Focus On: Headache and Neck Pain - When to Suspect Cervical Artery Dissection

By Alicia Peterson, M.D., and Amer Aldeen, M.D.

Contributors 
Dr. Peterson is a resident in the emergency department at Northwestern University’s Memorial Hospital. She completed her residency training in Internal Medicine in 2011. Dr. Aldeen is an assistant professor in the Department of Emergency Medicine at Northwestern University’s Feinberg School of Medicine and an attending physician in the emergency department at Memorial Hospital. Dr. Robert Solomon is Medical Editor of ACEP NEWS and editor of the Focus On series, core faculty in the emergency medicine residency at Allegheny General Hospital, Pittsburgh, and Assistant Professor in the Department of Emergency Medicine at Temple University School of Medicine, Philadelphia.

Disclosures
In accordance with the Accreditation Council for Continuing Medical Education (ACCME) Standards and American College of Emergency Physicians policy, all individuals in control of content must disclose to the program audience the existence of significant financial interests in or relationships with manufacturers of commercial products that might have a direct interest in the subject matter.

Dr. Peterson, Dr. Aldeen, and Dr. Solomon have disclosed that they have no significant relationships with or financial interests in any commercial companies that pertain to this article.

This activity has been planned and implemented in accordance with the Essential Areas and Policies of the Accreditation Council for Continuing Medical Education (ACCME). The American College of Emergency Physicians is accredited by the ACCME to provide continuing medical education for physicians.

The American College of Emergency Physicians designates this enduring material for a maximum of 1 AMA PRA Category 1 CreditTM. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

"Focus On: Headache and Neck Pain - When to Suspect Cervical Artery Dissection" is approved by the American College of Emergency Physicians for one ACEP Category I credit.

Disclaimer
ACEP makes every effort to ensure that contributors to College-sponsored programs are knowledgeable authorities in their fields. Participants are nevertheless advised that the statements and opinions expressed in this article are provided as guidelines and should not be construed as College policy. The material contained herein is not intended to establish policy, procedure, or a standard of care. The views expressed in this article are those of the contributors and not necessarily the opinion or recommendation of ACEP. The College disclaims any liability or responsibility for the consequences of any actions taken in reliance on those statements or opinions.

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This article was published online March 1, 2013. The credit for this CME activity expires February 28, 2016.

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Learning Objectives
After reading this Web-based article, the physician should be able to:
  • Review the pathophysiology of cervical artery dissection.
  • Recognize the clinical presentation of carotid and vertebral artery dissection.
  • Understand when patients with headache and neck pain need imaging.
  • Discuss the benefits and limitations of CT and MR angiography.
  • Understand the ED management of cervical artery dissection.

Introduction
Headache and neck pain are extremely common chief complaints in the emergency department. One study found that “symptoms involving head and neck” was the sixth-most common ED diagnosis, seen in 2.2% of ED visits.1 The estimated 1-year incidence of neck pain alone can be more than 20%.2 The majority of patients with headache and neck pain do not have a life-threatening problem. The challenge for emergency physician is to recognize signs of cervical artery dissection in patients presenting with head and neck pain. Early identification and treatment of dissection reduces the risk of stroke and death.

While the overall incidence of cervical artery dissection is very low, it is a common etiology of stroke in adults younger than 50, causing up to 10% of the cases.3 Incidence has increased in the past decade, likely due to improved imaging modalities. The incidence of spontaneous cervical arterial dissection is 3-5 per 100,000.4 The incidence of traumatic cervical artery dissection is 1 per 1000.4 Cervical arterial dissections most commonly occur in the carotid arteries, followed by the vertebral arteries.

Pathophysiology
Dissection is caused by an intimal tear leading to bleeding into the vascular wall, which can lead to vessel occlusion, thrombus with subsequent distal emboli, aneurysm formation, and subarachnoid hemorrhage. Arteries are most prone to dissection when they are stretched over bony prominences. Carotid artery dissection most commonly occurs 2 cm above the bifurcation of the common carotid artery, where the extra-cranial portion of the internal carotid artery travels over C2-3. Vertebral artery dissection most commonly occurs at C1-2, due to compression of the vessel against the C2 cervical foramina during head rotation, and at C5-6, where the artery enters the transverse foramina.4 Compression of the vessel can cause blood to pool and clot in the vessel, then subsequently embolize to distal vessels, resulting in ischemic stroke.

Clinical Presentation
Early presentation of cervical artery dissection can be very subtle and overlaps with more common causes of headache and neck pain like tension headache or musculoskeletal neck pain. Up to 80% of cervical artery dissections are preceded by trauma to the head or neck.3 Dissection has been associated with chiropractic manipulation, weight lifting, roller coasters, and wrestling.5,4 Blunt and penetrating neck trauma may also cause cervical artery dissection. However, the inciting incident may be so benign that the patient may not even remember it. Dissection has been reported following activities as innocuous as shaving, vomiting, yoga, massage, nose blowing, and swimming.3 Symptoms usually start immediately after the traumatic event, although some patients may not experience any symptoms for a week. The average time from traumatic event to onset of symptoms is 2-3 days.6 What further complicates the diagnosis is that the typical ED evaluation of a new headache – non-contrast computed tomography (CT) scan of the head and possible lumbar puncture – will miss most cases of dissection. Ischemic stroke occurs in up to 86% of all dissections and is the presenting symptom in 72%.6 The mean age for carotid artery dissection is 47, and that for vertebral artery dissection is 40.7.7 About 5% of patients have underlying vascular abnormalities such as fibromuscular dysplasia, Marfan’s syndrome, or osteogenesis imperfecta.4

Carotid artery dissection
While affecting only 8% of patients, the triad of headache, ipsilateral oculosympathetic paresis, and contralateral stroke symptoms is very concerning for carotid artery dissection.4 Oculosympathetic paresis (also referred to as a partial Horner syndrome) is defined as ptosis and miosis without anhidrosis. This phenomenon is caused by ischemia or compression of sympathetic fibers that run from the internal carotid artery plexus. Facial sweating is preserved because the external carotid plexus is not affected. Almost a third of patients have a partial Horner syndrome.5

Headache is present in up to 75% of patients.7 The headache of carotid artery dissection may be gradual onset or thunderclap, and it may resemble prior migraines. The quality of the headache is neither sensitive nor specific for carotid artery dissection. Up to 50% of patients have a history of prior migraines or other similar headache.3 Some patients complain of facial or scalp pain rather than headache. Neck pain is typically located over the anterolateral aspect of the neck, up to the jaw and even the ear. Dysgeusia (abnormal taste) is only seen in up to 7% of patients, but when present, is very specific for dissection.4 Neither bruits nor pulsatile tinnitus is sensitive or specific for dissection. Signs of stroke develop in most patients. The most common distribution for cerebral ischemia is the middle cerebral and anterior cerebral arteries. Cranial nerve palsies are present in about 10%.4

Vertebral Artery Dissection
Patients with vertebral artery dissection present with unilateral headache with signs and symptoms consistent with lateral medulla ischemia. Lateral medulla ischemia, also known as Wallenberg syndrome, is characterized by dysmetria, ataxia, ipsilateral hemiplegia, and contralateral loss of pain and temperature sensation.3 Patients may complain of double vision, dizziness, and vomiting, often referred to as “cerebellar signs.” It is important to distinguish between “blurry vision” and “double vision.” Many patients in the emergency department will report blurry vision on review of symptoms, which is likely just presbyopia. Specifically ask about double vision or visual field cuts. The presence of either of these should raise the concern for neurologic deficits.

Most, but not all, patients with vertebral artery dissection have a headache.7 Headache is severe, unilateral, and often posterior-occipital. Whereas patients with carotid artery dissection may present with a wide variety of types of headaches, the quality of the headache in vertebral artery dissection is much more consistently unilateral and severe.7 Almost half of patients have neck pain of gradual onset. Less commonly, patients will present with isolated neck pain and no headache. On exam, patients may have neck tenderness with palpation. Do not be falsely reassured by reproducible neck pain when it comes to evaluation of vertebral artery dissection.

When compared to carotid artery dissection, vertebral artery dissection is more likely to affect younger patients. It is more common in women and in patients with chronic migraines.

Diagnostic studies
Once you suspect cervical artery dissection, choosing the appropriate imaging modality is key. The usual approach to a new headache in the emergency department is a non-contrast head CT and possible lumbar puncture. Unfortunately this may miss uncomplicated cervical artery dissection, leading to delays in the diagnosis and subsequent stroke or death. Historically, cerebral angiography has been the “gold standard” for diagnosis of dissection. Angiographic findings suggestive of dissection include intimal flaps, pseudoaneurysm, and luminal stenosis or occlusion.3 However, cerebral angiography is less commonly used today due to the invasive nature and the risks of the procedure. Conventional angiography has been replaced in the ED by the faster and more readily available magnetic resonance angiography (MRA) and computed tomography angiography (CTA). In some populations, the introduction of MR and CT has increased the rate of diagnosis of cervical artery dissection up to 10-fold.8 Ultrasound has been studied in cervical artery dissection, but it is less sensitive than CTA or MRA.

The largest series comparing MRA to traditional angiography found a sensitivity of 83% and a specificity of 99% for carotid artery dissection and a sensitivity of 20% and a specificity of 100% for vertebral artery dissection.9 Accuracy of CTA has improved over the past decade with the use of multi-detector CT scanners, with a sensitivity of 90% and a specificity of 100%.10

The general consensus among experts is that CTA is the better screening test because it is faster, cheaper, and shows excellent visualization of large vessels, including the carotids and vertebrals. If CTA shows dissection, MRA is an appropriate follow-up test because it allows for better visualization of small vessels and will also show cerebral ischemia if present. A reasonable initial approach to a patient with a suspected cervical artery dissection would be to obtain a non-contrast head CT, and if negative, proceed with a CTA head and neck. If dissection is identified, obtain MR brain and MRA head and neck for further evaluation.

Emergency Department Management
The management of patients diagnosed with cervical artery dissection begins with evaluation of candidacy for fibrinolytic therapy with tissue plasminogen activator (tPA). This should be done in consultation with a neurologist. Dissection patients were included in the National Institute of Neurological Disorders and Stroke IV tPA trial (NINDS).11 No adverse bleeding events were seen. There was slightly less neurologic improvement seen in the dissection group compared with the non-dissection group (but still greater than the control group). Most patients with dissection present much later than the 3-hour symptom window for tPA, and the dissection must be limited to extra-cranial vessels in order for tPA to be considered. Emerging research suggests that endovascular stenting may also improve neurologic outcomes in dissection patients in the acute phase of stroke.12 Admit all patients with cervical artery dissection to a telemetry-monitored hospital bed, as even patients who are relatively asymptomatic from their dissection may progress to ischemic stroke with devastating neurologic deficits.

The long-term treatment of cervical artery dissections is anti-platelet therapy with aspirin 325 mg daily or anticoagulation with warfarin with a goal INR 2-3 for 3-6 months. Both have been shown to reduce the progression to ischemic stroke. No study has ever shown a significant advantage of anticoagulation over anti-platelet therapy.13 In one study, treatment of traumatic dissection with anti-platelet or anticoagulant therapy reduced the incidence of stroke from 64% to 6.8% for carotid dissection and from 54% to 2.6% for vertebral dissection.14 If the patient is not a candidate for tPA, then a heparin drip should be started in the ED. Once the patient is admitted, the neurologist can then determine whether the patient will ultimately be on aspirin or warfarin. Blood pressure goals in the acute setting have not been clearly established, but pilot studies recommend permissive hypertension of the systolic blood pressure up to 200 mm Hg.4

Conclusion
Headache and neck pain are common chief complaints in the emergency department. While they are usually of benign etiology, they might represent early symptoms of a cervical arterial dissection. Dissection needs to be considered in any young patient who presents with neurologic symptoms or signs. Important clinical clues that suggest dissection include any focal neurologic deficit in the setting of headache, facial pain, or neck pain. A partial Horner syndrome should heighten your suspicion. In every case, emergency physicians should question patients about any preceding trauma, and be sure to tell them it doesn’t matter how trivial that trauma might seem. Typical screening tests like non-contrast CT and lumbar puncture may miss an uncomplicated dissection. When dissection is suspected, CTA neck is the next appropriate test. Making the diagnosis is critical, as progression to stroke can be reduced by appropriate therapy. Long term anti-platelet or anticoagulation therapy is recommended.

References

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  2. Hoy DG, Protani M, De R, et al. The epidemiology of neck pain. Best practice and research clinical rheumatology. 2010 Dec;24(6):783-791.
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  4. Shea K, Stahmer S. Carotid and vertebral arterial dissections in the emergency department. Emerg Med Pract. 2012 Apr;14(4):1-23.
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  6. Biousse V, D'Anglejan-Chatillon J, Touboul PJ, et al. Time course of symptoms in extracranial carotid artery dissections. A series of 80 patients. Stroke. 1995;26(2):235-239.
  7. Silbert PL, Mokri B, Schievink WI. Headache and neck pain in spontaneous internal carotid and vertebral artery dissections. Neurology. 1995;45(8):1517-1522.
  8. Provenzale JM, Sarikaya B. Comparison of test performance characteristics of MRI, MR angiography, and CT angiography in the diagnosis of carotid and vertebral artery dissection: a review of the medical literature. Am J Roentgenol. 2009;193(4):1167-1174.
  9. Levy C, Laissy JP, Raveau V, et al. Carotid and vertebral artery dissections: three-dimensional time-of-flight MR angiography and MR imaging versus conventional angiography. Radiology 1994;190:97-103.
  10. Munera F, Soto JA, Palacio D, et al. Diagnosis of arterial injuries caused by penetrating trauma to the neck: comparison of helical CT angiography and conventional angiography. Radiology. 2000;216(2):356-362.
  11. Tissue plasminogen activator for acute ischemic stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. N Engl J Med. 1995;333(24):1581-1587.
  12. Menon R, Kerry S, Norris JW, et al. Treatment of cervical artery dissection: a systematic review and meta-analysis. J Neurol Neurosurg Psychiatry. Oct 2008;79(10):1122-1127.
  13. Miller PR, Fabian TC, Croce MA, et al. Prospective screening for blunt cerebrovascular injuries: analysis of diagnostic modalities and outcomes. Ann Surg. 2002;236(3):386-393. 
  14. Georgiadis D, Arnold M, von Buedingen HC, et al. Aspirin vs anticoagulation in carotid artery dissection: a study of 298 patients. Neurology. 2009;72(21):1810-1815. 
  15. Touze E, Gauvrit JY, Moulin T, et al. Risk of stroke and recurrent dissection after a cervical artery dissection: a multicenter study. Neurology. 2003;61(10):1347-1351.
  16. Savitz SI, and Caplan LR. Vertebrobasilar Disease. N Engl J Med. 2005;352(25):2618-2626.




 

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