Posted by Bennie Sue (63.16.4.204) on September 25, 2000 at 18:00:52:
In Reply to: Vascular Musings- -Well Done, Jack! posted by Charlie on September 25, 2000 at 17:10:48:
I can understand dilation and constriction of blood vessels as terminology, but what does that actually have to do with our head pain? Blood vessels do not have nerves in them, do they?
Is the change in blood vessel size what causes us to feel pain? Or is it pressure on surounding tissue?
If I use Imitrex successfully to constrict my blood vessels and get quick relief from an attack, then why do I get a measure of relief from applying extreme heat (which surely is a dilator, isn't it?) I can sometimes soothe the pain by running hot water over my wrists for a period of time. Warmer blood should, it seems to me, dilate rather than constrict blood vessels.This seems contradictory to me.
We have discussed the neurotransmitter, CGRP. It reaches very high levels in the blood vessels of the neck during an attack. We have seen that Imitrex or oxygen use returns the level of CGRP to normal. How does this figure into the dilation/constriction process?