Approaches to palliative therapies for Alzheimer's disease

Alzheimer's disease is a progressive neurodegenerative disease characterized by gradual and increasing loss of cognitive function and behavioral abnormalities. The formation of beta-amyloid plaques and neurofibrillary tangles are recognized as the key pathologies of the disease. Changes in the levels of various key neurotransmitters has been noted in patients with Alzheimer's disease and may represent the earliest biochemical casualty, preceding or signifying the onset of the disease. Over the last 20 years a number of approaches to the palliative treatment of Alzheimer's disease have been scrutinized. The majority of effort has been focused on cognitive dysfunction, as this is the initial and key debilitating symptom of the disease. The identification and commercial development of the acetylcholinesterase inhibitors has, until recently, virtually dominated the field, and although efficacy has been demonstrated, the clinical results suggest alternate approaches are warranted. This review will highlight those palliative approaches that have focused on the improvement of learning and memory and not on the disease-modifying strategies of the beta-amyloid, tau phosphorylation or other neurodegenerative hypotheses.