The medical world must sell optimism because its researchers are competing with those in many other areas for limited grant money; its nonprofit organizations, including research universities, rely on donations that also pay their staffs’ salaries; and its physicians must maintain their patients’ hopes for a cure to prevent their sinking into despair and compounding their disabilities.
Today, a close colleagues asked me if I think there will really be a cure for PSP any time soon. I knew that if I said no, she would have kept it to herself and not denounced me for disloyalty to the philosophy of optimism that rules the medical culture in which I live. So, unafraid to say no . . . I said yes.
I think that in the next few years, our ever-increasing knowledge of the far-upstream events in the process that kills brain cells in PSP will have yielded plenty of addressable drug targets. Drug development is more fruitful than ever and will probably come up with something for at least one of those targets. Some of those may be existing drugs for other conditions, allowing us to avoid most of the time-consuming safety testing required of new drugs. New measures of drug efficacy in PSP will shorten the time required for drug trials.
The quest for early diagnostic markers will probably yield something along the lines of an easy blood test with which to screen people in their 50’s and 60’s and more difficult and expensive, but specific, imaging tests to evaluate those with a positive blood test. This means that the treatment could be prescribed very early in the course of the disease, when it’s most likely to work.
I caution that this isn’t the same as discovering the cause of the disease and avoiding it, as we can do for many conditions of infectious, toxic or traumatic cause. What I see for PSP is more like what we do for many cancers these days – detecting it early, killing or removing it before it spreads, and keeping an eye out for recurrence. Another example of the same idea is diabetes, where without knowing or fixing the underlying cause of the disease, we can prescribe medication and lifestyle modifications that allow a normal lifespan rather than the few years’ survival common a century ago.
Keep in mind that this type of “cure” would not repair damage that has already occurred. Once the disease process has destroyed a lot of brain cells, it may be impossible to replace them good as new. There certainly are ongoing efforts to do that – it’s called regenerative neurology. But the complexity, number and physical length of the brain cells’ connections disrupted in PSP are daunting. Once they’re lost, things like growth factors or stem cells probably won’t bring them back without breakthroughs in basic scientific knowledge that I don’t see coming soon. If I’m right, the best that a person with established PSP could hope for in the next few years would be a way to halt the ongoing progression. But that alone would be a triumph.
So, yes, even among trusted friends, I’m an optimist about curing PSP in the near term.
2 thoughts on “PSP doc tells all”
so my question is what would a person experience when they are 50 or 60 years old to even send them for this blood test so that it can be identified that they might have PSP? Or are we saying that it would be a part of a routine blood test that all people would take. Or would it be only for those who have had a connection to PSP, like a family member, mother or father? I pray every day that we do get to a point where we can identify it early enough so that we can treat it. HOPE
Good question. To paraphrase: If we can’t screen the entire population in the PSP age group, how would people be chosen for screening?
Answer: It’s possible that any screening test for PSP would also work for Alzheimer’s, and if there’s a good treatment for that, then there could be reason to screen the entire population in their 50s and 60s. In such a scenario, people who screen positive would then receive a more specific test that could separate PD from PSP from normal. But if the screening test is only for PSP, then people could be chosen for screening on the basis of a family history of PSP (as you suggest) or for any symptom vaguely suggestive of early PSP such as personality change, tripping or dizziness.
A problem with mass, indiscriminate screening for a rare disease is that false positives could far outnumber true positives. So the screening test for PSP would have to have a high “positive predictive value.” We don’t yet have such a test, but I think we will before long.