Excellent news for migraines sufferers

New hope for migraines sufferers

This is my third blog on migraines. Before we see that new research let us see some basic info about migraines.

What is migraine?

This is a severe, painful headache that is often preceded or accompanied by sensory warning signs such as flashes of light, blind spots, tingling in the arms and legs, nausea, vomiting, and increased sensitivity to light and sound. The excruciating pain that migraines bring can last for hours or even days.

 

Why migraine?

Migraine headaches result from a combination of blood vessel enlargement and the release of chemicals from nerve fibers that coil around these blood vessels. During the headache, an artery enlarges that is located on the outside of the skull just under the skin of the temple (temporal artery). This causes a release of chemicals that cause inflammation, pain, and further enlargement of the artery.

What causes migraines?

Some people who suffer from migraines can clearly identify triggers or factors that cause the headaches, but many cannot. Potential migraine triggers include:

Allergies and allergic reactions

Bright lights, loud noises, and certain odors or perfumes

Physical or emotional stress

Changes in sleep patterns or irregular sleep

Smoking or exposure to smoke

Skipping meals or fasting

Alcohol

Menstrual cycle fluctuations, birth control pills, hormone fluctuations during menopause onset

Tension headaches

Foods containing tyramine (red wine, aged cheese, smoked fish, chicken livers, figs, and some beans), monosodium glutamate (MSG), or nitrates (like bacon, hot dogs, and salami)

Other foods such as chocolate, nuts, peanut butter, avocado, banana, citrus, onions, dairy products, and fermented or pickled foods.

Triggers do not always cause migraines, and avoiding triggers does not always prevent migraines.

What are the symptoms of migraine?

Symptoms of migraine can occur a while before the headache, immediately before the headache, during the headache, and after the headache. Although not all migraines are the same, typical symptoms include:

Moderate to severe pain, usually confined to one side of the head, but switching in successive migraines

Pulsing and throbbing head pain

Increasing pain during physical activity

Inability to perform regular activities due to pain

Nausea

Vomiting

Increased sensitivity to light and sound

How is migraine diagnosed?

Physicians will look at family medical history and check the patient for the symptoms described above in order to diagnose migraine. The International Headache Society recommends the "5, 4, 3, 2, 1 criteria" to diagnose migraines without aura. This stands for:

5 or more attacks

4 hours to 3 days in duration

At least 2 of unilateral location, pulsating quality, moderate to severe pain, aggravation by or avoidance of routine physical activity

At least 1 additional symptom such as nausea, vomiting, sensitivity to light, sensitivity to sound.

Tests such as electroencephalography (EEG), computed tomography (CT), magnetic resonance imaging (MRI), and spinal tap may also be performed that check for:

Bleeding within the skull

Blood clot within the membrane that covers the brain

Stroke

Dilated blood vessel in the brain

Too much or too little cerebrospinal fluid

Inflammation of the membranes of the brain or spinal cord

Nasal sinus blockage

Postictal headache (after stroke or seizure)

Tumors

Difference between migraines and headaches

Basic headache is usually just a pain in the head, neck, and/or eyes. One may or may not feel a little nauseous. They're usually knocked out with some Ibuprofen or Naproxen (Aleeve), and a little rest.

Migraines are a type of headache where the blood vessels that are located in one's brain are dilated, and are pushing the sensitive nerves in the head. They blood vessels actually pulsate, causing the throbbing feeling in one's head.

Researchers have discovered a new compound that could potentially treat migraines by blocking light sensors in the eyes, according to a study published in the journal Nature Chemical Biology. Researchers from the Salk Institute for Biological Studies have found that a series of compounds called opsinamides can block a receptor in the eye called melanopsin - a receptor found in neurons connecting the eyes and the brain. The researchers discovered 10 years ago that melanopsin is responsible for sensing light on its own, away from normal vision. Continued research found that this receptor is responsible for maintaining sleep cycles and various other sensitivity functions in those with healthy vision.

The receptor was also found to be responsible for constricting the pupil within the eye when it is exposed to bright light, triggering the light-sensitivity that is commonly linked to migraines. The receptor also picks up on light-sensitivity as we sleep, explaining why sleep patterns can be disrupted if exposed to artificial light during the night. From this discovery, the researchers believed that if they could find a way to block melanopsin, treatments could be created to prevent and treat migraines. However, there are other receptors that are closely related to melanopsin - rhodopsin and cone opsins - which are responsible for processing visual information to the brain. Therefore, the researchers needed to create a drug that blocked melanopsin but did not interfere with the other receptors.

Opsinamides successful in mice study

For their latest study, the researchers analyzed hundreds of chemicals from the Lundbeck library to see whether each chemical would block melanopsin, and they measured the calcium levels when the receptors were exposed to light.

The study authors say that calcium levels increase in melanopsin when it is exposed to light, signifying that the light has been sensed and that a signal is being sent to the pupil of the eye. A series of chemicals - opsinamides - were found to block the increase in calcium, meaning they were stopping melanopsin from becoming active. The opsinamides were also showing no interaction with rhodopsin or cone opsins, so the chemicals were tested on mice to measure the psychological response, as well as the effect on their melanopsins.  When the eyes of the mice were exposed to bright light after being treated with one of the compounds, the pupil of the eye did not shrink in size as normally expected, indicating that the compound was blocking the melanopsin receptor. The opsinamides appeared to have no effect on those mice as they were lacking melanopsin, meaning that the chemicals were specifically targeting this receptor. Additionally, when the compounds were tested on newborn mice, they did not avoid bright light - something newborn mice are known for doing before they have even opened their eyes.

 

Potential treatment for migraines

Satchidananda Panda, associate professor at the Regulatory Biology Laboratory at the Salk Institute and lead author of the study, says that up until now, everything known about melanopsin has been discovered using inactive mice. This research therefore offers a new way to study the compound.  Kenneth Jones, former project head at Lundbeck, adds, the two compounds require further optimization in anticipation of clinical testing but are extraordinarily useful for research purposes and as leads in the discovery process.

The researchers say that one of the co-authors of the study, Jeffrey Spouse, has co-founded a start-up company called Cyanaptic, which will study the compounds further. Panda adds that once these compounds are further examined and developed, they could be useful to many people in different clinical settings, particularly shift-workers who have disrupted sleep patterns and exposure to sunlight when trying to sleep during the day. "There are many people who would like to work when they have migraine pain exacerbated by light," adds Panda. "If these drugs could stop the light-sensitivity associated with the headaches, it would enable them to be much more productive."

(Source- journal Nature Chemical Biology)