Management of spinal cord injuries is a fundamental EMS skill, challenging providers and bringing risks to patients. Ensuring that we do not immobilize needlessly--or fail to immobilize when indicated--requires a thorough assessment.
You are called to the scene of a rollover MVC. Your patient apparently self-extricated from the vehicle prior to your arrival and is ambulatory at the scene. He is calm and alert, responds to all questions appropriately and cooperates fully with your physical exam. Assessment findings and vital signs are:
- Point tenderness and deformity to the left forearm and superficial lacerations to both hands;
- Denies loss of consciousness;
- No signs of mental impairment or intoxication;
- Denies posterior midline cervical spine tenderness;
- Exhibits intact sensory and motor function in all extremities;
- Pulse: 112 bpm;
- Respirations: 20 bpm;
- BP: 136/74.
The spine is composed of five discrete regions: cervical, thoracic, lumbar, sacrum and coccyx. Of these, the cervical and lumbar regions--the two least supported by other elements of the skeleton--are the most commonly fractured.
Branching from the spinal cord between each vertebrae are 31 pairs of spinal nerves composed of sensory, motor and autonomic fibers. Each of these nerve pairs is responsible for a discrete body region known as a dermatome. The efferent, or motor, fibers carry impulses from the central nervous system to muscles or organs, while afferent sensory fibers carry impulses from the muscles or organs to the CNS for interpretation. Motor or sensory deficits in the dermatomes innervated by these nerves are strong clues to damage to these nerves and/or their corresponding vertebrae.
The National Emergency X-radiography Utilization Study (NEXUS), designed to limit the number of unnecessary cervical spine x-rays, defined a set of clinical criteria to identify those patients at low risk of spinal injury.1 The NEXUS exam criteria are as follows:
- No evidence of intoxication--The mere smell of alcohol metabolites on a patient's breath does not always indicate intoxication, but caution is warranted.
- Normal level of alertness--Patients must exhibit present mental capacity to participate in the exam, and follow instructions without hesitation.
- No midline posterior cervical spine tenderness--Walk your fingers down the cervical spine from the base of the skull to between the shoulder blades, assessing for point tenderness.
- No focal neurological deficits--Weakness is the most common neurological deficit, and may be bilateral or confined to one extremity. Numbness is relatively rare and is most commonly described as tingling, burning or a "funny feeling." Have the patient squeeze your hands and flex both feet. Touch all four extremities and check for sensory deficits. The Canadian C-spine Rule (CCR) adds several criteria that place patients at higher risk of a spinal cord injury:2
- Age over 65;
- Significant mechanism of injury;
- Significant injury above the clavicles.
Studies indicate that NEXUS and CCR are more than 99% accurate at ruling out cervical spine injury, and thus the need for an x-ray. In the field, those same criteria can be used effectively to determine the need for spinal motion restriction.
Spinal Injury Patterns
Brown-Séquard syndrome results from an incomplete hemisection of the spinal cord, most often from penetrating trauma. The syndrome is characterized by loss of motor function and proprioception (ability to sense position, location, orientation and movement) on the side of the lesion, and contralateral loss of temperature and pain sensation.
Central cord syndrome most often results from hyperextension of the cervical spine, and presents with greater weakness in the upper limbs than in the lower limbs. Some CCS patients still have enough motor function in the lower extremities to enable them to walk. Bladder dysfunction may be present, most commonly presenting as an inability to urinate.