APPROACH TO THE PATIENT Spinal Cord Compression
Initial symptoms of focal neck or back pain may evolve over days to weeks; followed by combinations of paresthesias, sensory loss, motor weakness, and sphincter disturbance evolving over hours to several days. Partial lesions may selectively involve one or more tracts and may be limited to one side of the cord. In severe or abrupt cases, areflexia reflecting spinal shock may be present, but hyperreflexia supervenes over days to weeks. With thoracic lesions, a sensory level to pain may be present on the trunk, indicating localization to the cord at that dermatomal level.
In pts with spinal cord symptoms, the first priority is to exclude treatable compression by a mass. Compression is more likely to be preceded by warning signs of neck or back pain, bladder disturbances, and sensory symptoms prior to development of weakness; noncompressive etiologies such as infarction and hemorrhage are more likely to produce myelopathy without antecedent symptoms.
MRI with gadolinium, centered on the clinically suspected level, is the initial diagnostic procedure. CT myelography can be helpful in pts who have contraindications to MRI. It is important to image the entire spine to search for additional clinically silent lesions. Infectious etiologies, unlike tumor, often cross the disc space to involve adjacent vertebral bodies.
NEOPLASTIC SPINAL CORD COMPRESSION
Occurs in 5–10% of pts with cancer; epidural tumor may be the initial manifestation of malignancy. Most neoplasms are epidural in origin and result from metastases to the adjacent spinal bones. Almost any malignant tumor can metastasize to the spinal column, with lung, breast, prostate, kidney, lymphoma, and plasma cell dyscrasia being particularly frequent. The thoracic cord is most commonly involved; exceptions include prostate and ovarian tumors, which preferentially involve the lumbar and sacral segments from spread through veins in the anterior epidural space. Urgent MRI is indicated when the diagnosis is suspected; up to 40% of pts with neoplastic cord compression at one level are found to have asymptomatic epidural disease elsewhere, thus, imaging of the entire length of the spine is important to define the extent of disease. Plain radiographs will miss 15–20% of metastatic vertebral lesions.
TREATMENT Neoplastic Spinal Cord Compression
Glucocorticoids to reduce edema (typically dexamethasone, 10 mg intravenously) can be administered before the imaging study if the clinical suspicion is high, and continued at a lower dose (4 mg every 6 h orally) until radiotherapy (generally 30−40 Gy administered in 8−10 fractions) and/or surgical decompression is completed.
Early surgery, either decompression by laminectomy or vertebral body resection, followed by radiotherapy is more effective than radiotherapy alone for pts with a single area of spinal cord compression by extradural tumor. Surgery also indicated when cord compression worsens despite radiotherapy, when maximum dose of radiotherapy has been delivered previously to the site, or when a vertebral fracture or spinal instability contributes ...