Alzheimer's disease (AD) is named after Dr. Alois Alzheimer who discovered the neurodegenerative disorder in 1906 from the brain tissue characterized by abnormal clumps and tangled filaments. The clumps are now known as amyloid plaque and the tangled filaments are called neurofibrillary tangles. They are the hallmarks of AD.
Alzheimer's disease is the most common form of dementia which is characterized by memory loss. Another common form of dementia is vascular dementia, resulting from a series of strokes or changes in the brain’s blood supply.
AD usually begins after age 60, and risk goes up with age. About 3 percent of men and women age 65 to 74 have AD, and nearly half of people older than 85 have the disease. If untreated, the patient will die due to severe brain damage. The time from diagnosis to death varies between 3 to 10 years, depending on age and other health conditions.
At present, no drug can significantly slow the progression of this devastating disease. Between 1990 and 2010, pharmaceutical companies had focused on plaques and tangles, because they were thought to be the main cause of neurotoxicity. Now the plaques and tangles are believed to have beneficial effects. The real cause of AD is just beginning to emerge, which may point to new direction for the development of effective drugs.