Alzheimer’s Disease: A Physician’s Perspective

DOUGLAS GALASKO, MD, is a neurology specialist in San Diego, Calif, who has more than 41 years of experience in the medical field and is currently affiliated with the University of California San Diego Medical Center. He has a special interest in clinical and basic research on Alzheimer’s disease (AD) and other neurodegenerative disorders. In particular, he has focused on biological markers and genes related to AD.

BSTQ: How do you differentiate between the first warning signs of AD and normal forgetfulness associated with aging?

Dr. Galasko: Our brains and cognitive abilities change as we grow older, but not in a way that limits our ability to function. A person with AD has difficulty forming and retaining new memories — for example, richly detailed memories of conversations and events. In the earliest stages, this may occur inconsistently such as only when someone tries to recall a more complex or novel event or a highly detailed conversation or set of instructions. Over time, the memory lapses become more consistent and pervasive. Often, the person with AD does not notice or appreciate the extent of his or her memory changes, and a spouse or relative will report the problems.

BSTQ: When should someone be tested for memory loss?

Dr. Galasko: Troubling and progressive memory disorders are a problem primarily among people aged 65 years or older, although sometimes they can develop at a younger age. About two years ago, Medicare recommended general physicians include screening for significant memory problems during an annual wellness evaluation for everyone 65 years and older. However, there is no quick, easy and accurate way to do so, and false-positive screening can cause unnecessary distress and concern. A more focused approach is for someone with persistent memory lapses or cognitive changes to be screened and undergo medical evaluation if appropriate.

BSTQ: Is dementia preventable?

Dr. Galasko: We don’t know whether dementia would be inevitable if we all lived to, say, 120 years old or longer. Although the risk rises exponentially with age, and studies have shown about 50 percent or more of people in their 90s have significant cognitive impairment, there are well-documented instances of people with excellent cognitive function at age 100 years or even older.

Studies of the brains of people who underwent detailed testing during life and died in their late 80s or older show that dementia is often related to mixed pathology. AD pathology and vascular changes may interact. Also, based on pathology studies and on recent advances in brain imaging and testing that can identify AD changes in the brain, we know AD and other brain pathology builds up and precedes the onset of memory loss and dementia by a decade or longer. These findings raise hopes for prevention.

BSTQ: What approaches are used to prevent AD?

Dr. Galasko: An important approach is to address vascular risk factors. Changes in lifestyle, including eating a heart-healthy diet, maintaining regular physical activity and appropriately using medications to control blood pressure and diabetes, may all be helpful. Although the benefits of vascular health interventions may be the greatest when started as early as 50 years old, addressing vascular risk is appropriate at any age. Another approach specific for AD prevention is to intervene against early AD brain pathology as early as possible. Many novel treatments are being developed and tested with the goal of decreasing the extent of AD pathology in the brain. In the past, treatments have been studied in people with symptomatic AD. However, very early treatment may have the greatest benefit — before enough structural damage to the brain has occurred to cause impairment of memory and other cognitive processes.

BSTQ: Are there advances in screening and evaluation options?

Dr. Galasko: The University of California San Diego Shiley-Marcos Alzheimer’s Disease Research Center is playing a prominent role in two efforts to improve current practices. First, as part of the San Diego County Alzheimer’s Project, we have spearheaded the development of guidelines and tools to help doctors or other care providers to screen people with memory complaints. Second, with recently approved funding from the state of California, a group of AD centers at academic medical centers across California is developing guidelines and materials to support screening and evaluation of memory problems, which will include tools and information to help physicians make early and accurate diagnoses. And, we are exploring how tests can be used through apps or computerized testing. In terms of what’s in the pipeline, we’re also learning it is now possible to detect hallmarks of AD in the blood. This is being explored in promising research studies but is not yet available as a clinical test.