Cervical artery dissection is a tear in the wall of one of the major arteries running through the neck to the brain, either the internal carotid artery or the vertebral artery. A blood clot (hematoma) forms within the vessel wall itself, which can narrow or block blood flow and send clot fragments toward the brain, causing stroke. It is the leading cause of stroke in adults younger than 45, yet most people have never heard of it. The condition sits at a peculiar intersection of bad luck, subtle genetic vulnerability, and sometimes surprisingly mundane physical triggers, and the science behind who gets it and why is still catching up.
What Happens Inside the Artery
The arteries supplying the brain have multiple layers. In a dissection, blood forces its way between the inner lining and the muscular middle layer of the vessel wall, creating a pocket of trapped blood. That pocket bulges inward, narrowing the channel where blood normally flows, or it can balloon outward, forming a pouch called a pseudoaneurysm. The hematoma itself often arises in connection with minor injuries, and an underlying weakness of the arterial wall, possibly only temporary, may act as a predisposing factor.1PubMed Central. The Clinical Features of Dissection of the Cervical Brain-Supplying Arteries
The most dangerous consequence is stroke, and the usual mechanism is not simple blockage at the dissection site. Instead, clot material forming on the torn vessel wall breaks off and travels upstream into the brain, a process called artery-to-artery embolism. Research using advanced imaging has confirmed that this embolic pattern is the most frequent cause of stroke in dissection patients.2PubMed. Mechanism of ischemic infarct in spontaneous cervical artery dissection This distinction matters for treatment because the goal is not just reopening the artery but preventing clot fragments from reaching the brain in the first place.
Recognizing the Symptoms
Cervical artery dissection does not always announce itself with dramatic stroke symptoms. Many patients experience warning signs for hours or even days before any neurological problems appear. The most common early complaint is headache or neck pain, often unlike anything the person has felt before. The pain tends to be one-sided, sharp, and persistent. It may start at the back of the head or deep in the neck and radiate forward.
A distinctive sign of carotid dissection is partial Horner’s syndrome: the pupil on the affected side becomes smaller, and the eyelid may droop slightly. A case report of a 44-year-old woman who presented with one-sided headache, neck pain, and unequal pupil sizes illustrates how this combination should raise suspicion for dissection.3PubMed Central. Partial Horner’s Syndrome as a Manifestation of Carotid Artery Dissection: A Case Report and Diagnostic Approach Pulsatile tinnitus, a rhythmic whooshing sound in one ear, is another clue, particularly with carotid dissection. These symptoms are easy to dismiss as a migraine or a stiff neck, which is partly why dissection is underdiagnosed.
Vertebral artery dissection tends to present differently. Neck pain is more prominent, and sudden, explosive “thunderclap” headache is more common compared to carotid dissection. Vertebral dissections also carry a higher rate of stroke at presentation and can occasionally cause bleeding around the brain (subarachnoid hemorrhage), something rare with carotid dissections.4PubMed. Differences and similarities between spontaneous dissections of the internal carotid artery and the vertebral artery
Carotid Versus Vertebral Dissection
Though both types fall under the umbrella of cervical artery dissection, they differ in who they affect, how they look on imaging, and what complications they tend to cause. A large multicenter study (the CADISP study) found that carotid dissection patients were older on average, more often male, and more likely to report a recent infection. Vertebral dissection patients, by contrast, more often reported minor neck trauma in the preceding weeks, were more likely to have dissections on both sides at once, and presented with cerebral ischemia more frequently.5PubMed. Differential features of carotid and vertebral artery dissections: the CADISP study
On imaging, carotid dissections tend to occur in the extracranial portion of the artery (the part in the neck), while vertebral dissections more often involve the intracranial segment (the part inside the skull).6PubMed Central. Predisposing factors and radiological features in patients with internal carotid artery dissection or vertebral artery dissection This anatomical difference has real clinical consequences: intracranial dissections are harder to reach with interventional treatments and carry different bleeding risks. The two types also differ in their visible signs on scans. Carotid dissections more frequently show an intimal flap (a visible strip of torn inner lining) and a double lumen, while vertebral dissections more often produce pseudoaneurysms.7PubMed Central. Predisposing factors and radiological features in patients with internal carotid artery dissection or vertebral artery dissection
What Triggers a Dissection
The American Heart Association describes cervical artery dissection as the result of interplay among risk factors, minor trauma, anatomic and congenital abnormalities, and genetic predisposition.8PubMed. Treatment and Outcomes of Cervical Artery Dissection in Adults: A Scientific Statement From the American Heart Association In practice, this means many patients have a combination of a vulnerable artery wall and a triggering event, though neither factor alone would be enough.
Roughly 40% of dissection patients report some kind of preceding physical trigger, and the vast majority of those triggers are classified as mild. A large study comparing dissection patients with stroke patients who did not have dissections and with healthy subjects found that mechanical trigger events were far more common in the dissection group. Because most of these triggers were so minor, the researchers suggested the term “mechanical trigger event” was more appropriate than “trauma.”9PubMed. Cervical artery dissection: trauma and other potential mechanical trigger events The list of reported triggers is almost comically wide-ranging: vigorous coughing or sneezing, yoga poses, roller coasters, painting a ceiling, turning the head sharply while driving, or even vomiting. None of these activities would be dangerous for someone with normal arteries, which underscores that it is the underlying vulnerability that matters most.
Recent infections have also emerged as a risk factor. One case-control study found that acute infection was present in about a third of dissection patients versus roughly one in seven controls. The link was even stronger in patients who had dissections in multiple arteries simultaneously.10PubMed. Infection and the risk of spontaneous cervical artery dissection: a case-control study A separate study found that flu-like illness was associated with a higher short-term risk of dissection, particularly within two weeks of the illness.11PubMed Central. Influenza-Like Illness is Associated with Increased Short-Term Risk of Cervical Artery Dissection The leading theory is that systemic inflammation temporarily weakens the arterial wall, making it more susceptible to tearing.
The Connective Tissue Question
One of the most active areas of research involves the arterial walls themselves. About half of patients with spontaneous cervical artery dissection show subtle connective tissue abnormalities when skin samples are examined under electron microscopy. These changes are too mild to produce the joint hypermobility, stretchy skin, or other obvious signs that characterize named genetic syndromes like Ehlers-Danlos syndrome. Yet the microscopic pattern resembles milder versions of what is seen in those disorders.12PubMed. Association of cervical artery dissection with connective tissue abnormalities in skin and arteries
Fewer than 5% of dissection patients meet the clinical criteria for a named heritable connective tissue disorder. A prospective evaluation of consecutive patients found that while heritable connective tissue disorders were common in this group, intensive laboratory workups usually could not identify the specific type of disorder.13PubMed. Heritable connective tissue disorders in cervical artery dissections: a prospective study In the arterial walls themselves, researchers have found pronounced elastic fiber fragmentation and degeneration of the middle layer, abnormalities previously documented only in patients with known genetic conditions like Marfan syndrome. This has led to the hypothesis that many spontaneous dissections represent a clinically silent connective tissue disorder with a “vascular phenotype,” meaning the arteries are affected but the rest of the body shows little or no sign.14PubMed. Association of cervical artery dissection with connective tissue abnormalities in skin and arteries
Genetic studies have found rare cases where patients carry large genetic copy-number variants covering genes associated with Ehlers-Danlos syndrome subtypes or familial aortic aneurysm syndromes.15PubMed Central. Multiple Arterial Dissections and Connective Tissue Abnormalities A multicenter prospective study tracking blood biomarkers found that dissection patients had persistently lower levels of circulating elastin and collagen type III compared to controls, even months after the acute event. Because these levels were not elevated during the acute phase, they are not useful for diagnosing a dissection in real time, but they do reinforce the idea of an underlying structural vulnerability in the connective tissue of these patients.
How It Is Diagnosed
Imaging is the cornerstone of diagnosis. The main options are CT angiography (CTA) and MRI with MR angiography (MRA). Both can identify the hallmark findings: narrowing of the artery, a crescent-shaped hematoma in the vessel wall, an intimal flap, or a pseudoaneurysm. A literature review comparing the two concluded that the test characteristics for MRI/MRA and CTA were relatively similar in diagnosing both carotid and vertebral artery dissection.16PubMed. 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
That said, each modality has strengths. CTA tends to pick up more intimal flaps, pseudoaneurysms, and severe narrowings, and it was the preferred diagnostic method for vertebral artery dissections in a head-to-head comparison.17PubMed Central. Comparison of multidetector CT angiography and MR imaging of cervical artery dissection MRI, on the other hand, can directly visualize the blood clot within the artery wall (the intramural hematoma), especially on fat-suppressed T1-weighted sequences, and in one study it caught pseudoaneurysms that CTA missed.18PubMed. CT versus MR Techniques in the Detection of Cervical Artery Dissection In emergency settings, CTA is often done first because it is faster and more widely available. MRI is frequently added for confirmation or to track healing over time.
Treatment and the Antiplatelet-Versus-Anticoagulation Debate
Once a dissection is diagnosed, the primary goal is preventing stroke or preventing a second stroke if one has already occurred. For most patients, this means blood-thinning medication. But which type? This has been one of the most debated questions in stroke neurology for years.
The CADISS trial, the largest randomized trial on this question, found that the risk of recurrent stroke at one year was low at about 2.5%, and there was no significant difference in stroke recurrence or vessel healing between patients assigned to antiplatelet drugs versus anticoagulants.19PubMed Central. Antiplatelet Therapy vs Anticoagulation Therapy in Cervical Artery Dissection: The Cervical Artery Dissection in Stroke Study (CADISS) Randomized Clinical Trial A later individual-patient-data meta-analysis that pooled data from randomized trials found a trend favoring anticoagulation for preventing stroke (roughly 0.5% of anticoagulation patients had a stroke versus about 4% on aspirin alone), but this came at the cost of more bleeding events, and the overall composite endpoint did not reach statistical significance.20JAMA Neurology. Antithrombotic Treatment for Cervical Artery Dissection: A Systematic Review and Individual Patient Data Meta-Analysis
A separate European trial (TREAT-CAD) tried to show that aspirin was “not worse than” a vitamin K antagonist (the traditional type of anticoagulant), but it failed that test. About 23% of aspirin patients versus 15% of anticoagulation patients reached the combined outcome, and the statistical bar for calling the two equivalent was not met.21The Lancet Neurology. Antiplatelet therapy versus anticoagulation in cervical artery dissection In practice, this leaves clinicians in a gray zone. Many use antiplatelet therapy as the default because of its simpler side-effect profile, but switch to anticoagulation when they see features suggesting a higher embolic risk, such as a free-floating clot or a severely narrowed artery.
Endovascular treatment with stents is reserved for cases that fail medical therapy or that involve hemodynamically significant narrowing or growing pseudoaneurysms. A small series using newer double-mesh stents reported no strokes or deaths during or after the procedure, with all treated arteries remaining open during follow-up of up to about three years.22PubMed Central. Endovascular management of carotid and vertebral artery dissections with new generation double-mesh stent and protection systems – single-center early and midterm results Still, stenting is the exception rather than the rule. Most dissections heal on their own with medication alone.
How Arteries Heal and What Recurrence Looks Like
The natural history of cervical artery dissection is more encouraging than many patients expect. More than three-quarters of cases present with narrowing or occlusion on imaging, but the vessel often recovers. Complete resolution of the abnormality has been reported in about 80% of cases, and most healing occurs within the first three to six months.23PubMed Central. Cervical Artery Dissections: Etiopathogenesis and Management Roughly one in five patients develops a pseudoaneurysm, but this turns out to be a fairly benign finding, with an extremely low rate of rupture or future stroke.24PubMed Central. Cervical Artery Dissections: Etiopathogenesis and Management A long-term follow-up study of conservatively managed patients found that about 91% reported complete symptom resolution, and imaging showed full anatomical healing in the majority who underwent repeat scans.25PubMed. Long-term outcome of cervical artery dissection
Recurrence, though understandably feared, is uncommon. A systematic review and meta-analysis found an overall recurrence rate of about 4%, with roughly 2% recurring within the first month and about 7% at one year in studies with longer follow-up.26PubMed Central. Recurrence of cervical artery dissection: A systematic review and meta-analysis A secondary analysis of a large registry found that among those who did have a recurrence, the estimated two-year recurrence rate was about 3.2%. Younger age, a history of migraine, and the presence of fibromuscular dysplasia (a condition where arteries develop abnormal cell growth in their walls) were all linked to higher recurrence risk. Interestingly, patients whose initial dissection had caused a stroke were less likely to have a recurrence, possibly because they received more aggressive treatment and monitoring.27PubMed. Recurrent Cervical Artery Dissection Prevalence and Predictors: A Secondary Analysis of the STOP-CAD Study Even when dissections do recur, they rarely cause stroke. In that same registry, only 5 of 88 recurrences were accompanied by ischemic events.28PubMed. Recurrent Cervical Artery Dissection Prevalence and Predictors: A Secondary Analysis of the STOP-CAD Study
The Chiropractic Controversy
Few topics in cervical artery dissection generate more heated debate than the possible link to chiropractic neck manipulation. The concern is intuitive: if rotational or extension forces on the neck can trigger a dissection, then high-velocity manipulation of the cervical spine could plausibly do the same. But the data are muddier than either side of the debate acknowledges.
A systematic review and meta-analysis found a small statistical association between chiropractic neck manipulation and cervical artery dissection but concluded there was no convincing evidence to support a causal link. The authors pointed out that the available studies were plagued by high risk of bias, and that the association could largely be explained by the fact that people with early, undiagnosed dissections often have neck pain, which is exactly the symptom that drives them to a chiropractor in the first place.29PubMed Central. Systematic Review and Meta-analysis of Chiropractic Care and Cervical Artery Dissection: No Evidence for Causation A more recent meta-analysis pooling data from multiple studies found no statistically significant risk within 30 days of spinal manipulation. One study within that analysis did find increased risk in younger patients within 14 days, but the same elevated risk appeared after visits to a primary care physician, suggesting that the common factor was neck pain prompting medical attention rather than the manipulation itself.30BMJ. Risk factors for cervical artery dissection: a systematic review with meta-analysis
The honest summary: a causal relationship has not been established, but it also has not been definitively ruled out. Cervical manipulation may be capable of triggering dissection in someone whose artery wall is already vulnerable, or it may be that the dissection was already underway before the patient walked through the door.31PubMed Central. The etiology of cervical artery dissection For patients with known connective tissue disorders or a history of dissection, most neurologists advise against high-velocity cervical manipulation as a precaution.
Pregnancy and Postpartum Risk
Pregnancy roughly doubles the risk of cervical artery dissection. A case-control study comparing women with dissection to matched controls found that pregnancy was about 2.5 times more common in the dissection group, with the heightened risk concentrated in the postpartum period, where the risk was roughly five and a half times higher than baseline.32PubMed Central. Association Between Pregnancy and Cervical Artery Dissection A separate propensity-matched cohort study confirmed the roughly twofold overall risk, though that study suggested most cases occurred during pregnancy itself rather than afterward.33Journal of Stroke and Cerebrovascular Diseases. Pregnancy and spontaneous cervical artery dissection: A propensity-matched retrospective cohort study The physiological explanation likely involves the hormonal and hemodynamic changes of pregnancy: blood volume increases, cardiac output rises, and connective tissue loosens under the influence of hormones like relaxin.
Despite the increased risk, the absolute numbers remain small. The incidence in pregnant and postpartum women was estimated at about 8 per 100,000 person-years, compared to about 4 per 100,000 in matched non-pregnant women.34Journal of Stroke and Cerebrovascular Diseases. Pregnancy and spontaneous cervical artery dissection: A propensity-matched retrospective cohort study A systematic review of reported pregnancy-related cases identified migraine, connective tissue disorders, preeclampsia, and prolonged second stage of labor as recurring risk factors. The prognosis was generally favorable, with about 78% of patients making a full clinical recovery.35PubMed. Systematic review of postpartum and pregnancy-related cervical artery dissection Treatment during pregnancy largely mirrors non-pregnant patients but avoids certain anticoagulants that cross the placenta.
Children and Adolescents
Cervical artery dissection is not exclusively an adult condition, though it is rarer in children. It accounts for roughly 5% to 25% of childhood strokes and occurs in an estimated 2.5 children per 100,000 per year. In children, the presentation is usually sudden neurological symptoms, either full stroke or a transient episode. Trauma, particularly head and neck injuries from sports or accidents, is a more prominent trigger in pediatric cases than in adults. Connective tissue disorders and male sex are also recognized risk factors in this age group.
Getting Back to Normal Life
One of the most common questions after a dissection is when and how to resume physical activity. Expert guidance suggests avoiding all sports for at least one month after the event, with the pause extended if the clinical picture or vessel imaging is not improving.36PubMed Central. Cervical Artery Dissection and Sports When returning to exercise, the recommended approach is to start with low-intensity endurance activities and increase gradually. The pace of return should be tailored to the individual, taking into account whether the dissection was associated with a specific sport or physical activity, whether there are neurological deficits, what the follow-up imaging shows, and whether there are signs of an underlying connective tissue abnormality.37PubMed Central. Cervical Artery Dissection and Sports
Activities that involve sudden neck rotation, heavy Valsalva straining (bearing down hard while holding your breath), or direct contact to the head and neck carry a theoretical risk and are generally discouraged for longer. There is no universal protocol, and recommendations vary between clinicians. Most patients are encouraged to stay active within comfortable limits, because the cardiovascular and psychological benefits of exercise are substantial, and the absolute risk of recurrence is low. The practical reality for most dissection survivors is that they return to a largely normal life within a few months, often with nothing more than follow-up imaging and a low-dose daily antiplatelet medication as reminders of what happened.