I read about experimental Alzheimer’s tests that can detect early stages of the disease. Are these really helpful?
Answers from Ronald Petersen, M.D.
An important first step in developing a treatment plan for any disease is having a clear diagnosis. New Alzheimer's tests may help with early detection of the disease. However, before these become widely available, more research is needed to determine who might benefit from them and what they reveal about the progression of Alzheimer's and other diseases.
- Biomarker test. Researchers have proposed an Alzheimer's test that measures two proteins, beta-amyloid and tau, in cerebrospinal fluid. The doctor removes a sample of the fluid that surrounds your brain and spinal cord by using a needle inserted into your spinal canal (lumbar puncture). The fluid is examined for evidence of abnormal development of beta-amyloid proteins, which form plaques, and tau proteins, which form tangles. Both plaques and tangles are thought to contribute to the development of Alzheimer's disease. These proteins can help identify people with mild Alzheimer's disease and mild cognitive impairment (MCI) who are likely to progress to more-serious forms of the disease.
- Brain imaging (neuroimaging). Brain imaging — using equipment to record images of changes in the brain — is another area of research. Researchers are studying use of imaging techniques, such as magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, used in conjunction with radiotracers. These radiotracers are charged particles that "light up" Alzheimer's affected areas in images of the brain — for example, by attaching to proteins associated with Alzheimer's disease.
- Cognitive assessment. Technology is also being used to develop software for computer-based assessments that detect cognitive changes and may be useful in the early diagnosis of Alzheimer's disease.
Early detection and diagnosis of Alzheimer's disease is an important goal. Early intervention with medications may slow the progression of the disease and provide a better opportunity to plan for the future.
Ronald Petersen, M.D.
Sep. 01, 2011
- Shaw LM, et al. Cerebrospinal fluid biomarker signature in Alzheimer's disease neuroimaging initiative subjects. Annals of Neurology. 2009;65:403.
- Petersen RC (expert opinion). Mayo Clinic, Rochester, Minn. July 2, 2011.
- Inside the brain: An interactive tour. Alzheimer's Association. http://www.alz.org/alzheimers_disease_4719.asp. Accessed June 29, 2011.
- Earlier diagnosis. Alzheimer's Association. http://www.alz.org/research/science/earlier_alzheimers_diagnosis.asp. Accessed June 30, 2011.
- Maruff P, et al. Validity of the CogState Brief Battery: Relationship to standardized tests and sensitivity to cognitive impairment in mild traumatic brain injury, schizophrenia, and AIDS dementia complex. Archives of Clinical Neuropsychology. 24;2:165.