Hitting a Nerve

Earlier diagnosis of Alzheimer’s: A good start, but then what?


In the October 2022 issue of JAMA Neurology was a research article and accompanying editorial on the ATN (amyloid/tau/neurodegeneration) framework for diagnosing and treating Alzheimer’s disease.

There are valid concerns with any system centered on early dementia diagnosis. If the new generation of Alzheimer’s treatments can reverse pathology before the symptoms are apparent, it certainly makes sense to treat people as early as possible. In a terrible disease with only partially effective treatments now, this is encouraging news.

Dr. Allan M. Block, a neurologist in Scottsdale, Ariz.

Dr. Allan M. Block

So this testing, as it stands now, would involve amyloid PET and tau PET scans, not to mention other screening tests such as MRI, labs, and the occasional lumbar puncture or EEG.

But it raises new questions.

Who should we be testing? If the new agents work on a presymptomatic basis, should we test everyone over 50, or 60, or 70? Or just those with memory concerns? Realistically, a lot of people come to general neurologists with memory worries, the majority of whom have nothing ominous. Those numbers are going to skyrocket as soon as the “have you been forgetting things? Ask your doctor” ads hit the airwaves. They’ll suggest, as much as the FDA will allow, that if you can’t find your car keys, you may have early dementia and need to be worked up promptly to keep from getting worse.

Who’s going to see these people? I’m sure it’s good for business, which I have no problem with, but most neurology practices are booked out a bit as it is. The influx of people panicked because they forgot their Netflix password will add to that.

How are we going to treat them? Even if we ignore aducanumab, which has more than enough baggage, lecanemab, donanemab, and gantenerumab are all waiting in the wings. Is one drug better for patients with certain scan findings? Or clearly safer? Keep in mind that, even at this early stage, we are already grappling with the potentially serious complication of ARIA [amyloid related imaging abnormalities]. The incidence is only going to go up as these new drugs enter the market. These questions rapidly move the drug outside the comfort zone of many general neurologists, and there aren’t nearly enough dementia subspecialists out there to handle the number of patients involved.

And lastly, from the more practical view, who’s going to pay for this? I’m not trying to prioritize money over people, but it’s a legitimate question that will have to be answered. PET scans aren’t cheap, and we’re talking about doing two of them. Neither are MRIs, or lumbar punctures. If we’re going to put guidelines out (like we do for mammograms and colonoscopies) for screening asymptomatic people over 70, or even mildly forgetful patients ... that’s a lot of dollars. Is there going to be some limitation on the testing based on who would benefit the most? What do we tell the patients and families outside of that range? And that’s even before we start factoring in the drug costs. In October, Forbes listed potential lecanemab prices as being anywhere from $9,000 to $35,000 per year.

I’m not trying to be Debbie Downer here. The fact that these drugs are here is, hopefully, the start of a new era in treatment of what will still be an incurable disease. Aricept (and its cousins) and Namenda were stepping stones in their day, and these are the next ones.

But these are questions that need to be answered. And soon.

Dr. Block has a solo neurology practice in Scottsdale, Ariz.

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