.

Key features supporting TIA 1:

• Sudden onset with complete resolution
• Unilateral distribution
• Duration typically minutes to hours
• May have associated sensory symptoms

2. Acute Limb Ischemia (Must Rule Out)

Weakness and numbness commonly occur with severe acute limb ischemia, and determining whether dysfunction is worsening or improving is crucial 3.

Features suggesting vascular etiology 1, 3:

• Pain extending above the ankle
• Coolness of affected limb
• Pallor or mottling
• Absent pulses

3. Lumbar Spinal Stenosis with Neurogenic Claudication (Less Likely Given Acute Presentation)

Transient leg weakness provoked by walking that resolves with rest suggests neurogenic claudication 4, but this typically has a more gradual onset pattern and would be unusual for a walk-in clinic presentation stating "legs stopped working."

Essential Diagnostic Workup

Immediate Laboratory Studies

Obtain blood glucose, complete blood count, electrolytes, renal function, PT/INR, aPTT, and cardiac markers 2. These are required before any thrombolytic consideration if the patient has recurrent symptoms 2.

Vascular Assessment if Pulses Abnormal

If pulses are diminished or absent, obtain ankle-brachial index (ABI) immediately 1, 3:

• ABI <0.90 is diagnostic for peripheral artery disease 1
• Absolute systolic pressure ≤50 mmHg at ankle or ≤30 mmHg at toe suggests amputation risk without revascularization 3

Management Algorithm

If Stroke/TIA Confirmed (Most Likely Scenario)

Admit to stroke unit or intensive care setting with continuous neurological monitoring 2.

Initiate comprehensive secondary stroke prevention 1:

• Antiplatelet therapy (aspirin or clopidogrel)
• High-intensity statin therapy
• Blood pressure management
• Atrial fibrillation screening with prolonged cardiac monitoring

Neurology consultation is mandatory for ongoing management and treatment decisions 2.

If Acute Limb Ischemia Identified

Start systemic anticoagulation with unfractionated heparin immediately unless contraindicated 3.

Categorize limb status 3:

• Category I (viable): Urgent vascular surgery consultation
• Category IIa (marginally threatened): Emergency vascular surgery consultation
• Category IIb (immediately threatened): Immediate revascularization required
• Category III (irreversible): Primary amputation indicated

Critical Pitfalls to Avoid

Do not reassure and discharge based on symptom resolution—transient symptoms are a warning of imminent stroke 1.

Do not delay imaging to obtain extensive laboratory workup—time to diagnosis is critical 2.

Do not assume musculoskeletal etiology without vascular and neurological evaluation—bilateral leg weakness in isolation is rarely musculoskeletal 1, 3.

Do not overlook pulse examination—absent pulses with unilateral symptoms indicate vascular emergency 3.

Follow-Up Requirements

If discharged from ED after negative workup, schedule follow-up within 1-2 weeks to monitor for recurrent symptoms and ensure secondary prevention measures are optimized 2.

Patient requires verbal and written instructions regarding self-surveillance for symptom recurrence 1, specifically:

• Return immediately for any recurrent weakness, numbness, or speech changes
• Recognize warning signs of stroke (FAST: Face drooping, Arm weakness, Speech difficulty, Time to call 911)