What is the differential diagnosis for a patient presenting with paraplegia and no prior medical history?

Differential Diagnosis of Paraplegia

In a patient presenting with acute paraplegia without prior medical history, immediately assess for spinal cord compression (trauma, epidural abscess, tumor), vascular causes (aortic dissection, spinal cord infarction), inflammatory/infectious causes (transverse myelitis, Guillain-Barré syndrome), and metabolic/toxic etiologies, prioritizing time-sensitive emergent conditions that require immediate intervention. 1, 2

Critical Initial Assessment

Timing and Pattern of Onset

• Acute onset over hours to days suggests Guillain-Barré syndrome (GBS), spinal cord infarction, or aortic dissection 1, 3
• Symptom progression beyond 72 hours may indicate tumor, epidural abscess, or inflammatory causes 1, 4
• Ascending symmetric paralysis is typical of GBS, while sudden bilateral lower extremity paralysis with back pain suggests vascular catastrophe 1, 3

Associated Symptoms Requiring Immediate Action

• Chest or back pain with paraplegia mandates urgent evaluation for aortic dissection, which can present with transient or permanent paraplegia as the initial manifestation 3
• Fever, urinary retention, or bowel dysfunction suggests spinal cord compression from epidural abscess requiring emergency decompression 1, 2
• Dysphagia, dysphonia, diplopia, or breathing difficulties indicate involvement beyond isolated spinal pathology and require immediate neurological consultation 2

Mandatory Diagnostic Workup

Immediate Imaging

• Contrast-enhanced MRI of the entire spine is essential to rule out structural lesions, epidural abscess, tumor, or demyelinating disease 2
• CT angiography of the chest and abdomen if aortic dissection is suspected based on pain pattern or cardiovascular risk factors 3
• Do not delay imaging for laboratory results when spinal cord compression is suspected 1

Essential Laboratory Testing

• Cerebrospinal fluid (CSF) analysis is essential to rule out alternative causes and support the diagnosis of GBS, with key findings including albumino-cytological dissociation 1
• Complete blood count, glucose, electrolytes, kidney and liver function to exclude metabolic or electrolyte causes of weakness 1
• Lyme serology if geographically appropriate, as Lyme disease can cause neurological complications 2

Electrodiagnostic Testing

• Nerve conduction studies and EMG are essential to distinguish between neuropathic, myopathic, and neuromuscular junction disorders, with GBS characterized by prolonged or absent F-waves and conduction block 1, 2
• Do not wait for electrodiagnostic confirmation before initiating treatment in suspected GBS, as treatment delay worsens outcomes 1

Key Differential Diagnoses

Spinal Cord Compression (Surgical Emergency)

• Epidural abscess: fever, back pain, progressive weakness, urinary retention 1, 2
• Tumor (primary or metastatic): gradual progression beyond 72 hours, history of cancer 1, 4
• Traumatic injury: even minor trauma in patients with cervical stenosis can cause acute paraplegia 5, 6
• Cervical disk herniation: neck extension can precipitate acute paraplegia in patients with pre-existing stenosis 5

Vascular Causes (Time-Sensitive)

• Aortic dissection: acute chest/back pain with sudden bilateral lower extremity paralysis, may be transient initially 3
• Spinal cord infarction: sudden onset, often in watershed territories (mid-thoracic or lumbar cord), associated with vascular procedures or hypotension 6
• Arterial embolism or thrombosis: particularly after vascular surgery, angiography, or aortic cross-clamping 6

Inflammatory/Infectious Causes

• Guillain-Barré syndrome: ascending symmetric paralysis over hours to days, areflexia, CSF albumino-cytological dissociation 1
• Transverse myelitis: acute or subacute onset, sensory level, bowel/bladder dysfunction 1, 2
• Lyme disease: in endemic areas, can cause neurological complications 2

Iatrogenic Causes

• Procedures near the spinal cord: laminectomy, vertebrotomy, epidural anesthesia carry risk of mechanical damage 6
• Procedures distant from spinal cord: vascular surgery, angiography, radiotherapy can cause ischemic damage 6
• Positioning during procedures: cervical spine extension during MRI or surgery can precipitate acute paraplegia in patients with stenosis 5

Critical Pitfalls to Avoid

• Do not diagnose isolated peripheral nerve disorder if other neurological deficits are present, as this requires consideration of central or systemic pathology 1, 2
• Do not delay treatment waiting for confirmatory tests in suspected GBS or spinal cord compression, as outcomes worsen with delay 1
• Do not miss aortic dissection by focusing solely on neurological examination; always assess for chest/back pain and cardiovascular risk factors 3
• Consider iatrogenic causes in patients with recent procedures, including seemingly benign interventions like MRI positioning 5, 6