What is Alzheimer’s disease?

Alzheimer’s disease, the sixth leading cause of death in the U.S., is a progressive brain disorder that causes problems with thinking, memory, and behavior. It is the leading cause of dementia, the general term used to describe the decline of memory and cognitive abilities serious enough to interfere with normal daily life. 

Named after Dr. Alois Alzheimer who first described changes in a deceased woman’s brain tissue in 1907. She experienced symptoms such as memory loss and language problems. Alzheimer discovered abnormal amyloid plaques and tangled bundles of fibers (often called tau tangles) when he examined her brain. 

Today there are an estimated 5.5 million people age 65 and older in the United States suffering from Alzheimer’s disease as well as another estimated 200 thousand under the age of 65 with early onset Alzheimer’s.  There is currently no cure and that number will continue to climb without the development for a treatment.

What causes Alzheimer’s disease?

Researchers believe there are many factors that influence the development of Alzheimer’s disease. One of the best-known risk factors is age. On average, 1 in every 10 individuals age 65 and older have the disease. The older the individual, the higher the chance they will have Alzheimer’s. It is also widely thought that the accumulation of plaques and development of tangles within the brain play an essential role. 

Since discovering the disease, researchers have heavily studied the roles of these plaques and tangles believing that they damage and kill vital cells. Despite the study of these factors, a single cause of Alzheimer’s has not been identified. Other factors such as changes in function of blood vessels and activity of immune cells and inflammation are being studied more closely to understand their role in the disease process. Researchers are also studying how things like lifestyle and environment can influence the disease. 

Understanding the impact cardiovascular health has on cognitive function may shed light on how lifestyle and diet changes could be used to influence neurodegeneration. Numerous clinical studies and trials are being conducted to evaluate many of these different factors and their roles in Alzheimer’s disease.

What are the symptoms of Alzheimer’s?

Because Alzheimer’s disease is a progressive disorder, symptoms often take years to manifest. It’s believed that changes in the brain begins more than a decade prior to the first appearance of symptoms. Early symptoms vary from person to person but generally involve memory or other cognitive abilities. Examples include difficulty remembering recent activities or events and taking longer to complete normal daily tasks. 

The symptoms of Alzheimer’s also vary depending on the stage of the disease. Many of the symptoms of late-stage Alzheimer’s may be more severe version of early-stage symptoms. Some, however, represent new symptoms including inability to perform basic tasks like feeding and hygiene, and, in very late stages, even basic motor skills such as walking may be affected.

Symptoms of Alzheimer’s include:

• Memory loss
• Confusion
• Shortened attention span
• Personality changes
• Trouble recognizing people
• Loss of bladder and bowel control
• Inability to speak or highly impaired speaking
• Trouble swallowing

What are the stages of Alzheimer’s disease?

Because Alzheimer’s disease is a progressive disorder, not all the symptoms manifest at once. Dr. Barry Reisberg of New York University has developed a system that breaks the progression of Alzheimer’s disease into seven stages. This system has become the commonly used by a number of healthcare providers. It’s important to note that symptoms do not always adhere to the system and can vary in their onset.

Stage 1: No impairment/Normal behavior

During this stage, individuals are considered mentally healthy. They show no signs of cognitive decline and their behavior is consistent.

Stage 2: Very mild decline

Sometimes called normal aged forgetfulness, in stage two people start to experience declining speeds in their memory. They may have trouble concentrating or finding the right word when speaking.

Stage 3: Mild cognitive impairment (MCI)

At this stage, subtle deficits in cognitive begin to manifest. Though noticeable, cognitive function has not yet declined to the point where it impedes an individual’s day-to-day life. Those with MCI may notice learning new tasks is more difficult, have trouble remembering names, and struggle with organizing and planning. Losing personal possessions more frequently is a common symptom during this stage. Mild cognitive impairment can be considered the bridge between unimpaired cognitive function and more severe forms of dementia. 

Stage 4: Mild Alzheimer’s disease

Individuals can often be diagnosed with Alzheimer’s disease with relative accuracy during this stage. It’s during this stage that one’s cognitive function has declined to the point in which performing activities associated with daily life are difficult to manage. 

For example, previously normal activities such as shopping, preparing meals, and managing finances may no longer be consistently handled by the individual. It’s during this stage that symptoms of impairment become much more noticeable. Some during this stage are still able to live independently in community settings depending on the severity of their symptoms.

Stage 5: Moderate Alzheimer’s disease

The challenges with daily activities become more pronounced during this stage. Individuals often suffer from significant confusion. Common observable challenges include recalling simple details such as phone numbers, addresses, or schools attended. Dressing appropriately often becomes an issue as well. Individuals can have trouble dressing for the weather or may not change clothes until guided to do so.

Stage 6: Moderately severe Alzheimer’s disease

At this stage, people lose the ability to perform tasks associated with daily life. Cognitively, they can lose the ability to recognize people’s faces, are unable to remember personal details, and are easily confused by their surroundings and environment. It’s not uncommon for major personality changes to occur. 

People in this stage of Alzheimer’s disease often need constant supervision or require professional care. Wandering can be particularly dangerous. Functionally, those in this stage can have trouble controlling bladder and bowel functions, operating things such as showers, and putting on clothes.

Stage 7: Severe Alzheimer’s disease

In the final stage of Alzheimer’s disease, cognitive decline is at its worst. Individuals at this point require nonstop care. Speech is often limited, sometimes to just a few intelligible words. The loss of physical control can be so severe that they are unable to sit up on their own and risk falling over unless supported. 

This can accompany the loss of control of the face and neck resulting in the inability to make facial expressions or hold the head upright. In some extreme cases, some even lose the ability to swallow. While some may be able to be sustained during this stage, prolonged life in this stage is not common.

Early-onset Alzheimer’s disease

Not all instances of Alzheimer’s disease begin when people are 65 and older. A small percentage of people with Alzheimer’s will experience early onset, starting when they are in their 40’s or 50’s, but potentially starting earlier in rare cases. This is what’s considered early-onset Alzheimer’s disease. 

For most people with early-onset Alzheimer’s the symptoms are similar to those experienced by individuals afflicted with the disease later in life. It’s important to monitor early signs and effectively communicate with primary care providers to rule out other causes.

Alzheimer’s Treatment

Alzheimer’s disease is incredibly complex and there is currently no cure. Treatments are frequently aimed at helping people maintain mental function, manage behavioral changes, and ease symptoms. Several prescription drugs have been shown to most effective for early and mid-stage Alzheimer’s patients. 

These medications, called cholinesterase inhibitors, work to prevent the breakdown of acetylcholine, a chemical in the brain believed to be important for memory and thinking. Razadyne (galantamine), Exelon (rivastigmine), and Aricept (donepezil) are examples of cholinesterase inhibitors regularly prescribed for treating Alzheimer’s. 

For those with moderate to severe Alzheimer’s, an N-methyl D-aspartate (NMDA) antagonist called Namenda (memantine) can be prescribed. It’s believed to work by regulating glutamate, a brain chemical that may lead to brain cell death when produced in excessive amounts. The medication may help someone in with later-stage Alzheimer’s extend the amount of time they’re able to perform normal functions such as using the bathroom independently. 

Behavioral problems commonly arise from Alzheimer’s disease and include anxiety, depression, and sleeplessness. Antidepressants like Zoloft (sertraline) and Celexa (citalopram) can be prescribed to help treat aggression, depression, and anxiety. In some cases, a doctor may prescribe sleep aids or anti-anxiety medications, but only after other safer alternatives have been explored. While current medications can help treat some symptoms of Alzheimer’s, it’s important to understand that none of these medications prevent the progression of the underlying disease.

Alzheimer’s Prevention

As people age, many fear developing Alzheimer’s disease or a related dementing illness. The fear of genetic predisposition can compound these feelings. Despite the many studies conducted by researchers worldwide, nothing has been proven to prevent the onset of Alzheimer’s disease. Some promising strategies however are being identified. 

Researchers are learning that changes in the brain typically begin years before people start experiencing symptoms. Finding the cause of these early changes could allow delaying or even preventing dementia symptoms, whether through drugs or lifestyle changes. The Emory Healthy Brain Study, a sub study of the Emory Healthy Aging Study, is working to identify predictive biomarkers in in younger healthy participants that will allow researchers to more effectively determine the cause and predict the development of the disease. 

To learn more about how you can support this research please visit, https://healthyaging.emory.edu/ehbs/.