"Subacute" "Combined" spinal cord degeneration, decoded?

[WiscGuy]

An ongoing question is the meaning of the initial terms of Subacute Combined Spinal Cord Degeneration. Jade recently posted a link to the article,

"A Case of Subacute Combined Degeneration of Spinal Cord Diagnosed by Vitamin B12 Administration Lowering Methylmalonic Acid"

I was grazing through the references and came across this one:

"Subacute Combined Degeneration One Century Later. The Neurotrophic Action of Cobalamin (Vitamin B12) Revisited"

academic.oup.com/jnen/artic...

At the top of the article was this:

[Start]

It was exactly 100 yr ago when Russell et al published the paper in which they first suggested the term “subacute combined degeneration” (SCD) to define the neuropathy observed in association with pernicious anemia (PA). The reasons for this definition were the rapid course of this neurological disease, which usually affects the peripheral nerves and the different columns of the spinal cord (SC), leading to a combination of tract degeneration.

[Stop quote]

So, apparently, "rapid course" is somewhere between acute and chronic.

Wikipedia has an entry for "subacute combined degeneration of spinal cord". The entry includes the following description of"combined". (Wikipedia entries are often reviewed by peers, but it does not have a formal peer-review process):

[Start quote]

"In subacute combined degeneration of spinal cord, the "combined" refers to the fact that the dorsal columns and lateral corticospinal tracts [of the spinal cord] are both affected, in contrast to tabes dorsalis which is selective for the dorsal columns."

[Stop quote]

So, "combined" refers to involvement of those two components of the spinal cord.

[Narwhal10]

So, for those who need a bit more information.

1) dorsal columns - (think, dorsal fin like a dolphin🐬 ) - so referring to back.

2) lateral corticospinal :-

lateral = side

corticospinal is a pathway, (think of an electrical cable from the back of a lamp to a socket). It runs from an area of the brain in to the spine.

3) tabes dorsalis - is much slower, seen in other illnesses.

Tabes comes from the Latin meaning decay.

It’s rather interesting that it was published in February 2001. 😉

[Nackapan]

Tried to put a'like ' but wouldn't do it ?

[Jillymo]

It seems degeneration of the spinal cord can affect the body temperature, I overheat profusely. You might also find this link of interest------ncbi.nlm.nih.gov/pmc/articl...

So much to read and learn about this dreadful illness.

If only my fuzzy head would absorb the knowledge of what I read .

[FlipperTD]

Scientist, not medic.

I remember being told that Subacute Combined Degeneration of the Spinal Cord was often a misnomer, as it covers a range of conditions. Sometimes Acute, and not always Combined! This is a bit like Pernicious Anaemia. Typically Pernicious, but not always Anaemic.

However, I like reading up on stuff like this. thanks for posting.

[Cherylclaire Forum Support in reply to FlipperTD]

Did a quick google of Subacute Combined Degeneration of the Spinal Cord -but cannot find any other causes apart from B12 deficiency, or use of Metformin etc which amounts to the same thing. Will keep looking.

[Narwhal10 in reply to Cherylclaire]

Yes, I too had a browse. I went on PubMed and scanned 10 papers of the 736. There were no results on the Cochrane database.

I opted for ones that were less than 5 years old because I know that is what you are supposed to do 😉. So, they were dated between 2021 -2023.

All of them said vitamin B12 deficiency was the causation of Subacute Combined Degeneration of the Spinal Cord. Several of the studies looked at nitrous oxide use being the root cause.

Therefore, in my humble opinion, this has implications for dentistry, anaesthetics, obstetrics, emergency services and recreational use.

🐳

[jade_s in reply to Cherylclaire]

Of all the papers I've read about SACD - admittedly a small handful but dating over various decades - they were all due exclusively to B12 deficiency. Other neurodegenerative diseases cause a different pattern, from what I understand.

After saying that, I've looked in google scholar with the following search differential diagnosis of Subacute Combined Degeneration of the Spinal Cord (paging Narwhal10 )

scholar.google.com/scholar?...

and of course the first paper says "The differential diagnosis of subacute combined degeneration is broad..." BUT they do not give these various possibilities.

Other papers are behind paywalls, but from what you can see in the description, HIV and neurosyphilis are mentioned. So I suppose the disclaimer could be "after ruling out easily detectable diseases, B12D remains the primary cause of SACD"

This other paper, not behind a paywall, says "Differential diagnsosis for bilateral posterior column involvement [2] include infectious myelitis, infarction of spinal cord, inflammatory demyelination including multiple sclerosis, acute disseminated encephalomyelitis, acute transverse myelitis, and copper deficiency myelopathy. " ncbi.nlm.nih.gov/pmc/articl... [Note they say posterior = dorsal]

However they continue "Once the diagnosis of SACD is suspected, treatment with vitamin B12 injection should be started as early as possible to avoid irreversible neurologic damage [3]. Recognition of the specific MRI pattern of cord involvement together with clinical and laboratory analysis helps in early detection and treatment of the Subacute combined degeneration of the spinal cord."

I didn't go beyond the first page of results but worth investigating.

Thanks for the discussion WiscGuy!

[Narwhal10 in reply to jade_s]

Excellent work Smithers (I’m pretending to be Mr Burns from the Simpsons 😂🤣).

The infectious, the inflammatories and the encephalopathies are there but meh, for our audience, I likes basic me. (I am using my regional accent 😃).

👍🏻

[jade_s in reply to Narwhal10]

🤣🤣🤣

[Narwhal10 in reply to jade_s]

And I second thanking WiscGuy for the discussion. This is exactly what is needed, empowering people with information. Therefore, WiscGuy, the date of the research you post does not matter.

My replies are because clinicians have to show that they are up to date with research when reapplying for registration. When a patient is informed and can hand over a piece of literature to a health professional, it is a case of, ‘I am an informed patient.’ Whether the clinician accepts the document is another case entirely. Some will say, ‘Thanks, I did not realise, I’ll read more about this.’

Others will screw the thing up and throw it in the bin. It really is a case of the attitude of the recipient.

There are articles which are classic. They have been replicated, are robust and so are set in stone. Therefore, the date of the research can be 1897. An example is Ivan Pavlov’s salivating dogs. He also did other great works in gastroenterology including trypsinogen (a pancreatic enzyme).

pubmed.ncbi.nlm.nih.gov/308...

All the best

🐳

[jade_s]

Wow great article, thanks for sharing. It will take some time to read and digest lol.

[WiscGuy in reply to jade_s]

Jade, if you are referring to the article I posted the link to at the top of this thread, please note that the article is from 2001, and so some things referred to in the article could have been supplanted by more recent research.

[jade_s in reply to WiscGuy]

Thanks for the warning I saw that quite a few papers had cited it but no time to go through them yet 😂