Migraine disease, a neurological disorder characterized by recurrent severe headache attacks, have been a perplexing medical phenomenon for centuries. Migraine research dates back to the Hippocrates and ancient Greek medicine, and yet, there is much that remains to be unraveled.
In the past several decades, innovative researchers have allowed the scientific and medical community to embark on the journey of fully uncovering the underlying mechanisms and exact cause of migraine that 39 million Americans must live with.
By delving into the known mechanisms of the brain during a migraine attack, we seek to understand what happens in the brain during a migraine. In shedding light on the origins and complexities of the brain's most persistent disease, we hope to inspire a greater understanding of how migraines affect individuals differently and pave the way for more effective and targeted treatment approaches.
How It Starts - A Look at the Science Behind a Migraine:
A migraine attack is an extraordinarily complex brain event that takes place over hours to days. To understand migraine, we’ll start by unveiling what the most advanced technology and research reveals about how exactly they originate in the brain.
Today, researchers believe that migraine pain happens due to waves of activity triggered by groups of excitable brain cells, likely significantly impacted by genetic abnormalities. While there are many external triggers, like stress, certain foods, and environmental factors that can contribute to this nervous hyperexcitability, internally, a host of trigger chemicals, such as serotonin, also respond to the excitable neurons and trigger the onset of migraine.
Once a migraine is triggered, the trigeminal nerve, a cranial nerve that controls sensory and pain perception in the face and head, releases neurotransmitters, chemicals that enable neuron communication. These neurotransmitters then bind to specific receptors on the blood vessels in the brain, setting off a chain reaction of events.
The first reaction is vasodilation, which means that the blood vessels in the brain widen. This widening of the blood vessels leads to swelling and inflammation in the surrounding tissues. As a result, proteins from the blood can leak out of the blood vessels, a process called plasma protein extravasation. Concurrently, the trigeminal nerve reactivates during this process. When it becomes activated, it sends pain signals to the brain, and this is what causes the characteristic pain experienced during a migraine.
Migraine Symptoms and Their Origins in the Brain:
During a migraine attack, individuals can experience a host of different symptoms depending on their unique migraine characteristics. Let's dive into some common migraine symptoms and explore their origins in the brain.
- Nausea: Nausea and vomiting are common symptoms that can occur during a migraine attack. The precise mechanisms behind migraine-induced nausea are not fully understood, but researchers believe they involve the nervous system and gut. During a migraine, the nucleus tractus solitarius, cell bodies found in the brain stem that regulate autonomic function, receives and processes sensory pain signals from the trigeminal neurons. This transmission leads to various autonomic symptoms, such as nausea and vomiting.
- Mood Changes: Migraine attacks can often be accompanied by notable changes in mood, ranging from irritability to sadness or anxiety. The release of neurotransmitters and inflammatory substances impacts the limbic system, a region of the brain that plays a crucial role in regulating emotions, causing mood alterations.
- Blurred Vision: Blurred vision is another symptom experienced by roughly 20% of migraineurs during the course of an attack. The origin of this visual disturbance lies in the brain's visual processing centers. Migraine-induced alterations in blood flow and neurotransmitter activity can disrupt the normal functioning of regions in the brain’s visual cortex, leading to symptoms like blurred vision.
- Aura: Aura is a sensory warning sign that can precede or accompany a migraine attack. It often involves visual disturbances, such as flashes of light or blind spots, but can also manifest as tingling sensations in the hands or face. The origins of aura lie in cortical spreading depression (CSD), a phenomenon where waves of neuronal activity spread across the brain's visual cortex. These waves can affect specific sensory regions, leading to the diverse aura symptoms experienced by migraineurs.
The Migraine Cycle and Its Stages
Migraines often follow a predictable cycle, consisting of four main stages: prodrome, aura, headache, and postdrome.
- The prodrome stage may occur hours or even days before a migraine attack and includes subtle warning signs like mood changes, food cravings, or fatigue.
- The aura stage, experienced by approximately 25% of migraneurs, precedes the headache phase and involves visual disturbances and other sensory symptoms. During this phase, there are changes in cortical function, blood flow, and neurovascular coupling. Often, the aura phase overlaps with the headache phase.
- The headache phase is the most debilitating stage of a migraine, characterized by throbbing and intense pain. This phase can last for hours or even days, severely impacting daily activities. During this phase, there are significant changes in blood flow and function of various brain regions, including the brainstem, thalamus, hypothalamus, and cortex.
- Finally, the postdrome stage follows the headache phase, leaving sufferers feeling drained, fatigued, and mentally foggy. Even during postdrome, several brain regions experience persistent changes in blood flow, causing ongoing symtpoms.
Although these phases of migraine have substantial overlap in timing, neurochemical changes, and brain anatomy, each represents an important aspect of migraine pathophysiology and offers potential targets for therapeutic intervention.
Treatments, Triggers, and Takeaways
Managing migraine involves a combination of lifestyle adjustments, identifying triggers, and seeking appropriate treatments. While there is no cure for migraine disease, various medications, therapies, or lifestyle changes can help alleviate symptoms and prevent future attacks.
Potential treatments include over-the-counter pain relievers, prescription medications like triptans, anti-nausea drugs, and preventive medications for chronic migraine. Additionally, alternative therapies like acupuncture, botox, massage therapy, biofeedback, and relaxation techniques may provide relief for some individuals.
Yet your best holistic, sustainable bet is identifying and avoiding your unique triggers, such as certain foods, minimizing stress, avoiding a lack of sleep, and staying hydrated. The American Headache Society suggests keeping a migraine diary can help track triggers and patterns, aiding in the development of personalized management strategies.
As we drive forward scientific and medical innovation in an attempt to unlock the mysteries of migraines, ongoing research is dedicated to better understanding the underlying mechanisms of this neurological disorder. The goal is to develop more targeted and effective treatments, as well as preventive measures, to provide long-term relief and improve the overall quality of life for migraine sufferers.