What are the differential diagnoses for spinal cord compression?

Differential Diagnoses for Spinal Cord Compression

Spinal cord compression must be categorized into compressive (extrinsic) versus non-compressive (intrinsic) etiologies, with the primary distinction being whether surgical decompression is needed—this fundamentally determines morbidity and mortality outcomes 1.

Algorithmic Approach to Differential Diagnosis

Step 1: Determine if Compression is Extrinsic (Compressive) or Intrinsic (Non-compressive)

The anatomic compartment localizes the pathology and guides management:

A. Extrinsic Compression (Requires evaluation for surgical decompression)

Epidural Space Lesions:

• Degenerative disease (spondylotic myelopathy) - Most common cause in acute setting, particularly cervical spine. Look for disc herniations, osteophytes, ligamentum flavum hypertrophy, and spinal canal stenosis 1
• Metastatic/primary tumors - Extradural masses from lung, breast, prostate cancer, myeloma, or lymphoma. Most common malignant cause 2, 3
• Epidural abscess - Consider in patients with fever, elevated inflammatory markers, or immunosuppression 1
• Epidural hematoma - Occurs with anticoagulation, trauma, or coagulopathy 1
• Postoperative complications - Seromas, pseudomeningoceles, hematomas in surgical patients 1

Intradural Extramedullary Space:

• Primary tumors (meningiomas, nerve sheath tumors) - Progressive course 1
• Metastatic disease - Less common than epidural metastases 1

Osseous Causes:

• Pathologic fractures - From osteoporosis or metastatic disease with vertebral body collapse and retropulsion, even without significant trauma 1
• Spinal instability/malalignment - Particularly with congenitally short pedicles 1

B. Intrinsic (Intramedullary) Non-Compressive Causes

Vascular:

• Spinal cord ischemia - From atheromatous disease, aortic surgery complications, systemic hypotension, aortic dissection, or sickle cell disease. Presents with acute paraparesis/quadriparesis 1
• Spinal arteriovenous malformations (AVMs) or dural fistulas - Chronic progressive course with venous hypertension 1
• Hematomyelia - Rare, from intramedullary AVM or spinal artery aneurysm rupture 1

Inflammatory/Demyelinating:

• Multiple sclerosis (MS) - 80-90% have spinal cord involvement, typically cervical, with lesions <2 vertebral segments 1
• Neuromyelitis optica (NMO) - Longitudinally extensive lesions (≥3 vertebral segments) 1
• Acute disseminated encephalomyelitis (ADEM) 1
• Transverse myelitis - Autoimmune or post-infectious 4

Infectious:

• Viral myelitis - Human T-cell lymphotropic virus, HIV vacuolar myelopathy 1
• Bacterial - Tuberculosis, tertiary syphilis 1
• Parasitic - Schistosomiasis 1

Metabolic:

• Subacute combined degeneration - Vitamin B12 (cobalamin) deficiency, copper deficiency, nitrous oxide toxicity 1

Systemic Inflammatory:

• Systemic lupus erythematosus, Sjögren syndrome, mixed connective tissue disorder, Behçet disease, sarcoidosis 1

Neoplastic (Intramedullary):

• Primary spinal cord tumors (astrocytomas, ependymomas) or intramedullary metastases 1

Other:

• Radiation myelopathy - Dose-dependent, localizes to prior radiation port 1
• Paraneoplastic myelopathy 1

Step 2: Timing and Presentation Pattern

Acute Onset (<24-48 hours):

• Prioritize: Epidural abscess, epidural hematoma, acute disc herniation, spinal cord ischemia, pathologic fracture
• Critical pitfall: Delay in diagnosis leads to irreversible neurologic deficit—pretreatment motor function is the strongest prognostic factor 2

Chronic/Progressive (weeks to months):

• Prioritize: Spondylotic myelopathy, tumors (primary or metastatic), demyelinating diseases, metabolic causes, vascular malformations

Step 3: Key Clinical Discriminators

Presence of back pain (95% of malignant compression):

• Suggests compressive etiology, particularly malignancy or infection 5, 3

Sensory level present:

• Suggests extrinsic compression or intrinsic cord pathology
• Absence of sensory disturbance with motor findings should raise suspicion for non-compressive neurological diseases (parkinsonian syndromes, ALS, cerebrovascular disease) 6

Pattern of weakness:

• Bilateral extensive upper extremity paresis without sensory findings → consider non-compressive causes 6
• Acute paraparesis/quadriparesis → spinal cord ischemia 1

Gait abnormality:

• Non-spastic abnormal gait → consider parkinsonian syndromes rather than myelopathy 6

Sphincter dysfunction:

• Common in both compressive and non-compressive causes but suggests more severe cord involvement

Fever/elevated inflammatory markers:

• Epidural abscess or infectious myelitis 1

Cancer history:

• Metastatic epidural compression (lung, breast, prostate, myeloma most common) 2, 5, 3

Recent spinal surgery:

• Postoperative hematoma, seroma, pseudomeningocele, or abscess 1

Critical Management Principle

All patients with suspected spinal cord compression require emergent MRI of the entire spine (not just symptomatic level) to identify compressive versus non-compressive causes and guide surgical versus medical management 2, 1, 4. The distinction between extrinsic compression requiring decompression and intrinsic cord pathology requiring medical therapy is the most critical decision point affecting mortality and permanent disability.