Spinal cord compression (non-traumatic)

Background

• Non-traumatic spinal cord compression is an oncologic and neurologic emergency
• Most commonly from metastatic cancer (breast, lung, prostate, renal, myeloma, lymphoma)
• Site: thoracic spine (60-70%) > lumbar > cervical
• Neurologic deficits may be irreversible if treatment is delayed — time is spine
• The cauda equina begins at the L2 level; compression below this level produces a lower motor neuron pattern

Epidural compression syndromes

Sensory dermatome by spinal level.

• Syndromes
  • Spinal cord injury
  • Spinal cord compression (non-traumatic)
  • Cauda equina syndrome
  • Conus medullaris syndrome
• Causes
  • Spinal cord injury
  • Epidural abscess (spinal)
  • Epidural hematoma (spinal)
  • Syringomyelia

Clinical Features

• Back pain is the earliest and most common symptom (>90%) — often precedes neurologic deficits by weeks
• Progressive weakness (typically bilateral)
• Sensory loss below the level of compression (sensory level)
• Bowel/bladder dysfunction (late finding — urinary retention, incontinence)
• Gait difficulty

Epidural compression syndromes table

Syndrome	Spinal cord compression	Conus medullaris syndrome	Cauda equina syndrome
Location of lesion		Lesions at vertebral level L2
Spontaneous pain		Unusual and not severe; bilateral and symmetrical in perineum or thighs	Often very prominent and severe, asymmetrical, radicular
Motor findings	Deficits usually affect both legs but are often asymmetric	Not severe, symmetrical; rarely twitches	May be severe, asymmetrical, fibrillary twitches of paralyzed muscles are common
Sensory findings	Weakness in lower extremities, paresthesias/sensory deficits, gait difficulty	Saddle distribution, bilateral, symmetrical, disassociated sensory loss (impaired pain and temperature with sparing of tactile)	Saddle distribution (75% pts), may be asymmetrical, no dissociation of sensory loss
Reflex changes		Achilles reflex may be absent	Patellar and Achilles reflexes may be absent
Sphincter disturbance	Bladder and rectal sphincter paralysis usually reflect the involvement of S3-S5 nerve roots	Early and marked (both urinary and fecal)	Late and less severe (60-80% pts)
Male sexual function		Impaired early	Impairment less severe
Onset		Sudden and bilateral	Gradual and unilateral
Other			Urinary retention with or without overflow incontinence (Sn 90%, Sp 95%)

Red Flags

• Known cancer + new back pain (cord compression until proven otherwise)
• Bilateral leg weakness
• Sensory level on exam
• Urinary retention or incontinence
• Saddle anesthesia

Differential Diagnosis

Spinal Cord Syndromes

• Complete spinal cord transection syndrome
• Anterior cord syndrome
• Central cord syndrome
• Brown-Séquard syndrome
• Epidural compression syndromes
  • Spinal cord compression (non-traumatic)
  • Cauda equina syndrome
  • Conus medullaris syndrome
  • Epidural abscess (spinal)
  • Epidural hematoma (spinal)

Lower Back Pain

• Spine related
  • Acute ligamentous injury
  • Acute muscle strain
  • Disk herniation (Sciatica)
  • Degenerative joint disease
  • Spondylolithesis
  • Epidural compression syndromes
    • Spinal cord compression (non-traumatic)
    • Cauda equina syndrome
    • Conus medullaris syndrome
    • Epidural abscess (spinal)
    • Epidural hematoma (spinal)
  • Thoracic and lumbar fractures and dislocations
  • Cancer metastasis
  • Spinal stenosis
  • Transverse myelitis
  • Vertebral osteomyelitis
  • Ankylosing spondylitis
  • Spondylolisthesis
  • Discitis
  • Spinal Infarct
• Renal disease
  • Kidney stone
  • Pyelonephritis
  • Nephrolithiasis
• Intra-abdominal
  • Abdominal aortic aneurysm
  • Ulcer perforation
  • Retrocecal appendicitis
  • Large bowel obstruction
  • Pancreatitis
• Pelvic disease
  • PID
• Other
  • Retroperitoneal hemorrhage/mass
  • Meningitis

Causes

• Metastatic epidural disease (most common)
• Epidural abscess (fever, IVDU, recent procedure)
• Epidural hematoma (anticoagulation, post-procedure)
• Primary spinal tumor
• Disc herniation (massive central herniation)
• Vertebral fracture with retropulsion

Evaluation

• MRI of entire spine is the study of choice — order emergently
  • Image entire spine (may have multiple levels of compression)
  • If MRI unavailable: CT myelography
• Bladder scan for post-void residual (>200 mL suggests neurogenic bladder)
• Emergent MRI
  • If considering compression due to neoplasm obtain scan of entire spine
• Consider Bladder scan/ultrasound for bladder volume (post-void residual)

Labs

• CBC, BMP, coagulation studies
• ESR, CRP (elevated in abscess, tumor)
• Blood cultures if abscess suspected
• PSA, serum protein electrophoresis if cancer workup needed

Management

• Emergent consultation: neurosurgery and/or radiation oncology
• Dexamethasone: 10 mg IV bolus then 4 mg IV q6h (for malignant compression)
  • Controversial for non-malignant causes — consider risks
  • Do NOT give steroids if epidural abscess suspected (will worsen infection)
• Definitive treatment: emergent radiation, surgical decompression, and/or chemotherapy based on tumor type
• Epidural abscess: emergent surgical drainage + IV antibiotics
• Epidural hematoma: reverse anticoagulation, emergent surgical evacuation
• Foley catheter for urinary retention

General Epidural Compression Syndrome Management

• Dexamethasone: at least 16 mg IV as soon as possible after assessment
  • Note: dexamethasone can be used to reduce compressive edema from epidural metastases, but is more likely to worsen an infection from spinal epidural abscess.
• Consult spine service
• Consider foley for bladder decompression

Disposition

• Admit all patients with confirmed or suspected cord compression
• ICU if hemodynamically unstable or rapidly progressing deficits
• Ambulatory status at time of diagnosis is the strongest predictor of outcome — patients who are still ambulatory have the best prognosis

See Also

• Epidural compression syndromes
• Cauda equina syndrome
• Spinal Cord Trauma
• Epidural abscess (spinal)
• Spinal cord syndromes