Alzheimer's Disease

Alzheimer's Information & Treatment Introduction

Alzheimer's disease is a progressive, neurodegenerative disease characterized in the brain by abnormal clumps (amyloid plaques) and tangled bundles of fibers (neurofibrillary tangles) composed of misplaced proteins. Age is the most important risk factor for Alzheimer's disease. The number of people with the disease doubles every 5 years beyond age 65. Three genes have been discovered that cause early onset (or family) Alzheimer's. Other genetic mutations that cause excessive accumulation of amyloid protein are associated with age-related (sporadic) Alzheimer's.

Symptoms of Alzheimer's disease include memory loss, language deterioration, impaired ability to mentally manipulate visual information, poor judgment, confusion, restlessness, and mood swings. Eventually Alzheimer's destroys cognition, personality, and the ability to function. The early symptoms of Alzheimer's disease, which include forgetfulness and loss of concentration, are often missed because they resemble natural signs of aging.

Symptoms of Alzheimer's Disease

Alzheimer's disease is characterized by the development of multiple cognitive deficits manifested by:

• Memory impairment (impaired ability to learn new information or to recall previously learned information)
• And one (or more) of the following cognitive disturbances:
  • Deterioration of language may be manifested by difficulty producing the names of individuals and objects (aphasia)
  • An impaired ability to carry out motor activities (such as combing their hair) despite intact motor abilities, sensory function and comprehension of the required task (apraxia)
  • A failure to recognize or identify objects despite intact sensory function (agnosia)
  • A disturbance in executive functioning (e.g., planning, organizing, sequencing, abstracting)

The cognitive deficits above each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning. The course is characterized by gradual onset and continuing cognitive decline. The deficits do not occur exclusively during the course of a delirium.
The cognitive deficits above are not due to any of the following:

• Other central nervous system conditions that cause progressive deficits in memory and cognition (e.g., cerebrovascular disease, Parkinson's disease, Huntington's disease, subdural hematoma, normal-pressure hydrocephalus, brain tumor)
• Systemic conditions that are known to cause dementia (e.g., hypothyroidism, vitamin B-12 or folic acid deficiency, niacin deficiency, hypercalcemia, neurosyphilis, HIV infection)
• substance-induced conditions 

Causes of Alzheimer's

Scientists do not yet fully understand what causes Alzheimer's disease. There probably is not one single cause, but several factors that affect each person differently. Age is the most important known risk factor for Alzheimer's disease. The number of people with the disease doubles every 5 years beyond age 65.
Family history is another risk factor. Scientists believe that genetics may play a role in many Alzheimer's disease cases. For example, familial Alzheimer's disease, a rare form of Alzheimer's disease that usually occurs between the ages of 30 and 60, can be inherited. However, in the more common form of Alzheimer's disease, which occurs later in life, no obvious family pattern is seen. One risk factor for this type of Alzheimer's disease is a protein called apolipoprotein E (apoE).
Everyone has apoE, which helps carry cholesterol in the blood. The apoE gene has three forms. One seems to protect a person from Alzheimer's disease, and another seems to make a person more likely to develop the disease. Other genes that increase the risk of Alzheimer's disease or that protect against Alzheimer's disease probably remain to be discovered.
Scientists still need to learn a lot more about what causes Alzheimer's disease. In addition to genetics and apoE, they are studying education, diet, environment, and viruses to learn what role they might play in the development of this disease.