Alzheimer’s disease affects 5.8million Americans. It is among the top causes of dementia. Alzheimer’s is challenging to diagnose in the initial stages because it does not exhibit any symptoms until later stages. Symptoms such as memory loss appear after neurodegeneration (which takes years or decades) has already taken a toll on cognition and memory.
Clinical trials that aim to reverse or slow down cellular damage brought about by Alzheimer’sdisease have failed repeatedly. Could it be because the drugs are administered too late? Researchers and scientists are yet to find out. The only way to ascertain the hypothesis is to find a way to diagnose Alzheimer’s disease in people with zero symptoms then test the drugs.
Scientific Developments for Alzheimer Diagnosis
Biological markers rely on tests of cerebrospinal fluid and brain scans, e.g., blood tests, MRI brain scans, cerebrospinal fluid tests, genetic tests, and PET brain scans. Biomarker tests show how the disease progresses 20 years before dementia starts. Early detection provides ample time for an intervention.
For the longest time, physicians could only provide a definitive Alzheimer’s disease diagnosis after the death of a patient. Doctors examine the brain tissue for the presence of tau and amyloid.
Scientists believed that the presence of amyloid and tau signal the development of Alzheimer’s disease. Unfortunately, scientists had no way to see the amyloid build-up in the living brain until 2002 when they developed the carbon -11(radioactive isotope of carbon). The isotope connects with amyloid, making it visible on a PET(positron emission tomography) brain scan.
Through amyloid PET, physicians can now conduct experimental therapy tests on people with signs of amyloid accumulation but no memory issues. It has also led to a revolution in the conceptualization of the disease. Physicians no longer consider Alzheimer’s symptoms for diagnosis; they use biomarkers to identify pathology.
Positive tau and amyloid biomarkers indicate Alzheimer’s disease. Advanced PET scans are more accurate than amyloid PET scans. However, various biomarkers track the progression of the disease at distinct stages.
Recent studies have managed to detect microscopic amounts of tau or amyloid in blood samples. According to recent research, scientists have been able to differentiate Alzheimer’s from other neurodegenerative diseases. If the blood tests for tau and amyloid demonstrate their reliability in diagnosing Alzheimer’s disease, more people will enrol in clinical trials. The tests will also eliminate doubts about the diagnosis and progression of Alzheimer’s disease.