What is necessary for a proper diagnosis of alzheimer's disease beyond signs of dementia?

No sepecific test: There's no specific test today that confirms you have alzheimer's disease. Your doctor will make a judgment about whether alzheimer's is the most likely cause of your symptoms based on the information you provide and results of various tests that can help clarify the diagnosis. Alzheimer's disease can be diagnosed with complete accuracy only after death, when microscopic examination of the brain.

Test exam: A full exam by a qualified expert in the field; MRI or ct of the brain often done; lab work to r/o reversible causes; consideration of depression as a cause or contributing; a full review of medications; avoidance of alcohol; consider full neuropsychol testing as well.