Meanwhile, don’t ignore the basic lab tests such as blood counts, blood sugar, metabolic panels, and so forth. “Most of the time you don’t find these things, but sometimes you do,” Dr. Caselli said, noting that other clinical tests such as those used for a variety of encephalopathies or fungal infections also can be useful. “I am looking for something I can fix, not just reinforce that the 82-year-old man in front of me with a 2-year history of progressive memory loss has Alzheimer’s.”
There is a wide range of other differential diagnoses to consider testing for in the appropriate setting related to vascular, inflammatory, infectious, nutritional, neoplastic, metabolic, and other pathophysiologic processes. Just remember, it isn’t always Alzheimer’s, and because we can’t ‘fix’ Alzheimer’s, it’s important to make sure we have ruled out all other reasonable possibilities,” Dr. Caselli said. Keep in mind there is a lot of mixed pathology in dementia, he added.
Genetic testing can be important in patients with early-onset Alzheimer’s and a family history because there are several known disease-causing autosomal dominant mutations that, if identified in the patient, may have implications for first-degree relatives, including children. Young adult children have important life decisions to make that could be influenced by their own genetic status. Genetic testing is less likely to be helpful in patients with late-onset dementia with or without a family history, because the results will not alter management. Biomarkers can indicate the actual presence of pathology, but at this point, do not offer a reliable time frame for the evolution of symptoms, he said.
Dr. Caselli receives research funding from Merck as well as the National Institute on Aging.
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