Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia among older people.

Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities.

AD begins slowly. It first involves the parts of the brain that control thought, memory and language. People with AD may have trouble remembering things that happened recently or names of people they know. A related problem, mild cognitive impairment (MCI), causes more memory problems than normal for people of the same age. Many, but not all, people with MCI will develop AD.

In AD, over time, symptoms get worse. People may not recognize family members. They may have trouble speaking, reading or writing. They may forget how to brush their teeth or comb their hair. Later on, they may become anxious or aggressive, or wander away from home. Eventually, they need total care. This can cause great stress for family members who must care for them.

AD usually begins after age 60. The risk goes up as you get older. Your risk is also higher if a family member has had the disease.

No treatment can stop the disease. However, some drugs may help keep symptoms from getting worse for a limited time.

There are no direct causes for Alzheimer’s because it is a genetic disease. There are some possible explanations for this below:

Most people with Alzheimer’s disease have the late-onset form of the disease, in which symptoms become apparent in their mid-60s.The apolipoprotein E (APOE) gene is involved in late-onset Alzheimer’s. However, carrying the APOE ε4 form of the gene does not mean that a person will definitely develop Alzheimer’s disease, and people with no APOE ε4 may also develop the disease.

Also, scientists have identified a number of regions of interest in an organism’s complete set of DNA that may increase a person’s risk for late-onset Alzheimer’s to varying degrees.

Early-onset Alzheimer’s disease occurs in people age 30 to 60 and represents less than 5 percent of all people with Alzheimer’s. Most cases are caused by an inherited change in one of three genes, resulting in a type known as early-onset familial Alzheimer’s disease, or FAD. For others, the disease appears to develop without any specific, known cause, much as it does for people with late-onset disease.

10 warning signs of Alzheimer’s:
  • Memory Loss that disrupts daily life
  • Challenges in planning of solving problems
  • Difficulty completing familiar tasks at home, at work or at leisure
  • Confusion with time or place
  • Trouble understanding visual  images and spatial relationships
  • New problems with words in speaking or writing
  • Misplacing things and losing the ability to retrace steps
  • Decreased or poor judgment
  • Withdrawal from work or social activities
  • Changes in mood and personality
To diagnose Alzheimer’s, doctors may:
  • Ask the person and a family member or friend questions about overall health, past medical problems, ability to carry out daily activities, and changes in behavior and personality
  • Conduct tests of memory, problem solving, attention, counting, and language
  • Carry out standard medical tests, such as blood and urine tests, to identify other possible causes of the problem
  • Perform brain scans, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET), to rule out other possible causes for symptoms.

These tests may be repeated to give doctors information about how the person’s memory and other cognitive functions are changing over time. Tests can also help diagnose other causes of memory problems, such as mild cognitive impairment and vascular dementia. Alzheimer’s disease can be definitely diagnosed only after death, by linking clinical measures with an examination of brain tissue in an autopsy.

Currently there are no medicines that can slow the progression of AD. However, four FDA-approved medications are used to treat AD symptoms. These drugs help individuals carry out the activities of daily living by maintaining thinking, memory, or speaking skills. They can also help with some of the behavioral and personality changes associated with AD. However, they will not stop or reverse AD and appear to help individuals for only a few months to a few years. Donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne) are prescribed to treat mild to moderate AD symptoms. Donepezil was recently approved to treat severe AD as well. The newest AD medication is memantine (Namenda), which is prescribed to treat moderate to severe AD symptoms.

In very few families, people develop AD in their 30s, 40s, and 50s. This is known as "early onset" AD. These individuals have a mutation in one of three different inherited genes that causes the disease to begin at an earlier age. More than 90 percent of AD develops in people older than 65. This form of AD is called "late-onset" AD, and its development and pattern of damage in the brain is similar to that of early-onset AD. The course of this disease varies from person to person, as does the rate of decline. In most people with AD, symptoms first appear after age 65.

We don't yet completely understand the causes of late-onset AD, but they probably include genetic, environmental, and lifestyle factors. Although the risk of developing AD increases with age, AD and dementia symptoms are not a part of normal aging. There are also some forms of dementia that aren't related to brain diseases such as AD, but are caused by systemic abnormalities such as metabolic syndrome, in which the combination of high blood pressure, high cholesterol, and diabetes causes confusion and memory loss.