Clinical Presentation of Spinal Cord Compression
Spinal cord compression presents with a characteristic triad: back pain (90% of patients), motor weakness (67%), and autonomic dysfunction (48%), with the critical understanding that ambulatory status at presentation is the single strongest predictor of post-treatment outcomes and survival. 1, 2
Cardinal Symptoms
Pain Manifestations
- Back pain is present in 90% of patients at presentation, representing the earliest and most common symptom 1, 2
- Radicular pain extends from the spine along nerve root distributions, distinguishing cord compression from simple mechanical back pain 2
- Local pain at the site of compression is common, though back pain alone is not predictive of malignant spinal cord compression 1, 2
Motor Deficits
- Motor weakness and gait deterioration occur in approximately 67% of patients before diagnosis 2
- Up to 50% of patients are unable to walk at presentation, which carries devastating prognostic implications 1
- Progressive weakness typically ascends from distal to proximal muscle groups 3
Sensory Changes
- Numbness, paresthesias, and sensory level deficits are common presenting symptoms 2
- Sensory changes may include loss of pain and temperature sensation below the level of compression 3
- A distinct sensory level on examination helps localize the site of compression 4
Autonomic Dysfunction
- Bladder retention, bowel dysfunction, and sphincter disturbances occur in 48% of patients 2
- Autonomic symptoms represent more advanced compression and predict worse outcomes 1
- Urinary retention is often a late finding indicating severe compression 5
Anatomic Classification and Pathophysiology
Spinal cord compression can be classified as intramedullary, leptomeningeal, or extradural, with extradural compression being most common in malignancy 1, 5
Mechanisms of Extradural Compression
- Continued growth of bone metastases into the epidural space 1
- Blockage of neural foramina by paraspinal tumor mass 1
- Vertebral bone destruction causing collapse and displacement of bony fragments into the epidural space 1
- Vascular obstruction of the epidural venous plexus leading to spinal cord edema and ischemia 1
High-Risk Populations
Lung cancer, prostate cancer, and breast cancer account for 65% of malignant spinal cord compression episodes 2
- Other high-risk malignancies include myeloma and renal cell carcinoma 2
- Asymptomatic patients with extensive bone metastases (>20 lesions) have a 32% risk of spinal cord compression before hormone therapy and 44% after 24 months of treatment 2
- Approximately 2.5% of all cancer patients who die from their disease experience at least one episode of spinal cord compression 1
Critical Prognostic Indicators
Ambulatory Status at Presentation
- Ambulatory patients have a 96-100% chance of remaining ambulatory after treatment 2
- Paraparetic patients have only an 18-30% chance of regaining walking ability 2
- Paraplegic patients have only a 2-6% chance of regaining ambulation 2
- Patients with paralysis at presentation or after treatment have much shorter life expectancy than ambulatory patients 1
Tempo of Neurologic Decline
- Patients with slower motor deficit development (>14 days) have significantly better functional outcomes than those with rapid progression (<14 days) 2
- The speed of symptom progression helps predict treatment response and guides urgency of intervention 2
Common Pitfalls to Avoid
- Waiting for complete urinary retention before referral—this is a late sign indicating severe, potentially irreversible compression 5
- Delaying MRI when spinal cord compression is suspected—any delay minimizes the chance of neurologic recovery 2, 5
- Inadequate assessment of perineal sensation and anal tone during physical examination 5
- Dismissing back pain in cancer patients as musculoskeletal without considering spinal cord compression 6
- Failing to image the entire spine, as multiple levels of compression occur in up to 25% of patients 2
Natural History if Untreated
The natural history of untreated spinal cord compression is relentless and progressive pain, paralysis, sensory loss, and sphincter dysfunction, representing one of the most devastating complications of metastatic cancer 1, 4