Flatline movement

I’ve just found another video of the Lazarus sign, the spinal reflex that triggers an arm raising and crossing movement in recently brain dead patients.

We’ve covered the mechanism behind the somewhat disconcerting movement before, and have noted an earlier video, but this one seems to have been uploaded quite recently.

The movement is triggered by a reflex arc – a basic neural circuit that doesn’t go any further than the spinal cord which means that it can initiate movement even when the brain is non-functional.

When the doctor taps your knee and causes a knee jerk, he or she is triggering exactly this effect. In fact, these movements can be triggered all over the body.

If you’ve ever had a complete neurological examination the neurologist will tap on various points to trigger numerous reflex arcs to check that the nerves going to and from certain muscle groups are in good working order.

One of these arcs causes the movement in the Lazarus sign, which, needless to say, can be quite disconcerting for doctors and quite confusing for relatives if the patient has just passed way.

In fact, you can see from the video how ‘lifelike’ the movement seems.

Probably not recommended if you’re uncomfortable with the sight of recently dead people moving.
 

Link to video of Lazarus sign.

4 Comments

  1. Posted August 6, 2011 at 1:23 am | Permalink

    …or indeed the SIGHT of dead people moving.
    :D

  2. Posted August 6, 2011 at 1:27 am | Permalink

    Thanks! Now fixed.

  3. Phil Donnelly Rooney
    Posted August 8, 2011 at 4:35 pm | Permalink

    it’s describes=d as a “reflex”. What stimulus evokes it?
    Isit seen only in certain causes of death, e.g. brain injury?
    thankyou

  4. P84
    Posted August 21, 2011 at 3:58 pm | Permalink

    Back when I was a 4th year student in medical school, during a rotation through internal medicine, there was a recently-deceased elderly woman who kept making strange gestures with her mouth. Of course, the doctor with whom I was dissmissed it as reflex activity, but at first glance it did make her seem alive.


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  1. [...] faulty connections, not just a region. This is more preaching than could possibly be salubrious. Probably not recommended if you’re uncomfortable with the sight of recently dead people moving. The taste just kind of lingers in your teeth. So let’s just say the physics community remains [...]

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