Testing and Diagnosis

Before a definite diagnosis can be made, other factors such as tumors, strokes and infections must be ruled out. Also a differentiation between normal forgetfulness that may result from other sources such as depression, malnutrition and dementia associated with old age. Confusion, memory problems and abnormal behaviors can be treated simply by eliminating medications. An extensive examination including imaging and neurological examinations may be used to diagnose this disease in the living person. It is said the only definite way to diagnose Alzheimer's disease is from an autopsy. A diagnosis at an autopsy involves identifying the NFTs and plaques. Still, it is estimated that the maximum accuracy of diagnosis based on autopsy if 90 percent. There is evidence suggesting that there is altered brain metabolism as least two decades before the predicted onset of AD in the living person. There is evidence of NFTs associated with the E4 allele in individuals with normal cognition that died before they were able to fully express late-onset AD.

Prediction of age of onset with Apo genotyping cannot be used unless epidemiological data is provided from a variety of racial, ethnic and gender groups. In this same way that this kind of data is being collected for heart disease patients, it is also being studied for AD. It must be considered, though, that any differences found across ethnic lines and around the world can perhaps be explained by the differences in definition of dementia or in the methods of assessment. There are treatments now that are being used as they interact with the APOE genotype. One of these is Tacrin. Those patients that so respond well to this drug do not have the E4 allele. In a similar trial with a different drug, the responsive individuals did possess the E4 allele. This relates to benefits from future drugs will depend on ones biological risk factor, ApoE genotype. An ideal situation would be for the development of a drug that could protect microtubule associated proteins from forming paired helical filaments and increase their efficiency for microtubule stabilization, that could in turn retain dentritic integrity.

There are various genetic testing techniques available and those that are able to test for ApoE4. Since ApoE4 is a susceptibility gene but not a disease gene, it can help to only assess one's risk. This raises certain personal, social, legal and ethical issues, though that are two complex to deal with as a whole. The path to progress involves further understanding these interactions of this complicated and devastating disease, and continuing on our way to finding effective treatments and preventive measures in order to finally bring Alzheimers Disease under control.

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