I can’t comprehend how dementia symptoms seem to come and go. Anyone else have experience with this?

Maybe cerebral small vessel disease. My mom was like this for years. Teeny tiny blood vessels in the brain are sometimes leaking blood. When one of these leakages happens, the person has period of "bad" days or weeks. Then gradually the brain recovers a bit and the person has a period of "good" days or weeks. This link will give you tons of info (perhaps too much info!) https://betterhealthwhileaging.net/?s=cerebral+small+vessel+disease

It could be ischemic strokes which display temporary symptoms.

When Mother acts 'kooky' YB says it's because she has dementia. When she is just being her, he says she's perfectly fine. Trying to ascertain whether she truly does or doesn't have dementia is impossible for someone not living with her. I say she does--actually, I don't really care. But it would explain away a lot of cruel comments and behaviors.

He refuses to allow her to be tested. I'm sure she has good days and bad, but either she has some type of dementia or she doesn't. Period. It would make dealing with her a LOT easier if you could 'blame' the dementia.

He’s 81. I’ve noticed memory problems for the past 5 years or so? He’s been gradually getting worse. This past year has been unbelievable. Very confused at times.

? What test would be "hours long"?

This is what is puzzling me - Tiny areas of brain which are killed off by tiny strokes do not recover. That is why vascular dementia is commonly described as being characterised by "steps" - the person trundles along enjoying much the same level of function, then an element gets lost, then maybe another element soon after that, then there's another plateau of time during which nothing much changes, then... and so on and so on and so on.

What can happen after a stroke (of any size) is that the brain creates new pathways to restore a particular function, so that patients do get movement, speech, vision, swallowing back after a period of recovery, but especially if they are younger and supported by therapies. What doesn't happen in vascular dementia is the sort of "good days/bad days" ups and downs rollercoaster that is more typical of Alzheimer's Disease; and yet that's what you seem to be describing with your father.

It is true that there's a limit to how useful (not to mention certain) a precise diagnosis can be; but it's also true that there are things that are worth ruling out. How old is your father, and how long has he been ill?

Thank you for your comments. The neurologist gave him the cognitive tests and he didn’t do very well at all. She also looked at his mri and noticed a lot of white matter. She said most likely caused by tiny strokes. Although no major strokes have happened. The test she recommended to determine for sure which type would be hours long and my father refused. Can’t say I blame him. She said it really doesn’t matter which type, they are treated same way. My father refuses memory pills, and refuses to go back to her since her diagnosis was incorrect he says

My father's degree of impairment would often fluctuate depending on how much medication he had taken. He was prescribed meds for high blood pressure, angina, anxiety, depression, osteoporosis, and chronic pain. Instead of taking his medications as the doctors directed, Dad would take his blood pressure and then take the meds in the amounts he felt he needed. Apparently high blood pressure, even when it didn't result in additional TIAs, impedes brain function. Instead of taking low doses of an anti-anxiety medication, Dad would not take it at all for several days and then take multiple doses when he felt a panic attack coming on so withdrawals and overdosing caused additional problems. He would not cooperate or take his medications as directed for any family member and disagreements within the family over his care prevented anyone from just taking his medicine bottles and only providing a daily or weekly med box. Once dad entered MC, he did take his medications for the staff there and experienced an immediate improvement in his overall health and daily functioning levels too; he "stabilized".

Geriatric diabetes impacted an extended family member, please make sure the A1C level test is included in your father's blood work.

Dementias all differ. I know there are even charts to show how they differ, and in some things can be good one day and very bad another. Many dementias also react to the level of anxiety the person is experiencing on any given day. The earlier years of Lewy's can be notorious for being up, down and all over the place. I know that is the case for my bro, and anxiety of any kind can make it very bad indeed, where a relaxed state can make him "good as he ever was". He is still in early stages and can RECOGNIZE how bad any anxiety is for him. So yes, things can vary day to day.

Does your father have a history of any vascular issues? An MRI can show vascular changes and strokes. Is your dad going to have an MRI? When I was finally able to read my mom's MRI reports I saw that she has chronic small vessel disease and atrophy. She also had a stroke in 2014. This was prior to her diagnosis but she had just moved here and I was seeing all kinds of alarming behavior so I took some of her records to my own doctor and asked "Am I dealing with vascular dementia?" With zero hesitation he said yes.

Later my mom had her own neurology appointment and the new neurologist reviewed all her old records and also told me vascular dementia. She then had a neuro-psych eval and that diagnosis was dementia of mixed etiology.

What I have since learned, from somebody here actually, is that vascular dementia can present as you describe, one minute almost normal, then nonsense. The explanation was that depending on what vessels are being affected some parts of the brain are more damaged where other parts can still be okay. Progression happens when more damage occurs like TIA's or another stroke, but even the small vessel changes cause progression too.

Anyway not sure if all that rambling helped, I just wanted you to know I see it in my mother too. Like your father she is also in denial.

As your father's neurologist pointed out, more tests are needed. The sort of recovery you describe is not typical of straightforward vascular dementia. If I were you I'd start keeping a daily journal of what tasks and activities your father is able to manage and offer it to the neurologist - it might be very helpful for differential diagnosis.

What investigations have already been done?

My dad is in advanced stages now but we did go through this. I used to think maybe I was losing my mind and maybe he was actually ok. He would go from being unintelligible to speaking sentences. As he progresses there may be all kinds of behaviors that will be difficult . He may get angry, flirtatious etc. Just keep in mind they can not control their odd behavior even though sometimes it seems like they should have known better. I remember getting upset with my dad because he had a bowel movement on the restroom floor of a restaurant. He was laughing about it and I kind of lost it with him because I thought he did it on purpose. The more time passed and I studied up on the disease and have watched the deterioration I look back on that moment and it makes me sad. His brain was broken even though at the time he could be normal at times. This disease is full of unknowns and it becomes so difficult over time to slowly watch your loved one slip away.