Neoplastic disease that involves the spine and results in spinal cord or cauda equina compression may have devastating neurologic and functional consequences.
Metastatic lesions are responsible for about 85% of neoplastic spinal cord compression cases, with the other 15% due to primary neoplastic lesions of the spine. The clinical presentation in compression caused by metastatic lesions tends to be indistinguishable from that caused by primary disease. For the emergency physician, however, the cell origin of the tumor is less of a concern than the consequent syndromes of spinal cord dysfunction. These patients require rapid diagnosis and treatment to prevent permanent complications (see Presentation, Workup, and Treatment).
Neoplastic disease can cause neurologic symptoms by compression of the thecal sac, spinal cord, or cauda equina, as well as compression of the attendant vascular supply, which results in cord edema and ischemia. The neural tracts most vulnerable to mechanical pressure include the corticospinal and spinocerebellar tracts and the posterior spinal columns. Infrequently, tumors may induce cavitation within the spinal cord.
Metastatic spinal cord comression
Metastatic spinal cord compression is due to invading lesion(s) in the epidural space, between the vertebral bones and the dura of the thecal sac, compressing the thecal sac, spinal cord, or cauda equina.
Systemic cancers with a tendency for spinal metastasis include the following:
Breast cancer
Prostate cancer
Renal cancer
Lung cancer
Lymphoma (in both adults and pediatric populations)
Sarcoma (eg, Ewing sarcoma in pediatric populations)
Multiple myeloma
Metastatic spinal cord compression usually follows arterial hematogenous dissemination of malignant cells to the vertebral bodies, with subsequent expansion into the epidural space. Spread into the epidural space may also occur by means of tumor extension through the intervertebral foramina (as is common with lymphoma) or hematogenous spread to the vertebral bodies by way of the Batson venous plexus (particularly with prostate cancer).[1]
Most frequently, metastatic seeding involves the thoracic spine (accounting for about 70% of cases), with the lumbar spine being the next most involved site (20% of cases). The cervical spine is affected in approximately 10% of cases. Multiple spinal levels are affected in about 30% of patients.[1] Gastrointestinal and pelvic malignancies tend to affect the lumbosacral spine. Lung and breast cancers are more likely to affect the thoracic spine.
Metastases to the substance of the cord (intramedullary) are relatively rare. Signs and symptoms in such cases tend to resemble those of epidural compression; however, if motor weakness is present, it is more likely to be unilateral. Principles of treating intramedullary cancer are similar to those for epidural spinal cord compression.
Leptomeningeal metastases spread by means of diffuse or multifocal seeding of the meninges from advanced systemic cancer (eg, lung or breast cancer, melanoma, lymphoma). Leptomeningeal metastasis presents as multifocal neurological deficits referable to the spinal cord.
Primary spinal cord tumors
Primary spinal cord tumors arise from the different elements of the central nervous system (CNS), including neurons, supporting glial cells, and meninges. Anatomically, neoplasms of the spinal cord may be classified according to the compartment of origin, either intramedullary (inside the cord) or extramedullary (outside the cord).
Most primary intramedullary spinal cord tumors are astrocytomas or ependymomas.[2] Intradural extramedullary tumors—including schwannomas, neurofibromas, and meningiomas[2] —that affect the paravertebral area may spread and compress the cord through expansion. Occasionally, an enlarging cancerous lymph node may also compress the cord.
Hemangiomas
Hemangiomas (benign tumors of the blood vessels) are usually discovered incidentally and usually do not produce symptoms. However, symptoms can emerge if pathologic vertebral fractures or epidural extension occurs.
Metastatic lesions that involve the spinal cord affect about 5-10% of patients with cancer.[3] Approximately 15% of all primary CNS lesions arise from the spinal cord, with an estimated incidence rate of 0.5-2.5 cases per 100,000 population.
International
The international incidence rate parallels that of the United States.
Mortality/Morbidity
Most primary spinal cord cancers do not disseminate widely through the CNS or body. Consequent disability relates to the degree of cord impairment and anatomic level of cord injury.
Metastatic tumors that cause epidural cord compression and dysfunction are the most common causes of oncologic CNS injury. Mortality correlates with the prognosis of the primary cancer.
The severity of spinal cord compromise secondary to a tumor spans a wide range. Initially, symptoms may be limited to pain or minor sensory or motor disturbance. As the compression progresses, neurologic abnormalities become more pronounced, advancing to disability. Partial cord compression, such as Brown-Séquard syndrome, may evolve. In the advanced stage of compression, complete transverse sensory and motor paralysis with bowel and bladder incontinence occurs.
The degree of disability at the initiation of therapy serves as the best predictor of ultimate disability in patients with epidural cord compression. Early detection of cord compression and early intervention is the goal.
Sex- and age-related demographics
A slight male predominance exists for primary spinal cord tumors. Symptomatic hemangiomas occur most frequently in teenaged girls and typically involve the thoracic spine.
The incidence of primary spinal cord tumors peaks in people aged 30-50 years. People older than 50 years are more likely to experience back pain secondary to a metastatic tumor. Certain CNS tumors, such as neuroblastoma, occur almost solely in pediatric patients.
Clinical syndromes produced by intramedullary tumors vary depending on the age of the individual. In children, gait disturbances prevail, with pain reported infrequently. Spinal cord neoplasms may manifest as scoliosis or torticollis in younger patients.
Pain is the most common early complaint of adult patients with spinal cord neoplasms, followed by the insidious progression of spinal cord dysfunction.
Back pain is the initial feature of spinal cord neoplastic disease in about 90% of adult patients. Pain often precedes other symptoms associated with spinal cord compression by approximately 2-4 months. Pain or discomfort may be radicular, localized to the back, or both. Radicular pain suggests nerve root impingement and may be exacerbated with movement or straining/valsalva.
As back pain has many causes, and spinal cord compression can have a subtle presentation,[4] a high index of suspicion may be required when evaluating a patient with back pain and a history of malignancy. An old clinical axiom is that pain from vertebral metastasis (particularly thoracic metastasis) may worsen with recumbent positioning—in contrast to back pain from degenerative joint disease, which may improve with recumbent positioning.
Once symptoms other than pain appear, symptom progression may be rapid. Sensory or motor symptoms that may be referred to the cord include limb paresthesias or focal weakness; the latter may manifest as trouble ambulating or foot drop (often bilateral).
Onset of leg weakness, paresthesias, or bowel or bladder dysfunction in patients with a history of cancer should evoke immediate concern for cord or cauda compression. Paraplegia and bowel or bladder disturbances are usually late findings. Urinary retention is the most common bowel or bladder dysfunction, but retention or incontinence of either urine or stool may occur.
In conus medullaris syndrome, however, sphincter dysfunction and saddle anesthesia may emerge early in the course. Patients with conus medullaris syndrome classically present with low back pain and urinary andIor bowel dysfunction but no gross sensory or motor deficits.
Other historical features that may raise the suspicion for neoplastic cord compression include the following:
Unexplained weight loss
Night pain
Persistent pain that fails to improve despite appropriate workup and therapy
Findings on physical examination correspond to the location of the tumor and the degree and duration of cord impingement. and may include the following:
Local tenderness
Motor weakness
Sensory loss
Reflex changes
Ataxia
Cauda equina syndrome
Tenderness
Severe spinal pain and tenderness is usually the first finding in neoplastic spinal cord disease. Percussion tenderness over the affected spinal region may be present. On straight-leg raising, pain that progresses down the asymptomatic (or less symptomatic) limb may suggest cord compression.
Valsalva maneuvers, such as coughing, sneezing, or straining, may exacerbate radicular back pain from cord compression, but this occurs with other causes of mechanical back pain as well.
Motor weakness
Motor weakness occurs late in the disease process, with thoracic or lumbar lesions causing lower extremity weakness, especially of the flexors, and cervical lesions causing lower extremity weakness as well as upper extremity weakness, especially of the extensors.
Almost one-half of patients with neoplastic spinal cord compression have some paresis, with as many as 15% of patients being paraplegic at the time of diagnosis.
Lax anal sphincter tone is a late sign of spinal cord dysfunction.
Sensory loss
The loss of sensation below a spinal level may be present on exam, usually starting up to five dermatomes below the level of the offending lesion. Lesions above the conus typically spare the sacral dermatomes/saddle area, in contrast to lesions of the cauda equina (see cauda equina syndrome, below)
Reflexes
Spinal cord compression may cause hyperreflexia below the level of the lesion. There may be a period of hyporeflexia early in the course, before the development of hyperreflexia.
Spasticity or hyperreflexia may occur early, or deep-tendon reflexes may be initially hypoactive or absent. The Babinski sign (upward movement of the toe in response to plantar stimulation) may be absent early in the course of compression. As spinal cord compromise advances, hyperreflexia and Babinski reflexes are typically present.
Ataxia
Concomitant development of lower extremity weakness and sensory loss may cause ataxia or a gait disturbance.[4] Rarely, spinal cord neoplasms may present as isolated ataxia not due to sensory or motor deficits
Cauda equina syndrome
Patients with cauda equina syndrome may present with various patterns of lower extremity weakness and sensory loss, depending on which of the multiple nerve roots are compressed at the point where they exit the spinal cord. Manifestations may include bilateral lower extremity radicular pain, in addition to lower back pain. In contrast to lesions above the conus, cauda equina lesions result in hyporeflexia.
Additional findings in certain cases
Consider the following:
Lateral spinal cord compression can produce partial cord disorders, such as Brown-Séquard syndrome (contralateral motor and sensory deficits).
Lesions of the cauda equina and the termination of the spinal cord may cause a combination of upper motor neuron and lower motor neuron signs.
Tumors in the region of the foramen magnum may produce quadriparesis and simulate other causes of diffuse weakness.
If a cervical intramedullary tumor or syrinx (cavity) is present, the unusual clinical picture of isolated sensory loss may be present in the upper extremities.
Magnetic resonance imaging (MRI) of the affected area provides the best definition of spinal lesions and is the procedure of choice. See the image below.
View Image
MRI of plain film above showing intrusion of tumor and vertebral collapse into spinal canal.
With MRI, the entire spine may be visualized rapidly (sagittal images), and images may be obtained in multiple planes for best definition of the lesion, vertebrae, epidural space, and spinal cord. Liberal imaging is recommended, as roughly one third of patients with spinal epidural metastases have multiple spinal metastases.
MRI can usually be used to differentiate malignant disease from a collapsed vertebra secondary to osteoporosis or trauma.
The intervertebral space is usually not involved in tumors of the spine. Obliteration of the disk space is more characteristic in cases of infection.
Diffusion-weighted MRI may be useful in evaluation of epidural neoplastic lesions.[5] An MRI grading scale has been described to quantitate the degree of epidural spinal cord compression.[6]
If MRI cannot be performed, consult a qualified radiologist or oncologist about other imaging options (eg, intrathecal contrast-enhanced myelography, computed tomography, nuclear medicine bone scanning).
CT myelography
CT myelography is the old-school option for patients with suspected cord compression who cannot undergo MRI, for example, those with pacemakers or ocular implants. This test is slightly invasive, as it requires intrathecal administration of contrast.
Plain radiography
Plain radiographs may reveal bony destruction (osteolytic or osteoblastic lesions), vertebral collapse or subluxation, or calcification (associated with a meningioma). Roughly 50% of the bone must be destroyed for the lesion to be visible on plain films.
View Image
Patient with metastatic breast cancer; plain radiograph shows L4 vertebral collapse.
Conventional radiographs do not provide information about spinal cord structure or compression.
Changes are demonstrated on plain films in about 80% of patients with spinal cord tumors. Conversely, findings on plain films are falsely negative in about 20% of cases.
Nuclear medicine
Most tumors (excluding myeloma) exhibit increased activity on nuclear medicine scans.
The presence of a spinal cord tumor is a relative contraindication to the performance of a lumbar puncture, as removal of cerebrospinal fluid in these cases may worsen cord compression. However, in leptomeningeal metastasis, spinal fluid analysis almost always yields abnormal findings, with elevated protein levels and positive cytologic results.
Post-void residual urine volume
If bladder impairment is a concern, have the patient urinate and check the urinary residual volume by catheterization. Volumes greater than 200 mL may suggest a neurogenic bladder.
Spinal cord compression secondary to cancer is an emergency that requires rapid diagnosis and treatment to prevent permanent complications. Even when a cure is not possible, timely diagnosis and treatment may improve the patient's quality of life.
In cancer patients with clinical suspicion of spinal cord compression, dexamethasone should be initiated. This should be followed promptly by surgical decompression, when possible, and radiation therapy.[7] See Follow-up: Further Inpatient Care.
A Cochrane review found a lack of evidence-based guidance around how to correctly position and when to mobilize patients with metastatic spinal cord compression, and whether spinal bracing is effective for reducing pain or improving quality of life. Caution should be used, as mobilization may be hazardous in the presence of spinal instability; further vertebral collapse can occur.[8]
Neurosurgeons traditionally manage spinal cord compression and dysfunction; however, local practices may vary. Oncology, neurology, and radiation oncology staff may be involved in some circumstances.
Dexamethasone administration may acutely preserve neurologic function in patients with epidural spinal cord compression. Opinions regarding dosages vary but recent reviews have recommended doses from 10 to 16 mg, administered either intravenously or orally (IV is more common), followed by 16 mg/day.[9, 10]
Clinical Context:
Dexamethasone is used in the treatment of various inflammatory diseases. The mechanism of action in neurologic function is not completely understood. Some physicians prefer higher-dose regimens (100 mg initial bolus), although this has waned in popularity.
These agents have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, they modify the body's immune response to diverse stimuli. With therapy, tumor-associated edema and cord compression, particularly those caused by metastatic tumors, may diminish.
At the direction of referral physicians, outpatient care may include ongoing chemotherapy, steroid administration, radiation therapy, surgery, or other treatments.
Physical therapy may be necessary. Hospice referral may be indicated in some cases in coordination with the treatment team.
Further inpatient care may include steroid administration, chemotherapy, or surgery ordered at the discretion of attending physicians. Treatment is individualized and depends on tumor type, degree of neurologic function, and other factors.
Surgical decompression provides immediate relief of compression but may contribute to spinal mechanical instability. However, if instability is present from tumor destruction, surgery may be necessary for stabilization. A combination of surgical decompression and radiation may be more effective than radiotherapy alone.[11]
Spratt and colleagues have proposed a multidisciplinary algorithm for management of spinal metastases, using the following treatment options[12] :
Image-guided stereotactic radiosurgery
Separation surgery
Vertebroplasty
Minimally invasive local ablative approaches
Radiation therapy
Radiation treatment to areas of tumor compression should be pursued after appropriate imaging and consultation. Cord compression from an epidural tumor is considered one of the few emergencies in radiation oncology. Spinal cord tolerance to radiation depends on the fraction size and cumulative dose.
Surgical Intervention
Fehlings and colleagues analyzed the outcomes of 142 patients with a single symptomatic metastatic epidural spinal cord compression (MESCC) lesion who were treated surgically and were observed at least up to 12 months. Surgical intervention, as an adjunct to radiation and chemotherapy, was found to provide immediate and sustained improvement in pain-related, neurologic, functional, and health-related quality of life outcomes in patients with at least a 3-month survival prognosis.[13]
The prognosis for recovery of neurologic deficits secondary to spinal cord compression is related to the duration and severity of the impairment at the start of treatment.
Disturbances in sphincter function are associated with a poor prognosis for recovery.
Primary spinal cord neoplasms are usually not metastatic and generally confer a more favorable prognosis for long-term survival than do metastases.
Patients with leptomeningeal metastases have a poor prognosis.
Jesse Borke, MD, FACEP, FAAEM, Associate Medical Director, Department of Emergency Medicine, Los Alamitos Medical Center
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Jeffrey L Arnold, MD, FACEP, Chairman, Department of Emergency Medicine, Santa Clara Valley Medical Center
Disclosure: Nothing to disclose.
Chief Editor
Barry E Brenner, MD, PhD, FACEP, Professor of Emergency Medicine, Professor of Internal Medicine, Program Director for Emergency Medicine, Sanz Laniado Medical Center, Netanya, Israel
Disclosure: Nothing to disclose.
Additional Contributors
Edmond A Hooker, II, MD, DrPH, FAAEM, Associate Professor, Department of Health Services Administration, Xavier University, Cincinnati, Ohio; Assistant Professor, Department of Emergency Medicine, University of Cincinnati College of Medicine
Disclosure: Nothing to disclose.
J Stephen Huff, MD, FACEP, Professor of Emergency Medicine and Neurology, Department of Emergency Medicine, University of Virginia School of Medicine
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