Читать книгу The Alzheimer's Epidemic - Danton O'Day - Страница 29

If Alzheimer’s disease does progress, it moves from these mild cognitive impairment stages to dementia. The progression of Alzheimer’s disease to dementia is associated with a number of emotional changes, many of which are observed with mild cognitive impairment but now are seen with greater frequency and with heightened expression. With dementia, the person will typically experience one or more of the following: anxiety, various fears (e.g., abandonment), despair, anger and depression. They may also show compulsive behaviors and tend to suffer from hypochondria.

Delusions are also a common characteristic of Alzheimer’s disease dementia. The simplest definition of delusions is that they are false beliefs, impressions or opinions. Typically the caregiver will have trouble convincing the Alzheimer’s sufferer that their delusions are unfounded. Since delusions occur in about 31% of all cases, they are of serious concern to family members and caregivers. The presence of delusions in the Alzheimer’s individual is often a sign of worsening behavior that likely will lead to early admission to a long-term care residence as well as increased caregiving. So there are many reasons to understand the signs and symptoms of delusions. This is typically done through the administration of psychological tests. These are carried out in conjunction with other questionnaires that assess behavior, quality of life as well as the ability to function in the real world. Questionnaires can also be given to reveal the burden that is put on caregivers who are responsible for looking after those suffering from delusional behaviors.

The accumulated research reveals that delusions arise due to the deterioration of the frontal lobe of the brain. Poor frontal lobe functioning is also linked to impaired activities in the Alzheimer’s individual’s daily life. CT (Computerized Tomography) scans show more lesions in frontal lobe white matter in delusional sufferers compared to normal individuals. PET (Positron Emission Tomography) studies show a reduced uptake of glucose in the frontal lobe of individuals with delusional behavior caused by Alzheimer’s disease. The sugar glucose is an energy source for cells and a reduced uptake by neurons signals their decreased energy needs. This in turn indicates that these cells are less functional than normal brain cells. As if this weren’t enough, delusional Alzheimer’s individuals also show increased levels of amyloid plaques in their frontal lobes. These and other aspects of the Alzheimer’s brain are discussed in Chapter 4 as well as elsewhere throughout the book.

With dementia, individuals progressively lose their ability to respond to the world around them. They become unable to perform the normal activities of daily life or to simply carry on a conversation. They often fail to recognize loved ones or remember who they are. This loss of cognitive awareness likely underlies many of the symptoms of the dementia stage of Alzheimer’s disease where increased levels of panic and anxiety are not uncommon. Hypochondria is common in about 30% of dementia individuals. So too are increases in obsessive behavior, paranoia and depression. One study revealed that around 40% of dementia sufferers experienced one or more of these behavioral symptoms. Around 13% of individuals ultimately become antisocial while over 20% exhibit schizoid behavior. Some can become violent. Of all of these behaviors, schizoid and paranoid tendencies increase the greatest degree in the progression from MCI to dementia. Family caregivers usually are no longer able to care for the Alzheimer’s sufferer by the dementia stage. Full-time care is required which often is only available in a long-term care home.

It is critical to reiterate that the severity of MCI is not a 100% predictor of progression to dementia. Not all MCI individuals will suffer from dementia. It has been estimated that about 15% of people with MCI progress to the dementia stage per year. In one study, 25% of the MCI group had not progressed to dementia even after 10 years. Currently, there is no way to determine which MCI individual will progress to full-fledged dementia.