Chapter 1

An Overview of Dementia and Alzheimer’s Disease

In This Chapter

Seeing the relationship between dementia and Alzheimer’s disease

Understanding the link between age and dementia

Recognizing the four main types of dementia

If you’re reading a book about dementia, you first need to understand what the term means. People have a whole lot of different ideas about what sort of condition the word dementia suggests. For some, it’s the diagnostic label you give to people who keep having “senior moments” and regularly forget names and where they put their eyeglasses. To others, it refers to people who are old and confused and spend all day shouting at the television and letting their friends and neighbors know exactly what they think of them.

Although some of these symptoms clearly can be part of the picture of dementia, neither of the people described actually fit the diagnosis. The first is probably just forgetful but otherwise well, and the second may simply be grumpy and bad-tempered. Dementia has a very clear definition, and the diagnosis should never be made lightly.

This chapter looks in detail at what dementia is and what it certainly is not and serves a jumping-off point for what you can expect to face when your loved one receives a dementia or Alzheimer’s disease (AD) diagnosis.

Defining the Relationship between Dementia and Alzheimer’s Disease

This section explains what dementia is and isn’t and then does the same for Alzheimer’s. As you read this text, keep in mind the relationship between dementia and AD. In many cases, what we write about dementia applies to AD, but what we write about AD may not apply to dementia in all of its forms.

Understanding what dementia is

Dementia is a general term for a decline in mental ability (including impaired memory, language, reasoning, judgment, visuospatial skills, and orientation) severe enough to interfere with daily life. Think of dementia as a big general category like the word “building.” Just as there are many specific types of buildings (stores, houses, cabins, skyscrapers, factories, and so on), there are many specific forms of dementia. AD is the most common cause of dementia making up about 60 percent of dementia cases. We discuss other forms of dementia later in this chapter.

Dementia isn’t a single entity. Multiple different medical conditions that affect normal brain functioning are causes of dementia.

The World Health Organization (WHO) defines dementia thus:

[A] syndrome — usually of a chronic or progressive nature — in which there is deterioration in cognitive function (i.e. the ability to process thought) beyond what might be expected from normal aging. It affects memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgment. Consciousness is not affected. The impairment in cognitive function is commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behavior, or motivation.

This definition, however, still contains a fair amount of medical jargon. So we try to come up with a simpler, but still accurate, version by considering each of the key terms used by the WHO:

• Syndrome: This word describes the symptoms that together are characteristic of a particular medical condition. People with the condition have most of these symptoms but don’t have to show all of them to receive the diagnosis. Thus with dementia, one person may have poor memory and language but still have judgment enough to not walk out into a busy road, whereas another may have problems with both memory and judgment but have no changes in language skills.
• Chronic and progressive: These terms mean that the condition is on-going long term and gets steadily worse with time. Many people think that the word chronic means that something is severe. Although dementia may be severe for some people, it’s mild in others; chronic here means long-lasting.
• Consciousness: Used in relation to dementia, this word takes on both of its meanings. People with dementia are both awake (as opposed to unconscious) and mentally aware of their surroundings, although what’s going on around them is confusing to them.

A number of diseases of the brain that lead to a collection of progressively worsening symptoms affecting a person’s thought processes, mood, and behavior can cause dementia; eventually, the person loses the ability to carry out the basic tasks of daily living.

In the “Realizing that Dementia Doesn’t Just Mean Alzheimer’s” section later in this chapter, we explain the four main types of dementia to help you understand the bigger picture of memory disorders.

Grasping what dementia is not

In the past, dementia has been referred to as “senility” or “senile dementia”. This terminology reflects the previously common but incorrect belief that serious mental decline is a normal part of aging. Many myths and misunderstandings circulate about dementia. And to get a grasp of what dementia actually is, it’s important to have a clear idea about what it certainly isn’t. So here’s a selection of some of the most common misconceptions to help sort fact from fiction.

• All old people get dementia. Although the chances of developing dementia do increase as people get older, it’s not a normal part of the aging process. In the United States, 1 in 9 people older than 65 and 1 in 3 older than 85 suffer from it.
• Dementia is the same as Alzheimer’s disease. Alzheimer’s disease is just one of a number of brain diseases that lead to dementia.
• Memory loss equals dementia. Dementia does affect memory, but for someone to be diagnosed with the condition, he needs to show many other more complex symptoms rather than simply poor memory alone.
• Everyone with dementia becomes aggressive. Even though some people with dementia can become agitated, aggression isn’t a universal feature of dementia and is usually triggered by the way someone is treated or communicated with rather than being a symptom of the dementia alone.
• A diagnosis of dementia means a person’s life is over. Despite the fact that the condition is chronic and progressive, many medical, social, and psychological treatments and strategies are available to help make life as fulfilling as possible for someone with dementia, for many years.
• Everyone with dementia ends up in a nursing home. Although one-third of people with dementia do eventually need this level of intense care in the later stages of their condition, many people are able to access enough help and support to stay in their own homes.
• My aunt has dementia, so I’m going to get it too. Some forms of dementia do have a genetic component and may run in families, but these are in the minority. For most people, it doesn’t follow that because a relative has dementia, they’ll get it too. And contrary to what one patient thought, you can’t catch it from your aunt either.

Understanding what Alzheimer’s disease is

As previously stated, AD is a form of dementia. Although all AD patients have dementia, not all dementia patients have AD. The Alzheimer’s Association defines Alzheimer’s disease as “an irreversible, progressive brain disease that slowly destroys memory and thinking skills, eventually even the ability to carry out the simplest tasks.” AD is a fatal disease, ending inevitably in death.

Alzheimer’s disease was named after a German physician, Alois Alzheimer, who first identified the condition in 1906 when he performed an autopsy on the brain of a woman who’d been suffering severe memory loss and confusion for years. He observed microscopic amyloid plaques and neurofibrillary tangles in the woman’s brain tissue under a microscope. He then correctly hypothesized that these abnormal deposits were responsible for the patient’s loss of memory and other cognitive problems. To this day, AD can only be diagnosed with 100 percent accuracy through an autopsy that reveals the presence of the characteristic plaques and tangles in the brain. However, a comprehensive examination and good work-up do provide a reliable diagnosis with greater than 90 percent accuracy.

Abnormal deposits of specific proteins inside the brain disrupt normal brain function and cause the cognitive and functional problems typically associated with AD. Eventually, as these deposits spread throughout the brain, brain tissue starts dying, which leads to further cognitive impairment. The resulting brain shrinkage can be seen in CT scans and MRI scans. Current research is focused on trying to determine what causes these deposits and is looking for ways to prevent or reverse them before they cause permanent brain damage.

Seeing what AD is not

The preceding section, “Defining the Relationship between Dementia and Alzheimer’s Disease” talks about what AD is. Now allow us to go over what it isn’t. AD is not

• Curable
• Contagious
• A natural part of the aging process
• Something you get from using deodorant or cooking in aluminum pans
• Inevitable if you live long...