The doctor who wrote this paper explains the importance of the emissary veins in thermal regulation. Marie has written on here many times about the importance of venous flow in cooling the brain. Slowed venous return would affect this process, and throw off thermal regulation of the whole body.
The brain is one of the most metabolically active tissues, generating large amounts of heat. Dissipating this heat as well as heat absorbed from the environment has been a major evolutionary hurdle, one that was necessary to overcome for the continued development of the brain and the evolution of humans. Simply put, the brain, like the automobile engine, could not increase in size without the simultaneous development of an adequate cooling system. The brain was constrained and could only develop in parallel to its “cranial radiator” (2). However, for many with multiple sclerosis, the cranial radiator is simply not adequate.
The evolution of emissary veins solved this problem and removed any restraint on brain development. According to this theory, a vascular network in the scalp and face developed with veins draining through emissary veins in the skull joining the meningeal veins and sinuses of the dura mater. From the dura, venous blood drains to veins within the brain, thereby removing heat from the brain. With heat stress, the venous plexus on the face and scalp dilate, promoting heat loss by conduction. In addition, secretomotor pathways activate sweating, further cooling the blood by evaporation. Thus venous blood, the temperature of which is lowered by conduction and evaporation, percolates back to cool the brain (2).
Jeff just got back from a long bike ride in the heat. No more heat intolerence since his venoplasty...before treatment he had to wear cooling vests and hats during LA summers. No longer. Ahd his body temp is 98.6.
Husband dx RRMS 3/07
dx dual jugular vein stenosis (CCSVI) 4/09
dual stents placed 5/09
CCSVI in MS