Sunday, 7 July 2013

Wimbledon in the Heat

Can you imagine if Andy Murray had had optic neuritis? #MSBlog #MSResearch

"Andrew Murray will be playing in the Wimbledon final today in temperatures above 30 degrees celsius. His core body temperature will rise above 39 degrees celsius. If Andrew Murray had previously had an episode of optic neuritis he would be in trouble because of the temperature."

"When a demyelinating MS lesion in the optic nerve recovers, it doesn't get back to normal. On average about 20% of the nerve fibres are lost with an episode of optic neuritis. Those nerve fibres that survive and are remyelinated don't conduct as quickly as normal fibres and are susceptible to block (failed conduction) when the core body temperature rises."

"The delay in conduction between the abnormal nerve and the normal nerve causes the brain to misinterpret the visual inputs and results in abnormal depth perception; this is called the Pulfrich effect. If Andy Murray had had a previous episode of optic neuritis as he got hotter and the conduction velocity in the affected eye got longer he would start misjudging depth and would start mishitting the ball. He would lose."

A pendulum swinging in 2D
"With abnormal depth perception you interpret a pendulum swing in 2D (x and y axis) as moving into the z-plane or having depth. MSers who have had optic neuritis will know what I mean."

"3D movie technology is based on the Pulfrich effect; by manipulating the visual inputs into each eye, by filtering different wavelengths of light you fool the brain into interpreting a 2D image as having depth. This works as the nerves transmitting information in relation to different wavelengths, or colours, of light transmit the information at different speeds. Older 3D technology was based on filtering green and red light only; current technology is more sophisticated than that."

"Another phenomenon that occurs as body temperature rises is Uhthoff's phenomenon. This is when the fibres stop conducting with a rise in body temperature and results in visual blurring or the re-emergence of previous blind spot or scotoma. Imaging playing tennis and suddenly you have a blind spot in one of your eyes. This will almost certainly affect your chances of winning."

Uhthoff's phenomenon.

Central scotoma or blind spot.
"Another symptom that MSers complain about after optic neuritis is colour desaturation. The nerve fibres that transmit colour are the most sensitive to damage and it leave the image from that eye washed-out. In most people this is not a problem, but may be handicap if you are an artist."

Colour Desaturation

"Thankfully, we don't play tennis using red balls; the colour that is most affected post optic neuritis. Wimbledon tennis balls are green; a colour that is not entirely immune to the effects of MS."

"Andy Murray does not have MS or optic neuritis so he should be fine and will be able to play at his best today. This can't be said for 100,000+ of his fellow country men and women who live with MS every day. Having MS makes playing tennis at a competitive level very difficult."

"Good luck Andy Murray!"

Other posts on heat sensitivity:

04 Dec 2012
#MSBlog: More on temperature sensitivity; how temperature blocks conduction in demyelinated axons! ... This is why we need to protect them so that they can remyelinate and correct their temperature sensitivity.".
03 Jun 2012
"As MSers can't control their body temperatures as well as control subjects this has a major impact on the functioning of their nerves that are damaged or remyelinated as they become sensitive to temperature and block or stop ...
25 Apr 2013
More on heat sensitivity or Uhthoff's phenomenon. #MSBlog: More on temperature sensitivity; how temperature blocks conduction in demyelinated axons! Stutzer & Kesselring. Wilhelm Uhthoff: a phenomenon 1853 to 1927.
03 Dec 2012
Would be interesting to know how people notice their sensitivity to temperature? Is it an all over sensitivty or is it something like Erythromelalgia, which causes pain in the feet and hands? Dr. G, the relationship (if there is one) ...

28 Jul 2011
In addition, these ion pumps are optimised to function at a certain temperature, this is why some MS'ers are heat sensitive. "Have you heard of Uhthoff's phenomenon?" Wilhelm Uhthoff (1853-1927) was a famous German ...
14 Mar 2012
Although it is assumed that this heat sensitivity is specific for MS, the evidence for disease specificity is limited. We studied the relationship between fatigue, heat sensitivity, and environmental temperature, and its specificity for ...
26 Nov 2012
CONCLUSION: An exercise-induced increase in core-temperature is associated with increased number and severity of perceived symptoms in heat sensitive MSers. Based on these findings it is expected that heat sensitive ...
22 Aug 2012
"I think the problem with in the field of fatigue is that we still don't know how to measure fatigue or even characterise it; for example mental/cognitive vs. physical (exercised-induced or temperature-sensitivity) or fatigue related .

11 Apr 2011
"I think the problem with in the field of fatigue is that we still don't know how to measure fatigue or even characterise it; for example mental/cognitive vs. physical (exercised-induced or temperature-sensitivity) or fatigue related ...
12 Aug 2012
Simply, unbearable. If this is how MSers feel in more moderate temperatures I really feel for them. I am now more determined than ever to try and do something for MS-related fatigue and heat sensitivity. I have some ideas.


  1. And he's Scottish, too! They invented MS.

      Everyone knows scotsmen are the worst tennis players:-)

  2. Well done Andy and Novak played a great part in an entertaining match

    1. Well done to the British and Irish Lions too!

  3. I really wonder about Uhthoff's Phenomena.
    I really like to take hot (and I mean hot!) baths. No signs of worsening symptoms.
    And even when it is hot outside, not much problems.

    But when I am actually outside in the sun when it is hot, I feel a worsening of some symptoms.

    So: is Uhthoff only limited to heat or is UV-x involved too?

    1. Heat; not aware of UV light having anything to do with it.

  4. What about those who don't have any problems with heat, but have quite significant ones with even mildly cold environments? Haven't seen much on that... I'm sure there are quite a few people with that problem out there...


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