A new technique for blood tests could help researchers detect Alzheimer’s disease before it begins or patients show signs of dementia.

Researchers found a new approach that could be less invasive and costly than current brain imaging and spinal fluid tests.

Alzheimer’s disease is a toxic change in the brain that slowly destroys memory and thinking skills.

Symptoms first appear when people are in their mid-60s and the disorder gets worse over time.

PET scans of the brain and lab tests of spinal fluid can reveal disease-related changes twenty years before the onset of symptoms.

Although the disorder is not reversible, early treatment may help preserve daily functions and early diagnosis could start treatment tests.

Unfortunately, PET imaging is expensive and involves radioactive agents while spinal fluid tests are invasive, complex, and time-consuming. Researchers are looking for simpler, more cost-effective tests.

“The considerable time and resources required for screening research participants with PET scans and spinal taps slow the pace of enrollment for Alzheimer’s disease treatment studies,” says NIA Director Dr. Richard J. Hodes. “The development of a blood test would enable us to rapidly screen a much larger and more diverse group of volunteers who wish to enroll in studies.”

A team led by Dr. Adam Boxer at the University of California, San Francisco investigated whether the new technique called Simoa could predict Alzheimer’s disease development.

The process that destroys the brain involves two proteins called beta-amyloid and tau. Beta-amyloid clumps into plaques, which slowly build up between brain cells. Abnormal tau accumulates inside brain cells, forming tangles.

The team collected blood samples and measured the concentration of ptau181 which is a modified version of tau that’s been linked with Alzheimer’s disease.

The test could also differentiate Alzheimer’s from another group of rare neurodegenerative diseases.

The results of the blood test were similar to a spinal fluid test and a PET brain scan for beta-amyloid protein.

A research team in Sweden reported similar findings in a second paper published in the same journal issue.