Extracranial vertebral artery rupture likely secondary to “cupping therapy” superimposed on spontaneous dissection

To the editor

Cupping, a treatment method in traditional Oriental medicine, has traditionally been performed with a small round cup made from thick glass with a rolled rim to maintain air-tight contact with the skin to preserve a vacuum.

We reported an extremely rare case of spontaneous extracranial vertebral artery dissection (VAD) presenting with posterior neck hematoma, which had been aggravated after a cupping therapy.¹

In our paper, we did not argue that spinal manipulative therapy, such as chiropractic treatment, directly causes VAD. We accepted that with undiagnosed VAD, traditional Oriental remedies—like the cupping treatment—may reduce pain and reduce aggravation of symptoms. In our case, we presumed that the patient’s neck pain began after spontaneous extracranial VAD, and the cupping therapy caused the vertebral artery (VA) to rupture, causing posterior neck hematoma with pseudoaneurysm. Because normal blood vessels are able to withstand high pressure, it is difficult to assume that the cupping treatment alone caused direct vessel rupture and neck hematoma. The tensile radial stresses generated by the cupping treatment potentially facilitated posterior neck hematoma formation with VA rupture in the presence of VAD.²

We are very surprised that the refuters misunderstood the subject of this paper. The objective of this case report was to show that early diagnosis of VAD could prevent symptom aggravation and permanent neurologic deficit; it was not to explain the cause of VAD.

They raised issues about the case reported by Blunt and Lee.³ We mentioned this to explain the possible mechanisms by which the cupping treatment can cause a stroke.³ The reviewers rebutted this by saying that the patient Blunt and Lee reported on had cupping treatment, but after seven days did not present with artery dissections on medical examination. The seven-day interval between the onset of the neck pain and subsequent examination is plenty of time for other various reasons to trigger a stroke. Cupping treatment may not be the only logical explanation.

Blunt and Lee described a patient who had received the cupping treatment on the neck and developed a hemorrhagic stroke 14 hours later.

In many cases, most patients had a stroke within 24 hours after the dissection. However, some stroke cases occurred several weeks after the onset of neck pain. There have been two autopsied cases of fatal VAD following motor vehicle accidents, showing the occurrence of a stroke seven weeks and two months after the accident, respectively.^4,5

We discussed the Blunt and Lee theory to provide four possible mechanisms by which the cupping treatment can lead to a stroke.

Moreover, the reviewers also said that we relied on many references from the 1980s (i.e. more than 35 years old) and that they have all been only case reports. We recognize that we relied on some cases that were more than 35 years old. However, the first recorded case of cerebellar and spinal cord injuries after chiropractic neck manipulation was in 1947, more than 60 years ago.⁶ Since then, there have been many publications and case reports on this topic, continuing even recently.^7,8

They asserted that several articles dispelled the theory of cervical spinal manipulation as a cause of VAD.^9,10

They also stated that much evidence suggests that neck pain and headaches are the reason for people seeking care, but the VAD had commenced prior to treatment.^10–12 Moreover, ascribing the care as the cause of the dissection is a case of protopathic bias.^13,14

Until now, there have been many debates between neurologists and chiropractors on the relationship between VAD and cervical manipulation therapy (CMT).^14–17

Because of the very rare incidence of VAD, the case-control studies are perhaps the best study design to date in determining whether CMT causes VAD.¹⁸

There have been six reported case-control studies of cervical artery dissection (CAD) that have evaluated the association between CMT and VAD.^{11,16,17,19–21}

Even though two of these case-control studies were very small cases, Thomas et al. reported that mild mechanical trauma to the head and neck was significantly associated with craniocervical arterial dissection.^17,19

There are four larger case-control studies that found an association between CMT and vertebrobasilar artery territory stroke in young patients,^11,16,20,21 and two of the four studies specifically evaluated chiropractic patients.^11,16

Rothwell and colleagues reviewed a total of 582 patients under 45 years old with VBA territory stroke, and they determined that young patients (age <45 years) with VBA territory stroke were five times more likely than the controls to have visited a chiropractor within one week of the event.¹⁶

Smith and associates used a case-control study design to review patients (age <45 years) with CAD, and the results showed a six-fold increase in VAD patients and stroke/transient ischemic attack (TIA), even after adjustment for neck pain before the stroke/TIA in the multivariate analysis; however, they showed no significant increase in cervical carotid artery dissection.²⁰

Cassidy et al. analyzed a total of 818 cases of VA territory distribution ischemic stroke. They evaluated the association between VA territory stroke and chiropractic visits, as well as seeing a primary care physician. For those under 45 years of age, they found an association between chiropractic visits and VA strokes. However, the risk was similar to the risk of VA stroke after seeing a primary care physician. This led the authors to conclude that chiropractic care does not appear to pose an excess risk of VA stroke, suggesting that headache or neck pain from VAD causes people to seek care from either chiropractic or medical physicians.¹¹

Other previous case-control studies^16,19,20 did not analyze the possible association with the evaluation by primary care physicians, leading to possible protopathic bias.¹³ The case selection in both the Rothwell et al.¹⁶ and Cassidy et al.¹¹ studies included patients with stroke in an anatomic distribution of posterior circulation, not with a given pathology of CAD.

In a report from the Cervical Artery Dissections and Ischemic Stroke Patients (CADISP) Study Group, prior cervical trauma was found in 40.5% of all CAD cases, which was significantly greater compared with the other stroke case group. The authors stated that their “findings suggest a clear association between CAD and CMT” and proposed the term, mechanical trigger event, as a more appropriate way to describe the variety of mechanical events reported in the association with CAD.²¹

In summary, a few case-control studies suggest the association between CMT and CAD. In the absence of prospective cohort or randomized studies, the best currently available evidence suggests that CAD, especially VAD, may be of a low incidence but could be a serious complication of CMT.

Although these studies suggest an association, it is very difficult to determine the precise causation because patients with VAD commonly present with neck pain, which may not be diagnosed prior to any CMT. A CMT practitioner argued that based on much current evidence, it appears that there is no strong foundation for a causal relationship between CMT and VADs, and the most plausible explanation for the association between CMT and VADs is that individuals who are experiencing a VAD seek care from a chiropractic physician or other manual practitioner to relieve the neck pain and headache that result from the dissection.²²

There have been some case studies that report young women visiting a chiropractic clinic with neck pain without receiving treatment on the initial visit. The chiropractors in these cases most likely suspected the possibility of VAD and no manipulation was performed. The patients were informed regarding the possibility of a CAD and were recommended to go to the emergency department for immediate evaluation. Magnetic resonance angiography (MRA) of the neck was obtained, which revealed an acute VAD with early thrombus formation.

These cases illustrate the importance for all health care providers who see patients with neck pain and headache to be attentive to the symptomatic presentation of possible VAD in progress.^23,24

Recognition and rapid response by chiropractic physicians can provide the optimum outcome for these kinds of patients.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Funding

The authors received no financial support for the research, authorship and/or publication of this article.