i). An energy demanding more sensitive brain
A useful starting point is to think about the brain’s energy demands. Although the brain accounts for only around two per cent of total body weight, it uses approximately 20 per cent of the body’s energy.
In people living with migraine, the brain is more sensitive to sensory information and environmental change. This heightened sensitivity is largely determined by genetics and means the brain works harder to process everyday experiences consuming more energy. From an evolutionary perspective, this increased alertness may once have offered important survival advantages. Being more sensitive to changes in the environment could have helped our ancestors detect danger more quickly. In today’s world of constant exposure to stimulation, it places additional energy demands on a brain that is already working harder than average.
When energy demands become too great, a migraine attack may develop. It may help to think of it as a protective response when the brain’s energy demands are not being met adequately, inducing a period of forced rest.
ii). Problems with energy production
Each cell in the body has its own energy generator found in a specific part of the cell called mitochondria. Research suggests that the mitochondria in people with migraine may be less efficient at generating energy adding to the energy problem.
iii). Problems with chronic or persistent inflammation
Inflammation is the body’s way of protecting itself after injury or infection, triggering complex defensive and repair mechanisms. However, this system can be activated by a wide range of stressors that would not have been experienced when the inflammatory mechanisms were developed during our early evolution (see Figure 2).
