Pocket Oncology (Pocket Notebook Series), 1st Ed.

SPINAL CORD COMPRESSION

Parisa Momtaz and Jeffrey S. Groeger

Definition/Risk Factors

• Mets on the vertebral body extend, invades the epidural space, compressing the thecal sac → causing ESCC → lead to infarction of spinal cord & irreversible loss of neurologic function

• Conus medullaris syndrome: Symmetric saddle anesthesia, bladder & bowel dysfunction), absent bulbocavernosus & anal reflexes

• Cauda equina syndrome: Sev. back pain, leg weakness, &/or sensory loss ± ↓ reflexes in lower extremities, relative sparing of bowel & bladder function

• Met tumor from any 1° site can cause ESCC; most common CA include: Lung, breast, prostate, RCC, NHL, MM

• Neuro-oncologic emergency

Anatomy

• Tip of the spinal cord lies at L1 vertebral level

• Below L1, the lumbosacral nerves form the cauda equina

• Conus medullaris: Terminal end of the spinal cord at L1/L2

• Sites of ESCC involvement: Thoracic (70%), lumbar (20%), cervical (10%)

Figure 9-2

Clinical Manifestations

• S/s depending on location & degree of thecal sac compression

• Back pain (96%)

• LE weakness

• Autonomic dysfunction (urinary retention/incontinence, decreased anal sphincter tone → bowel incontinence)

• Sensory loss (medial thigh)

• Ataxia

• Note: Pain on movement only suggests spinal instability

• Abrupt worsening of pain may indicate a pathologic compression fracture

• If acute: Flaccid paraparesis & absent reflexes

• If subacute to chronic: Spastic paraparesis & hyperactive reflexes

• Posterior column dysfunction in legs (loss of vibratory sense or proprioception)

• Bilateral Babinski responses

Diagnostic Evaluation

• Do not wait for neurologic signs to develop!

• Most important prognostic factor for regaining neurologic function is pre-tx neurologic status (Ann Neurol 1978;3:40)

• Obtain a STAT whole spine MRI as multiple spinal epidural mets may be found (AJR 1987;149:1241)

• If cannot do MRI, obtain a CT myelogram

• Other diagnostic radiographic modalities: CT whole spine, plain spine films, bone scans

• If sx of HA, meningismus, obtain CSF for evaluation; however, spinal cord compression evaluation takes precedence over investigation of leptomeningeal involvement

• Consult radiation oncology & neurosurgical services

Treatment

• Initate Rx immediately while awaiting imaging if back pain & neurologic deficits

• Dexamethasone 10 mg IV followed by 4 mg IV or PO q6h(JCO 1988;6:543)

• Reserve dexamethasone doses of 100 mg/d for pts w/sev. neurologic dysfunction followed by rapid taper

• Pain control w/opiate analgesics

• Emergent XRT or surgical decompression if confirmed compression/neurologic deficits

• If pathologic fracture causing compression consult appropriate surgical service: Neurosurgery, orthopedics

• If not a surgical candidate, consult radiation oncology service

• Neurosurgery is superior to XRT in regaining neurofunction for solid tumors (Lancet 2005;366:643)

• Pre-tx status is most important predictor of post-tx status

Figure 9-3

Figure 9-4 Uptodate courtesy of David Schiff, MD.