Causes of Migraine

What we know so far

Dysfunction of the Nervous System Can Cause Migraine

The nervous system of a person with migraine is hypersensitive. It overreacts to stimuli causing a wave of brain activity that leads to a headache and other symptoms.

The trigeminal nerve is involved in attacks for almost all people with migraine. The trigeminal nerve is a network of wiring that attaches to special sensors.

Those sensors are located in our:

  • Facial Skin
  • Mucous Membranes
  • Muscles
  • Tendons
  • Teeth

The Bottom Line: Different People Have Different Causes.

When stimulated, nerves send electrical signals to the brainstem which connect to nerves of the cortex and its covering, the dura.

When the system does not work properly, electrical signals set off a slowly moving wave of electrochemical activity across the surface of the brain. People with migraine may start to experience odd sensations, such as what looks like white sparks (a misfiring of the ocular nerve) followed by an intense pain in some part of the head and concluding with a long period of nausea (activation of the gastrointestinal system) and exhaustion (general inflammation and swelling of the cortex).

This abnormal wave of electrochemical activity Is often stimulated by several different stimuli. These stimuli are irrational signals from other parts of the nervous system, such as stress, irregular sleep, a flashing light, a range of food ingredients, weather changes, and noise. Sometimes the migraine symptoms occur spontaneously, without a trigger.


More Potential Causes

Is It In Our Genes?

The majority of people with migraine are born with a hypersensitive nervous system. It is clear that migraine disease runs in families, but the details of the genetics have been difficult to figure out because it is not associated with just one or two gene mutations. So far, researchers have identified more than 20 irregular chromosome segments associated with migraine. Each potential genetic error affects nerve cells in a different way.

Dysfunction in the Brainstem

The brainstem is a complex intersection of nervous system wiring at the base of our brain. It is here that information collected from all over our bodies congregate in important clusters of cell bodies called nuclei. From the nuclei, new signals are rerouted to other parts of the brainstem and the rest of the brain. Nuclei within the brainstem control pain, stress, balance, mood, sleep and the autonomic system. It is the interaction of nuclei that may explain the wide array of disorders in people with migraine.

Some Migraine Symptoms Just Won’t Go Away

Migraine illness can evolve from an occasional intense event to one of frequent annoying, sometimes debilitating symptoms. One explanation is that with each migraine headache or event, there is an inflammatory reaction. This is partly because migraine illness affects not only nerve cells but the adjacent blood vessels and our immune systems. Although the details of this interaction are not yet known, it is understood that the chemicals that are released from nerve ending cause both blood vessels to swell, contract and become leaky and the immune system to become active. Together they cause inflammation within the brain. Over time, repeated inflammation causes damage and changes to the neural circuitry.

Hormones Play A Role

The final concept is that sex hormones have a profound effect on our nervous system. Migraine is a burden on work productivity, relationships and personal enjoyment of life and it is borne most heavily by women. Young boys and girls are afflicted equally with migraine symptoms, but, with the onset of puberty, there are three times as many female suffering from migraines as males. And the hormonal fluctuations of menopause shifts the balance of symptoms from headaches to feelings of facial and ear pressure, imbalance, body aches, sleep disorders and fatigue.

Traumatic Brain Injury

It is estimated that between 30% to 90% of traumatic injuries to the brain, such as those from sports, military service, car accidents, falls and domestic violence, result in post-traumatic headache. For a significant number of people, this headache disorder can continue for over a year post-injury.

Post-traumatic headache is defined as a secondary headache that develops within 7 days after head trauma (or after regaining consciousness following head trauma). Post-traumatic headache is regarded as chronic when it continues for more than 3 months after the incurrence of the injury, although there is some variation in the defined duration. Nearly 45% of head and neck injuries are accompanied by chronic headache at 6 months. At 1 year, head pain in 20% of individuals becomes permanent.

More than 50% of patients with mild to moderate brain trauma meet the criteria for migraine. The difference between tension type headaches and migraine are that the latter may interfere with cognitive function, emotional stability and social interactions. The characteristics of migraine are common among post-traumatic headaches that do not resolve rapidly. They tend to be more severe and more resistant to treatment.

Migraine is now among the top 10 causes for disability in the the military.