Dr. Black: So this is a spinal fluid test which is showing the
level of certain proteins that are associated with the
brain disease in Alzheimer's disease. The fact that some individuals can have
this pathology and never express it as a dementia
is, um, one of the reasons that I think there's been a lot of interest in this paper, because
it raises a real ethical dilemma. Should people want to know this information
when it may never express itself? On the other hand, in
some people it will. And another part of the study was that in
individuals who actually were beginning to have concerns about their short-term
memory, and who on tests actually showed that their memory was not normal for
their age, then the presence of these protein
levels was very powerful in predicting who was
going to actually express the disease, and become Alzheimer's dementia.
In this particular study, they did show that if you had some symptoms
this was very powerful in predicting that you would progress over the next few years.
That's a different group, that's where it may be very important
eventually to have this information, because there might be something you can do about it, and because you have
a high risk of progressing, in fact, 100% of the individuals in the substudy where they
confirmed Alzheimers disease post-mortem, after death, at pathology
100% of those who had the profile in the CSF
went on to have Alzheimer's disease. So, the dilemma right now, is
that we actually don't have an effective treatment to prevent progression of the disease, but
the reason there's so much interest in this, is there is a lot of development going on
in the field of discovery of Alzheimer treatments, which means that we
may have, let's say, in the next 5 years, maybe longer,
some powerful ways of controlling the disease pathology.
In that situation, you would really want to have people at a mild stage, because there's probably
more you can do to prevent the full development of the disease.
You want to treat people who actually have the dementia, but being able to prevent the dementia would
have a huge benefit to society. So, that's why there's so much interest, and it may be
that if normal people were known to have this present in their spinal fluid
or on an imaging test, maybe they'd be followed more closely. But then, you have to
trade-off all the worry, and all the concern, when in fact we don't in fact have a treatment yet.
So, I think all of the interest in this result
in the press, and a lot of questions in our clinics and so on,
is because people want to know, "Should I know? Should I go and have this test?" And the answer 37 00:03:02,200 --> 00:03:02,190 is, right now, if you have Alzheimer's dementia and you're in clinics
is, right now, if you have Alzheimer's dementia and you're in specialty clinics
we have other ways of also being reasonably sure that you have the disease
but, these spinal fluid tests may become something that will be part of the diagnostic work-up.
It isn't the case right now, the government--who funds most of these
tests--would have to review it carefully and decide, but the evidence is mounting that this may be useful.
And, incidentally, in the Alzheimer's disease neuro-imaging
project--there were 5 Canadian sites, Sunnybrook was one of them--
we contributed to this study indirectly through the patients in the study that
we have been looking after. As far as I know, it actually isn't available
in Canada, however, it could easily be made available. I think
that the real issue is why, and what would you do with it. And right now there is no effective treatment
to stop progression of Alzheimer's disease. We're working toward that, but it's
not available. So, do we want to have that information now? I
think it's important to know that it will be available in the future, should we have something we can
actually do about it. But, you know, one of the problems with screening, is you don't want to screen just
for the heck of it, you actually want to be able to do something for it. Otherwise, people will get
very nervous and upset, because they may think their future
is worse than it actually is. So, you always have to be careful about how
we go about screening when you don't have anything specific to offer. It's quite different,
let's say, I mean if you find a cancer very early then you can do something about it.
You can save lives, that's a huge incentive to have
it done. We're not really there in Alzheimer's disease treatment.
Hoping to get there. My message is that there's a
lot of research activity that's leading to better ways of objectively
identifying the disease. This is good! This is very important, but we're not at
a stage yet where we have truly effective disease-modifying therapies where we can
stop the progression of the disease, or prevent the development of the disease. So we're, our
tools in some ways are ahead of what we're able to actually treat.
And so I think the message is stay tuned, keep informed, because
there's a lot happening--I mean, every month almost there's a lot happening--
still a way off from having the right treatments and understanding this very complex disease
well enough to be able to effectively prevent it or treat it.