Stroke in the U - Logan Class of December 2011



Stroke in the U.S.

    Stroke, as a general medical problem, is significant as it affects more than 700,000 Americans annually. In the United States, it is the third leading cause of death, the major cause of disability and the primary reason for nursing home admission. Because of the aging U.S.  population and the increased incidence of chronic illnesses, the rate of stroke will continue to increase.

    It stands to reason that some of these people will be chiropractic patients and some will be under care at the time they stroke. This program will attempt to better define the types of strokes that are associated with chiropractic manipulation and to help develop skills in the management of this complication.

Stroke in the U.S. “Stroke” is a general term, much like “cancer.” Specifically, stroke is a loss of blood flow to the brain. There are two types of stroke:

Ischemic- loss of blood flow due to blockage.

Hemorrhagic – loss of blood flow due to bleeding, often from an aneurysm.

    It is essential to understand that the ischemic type of stroke is the only one which is associated with manipulation.

One author states, “While there continue to be numerous attacks within the media about this issue, the consensus among the scientific and research community is that the related incidence between a chiropractic neck adjustment and stroke is greater than 1 in 1 million and statistically is considered coincidental.”

Stroke: Introduction

    Another example of chiropractors denying a relationship between manipulation and stroke is the Chiropractic Association of Ireland which states media reports are “an attempt to discredit chiropractic and discourage people from seeking care from doctors of chiropractic” and that “some proponents of allopathic medicine continue to disseminate misleading information about a possible link between cervical adjustments and strokes. It is the position of the Chiropractic Association of Ireland that such misinformation is a deliberate and unethical scare tactic that does not stand up to critical analysis.”

If one investigates, one will find other groups within the chiropractic profession whom also deny the very existence of a connection between stroke and manipulation. For example, one author states stroke is exceeding rare, the relationship of manipulation and stroke hasn’t been proven and the allegation must be an attack on the profession. This same author offers the argument that reports of manipulation causing stroke in the scientific literature are “junk science” and that adjustments are remarkably safe. The clinical seriousness of brain injury from vertebral artery trauma requires the claim that manipulation does cause stroke in some people be reviewed.

    There is a serious and larger group in the profession, and the scientific literature, which would argue that there is a rare but established connection between manipulation and stroke from vertebral artery injury. Terrett states, “It has to be accepted that vertebrobasilar syndrome following spinal manipulative therapy (SMT) does occur. The temporal relation between young healthy patients without osseous or vascular disease attending a SMT practitioner, then suffering these rare strokes is so well documented.”

The other prime argument in support of those who connect stroke and manipulation is the strong anatomical explanation. Although the vast majority of people well tolerate manipulation, the underlying anatomical explanation, which will be covered in this program, is compelling. As Terrett points out, denying the connection “offers no help in:

- Accepting the problem

- Addressing the problem, or

- Searching for solutions to the problem.”

This course will cover the following topics:

- The Clinical Problem

- Anatomical review

- Mechanics of VA injury

- Incidence rates

- Patient profile of stroke patients

- Clinical presentation of stroke

- Signs and symptoms

- Malpractice issues with stroke

The Clinical Problem

      Spinal manipulation is a safe and effective form of care that Smith and Carber found is utilized by over 66,000 chiropractors in the United States. Statistically, there are few complications from spinal manipulation and its safety is reflected in low premium rates from malpractice carriers. Numerous studies continue to relate the effectiveness of chiropractic manipulation for a variety of conditions. These studies are covered in detail in other courses on this website's calalog of classes, e.g.  "Benefits of manipulation."

       The clinical problem is that a very small number of patients experience vascular complications from cervical manipulation. These complications result in ischemia of the brainstem or cerebellum (located in the posterior 1/3 of the brain) and serve as a focal point for those who are critical of manipulation in general and chiropractic in particular. Because stroke is the most serious complication from cervical manipulation, and the focus of critics of the profession, it deserves closer study.

Vertebrobasilar Insufficiency

      Although Chiropractic Manipulative Therapy (CMT) is extremely low risk procedure, it should be acknowledged that injury to the vertebral artery (VA), or stroke, is a rare but real complication that does occur even in the hands of experienced and careful clinicians. Injury to the internal layer of the VA can eventually cause occlusion of the artery and cause a clinical emergency known as vertebrobasilar insufficiency (VBI). To better understand this rare, but serious complication, a review of the vertebral artery anatomy is required.

Vascular Supply of the Head

        The vascular supply to the head is provided by the vertebral and carotid arteries that arise from the arch of the aorta. The circulatory workload is divided between two systems

• The vertebral arteries supply the circulation in the posterior one-third of the brain.

• The carotid arteries supply the anterior two-thirds of the brain.

• The strokes that arise from manipulation affect the vertebral arteries and affect the posterior one-third of the brain. Any connection to stroke in the anterior two-thirds of the brain from manipulation, is highly speculative. For this reason, our course will predominately concentrate on the vertebral arteries and the posterior one-third of the brain.

    

Vertebral Artery Anatomy

      The right vertebral artery normally arises from the right subclavian artery, moves upward, and enters the transverse foramen, usually at the sixth cervical vertebrae. Occasionally, the vertebral artery will enter a transverse foramen at a higher spinal segment.

    The left vertebral artery normally arises from the left subclavian artery. It also moves upward and enters the protective border of the transverse foramen at C6. The vertebral artery passes through the transverse process at each level.

Vertebral Artery Anatomy

       Anatomical studies by Chopard have revealed the vertebral artery is "fixed to adjacent structures in the fibrous osteomuscular tunnel by means of a continuous lamina of collagen along its entire course.“ This means the VA can not slide inside the transverse foramen at each vertebral level. The vertebral artery is fixed and will be elongated as the cervical spine is rotated. Normally, this is well within the normal function of the vertebral artery.

        It is theorized that excessive rotation between C1 and C2 results in tearing of the interior wall of the VA (the tunica interna). This will be discussed further in this program.

Size of the Vertebral Arteries

       Although the course of the vertebral artery remains fairly constant, the size of vertebral artery will vary from person to person. Clinically, the size of the vertebral arteries can be significantly different in some individuals. Some patients will have a markedly smaller or hypoplastic vertebral artery on one side of their neck versus the other. The left side is usually the larger of the two sides. Eskandari, in his discussion of vertebral artery atherothrombosis, states a single, normal caliber, vertebral artery will provide the proper vascular supply in these people.

        People with a single, functional VA and a poorly functional hypoplastic VA are at higher risk for VBI. If the dominant VA is compromised, little collateral circulation is available to the hindbrain via the Circle of Willis.

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|Bow Hunter's Stroke |

|    Several branches arise from vertebral arteries as they ascend the cervical spine. The small branches enter the intervertebral |

|foramen and help supply the spinal cord with proper vascular supply. Once the vertebral artery exits the atlas it turns abruptly in a|

|posterior direction and moves through the groove on the superior surface of the posterior arch, just behind the lateral masses. It is |

|at this location that some patients develop partial or complete ossification termed a ponticulus posticus.  The vertebral artery can |

|be entrapped in this area and affected by head rotation. Injury in this manner has been termed a "Bow Hunter's stroke.” Each vertebral|

|artery, once they cross the vascular groove on the superior surface of the atlas, moves medially. |

[pic]

Arterial Wall Composition

    The lower section of the vertebral artery is characterized by its higher percentage of elastic fibers which reside in the tunica media. The percentage of elastic fibers reduce to a normal level and the artery takes on a more muscular character as it rises. Chopard found the elastic fibers in the vertebral artery to reside chiefly in the most external layer of the tunica media and they were close together in formation. By the most cranial segment of the basilar artery the elastic component becomes homogeneously distributed in the whole of tunica media. The lower elastic portion allows stretching to accommodate the force of the pulse. The higher muscle portion helps squeeze the blood upwards.

Normal Vertebral Artery

    Digital subtraction angiograph of the left vertebral artery is seen on this image. This a normal examination. Note the smooth caliber and even filling. These features reflect the absence of injury or underlying pathology. It is possible to see the VA move laterally at C2, the rise through the C1 level and then move medially to form the basilar artery. Most VA injuries occur at the C1 level.

[pic]

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|Upper Vertebral Artery |

|        The final branches of the vertebral arteries usually arise intracranially and are termed: |

|1) anterior spinal artery |

|2) posterior artery |

|3) posterior inferior cerebellar artery or PICA. |

|    The anterior spinal artery is a thin branch which arises near the termination of the vertebral artery. They descend just anterior |

|to the medulla oblongotta and join into a single anterior spinal artery within 2 cm of their origin. It then continues to descend, |

|supplying blood to the anterior surface of the spinal cord. |

|Vascular Supply to the Spinal Cord |

|    The VA also supplies arterial blood flow to the cervical spinal cord. |

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|1.    Basilar artery |

|2.    Vertebral artery |

|3.    Ant. Spinal artery |

|4.    Radicular artery |

|5.    Radiculomedullary artery. |

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|The PICA arises from the distal end of the vertebral arteries and are generally recognized as the last and largest branch from the VA.|

|The PICA supplies additional branches which cover the medulla, the inferior vermis, the lower aspect of the fourth ventricle, the |

|inferior cerebellar hemisphere and the tonsil. As seen is common with many vascular structures, there is anatomical variation and they|

|are generally asymmetrical in size and absent in about 20% of patients. If the PICA is absent the anterior inferior cerebellar artery |

|(AICA) provides vascular flow to the areas the PICA would have normally supplied. |

|Why is the PICA Important? |

|      The PICA is frequently involved in cases that involve manipulation and stroke. The inner layer of the vertebral artery may have |

|been originally injured. The flow of blood in the VA slowly lifts the inner layer and, if it reaches sufficient size, can form a flap |

|and occlude the VA or cover the small opening from the VA to the PICA. This flap will then occlude the blood flow into the PICA and |

|result in an ischemic stroke, usually to the lateral medullary area. This ischemia from of stroke will be discussed shortly in this |

|course. The next page will compare a lateral angiogram of the VA, basilar artery and the PICA to an anatomical drawing. |

|[pic] |

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|Upper vertebral artery angiogram |

|Digital subtraction angiogram of the vertebral artery (lateral view). Note the occlusion and decreased flow in the superior segment of|

|the vertebral artery. The caliber and flow of the VA is diminished in the section supplying the PICA. The basilar artery is seen as |

|the superior segment. |

|[pic] |

|Angiogram of the Basilar Artery |

|        This study represents a digital subtraction angiogram of the left vertebral and basilar arteries during  the early filling |

|phase. The left vertebral artery is not filling. The straight segment after the right VA is the basilar artery. It later branches |

|right and left into the posterior cerebral arteries. [pic] |

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|MR Angiogram of the Basilar Artery |

|MR angiogram of the basilar artery. The  vertebral arteries enter at the lower right and join to form the basilar artery (2). Branches|

|include the anterior inferior cerebellar artery (AICA) (1), the superior cerebellar artery (3) and the posterior cerebral arteries |

|(PCA). |

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|MR Angiography of the Circle of Willis |

|   MR angiographic techniques can also be enhanced with the aid of computer graphics. The individual images can be reconstructed into |

|a three-dimensional image that can be turned and manipulated. The image on the right with three arteries that are "rising." The paired|

|arteries on the side are the right and left carotid arteries. The single artery is the basilar artery that has arisen from the right |

|and left vertebral, which are not seen. These three arteries then give off branches and provide the interconnections that form the |

|Circle of Willis. This is all from the perspective of looking down on the Circle of Willis. |

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|    Such image manipulation has limited use in the evaluation of most patients. However, it does show the radiologist's ability to see|

|structures that are difficult to visualize. |

|Anterior Brain Circulation |

|        As noted earlier, the circulation to the anterior two-thirds of the brain is provided by the carotid arteries. These arteries |

|rise through the anterior portion of the neck and divide into the internal and external carotid arteries. The external carotid |

|branches to supply the face. The internal carotid (ICA) enters the skull through the carotid canals of the temporal bones. The ICA |

|branches into the opthalmic artery and the middle cerebral artery. |

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|Carotid Angiogram |

|       Normal angiogram of the right carotid artery. The internal carotid artery branches to the right, and the external artery |

|branches to the left. Strokes in this anterior circulation are more common than posterior circulation strokes. |

|[pic] |

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|Anterior Brain Circulation |

|Lateral angiogram of the right middle cerebral artery, assisting in circulation to the anterior 2/3 of the brain. The carotid arteries|

|are not typically injured in manipulation, although several cases are cited and claimed in the literature. |

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|Mechanics of VA Injury |

|        Vertebrobasilar insufficiency (VBI) is one of the more serious clinical complications that can arise from manipulation. As |

|previously described, the vertebral arteries move laterally at C2 to enter the inferior aspect of the transverse foramen. Once they |

|cross the transverse foramen, they move medially and follow the superior surface of the ring of the atlas. They enter the spinal canal|

|area and turn superiorly and meet in the midline, forming the basilar artery. The ability of the atlas to rotate on the odontoid |

|allows stretching, compression and torsion of the VA and a secondary fluctuation of the blood flow. In some individuals the atlas has |

|the ability to cause total occlusion of the blood flow in a single VA, but symptoms will not arise because the cerebellum will receive|

|a collateral vascular supply from the other VA. |

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|        Researchers have performed studies on the vascular flow to assess the actual impact of atlas rotation on the vascular flow in |

|the VA. Rotation of the head will affect the flow on the contralateral artery. Thus, rotation of the head to the right will affect the|

|left VA. It is theorized that the excessive stretching of the VA upon extreme atlas rotation and will cause a tear of the intimal or |

|innermost layer of the VA. |

|VA Injury |

|        The tear in the VA has the potential ability to cause ischemia in several ways. The tear can result in local vasospasm that |

|serves to constrict the VA. The torn intimal wall can also be worsened by the flowing blood. The torn flap has the ability to be |

|slowly separated from the middle layer. The enlarging flap can then either occlude the lumen of the vessel or cover the opening of |

|another artery, such as the origin of the PICA. |

|Injured VA in VBI Patient |

|        Digital subtraction angiogram is seen here of the left vertebral artery. Note the multiple areas of stenosis and decreased |

|flow. The superior segment has been closed by an intimal flap. This VA has lost the normal characteristics of smooth caliber and flow |

|seen in the angiogram earlier. This patient had a severe ischemic stroke. |

|[pic] |

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|MRI: PICA Infarction |

|        MR of the cerebellum reveals an area of infarction in the area supplied by the posterior inferior cerebellar artery. This is|

|represented by the area of high signal intensity (white area of the image) on the left side. Symptoms from such an infarct will |

|likely include vertigo, nausea, vomiting, blurred or double vision. Kim has also reported he has encountered extremity symptoms from |

|PICA infarction. |

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Wallenberg’s Syndrome

    The Wallenberg's syndrome is caused by an occlusion of the Posterior Inferior Cerebellar Artery (PICA). Symptoms may include ataxia, loss of pain and temperature on the ipsilateral side of the face and contralateral side of trunk. Horner’s syndrome, vertigo, nausea and vomiting. Hoarseness, dysphagia and even intractable hiccups.

     In many patients, these symptoms will respond to care and the patient will improve in some areas. Residual symptoms, however, are all too frequently encountered.

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| |Medial Medullary Syndrome |

| |        MR of the cerebellum reveals an area of infarction to the anatomical areas supplied by the vertebral artery. This |

| |infarction, seen by the intense white area on the right, is more medially located than the Lateral Medullary Syndrome. It |

| |may also arise with VA injury and causes  paralysis with atrophy of half the tongue, and paralysis of opposite leg and arm.|

| |Review of the literature reveals Medial Medullary Syndrome is quite rare. |

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MRI: AICA Infarction

        This MR study of the cerebellum reveals an area of infarction in the area supplied by the anterior inferior cerebellar artery (AICA). In this patient, the infarct is represented by the area of high signal intensity (white area) on the left side. Symptoms are variable, but will frequently include vertigo, nausea, vomiting, tinnitus, ipsilateral Horner’s syndrome and even sudden deafness.

[pic]

Incidence rates of VA injury from CMT     

Manual procedures, such as manipulation, have been identified as a rare but possible cause of injury to the vertebral artery. The incidence of such injuries has been examined a number of times in the literature. As no study has the ability to count all possible cases, reviewers must perform estimates. Some studies have estimates based on reports from neurologists who encounter the injury in their practice. Other studies have proposed incidence rates based upon the incidence of the injury encountered in large clinical programs such as chiropractic colleges.

Survey of Literature Studies

Carey          1993      1:5.85 million manipulations

Dabbs         1995      1:2 million manipulations

Klougart     1996      1:900,000 manipulations

Dvorak        1985       2-3 serious events/million CMT

Hosek         1981       1:1 million manipulations

Cyriax         1978       1: 10 million manipulations

Incidence: Summary   

     No matter which study is cited, or which analysis method is used, it is clear that the actual incidence rate is far lower than many complication rates for other tests or treatment procedures currently used. Nevertheless, injury to the vertebral arteries can occur and the chiropractor would be well advised to be clinically alter to the possibility that such a complication can exist. The subtleties of the initial symptoms assoicated with VA injuries will be discussed next by this program.

Profile of the Stroke Patient:

        One of the areas of continual concern is the identification of a patient who may have vascular complications with cervical manipulation. Opinions in these areas arise from either personal experience in reviewing such cases, reviewing a series of cases or a review of the literature. Although there are commonalities in these methods, some differences are also exist.

        The age of patients involved in VA related strokes are characteristically younger than those patients with intracranial, hemorrhagic strokes. For example, Vernon noted the average age of manipulation induced strokes to be 37.9. Terrett reviewed 255 cases in the literature and the age of the patient was identified in 233 of the cases.

        Terrett’s review revealed the range for such strokes was 7-87 for males, and the average age was 39.5. Female stroke victims ranged in age from 20-74 and the average age was 38.3. Thus, it seems that the average age for these patients is in the late 30s for both men and women.

        The sex distribution of the stroke cases is somewhat more controversial. The majority of cases reflected in the literature are female. Vernon states the female to male ratio is nearly 2:1, with females being the larger number. This would imply that females are at a greater risk for manipulation induced stroke.

        Haldeman performed a recent review of 64 cases and noted 64% of the stroke victims were female and 36% were male. The average age was 36.3 years of age with a standard deviation of 6.1 years. Some 90% of the 64 cases were younger than 45 years of age. 92% of the patients presented with cervical spine complaints. Of interest, 25% of the patients had complaints of a new type of head and/or neck pain, which was often extremely severe and had a sudden onset.

Incidence Rate of CMT and Stroke

Clinical Presentation of VBI Patients

        The clinical presentation of patients can be divided into symptoms before the stroke and those after the stroke. Symptoms before the stroke. Presenting complaints may vary widely as the literature frequently cites presenting symptoms which actually have no relation to the stroke. However, experience has shown that some presenting symptoms may be especially relevant.

    First, as reflected in the Haldeman study, the index of clinical suspicion should rise when a patient presents with a headache/neck pain that is not normal for them. Many patients will actually state “I have never had a headache like this before.” These type of headaches seem to frequently localize to the upper cervical spine and behind an ear. This is thought to be pain from an arterial dissection.

Initial Complaints Before the Stroke

        As previously noted, Haldeman reviewed 64 cases, 16 of which were experiencing new pain that was sudden and severe in onset. “Of these 16 patients, 4 complained of dizziness or vertigo and three patients had nausea or vomiting.” Two had numbness, one had numbness and tingling in the face, hands and feet and one had transient paresthesia in all limbs. One patient had tinnitis and one had visual disturbances.

Initial Complaints Before the Stroke

       There are other presenting symptoms that are associated with cerebellum dysfunction and may indicate the early stages of an approaching stroke. Dizziness, unsteadiness, and vertigo are all signs that indicate the patient may be in the early stages of VBI. Chiropractors too frequently attribute these symptoms to “low blood sugar” or other causes. When in doubt, it is best to have the patient examined by others for a second opinion. This is especially true when the patient tends to have other findings such as hypertension, bruits, or history of smoking.

What about George’s test?

        Various tests, including the one developed by Dr. George, attempt to screen and assess the vascular status of a patient before cervical manipulation. George’s test is performed by taking blood pressure and pulses bilaterally, checking for bruits and holding the neck in extension and rotation for 30 seconds in each direction. The maneuver was done to try and duplicate VBI signs of nausea, dizziness or nystagmus. If VBI symptoms appeared, it would be considered a positive test and the cervical manipulation would not be performed.

While the test was well intended and used for decades, it now seems that it does not work well for the intended purpose. For example, Doppler ultrasound studies have shown that head rotation can cause occlusion of a VA. On the other hand, Bolton reported on vascular screening tests being performed on patients who were known in advance to have occlusion of a VA and theperformance of George's test failed to demonstrate a positive finding. This would certainly argue against the use of George's test.

        Even listening for a bruit, which is part of George’s test, lacks sensitivity as it requires a 50% occlusion of the VA before the bruit develops. Despite these problems, many still recommend George’s test be performed. The test is cheap, non-invasive, easy to perform and a low risk procedure. Although not totally reliable, it may identify a person at risk for vascular injury. If the test fails, it still shows the doctor attempted to screen for a condition with the best test available in a chiropractic office. Questionable findings in the test would be further indication to delay the cervical manipulation for a second opinion or additional testing.

Symptoms after the stroke:

    VBI after manipulation may cause a constellation of different symptoms, depending on the location of ischemia, degree of occlusion and the degree of collateral circulation. Symptoms of ischemia in the posterior circulation include nausea, vomiting, ataxia and slurred speech. Other, less common symptoms, such as tinnitus and vision disturbances may also occur.

Clinical Presentation of VBI Patients After Manipulation

         The last element of stroke symptoms concerns the timing of their onset. Symptoms of nausea, vomiting, ataxia and slurred speech will usually start almost immediately after vascular occlusion. In many cases, these symptoms will start before the patient leaves the office.

        In such cases, the actions of the chiropractor within the first few minutes are critical. Any of these symptoms should be assumed to represent vascular injury, until proven otherwise. Paramedics should be summoned and DO NOT re-manipulate the patient. One must avoid the temptation to manipulate the patient in the opposite direction in the hopes of reversing the new symptoms.

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| |Fibromuscular Dysplasia |

| | It should be understood that some patients may have underlying pathological changes in the artery that can make the VA's |

| |more susceptible to injury. Fibromuscular dysplasia (FMD) is such a condition as it produces localized thickening and |

| |weakening of the arterial walls. FMD most commonly affects the renal arteries where it propensity to thicken the arterial |

| |walls causes renal artery stenosis and hypertension. The pathological changes include the production of abnormal amounts of|

| |elastic fibrils and fibrous connective tissue, along with a loss of smooth muscle in the tunica media of the artery. |

| |The cause of FMD remains far more illusive than the radiographic changes. One theory is that it is produced by repeated |

| |dilation of the artery. Other studies reviewed 37 cases of FMD and have found a familial link, particularly with females, |

| |and cite genetics as the cause. Others believe FMD starts as a local defect in the elastic framework of the artery. No |

| |matter the cause, it has the ability to weaken arteries, including the VA and makes them more susceptible to dissection. |

| |The image on this page is a digital subtraction angiogram of the vertebral artery (late phase). Note the numerous |

| |constrictions, consistent with fibromuscular dysplasia. These multiple constrictions produce the "string of pearls" |

| |appearance. Compare this irregular lumen of the VA in this angiogram to the normal. smooth lumen in a normal vertebral |

| |artery. |

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| |Cerebellar Effects of VBI |

| |        The previous patient with FMD suffered an tear of the inner or intimal layer of the vertebral artery after being |

| |manipulated by a “holistic medical doctor.” The resulting flap occluded the lumen of the vertebral artery. This not only |

| |produced immediate neurological effects, but also resulted in long term anatomical changes. The next three images are the |

| |brain CT scans of this same patient with FMD over a 97 day period. These serial scans will reveal some of the anatomical |

| |changes that may occur with ischemia. Click on each image to enlarge. CT scan, axial view, non-contrast. This patient’s |

| |scan was taken on the day of a right VA dissection, secondary to manipulation and FMD. There are no signs of ischemia on |

| |the left side of the image. |

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Cerebellar Effects of VBI, cont.

CT scan, same patient seen earlier, 65 days after the stroke. The density of the ischemia in the lower left corner has decreased as the surrounding tissues expand. This results in a darker area on the CT scan (left lower portion, 7 o'clock position), consistent with the collection of CSF in the area.

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Cerebellar Effects of VBI, cont.

Same patient 97 days after the stroke. The density of the brain tissue has decreased further and approaches that of CSF. The size appears smaller and the sharpness of the border has increased due to expansion of the other tissues.

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Other Causes of VA injury

       Manipulation is not the only cause of VA injury and, at times, other etiologies exist. Some of which have been identified in the literature. These causes included playing tennis, star gazing, “head banging in heavy metal band”, painting a ceiling, break dancing, sitting in a barber chair, yoga, archery, wrestling, amusement park ride, turning head while driving, rapid change in head position, self-induced manipulation, and whiplash.

        The preceding list outlined many activities that have been identified in the literature as a cause of vertebral artery injury. Although the activities appear to be quite dissimilar they have cervical extension and head rotation as a common biomechanical feature. Even innocuous activities such as having ones hair washed at the beauty shop, which involves extension and rotation, can cause VA injury in a susceptible patient.

Malpractice Issues With Stroke

    As discussed in other Cevantive. courses, acts of negligence and malpractice are divided into two areas: Errors of omission and errors of commission.

An error of omission occurs when a doctor fails to do something that the reasonable doctor would have done in the same situation.

An error of commission occurs when a doctor does something that a reasonable doctor would not have done in the same situation.

In stroke cases, the doctor is susceptible to both types of errors.

        The errors of omission are best described as “failures.”  Examples would include failure to examine, failure to diagnose and failure to refer. Such "failures" can certainly come into consideration in a stroke case in a number of ways. First, unlike the 16 cases that presented with neurological symptoms in Haldeman’s review of 64 cases, most patients will present in a benign fashion that does not portend a potential problem with vascular supply to the head. This is why Haldeman concluded “vertebral artery dissection should be considered a random and unpredictable complication of any neck movement, including cervical manipulation.”

Errors of Omission

        A patient who will stroke after cervical manipulation will not typically present in a manner that can be identified before the event. This means that there is rarely some “fault” that can be laid at the feet of the treating doctor if a stroke occurs. The real issues arise once the patient has been manipulated and demonstrates signs of a stroke, such as nausea, vomiting, ataxia and slurred speech. In these few moments, the character of the office encounter changes and the doctor is now faced with a new set of decisions on a “new patient” that was not present before.

         After the patient suffers vertebral artery injury and exhibits new symptoms, the doctor is faced immediately with new clinical challenges. Unfortunately, many of these new and often rarely encountered decisions, must be made quickly and under adverse conditions. Prompt referral to a hospital is required. The immediate referral is needed as the current treatment for ischemic strokes includes treatment with tissue type plasminogen activator (tPA) within the first three hours of the onset of symptoms.

        We will next examine an example of an actual case that illustrates the potential for errors after a VA injury from manipulation.

Stroke and Manipulation, Ms. C

         Ms. C is a 37 year old female who had a history of headaches of five months duration. These headaches were of a different character than the migraines she had suffered as a teenager. Medical work-up in the preceding several months included an MR scan and a lumbar puncture to rule out multiple sclerosis.

        After consulting with a chiropractor, an examination was performed and a course of therapies and manipulation to the cervical spine was initiated. After one of the manipulations, the patient exhibited immediate nausea, slurred speech, dizziness and intense headache. She was unable to rise from the table and her husband was called.

        The patient was now clinically quite different than when she first arrived within the chiropractic office. No attempt was made to perform an additional examination. No referral to a hospital was made. Paramedics were not called. The doctor concluded the patient either had sudden onset of low blood sugar or was now in “migraine mode” for the first time since she was a teenager. Orange juice was procured for the “low blood sugar” at the chiropractic office.  The patient aspirated the orange juice and then vomited. The doctor then re-manipulated the patient in an effort to stop the symptoms.

        By this point the patient’s husband arrived and, after looking at his wife’s condition, he called 911 himself. Once the paramedics arrived the chiropractor told them this was not an emergency and suggested the paramedics take her home. The husband asked for his wife to be taken to the emergency room. The chiropractor’s parting comment as the ambulance door shut was “make sure they check your blood sugar.”

        The patient was examined at the ER and found to have a VA injury and a posterior circulation stroke. Marked residuals remained after treatment and the patient sued the doctor. The following allegations were made against the doctor:

Expert Analysis of the Case

      The expert witness for the patient cited the following issues.

Failure to examine. The doctor did not re-examine Ms. C once the new symptoms appeared.

Failure to diagnose. The doctor had two explanations for the symptoms, both of which were wrong. Stroke was never considered.

Failure to refer. The doctor never made an attempt to refer the patient in a timely manner to other doctors for proper diagnosis and treatment. In fact, the husband had to make the call for paramedics.

Re-manipulation of the patient. Given the immediate onset of symptoms after the first manipulation, it was below the standard of care to re-manipulate Ms. C.

Giving liquids to a stroke patient. Patients with nausea, vomiting, slurred speech and difficulty in swallowing should not be given liquids. The patient aspirated the liquids into her lungs, which later caused additional complications.

Did the doctor commit any errors of commission? Yes. All of the errors occurred after the patient sustained her stroke. The doctor failed to recognize or acknowledge the patient’s condition.

        The patient sued the doctor for malpractice and settled out of court with a structured settlement. The resolution of the malpractice case was followed by a complaint with the state board and the doctor’s license was placed on five years of probation.

        The preceding case involving Ms. C reveals many of the issues common to such cases. A high degree of clinical suspicion is required in such cases. The seriousness of the stroke complication requires it be considered as a diagnosis before other, less serious, conditions. Prompt referral is required for prompt medical intervention. The second consideration is to not make the condition worse. No subsequent manipulations are appropriate and should be avoided.

5-Minute Rules:

    The highest risk situation for any health care professional is being presented during an atypical, emergency problem, with little or no time to make important clinical decisions. This is similar to the police officer that suddenly confronts several heavily armed men, firing from a building and holding hostages. The potential for this “regular policeman” to make bad decisions is enormous. The best scenario is to call the SWAT team and a hostage negotiator. The danger is still high, but for these people the situation is no longer atypical and they usually attempt to defuse the situation to obtain more time.

    A similar situation occurs when a chiropractor is confronted with the patient who has suffered a stroke in his or her office. The problem is serious, atypical and the doctor has only a few minutes to recognize the atypical problem and make prudent decisions. This is even more difficult when one considers that most chiropractors have never seen a patient with VBI.

     The actions the doctor takes in the first 5 minutes after a stroke will often determine if the doctor is successfully sued for negligence or exonerated by the facts. The most important action is to correctly diagnose the condition and summon emergency care. Waiting for the symptoms to hopefully resolve is an incorrect plan of action.  Prompt referral to a hospital is required as current treatment for ischemic strokes includes treatment with tissue type plasminogen activator (tPA) within the first three hours. Prompt referral is critical. The longer brain tissues do not receive oxygen, the greater the likelihood of permanent damage. This is akin to a child drowning in a pool. The longer the child was underwater (without oxygen), the more ominous the clinical prognosis. Getting the patient to a emergency room is of utmost importance. Some have urged the public to think of strokes as “brain attacks” much the same as “heart attacks.” Emergency care is required.

    Certain presenting signs and symptoms require rigid rules to help determine a correct plan of action. For example, medical doctors are taught all gastro-intestinal bleeding is deemed to be a carcinoma, until proven otherwise. They are taught coughing up blood is considered to be a carcinoma, until proven otherwise.

    In each of these presenting situations, there could be some less serious explanations. Blood found in the stool could simply be a result of an internal hemorrhoid and not cancer. However, a well trained and reasoned clinician must rule out the more ominous possibilities. In this case, given the fact that colon cancer is one of the leading causes of death, out weighs the fact that such testing is expensive and uncomfortable.

    In the practice of chiropractic there are only a few conditions which present as emergencies. The most significant of these emergency situations is stroke.   A good rule would be to assume any type of ataxia, slurred speech, vomiting… is a stroke until proven otherwise. If a patient presents with a severe, acute, atypical headache, it may be wise to consider the possibility of etiologies other than those associated with subluxations of the cervical spine.

The Most Dangerous Patient

    As was pointed out earlier in this course, there may be on occasion a patient may be experiencing the initial stages of vertebral artery injury when presenting to a chiropractor’s office. The symptoms can be so generic the doctor can easily mistake the presenting condition as a benign entity. Certainly pains arising from the lateral aspect of the neck and radiating into the head do not represent an unusual set of presenting complaints to many, many practicing chiropractors.

    The problem arises when such a patient presents to a chiropractor’s office. As the presenting complaints are typical and benign, chiropractic care is begun. Over the course of the next few hours or days, the vertebral artery may continue to tear, leading to occlusion. The symptoms from the slow tearing can be equally subtle. Unfortunately, the subtle nature of the symptoms do not allow for a correct differential diagnosis.  The signs becoming more frank and localized as the tear worsens or as a piece of thrombus breaks off and seeds itself in the brainstem causing infarct.  As a result this may cause many to erroneously conclude that manipulation(s) was/were the genesis of the stroke. Such cases are legally difficult as the nature and extent of the patient’s injuries and medical costs will most certainly attract allegations of negligence.

    The previously described clinical scenario represent the most dangerous patient to visit a chiropractic office. The doctor would be well advised to be acutely aware of the subtle  signs and symptoms which may be indicative of a slow tearing of the VA. A high degree of clinical suspicion is required. Any type of dizziness, ataxia, vomiting… should be viewed as a stroke, until proven otherwise.

Case Presentation

    Carefully review the following actual case of manipulation induced stroke. Analyze the case presentation to determine the potential errors made by the doctor. Would knowledge of the 5-minute rules have helped this patient and doctor?

Summary & Conclusions

    

• There is a rare, but real association between stroke and manipulation

    

• Vertebral arteries supply the posterior 1/3 of the brain’s blood supply

    

• The internal carotid artery supplies anterior 2/3s of the brain’s blood supply.

    

• Manipulation induced strokes are almost always associated with the vertebral arteries.

    

• Females are 2:1 more often associated with manipulation related strokes. Late 30s is the average age associated with both male and female manipulation related strokes.

• There are a number of other activities associated with the onset of VBI.

 

• There are very few symptoms which would help the doctor of chiropractic to identify the existence of a vertebral artery injury, before stroke occurs.

• Any signs of ataxia, slurred speech, vomiting… must be considered a stroke until proven otherwise.

    

• Presenting complaints of acute onset of severe atypical head pain, and pain which is located behind the ear, should be viewed as possible indicators of VA tearing.

    

• The most important action taken if a patient has ataxia, slurred speech, vomiting… is to correctly identify the presence of a stroke.

    

• Manipulation is never indicated in a patient who has paralysis, slurred speech, vomiting…

Nystagmus, a rapid oscillation of the eye, is a potentially serious sign, especially when it is initiated by a change in cervical spine rotation. Since nystagmus is not common, this short video demonstrates a downbeat nystgmus. The presence of downbeat nystagmus suggests a lesion in the cervicomedullary junction. Causes include Arnold-Chiari's syndrome, spinocerebellar degeneration, stroke and multiple sclerosis.

Homocysteine

   So what about other potential causes of vertebral artery dissection? Some of the most interesting research involves the effect of homocysteine on the vascular system. Dr. Rosner has written on the potential relationship between homocysteine and vertebral artery injury. Dr. Rosner states, “The newer models of arterial disease center around inflammation as being just as important a determinant as elevated cholesterol and triglyceride levels, if not more so. Plasma homocysteine has been identified as an independent risk factor for cardiovascular disease. Numerous mechanisms have been proposed to account for this anomaly, including:

(a) promotion of endothelial dysfunction of coronary resistance vessels

(b) increasing oxidative stress, known to promote myocardial dysfunction; and

(c) stimulating left-ventricular remodeling brought on by the increased cardiac fibrosis and activation of matrix metalloproteinases.”

    Dr. Rosner also noted, “With high homocysteine levels having been correlated for years with strokes and arterial dissections, it is easy to imagine how elevated levels of this metabolite may have brought on many of the vertebral arterial dissections that have hounded the chiropractic profession for years.” Click here for additional information on homocysteine’s negative effects.

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   The latest comprehensive review of VBA stroke and chiropractic care was found in Spine, Vol. 33, Number 45, pages 176-183. Their study spanned nine years and reviewed 818 cases of VBA strokes admitted to Ontario hospitals. The following are the key points from their study.

Key Points

• Vertebrobasilar artery stroke is a rare event in the population.

• There is an association between vertebrobasilar artery stroke and chiropractic visits in those under 45 years of age.

• There is also an association between vertebrobasilar artery stroke and use of primary care physician visits in all age groups.

• We found no evidence of excess risk of VBA stroke associated (with) chiropractic care.

• The increased risks of vertebrobasilar artery stroke associated with chiropractic and physician visits is likely explained by patients with vertebrobasilar dissection-related neck pain and headache consulting both chiropractors and physicians before their VBA stroke.

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