What is the appropriate management and diagnosis for a patient presenting with hyperalgesia in the thighs, numbness in all extremities, and reduced motor strength (4/5) in all extremities?

Urgent Neurological Emergency: Suspect Guillain-Barré Syndrome or Cervical Cord Pathology

This patient requires immediate hospitalization with respiratory monitoring and urgent MRI of the entire spine—the combination of bilateral extremity numbness, diffuse weakness (4/5), and thigh hyperalgesia suggests either Guillain-Barré Syndrome or a cervical cord lesion, both of which can rapidly progress to respiratory failure or permanent paralysis. 1

Immediate Life-Threatening Assessment

Rule Out Guillain-Barré Syndrome First

• Check reflexes immediately: Areflexia or hyporeflexia in all extremities with bilateral weakness strongly suggests GBS 1
• Assess respiratory function now: Measure vital capacity and negative inspiratory force, as approximately 20% of GBS patients develop respiratory failure requiring mechanical ventilation 1
• Ask about preceding infection: Two-thirds of GBS patients report infection within 6 weeks (Campylobacter jejuni, CMV, Hepatitis E, Mycoplasma, EBV, Zika) 1
• Check for dysautonomia: Blood pressure instability, cardiac arrhythmias, or autonomic dysfunction are red flags for GBS 1
• Admit to monitored setting immediately if GBS is suspected, even before confirmatory testing 1

Rule Out Cervical Cord Pathology Simultaneously

• Bilateral hand involvement with lower extremity symptoms indicates cervical cord lesion at C5-C7 level affecting both upper extremities and descending motor tracts 1
• Hyperalgesia in thighs is a critical finding: This burning dysesthesia pattern suggests central cord syndrome, which classically presents with greater upper extremity weakness than lower extremity involvement 1
• Examine for upper motor neuron signs: Hyperreflexia, clonus, and extensor plantar responses suggest cord pathology rather than peripheral neuropathy 1
• The 4/5 weakness pattern in all extremities is atypical for peripheral neuropathy and demands central nervous system evaluation 1

Mandatory Urgent Diagnostic Workup

Imaging (Order Immediately)

• MRI of entire spine without and with contrast is mandatory to exclude cord compression, transverse myelitis, or nerve root enhancement 1
• Do not delay imaging: Central cord syndrome can progress rapidly to complete paralysis 1
• Request neurosurgical consultation immediately if any cord pathology is identified 1

Laboratory Studies (Stat)

• Lumbar puncture with CSF analysis: Cell count, protein, glucose, and oligoclonal bands 1
• Increased CSF protein with normal cell count (albuminocytologic dissociation) supports GBS diagnosis 1
• Check creatinine, eGFR, and urinalysis to exclude uremic neuropathy 1
• Hemoglobin A1c and fasting glucose to assess for diabetic neuropathy, though the acute presentation and motor involvement make this less likely 1

Critical Decision Point

If GBS is Confirmed or Highly Suspected:

• Initiate treatment urgently with IVIG 2 g/kg over 5 days OR plasmapheresis 1
• Do not wait for CSF results if clinical suspicion is high and respiratory function is declining 1
• Continue respiratory monitoring with serial vital capacity measurements 1

If Cervical Cord Lesion is Identified:

• Immediate neurosurgical intervention may be required for cord compression 1
• High-dose IV methylprednisolone may be indicated for transverse myelitis (neurology consultation required) 1

Why Peripheral Neuropathy is Less Likely

• Peripheral neuropathies typically present in "stocking-and-glove" distribution starting distally, not with diffuse 4/5 weakness in all extremities 1
• Motor weakness of 4/5 in all extremities simultaneously is uncommon in peripheral neuropathy unless it is an acute inflammatory demyelinating polyneuropathy (which is GBS) 1, 2
• Hyperalgesia in thighs without distal predominance is atypical for length-dependent peripheral neuropathy 3
• The acute presentation with motor involvement demands exclusion of central pathology first 1

Common Pitfalls to Avoid

• Do not attribute these symptoms to diabetic neuropathy without excluding GBS and cord pathology first: Diabetic neuropathy does not cause acute 4/5 weakness in all extremities 1
• Do not delay imaging to obtain laboratory results: MRI should be performed emergently 1
• Do not discharge this patient: The risk of respiratory failure in GBS and the risk of permanent paralysis from cord compression mandate admission 1
• Do not assume this is a benign peripheral neuropathy: The motor involvement and bilateral distribution are red flags 1