Jim,
Convulsing can occur when a part of the brain is shut off from
circulation. 
A shutoff situation can be constituted by a sudden drop in blood
pressure.
A sudden drop in blood pressure can be caused by a temporarily reduced
backflow to the right heart chamber.
This can be caused by a positive intrathoracic pressure provoked by
breathhold when ascending, or strenous work combined with latter, f.i.
trying to cling to an anchor line when there is a strong swell present (
instead of letting the line glide through the fingers and stay at a
constant depth)
..
It (the pressure drop)is a reflectory response to the lack of blood fed
to the right chamber.

I don't know at all if this scheme is relevant to the accident, since I
think someone mentioned the victim was bleeding from the nose ?

When assuming an age for whatever reason, and see the "no damage"
outcome, this may be interpreted as "no apparent damage", in view that
there may be very well a damage, only it escapes the methods of
diagnosis because we seem to have some brain cells to spend without
instant payback.
Just my cross the pond 2cc.
Matthias

Jim Cobb schrieb:
> 
> Doc Grogan & George-
> I am still confused about AGE. Questions:
> -So it is possible to get AGE to the point of passing out but not
> suffer any brain damage?
> -I thought that once the bubble(s) got into the brain it shuts off
> blood flow to that part of the brain.
> -How long can brain cells survive without blood?
> -How percentage of the brain needs to be deprived of blood flow to
> cause a blackout?
> -Once in the brian how long do these bubbles hang around before they
> dissapate?
> -Is this a pole-ax knockout or do you feel symptoms of an AGE coming
> on (nausia, visuals, etc).
> -If there are signs, can you do anything about it to save your ass,
> perhaps descend (with your buddy) an atomosphere or two?
> 
> I suppose everybody who ocean dives has blown the near-surface deco at
> one time or other. This is the one problem I have with George's deco
> profiles, the slow descent from 10' to the surface. More often than
> not this is not doable due to the boat flopping around, currents and
> the rapid expansion of air in your suit/wings in this zone. Perhaps a
> drifting deco is better for this,  but it is not an option in most
> cases up here.
> 
> I have been on my hangline at 30', have the current surge and be swept
> up to 15' or so before I let enough line out to get back to depth. I
> have never thought much about it until this AGE discussion.
--
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