Acute Cervical Spinal Cord Injury — Diagnosis & Management

Patients with acute cervical spinal cord injury present complex clinical challenges. These injuries may result in motor and sensory deficits and also in cardiovascular and respiratory perturbations. Increased attention to critical care support has led to improved survival and recovery in many patients. The methods and technology used to diagnose and classify these injuries as well as medical and surgical treatments have evolved significantly in recent decades. We review important aspects of the diagnosis and acute care of patients with traumatic cervical spinal cord injuries, emphasising the recent evidence.

Spinal cord injury (SCI) can be a devastating disease that presents multiple challenges in both acute and chronic phases. Managing patients with SCIs requires a multidisciplinary team that usually includes a neurosurgeon or orthopaedic surgeon, neurologist and physiotherapist. Although our ability to treat injuries surgically has advanced in recent years from a standpoint of spinal column stabilisation, the overall motor and sensory recovery in patients with a severe SCI has not changed. Extensive research is focussing on improving outcomes using stem cells and other adjuvant therapies, such as direct electrical stimulation.1 As this research comes to affect the field, we review the basic diagnostic and treatment paradigms reflected in the field’s vast literature. To cite: Ropper AE, Neal MT, Theodore N. Pract Neurol 2015;15:266–272.

The US National SCI Statistics Center estimated the number of people living with SCI in the USA as ∼273 000. 2 Nearly half of these injuries occurs in young people (aged 16–30 years). Published reports of SCI incidence in the USA vary from 25 to 59 new cases per million population per year with an average of 40 per million, translating to approximately 12 400 new SCI cases in 2010. 3 In the UK and Ireland, it is estimated that 50 000 people are living with SCI with an annual health care cost of more than £1 billion. 4 Falls are a common cause of injury in the elderly, whereas motor vehicle crashes, violence and sports are the common causes of SCI in children and the younger adult populations.

3 While it is possible for an SCI to occur in any region of the spine, we choose here to focus on cervical spine injury. Injury to the cervical spine can be the most severe SCI—aside from possible quadriplegia, breathing can be impaired from neurological injury above C5. The cervical spine is especially vulnerable to injury given the relative axial alignment of the facet joints, which require less force to dislocate compared with the thoracic or lumbar spine. In addition, the neck has relatively little external support —compared with the thoracic spine that has the rib cage for stabilisation—predisposing the cervical spine to injury.

Although this review focuses mainly on the cervical spine, we also discuss general principles that apply to traumatic thoracic fractures. Significant trauma to the lumbar spine is less common and results in root injuries, which are neurologically distinct from cervical and thoracic trauma.

There has been substantial investigation into the types of imaging to be obtained for trauma patients to evaluate possible traumatic spinal pathology. The Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons have done an excellent service by summarising the vast data in the literature regarding radiographic assessment of the spine in trauma. 15 The committee divided patients into three groups: (1) awake, asymptomatic patients; (2) awake, symptomatic patients and (3) obtunded patients. There are different imaging and initial treatment algorithms for patients falling into each category, supported by class I evidence.

Awake patients with no neurological symptoms or neck pain, in the absence of distracting injuries, who can perform a full neck range of motion without pain, do NOT require imaging or continued cervical spine immobilisation. This guideline was investigated by the National Emergency X-Radiography Utilization Study Group (NEXUS). Their trial prospectively studied a total of 34 069 blunt trauma patients of whom 4309 were asymptomatic. 16 All patients underwent standard three-view cervical spinal radiographs supplemented with CT as needed.

Five criteria had to be met for the patient to be classified as having a low probability of injury: no midline cervical tenderness, no focal neurological deficit, normal alertness, no intoxication and no painful distracting injury. These criteria alone identified 810 of the 818 patients who had a cervical spinal injury, with a sensitivity of 99%. Although not 100% sensitive, clinicians can easily apply the NEXUS criteria and these should serve as a guideline when deciding whether to request further cervical spine imaging for an awake and asymptomatic patient.

In awake but symptomatic patients, traditional three-view radiographs (anteroposterior, lateral and open-mouth odontoid view) should be obtained ONLY if it is not possible to obtain a high-quality CT scan. If CT imaging is readily available, as it is in nearly all trauma centres, then CT of the cervical spine should be the initial imaging study. If the CT Pract Neurol: first published as 10. 1136/practneurol-2015-001094 on 18 May 2015. Downloaded from http://pn. bmj. com/ on June 25, 2023 by guest. Protected by copyright. for any suspected SCI.

Although there is no class I or II evidence supporting the use of a rigid cervical collar in suspected spinal trauma, there are clear anatomical, anecdotal and biomechanical advantages to limiting neck movement in these circumstances. The older practice of head immobilisation with sandbags and tape on a backboard should be used in selected cases of occipitocervical dislocation (once diagnosed) but offers no advantage in most other cervical spine injuries. There does not appear to be a major difference in the biomechanical constraints of different rigid cervical collars in cadaveric studies. 6 We believe that a rigid collar should be applied to the neck with manual in-line stabilisation while minimising cervical spine displacement.

Spinal immobilisation is a priority of the prehospital trauma algorithms and leads to an improved outcome. 7 However, class II evidence suggests that patients with penetrating trauma who had prehospital spinal immobilisation have a worse outcome. 8 Because the process of immobilisation delayed life-saving resuscitation, patients in the study who were immobilised had nearly twice the morbidity and mortality as those penetrating trauma patients who did not have full immobilisation. While cervical collars and backboards provide an important tool to reduce further neurological injury, they have their own inherent risks and complications. Among these are high risks of aspiration,9 pressure sores10 and increased intracranial pressure.

11 Practitioners must recognise these risks and understand the need to remove immobilising devices as soon as safety allows.

There is strong evidence from physiological animal studies to show that hypotension and hypoxaemia both contribute to secondary injury after an SCI. As occurs with head injury, the spinal cord loses the ability to autoregulate after injury, and vasoreactivity may contribute to local hypoperfusion. This can be significantly exacerbated by spinal shock, which leads to the loss of peripheral vascular tone (among other effects) and further hypotension and hypoperfusion. This may lead to increased secondary damage to the spinal cord around the site of injury in the hours and days after the trauma. Therefore, clinicians must focus on avoiding hypoxia and hypotension in the acute postinjury period: this can be best achieved in an intensive care unit.

18 Patients with high-cervical SCI require careful airway management with careful and expedient intubation. Avoiding catastrophic airway loss is critical in the acute postinjury period. 19 Careful ventilator and airway management should reduce the chance of pneumonia in this precarious patient population. There is still controversy regarding blood pressure management in acute cervical SCI. The abundant class III evidence suggests that an elevated mean arterial pressure over 85 or 90 mm Hg results in independently improved outcomes.

20–22 The retrospective nature of the data in the literature regarding optimal duration of treatment and the target mean arterial pressure makes elevation of this pressure in patients with SCI purely a recommendation rather than a steadfast guideline. We believe that future studies will lend more concrete credence to this approach. 23 We generally treat patients with cervical SCI with norepinephrine for 7 days after the injury to maintain a mean arterial pressure between 85 and 90 mm Hg. The aggressiveness of this treatment is anecdotally titrated based on the severity of the patient’s injury and any associated or pre-existing cardiopulmonary comorbidities.

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