Alzheimer’s Disease – An Update

Introduction:

Alzheimer’s (AD) disease is a progressive and fatal neurodegenerative disorder manifested by cognitive and memory deterioration, progressive impairment of activities of daily living and a variety of
neuropsychiatric symptoms and behavioral disturbances1.
This incurable, degenerative, and terminal disease was first described by German psychiatrist and
neuropathologist Alois Alzheimer in 1906 and was named after him2. Alzheimer’s disease is the most
common cause of dementia occurring mostly in patients over 45 years3. Generally, it is diagnosed
in people over 65 years of age4, although the less-prevalent early-onset Alzheimer’s can occur much
earlier. It is one of the most frequent mental illnesses, making up some 20 percent of all patients
in psychiatric hospitals and a far larger proportion in nursing homes 4. The incidence rate of clinically diagnosed Alzheimer disease is similar throughout the world, and it increases with age, approximating 3 new cases yearly per 100,000 persons younger than age 60 years and a staggering 125 new cases per 100,000 of those older than age 60 years. In India incidence rate is 324/100000/year above 65 yrs and 174/ 100000/year above 55 yrs .There is no exact epidemiological data of AD in Bangladesh.
The prevalence of the disease per 100,000 populations is near 300 in the group aged 60 to 69
years; it is 3,200 in the 70- to 79-year-old group and 10,800 in those older than age 80. In the year
2008, there were estimated to be more than 2 million persons with Alzheimer disease in the United States.
Prevalence rates, which depend also on overall mortality, are 3 times higher in women, although it
does appear that the incidence of new cases is only slightly disproportionate in women5.
Life expectancy of the population with the disease is reduced6.
The mean life expectancy following diagnosis is approximately seven years.7 Fewer
than 3% of patients live more than fourteen years8. Without advances in therapy, the number of
symptomatic cases in the United States is predicted to rise to 13.2 million by 20501. Alzheimer’s disease
is predicted to affect 1 in 85 people globally by The association between the pathological
features of Alzheimer’s disease and dementia is stronger in younger than in older9. About 15% of
cases are familial and this cases fall into two main groups, an early onset dominant pattern and a later
onset group whose inheritance is not so clear10. Approximately 10% of all person over the age of
70 years have significant memory loss and in more than half the case is AD11.