Emergency Management of Non-traumatic Spinal Cord Compression: Focus On Early Intervention

Introduction

Non-traumatic spinal cord compression can be of traumatic or non-traumatic origin. Lack of early intervention increases morbidity rates, and quality of life is hugely affected. Non-traumatic causes can be infectious, inflammatory, neoplastic, or degenerative. The spinal cord is designed to give the skeleton structural support and consists of many soft tissues, bones, and nerve roots. The spine consists of 33 vertebrae (small bones): seven cervical, 12 thoracic, five lumbar, five sacral (fused), and four coccygeal (fused) forming a spinal canal. The spinal cord roughly measures about 40 cm in length and extends from the foramen magnum (a cavity at the base of the skull through which the spinal cord passes) to the L1 to L2 vertebrae (the last part of the spinal cord).

What Causes Non-traumatic Spinal Cord Compression?

• Spondylosis (degenerative changes) is a common age-related problem affecting the intervertebral discs, facet joints, or vertebral bodies, causing stenosis due to the narrowing of the spinal canal, affecting the blood vessels and nerves in the vicinity leading to compression of the spinal cord (myelopathy).

• Cervical spondylosis is the most common causative agent of spinal cord compression, especially after the age of 55 years in adults.

• Highly comorbid conditions that require prolonged hospitalization and the metastatic effect of malignancies like lung cancer, multiple myeloma, and prostate cancer exhibit a high risk of developing metastatic spinal cord compression (MSCC).

• Rarely, a spinal epidural abscess can lead to spinal cord compression.

• Spontaneous spinal epidural hematoma (SSEH) is caused by oral anticoagulant and vitamin K therapy to treat non-valvular atrial fibrillation (irregular heartbeat), deep venous thrombosis (DVT) or pulmonary embolism (PE) can lead to compression of the spinal cord in rare cases.

What Is the Pathomechanism Behind Non-traumatic Spinal Cord Compression?

• Degenerative spondylosis causes the narrowing of the spinal canal, causing the compression of the spinal elements, including vertebrae, blood vessels, and nerves present nearby.

• Due to the compression of spinal elements, myelopathic or neurological symptoms like non-specific neck and back pain can manifest.

• Stenosis of the spinal cord due to direct compression of nerves and ischemia due to compression of blood vessels can lead to further complications.

• MSCC (metastatic spinal cord compression) results from the hematogenous spread of malignancy to the spinal cord. The malignant spread to the spinal column, causing compression of the spinal cord, blood vessels, and thecal sac and resulting in myelopathic symptoms.

• MSCC usually affects the thoracic spine, followed by the lumbar and cervical vertebrae.

• A spinal epidural abscess (SEA) is caused by direct infection spreading from the soft tissue or bony infections like psoas abscess, vertebral osteomyelitis, or through direct inoculation from a spinal procedure resulting in the compression of the spinal cord.

• Risk factors of SEA include:

• IV (intravenous) drug abuse.

• Dental abscess.

• Infection following an epidural catheter placement.

• Infective endocarditis (bacterial infection enters the bloodstream and gets lodged in the lining of a heart valve or a blood vessel).

• Paraspinal analgesic and steroid injection.

• Diabetes.

• Immunosuppression caused due to HIV medications.

• Alcoholism.

• Staphylococcus aureus is most commonly isolated from the infections causing spinal epidural abscesses. Escherichia coli, Streptococcal species, and Pseudomonas aeruginosa are also involved in the pathological process.

• SEA causes compression by the abscess impinging on the neural elements or by inflammatory vascular thrombosis affecting the blood supply and subsequent impaired neurological functions.

• Neuraxial analgesia can result in a spinal epidural hematoma (SEH) due to the puncture into the spinal canal leading to subdural and subarachnoid hemorrhage.

• Due to the hemorrhage formation, increased pressure, spinal cord ischemia, and infarction in the spinal canal result in myelopathic manifestations.

• Risk factors of SEH include:

• Presence of preexisting coagulopathy (due to anticoagulant therapy, advanced renal (kidney) disease, thrombocytopenia (reduced platelet count), and preeclampsia (a pregnancy complication associated with high blood pressure).

• Old age.

• Spinal abnormalities.

What Are the Clinical Features of Non-traumatic Spinal Cord Compression?

Compression of the spinal cord may damage the nerves situated in the vicinity. These nerve innervations are responsible for various locomotor movements of the body and other functions. The symptoms of myelopathy (spinal cord compression) depend on the area of the spinal cord affected, which include,

• Non-specific pain involving the neck and back.

• Tingling sensation, numbness, or weakness in the arms, hands, legs, or feet.

• Having problems in performing motor skills like buttoning a shirt or holding small objects.

• Balance or coordination problems.

• Abnormal reflexes of extremities.

• Impaired bladder and bowel control.

• Changes in sexual function and fertility.

• The patient finds difficulty in breathing, coughing, and expelling secretions.

• Paralysis results due to the respective nerve compression.

How Is Non-traumatic Spinal Cord Compression Diagnosed?

• Myelopathy is caused by degenerative spondylotic changes is best detected by an MRI (magnetic resonance imaging) scan as the spinal cord pathology is best assessed and is minimally invasive.

• CT (computed tomography) of spinal cord compression is also preferred as an alternative to MRI. CT scan is advantageous in detecting myelopathy as it provides a quantitative evaluation of the narrowing spinal canal and also gives detailed information on soft tissues and calcification of bony structures.

• Gadolinium contrast-enhanced MR imaging is regarded as the gold standard diagnostic tool to rule out metastatic spinal cord compression (MSCC).

• CT myelography in the case of MSCC is advised only when MRI is contraindicated as the X-rays are not sensitive to detect metastatic disease, and soft tissue details obtained are less informative.

• Laboratory investigations like CRP (C-reactive protein) and ESR (erythrocyte sedimentation rate) are useful in diagnosing suspected cases of SEA (spinal epidural abscess).

How Is Non-traumatic Spinal Cord Compression Treated?

• Mild cases of cervical spondylosis causing spinal compression can be treated with physiotherapy and analgesics like non-steroidal anti-inflammatory agents and muscle relaxants. The patient is advised to limit physical activities which aggravate the condition.

• Epidural steroid injections can also be given as a part of the conservative management of spinal cord compression.

• A periodic neurological examination is carried out to keep a check on the progression of the condition.

• Surgical decompression is indicated for moderate to severe cases and when conservative treatment fails.

• MSCC (metastatic spinal cord compression) with neurologic involvement is treated with Dexamethasone (glucocorticoid) administration.

• Dexamethasone helps in decreasing spinal cord edema, and also improves neurological functioning, and relieves pain.

• In case of spinal epidural abscess, appropriate antibiotic therapy is instituted as soon as possible. The standard regimen involves Ceftriaxone, of 2 g IV daily, and Vancomycin of 15 to 20 mg/kg IV for every eight to 12 hours administered to treat Staphylococcus aureus infection, and SEA often requires surgical decompression procedures.

Conclusion

Non-traumatic spinal cord compression can result from various causes and poses a challenge to emergency health professionals in detecting the case early. Delayed diagnosis can lead to death or permanent neurological impairment, affecting the normal functioning of the human body. Early detection helps in decreasing mortality rates and improves the quality of life, too. It is the responsibility of a health professional to identify early signs and symptoms of spinal cord compression like back pain, motor weakness, impaired sensory reflexes, or difficulties in balancing and altered gait associated with exposure to risk factors, which positively affect the prognosis and contribute to better patient outcomes.