Alzheimer's blood test catches 90% of early dementia cases, study finds

A recent study has found that a combined blood test for cognitive decline can accurately identify 90% of early dementia cases related to Alzheimer’s disease. This test outperforms traditional diagnostic methods used by neurologists and primary care doctors, which have accuracy rates of 73% and 61%, respectively. The blood test measures the presence of plasma phosphorylated tau 217 (p-tau217), a biomarker indicating amyloid pathology, and is combined with the amyloid 42/40 ratio to enhance diagnostic accuracy. The study involved 1,213 participants undergoing cognitive evaluations in Sweden and confirmed the blood test's accuracy through spinal fluid analysis.

Dr. Maria Carrillo from the Alzheimer’s Association emphasized the potential of this blood test to revolutionize Alzheimer’s diagnosis and treatment, allowing for earlier intervention and lifestyle modifications. The p-tau217 test is particularly significant as it can detect neuronal damage associated with Alzheimer’s when amyloid plaques are present in the brain. Current diagnostic methods, including cognitive assessments and brain scans, often lead to misdiagnosis due to overlapping symptoms with other conditions.

While the blood test shows promise, further research is needed before it can be routinely used in primary care settings. Experts predict that if implemented, blood tests could significantly reduce wait times for Alzheimer’s treatment eligibility. In the meantime, lifestyle changes and preventive measures remain crucial for cognitive health.