Early detection is key in slowing Alzheimer’s

The statistics of Alzheimer’s disease (AD) are impossible to forget and foolish to ignore.

More than 5 million Americans live with this degenerative neurological condition. By 2050, that number could be as high as 16 million. A recent study estimates that 46.7 million Americans have the earliest stages of Alzheimer’s brain pathology, which develops and progresses slowly for many years before the onset of overt symptoms.

Health care for persons with Alzheimer’s and other dementias cost the nation $259 billion in 2017. Since the 1990s, billions of dollars have been spent seeking an effective treatment that slows progression or reverses cognitive decline — without success.

An alternative approach to treatment for AD is prevention, which is at the forefront of a great deal of current research. Scientists have developed better ways to understand how AD develops and are studying an array of methods to detect the disease at its earliest stages. Many believe that effectively slowing — and ultimately preventing — AD will require sensitive tools for early detection. The goal is to be able to identify signs of AD before its key symptoms become obvious.

On Jan. 30, the UC San Diego Shiley-Marcos Alzheimer’s Disease Research Center (ADRC) in La Jolla will provide no-cost memory assessment appointments for seniors who may be concerned about the state of their current thinking abilities or who have a positive family history of Alzheimer’s disease.

We asked two experts on Alzheimer’s disease — Dr. Douglas Galasko, a board-certified neurologist and co-director of the Shiley-Marcos ADRC at UC San Diego School of Medicine and Dr. James Brewer, professor of neurosciences and radiology and interim chair of the Department of Neurosciences at UC San Diego School of Medicine — to talk about the looming threat of dementia, the value of memory screenings and improving prospects for early detection and prevention.

Q: Is dementia inevitable?

Galasko: Let’s rephrase this question as follows: If we all lived to 120, would we develop dementia due to Alzheimer’s disease or other factors? Studies have found that the risk of dementia accelerates with age, especially after 80; 50 percent or more of people in their 90s have significant cognitive impairment. However, there are well-documented cases of people with excellent cognitive function at age 100 or even older.

Brain research and new imaging methods during life have revealed that Alzheimer’s and other neuropathologies build up slowly and precede the onset of memory loss and dementia by a decade or longer. Some people are able to resist the effects of low-to-moderate AD pathology, and mechanisms of what is now called cognitive resilience or brain reserve are under study.

Many people with memory loss or dementia have combinations of Alzheimer’s and vascular (stroke-like) pathologies. As treatment for vascular risk factors such as hypertension and diabetes has improved, this may help to lower dementia risk.

Q: Should everybody have a memory screening, even if they’re not experiencing any memory issues or concerns?

Brewer: It’s a very personal decision. There are advantages to having an objective baseline with which to compare any change, should concerns crop up. If screening detects a potential problem, it often helps to know about it and work toward a diagnosis, particularly when the evaluation process uncovers an underlying medical condition that is treatable. Yet, even if the underlying process is untreatable and progressive, it is usually best to know about it before the symptoms become severe enough to cause additional problems.

Galasko: Troubling and progressive memory disorders are more common after the age of 65, and the risk rises with increasing age. Sometimes family members or friends may be the first to notice changes. If there is a concern about memory lapses or cognitive changes, it’s worth discussing with a physician, who may carry out a quick screen for memory abilities or refer to a specialist for a more detailed evaluation. In addition to aging, factors such as depression, anxiety, poor sleep, medical illness such as hypothyroidism, cognitive side effects of some prescription drugs or the aftermath of traumatic brain injury and stroke may contribute to changes in cognition. The good news is that many of these factors can be treated. If forgetfulness is more noticeable and impacts managing finances, recalling conversations, keeping appointments and taking medications on time, then an evaluation is essential.

For elders who are not noticing significant memory changes and are functioning well in daily activities, memory screening may be of less value, although it can help to establish a baseline. Medicare has recommended brief annual screening of memory as part of an annual Wellness evaluation for people aged 65 and over, but this has not yet become a routine.

Q: What are the early signs of AD?

Brewer: Most commonly, the earliest sign is memory loss, though not all memory loss is due to Alzheimer’s. Memory function in aged individuals can be affected by other causes of brain damage or dysfunction or simply due to aging. Patients in the early stages of AD tend to have difficulty making new memories that last more than a few moments. We would want to evaluate further if, for example, an individual starts repeating questions despite recently having been told the answer or seems to forget information as soon as he or she is distracted or moves on to another topic. Old memories from childhood through middle adulthood are remarkably spared until relatively late in the disease, so it is sometimes surprising to patients’ families when their loved one can recount childhood stories in remarkable detail despite having been diagnosed with Alzheimer’s disease. This is due to the way memories are stored in the brain and how the disease spreads in the brain. It causes its earliest damage to memory regions highly susceptible to the disease before progressing to involve a much wider set of regions.

Galasko: Cognitive changes, impolitely called “senior moments,” are part of getting older. There are differences between memory changes in aging and those typical of AD.

In the earliest stages of Alzheimer’s, problems may be intermittent, such as trouble recalling detailed conversations or complex or novel events or situations. Over time, the memory lapses become more consistent and pervasive.

In contrast, age-related changes may lead to difficulty retrieving words or names that often will come back later (the “tip-of-the-tongue” phenomenon). Aging also results in slowing of cognitive processing, greater vulnerability to being distracted and difficulty with multitasking. These factors can lead to losing one’s train of thought or not recalling something. When concentrating fully, someone with age-associated symptoms should still be able to learn and recall new information well.

Q: What are the prospects for a definitive test for AD?

Brewer: We have learned a great deal about AD, and, while many mysteries remain, we have a good sense of the biological processes involved. Physicians at UC San Diego Health, for example, have access to advanced imaging to assess regional neurodegeneration in the brain and are leading research studies that detect the abnormal protein deposits of AD using imaging or samples of spinal fluid. When a patient has a confirmed memory problem, we can use these kind of markers, when appropriate, to assess whether the problem is most likely caused by AD. These measures help determine which patients might be well-suited for clinical trials targeted to the pathological process of AD and also help direct our attention to other causes when the results are not consistent with AD.

Each patient and family has a unique journey with unique needs. Our hope is to personalize the treatment, so that patients and their caregivers receive optimal treatment using the latest approaches, all the while advancing the science toward eradicating the disease.

Galasko: There are emerging methods to detect Alzheimer brain pathology, even before symptoms have developed, that may help with screening and diagnosis for Alzheimer’s in the future.

LaFee is a health science writer at UC San Diego.

Memory screening

Mark your calendar: Free memory screenings on Jan. 30 for seniors 65 and older at UC San Diego Shiley-Marcos Alzheimer’s Disease Research Center, 9444 Medical Center Drive, Suite 1-100, in La Jolla. The 30-minute screenings include feedback about individual performance and information regarding relevant resources and research studies. To make an appointment, call (858) 822-4800.