What is the likely diagnosis and recommended treatment for a 53-year-old woman with acute bilateral anterior leg dysesthesia resembling cold water sensation that started one hour ago during a walk, with no recent injury and a COVID-19 infection two weeks ago?

Acute Neurological Emergency Requiring Immediate Vascular and Neurological Evaluation

This patient requires emergent evaluation for acute spinal cord ischemia or acute aortoiliac occlusion (Leriche syndrome), with immediate vascular surgery and neurology consultation. The acute onset of bilateral anterior leg dysesthesia (cold water sensation) during activity in a 53-year-old woman is a red flag for vascular compromise affecting the spinal cord or lower extremities, particularly given the recent COVID-19 infection which increases thrombotic risk.

Immediate Assessment Required

Check bilateral lower extremity pulses immediately (femoral, popliteal, dorsalis pedis, posterior tibial). Absent or diminished pulses indicate acute arterial occlusion requiring emergent intervention 1.

Perform focused neurological examination:

• Motor strength in hip flexors, knee extensors/flexors, ankle dorsiflexion/plantarflexion
• Sensory level to pinprick and light touch
• Deep tendon reflexes (patellar, Achilles)
• Rectal tone and perianal sensation if any motor weakness present
• Temperature of lower extremities (cold suggests vascular compromise)

Most Likely Diagnoses (in order of urgency)

1. Acute Spinal Cord Ischemia (Anterior Spinal Artery Syndrome)

The bilateral anterior leg dysesthesia with acute onset during exertion suggests possible spinal cord ischemia. The anterior spinal artery supplies the anterior two-thirds of the spinal cord, and occlusion causes motor weakness and spinothalamic sensory loss (pain/temperature) while preserving posterior column function (vibration/proprioception).

COVID-19 connection: Recent COVID-19 infection significantly increases thrombotic risk through endothelial dysfunction, hypercoagulability, and inflammatory state 2.

2. Acute Leriche Syndrome (Aortoiliac Occlusion)

Acute thrombotic occlusion of the aortic bifurcation can present with bilateral leg symptoms and even paraplegia if severe enough to compromise spinal cord perfusion 1. The "cold water" sensation may represent acute ischemic dysesthesia.

3. Guillain-Barré Syndrome (GBS)

GBS can present with atypical sensory symptoms including dysesthesias and can be triggered by viral infections including COVID-19 3. However, the hyperacute onset (one hour) and specific "cold water" description make this less likely than vascular etiologies.

4. Post-Acute Sequelae of COVID-19 (PASC) with Neurological Manifestations

While PASC can cause diverse neurological symptoms including peripheral neuropathy 2, the acute onset during activity makes this diagnosis one of exclusion after ruling out emergent conditions.

Emergent Diagnostic Workup

Obtain immediately (within 30 minutes):

1. CT angiography of aorta and lower extremities - to evaluate for aortoiliac occlusion or dissection
2. MRI spine with and without contrast (if CTA negative and neurological deficits present) - to evaluate for spinal cord ischemia, transverse myelitis, or compressive lesions
3. ECG and cardiac biomarkers - COVID-19 increases risk of cardiac complications that could cause embolic phenomena
4. Complete blood count, comprehensive metabolic panel, coagulation studies (PT/INR, PTT, D-dimer)
5. Inflammatory markers (CRP, ESR) - elevated in GBS and post-COVID inflammatory states

If any motor weakness, sensory level, or absent pulses are present, activate vascular surgery and neurology consultations immediately before imaging is complete.

Management Algorithm

If Vascular Occlusion Confirmed:

• Immediate systemic anticoagulation with IV heparin bolus (80 units/kg) followed by infusion (18 units/kg/hr) unless contraindicated 1
• Emergent vascular surgery consultation for catheter-directed thrombolysis, thrombectomy, or bypass
• Time is critical - neurological outcomes depend on rapid revascularization

If Spinal Cord Pathology Confirmed:

• High-dose IV methylprednisolone (1000 mg daily for 3-5 days) if transverse myelitis suspected
• Neurosurgical consultation if compressive lesion identified
• Maintain mean arterial pressure >85 mmHg to optimize spinal cord perfusion

If GBS Suspected (after excluding vascular causes):

• Lumbar puncture for cytoalbuminologic dissociation (elevated protein >60 mg/dL with normal WBC) 3
• Nerve conduction studies and EMG (can be delayed 1-2 weeks if patient stable)
• IVIG 2 g/kg divided over 2-5 days or plasmapheresis if diagnosis confirmed
• Monitor respiratory function closely (vital capacity, negative inspiratory force) as respiratory failure is the major cause of mortality

If All Emergent Workup Negative:

Consider PASC-related neurological manifestations, but this remains a diagnosis of exclusion. Multidisciplinary evaluation including neurology, rheumatology, and infectious disease may be warranted 2.

Critical Pitfalls to Avoid

1. Do not dismiss acute bilateral symptoms as anxiety or functional - the bilateral nature and acute onset during activity suggest organic pathology
2. Do not delay imaging for "observation" - both spinal cord ischemia and acute arterial occlusion are time-sensitive emergencies
3. Do not assume post-COVID symptoms are benign - COVID-19 increases risk of thrombotic complications for weeks after infection 2
4. Do not miss absent pulses - always palpate bilateral lower extremity pulses in patients with acute leg symptoms
5. Do not overlook atypical presentations of GBS - sensory symptoms can precede motor findings and may be described as "sharp zings" or unusual sensations 3

Disposition

Admit to hospital with continuous monitoring regardless of initial workup results given the acute nature and potential for rapid deterioration. If vascular or spinal cord pathology confirmed, ICU-level care is appropriate.