Spinal Cord Injury

Overview

A spinal cord injury is regarded by many as one of the most devastating injuries. There are different types of spinal cord injuries depending on the region of the spinal cord and spinal level involved, and the injury may be complete or incomplete. There are different types of spinal cord injuries, or syndromes, based on the region of the spinal cord involved. Anterior cord syndrome is the most common, and most severe, as it affects the anterior (front) portion of the spinal cord which controls motor function and the majority of sensation. Central cord syndrome typically occurs as a result of a cervical hyperextension injury in an elderly person, causing damage to the middle portion of the spinal cord. This usually causes a patient to have increased weakness and numbness in the hands and arms compared to the legs. Brown-Séquard syndrome results from an injury to one side of the spinal cord, causing ipsilateral (same side) weakness, and contralateral (opposite side) numbness. This syndrome has the best prognosis and chance for recovery. Patients who have sustained a complete injury rarely, if ever, recover significant strength or sensation below the level of injury. Paraplegia is defined as profound or complete loss of motor function (strength) of the legs. Quadriplegia is defined as profound or complete loss of motor function (strength) of the arms and legs. Tetraplegia is defined as profound or complete loss of motor function (strength) of the head, neck, arms, and legs, and requires the patient be on a ventilator to breathe.

Causes

The most common cause of a spinal cord injury is spine trauma caused by a motor vehicle accident. Other causes are falls, violence, and sports activities. The abrupt impact and/or twisting of the neck or back that occurs in a millisecond during the trauma can cause the spine bones to crack or the ligaments to rupture, or both, also causing damage to the spinal cord and neurologic structures. The resultant spinal cord injury involves a primary and secondary injury process. The primary cause is the initial mechanical impact, compression, and contusion resulting in damage to nerve cells, myelin, blood vessels, and supporting bone structures. The secondary injury process involves swelling and hemorrhage, which leads to increased free radicals and decreased blood flow, causing even greater cell membrane dysfunction and cell death.

Symptoms

Patients with associated spine fractures typically have significant, localized neck or back pain. Patients with incomplete spinal cord injuries may complain of pain in other areas and not notice the severity of neck of back pain. Patients who have an incomplete spinal cord injury and continued neurologic compression or irritation will have numbness or weakness in the arms and/or legs. There may or may not be associated radiating pain symptoms. Patients with a complete spinal cord injury will have complete loss of strength and sensation in the legs and possibly the arms depending on the level of injury. Upper cervical spine fractures and spinal cord injuries can affect the neurologic control of breathing, and patients may complain of difficulty breathing or the inability to take a deep breath.

Physical Findings

Patients with a spine fracture and spinal cord injury will typically demonstrate profound tenderness and spasm over the injured region. There is often visible swelling and ecchymosis (bruising) over the fracture site. If the fracture/dislocation is severe, there will be a visible and palpable "step-off", meaning the bones are not lined up properly which can be seen and felt by the examiner. Patients will have complete loss of strength and sensation in the setting of a complete spinal cord injury. Deep tendon reflexes may be diminished or absent. Pulses and vascularity of the arms and legs should be normal.

Imaging Studies

Plain x-rays of the spine are essential to adequately evaluate a patient with spinal cord injury and spine fracture. It is sometimes difficult to see a non-displaced or minimally displaced fracture or instability, therefore a Computed Tomography (CT) scan is usually ordered. A Magnetic Resonance Imaging (MRI) test is useful to evaluate the severity of nerve compression or spinal cord injury, but is less accurate at detecting a fracture than a CT scan. A MRI test should be obtained in patients with a spinal cord injury. A MRI should generally be obtained before performing a reduction procedure (closed or operative) in neurologically intact (or partially intact) patients with a cervical fracture/dislocation.

Laboratory Tests

There are no laboratory tests used to diagnose spinal cord injury. Occasionally, specific tests are ordered to rule out infection or other causes of spinal cord dysfunction.

Diagnosis

The diagnosis of a spinal cord injury is fairly straight-forward in most patients. However, it is important to quickly and accurately assess the patient and the cause of the spinal cord injury, and to reduce a spine dislocation and/or surgically decompress and stabilize the fractured vertebrae if present.

Treatment Options

The treatment of a spinal cord injury can be divided into four categories: pre-hospital care, emergency room care, operative and hospital care, and rehabilitation. Pre-hospital care focuses on extrication of the patient from an accident in a safe manner, taking adequate spine precautions to stabilize the neck in a collar and spine on a backboard to avoid additional spine and spinal cord injury. Emergency room care of a spinal cord-injured patient dictates that a patient receive Methylprednisolone intravenously as prescribed by the NASCIS guidelines. A patient should be appropriately and efficiently evaluated, so as to diagnose the underlying cause of the spinal cord injury and neurologic deficit. Urgent treatment, whether it be a closed reduction of a cervical dislocation or surgical decompression if indicated, is warranted as soon as the patient is medically stable to undergo such a procedure. Aggressive mobilization and rehabilitation should be started immediately in the post-operative period, with twice daily physical therapy either in the in-patient or out-patient setting. Patients with tetraplegia or severe quadriplegia generally require life-long assistance with activities of daily living and routine self-care.

Selected Bibliography

Anderson PA, Bohlman HH: Anterior decompression and arthrodesis of the cervical spine: long-term improvement. Part II. Improvement in complete traumatic quadriplegia. J Bone Joint Surg Am 1992;74:683.

Bracken MB, Shepard MJ, Collins WF et al. A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury: results of the Second National Acute Spinal Cord Injury Study. N Engl J Med 1990;322:1405.

Bracken MB, Shepard MJ, Holford TR, et al. Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury: results of the Third National Acute Spinal Cord Injury Randomized Controlled Trial. National Acute Spinal Cord Injury Study. JAMA 1997;277:1597.

Coleman WP, Benzel D, Cahill DW, et al. A critical appraisal of the reporting of the National Acute Spinal Cord Injury Studies (II and III) of methylprednisolone in acute spinal cord injury. J Spinal Disord 2000;13:185.

Hughes JT. The Edwin Smith Surgical Papyrus: an analysis of the first case reports of spinal cord injuries. Paraplegia 1988;26:71.

Kakulas BA. The applied neuropathology of human spinal cord injury. Spinal Cord 1999;37:79.

Kwon BK, Tetzlaff W, Grauer JN, et al. Pathophysiology and pharmacologic treatment of acute spinal cord injury. Spine J 2004;4:451.

Rizzolo SJ, Vacarro AR, Cotler JM: Cervical spine trauma. Spine 1994;19:2288.

Sekhon LH, Fehlings MG. Epidemiology, demographics, and pathophysiology of acute spinal cord injury. Spine 2001;26S:2. Tator CH, Duncan EG, Edmonds VE, et al. Changes in epidemiology of acute spinal cord injury from 1947 to 1981. Surg Neurol 1993;40:207.