By Deborah Kan
An official diagnosis of Alzheimer’s disease often doesn’t emerge until a patient has died and undergone an autopsy. This is because brain scans can be very expensive and the only scan that shows the beta-amyloid plaque build-up is a PET scan, which can cost around $5,000. But scientists are now using imaging to understand how the disease attacks the brain. I recently spoke to Professor Nick Fox, director of the Dementia Research Centre at University College London, about how imaging can help find a cure to Alzheimer’s disease.
- Scans used to look for early signs of Alzheimer’s disease
- Scans focus on hippocampal or ‘memory’ portion of brain to look for shrinkage
- Tracking Alzheimer’s brains could make trials more efficient
Being Patient: What are the benefits of early diagnosis to an Alzheimer’s patient?
Prof. Nick Fox: What it really means, as much for the family as well as for the patient, is that people get the right treatments. But it also means that we can give people support and advice about what the future holds. It also ends what people have called ‘an agony of not knowing’ – when we know that there’s something wrong, where somebody’s not behaving right or they don’t seem right, and we’re wondering why it is. That is crucially important.
Being Patient: Tell me a little bit about diagnosis, because we often hear that it’s impossible to diagnose without a special PET scan.
Prof. Nick Fox: With these (diagnostic) tests we’re improving our clinical certainty. In the past, to be sure clinically, we had to wait until people were more affected. Now with these tests, we are confident enough that we can say, “memory problem and a positive scan.” We think we have enough certainty to say, “Yes, this is early Alzheimer’s disease,” and that’s an advance.
Being Patient: Tell me a little bit about the scanning technique that you have spent so much time researching, and what it means to diagnosis.
Prof. Nick Fox: We know that Alzheimer’s disease attacks particularly vulnerable parts of the brain early on. Now with the machine techniques that we have got, just with an MRI scan, which is a non-invasive scan of the brain, we can look at those areas, which are very related to memory, and see if they’re shrinking. So that will say, “Right, this is not just depression or somebody over anxious about their memory.” It really is an organic problem; it’s a real problem with the brain, and that is likely to be Alzheimer’s disease.
Being Patient: Are you able to diagnose patients with Alzheimer’s before they have any symptoms?
Prof. Nick Fox: We are making progress so that research studies and trials will be able to take place in that pre-symptomatic stage. At the moment, the real added value is when people already know there’s a problem, already have got symptoms, and we can give people greater certainty, and sooner than previously.
Being Patient: What does it mean, though, to be able to diagnose earlier in the longer term if it becomes accessible to people, like you and I who don’t have signs of Alzheimer’s, to actually detect that we may be getting Alzheimer’s before we have any symptoms? Does that mean we’ll live a longer life?
Prof. Nick Fox: We don’t think there’s any value in giving people information about future risk where we can’t do anything significant about it. So we do not advocate screening. It’s the same thing that happened with cancer. When we have effective therapies, early screening will be valuable. But not at this stage. At this stage, what the big opportunity is being able to do trials earlier.
Being Patient: The numbers, obviously, are staggering today, and they’re only going to increase (more) in number, as more people are diagnosed. Is there anything we know today which can prevent the onset of the disease?
Prof. Nick Fox: There are a number of things we know that we should be doing to look after our brains, the most important of our organs, and we know there are a number of things that we can do. We should not be smoking. We should look after the brain in terms of brain trauma. It’s a very delicate organ and head trauma’s not a good idea. Looking after your blood pressure, your cholesterol, keeping physically and mentally active are all helpful in reducing our risk. But that will still leave us with people who do all the right things, (who) will still get Alzheimer’s disease. What we need is therapies that are going to really intervene at a biological, molecular level.
Being Patient: What does the ability to scan and track an Alzheimer’s brain mean for research?
Prof. Nick Fox: We’ve got lots of potential therapies and there are two ways this imaging, I think, can make a big difference. First of all, we can make trials more efficient, faster, so that we can test more treatments. The other thing is that we’ve opened up a window of opportunity that was never there before. It may well be that the most effective way of slowing this devastating disease is intervening before too much damage is done. Imaging gives us that window. In fact, it may be the only way we intervene effectively.
Being Patient: Can you give me a brief description of what we we are looking at in terms of your research and what you found through scanning the brains of people for as long as 20 years?
Prof. Nick Fox: What we know from many groups around the world, converging evidence, is that proteins build up in the brain that are toxic, perhaps 15, 20 years before people get symptoms. Then after that, but still before symptoms, we can see vulnerable areas of the brain starting to shrink.
Being Patient: Do you think in the future that a scan may be a normal procedure accessible to everyone?
Prof. Nick Fox: Absolutely. I think in the same way that what we do was revolutionized in cancer, once we have effective therapies, it may well be that simple. It could be blood-based; it could be imaging-based, biomarkers, and a diagnostic test that will be assessing people. Once we have effective therapies. That’s what we’ve got to do.
Being Patient: So it’s not worth it now, before you have a cure?
Prof. Nick Fox: No. People need to do the sensible things, live their life to the full, but not have their life ruined by anxiety about something for the future.