Hunting Alzheimer’s Early Signs - Science in 2011 - NYTimes.com

Few, if any drugs are able to check Alzheimer's disease once it is diagnosed, by which time a great deal of brain tissue is already blown away. Nevertheless, several regimes appear, with retrospective studies,  to reduce the incidence of Alzheimer's disease. If one could detect the disease earlier, perhaps these  have a chance of delaying Alzheimer's disease.

There are some treatments that have proved effective. These are very rare and isolated cases, but in the total absence of any other avenue, perhaps these should be tested further: There are two instances of a "cure" for misdiagnosed Alzheimer's disease , which turned out after 2-3 years of hopitalisation to be a cryptococcal infection, (C.Neoformans) Ala et al, 2007 Hoffmann et al, 2009 . Slight beneficial effects have been noted with plasmaparesis (antibody/antigen removal)  Boada-Rovira 2010 or with the TNF inhibitor etanercept Tobinick and Gross 2008 .
Small and rare effects indeed, but are they not worth further study ?