The Brain is the most mysterious organ in the human body. Even the slightest change in its functional anatomy and physiology results in serious manifestations. The statistics clearly shows that almost 25 million people suffer from dementia worldwide (Ballard et al., 2011). Dementia has many forms out of which Alzheimer’s disease is the most common form. This is one of the most serious and progressive diseases affecting the human brain. Mostly, it is found in people of age over 65 years.
The population affected in this disease includes persons above the age of 65 years (5% to 15%). The half of the deaths due to this disease occurs in persons of 85 years of age and above. Women are more susceptible to this disease than men. The statistics show that 40 cases are reported every hour. (Cummings & Cole, 2002).
Causes of Alzheimer’s disease are still unknown. Many hypotheses have been proposed which include Genetic reasons, deposition of excess amyloid, cholinergic hypothesis or tau protein hypothesis. Cholinergic hypotheses states that Alzheimer’s disease is caused by decrease in synthesis of neurotransmitter acetylcholine.
There is no cure for this disease till now. Only palliative treatment is available, which includes administration of five medications. Four of the five drugs are Acetylcholinsterase Inhibitors which are tacrine, galantamine, donepezil & rivastigmine. The fifth drug is Memantine, which is an N-Methyl-D-aspartate (NMDAR) receptor antagonist. But no drug has been able to completely delay or halt the progression of the disease. In Alzheimer’s disease, there is reduction in activity of cholinergic neurons and thus, Acetylcholinsterase inhibitors are administered to reduce the breakdown of Acetylcholine (Ach) and therefore help in compensating acetylcholine lost. Anti-psychotic drugs are also used to decrease episodes of aggression and psychosis but these drugs are responsible for causing serious adverse effects like stroke and movement difficulties.
If Alzheimer’s disease goes unchecked without any symptomatic treatment, then, it progresses even faster and eventually leads to death. The early stages of this disease are not easy to diagnose. The life expectancy of such patients is decreased and after diagnosis, the patients live up to seven years. Studies have shown that prognosis is much poorer in males than in females. The most common causes of death in this disease are Pneumonia and Dehydration and not the disease itself.
- Alzheimer's Association (2007). Alzheimer's disease facts and figures. Retrieved June 7, 2014, from http://www.alz.org/nationa/documents/report_alzfactsfigures2007.pdf
- Alzheimer's Association (2014). Treatments for Alzheimer's disease. Retrieved June 7, 2014, from http://www.alz.org/alzheimers_disease_treatments.asp
- Cummings, J. L., & Cole, G. (2002). Alzheimer disease. The Journal of the American Medical Association, 287(18), 2335-2338.
- Marieb, E. N., & Hoehn, K. (2010). Human anatomy and physiology (8th ed.). London, UK: Pearsons Education.
- National Institutes of Health (2012). Alzheimer's disease fact sheet. Retrieved from http://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-fact-sheet