Cervical Arterial Dissections and Association With Cervical Manipulative Therapy

A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

Patients should be warned before chiropractic manipulation of the neck that the technique has been linked to cervical dissection, which can cause stroke, the American Heart Association warned.
A scientific statement from the organization in the October issue of Stroke cautioned about the low level of evidence for a connection.
“Although the incidence of cervical dissection in cervical manipulative therapy patients is probably low, and causality difficult to prove, practitioners should both strongly consider the possibility of cervical dissection and inform patients of the statistical association between cervical dissection and cervical manipulative therapy, prior to performing manipulation of the cervical spine,” it said.
Most population-controlled studies have suggested an association, but reverse causation was possible, writing chair José Biller, MD, of Loyola University Chicago, and colleagues noted.
Part of the concern is that “patients with vertebral artery dissection commonly present with neck pain, which may not be diagnosed prior to any cervical manipulative therapy,” they wrote.
“Because patients with vertebral artery dissection commonly present with neck pain, it is possible that they seek therapy for this symptom from providers, including cervical manipulative therapy practitioners, and that the vertebral artery dissection occurs spontaneously, implying that the association … is not causal.
It is also plausible that cervical manipulative therapy could exacerbate the symptoms or the vertebral artery dissection and possibly increase the risk of stroke.”
Case reports and other clinical reports suggest that the mechanical forces of the quick or slow thrust often used by healthcare providers such as physical therapists, chiropractors or osteopaths may play a role in the development of cervical dissections, although the current biomechanical evidence is insufficient to establish any causal claim, the statement noted.
Patients with neck pain or headache with focal neurological symptoms after any minor trauma, including cervical manipulative therapy, should get immediate medical evaluation for possible stroke from cervical dissection, it recommended.
Exerpts from Paper:

Purpose—Cervical artery dissections (CDs) are among the most common causes of stroke in young and middle-aged adults. The aim of this scientific statement is to review the current state of evidence on the diagnosis and management of CDs and their statistical association with cervical manipulative therapy (CMT). In some forms of CMT, a high or low amplitude thrust is applied to the cervical spine by a healthcare professional.

Methods—Members of the writing group were appointed by the American Heart Association Stroke Council’s Scientific Statements Oversight Committee and the American Heart Association’s Manuscript Oversight Committee. Members were assigned topics relevant to their areas of expertise and reviewed appropriate literature, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge.

Results—Patients with CD may present with unilateral headaches, posterior cervical pain, or cerebral or retinal ischemia (transient ischemic or strokes) attributable mainly to artery–artery embolism, CD cranial nerve palsies, oculosympathetic palsy, or pulsatile tinnitus. Diagnosis of CD depends on a thorough history, physical examination, and targeted ancillary investigations. Although the role of trivial trauma is debatable, mechanical forces can lead to intimal injuries of the vertebral arteries and internal carotid arteries and result in CD. Disability levels vary among CD patients with many having good outcomes, but serious neurological sequelae can occur. No evidence-based guidelines are currently available to endorse best management strategies for CDs. Antiplatelet and anticoagulant treatments are both used for prevention of local thrombus and secondary embolism. Case-control and other articles have suggested an epidemiologic association between CD, particularly vertebral artery dissection, and CMT. It is unclear whether this is due to lack of recognition of preexisting CD in these patients or due to trauma caused by CMT. Ultrasonography, computed tomographic angiography, and magnetic resonance imaging with magnetic resonance angiography are useful in the diagnosis of CD. Follow-up neuroimaging is preferentially done with noninvasive modalities, but we suggest that no single test should be seen as the gold standard.

Conclusions—CD is an important cause of ischemic stroke in young and middle-aged patients. CD is most prevalent in the upper cervical spine and can involve the internal carotid artery or vertebral artery. Although current biomechanical evidence is insufficient to establish the claim that CMT causes CD, clinical reports suggest that mechanical forces play a role in a considerable number of CDs and most population controlled studies have found an association between CMT and VAD stroke in young patients. Although the incidence of CMT-associated CD in patients who have previously received CMT is not well established, and probably low, practitioners should strongly consider the possibility of CD as a presenting symptom, and patients should be informed of the statistical association between CD and CMT prior to undergoing manipulation of the cervical spine.