Sunday, October 2, 2022

What is happening in the brain during a migraine?

Some chemicals in the brain become more active, causing parts of the brain to send out confusing signals that cause migraine symptoms.
The precise chemical changes in the brain are unknown; however, something may cause a change in the activity of some brain chemicals, resulting in a migraine attack.
 Glutamate:
 Massive quantities of glutamate, a critical neurotransmitter in the brain, could help explain migraine onset.
 An aberrant release of glutamate into the extracellular space (the space between brain cells) can cause spreading depolarizations or tsunami-like waves of activity that spread across the brain, resulting in a migraine. Glutamate is a neurotransmitter that acts as a signal between nerve cells.
 However, too much glutamate can excite cells and destroy them.
 Dopamine:
 Although the exact cause of migraines is unknown, an imbalance in a brain neurotransmitter is thought to play a role.
 Dopamine is a neurotransmitter that affects movement, emotions, motives, and sensory perceptions, as well as the ability to moderate pain.
 Researchers at the University of Michigan have discovered that dopamine levels in the brain decrease during a migraine attack compared with their baseline level between attacks.
 Additional research is needed to confirm the findings and determine how they may be used to build more effective migraine treatments, according to the researchers.
 Serotonin:
 In people with migraine, serotonin (another neurotransmitter) is low between attacks and spikes during the attack.
Migraine is now classified as a neurological disorder and the sixth most disabling disease in the world, according to the Migraine Research Foundation.
What causes migraines?
Although studies have reported that a migraine is a biological disorder of the brain that causes recurring moderate to severe headaches, the exact cause of it remains unknown.
There are, however, few studies and theories regarding the various causes of migraine caused by malfunctions in brain functions:
 Constriction of the blood vessels:
 When blood vessels in the brain constrict, they can cause pain by direct irritation of the nerve endings or by reducing oxygen supply to nearby tissue leading to a migraine.
 Although some migraines appear to be genetically linked, the underlying cause of migraines remains a mystery.
 According to current research, people with migraine have a more sensitive nervous system than the general population.
 Role of the trigeminal nerve:
 Excitation of a nerve responsible for sensation in the face could be one of the causes. The trigeminal nerve is stimulated by various neurotransmitters.
 As a result, the blood vessels that surround the brain expand and inflame.
 These blood vessels are connected to nerve fibers that send pulsations from the blood vessels back into the brain, where you perceive it as pain.
 This system is vulnerable to being activated repeatedly when there is no good reason in people with a migraine.
 Instead of serving as a protective mechanism, it has evolved into a system that interferes with your ability to function normally in your life.
 Cortical spreading depression:
 According to one widely accepted theory, migraines are caused by rapid waves of brain cell activity crossing the cortex (the thin outer layer of brain tissue), followed by periods of no activity. This phenomenon is known as cortical spreading depression.
 According to evidence, it causes inflammatory and other processes that stimulate pain receptors on the trigeminal nerves.
 This “neurogenic” inflammation and the release of other factors make the receptors and parts of the brain that receive their signals more sensitive, increasing the likelihood of a migraine.
 According to some researchers, migraines begin lower in the brain, in the brainstem, which controls basic functions such as respiration and pain responses, as well as modulates many others, including incoming sensory information.
 According to the theory, if certain areas of the brainstem aren’t working properly or are easily excited, they’re capable of triggering cascades of neurological events, such as cortical spreading depression, which account for migraine’s various symptoms.
 Gray matter (GM) changes:
 Functional imaging studies on people with migraine have revealed changes in several brain GM regions.
 Such GM changes include areas of decreased and increased density, and they are most likely related to pathological substrates associated with this disease.
 Brain lesions:
 According to an American Medical Association study, frequent migraines are associated with an increased risk of brain lesions.
 However, more research is needed to determine whether lesions hurt the health and whether they are caused by migraine attacks.
 Traumatic brain injury:
 It is estimated that between 30 and 90 percent of traumatic brain injuries, such as those sustained in sports, military service, vehicle accidents, falls and domestic abuse, resulting in a post-traumatic headache.
 More than half of people with mild to moderate brain injuries fit the migraine criteria.
 Migraine can impair cognitive function, emotional stability, and social connections.
 Migraine-like symptoms are typical in post-traumatic headaches that do not resolve quickly.
 They are usually more severe and resistant to treatment. Migraine is now one of the top 10 causes of military disability.
 The migraine brain does not get used to repeated stimulations:
 If you flash a light in the eyes of someone who does not have a migraine regularly, their brain will ultimately reduce its response.
 For people with migraine, the brain keeps reacting over and over. This lack of adaptability has been observed with light and sound.
 This may cause people with migraine to use more energy being aware of their surroundings. In principle, an overabundance of a stimulus could result in an attack.
Medical Author: Karthik Kumar, MBBS Medical Reviewer: Pallavi Suyog Uttekar, MD