Spinal cord injury (SCI) is an insult to the spinal cord resulting in a change, either temporary or permanent, in the cord’s normal motor, sensory, or autonomic function. Patients with SCI usually have permanent and often devastating neurologic deficits and disability. The most important aspect of clinical care for the SCI patient is preventing complications related to disability. Supportive care has shown to decrease complications related to mobility. Further, in the future our increasing fund of knowledge of the brain-computer interface might mitigate some of the disabilities associated with SCI.
Signs and symptoms
The extent of injury is defined by the American Spinal Injury Association (ASIA) Impairment Scale (modified from the Frankel classification), using the following categories:
A = Complete: No sensory or motor function is preserved in sacral segments S4-S5
B = Incomplete: Sensory, but not motor, function is preserved below the neurologic level and extends through sacral segments S4-S5
C = Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have a muscle grade of less than 3
D = Incomplete: Motor function is preserved below the neurologic level, and most key muscles below the neurologic level have a muscle grade that is greater than or equal to 3
E = Normal: Sensory and motor functions are normal
Definitions of complete and incomplete spinal cord injury, as based on the above ASIA definition, with sacral-sparing, are as follows:
Complete: Absence of sensory and motor functions in the lowest sacral segments
Incomplete: Preservation of sensory or motor function below the level of injury, including the lowest sacral segments
Signs of respiratory dysfunction include the following:
Loss of ventilatory muscle function from denervation and/or associated chest wall injury
Lung injury, such as pneumothorax, hemothorax, or pulmonary contusion
Decreased central ventilatory drive that is associated with head injury or exogenous effects of alcohol and drugs
A direct relationship exists between the level of cord injury and the degree of respiratory dysfunction, as follows:
With high lesions (ie, C1 or C2), vital capacity is only 5-10% of normal, and cough is absent
With lesions at C3 through C6, vital capacity is 20% of normal, and cough is weak and ineffective
With high thoracic cord injuries (ie, T2 through T4), vital capacity is 30-50% of normal, and cough is weak
With lower cord injuries, respiratory function improves
With injuries at T11, respiratory dysfunction is minimal; vital capacity is essentially normal, and cough is strong
See Clinical Presentation for more detail.
The following laboratory studies can be helpful in the evaluation of spinal cord injury:
Arterial blood gas (ABG) measurements – May be useful to evaluate adequacy of oxygenation and ventilation
Lactate levels – To monitor perfusion status; can be helpful in the presence of shock
Hemoglobin and/or hematocrit levels – May be measured initially and monitored serially to detect or monitor sources of blood loss
Urinalysis – Can be performed to detect any associated genitourinary injury
Imaging techniques in spinal cord injury include the following:
Plain radiography – Radiographs are only as good as the first and last vertebrae seen, therefore, radiographs must adequately depict all vertebrae
Computed tomography (CT) scanning – Reserved for delineating bony abnormalities or fracture; can be used when plain radiography is inadequate or fails to visualize segments of the axial skeleton
Magnetic resonance imaging (MRI) – Used for suspected spinal cord lesions, ligamentous injuries, and other soft-tissue injuries or pathology
See Workup for more detail.
Emergency department care
Airway management – The cervical spine must be maintained in neutral alignment at all times; clearing of oral secretions and/or debris is essential to maintaining airway patency and preventing aspiration
Hypotension – Hypotension may be hemorrhagic and/or neurogenic in acute spinal cord injury; a diligent search for occult sources of hemorrhage must be made
Neurogenic shock – Judicious fluid replacement with isotonic crystalloid solution to a maximum of 2 L is the initial treatment of choice; maintain adequate oxygenation and perfusion of the injured spinal cord; supplemental oxygenation and/or mechanical ventilation may be required
Head injuries – Amnesia, external signs of head injury or basilar skull fracture, focal neurologic deficits, associated alcohol intoxication or drug abuse, or a history of loss of consciousness mandates a thorough evaluation for intracranial injury, starting with noncontrast head CT scanning
Ileus – Placement of a nasogastric (NG) tube is essential; antiemetics should be used aggressively
Pressure sores – To prevent pressure sores, turn the patient every 1-2 hours, pad all extensor surfaces, undress the patient to remove belts and back pocket keys or wallets, and remove the spine board as soon as possible
Treatment of pulmonary complications and/or injury in patients with spinal cord injury includes supplementary oxygen for all patients and chest tube thoracostomy for those with pneumothorax and/or hemothorax.
Emergent decompression of the spinal cord is suggested in the setting of acute spinal cord injury with progressive neurologic deterioration, facet dislocation, or bilateral locked facets. The procedure is also suggested in the setting of spinal nerve impingement with progressive radiculopathy, in patients with extradural lesions such as epidural hematomas or abscesses, and in the setting of the cauda equina syndrome.
See Treatment and Medication for more detail.