There are a number of explanations for its occurrence, including activation of NMDA receptors leading to calcium entering the cell. After the burst of activity, the blood flow to the cerebral cortex in the area affected is decreased for two to six hours. It is believed that when depolarization travels down the underside of the brain, nerves that sense pain in the head and neck are triggered. Pain
The exact mechanism of the head pain which occurs during a migraine episode is unknown. Some evidence supports a primary role for central nervous system structures (such as the brainstem and diencephalon), while other data support the role of peripheral activation (such as via the sensory nerves that surround blood vessels of the head and neck). The potential candidate vessels include dural arteries, pial arteries and extracranial arteries such as those of the scalp. The role of vasodilatation of the extracranial arteries, in particular, is believed to be significant. Neuromodulators
Adenosine, a neuromodulator, may be involved. Released after the progressive cleavage of adenosine triphosphate (ATP), adenosine acts on adenosine receptors to put the body and brain in a low activity state by dilating blood vessels and slowing the heart rate, such as before and during the early stages of sleep. Adenosine levels have been found to be high during migraine attacks. Caffeines role as an inhibitor of adenosine may explain its effect in reducing migraine.
Temporal arteritis typically occurs in people over 50 years old and presents with tenderness over the temple, cluster headache presents with one-sided nose stuffiness, tears and severe pain around the orbits, acute glaucoma is associated with vision problems, meningitis with fevers, and subarachnoid hemorrhage with a very fast onset. Tension headaches typically occur on both sides, are not pounding, and are less disabling.Those with stable headaches that meet criteria for migraines should not receive neuroimaging to look for other intracranial disease. This requires that other concerning findings such as papilledema (swelling of the optic disc) are not present. People with migraines are not at an increased risk of having another cause for severe headaches. Prevention
Preventive treatments of migraine include medications, nutritional supplements, lifestyle alterations, and surgery. Prevention is recommended in those who have headaches more than two days a week, cannot tolerate the medications used to treat acute attacks, or those with severe attacks that are not easily controlled. Recommended lifestyle changes include stopping tobacco use and reducing behaviors that interfere with sleep.The goal is to reduce the frequency, painfulness, and duration of migraine episodes, and to increase the effectiveness of abortive therapy. Another reason for prevention is to avoid medication overuse headache. This is a common problem and can result in chronic daily headache. Medication
Preventive migraine medications are considered effective if they reduce the frequency or severity of the migraine attacks by at least 50%.