Complicating Alzheimer's Disease
Researchers have demonstrated an Alzheimer's therapy that removes amyloid plaque, but that doesn't halt or reverse neurodegeneration: "The theory was that dementia could be slowed or reversed once the plaques were cleared, and experiments in animals have shown that removing these plaques improves brain function. ... long-term follow-up of Alzheimer's patients treated with [the therapy] did show, 'a reduction in the number of plaques in the brains of patients -- in some cases there was a virtually complete removal of plaques. Crucially, there was no evidence that the patients benefited by the removal of plaques and even those subjects with virtually complete removal continued to deteriorate and had severe end-stage dementia prior to their death.' ... [researchers now believe] that removing plaques - at least by this method - is unlikely to make a significant difference to the clinical outcome of patients with established Alzheimer's disease ... it strongly suggests that plaques are not sufficient on their own to account for disease progression."
Link: http://www.washingtonpost.com/wp-dyn/content/article/2008/07/18/AR2008071801614.html