Attorneys will come across cases of stroke following cervical spine manipulation by a doctor of chiropractic (DC). The cases are often similar. The plaintiff went to see the defendant with neck pain and/or headache, and immediately after a neck manipulation, usually a matter of seconds, the plaintiff developed ischemic stroke symptoms, sometimes resulting in paralysis or death. This article will describe how to evaluate the standard of care for the case as the attorney for the plaintiff, and as the attorney for the defendant.
The traditional mechanism of causation in these cases is that cervical spine manipulation can tear (or dissect) the inner lining of an otherwise healthy artery in the neck and cause a stroke, immediately. However, this mechanism is not supported by the literature. The plaintiff that attempts to make this argument will find themselves buried by the defendant in an avalanche of studies that show no causal association between cervical spine manipulation and cervical artery dissection. Expert witnesses in chiropractic and neurology will also testify to no causal relationship between manipulation and dissection. In fact, in 2016 a group of neurologists from Penn State Medical Center published one of the most important studies in this area.
Even if there were studies which showed that cervical spine manipulation can cause dissection in a normal cervical artery, stroke would not occur immediately, due to the nature of arterial dissection and resultant blood clot formation. It takes time for a blood clot to form after dissection and then dislodge and block a smaller artery that supplies the brain, resulting in an embolic cervical artery ischemic stroke. It takes time for a blood clot to form and become so large that it blocks the artery, resulting in a thrombotic cervical artery ischemic stroke.
Breach of Standard of Care 1: Causation of Stroke
Even if there is no causal association between manipulation and dissection, there can be a causal relationship between manipulation and stroke. Although cervical spine manipulation is not shown to cause cervical artery dissection, the DC may breach the standard of care by performing cervical spine manipulation in the presence of a pre-existing cervical artery dissection.
In the presence of cervical artery dissection, cervical spine manipulation may exacerbate cervical artery dissection and result in immediate cervical artery stroke by two mechanisms: First, the cervical spine manipulation could worsen pre-existing arterial dissection damage, leading to positional occlusion of an already narrowed vertebral or internal carotid artery. Second, the cervical spine manipulation could dislodge a cervical artery blood clot. The dislodged blood clot may block a smaller artery that supplies the brain, causing an arterial stroke.
Therefore, if a DC performs cervical spine manipulation in the presence of a pre-existing cervical artery dissection which precipitates an immediate cervical artery stroke, the doctor has breached the standard of care and may be held liable for the occurrence of the stroke.
The attorney for the defendant should evaluate what the plaintiff is alleging carefully. If the plaintiff is alleging the defendant caused a cervical artery dissection as a result of manipulation, the plaintiff has no case. However, if the plaintiff is alleging the defendant caused a cervical artery stroke via manipulation performed in the presence of existing arterial dissection, then the attorney for the defendant will have more work to do.
The attorney for the defendant should evaluate the timeline of the case. If ischemic symptoms of stroke did not begin immediately following the manipulation, in a matter of seconds, then the manipulation and stroke may not be causally related. Any movement of the neck which stretches a cervical artery could damage the artery or free a blood clot and cause ischemic stroke. The plaintiff must show it was the motion of the manipulation which caused the stroke. If the plaintiff goes about moving their neck in the course of normal life for minutes, hours, days or weeks after the manipulation before the onset of ischemic stroke symptoms, a causal connection may not be possible to prove.
Breach of Standard of Care 2: Failure to Obtain Informed Consent
As cervical spine manipulation does carry a risk of stroke, the standard of care for dictates that the defendant must obtain informed consent before performing cervical spine manipulation. What follows is a statement of informed consent statement to the risk of cervical artery stroke from cervical spine manipulation that meets the standard of care:
The two main arteries (blood vessels) in the neck are the vertebral artery and the internal carotid artery, they are referred to as the cervical arteries. There is a rare condition known as an arterial dissection (a tear in the inner lining of an artery) that may cause the development of a blood clot with the potential to lead to a stroke. I understand and am informed that research does not show a causal relationship between cervical spine manipulation and cervical artery dissection in the presence of a normal, healthy cervical artery.
With respect to strokes, if cervical artery dissection is present, then there is a risk that cervical spine manipulation could exacerbate the condition and cause a cervical artery stroke.
I understand and informed that the Doctor of Chiropractic will evaluate my condition on every visit to this office. If symptoms of cervical artery dissection are present, I will not receive cervical spine manipulation. I will instead be referred for CTA (CT angiogram) evaluation and emergency medical care.
If there is not a signed, written informed consent statement, with some version of the above wording, then the defendant has breached the standard of care and failed to obtain written informed consent to the risk of cervical artery stroke due to cervical spine manipulation. It is also the standard of care that there should be a doctor/patient discussion of informed consent documented in the patient’s chart, and the consent form should be signed by the doctor and the patient.
Breach of Standard of Care 3: Failure to Diagnose & Refer Arterial Dissection
When cervical spine manipulation is done in the presence of an existing cervical artery dissection, causing an immediate cervical artery stroke, the standard of care dictates that the defendant may be held liable for causation of the stroke. However, the standard of care dictates that the defendant may also be held liable for failure to diagnose and refer the existing cervical artery dissection, which could have avoided the stroke.
This standard of care also applies to cases where stroke does not occur immediately after cervical spine manipulation. So, in a case where stroke occurs minutes, hours, days or weeks after manipulation, the plaintiff may not have a case for causation of stroke by manipulation, but they could have a case for failure to diagnose and refer a pre-existing cervical artery dissection. But for the failure of the defendant to diagnose and refer, the plaintiff could have received CTA imaging and emergency medical care sooner and avoided the stroke.
The defendant may reference 2008 and 2017 studies by Cassidy which found that although there is an association between cervical artery stroke and chiropractic visits, there is a similar association between cervical artery stroke and primary care provider (PCP) visits. As the two most common symptoms of cervical artery dissection are neck pain and headache, the research found that patients tend to seek clinical care, chiropractic and otherwise, for headache and neck pain caused by cervical artery dissection. Cassidy concluded that patients with neck pain and headache reporting cervical artery stroke after chiropractic and PCP visits likely had an arterial dissection before their office visit, so cervical spine manipulation did not cause the cervical artery dissection.
The plaintiff should point out that the study itself shows that doctors of chiropractic, and PCPs, often fail to diagnose and refer cervical artery dissection for proper treatment. This even when the two most common symptoms of arterial dissection, headache and neck pain, are present. Even if there is no evidence that cervical spine manipulation caused the cervical artery dissection or an immediate stroke, the defendant may still be liable failure to diagnose an existing dissection and refer for emergency treatment.
These studies also show that attorneys should evaluate any PCPs involved in the case for failure to diagnose and refer arterial dissection. DCs are not the only physicians who fall beneath the standard of care in these cases. Any physician who saw the plaintiff while they were having symptoms of cervical artery dissection may be liable for failure to diagnose and refer.
Unfortunately, researchers still often assume a causal association of cervical spine manipulation and cervical arterial dissection, and dismiss studies that show no causal connection. So much so that the failure of a physician to diagnose and refer a cervical artery dissection is not even considered. This bias has significant negative consequences for cases involving manipulation and stroke. Numerous episodes of litigation are focused on non-existent causation of arterial dissection by cervical manipulation, when failure to diagnose and refer pre-existing arterial dissection is evidenced by the records.