Should I go through any more tests to follow my husband's dementia?

Don’t do it. As others have mentioned, why? We know our loved ones are spiraling downward every day. Dementia patients have a terminal disease. Trying to help them understand invasive and other tests is a huge task in itself. Enjoy each day with them and strive for the best life they can live on this day.

PET scans are the “definitive” test for AD. A radioactive compound is injected into the patient which binds to the amyloid plaques and “lights them up”, thereby verifying the presence of the plaques. The plaques along with tau tangles are telltale biomarkers of AD. An MRI can detect vascular issues and also abnormal shrinkage of the brain, a sign of possible AD.

Now forget what I just wrote. Some people who show signs of dementia symptoms and possible AD, have no accumulation of amyloid or tau buildup. On the other hand, patients who have significant buildup of those proteins, may have no cognitive decline. So someone showing noticeable cognitive decline, may show no amyloid deposits on their brain from a PET scan. That may be the reason for your husband's negative scan assuming he's been evaluated for all the other dementia causes.

I don't see how annual MRI's and screening will help your husband. You know you're dealing with dementia of some kind, and you know it will get progressively worse. A spinal tap may be worthwhile if they are looking for an underlying condition not related to dementia diseases. I wouldn't rule it out. After having an MRI which showed normal shrinkage for someone her age, and an all-day neuropsych screening, drs could not tell me what the cause of my wife's dementia was either (although I suspected AD). Her death certificate read “dementia”. So I would forget the stages and even the cause and just do your best to address his symptoms as they come up.

The short answer to your question is no, you shouldn't keep putting him through these tests. And who cares what "stage" he's in? You already know he has some type of dementia, and even though it may not be Alzheimer's(which you should be grateful for as that can go on for up to 20+ years)there are many many more types of dementia.
The simple fact though is that your husbands brain is broken and will never get better only worse, and you now have to figure out the best option for his care.
People with a broken brain don't like their routines disrupted as I'm sure you already know and dragging him to this doctor and for this test only makes things worse for him and you. There are no medications to stop or slow down the process or to cure it, so why continue to put him and yourself through this?
Instead educate yourself best you can on dementia, so you will be better prepared going forward, and then start getting your "ducks in a row" for his future care.

When my late husband was diagnosed with vascular dementia in July 2018(even though he showed signs a good year before)and at that time given a life expectancy of 5-7 years(it has since dropped to just 5 years)I knew that I would no longer put him through any unnecessary tests or appointments again and would try and make his time left here on earth as pleasant as possible for him, as he deserved that much, and so did I.
My husband was under hospice care in our home for the last 22 months of his life and died Sept. 2020.

I wish you well on this journey with your husband. God bless you.

To do an invasive test like a spinal tap to check for conditions that haven't appeared elsewhere seems ludicrous to me. My mother had progressive dementia that was diagnosed ONLY with a SLUMS test and nothing more. Her neurologist was such a waste of time and money, that I fired her after 2 visits in the hospital and refused a follow up visit after mom's release. She flat out told me there was NOTHING she could do for mom's dementia or her neuropathy, but here's my huge bill, thank you very much. And then had the nerve to act shocked when I told her I would not be needing her services in the future, thank YOU very much.

In reality, there's nothing TO be done for dementia except prescribe anti depressants or calming meds for mood issues.

Do whatever you feel is right but don't put your poor husband thru painful and invasive tests for the likelihood of more inconclusive results. And if AD is diagnosed, what's to be done for it anyway? And if this neurologist is wondering why he's gotten progressively worse lately, does he not understand that dementia GETS progressively worse and rarely shows up on ANY tests other than cognitition exams??????

Best of luck.

I have never heard of getting an MRI yearly to track the Dementia. I would have had one done to determine if there was Dementia/ALZ and what type and it was confirmed Dementia was in the picture, there really is no need for another IMO. You can tell by living with someone that the disease is progressing. And it does, some slowly, others faster. Decline can literally happen overnight.

"Magnetic resonance imaging (MRI) is often considered superior to CT in dementia imaging [2], in particular for demonstrating vascular lesions and for identifying additional pathology, e.g. microbleeds and white matter lesions.May 2, 2019"

"What can brain scans tell us about dementia?
The two characteristic changes in the brain of people who have Alzheimer’s disease are clumps of toxic proteins called amyloid and tau."

I am not a Nurse or a doctor but I would go with the MRIs in reference to ur husband. It seems Pet scans are more for looking for ALZ than other Dementias. So, ur husband does not have ALZ. I don't know about putting him thru a spinal tap. They have to be awake and are given a local. They have to remain very still. Can your husband follow directions?

I may do the spinal tap for peace of mind. But after that I would not put him thru anymore tests if the spinal tap shows nothing. If husband is not on depression medication I would ask that he be placed on it. Dementia itself may run its course in 5 to 7 years. My Mom lived 6 years from diagnosis. ALZ is longer, my Aunt lived 12 yrs from diagnosis.

So sorry you are going thru this, but no one can tell you how long a person has with Dementia.

I found a Neurologist, after the initial diagnosis, to be about as useful as "tits on a bull"
The only one that gained anything from the subsequent visit..and there was only 1..was the doctor when he got the co-pay.
Now I did get my Husband in a Drug Study and he did have a spinal tap ONLY because of the study. I would not have put him through it if it was not necessary.
As he declined I would not have subjected him to any testing as that would have been difficult to do as he was not compliant and he would have had to have been sedated and that would have made the dementia worse.
Stage....You know where he is by your every day observations. You can look at any number of charts that list the stages and highlight what he still can do and what he has lost. there is always going to be items on the list that he can do longer, some items he will lose sooner than "average" but it will give you an idea where he is.
What I would encourage you to do is contact a Hospice in your area, as a matter of fact contact more than 1. Have your husband evaluated and take full advantage of all that Hospice can offer in the say of supplies and equipment.
And if your husband is a Veteran contact the local Veterans Assistance Commission and find out if he would qualify for any services from the VA.
I would not have been able to care for my Husband without the help of both Hospice and the VA.

A spinal tap can be used to help diagnose AD. Also could help rule out another cause. You might want to Google 'Alzheimer's' + 'spinal tap'.

Some information here:
https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/normal-pressure-hydrocephalus

Overall, are you happy with your husband’s neurologist? If you aren’t and there are other options in your area, consider switching to a new doctor.

Maybe a fresh pair of eyes will help. I have changed doctors when I haven’t been satisfied with their quality of care.

Are the neuropsych exam results remaining stable or is there progression of his cognitive loss?