Alzheimer's disease is a neurodegenerative disease, meaning it attacks neurons in the brain. Neurons are the areas of the brain that allow the transmission of chemical messages, or neurotransmitters. These neurons are necessary for connections with other nerve cells, and without them, neurons eventually die. Alzheimer's disease is a form and the most common cause of dementia or loss of intellectual capacity and personality. ("Dementia.") Alzheimer's disease, or AD, is not a normal part of aging, although the risk of developing the disease increases with age. The onset behavior of the disease does not normally appear until the age of sixty. Although symptoms appearing before the age of sixty have occurred, they are less common and tend to be hereditary; these early onsets also tend to progress more quickly. ("Alzheimer's Disease") AD is one of the ten leading causes of death in America. In fact, it is estimated that as many as 5.1 million people in the United States may suffer from Alzheimer's disease; this number is steadily increasing with the growing elderly population. ("About Alzheimer's Disease") Over the past forty years, Alzheimer's disease has become a prominent topic within the medical and non-medical communities, affecting lives and families; which gives us a reason to deepen our understanding of the brain. Alzheimer's disease has been known since the turn of the century, but was not a widespread concern until the 1970s. In 1907, Alois Alzheimer, a German physician, documented the case of a fifty-one-year-old woman suffering severe cognitive impairment. She showed difficulties in areas such as memory, language and social interactions. (Reger 1) After his death, Alzheimer performed a brain autopsy using silver staining techniques. This allowed him to... middle of paper ......int."Dementia". Dictionary.com full version. Random House, Inc. May 2. 2015. Reger, Beth. “Alzheimer's disease: a brief history and current avenues of research. » Journal of young researchers: undergraduate, peer-reviewed scientific journal 6.2 (2002): 1-3. Internet. April 29, 2015. Robinson, Lawrence, Joanna Saisan and Jeanne Segal. "Alzheimer's disease: signs, symptoms and stages of Alzheimer's disease." Helpguide.org: Ad-free articles from experts help give you knowledge, support and hope. HelpGuide, March 2011. Web. April 29, 2015. “Studies show a link between Alzheimer's disease, Down syndrome and atherosclerosis. » ScienceDaily, January 15, 2010. Web. May 3, 2015. Wattamwar, Pandurang and P. Mathuranath. “An Overview of Alzheimer’s Disease Biomarkers.” Annals of the Indian Academy of Neurology 13.6 (2010): 116. ProQuest Research Library. Internet. April 12 2015.