Migraine

                                                                            Migraine

Introduction:-

                          Migraine is a chronic neurological disorder characterized by recurrent moderate to severe headaches often in association with a number of autonomic nervous system symptoms. The word derives from the Greek (hemikrania), "pain on one side of the head from  (hemi-), "half", and  (kranion), "skull" Typically the headache is unilateral (affecting one half of the head) and pulsating in nature, lasting from 2 to 72 hours 

Definition:-

                               A migraine headache can cause intense throbbing or a pulsing sensation in one area of the head and is commonly accompanied by nausea, vomiting, and extreme sensitivity to light and sound. Migraine attacks can cause significant pain for hours to days and be so severe that all you can think about is finding a dark, quiet place to lie down. Some migraines are preceded or accompanied by sensory warning symptoms (aura), such as flashes of light, blind spots, or tingling in your arm or leg.

Mechanism:-

                        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.

A migraine headache causes the sympathetic nervous system to respond with feelings of nausea diarrhea , and vomiting. This response also delays the emptying of the stomach into the small intestine (affecting food absorption), decreases blood circulation (leading to cold hands and feet), and increases sensitivity to light and sound

Types of Migraine:-.

Cluster Headaches

Does severe headache pain attack  in cycles it is a cluster headaches.

Ocular Migraines

Ocular migraines cause vision loss or blindness lasting less than an hour, along with or following a migraine headache.

Sinus Headaches

In it Itchy or watery eye .pain associated with  movement and stuffy nose

Hemicrania Continua

Hemicrania continua, or continuous headache, is a rare type of headache that doesn't stop. 

Status Migrainosus

A migraine headache can last for a few hours a day to several hours. But a migraine attack that lasts for more than 72 hours is called status migrainosus.

Factors which can trigger Migraine:-

§  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

Ø There are 4 phases of Sign and symtoms:-

        Prodrome phase:- , it is occurs hours or days before the headache

 Aura phase:- it is immediately precedes the headache

                        Pain phase:- also known as headache phase

                        Postdrome:-  the effects experienced following the end of a migraine attack

Prodromal or premonitory symptoms occur in ~60% of those with migraines with an onset of two hours to two days before the start of pain or the aura. These symptoms may include a wide variety of phenomena  including: altered mood, irritability,depression or euphoria, fatigue, craving for certain food, stiff muscles (especially in the neck), constipation or diarrhea, and sensitivity to smells or noise. This may occur in those with either migraine with aura or migraine without aura.

 Aura phase An aura is a transient focal neurological phenomenon that occurs before or during the headache^. They appear gradually over a number of minutes and generally last fewer than 60 minutes. Symptoms can be visual, sensory or motor in nature and many people experience more than one. Visual effects occur most frequently; they occur in up to 99% of cases and in more than 50% of cases are not accompanied by sensory or motor effects^. Vision disturbances often consist of a scintillating scotoma (an area of partial alteration in the field of vision which flickers and may interfere with a person's ability to read or drive.)These typically start near the center of vision and then spread out to the sides with zigzagging lines which have been described as looking like fortifications or walls of a castle. Usually the lines are in black and white but some people also see colored lines. Some people lose part of their field of vision known ahemianopsia while others experience blurring.

Sensory aurae are the second most common type; they occur in 30–40% of people with auras. Often a feeling of pins-and-needles begins on one side in the hand and arm and spreads to the nose-mouth area on the same side. Numbness usually occurs after the tingling has passed with a loss of position sense. Other symptoms of the aura phase can include: speech or language disturbances,world spinning, and less commonly motor problems. Motor symptoms indicate that this is a hemiplegic migraine, and weakness often lasts longer than one hour unlike other auras.

 An aura rarely occurs without a subsequent headache, known as a silent migraine. However, it is difficult to assess the frequency of such cases, because patients who do not experience symptoms severe enough to drive them to seek treatment, may not realise that anything special is happening to them, and pass it off without reporting anything.

Pain phase

Classically the headache is unilateral, throbbing, and moderate to severe in intensity. It usually comes on gradually and is aggravated by physical activity.In more than 40% of cases however the pain may be bilateral, and neck pain is commonly associated. Bilateral pain is particularly common in those who have migraines without an aura. Less commonly pain may occur primarily in the back or top of the head. The pain usually lasts 4 to 72 hours in adults however in young children frequently lasts less than 1 hour. The frequency of attacks is variable, from a few in a lifetime to several a week, with the average being about one a month

The pain is frequently accompanied by nausea, vomiting, sensitivity to light, sensitivity to sound, sensitivity to smells, fatigue and irritability. In a basilar migraine, a migraine with neurological symptoms related to the brain stem or with neurological symptoms on both sides of the body common effects include: a sense of the world spinning, light-headedness, and confusion. Nausea occurs in almost 90% of people, and vomiting occurs in about one-third. Many thus seek a dark and quiet room.Other symptoms may include: blurred vision, nasal stuffiness, diarrhea, frequent urination, pallor, or sweating.Swelling or tenderness of the scalp may occur as can neck stiffness^. Associated symptoms are less common in the elderly.

 Postdrome

The effects of migraine may persist for some days after the main headache has ended; this is called the migraine postdrone. Many report a sore feeling in the area where the migraine was, and some report impaired thinking for a few days after the headache has passed. The patient may feel tired or "hung over" and have head pain, cognitive difficulties, gastrointestinal symptoms, mood changes, and weakness. According to one summary, "Some people feel unusually refreshed or euphoric after an attack, whereas others note depression and malaise.

Treatment:-

There are two types of medication

·         Pain relievers. Aspirin, or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin IB, others), may help relieve mild migraines.Pain relievers, such as acetaminophen (Tylenol, others), also may help relieve mild migraines in some people.

Drugs marketed specifically for migraines, such as the combination of acetaminophen, aspirin and caffeine (Excedrin Migraine), also may ease moderate migraine pain, but aren't effective alone for severe migraines.

If taken too often or for long periods of time, these medications can lead to ulcers, gastrointestinal bleeding and medication-overuse headaches.

The prescription pain reliever indomethacin may help thwart a migraine headache and is available in suppository form, which may be helpful if you're nauseated.

·         Triptans. Many people with migraine attacks use triptans to treat their migraines. Triptans work by promoting constriction of blood vessels and blocking pain pathways in the brain.

Triptans effectively relieve the pain and other symptoms that are associated with migraines.

Medications include sumatriptan (Imitrex), rizatriptan (Maxalt), almotriptan (Axert), naratriptan (Amerge), zolmitriptan (Zomig), frovatriptan (Frova) and eletriptan (Relpax). Some triptans are available as nasal sprays and injections, in addition to tablets.

Side effects of triptans include nausea, dizziness, drowsiness and muscle weakness. They aren't recommended for people at risk of strokes and heart attacks.

A single-tablet combination of sumatriptan and naproxen sodium (Treximet) has proved to be more effective in relieving migraine symptoms than either medication on its own.

·         Ergots. Ergotamine and caffeine combination drugs (Migergot, Cafergot) are less effective than triptans. Ergots seem most effective in those whose pain lasts for more than 48 hours.

Ergotamine may cause worsened nausea and vomiting related to your migraines and other side effects, and it may also lead to medication-overuse headaches.

Dihydroergotamine (D.H.E. 45, Migranal) is an ergot derivative that is more effective and has fewer side effects than ergotamine. It's available as a nasal spray and in injection form. This medication may cause fewer side effects than ergotamine and is less likely to lead to medication-overuse headaches.

·         Anti-nausea medications. Because migraines are often accompanied by nausea, with or without vomiting, medication for nausea is appropriate and is usually combined with other medications. Frequently prescribed medications are chlorpromazine, metoclopramide (Reglan) or prochlorperazine (Compro).

·         Opioid medications. Opioid medications containing narcotics, particularly codeine, are sometimes used to treat migraine headache pain for people who can't take triptans or ergot. Narcotics are habit-forming and are usually used only as a last resort.

·         Glucocorticoids (prednisone, dexamethasone). A glucocorticoid may be used in conjunction with other medications to improve pain relief. Because of the risk of steroid toxicity, glucocorticoids shouldn't be used frequently.

Preventive medications
You may be a candidate for preventive therapy if you have four or more debilitating attacks a month, if attacks last more than 12 hours, if pain-relieving medications aren't helping, or if your migraine signs and symptoms include a prolonged aura or numbness and weakness.

Preventive medications can reduce the frequency, severity and length of migraines and may increase the effectiveness of symptom-relieving medicines used during migraine attacks.

Your doctor may recommend that you take preventive medications daily, or only when a predictable trigger, such as menstruation, is approaching.

In most cases, preventive medications don't stop headaches completely, and some drugs cause serious side effects. If you have had good results from preventive medicine and your migraines are well controlled, your doctor may recommend tapering off the medication to see if your migraines return without it.

To prevent or reduce the frequency of your migraines, take these medications as your doctor recommends:

·         Cardiovascular drugs. Beta blockers, which are commonly used to treat high blood pressure and coronary artery disease, may reduce the frequency and severity of migraines.

The beta blockers propranolol (Inderal La, Innopran XL, others), metoprolol tartrate (Lopressor) and timolol (Betimol) have proved effective for preventing migraines. Other beta blockers are also sometimes used for treatment of migraine. You may not notice improvement in symptoms for several weeks after taking these medications.

If you're older than age 60, use tobacco, or have certain heart or blood vessel conditions, doctors may recommend you take alternate medications instead of beta blockers.

Another class of cardiovascular medications (calcium channel blockers) used to treat high blood pressure and keep blood vessels from becoming narrow or wide, also may be helpful in preventing migraines and relieving symptoms from migraines. Verapamil (Calan, Verelan, others) is a calcium channel blocker that may help you.

In addition, the angiotensin-converting enzyme inhibitor lisinopril (Zestril) may be useful in reducing the length and severity of migraines.

Researchers don't understand exactly why these cardiovascular medications prevent migraine attacks.

·         Antidepressants. Certain antidepressants help to prevent some types of headaches, including migraines. Tricyclic antidepressants may be effective in preventing migraines. You don't have to have depression to benefit from these drugs.

Tricyclic antidepressants may reduce the frequency of migraine headaches by affecting the level of serotonin and other brain chemicals. Amitriptyline is the only tricyclic antidepressant proved to effectively prevent migraine headaches. Other tricyclic antidepressants are sometimes used because they may have fewer side effects than amitriptyline.

These medications can cause dryness of mouth, constipation, weight gain and other side effects.

Another class of antidepressants called selective serotonin reuptake inhibitors hasn't been proved to be effective for migraine headache prevention.

However, research suggests that one serotonin and norepinephrine reuptake inhibitor, venlafaxine (Effexor XR), may be helpful in preventing migraines.

·         Anti-seizure drugs. Some anti-seizure drugs, such as valproate sodium (Depacon) and topiramate (Topamax), seem to reduce the frequency of migraine headaches.

In high doses, however, these anti-seizure drugs may cause side effects. Valproate sodium may cause nausea, tremor, weight gain, hair loss and dizziness. Valproate products should not be used in pregnant women for prevention of migraine headaches. Topiramate may cause diarrhea, nausea, weight loss, memory difficulties and concentration problems.

·         OnabotulinumtoxinA (Botox). OnabotulinumtoxinA (Botox) has been shown to be helpful in treating chronic migraine headaches in adults.

During this procedure, injections are made in muscles of the forehead and neck. When this is effective, the treatment usually needs to be repeated every 12 weeks.

·         Pain relievers. Taking nonsteroidal anti-inflammatory drugs, especially naproxen (Naprosyn), may help prevent migraines and reduce symptoms.