Alzheimer's Disease: What is normal, what is not, and when to ask

Alzheimer’s Disease is a topic that receives considerable attention both from the scientific community and popular media, but despite the remarkable scientific breakthroughs over the past decade, there remain many unknowns about the disease. Given the field’s incomplete understanding of the disease, false speculation and misinformation can spread and gain popular acceptance rather quickly. The answers provided below outline our current understanding of the mechanisms and risk factors for development of the disease. In addition, we discuss the more controversial topic of current treatment options for Alzheimer’s Disease, with the expectation that our understanding of the efficacy and risks of such treatments will improve over time.

What is Alzheimer’s Disease, exactly?

All of us have two proteins in our brains called amyloid and tau. Alzheimer’s disease begins when those normal proteins misfold — they become sticky and toxic to brain cells. The proteins spread from one part of the brain to another, and over time that spread causes the changes in thinking and memory we recognize as the disease.

As we age, there is a higher propensity for those proteins to misfold. However, we do not have a full understanding of why the proteins begin misfolding in some individuals and not in other individuals. Our hope is that once we understand root cause, we will better understand risk factors, mechanisms of disease development, and ultimately more effective treatment options and measures of prevention.

Is Alzheimer’s a normal part of aging?

No. Aging is a risk factor for Alzheimer’s Disease, but it should not be considered normal to develop Alzheimer’s Disease.

Alzheimer’s Disease can affect younger individuals (we use the term “Early Onset” to define those who develop symptoms before the age of 65), but it is still very rare for Alzheimer’s Disease to cause symptoms before the age of 65. There are a couple of genetic syndromes that raise the risk of Early-Onset Alzheimer’s Disease, particularly Down Syndrome, likely due to having an extra copy of the chromosome carrying the amyloid precursor protein (APP).

Is it hereditary?

The vast majority of Alzheimer’s disease is not strictly and uniformly hereditary. Our genetics can influence risk of Alzheimer’s Disease, but in the majority of cases, our genetic makeup may serve as a risk factor rather than a verdict.

We like to use the analogy of a Mason Jar. There is only so much room in a Mason Jar. If we picture a Mason Jar full of rocks, we can draw the analogy of Alzheimer’s Disease like a Mason Jar that cannot fit any more rocks into the jar. If the jar overflows with rocks, in this analogy, that means that Alzheimer’s Disease has begun. We think of risk factors for Alzheimer’s Disease like one individual rock in the Mason Jar. Age is a large rock in the jar, gender is a rock in the jar, and other risk factors such as smoking, high blood pressure, diabetes, traumatic brain injury all represent other rocks in the jar. Our genetics are a medium-sized rock — they play a role, but for most people they are not the end-all, be-all cause.

In rare cases, one single gene mutation (located on 1 of 3 genes), could be a very large rock and the single main driving factor for development of the disease and in those cases, symptoms typically start before age 65. For anyone whose symptoms begin that early, we do recommend genetic testing. However, genetic testing is not routinely required or recommended for individuals with symptom onset after the age of 65.

What is the difference between Alzheimer’s and dementia?

Dementia is an umbrella term. It means a person is having trouble performing their day-to-day activities because of changes in thinking and/or memory. There are hundreds of different causes of dementia, including reversible forms of dementia (such as a nutritional deficiency or a thyroid imbalance). Alzheimer’s Disease is one cause of dementia that is neurodegenerative, meaning that symptoms worsen over time.

There are people with Alzheimer’s disease who have very minimal symptoms and are still working, driving, and managing complex tasks. They have the disease, but they do not meet the criteria for dementia.

When should someone be concerned about memory loss?

The signal we watch for is a change from a person’s baseline.

We all have different strengths and weaknesses. I am terrible with navigation, and I am always misplacing things — that has been true my whole life, so it does not worry me. But when someone is experiencing a new symptom that is a change from their own personal “normal,” that is when we recommend discussing with your healthcare provider.

One thing that is clearly abnormal is a loss of episodic memory. Any of us might walk out of a movie unable to recall part of the plot. But if a week later a person has no recollection of going to the theater at all — if they are asking the family when you are all going to see that movie — that deserves an evaluation.

One common symptom in Alzheimer’s Disease is repetitive questioning (asking the same question) or having the conversation Repeatedly. It is often mistaken for hearing loss, and that can be difficult for us to distinguish, too. So, we do recommend ensuring hearing is optimized.

Additionally, hearing loss is itself has recently been identified as a risk factor for cognitive impairment. We are not quite sure of the reason for the association, but nonetheless, we do recommend optimizing hearing.

What is the biggest misconception?

One misconception is that Alzheimer’s Disease progresses quickly and arrives at the very end of a person’s life.

In reality, those proteins are misfolding for 10 to 20 years before they start causing significant symptoms, and now that we can diagnose the disease with early biomarkers, we are identifying it at very early stages. A diagnosis itself does not mean it is time to shut down your activities or plan for imminent decline. In general, Alzheimer’s Disease is a slow, chronically progressive condition, and a diagnosis in itself should not inhibit an individual’s ability to experience joy nor lead a fulfilling life.

What can I do about my risk?

The Lancet Commission has looked at historical data on which conditions raise the risk, and the list includes traumatic brain injury, heavy exposure to alcohol and smoking, high blood pressure, high cholesterol, diabetes, air pollution, hearing loss, physical inactivity, and social isolation.

So, we recommend trying to optimize reversible risk factors, especially early in life, and to stay social and as physically active as possible.

What treatments are available?

Two new infusion therapies target one of the proteins associated with Alzheimer’s Disease, the misfolded “amyloid” protein. The new medications remove misfolded amyloid from the brain. In large randomized clinical trials, the medications have been shown to modestly slow the progression of the disease. These treatments do not reverse the cognitive changes associated with Alzheimer’s Disease, and we do not have a cure. However, the medications can modestly slow progression of disease.

We also have medications that help with symptoms of the disease.

We do advocate for early diagnosis because it gives families knowledge — an explanation for why a person’s strengths and weaknesses have shifted — and it can expedite treatments for symptoms of the disease and also facilitate evaluation for candidacy for the new infusion therapies.

Be empowered to start the conversation

Initiating a discussion about a change in thinking and memory can be rather uncomfortable, and it is common for such a conversation to evoke a defensive reaction. Individuals with a neurodegenerative disease (such as Alzheimer’s Disease) may not be able to recognize changes in their own thinking and memory (a phenomenon called “anosagnosia”), so disagreement about whether cognitive change has occurred is also very common. It may not be a matter of one individual being stubborn or in denial, but more likely that individual does not recognize the changes that have occurred.

We do think about knowledge as being power. If you have noticed a change in yourself or someone you love, we do recommend an initial evaluation to consider potential causes of cognitive change, and to accompany the individual to their appointment to be able to provide the medical provider a third-party perspective on any change that has occurred.

The Alzheimer’s Association is another good place to start, with resources for patients, families and caregivers — including people living with cognitive impairment who do not have Alzheimer’s disease.

Justin Murphy, MD, is a neurologist with Midland Health with fellowship training in behavioral neurology and neuropsychiatry. He earned his medical degree from the University of Virginia School of Medicine and completed his adult neurology residency and fellowship training at the University of Colorado.