Ohhh My Neck!

I am most certain all of us can relate neck pain at some point in our life!  Whether it is from wearing a heavy fire helmet for hours at a structure fire, physical therapy, a car accident, a direct hit to the neck, or various other mechanisms; neck pain is rather common.  However, have you heard of neck pain from a traumatic carotid artery dissection?  My guess is probably not, being this is a rather rare diagnosis, occurring only 0.64% of the time in patients who were admitted with blunt trauma according to one study in A Review of Blunt Cerebrovascular Injuries, n.d.

Unfortunately, traumatic carotid artery dissections are most common in our pediatric population; specifically, those less than six years of age, which compromise 73% of these dissections according to Carotid Dissection in Blunt Neck Trauma, n.d.  There are a few specific factors that put children at a greater risk for this phenomenon.  A child’s larger head to body ratio and cranial cervical instability both contribute to increased risk for carotid overstretching.  However, it is not always about anatomy.  Sometimes a carotid artery dissection occurs from a twisting/ shearing motion of the neck, direct trauma to the neck as aforementioned, chiropractic manipulation, whiplash, and even vigorous coughing/sneezing!  Other factors that can predispose someone to this type of injury include underlying etiologies (such as Ehler-Danlos Syndrome type IV, Marfan’s Syndrome, and Fibromuscular Dysplasia according to Gdynia et al., 2008), and weak/underdeveloped soft tissues and ligaments.

Carotid dissections can vary in degree of severity from minor to severe.  Here is a chart describing the grading scale for a vascular injury, with full vessel transection, or grade V the worst grade according to Table 2 in A Review of Blunt Cerebrovascular Injuries (@ C.E.):

Table 2. Injury Grading Scale4

GradeInjury
I Intimal irregularity or dissection
II Dissection or intraluminal hematoma with ≥25% luminal narrowing, intraluminal clot, or visible intimal flap
III Pseudoaneurysm
IV Complete occlusion
V Transaction with active extravasation

If we think our patient could be experiencing a carotid dissection related to blunt trauma, we must take into consideration the potential for a cervical spine or spinal cord injury (with or without radiographic evidence) associated with this diagnosis as well.  According to Biffl et al., 2002, patients with blunt carotid injury were more likely to have a brain injury, facial fracture, or basilar skull fracture.  Thus, it is imperative that a cervical collar and spine immobilization occur when appropriate, with strict monitoring to take into consideration the amount of swelling and internal anatomical changes that are occurring.

So, how can we identify this injury pattern?  The signs and symptoms can be very different from person to person and at times, may not show up for days.  Children are particularly at high risk for a missed injury as they may remain asymptomatic.  Other times it is very apparent the patient has experienced a higher-grade vascular injury resulting in periods of unconsciousness, significant neurological deficits, or even cardiac arrest.  According to Cervical (Carotid or Vertebral) Artery Dissection, n.d., head and neck pain is generally reported.  On physical exam, you may hear a bruit over the carotid artery or you may see an expanding hematoma.  The patient may exhibit any number of stroke syndromes including hemiplegia or central vertigo, depending on the vessel involved.  Keep in mind, the subset of patients who do experience a stroke after a lower grade carotid dissection have a mortality rate of 25% with most symptoms developing within 72 hours of traumatic injury according to Rigby & Agrawal, 2022.

In summary, as healthcare providers we must prevent any further damage by protecting the cervical spine with appropriate immobilization while also attending to any life threats as you would any other patient: control hemorrhage, assess/maintain the airway, ensure adequate breathing and ventilation and maintaining circulation.  We should plan for rapid decline in these patients with blunt trauma to the neck and anticipate the potential for a difficult airway related to swelling, hematoma formation, and any other individual factors.  We must transport them to a level I/II trauma center that can offer a myriad of services for these patients require.  Please keep this differential diagnosis in mind as you encounter a trauma patient with appropriate mechanism or risk factors. Prompt recognition and appropriate treatment could ensure a positive outcome for the patient.

By Amanda Quinn, RN, EMT-P
Flight Nurse, West Michigan Air Care

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