Migraine
Migraines are a type of extremely severe headache that can occur periodically over the course of many years. According to the experts at the Mayo Clinic, it is not exactly understood what causes migraine headaches, but it appears to be a mixture of environmental effects and genetics. Some of the current thinking is that migraines are related to disorders of a specific nerve called the trigeminal nerve, as well as changes in the level of a specific neurotransmitter called serotonin. As a neurotransmitter, serotonin allows neurons within the brain to send signals to each other. One of the signaling pathways in which serotonin is involved is the communication of pain.
Migraines and Hypoxia
For many years it was thought that migraines only caused pain, not lasting brain damage. In 2007, however, a research article published in the Nature Neuroscience journal suggested that migraines could cause lasting damage to the brain. This study, which was authored by Dr. Takahiro Takano and was supervised by Dr. Maiken Nedergaard, used two different methods of imaging to look for brain changes in adult mice. The study took place at the University of Rochester Medical Center and examined how a phenomenon called cortical spreading depression correlated with another condition known as hypoxia. Cortical spreading depression is essentially a slowly moving wave of the neurons temporarily not communicating and is thought to be a part of how migraines occur. This study found that cortical spreading depression could cause hypoxia, which is a condition in which cells do not receive enough oxygen, similar to a miniature stroke within the brain.
Hypoxia and Brain Damage
Hypoxia is the mechanism by which strokes and other problems in which blood flow stops causes damage to organs. When blood flow stops, the cells quickly use up the remaining oxygen, leading to low oxygen levels which are also known as hypoxia. Oxygen is a critical part of the system that cells use to generate energy efficiently. As a result, soon after hypoxia occurs, the cells begin to run low on energy. Because many of the processes that the cell uses to survive require massive amounts of energy, a number of changes rapidly occur. One of the earliest signs of hypoxia is swelling of the cell as water begins to enter into the cell to counteract the accumulation of some chemicals, such as sodium inside the cell. This swelling, especially in the brain, can lead to sudden cell death and inflammation as the dead cells trigger responses from the immune system. Because neurons are generally unable to be regrown once they are dead, these small pockets of hypoxia resulting from migraines could result in permanent brain damage.
