A study shows that experiencing a headaches after eating ice cream is a sign for a sudden change in brain blood flow.
This brain blood flow change will lead to migraine. In the recent US scientist study shows monitored brain blood flow in 13 healthy adults as they sipped ice water through a straw pressed against the upper palate so as to trigger "brain freeze." These transient headaches are trigerred by a sudden increase in blood flow in the brain's anterior celebral artery.
The brain is one of the relatively important organs in the body, and it needs to be working all the time. It's fairly sensitive to temperature, so vasodilation might be moving warm blood inside tissue to make sure the brain stays warm. The skull is a closed structure and the sudden rush of blood could therefore boost pressure and cause pain. The subsequent constriction of the artery may also be a way to reduce pressure in the brain before it reaches dangerous levels.
Brain blood flow changes similar to those seen in brain freeze could be associated with migraines and other types of headaches.