Blunt cerebrovascular injuries include cervical carotid dissections and vertebral artery dissections that are due to blunt trauma. Although the overall incidence is low, dissections remain a common cause of stroke in children, young adults, and trauma patients. Symptoms of dissection, such as headache, neck pain, and dizziness, are commonly seen in the emergency department, but may not be apparent in the obtunded trauma patient or may not be recognized as being due to a dissection. A missed diagnosis of cervical artery dissection can result in devastating neurologic sequelae, and emergency clinicians must act quickly to recognize this diagnosis and begin treatment as soon as possible. This supplement reviews the application of advanced screening criteria, imaging options, and antithrombotic treatment for patients with blunt cerebrovascular injuries, with a focus on reducing the occurrence of ischemic stroke.
You arrive for your shift in the ED on a busy Friday night. Your first patient is a 29-year-old man who was the restrained driver in a motor vehicle crash in which he ran off the road at a high speed. He was intubated on the scene for airway protection. On examination, he has a GCS score of 6T, a large scalp laceration, symmetric pupils, and he withdraws all extremities from painful stimulation. His cardiac, pulmonary, and abdominal examinations are without significant findings, and his extremities have scattered abrasions. His initial trauma imaging includes a portable chest x-ray, a noncontrast CT of the head and cervical spine, and a CT of the abdomen/pelvis with contrast. The head CT showed a diffuse axonal injury and a temporal bone fracture. The remainder of the imaging showed no significant traumatic injuries. What else should be done at this point? What are his biggest risks right now? Is the temporal bone fracture concerning?
As you are pondering these questions, your next patient arrives. He is a healthy 42-year-old man who came to the ED due to neck pain. He was involved in a low-speed rear-end motor vehicle crash 2 days prior and felt fine, but today he developed severe pain in the left side of his neck that radiates to his left jaw. On examination, he has diffuse paraspinal tenderness that you presume to be muscle spasm, no apparent jaw abnormalities that would cause his pain, and his neurologic examination is negative. You obtain a CT of the head and cervical spine without contrast, which are both read as negative. You think there is only musculoskeletal involvement, but you keep wondering about the jaw pain. What else could this be? You give him some pain medications and decide to check on him later.
After leaving that patient’s room, you are called to the bedside of another patient just brought in by EMS. She is a 54-year-old woman with acute onset of vertigo and nausea/vomiting that started while she was at dinner with her family, 30 minutes prior to presentation. In the history, you note that she is otherwise healthy and takes no medications. She does experience chronic neck discomfort, for which she sees a chiropractor routinely, but she has never experienced symptoms like this. On examination, she has left-sided ataxia and nystagmus to left lateral gaze. You send her for a stat head CT without contrast and order stat labs. You think that she might be having a stroke, so you consult neurology for emergent evaluation. You have heard about the possibility of neck manipulation and dissection, but you wonder whether she is a candidate for any treatment.
Although a cervical artery dissection is rarely seen in the emergency department (ED), it can have devastating consequences if it is not recognized. Cervical artery dissections can occur spontaneously or due to a traumatic event, even with trivial or forgotten trauma. The incidence of spontaneous dissection is approximately 2 to 3 in 100,000 people per year, with carotid artery dissections more common than vertebral artery dissections.1 The incidence of traumatic cerebrovascular dissections is much higher, at approximately 1% of all adult blunt trauma admissions,2-4 and traumatic dissection causes up to 20% of strokes in patients aged < 45 years.5-10
Given the subtlety of symptoms in many patients, the condition is often not diagnosed until irreversible neurological injury has occurred. Symptoms may be delayed, and they may be similar to general symptoms, such as headache, neck pain, and dizziness, that are often seen in patients presenting to the ED. In the obtunded trauma patient, signs or symptoms of dissection may not be readily apparent, and the diagnosis will rely solely on advanced screening criteria. Unfortunately, 67% of these patients develop ischemia as a result of the untreated dissection, many within the first 24 hours.
Early treatment with an antithrombotic agent has been shown to be beneficial in the prevention of stroke due to dissection; however, the specific agent to use is not standardized. One randomized controlled trial attempted to determine superiority of antiplatelet agents versus anticoagulants, but the results were inconclusive.11 Therefore, the appropriate treatment is left to the judgment of the clinician and must be tailored to each patient based on comorbidities, risk for stroke, and contraindications to therapy.
This Emergency Medicine Practice: Trauma EXTRA supplement will review the mechanism of injury of cervical artery dissections, identify common presenting signs or symptoms and factors that place trauma patients at high risk, and discuss current diagnostic criteria and treatment options so that emergency clinicians can make a determination on the best treatment for each patient.
A literature search was performed using PubMed and the Cochrane Library with the search terms carotid artery dissection, vertebral artery dissection, cervical artery dissection, blunt cerebral vascular injury, dissecting intracranial aneurysm, intracranial dissection, and stroke dissection. The search was limited to human studies in the English language from 2001 to the present. The search yielded more than 1700 articles that were reviewed for appropriateness. Only clinically relevant, peer-reviewed journal articles were included.
The Cochrane Database of Systematic Reviews search yielded only 1 relevant article involving antithrombotic drugs for carotid artery dissection.12 One randomized controlled trial was found addressing medical, surgical, or endovascular treatment.11 Due to the low incidence of cervical artery dissections, there is a paucity of trials, and most of the data are from cohort and case-control studies in which patients with dissection were compared to patients without dissection with regard to symptoms, risk factors, imaging, treatment, and outcomes.
There are many guidelines related to the treatment of headache or stroke that mention cervical artery dissection, but there are no guidelines regarding the workup and treatment specifically focused on this condition. Organizations with related guidelines include the American Heart Association, American Stroke Association, American College of Radiology, and the Eastern Association for the Surgery of Trauma, among others. (See Table 1.) There are currently no clinical policies on the diagnosis or treatment of spontaneous or traumatic cervical artery dissections from the American College of Emergency Physicians.
1. “This patient has a left temporal headache that radiates into his left ear. His examination is benign, except his pupil is smaller on that side. I did a noncontrast head CT and it’s negative. The headache is probably just due to a hard game of basketball yesterday. I’m going to give him some IV ketorolac and send him out.”
Dissections can occur spontaneously or as a result of minor trauma, even from a rough basketball game. Failure to consider cervical artery dissection may result in a missed diagnosis. Headaches in carotid artery dissections can be nonspecific, but are mostly located in the frontal or temporal regions; radiation to the ear is also characteristic. His examination is also concerning for a partial Horner syndrome, which is also suspicious for carotid artery dissection and warrants further vascular imaging.
6. “I really thought that patient with the headache, anterolateral neck pain, and partial Horner syndrome had a carotid dissection, but the CTA was read as negative, so I guess I was wrong. I’ll just treat her pain and send her home.”
CTA is an excellent screening tool, but it is not 100% sensitive and can miss small intimal flaps, intramural hematomas, or slight fusiform dilatation of the vessel. In patients for whom there is a high suspicion of dissection and a negative or equivocal CTA or MRA, further imaging with MRI or digital subtraction angiography is indicated.
9. “The CTA showed a vertebral artery dissection in a patient who came to the ED after a roller coaster ride, so I consulted the neurology service for admission. Her neurologic examination was normal, so I’m going to wait to treat her and see what neurology recommends.”
An antithrombotic agent for stroke prevention can be started in the ED to avoid treatment delays. Studies have not shown superiority of one agent over another, so the choice of aspirin or heparin depends on patient factors. For uncomplicated dissections, antiplatelet agents are sufficient, and heparin is preferred in patients with an acute thrombus or high risk for thromboembolic events, if no contraindications exist.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, random-ized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study is included in bold type following the ref-erence, where available. In addition, the most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.
Rhonda Cadena, MD
Kaushal Shah, MD, FACEP
December 15, 2020
December 15, 2023
4 AMA PRA Category 1 Credits.™ Specialty CME Credits: Included as part of the 4 credits, this CME activity is eligible for 4 Stroke CME credits, subject to your state and institutional approval.
Date of Original Release: December 15, 2020. Date of most recent review: December 1, 2020. Termination date: December 15, 2023.
Accreditation: EB Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. This activity has been planned and implemented in accordance with the accreditation requirements and policies of the ACCME.
Credit Designation: EB Medicine designates this enduring material for a maximum of 4 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Specialty CME: Included as part of the 4 credits, this CME activity is eligible for 4 Stroke CME credits, subject to your state and institutional requirements.
Needs Assessment: The need for this educational activity was determined by a survey of medical staff, including the editorial board of this publication; review of morbidity and mortality data from the CDC, AHA, NCHS, and ACEP; and evaluation of prior activities for emergency physicians.
Target Audience: This enduring material is designed for emergency medicine physicians, physician assistants, nurse practitioners, and residents.
Goals: Upon completion of this activity, you should be able to: (1) demonstrate medical decision-making based on the strongest clinical evidence; (2) cost-effectively diagnose and treat the most critical presentations; and (3) describe the most common medicolegal pitfalls for each topic covered.
CME Objectives: Upon completion of this activity, you should be able to: (1) list the risk factors for blunt cerebrovascular injury; (2) identify factors in the history and physical examination that can be indicative of a dissection; (3) perform appropriate emergency department workup for diagnosis of carotid and vertebral artery dissections; and (4) initiate appropriate interventions to prevent stroke and to treat acute ischemic strokes due to blunt cerebrovascular injury.
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