Alzheimer’s dementia is the most common form of intellectual decline syndromes.
It can be assumed that 2-4% of the population over the age of 65 is affected by Alzheimer’s dementia. The disease is more common in women due to longer life expectancy. The incidence rate is estimated to be about 1% per year. The probability that a person will have severe dementia by the age of 80 must be put at about 20%. More and more citizens in western industrialized nations are reaching the manifestation age of Alzheimer’s disease, the prevalence of which will thus continue to rise. In Austria, the number of people suffering from Alzheimer’s disease is estimated at around 90,000.
Acetylcholinesterase inhibitors (e.g. rivastigmin) and memantine are currently available for the treatment of cognitive and functional deficits of Alzheimer’s dementia. The principle of action of acetylcholinesterase inhibitors is to improve neural availability of acetylcholine, which is reduced in Alzheimer’s dementia, by inhibiting the degrading enzyme cholinesterase or butyrylcholinesterase (cholinergic hypothesis). The efficacy of treatment with acetylcholinesterase inhibitors for mild and moderate forms of AD as “first-line” therapy has been widely demonstrated. Evidence of efficacy has been obtained in randomized, placebo-controlled trials and has also been confirmed in meta-analyses. A particular challenge is patient compliance. Memantine has an antagonistic function on the NMDA receptor and serves to regulate glutamate balance. Currently, memantine is prescribed to patients with moderate to severe AD.1
1 Fleischhacker & Hinterhuber. Textbook Psychiatry. Springer Vienna New York 2012, 370-372.