We have all suffered from a headache at some point in our life. Thus headache is among the most common neurological disorder seen in the out patient neurological clinic. I shall discuss headaches under 2 headings:
1) Primary headaches such as migraines (both common and classical), tension type headache and episodic cluster headaches.
2) Secondary headaches such as headaches associated with brain tumors, temporal arteritis (giant cell arteritis), headaches associated with subarachnoid hemorrhage and meningitis.
1) Migraine: migraine is the most common primary headache disorder. It commonly starts in adolescense and affects women more than men. Migraine is of 2 types:
a) Common Migraine: this is the common variety of migraine in which the headache is not accompanied or preceeded by any aura. Patients usually have complaint of episodic headaches which have a typical character. Headaches are typically unilateral (though the headache may shift from side to side in different episodes) and are accompanied by nausea and vomiting. Patients may complain of dizziness and also usually are sensitive to bright lights and loud sounds at the time of their headache. Sensitivity to loud sounds is called phonophobia and that to bright lights is referred to as photophobia. During an acute attack patients usually feel and look sick and prefer to lie in a quiet dark room. Shaking the head makes the headache worse. Sleep naturally aborts an attack with patients waking up headache free.
b) Classical Migraine: this is migraine with aura. Patients experience an aura at the onset of the headache. The aura is usually visual and patients may complain of seeing bright flashing lights or spots/ halos in front of their eyes (referred to as scintillation scotoma or fortification spectra). Many different types of visual auras have been described, you can see the pictures of some of them by googling scintillation scotoma and looking under images.
2) Cluster headache: this is another type of primary headache disorder which predominantly affects young to middle aged men. Episodic cluster headache is characterized by episodes of intense unilateral headache usually around the peri-orbital area (pain is centered around the eye) associated with nasal congestion, lacrimation (tearing from the eyes) and nasal stuffiness. The headache usually awakens the patient at the same time every day and may be so intensely uncomfortable that some patients have been known to commit sucide. These episodes of daily headache may last for a few weeks and then abate spontaneously only to recur at a later date.
3) Tension type headache: this is a rather common type of primary headache disorder. More commonly seen in women, tension type headache is characterized by holocranial headache (the whole head hurts) or the patient may complain of tightness or a vise like sensation around the head (especially the nape of the neck).
A point to remember is that patients may have 2 or more types of headaches. For example a person suffering from migraine may also admit to having tension type headaches.
Pathophysiology of Migraines: Let us now discuss what causes migraines. The brain itself is insensitive to pain. Let me give a rather crude but effective example. If you take a knife and drive it through the brain, you shall feel no pain. The pain sensitive structures in the brain include the blood vessels which course through the brain, the venous sinuses (think of them as large reservoirs where the venous blood in the brain drains to) and the meninges. The meninges or the covering of the brain are richly supplied by nerves and hence are very sensitive to pain. Thus when one has inflammation of the meninges (condition referred to as meningitis), one has pain in the nape of the neck and headache.
There are many theories to explain the pathophysiology of migraine headaches, the one most accepted is referred to as the trigeminovascular hypothesis. According to this hypothesis, the blood vessels in the brain are innervated by branches of the trigeminal nerve. During a migraine attack, initially the blood vessels constrict (go into a spasm) and then dilate. That is time the patient complains of a throbbing headache, characteristic of a migraine. The pain is referred to the distribution of the trigeminal nerve (this nerve supplies the skin of the face) hence the complaint of pain in the temple and around the eyes. Hence migraine is rightfully thought to be a vascular condition.
The diagnosis of migraine is clinical (that means your doctor shall be able to make the diagnosis without ordering major tests). If there are elements in the history which are atypical for migraine then your doctor may order an imaging study such as an MRI scan of the brain. Usually this is done when there is a suspicion of a brain tumor.
Other atypical signs include:
1) weakness or numbness on one side of the body.
2) new onset headache in the middle aged or elderly.
3) headache associated with projectile vomiting (remember migraine too can be associated with nausea and vomiting).
4) headache which first presented with a seizure.
Once the diagnosis of migraine is secured then the question of treatment arises. There are a couple of aspects in the treatment of migraine which demand attention. The first is the treatment of an acute attack (you are suffering from an acute migraine headache, how to abort the attack and relieve the pain? What medication is the most effective? What if the medicine does not abort the headache attack?).
The second is the prophylatic treatment of migraine (treatment initiated so that you never have the attack in the first place).
There are different medications used to treat the acute attack of migraine and those for prophylatic therapy. I shall discuss them one by one.
Treatment of acute migraine attack:
An acute attack of migraine can be debilitating. Effective treatment which quickly aborts the headache is the need of the hour. Any of the common pain-killers like aspirin, acetaminophen (tylenol), ibuprofen (motrin) is effective in the treatment of an acute migraine attack. The secret for the drug to be effective is that they should be taken right at the onset of the headache. Let me explain, you feel the migraine starting-a dull aching around the eye, the typical aura–if you take the tablet right now then it shall abort your headache. But if you decide to wait and the migraine attack evolves further into a classical unilateral throbbing headache with sensitivity to light and loud sounds, it is more than likely that either the pain killer shall not work or for it to work you shall have to take more than usual amount of the medication (more pills to break the attack). Also remember that most patients during a migraine attack feel nauseous and some may even throw up so it may be hard to keep the pill down.
Now we have more effective and migraine specific medications available. These medications which are commonly referred to as TRIPTANS include medications by the name of sumatriptan (brand name Imitrex), rizatiptan (Maxalt), naratriptan (Amerge, Naramig), zolmitriptan (Zomig), eletriptan (Relpax), almotriptan(Axert, Almogran), and frovatriptan (Frova, Migard). The triptans are 5HT 1D and 1B receptor agonists (meaning that they act on the serotonin receptors in the brain to exert their anti-migraine effects). They are available in the tablet form to be taken orally (by the mouth). Some like sumatriptan can also be administered via the sub-cutaneous route (under the skin) or via the nostril as a spray. This is specially advantageous when the patient is having nausea and is throwing up. Your doctor may prescribe you a triptan. The various triptans differ from one another in their speed of action, side-effects and their efficacy. So if you do not have a positive response to one triptan, it is still worthwhile trying out another.
Another medication effective in the treatment of an acute migraine attack is DHE or dihydroergotamine. DHE is usually given intravenously (via a vein) but as compared to the triptans it has more side-effects and hence is not the first choice to treat an acute migraine attack. You may be given this medication if you land up in the emergency room with a bad attack of migraine that has not responded to the conventional pain-killers and triptans.
Other medications which are also effective in treating an acute attack of migraine include the opioids (morphine and codeine containing drugs). We as doctors avoid using these drugs because of their significant addictive potential. Patients may get addicted to their use and then start abusing the drugs.
Prophylatic therapy for migraine attacks: The idea behind migraine prophylaxis is to use a medication which prevents the migraine headache from coming on in the first place. If you can prevent an attack of headache from happening then you do not need to treat it. Makes sense you would say!!!
There are many different classes of drugs which have demonstrated efficacy in migraine prophylaxis. Let us discuss some of them. Some of the commonly used drugs for migraine prophylaxis are those that belong to a class called beta blockers. Drugs included under this class commonly used to treat migraine include Inderal (propanolol). The tricyclic antidepressants are also commonly used and are effective in migraine prophylaxis–drugs such as Elavil (amitriptyline). Recently a number of anti-seizure drugs have demonstrated their efficacy in migraine prevention. Topiramate is one such drug which had gained much popularity in recent years. It is marketed under the brand name Topamax. The calcium channel blockers are also used. A popular drug in this class used for migraine prophylaxis is verapamil.
Changing your lifestyle and identifying your migraine triggers is the key to achieving good control of these disabling headaches. Common migraine triggers are:
1) Lack of sleep
2) Too much sleep–lets assume you normally sleep for 7 hours a night, now one night you oversleep–it is possible you may wake up with a headache.
3) Alcohol intake–migrainers have a more sensitive brain and thus if they drink too much, it can trigger off an attack. They are especially sensitive to red wine and it is best to avoid it.
4) Certain foods act as migraine triggers–commonly implicated are aged cheeses and chocolate.
5) Excessively stimulating environment–example you go to a rock concert: loud music, bright lights, a beer here and there–the perfect migraine combo.
6) STRESS ! STRESS ! STRESS!
Doctors frequently ask their patient’s to maintain a headache diary. This is basically a diary maintained by the patient in which the patient documents each and every headache attack. What precipitated it, what brought on relief from the headache, things eaten around that time etc. If you maintain a good headache diary for a month, you shall be able to identify your migraine triggers and thus avoid them.
SPECIAL TYPES OF MIGRAINE HEADACHES
1) Familial hemiplegic migraine–as the name suggests it is familial, meaning that it runs in the family. In this special type of migraine, patients usually develop episodic hemiplegia (weakness/ numbness on one half of the body) around the time the headache attack occurs. The hemiplegia resolves once the attack of migraine is over. Familial hemiplegic migraine is thought to occur due to vasoconstriction (spasm of the blood vessels of the brain).
2) Retinal artery migraine–as the name suggests, here the migraine process involves the retinal artery and does presents with visual symptomatology.
3) Basilar artery migraine–here the migraine process involves the basilar artery or its branches in the brain-stem. Patients have sign and symptoms reflecting involvement of the artery and superficially it may seem that they are having a stroke.
4) A number of migraine variants have been described in young children. Young children may not have the classical headache, or they may be unable to express that they are having headaches. A few of the migraine variants described in children include:
a) benign paroxysmal vertigo—children have episodic attacks of vertigo and may throw up during an attack.
b) abdominal migraine-children present with episodic abdominal pain.
c) alternating hemiplegia of childhood–here children have weakness which shifts from one side of the body to the other.