Migraine is a complex neurological disorder that comes in 4 phases. It consists of the premonitory phase, followed by the aura phase, headache phase and postdrome phase. The premonitory phase typically occurs 60-72 hours before the headache.
Premonitory symptoms include: fatigue, photophobia, confusion, stiffness and loss of appetite, and some of the various trigger factors of migraines are emotional stress and hormonal imbalances.
The female sex hormone, estrogen is responsible for the more frequent migraines in females. When estrogen levels are increased, the body’s painkillers respond more potently, exacerbating a painful experience. This is why some women experience their first migraines during early pregnancy and then find relief after the first trimester.
The second phase of migraines is the aura phase. Typically, there are 4 types of auras: the visual aura (blurred vision or occurrences of zig-zag lines within vision), the sensory aura (tingling sensation on either side of the face, or at a limb), language aura(difficulty with speech) and motor aura (weakness on one-side of the face or upper limb).
These auras are caused by a phenomenon called cortical spreading depression. Its name originates from the cerebral cortex, also known as the outer neurological part of the brain.
Neurons are depolarised and electrical signals are “spread” throughout the outer layer of the brain. These neurons tend to stay depolarised and are believed to be responsible for the aforementioned symptoms.
For patients who do not experience these symptoms, neurological depolarisation may still occur around unconscious areas of the brain and hence, they may not feel like they are present.
The third phase is the headache phase. Patients in this phase may experience nausea, vomiting, photophobia (sensitivity to UV and other light sources) and phonophobia (sensitivity to sound). A few patients may get a condition called cutaneous allodynia, which is sensitivity to touch - certain areas of the skin is hypersensitive and the patient will experience pain even to the slightest touch.
The premonitory phase and the cortical spreading phase activates the trigeminal vascular system, which is the main cause of headaches.
There are 3 branches coming out of the nerve which flare across the face. One of the branches goes out above the forehead and above the eye, this is known as the ophthalmic division. Second, the nerve going around the cheek is called the maxillary division, and the last is called the mandibular division, which lines the jaw and goes around the chin.
The trigeminal nerve covers almost the entire face, this is why patients feel pain no matter where they touch on the face.
The last phase is called the postdrome phase. Also known as the “migraine hangover”, they can linger from hours to days after the headache phase.
The nociceptors or the pain receptors in the brain will get sensitised after a migraine, and will get activated at the slightest stimuli. Hence, patients tend to experience pain over things that will not normally cause them pain such as turning your head or sneezing.
Staying hydrated, getting ample rest and light stretching can help to speed up the recovery of the postdrome phase.
Sources:
https://www.youtube.com/watch?v=MVBNZoEzD1k
https://www.healthline.com/health/hormonal-headaches#TOC_TITLE_HDR_1
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