“Doc, I was told at the hospital that my mom has dementia. Now that she’s here, I want you to tell me; does she have Alzheimer’s disease? Can you order a scan?”

It’s a question some of us in post-acute and long-term care settings have heard from families seeking clarity, support, and answers. Not too long ago, the only way to definitively diagnose Alzheimer’s disease was through a brain biopsy, an option that was clearly impractical outside of research or autopsy. But that’s no longer the case. In the past several years, remarkable progress has been made in Alzheimer’s diagnostics, offering new tools and new hope.

From Biopsy to Biomarkers
Today, we have access to two well-established methods that can help identify Alzheimer’s disease in its early stages, long before significant decline occurs.

The first is the amyloid PET scan. With this imaging technique, a radiotracer is injected into the bloodstream, binding to amyloid plaques in the brain. The PET scan then visualizes and quantifies amyloid levels, using something called “centiloids” to compare the patient’s results to those of a standardized population. This can help clinicians estimate the likelihood of Alzheimer’s disease, particularly in patients with mild cognitive symptoms.

Another approach, though more invasive, involves measuring cerebrospinal fluid (CSF) biomarkers through a lumbar puncture. In this method, we look at the levels of amyloid-beta and tau proteins, which change in characteristic ways in Alzheimer’s disease. This test has strong sensitivity and specificity and is especially useful for patients being considered for disease-modifying treatments, such as recently approved anti-amyloid therapies.

What About a Simple Blood Test?
There’s also growing interest in blood-based biomarkers, particularly the amyloid-beta 42/40 ratio. Research suggests that lower levels of this ratio might signal the presence of Alzheimer’s pathology. While this is an exciting step toward more accessible testing, the science isn’t quite there yet. These blood tests aren’t currently recommended as a standalone diagnostic tool or for treatment decisions—but they may play a larger role in the future.

Why This Matters in Long-Term Care
You might be wondering; how does this apply to our work in post-acute and long-term care?

While these advanced diagnostic tools are still most commonly used in specialty clinics and academic settings, they are beginning to reshape how we think about memory loss. For clinicians working in PALTC, staying informed about these developments is crucial. As therapies targeting early Alzheimer’s become more available, we may see a shift in when and how diagnoses are made and who is eligible for treatment.

Even if we don’t routinely order PET scans or lumbar punctures in our setting, understanding when to refer and how to counsel families is part of our role as advocates for patient-centered care.

The Takeaway
We’ve come a long way from the days when a definitive Alzheimer’s diagnosis could only be made after death. With tools like amyloid PET scans, CSF testing, and emerging blood biomarkers, we’re entering a new era of earlier and more accurate detection, one that opens the door to earlier intervention.

These advances may not yet be commonplace in the PALTC world, but they are coming. As clinicians, it’s our responsibility to be aware of what’s possible, so that when families ask, “Can you tell me if it’s Alzheimer’s?” we’re ready to answer, not just with knowledge, but with compassion and clarity.