By the final stage, plaques and tangles have spread throughout the brain, and brain tissue has shrunk significantly. People with severe Alzheimer’s have extreme difficulty communicating and are completely dependent on others for their care. Near the end, the person may be in bed most or all of the time as the body shuts down.
In this stage, damage occurs in areas of the brain that control language, reasoning, sensory processing, and conscious thought. Memory loss and confusion grow worse, and people begin to have problems recognizing family and friends. They may be unable to learn new things, carry out tasks that involve multiple steps (such as getting dressed), or cope with new situations. They may have other behavioral changes taking place, such as increased agitation or delusions.
As Alzheimer’s disease progresses, memory loss worsens, and changes in other cognitive abilities are evident. Problems can include, for example, getting lost, trouble handling money or paying bills, repeating questions, taking longer to complete normal daily tasks, using poor judgment, becoming socially withdrawn and having some mood and personality changes. People often are diagnosed in this stage.
Although we still don’t exactly know how the Alzheimer’s disease process begins, experts now believe that damage to the brain starts a decade or more before problems become evident. During the preclinical stage of Alzheimer’s disease, people are free of symptoms but toxic changes are taking place in the brain. Abnormal deposits of proteins form amyloid plaques and tau tangles throughout the brain, and once-healthy neurons begin to work less efficiently. As a result of these accumulations of plaques and tangles, neurons lose their ability to function and communicate with each other, and eventually they die.
Memory problems are typically one of the first warning signs of cognitive loss, possibly due to the development of Alzheimer’s disease. Difficulty finding words in conversations, misplacing objects and attentional changes are all considered early warning signs or symptoms possibly. Some people with memory problems have a condition called mild cognitive impairment (MCI). People with this condition have more memory problems than normal for people their age, but their symptoms are not as severe as those seen in people with Alzheimer’s disease. The ability of people with MCI to perform normal daily activities is not significantly impaired, only mildly different from their previous level of functioning. Approximately 15% of the individuals with MCI go on to develop Alzheimer’s on an annual basis.
Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and thinking skills, and eventually even the ability to carry out the simplest tasks. In most people with Alzheimer’s, symptoms first appear after age 65. In Early onset cases the symptoms can appear in the 40’s and 50’s. Estimates vary, but experts suggest that as many as 5.5 million Americans may have Alzheimer’s disease. The older one gets the greater the chance of developing Alzheimer’s disease.
There are many types of dementia, all caused by a different process occurring with the brain. Alzheimer’s disease is the most common cause of dementia among older people accounting upwards of 80% of the cases over the age of 65. Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities, to such an extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living.
Alzheimer’s disease is named after Dr. Alois Alzheimer. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. Her symptoms included memory loss, language problems, and unpredictable behavior. Upon her death Dr. Alzheimer examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles). The plaques are made up of beta amyloid fibrils that ‘clump’ in the brain and ultimately kill neurons. The tangles occur when the tau protein molecule destabalizes within the neuron itself, become ‘tangled’ and also contribute to the progression of the disease.
