I posted in the younger onset forum, but thought I'd address some other questions here that maybe some of you can answer.

(1) How is it that someone with no family history of dementia can develop it?  Is that common?

(2) I was watching the videos on the Alz parent site, with Joan Uronis and her husband.  She had a family history of dementia, and developed it herself. . . yet she had no genetic markers (or whatever it was) for it.  If that's so, how does the Alzheimer's develop if the patient has no genetic markers for it?

(3)  Again referring to her, how can someone develop Alzheimer's disease when their bloodwork and brain scans come out normal?  I totally don't get that, any clarity here would be great.

(4)  Have you or your loved one thought you had dementia, only to have your forgetfulness and memory issues be something else, like peri-menopause or menopause?  I'm wondering if what I'm experiencing isn't due to that, in addition to some bigger anxiety triggers lately.

(5)  Have you been diagnosed with dementia after having been diagnosed with other things?  If so, what were your symptoms previously "blamed on"?

Thank you for any answers, I really appreciate it.

So, I’m going to take a stab at this, and see how far I get in answering your questions. . .

This is a fairly recent study that will explain some of the “yes, but” considerations in the science of dementia discovery:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6534149/

You asked. . .

• How is it that someone with no family history of dementia can develop it?  Is that common?

While some dementias are familial, and there are known genome patterns that predict a higher RISK for dementia, it is not a 1:1 relationship.  You don’t need “the gene” in order to develop a dementia.  And, conversely, having “the gene” won’t purely predict its future occurrence.  These authors said it best, “Dementia is a complex disease often caused by a combination of genetic and environmental risk factors. Although many risk factors for the occurrence and progression of dementia have been identified, their utility for determining individual risk through dementia prediction models remains unclear” (Tang et al, 2015).

• I was watching the videos on the Alz parent site, with Joan Uronis and her husband.  She had a family history of dementia and developed it herself. . . yet she had no genetic markers (or whatever it was) for it.  If that's so, how does the Alzheimer's develop if the patient has no genetic markers for it?

Again, it isn’t a purely liner relationship, if marker then disease; or conversely, if NO marker, no disease.  The occurrence of neurological conditions is more complex than that.  Also, don’t confuse dementia (an umbrella term that can encompass over 50 kinds of conditions) with Alzheimer’s Disease – one particular kind of dementia.

• Again referring to her, how can someone develop Alzheimer's disease when their bloodwork and brain scans come out normal?  I totally don't get that, any clarity here would be great.

Here’s what the authors of that first study I cited concluded from their work: “We conclude that non-AD pathologies such as HS, TDP-43 inclusions, cortical ARTAG and Lewy pathology may increase the aged brain’s vulnerability to dementia independent of AD pathology, and that individuals with minimal CVD and the other non-AD pathologies may be more cognitively resilient to AD neuropathology. Although it is unknown what factors influence the accumulation of many of these pathologies, healthy aging choices may lower the burden of CVD and could reduce a person’s dementia risk in old age” (Robinson et al, 2018). 

Translated, this means that regardless of which pathologies shows up, (they include cerebrovascular disease (CVD), hippocampal sclerosis (HS), aging-related tau astrogliopathy (ARTAG), as well as TDP-43 and Lewy pathology), the INDIVIDUAL’s resilience to the disease itself is influenced by a number of factors, not just any single precursor.

•  Have you or your loved one thought you had dementia, only to have your forgetfulness and memory issues be something else, like peri-menopause or menopause?  I'm wondering if what I'm experiencing isn't due to that, in addition to some bigger anxiety triggers lately.

There are many things that mimic the symptoms of dementia – or may even BE a form of dementia, just not Alzheimer’s Disease.  Consider these diagnoses (to name only a few) – all forms of dementia, most related to another pre-existing condition:

• Alcohol-related dementia (ARD)
• Alcohol-induced persisting amnestic syndrome (Wernicke-Korsakoff syndrome, or WKS)
• Dyslipidemia & Diabetes related risks for dementia
• Vascular dementia (underlying cardiovascular disease or CVD)
• Parkinson’s disease related dementia
• AIDS related dementia (rare now that drugs are available to manage HIV infections).

Consider the differentiating symptoms of Alzheimer’s disease. . .

1. MEMORY LOSS THAT DISRUPTS DAILY LIFE.
2. CHALLENGES IN PLANNING OR SOLVING PROBLEMS.
3. DIFFICULTY COMPLETING FAMILIAR TASKS AT HOME, AT WORK OR AT LEISURE.
4. CONFUSION WITH TIME OR PLACE.
5. TROUBLE UNDERSTANDING VISUAL IMAGES AND SPATIAL RELATIONSHIPS.
6. NEW PROBLEMS WITH WORDS IN SPEAKING OR WRITING.
7. MISPLACING THINGS AND LOSING THE ABILITY TO RETRACE STEPS.
8. DECREASED OR POOR JUDGMENT.
9. WITHDRAWAL FROM WORK OR SOCIAL ACTIVITIES.
10. CHANGES IN MOOD AND PERSONALITY

And realize that these changes PERSIST, they are not fleeting, momentary or returned to normal after hang-over recovery.

• Have you been diagnosed with dementia after having been diagnosed with other things?  If so, what were your symptoms previously "blamed on"?

People blame their symptoms on everything imaginable – that‘s human.  

There are also diseases that cause dementia-like symptoms, but are treatable diseases which should be addressed and not ASSUMED to be Alzheimer’s Disease such as:

• Cushing’s syndrome with steroid-dementia
• Encephalopathy with dementia-like symptoms

Denial also occurs because we make it so difficult for people with dementia to come to terms with a positive future for themselves.  It is often society (the rest of us) that make life hard for people with ANY neurological disorder.  Yet, many people living with dementia(s) are not themselves constantly caught up in the stress or distress of the disease.  

This is not to say that we’re “done” learning how to care for people with dementia and that we’re doing a great job – often, we’re not (as Bartlett et al, 2017, remind us!).

Hope some of this is helpful!

--p

References:

Bartlett, R., Windemuth-Wolfson, L., Oliver, K., & Dening, T. (2017). Suffering with dementia: the other side of “living well’’. International Psychogeriatrics, 29(2), 177-179.

Robinson, J. L., Corrada, M. M., Kovacs, G. G., Dominique, M., Caswell, C., Xie, S. X., ... & Trojanowski, J. Q. (2018). Non-Alzheimer’s contributions to dementia and cognitive resilience in The 90+ Study. Acta neuropathologica, 136(3), 377-388.

Tang, E. Y., Harrison, S. L., Errington, L., Gordon, M. F., Visser, P. J., Novak, G., ... & Stephan, B. C. (2015). Current developments in dementia risk prediction modelling: an updated systematic review. PLoS One, 10(9), e0136181.