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Reposted by Rachel Howard

Ian Kremer @leadcoalition.bsky.social · 17d

The difference between Alzheimer's disease and other dementias alzheimer.ca/en/about-dem...

#Alzheimers #dementia #health #wellness #WorldAlzheimersDay #AskAboutDementia #AskAboutAlzheimers #WorldAlzMonth

Dementia is an umbrella term used to describe a range of neurological conditions affecting the brain that get worse over time. This infographic from the National Institute on Aging at NIH describes four different diseases that cause most cases of dementia: Alzheimer's disease, frontotemporal degeneration (FTD), Lewy body dementia (LBD), and vascular contributions to incident dementia (VCID).

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Rachel Howard @rachel-h-iow.bsky.social · 18d

Ebba's feeling was more work needs to be done to demonstrate its value as a diagnostic test: www.sciencedirect.com/science/arti...

Monitoring the follow-up of autoimmune chronic atrophic gastritis using parietal cell antibodies and markers of gastric function

Increased interest in the pathogenesis and the evolution of autoimmune chronic atrophic gastritis (A-CAG) has led to the search for serological marker…

www.sciencedirect.com

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Rachel Howard @rachel-h-iow.bsky.social · 19d

doi.org/10.1136/bmj-...
I would also read this. It's a brilliant starting point.

Vitamin B12

### What you need to know Vitamin B12 (cobalamin) is a water soluble vitamin required for several physiological processes, including normal nervous system functioning, and red blood cell development ...

doi.org

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Rachel Howard @rachel-h-iow.bsky.social · 19d

doi.org/10.1136/bmj-...
This paper is also really helpful and may help you track back to the original research. But it's decades old.

Vitamin B12

### What you need to know Vitamin B12 (cobalamin) is a water soluble vitamin required for several physiological processes, including normal nervous system functioning, and red blood cell development ...

doi.org

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Rachel Howard @rachel-h-iow.bsky.social · 19d

PPIs and Metformin are recognised as risk factors for deficiency. Deprescribing is ideal if they are no longer needed, but if they are needed, oral treatment with B12 will suffice for PPIs, but less so for metformin (either B12 injection or combining oral with calcium & vit D improves absorption)

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Rachel Howard @rachel-h-iow.bsky.social · 19d

I suggest contacting the Pernicious Anaemia Society who do excellent patient advocacy and support. pernicious-anaemia-society.org

Pernicious Anaemia Society | Improving the Diagnosis & Treatment

We provide information, help and support to sufferers of Pernicious Anaemia. We aim to change the way in which Pernicious Anaemia is Diagnosed and Treated.

pernicious-anaemia-society.org

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Published March 2024. Not perfect, but better than the nothing that went before.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Even if levels are broadly "normal" (levels are difficult to interpret if taking oral supplements or fortified foods because they will be falsely raised), it would be worth a try because it's a low risk, low cost intervention with a clear symptomatic response which can guide future treatment.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

I wouldn't treat just based on a result, but if you've got someone with dementia type symptoms, who has balance problems and seems quite deconditioned and needs to sleep a lot. I would have a low threshold for trying b12.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

And check co-factors for B12: iron, folate and also vitamin D. They're often all deficient and need to be well topped up for B12 to work efficiently.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Review symptom change after treatment (e.g. after 6 injections over 2 weeks, or after 3 months of oral if no neurological symptoms). If severe neurological symptoms may need a 3 month trial to see symptomatic change. Also, symptoms may worsen initially, this still indicates deficiency.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

If you follow the NICE guidance then you should be considering treatment. In general, they have relevant symptoms (fatigue, neuropathy, anxiety, mouth ulcers etc.) and a risk factor (diet, family history, autoimmune disease, gastric/bowel surgery/radiotherapy etc) then consider treatment and

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Definitely! Perhaps we could tie it in with the publication of the new local guidance once it's approved by the ICB.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Even combining all the tests together doesn't give a completely accurate diagnosis. Possibly because B12 is a "passerby". So the hunt for an optimal diagnostic tool goes on.
One option is to combine clinical signs with biomarkers. And a number of delegates are applying for funding to do just this!

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Rachel Howard @rachel-h-iow.bsky.social · 19d

So in the 1980s the hunt began for other biomarkers and MMA and Homocysteine were discovered. BUT, MMA is too expensive and not widely available and homocysteine is non specific.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Because the serum B12 can give surprisingly high levels of false positives (unnecessary painful injections) and false negatives (dangerous symptom progression due to missed diagnosis) neither clinical treatment nor scientific study should rely on blood test results alone (but both usually do).

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Even the measurement of B12 levels is not accurate. Serum B12 measures cobalamin which is unavailable to the cells. Measuring transcobalamin (active B12) is not sufficiently more accurate to warrant its increased cost. But at least the process for serum B12 is now automated to reduce the cost.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

We used to have the Schilling test (based on radioactive B12 and whether it came out in your urine) but this is no longer available and the alternatives have proved to be too complex or expensive to become widely used.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

The next step was to identify what was wrong. This was not, and is not, straight forward. The tests lack sensitivity (intrinsic factor antibodies) and specificity (parietal cell antibodies) so the gold standard remains gastric biopsy! (not routinely done)

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Rachel Howard @rachel-h-iow.bsky.social · 19d

Starting with the recognition of an unknown condition in the 1800s which was treated with strychnine and splenectomy (unsuccessfully). The breakthrough coming with the discovery that 200g of raw liver a day was life saving! Followed by purification of B12 containing liver extract in the 1950s.

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Rachel Howard @rachel-h-iow.bsky.social · 19d

This afternoon at CluB12 a fascinating overview of the history of B12 deficiency/pernicious anaemia from the amazing Ebba Nexo who has spent her whole career working in this field.

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Rachel Howard @rachel-h-iow.bsky.social · 20d

Some of these processes result in pseudo B12 which can't be used by plants or animals!
Lots of work is being done to maximise production which is so important for food supplementation for sustainable plant based diets, but also to ensure we have enough B12 for pharmaceutical production!

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Rachel Howard @rachel-h-iow.bsky.social · 20d

Today at CluB12. I've never really thought about how vitamin B12 is produced. Only bacteria can make it naturally, but some algae can concentrate it, hydroponics can be used to concentrate it in some plants (pea shoots). But some plants can be genetically modified to produce it (tomatoes and rice).

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Rachel Howard @rachel-h-iow.bsky.social · 20d

I've not thought much about riboflavin before (except as migraine prophylaxis), but it can lower blood pressure and deficiency in pregnancy is very common.

Rachel Howard @rachel-h-iow.bsky.social · 20d

The balance of B vitamins is also really important. If one is low, the others won't work properly.

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