What exam determines the stage the person with Alzheimer is in?

The stages are generalities and different for everyone. Some will have parts of stage 3, 4, 5, others will have parts of 2, 4, 6. The stage is determined on a score from the "mini mental status test" which can be administered by a social worker. Some use early, middle and late instead of numbers. The numbers are very misleading because people will experience deficiencies in several areas. This is where the overall score from the MMST comes in.

Check out the Alzheimer's Association website they have the stages all written, activity deficiencies, etc.

Jeanne, the AL and NH facilities now want a stage prior to placement. Families will opt for less expensive AL care, but the facility will have two separate staff interview the prospective client to determine if they can actually function. Independent Living apartments will take mom, they have no medical staff, but they will also tell you to move her out ASAP when it's not working.
Treatment of co-morbidities is affected. If a patient has late stage Alzheimers and needs a hip replacement, insurance may say no, because the patient cannot participate in the recovery process nor do any PT. HMO's now demand that the Primary Physician certify the patient ready for surgery.
Legal matters are affected. If you want Guardianship for someone in early dementia, the judge may not agree. On the other hand, a man with later dementia sued his children for taking away his car. Not only did the judge rule against him, he appointed a guardian.
And of course over time, the stage will change, sometimes overnight.

Usually a complete exam is done initially to determine the type of dementia, whether is is vascular, lewy body, alzheimers. The follow up exams don't need to be so detailed because they have already narrowed down the scope of treatment. At the very minimum I would want an annual review. If there are sudden changes or symptoms that don't make sense other tests will be ordered.

pstegman, is this typically done several times throughout the course of the disease, to determine the present stage? What is the value of knowing the stage? (You can tell I haven't dealt with this.)

It's called a Neuro-Psych exam, and the primary physician can order it.

Good question. I always thought it was a matter of observing symptoms and behavior. Maybe there is a test. I hope someone knowledgeable about this topic answers.

My husband had Lewy Body Dementia, which does not progress in stages, and I'm interested in how stages are determined for Alzheimer's, too.