Cervical Strain (Whiplash) Workup

Updated: Dec 02, 2019
  • Author: Warren Magnus, DO; Chief Editor: Trevor John Mills, MD, MPH  more...
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Workup

Imaging Studies

Radiologic studies are often not indicated acutely in the management of cervical strain. However, given the catastrophic sequelae of cervical spinal cord injury, many emergency physicians have a low threshold for ordering cervical spine radiographs in patients with blunt trauma. However, the literature supports that very few of these patients actually have a cervical spine fracture, and the past pattern of use of radiography has not been efficient. While cervical spine radiography is a low-cost procedure, it adds substantially to overall healthcare costs given the high volume of its use, in addition to leading to considerable discomfort for patients immobilized by a backboard and hard collar while awaiting radiography.

Clinical evaluation and history have been proven effective in guiding the need for radiography to further evaluate patients with possible clinically significant cervical spine injury. The National Emergency X-Radiography Utilization Study (NEXUS) Low-Risk Criteria (NLC) state that cervical spine radiography is indicated for patients with trauma unless they meet all of the following 5 criteria [7, 4, 5, 8] :

  • No posterior midline cervical spine tenderness

  • No evidence of intoxication

  • A normal level of alertness

  • No focal neurologic deficit

  • No painful distracting injuries

The Canadian C-Spine Rule was designed in 2001 to help assess the need for imaging in people who present to the ED with a cervical spine injury after blunt trauma. It was developed for use in adults who are alert (score of 15 on the Glasgow Coma Scale) and stable and in whom a clinically important cervical spine injury is a concern. The Canadian C-Spine Rule is based on 3 high-risk criteria (age ≥65 years, dangerous injury mechanism, paresthesia in extremities), 5 low-risk criteria (simple rear-end motor vehicle collision, sitting position in the ED, ambulatory at any time, delayed onset of neck pain; absence of midline cervical-spine tenderness), and the ability of the person to rotate the neck. [7, 4, 5, 8]

High-speed helical CT technology has made it possible to rapidly perform cervical spine CT with reconstruction and is an efficient and cost-effective method of screening for cervical injury in high-risk trauma patients. For high-risk patients, severe head injury, high-energy injury mechanism of motor vehicle collision, victims of motorcycle collision, and pedestrians struck by automobiles, CT has higher sensitivity than plain films in the detection of fractures, with less chance of a missed fracture leading to severe neurologic injury, such as paralysis. Furthermore, CT is a cost-effective initial screening strategy in patients with high risk of injury, neurologic deficits, or severe head injury when long-term time-frame costs are considered.

Computed tomography has been found to be effective in the detection of clinically significant cervical spine injuries in adults with a neurologic deficit or cervical spine pain. In one study, the sensitivity and specificity of CT for detecting cervical spine injury was 90.9% and 100%, respectively. For clinically significant cervical spine injuries, the sensitivity was 100% and specificity was 100%. [12, 13, 14, 15, 16, 17]

MRI is generally more effective in evaluating spinal cord and ligamentous injury. In the setting of multiple injury, negative findings on CT scans and lateral plain film still warrant an MRI to eliminate instability. In patients who are obtunded or difficult to examine or in patients with persistent focal neurologic deficits or radicular pain, MRI may be necessary to rule out cord injury. MRI is also indicated in patients if new neurologic symptoms develop after the patient's initial presentation to the ED. Although CT with reconstruction is highly sensitive for clinically significant cervical injury, subsequent MRI can confirm significant ligamentous injury. [14, 15, 18]

Even with a normal static radiologic evaluation, a second assessment must be made in high-risk patients to ensure there is no ligamentous instability iand to assess the risk of myelopathy developing from a destabilizing cervical injury. Muscle spasm and limited range of motion secondary to pain after an injury of significant mechanism can hide an anterior subluxation and unstable ligamentous injury. Further radiographic evaluation with dynamic flexion/extension radiography should be arranged on an outpatient basis within 1 week of injury in patients with continued pain or tenderness.