FW: CCWG Information Bulletin - December 23, 2002

[Guest guest]

These are the last two reports until after

the New Year.

H. Dallas, D.C.

President, Western States Chiropractic College

Phone (503) 251-5712

Fax (503) 251-5728

CCWG Information Bulletin

- December 23,

2002

Information

Bulletin

From the Chiropractic Communications

Working Group

Wednesday, December 18, 2002

Dr. Cheung

Returns to Witness Stand

Dr.

Gordon Cheung, a neuroradiologist at Sunnybrook and Women's College

Health Sciences Centre and a witness for the family, returned to the stand

under cross examination by Mr. Tim Danson, counsel for CMCC and The CCA.

Under

oath Dr. Cheung admitted that Dr. Murray Katz had written his will-say

statement for the inquest, to which he signed his name. Dr. Cheung indicated

that in his September

20, 2001 report, which he had prepared

himself, he attributed Ms. ' dissection to chiropractic based on two

material factors: neck pain and temporal association. He stated that in his

mind all of the facts fit; the medical records from the Queensway

General Hospital, the

results of the angiogram, the recent headaches, and the severe neck pain

suffered following her visit to the chiropractor.

Mr.

Danson asked Dr. Cheung how he came to a conclusion on the severity of Ms.

' neck pain. He responded that based on the notes in her hospital

records the pain must have been severe, and one would not expect a patient to

go to emergency if the pain was just mild. Mr. Danson then asked Dr. Cheung if

he would agree with the experts that the pain associated with an arterial

dissection is so severe that it is like no other pain a patient has ever

experienced? Dr. Cheung disagreed, added that he has seen patients with mild

neck pain, yet the diagnosis has been a dissection. He stated that if it was a

small dissection there may be a 'new and different' pain yet it

might still be mild, but if there was a large dissection this would likely lead

to severe pain. Mr. Danson asked if Ms. might have gone to the hospital

because she had a stroke. Dr. Cheung agreed that this could have been the case,

however, he was not that familiar with all of the details of Ms. '

case.

Next

Mr. Danson asked Dr. Cheung " If he was to learn that what he understood

about the timing and severity of Ms. ' neck pain to be false, would

it impact his diagnosis as to the cause of her death? " Dr. Cheung indicated

that he would consider all of the facts in the case, but that it would not lead

him to re-evaluate his diagnosis. He added that the evidence could not be taken

out of context, that there was a large dissection seen on the angiogram, and

neck pain was present. Based on this information he could not conclude anything

other than a dissection at C1/C2 caused by the neck adjustment. Mr. Danson

asked Dr. Cheung if he was aware that Ms. had been at work on the days

following her chiropractic treatment, and the week leading up to her stroke?

Dr. Cheung stated that even with a dissection this could have been possible.

Dr.

Cheung testified that he had no knowledge of chiropractic or how an adjustment

works, nor that Ms. had only been adjusted on the right side.

Nevertheless, he believed that the force of the over-rotation and

hyper-extension has a bi-lateral effect, enough to cause injury to the artery

on either side. Dr. Cheung stated that in his work at Sunnybrook he sees at

least four cases a week of dissection attributed to mild trauma such as turning

one's head, playing sports, and other rotational type injuries. He added

that dissections from all forms of neck trauma are under reported, most

specifically from rotational type injuries. Mr. Danson suggested that this was

mere speculation on Dr. Cheung's part. Dr. Cheung countered that this was

not the case and that one does not have to be a chiropractor to understand the

mechanisms involved.

On

the matter of what caused Ms. ' stroke, Dr. Cheung indicated that he

believed it was trauma following chiropractic manipulation which caused a

stroke and that a clot could be seen from C1 to the top of the basilar artery.

He further indicated that: both the left and right side were dissected. He

noted that the vessel on the left was occluded, and no blood flow was getting

through. Dr. Cheung pointed out that the dissection on the right side appeared

to have some irregular tissue surrounding it, which could have broken off and

caused one of the strokes.

Mr.

Danson then asked about the evidence already presented to the jury that both

intracranial hemorrhage and atherosclerosis were present in Ms. '

case. Dr. Cheung testified that he disagreed with the assessment that there was

atherosclerosis present, and indicated that a possibly sudden dissection at

C1/C2 could have caused the hemorrhaging further up on the left side. Dr.

Cheung added that the angiogram indicated that the artery was occluded at C1.

He agreed with Mr. Danson that there was 70% stenosis in the right vertebral

artery, but disagreed that it represented atherosclerotic plaque. He further

disagreed that there was atheroscleroosis at the location of the thrombus. Dr.

Cheung testified that while atherosclerosis is associated with stroke, patients

are generally not symptomatic until there is at least 70% stenosis. In Ms.

' case, he suggested, there was no stenosis but some atherosclerotic

hardening in the arterial wall. He further added that patients are more likely

to survive a stroke if the atherosclerosis is in the vertebral arteries rather

than in the carotid arteries.

Mr.

Danson asked Dr. Cheung if he was aware that neither Drs. Deck nor Pollanen

found an extracranial dissection? He indicated that he was, and suggested that

had he been involved in this case, he would have asked them to go back and

re-examine their findings and that perhaps they were not looking in the right

area. Dr. Cheung went on to state that other neurologists had seen the

dissection in Ms. ' case, but did not record it. Dr. Cheung stated

that in the preparation of medical reports, some things are an automatic given;

therefore, not everything is stated in writing. He added that if it is a

classic dissection, you don't need to spell it out. He indicated that he

was confident that he had come to the right conclusion in his diagnosis of this

case.

Mr.

Danson then challenged Dr. Cheung on how he was able to find a large dissection

extra cranially which the pathologists missed. Dr. Cheung suggested that Mr.

Danson ask the pathologists how this could happen, but added that the area from

C1 to the top of the vertebral artery must have been filled with something,

because we see it on the x-ray. Mr. Danson then suggested that it is not

uncommon for observations to differ from when a patient is alive, versus what

is seen post mortem. Dr. Cheung agreed, but added that he was not saying that

Drs. Deck and Pollanen were wrong, perhaps they looked at the wrong slides

since what they found did not match what was seen in the angiogram. Mr. Danson

asked if on this point, Dr. Cheung would be willing to defer to a pathologist.

" No, not at all, " stated Dr. Cheung. Mr. Danson, challenged the

witness on this point, stating that the pathologists might miss something

small, but not something very large. Dr. Cheung disagreed noting that this is

not uncommon. Dr. Cheung also stated that he did not see any evidence of

calcification in the arteries, as noted by Drs. Pollanen and Deck, when viewed

on the angiogram. He noted that calcification is easily identifiable with this

diagnostic tool.

On

the issue of drawing a causal link between dissection and neck manipulation,

Dr. Cheung indicated that he was not familiar with Dr. Sackett's work.

While he could not cite the rules of causation, and admitted that he knows

little about epidemiology, Dr. Cheung stated that in this case he felt that he

could draw a causal relationship, as he had reviewed the entire clinical

picture and was drawing this conclusion based on clinical experience. Dr.

Cheung later testified that he was not aware of Ms. ' family medical

history including hypertension, migraine, family history, and smoking.

Following

the lunch break, Mr. , counsel for the chiropractor, began his

cross-examination. Dr. Cheung told the jury that he did develop a differential

diagnosis in preparing his report for this inquest, but noted that the

pathology reports were difficult to follow. He further indicated he did not

recall if he reviewed Ms. ' chiropractic records, but that of all

the documents presented to him, he reviewed those that interested him. Dr.

Cheung added that he knew Ms. had received a chiropractic cervical

manipulation, as it was mentioned at least 20 times in the various reports.

On

the matter of how dissections are classified, Dr. Cheung testified that

according to the Canadian Stroke Consortium only about 20% of dissections are

considered to be truly spontaneous. Fifty percent can be clearly linked to

inflicted trauma (i.e. a gunshot wound, sliced artery, etc.), while the balance

are the result of minor trauma such as rapidly turning your head, playing

sports, or some degree of rotation. Mr. then asked if Dr. Cheung could

explain biomechanically how an adjustment could cause injury to both the right

and left arteries? Dr. Cheung stated that it is a rotational injury and that he

sees this type of thing all the time.

Mr.

suggested to Dr. Cheung that he could not clearly see the arterial

damage all the way from C1 to the top of the vertebral artery. Dr. Cheung

agreed, noting that there are some areas which could not be seen on the imaging

tests, and that he relied on the reports of others.

Dr.

Cheung stated that he had no knowledge as to the number of slides that had been

produced in this case, or if 507 slides was a large number. Mr. asked

for some clarification on how large the blockage in Ms. ' left

artery really was. To this, Dr. Cheung responded that he was unable to tell,

but it was large enough to occlude the vessel, and that the blockage on the

right side appeared smaller. He added that based on the angiogram, a dissection

seems more likely than stenosis. Dr. Cheung stated that looking at the

angiogram, you cannot tell if the bulge is in the media or intima, but it would

not be in the adventia, and he disagreed with Dr. Pollanen that it was an

artifact.

Ms.

, counsel for the College of Chiropractors of Ontario, proceeded

with her cross-examination. Ms. pointed out earlier testimony heard by

the jury that a dissection could not have healed in the time between Ms.

' last adjustment and the time of her angiogram. Dr. Cheung begged

to differ with that opinion, and indicated that there was evidence in the

reports that supported his belief that there was healing. He noted that in his

clinical experience he had seen dissections heal within one week.

Dr.

Cheung again reiterated that from both the initial x-ray and overall evidence,

there was total consistency to support his position that the dissection was

caused by neck manipulation or trauma to the vessel. He added that there was no

way a thrombus would stick to the wall of an atherosclerotic lesion, and that

with the high velocity of blood flow in the head the formation of a lesion would

not be likely.

Testimony

concluded for the day.

Thursday, December 19, 2002

Dr. Cheung

completes testimony, and inquest recesses for holiday break

Thursday

morning saw the conclusion of testimony from Dr. Gordon Cheung,

neuroradiologist and witness for the family. This was followed by submissions

from various counsel on several matters, and mid-way through the afternoon the

Coroner adjourned the inquest until January 2003, at a date to be announced.

The Coroner did state that the inquest would not recommence prior to January 6.

The Coroner noted that there are still three witnesses to be heard: Dr.

, neuropathologist whose testimony has not been completed; Dr. Brad

, neurologist; and Dr. Cairns, Deputy

Chief Coroner, Investigations.

The

day's testimony from Dr. Cheung began with a question from one of the

jurors who asked how Dr. Cheung was certain there wasn't other

intervening trauma that might have led to Ms. ' stroke? Dr. Cheung

responded that there was nothing in the medical record to indicate such trauma

except for the fact she had a neck adjustment.

Questions

on re-examination from several counsel followed-up on the juror's

question. Mr. Danson and Mr. each noted that evidence heard at the

inquest from employees of Glaxo-Wellcome indicated that Ms. worked during

the week following her adjustment, and asked Dr. Cheung if this would change

his opinion that she had been injured by the adjustment? Dr. Cheung responded

that patients can miss the symptoms, and just because she was able to work in a

" detail " job did not mean that she was not experiencing visual

impairment and other symptoms. When it was suggested that Ms. '

common law partner hadn't noticed any visual deficits, Dr. Cheung

indicated that Mr. Sweeney wasn't a medical doctor and Ms. could

have been compensating for the deficit without being aware of it.

In

responding to Mr. Danson's review of evidence that a right-side

adjustment at C1/C2 cannot cause injury to the left vertebral artery, Dr.

Cheung indicated that he doesn't accept that you cannot have a

double-sided injury (i.e. injury to both arteries from rotation to one side).

He also indicated, in response to Mr. Danson's questions, that he had not

read any peer reviewed studies confirming that a right-sided adjustment could

damage the left vertebral artery and that he was not aware of any studies

establishing the predicted value of the finding of a rat's tail (Note

- this was in reference to earlier testimony from Dr. Cheung where he

indicated that he saw a rat's tail in the extra-cranial left vertebral

artery and that this was indicative of a dissection).

Finally,

Mr. Danson asked Dr. Cheung about one of the slides from his presentation that

noted that only 2% of patients treated and discharged from hospital following a

dissection experience further complications. He asked Dr. Cheung why this did

not cause him to consider other events in Ms. ' case, and Dr. Cheung

responded that she probably didn't belong in the grouping of those who were

discharged from hospital as he was not sure that she should have been

discharged.

In

her questions to Dr. Cheung, Ms. , on behalf of the CCO, asked if Dr.

Cheung had identified references for his definition of the intima as a single

endothelial layer. Dr. Cheung indicated that he had obtained three references

from a search of the Internet. These were provided to counsel, and following a

break Ms. probed for the details on these references. Dr. Cheung

indicated that as it had been late at night, the library had not been open, and

he was a very busy individual, this had been all he was able to obtain. He did

not respond to Ms. ' question asking him the appropriateness of his

bringing forward to the inquest an article (the 3rd article) without

evening knowing the source of the information.

On

behalf of the two physicians, Drs. Dhanani and Knapp, Ms. Nicola asked Dr.

Cheung to explain his comments in response to an earlier question from Mr.

Danson wherein he indicated that he wasn't sure she should have been

discharged from hospital following her first stroke. Dr. Cheung indicated that

he wasn't thinking clearly when he gave that response and he was merely

trying to show that the probability of complications for patients discharged

following a stroke was probably higher now than 2%.

In

her re-examination of Dr. Cheung, Ms. Oakley asked Dr. Cheung about the

involvement of Dr. Katz in preparing his " will-say statement " . Dr.

Cheung indicated that Dr. Katz had asked Dr. Cheung to prepare the statement,

but as Dr. Cheung did not know how to prepare such a document Dr. Katz agreed

to prepare a draft for him. Ms. Oakley then asked Dr. Cheung about the 70%

stenosis of the right intra-cranial vertebral artery, to which he responded

that he does not believe there was 70% stenosis and he did not believe any

pathology report identified the stenosis. He also indicated that he felt that

the tinnitus (ringing in the ear) experienced by Ms. could not be

explained by plaque rupture but rather was indicative of injury.

The

examination of Dr. Cheung concluded with questions from Mr. Schneider, counsel

for the Coroner. Mr. Schneider noted that the evidence from pathologists in

this case has often been confusing and contradictory, and there have been some

problems with definitions and classifications. As such, he asked Dr. Cheung if

this made it more difficult for him to reach a conclusion in this case. Dr.

Cheung responded that it did not because on the angiogram and CT scans he felt

there was probably a dissection in the right intracranial vertebral artery, and

that he could definitely see a dissection in the left extracranial vertebral

artery.

In

concluding his questions, Mr. Schneider asked Dr. Cheung of his awareness of

the theory of genetic predisposition to arterial dissection, and whether this

theory impacted on his certainty that she had died as a result of the neck

adjustment? Dr. Cheung indicated that he was aware of this theory, but that he

was absolutely confident - " close to 100% " and " as

confident as he could be " - in his conclusion that Ms. '

death resulted from a rotational injury to the vertebral arteries as a result

of her neck adjustment on August 26,

1996.

Following

Dr. Cheung's departure, the day was taken up with submissions from

counsel on procedural matters. As reported above, the Coroner then called the

holiday recess.

Future bulletins

As

the holiday season arrives, there will be no more CCWG Bulletins until the new

year. All of us involved in the production of the CCWG Bulletins wish all

members of the profession and your families a safe and happy holiday and a

joyous new year.

Keeping in Contact

Please

contact us if there has been any change in your contact information. Reach us

by fax at (416) 482-3629; e-mail at infochange@...; or mail at Alumni

Affairs, Canadian Memorial Chiropractic College, 1900

Bayview Avenue, Toronto, Ontario, M4G 3E6.

In

the meantime, if you have questions about this bulletin, please feel free to

contact us by phone, fax or e-mail using the contact information listed in this

bulletin.

The Communications Working Group is

comprised of the following organizations:

Canadian Chiropractic Association:

Phone (416) 781-5656; Toll-free

1-800-668-2076; website www.ccachiro.org;

e-mail ccachiro@...

Ontario Chiropractic Association:

Phone (905) 629-8211; Toll-free

1-877-327-2273; website www.chiropractic.on.ca;

e-mail communications@...

Canadian Memorial Chiropractic College:

Phone (416) 482-2340; Toll-free

1-800-669-2959; website www.cmcc.ca;

e-mail communications@...

Canadian Chiropractic

Protective Association:

Phone (416) 781-5656; Toll-free

1-800-668-2076; e-mail CCPAcommunications@...