How is Alzheimer's disease diagnosed?
Videos
Aug 9, 2017
Click play to watch the video or read the video transcript.
Dr. Larry Lawhorne discusses how Alzheimer’s disease is diagnosed.
How is Alzheimer's disease diagnosed?
The interesting thing about making the diagnosis of Alzheimer's disease is that the history that your healthcare professional gets from you and your family, from the person with suspected Alzheimer's disease in the family, history is the most important thing. Sometimes, you really have to drill down to get that because sometimes, family members and others have provided enough cues and enough hints that a person’s deficits aren’t always seen right away.
You really have to start asking very detailed questions like, if he’s not interested in doing the checkbook anymore, tell me more about that. Is he not interested or do you think he’s having more problems doing the math? If you're having to remind him that Thursday’s trash day and it’s Wednesday night, is it just because he’s been cantankerous or is it because he doesn’t remember it’s Wednesday night or he doesn’t remember the steps and the process to go around and get the trash and those kinds of things? When you're being evaluated, you should expect for the examiner to really drill down for those things.
Now, once we think someone has a memory problem or a thinking problem, then we do some very specific testing. Baseline testing would include either something called the Montreal Cognitive Assessment test or the Mini-Mental State Exam. Each of those contains 30 items. The top score would be 30 and you score things like, I’m going to give you five words to remember and I want you to tell me what those five words are now. Then, I’m going to ask you those five words later, so it’s important for you to remember those. We ask things like similarities. If I said, “How are banana and an orange alike,” you would say they’re both fruits, right? Then, I would say, “Well, how are a train and a bicycle alike or how are a watch and a ruler alike?”
What we find sometimes in people with early dementia is that they can describe each one of those. They can say, “Well, you know, a train is something you buy a ticket for and you had to pedal a bicycle,” but they won’t be able to say they’re both means of transportations, they’re both ways to get from point A to point B. We have another one where we give them a couple of sentences that we want them to repeat the sentences exactly the way we say them to them but the sentences don’t flow really well and so, they have to pay really close attention to be able to repeat that back.
We do some things like, “I’m going to give you five digits forward and I want you to tell me the digits just the way I say them.” Then, you say 75861 and they’re to repeat that. Then, you say, “I want to give you three digits. I’m going to give them forward. You give them backwards. 741.” They should say 147. All of these tests will give us some information about a person’s ability to remember and think. That’s the baseline that we do.
The other thing that we think about in addition to the history and doing this memory testing like this is a really good physical exam because one of the things we want to know is, does the person have any deficits and strength or coordination or any of those kinds of things that might make you think that they’ve had a little stroke in the past, something very subtle but that might lead you to think that it’s more vascular dementia than Alzheimer's disease.