Alzheimer’s disease (AD) is defined under DSM-IV criteria as a progressive neurodegenerative disorder and is characterized by the development of multiple cognitive deficits (Cummings, 2001; Cummings & Khachaturian, 1996). AD usually happens with increasing age, especially over the age of 65 as well as genetics related (DeKosky, 2001; Blass & Poirier, 1996). The incidence of getting AD in the population is about 1% to 4% per year (DeKosky, 2001). The diagnosis of AD is complex and it may require many visits to different specialists over several months before the diagnosis can be confirmed (Sims, Odle & Davidson, 2009). The few common laboratory test that is able to indicate the present of AD are blood and urine test, brain tomography (MRI), positron emission tomography (SPECT) scans and tests of the brain’s electrical activity (electroencephalographs or ECGs) (Sims, Odle & Davidson, 2009). Even so AD cannot be diagnosed conclusively until an autopsy examination is done for the examination of the brain for plaques and neurofibrillary tangles (Sims, Odle & Davidson, 2009). AD can be categorised into two main categories. The first category is the deficits in the metabolism of neurotransmitter that is acetylcholine (ACh) which is required for the short memory function (DeKosky, 2001). The second category is the structural changes in the brain (DeKosky, 2001). It can be either structural loss or alteration of the structure that affects the cortex of the brain that is responsible for the short term memory (DeKosky, 2001).
Regardless which category AD patients are suffering, they would display certain characteristics that are indicative of AD. They are