Alzheimer’s Disease

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 of daily living. In most people with Alzheimer’s disease, symptoms first appear after age 60.

In persons older than 65, Alzheimer’s disease is the most common cause of dementia – the loss of cognitive functioning that impairs thinking, remembering, reasoning and behavior.

Alzheimer’s disease may be triggered by many factors, and its incidence increases with age. Less than 10% of cases are inherited, and usually occur between ages 30 and 60. (1)

According to the National Institute on Aging, the FDA has approved four medications for Alzheimer's disease. Donepezil (Aricept®), rivastigmine (Exelon®), or galantamine (Razadyne®) are used to treat mild to moderate Alzheimer's disease (donepezil can be used for severe Alzheimer's disease as well). Memantine (Namenda®) is used to treat moderate to severe Alzheimer's disease. (2)

These drugs work by regulating neurotransmitters, the chemicals that transmit messages between neurons. They may help maintain thinking, memory, and speaking skills, and may help with certain behavioral problems. However, these drugs don’t change the underlying disease process, are effective for some but not all people, and may help only for a limited time.

The disease takes its name from Dr. Alois Alzheimer who, in 1906, 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. After she died, he examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles). Plaques and tangles in the brain are two of the main features of Alzheimer’s disease. The third is the loss of connections between nerve cells (neurons) in the brain.


1. Alzheimer’s Foundation of America. About Alzheimer’s: Definition of Alzheimer’s. Accessed Jan. 14, 2013.

2. National Institute on Aging Alzheimer’s Disease Education and Referral Center. Alzheimer’s Disease: Treatment. (accessed Jan. 14, 2013)

Reviewed Feb. 5, 2013
Bomin Sun, MD
Member, International Neuromodulation Society
Department of Stereotactic and Functional Neurosurgery, Shanghai Jiaotong University School of Medicine Ruijin Hospital, Shanghai, China

Last Updated on Sunday, November 21, 2021 08:15 PM