Alzheimer’s disease is the most common cause of dementia in the elderly population of western countries. From the neuropathological point of view, Alzheimer’s disease was diagnosed in the 50-60% of late onset cognitive impairment cases.
The incidence of the disease is similar in all of the world and is calculated as 3/100.000 new cases in people under 60 years of age, 125/100.000 in people aged >60 years . The prevalence is about 300/100.000 between 60 and 69 years of age , 3.200/100.000 between 70 and 79 years of age and 10.800/100.000 in people aged 80 years or older.
Age is the most important risk factor, but also the gender (the disease is more frequent in female than male, with a ratio about 2:1) and the presence of vascular damage factors (stroke events, cholesterol and atherosclerosis).
Mutations in several genes, transmitted with autosomal dominant manner, account for about 3% of cases affected by Alzheimer’s disease, whereas the majority of cases is sporadic, likely caused by the interaction of genetic and environmental factors.