During the autopsy the doctor noted dense deposits of neuritic plaques surrounding nerve cells and twisted bands of nerve fibers inside the cells. The presence of plaques and tangles during a brain autopsy is now taken as a definitive diagnosis of the condition. There have been several additional researches that have been carried out by scientist around the world since the discovery of the disease. In the 1960s researchers found connectivity between the cognitive decline and the number of plaques and tangles present in the brain. Since the 1970s scientists have made major discoveries pertaining to the complex functioning of the nerve cells in these patients and also with increasing developments in the field of genetics, genes responsible for susceptibility to this disease both in the early stages and later in life have also been unraveled. Apart from the genetic factors other lifestyle related and environmental risk factors are also being widely being explored (A History, 2009; Alzheimer’s disease, 2010).
Alzheimer’s is a progressive disease and before the symptoms are noticed sufficient damage to the brain would have already taken place. Studies reveal that this damage could occur anywhere between 10 to 20 years before the onset of the clinical signs and symptoms. Beginning with the development of tangles within the entorhinal cortex and plaques in other regions of the brain, the disease affects the functioning of neurons that eventually results in lost communication between the brain cells. When such damage occurs within the hippocampus region of the brain as the disease progresses, it affects the memory and processing skills of the individual (Alzheimer’s disease, 2010). Thus most prominent early sign of the disease is memory loss (Alzheimer’s disease, 2010; Alzheimer’s symptoms, 2009; Symptoms, 2009). Other common early symptoms include confusion, attention disorders, personality changes, difficulty with languages