Muliple Sclerosis -- let's talk about sex (well, gender anyway)

by Michael S. Kaplan, published on 2007/12/25 10:01 -05:00, original URI:

It wouldn't be Christmas without a Salt-N-Pepa reference, would it? This blog is not about sexual dysfunction as a symptom of multiple sclerosis, it is about the relationship between gender and incidence of MS...

It is widely reported (and has been almost since Charcot first described MS in for the medical world in the late 1800s) that as a disease it affects women more often than men.

The ratio varies depending on the study, but generally speaking it has been reported as being about a ratio of two females to one male (e.g. from the Wikipedia article):

As observed in many autoimmune disorders, MS is more common in females than males; the mean sex ratio is about two females for every male. In children (who rarely develop MS) the sex ratio may reach three females for each male. In people over age fifty, MS affects males and females equally. Onset of symptoms usually occurs between fifteen to forty years of age, rarely before age fifteen or after age sixty.

And there are some more bits which will contribute to my Christmas day blather:

The initial attacks are often transient, mild (or asymptomatic), and self-limited. They often do not prompt a health care visit and sometimes are only identified in retrospect once the diagnosis has been made based on further attacks. The most common initial symptoms reported are: changes in sensation in the arms, legs or face (33%), complete or partial vision loss (optic neuritis) (16%), weakness (13%), double vision (7%), unsteadiness when walking (5%), and balance problems (3%); but many rare initial symptoms have been reported such as aphasia or psychosis. Fifteen percent of individuals have multiple symptoms when they first seek medical attention. For some people the initial MS attack is preceded by infection, trauma, or strenuous physical effort.


Multiple sclerosis is difficult to diagnose in its early stages. In fact, a definite diagnosis cannot be made until other disease processes (differential diagnoses) have been ruled out and, in the case of relapsing-remitting MS, there is evidence of at least two anatomically separate demyelinating events separated by at least thirty days.


For identical twins, the likelihood that the second twin may develop MS if the first twin does is about 30%. For fraternal twins (who do not inherit an identical set of genes), the likelihood is closer to that for non-twin siblings, or about 4%. This pattern suggests that, while genetic factors clearly help determine the risk of MS, other factors such as environmental effects or random chance are also involved. The actual correlation may be somewhat higher than reported by these numbers as people with MS lesions remain essentially asymptomatic throughout their lives.

Let's take this in slowly.

What have we learned?

Well, for one we know that there are people who can have MS without realizing it -- in fact so many that the numbers for "silent MS" have been estimated at 25% (meaning for every four cases of MS diagnosis there is an additional silent case out there) or more.

For what it's worth, a great number of these silent cases are not found in twin studies with only one twin diagnosed; they are usually found at autopsy done for unrelated reasons. And the incidence of these cases varies though is perhaps about the same between men and women or possibly higher for men (usually discounted due to a larger number of such autopsies having to be done due to some of the questionable ways that men end up dying at times) -- though AFAIK no complete studies have been done to confirm that.

For another, we know that attacks are often transient with symptoms that are not always easy to describe or test for. And that symptoms often appear to vanish given the relapsing/remitting nature of the disease.

And we know that past 50 the sex ratio evens out.

So what do we know about men under 50 that makes them different from women, beyond the obvious?

Well, for one thing there is the likelihood that they will complain to a doctor or indeed anyone when something is wrong even if it is not hard to explain or describe, or even if it is. Men, who don't ask for directions and don't share their feelings and all of those other clichés, are simply less likely to go to a doctor for anything if they can avoid it, all things being equal.

In other words, the marked difference of MS incidence between the sexes based on initial report of symptoms has glaring similarities with the likelihood of members of the two sexes to actually make the initial report.

Back before the MRI, women used to pay a terrible price for their vigilence -- they were often given pyschiatric diagnoses for their trouble, which of course was helped by the tendency of men to assume that hysteria in women was a valid phenomenon....

Shocker. And holy self-fulfilling prophecy, Batman!

So perhaps the "higher incidence of MS in women" hypothesis treated so often as fact should be tested out in a way that will be able to negate the influence of the simple fact that women are more in touch with their bodies and less often willing to avoid seeking help when they perceive that something is wrong.

Please note that this hypothesis of mine is not proof that I am either a woman or gay (the latter being somethig some of the idlers speculate on). Point of fact, I refused to go to the doctor on the first day of clear symptoms that were happening in one leg; it was only on the next day when symptoms had spread to both legs and started in my hands and arms on the sane side as the initial leg symptoms that I was even willing to go to a doctor. Were I not married at the time I might have tried to wait it out, actually (she was more worried than I was since they were just sensory issues that I felt I could ignore).

Any neurologists or doctors or residents or interns or medical students reading here? :-)


All of the characters in Unicode have taken off for Grand Cayman for the Christmas holiday weekend
(they are staying at the Marriott Grand Cayman Beach Hotel in case you are there and are curious at all the characters hanging out by the pool!)

# mdmhvonpa on 26 Dec 2007 11:46 AM:

MS is a scourge in my family (Mother's side) and is very nearly a Female centric problem.  I was the first male in the family diagnosed with the ailment.  Here is the kicker though ... I'm most certainly the first male to ever get an MRI and the first one to assume that my difficulties did not stem from the bottle and heavy farm labor.  I have one blood related uncle and three male cousins.  Two of the cousins are successful drinkers who live in a very rural area.  They will never be diagnosed unlike the 4 female ancestors who have been.

# Michael S. Kaplan on 26 Dec 2007 11:54 AM:

Kind of indirectly shows there could be some merit to my hypothesis....

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