What are the most accurate test in diagnosing Dementia/Alzheimers?

I'm sorry about your mother. Unfortunately there isn't any real way of diagnosing Alzheimer's. Mostly it is based on presentation such as confusion, dementia, forgetfullness. Most Imaging exams only exclude other possibilities and help rule in Alzheimer's. as stated earlier, the only real way is an autopsy, where they will actually find specific protiens in the nuerons. Be as that may, there isn't a cure and the treatment is only supportive. Acetyl-Choline esterase Inhibitors have been found to be useful in decreasing the demetia by increasing the nuerotransmitters in the synaptic clef and allowing longer firing of Nuerons.