The primary target has been to improve the deficits related to cholinergic deafferentation which is present in AD primarily in the amygdala, hippocampus, and neocortex. Recently, a large multicenter trial of Tacrine, an acetylcholinesterase inhibitor, was published with several hundred AD patients. There were mild improvements in cognitive scores and smaller declines in performance of activities of daily living than patients without treatment, but no differences in global rating scores. The conclusion of the study was that Tacrine produced a statistically significant reduction in the decline of cognitive function and may provide some benefit to some AD patients. These include the presenilins, tau, APP, the cleavage of APP, amyloid deposition, etc.
Parkinsonian symptoms can be present in several neurodegenerative disorders.
This disorder affects individuals in the sixth decade of life and affects males and females equally. Parkinsonian syndromes were also recognized in the early twentieth century following the influenza pandemic. This is referred to as Post Encephalitic Parkinsonism. Experimental parkinsonism has been created by inadvertent exposure to the mitochondrial toxin called MPTP, an analogue of meperidine which was inadvertently made as a designer drug of abuse. The vast majority of PD patients are sporadic although several autosomal dominant pedigrees of parkinsonism have been identified.