Wednesday, 13 March 2013

Do we have a blind spot?

"I read an interesting article on my way to work this morning; for those of you who don't know I commute by Tube  or the London Underground to work. My journey takes ~45 minutes, which gives me  time to read.  The article was on overcoming blind spots! Neurologists call blind spots scotomas. Many MSers have visual scotomas as a result of optic neuritis; i..e you fail to recover vision in an area that is typically in the center or just off the center of vision. Eye doctors call these central or paracentral scotomas."

"This article was interesting in that it is referring to attentional scotomas or inattentional blindness."

Lisa Rosenbaum. The Whole Ball Game — Overcoming the Blind Spots in Health Care Reform. N Engl J Med 2013; 368:959-962.

...... In 1999, psychologists Daniel Simons and Christopher Chabris published the results of a now-famous experiment. Study participants were shown a video in which two teams of three persons each, one dressed in black and the other in white, revolved around each other and passed basketballs to their teammates. The participants were told to count the number of passes among the players in white. During the video, a woman in a gorilla suit walked across the screen pounding her chest, remaining there for 5 seconds. When the video ended, the participants were asked whether they noticed anything unusual. Consistently, about 50% failed to notice the gorilla.1 Since the participants were focusing only on the white team's passes, most or all of them probably also missed other elements that were much more mundane than the gorilla — such as whether the black team made more or fewer passes than the white team and the pattern or strategy of the game.

But even more striking than what was missed was the resistance of the participants to the possibility that they could have missed something as obvious as a gorilla. Indeed, when shown the video a second time, some even insisted that the experimenters were tricking them and had substituted a different video.

This tendency to lose oneself in specific stimuli at the cost of not seeing other things that are right before one's eyes has been termed inattentional blindness. The mind can attend to only so much information at once. When we focus our attention in one direction, other obvious stimuli may not register. This tendency helps explain why, for instance, driving while talking on a hands-free cell-phone device is no safer than driving with a cell phone in hand: the danger lies in the occupation not of one's hands, but one's mind. Simons and Chabris call the refusal to acknowledge that one has such blind spots “the illusion of attention” and note, “The idea that we can look but not see is flatly incompatible with how we understand our own minds, and this mistaken understanding can lead to incautious or overconfident decisions.”

The concept of inattentional blindness has broader implications for human cognition in terms of the limits of our attention, the power of our expectations, and our reluctance to question our existing beliefs when we receive new information. So perhaps it can help us understand the blind spots in our national health care narrative and the difficulty of acknowledging their existence.......

"Attentional scotomas or inattentional blindness is something researchers in the field of MS are suffering from, me included. We are ignoring glaring ambiguities in the MS data set that is telling us something fundamental about the cause of MS. This is why the field is right for a paradigm shift. I am convinced that MS is not an autoimmune disease, this is not to say the immune system is not involved in MS it clearly is. What we need to find out is what the immune system is responding to. This is easier said than done!"

"I think we should be focusing on the rebound activity that occurs post-natalizumab therapy. Natalizumab is a very effective therapy that switches off focal inflammation in MSers; i.e. it stops relapses and MRI activity. However, when you remove the drug and allow  the immune cells to re-traffic into the brain and spinal cord they find something in the brains of MSers that causes the disease to come back with a vengeance. Why? The immune system must be finding and responding to the cause of MS. What is it? In my opinion it is probably a virus. Which is why the Charcot Project is so close to my heart!" 

Posts of interest on rebound activity:

01 Dec 2012
"The potential rebound in MS disease activity that is commonly seen after withdrawal of natalizumab, and now fingolimod, reminds me of the book 'Waiting for the Barbarians' by JM Coetzee, which I read as a teenager.
27 Jul 2012
Rebound in MS disease activity on fingolimod withdrawal. Epub: Hakiki et al. Withdrawal of fingolimod treatment for relapsing-remitting multiple sclerosis: report of six cases. Mult Scler. 2012 Jul. The objective of this study is to ...
19 Feb 2012
Rebound of disease activity after withdrawal of fingolimod (FTY720) treatment. Arch Neurol. 2012;69:262-4. BACKGROUND: The oral sphingosine-1-phosphate receptor modulator fingolimod (FTY720/Gilenya) was recently ...
31 Dec 2012
"The level of rebound activity can be very severe!" Objective: This study assessed the recurrence of clinical disease activity during the first year after switching from Nz to fingolimod (Fingo) in RRMSers. Methods: The number ...

31 Oct 2012
Natalizumab dramatically reduces relapses in MSers with active MS, but it may induce progressive multifocal leukoencephalopathy (PML).(1) A rebound of MS or an immune reconstitution inflammatory syndrome (IRIS) were ...
30 Oct 2012
Clinical and/or MRI signs suggestive of disease rebound were observed in three MSers. ... "These studies and case reports confirm mine and many other neurologists' observations of rebound on natalizumab withdrawal.


  1. Excellent post. Commonsense stuff regarding the re-bound after stopping Tysabri. I've had Alemtuzumab - no rebound after 5 years after last infusion. Any thoughts on why not - the virus is still there - Alemtuzumab, as I understand it, just re-sets the immune system?

    Grateful for an update on the Charcot Project. Would I still benefit from the drug being used given that I appear to be in remission?

  2. Similar study to the basketball player video, but regarding radiologists and CT scans:

  3. Wonderful post; one of the best in recent weeks. The blog was becoming boring until today. Please keep it up! More of what you think and less dross!

    1. Ditto; best post in weeks.

  4. Has the virus affected the immune system so that it sees danger in the CNS when there isn't any,or is the virus hiding in the CNS and the immune system is acting normally by attacking the virus wherever it is- even in CNS cells?
    Alemtuzumab doesn't stop the immune system getting into the CNS, just depletes/wipes out the baddies, and the new cells don't attack the CNS. Why don't they get re infected with the virus and turn bad again?


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