As strange as this may sound, currently, there is no good scientific test for Alzheimer’s disease. In other words, there is no specific blood test, spinal fluid test, or brain imaging study (MRI, CT, PET) that can definitely tell whether you have the disease or not.

The diagnosis mainly rests on the neurologist’s clinical impression, which is based on an interview, examination, as well as some blood tests and an MRI of the brain to rule out other conditions which may mimic Alzheimer’s. Many times, especially during the early stages of the disease, physicians are uncertain of the diagnosis. Families are told that more time is needed to observe the patient, to see how the disease process unfolds. This uncertainty can lead to frustration.

The only real way to be 100% certain of the diagnosis is to autopsy the brain, which of course is not a good option in a living person.

Things may have just changed though, as the UCLA School of Medicine has announced they’ve developed a PET scanning technique that seems to offer the promise of a definite answer.

While still experimental, the scan utilizes FDDNP, a radioactive tracer that binds to the plaques and tangles typically encountered in the Alzheimer brain. The PET technique then provides physicians an actual picture of how much and where this tracer shows up in the brain.

I’d say this is significant breakthrough, as we are now much closer to identifying which people are going to develop Alzheimer’s disease years before they become symptomatic (see a related post discussing the early signs of dementia).

Additionally, the new study will enable researchers to more rapidly develop effective treatments, since they’ll be able to more objectively see what drugs are effective and which ones aren’t.

The study was published in the New England Journal of Medicine, December 2006.

Tags: FDDNP, MRI, PET-scan, plaques, spinal-fluid, tangles, UCLA-School-of-Medicine