Migraine headache is caused by enlargement of blood vessels and the release of chemicals from nerve fibers that coil around the blood vessels. It is a form of vascular headaches.
During a migraine attack, as they are referred to, the temporal artery located on the temporal bone that makes part of the skull (head) enlarges. This artery lies on the outside of the skull just under the skin of the temple.
Enlargement of the temporal artery stretches the nerves that coil around the artery and cause the nerves to release chemicals. The chemicals cause inflammation, pain, and further enlargement of the artery.
The increasing enlargement of the artery magnifies the pain and thus, headache since pain is localised on the head. The reason for persistence of this migraine headache is that it commonly activates the sympathetic nervous system in the body.
The sympathetic nervous system is often thought of as the part of the nervous system that controls primitive responses to stress and pain.
This nervous system is often considered as the part of the nervous system that controls primitive responses to stress and pain. The increased sympathetic nervous activity in the intestine causes nausea, vomiting, and diarrhoea.
Sympathetic activity also delays emptying of the stomach into the small intestine and thereby prevents oral medications from entering the intestine and being absorbed.
The impaired absorption of oral medications is a common reason for the ineffectiveness of medications taken to treat migraine headaches.
The increased sympathetic activity also decreases the circulation of blood, and this leads to paleness of the skin as well as cold hands and feet.
The increased sympathetic activity also contributes to the sensitivity to light and sound sensitivity as well as blurred vision.
Symptoms of migraines
In most cases, migraine headaches are a chronic condition of recurrent attacks.
Migraine headaches are usually described as an intense, throbbing and pounding pain that involves one side of the head. But sometimes the pain can be located in the forehead, around the eye, and the back of the head.
As mentioned, the pain usually is unilateral, meaning it is localised on one side of the head, although about a third of the time the pain is bilateral. The unilateral headaches typically change sides from one attack to the next.
In fact, unilateral headaches that always occur on the same side should alert the doctor to consider a secondary headache for example one caused by a brain tumor.
Briefly, we can say that migraine headache usually is aggravated by daily activities like walking upstairs. Nausea, vomiting, diarrhoea, facial pallor, cold hands, cold feet, and sensitivity to light and sound commonly accompany migraine headaches.
As a result of this sensitivity to light and sound, migraine sufferers usually prefer to lie in a quiet, dark room during an attack. In complicated migraine problem, there’s also the issue of dysfunction in the brain system.
The part of the body that is affected by the dysfunction is determined by the part of the brain that is responsible for the headache.
For example Vertebrobasilar migraines are characterised by dysfunction of the brainstem, which is the lower part of the brain that is responsible for automatic activities like consciousness and balance.
The symptoms of vertebrobasilar migraines include fainting, vertigo such as dizziness in which the environment seems to be spinning and double vision.
Hemiplegic migraines are characterized by paralysis or weakness of one side of the body, mimicking a stroke. This condition is temporally but sometimes can last for days.
A migraine trigger is any factor that causes a headache in individuals who are prone to develop headaches. Only a small proportion of migraine sufferers clearly can identify causes of their problem.
Examples of some of the causes include stress, sleep disturbances, fasting, hormones, bright or flickering lights, odours, cigarette smoke, alcohol, aged cheeses, chocolate, monosodium glutamate, nitrites, aspartame, and caffeine.
For some women, the decline in the blood level of oestrogen during the onset of menstruation is a trigger for migraine headaches. The interval between exposure to a trigger and the onset of headache varies from hours to two days.
However it should be noted that exposure to a trigger does not always lead to a headache. Different migraine sufferers respond to different causes, and any one cause will not induce a headache in every person who has migraine headaches.
Treatment and prevention
Treatment that does not involve medications can provide symptomatic and preventative therapy. Relaxation techniques may be helpful at stopping an attack once it has started. If possible, sleep is the best medicine. Preventing migraine takes motivation for the patient to make some life changes.
Patients are educated as to triggering factors that can be avoided. These include smoking cessation, avoiding certain foods especially those high in tyramine, an amino acid such as sharp cheeses and those containing sulphites such as wines, even nitrates such as nuts, pressed meats.
Generally, leading a healthy life style with good nutrition, adequate water intake, sufficient sleep and exercise may be useful for Migraine headache prevention. For therapeutic treatment, patients with migraine are treated with pain killers and other non-steroidal inflammatory drugs.
The writer is a medical practitioner.