How often should a dementia patient have MRI testing done??

My mother had a few MRI's and was medicated with Ativan for each one in the past. I was allowed to sit in with her on a plastic chair near her and hold her hand/ leg. She did quite well and seemed relaxed, but now at 98 years old, I wouldn't put her through another MRI.

Normally a single MRI can tell the doctor what he needs to know. Is the doctor trying to determine the cause of his dementia? An MRI can rule out treatable conditions and also confirm certain conditions. It can detect if very small vessels in the brain have become damaged because of high BP, smoking, high cholesterol, or other factors that may have caused mini strokes. Anything that robs the brain of blood and oxygen is suspect thereby suggesting VaD. It can indicate abnormal shrinkage of the brain maybe implying AD.

But as others have mentioned, it may be difficult for your dad to undergo this procedure. He'll have to lie still for 30 minutes or more. Is he claustrophobic? Talk to his dr about the need for this procedure.

Is the MRI for his dementia? Your profile says your dad is 85. Like the others have stated, I can't imagine getting him to stay still for this procedure, having had a few myself.

Please write back with the "why" he needs an MRI in the first place and what his doctors hope to accomplish.

Please keep in mind, tucked in the back, that lab work and testing is a profit center for medical practices, especially if they have a stake in the lab.

Perhaps once, just to rule out treatable things like stroke, tumours or Normal pressure hydrocephalus.
And having been in the MRI tube myself - I can't imagine putting anyone with dementia through that unless they were fairly heavily sedated.

Is there a need? Are there other conditions that need to be watched?
If there is no medical need I would not put someone with dementia through any testing. And I do mean ANY testing.
And a few other things to consider.
If the person has to be drugged to get them to remain still for an MRI there are problems with anesthesia or heavy duty drugs that will keep them "fogged up" for a while. (bad enough having a brain that is foggy in it's normal state adding drugs that will take a while for the body to process and rid is more of a problem)
Will the MRI show that the condition is worsening ..you know that from watching the person day by day, week by week decline.
IF you are watching for a medical condition what are your plans IF anything is found? Would you do follow up treatment or testing. If not the MRI results mean nothing.