Is MS more than one disease?

Almost certainly! However the size of this problem may be small or at least is getting smaller.

You may recall my previous post on the history of MS that MS was first described as a disease by the great French neurologist Charcot. Charcot was the first to describe the clinical features in combination with the pathological features of MS at post-mortem. This is the so called “clinicopathological correlate” and is the conventional way of describing a disease in medicine.

(One of the reasons I am taking so much flak for my stance on CCSVI; is that it does not conform to a conventional definition of a disease at the present time.)

As you are aware we cannot apply the conventional definition of MS clinically; it is simply not practical, and too dangerous, to do a biopsy of the brain or spinal cord to confirm the diagnosis of MS. For some diseases, for example brain tumours, the vast majority require a biopsy to make a diagnosis.

Back to MS: we know from post-mortem studies that neurologists are not 100% accurate in making a diagnosis. Unfortunately, we get it wrong about 5% of the time. In other words 1 out of every 20 people who die with a diagnosis of MS have a different disease at post-mortem. You may find this very surprising but MSologists are better than other neurological subspecialties. With Parkinson’s and Alzheimer’s disease neurologists get the diagnosis wrong in up to 20% of cases.

As new diseases that mimic MS get they get excluded from pool of cases that get diagnosed as being MS. Two classic examples of this are:

1. Optic-spinal MS: this is a relatively rare form of MS that is most common in Asia and Japan. The majority of these cases now have a specific antibody that can be detected in their blood that labels them as having a disease that we call neuromyelitis optica or NMO.

2. Tropical spastic paraparesis or HTLV1-associated myelopathy. This disease mimics primary progressive MS and is due to a virus that is distantly related to the HIV virus. Prior to us knowing that this disease was caused by HLTV1 people presenting with this disease in Europe were frequently diagnosed as having MS.

So yes, there may be other MS mimics to be found that in the future will be labelled as being another disease.

Additional reading: HTLV1-associated myelopathy or tropical spastic paraparesis, neuromyelitis optica or NMO

About the author

Prof G

Professor of Neurology, Barts & The London. MS & Preventive Neurology thinker, blogger, runner, vegetable gardener, husband, father, cook and wine & food lover.


  • Re: "the size of this problem may be small or at least is getting smaller."

    Not sure that the rest of your post reflects that statement. If aanything, I get the sense MS is terribly vast and difficult to comprehend.

    Nonetheless, this is an eye-opening bit of info that 1 out of 20 MS cases are erroneous. That's a startling truth.

  • Thank you for this interesting post.

    RE: “One of the reasons I am taking so much flak for my stance on CCSVI; is that it does not conform to a conventional definition of a disease at the present time.)”

    I would say the reason you are ‘taking flak’ for your stance on CCSVI is that you do post some deliberately provocative, sometimes factually incorrect, sometimes only partially true, ‘information’ on the subject.

    Other times you neglect posting more rounded news on the subject. For example, the fact that the Canadian Institutes of Health Research said it was new evidence, not public pressure, which prompted their CCSVI trial.

    These posts are often read by people who have had first-hand experience of the procedure and may have read even wider than you on the subject. I know I did my research before parting with my hard earned.

    On a side note, is a ‘disease’ the same as a ‘medical condition’?

  • It seems that the everyday meaning of 'disease' is not the same as the scientific meaning. I just googled 'heart disease' and learnt that it is actually a 'family of diseases'.
    And with cause of disease: sometimes people who have never smoked get lung cancer. So we should not say that smoking causes lung cancer.

  • Re: "So we should not say that smoking causes lung cancer."

    Yes, we can smoking is one of the causes. If you don't smoke it reduces your chances of getting lung cancer by 85%.

  • Re "'heart disease' and learnt that it is actually a 'family of diseases'"

    Heart disease is a misnomer; a disease is a specific entity. A better term would be "heart diseases", which would then refer to the family of specific diseases that affect the heart.

  • Re: "… is a ‘disease’ the same as a ‘medical condition’?"

    Yes, a disease is a medical condition, but a medical condition is not necessarily a disease. Not all medical conditions are supported by clinicopathological correlates. For example, some symptoms and signs are referred to as medical conditions, but are not diseases.

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