Mind your head
THERE must hardly be any adult who has not experienced a headache in his/her lifetime. In fact, even many of the children are not spared this ordeal. It is estimated that nearly 90 per cent of the people have a headache at least once a year and nearly half of them may experience a severe headache. The good news, however, is that in the vast majority of cases, the headache is benign in nature and only in about 5 per cent cases it may indicate a serious underlying disease like brain tumour, haemorrhage in the brain, meningitis or other disorders.
The head houses the
most complex as well as delicate organ of the body — the brain. The
brain is encased in a well-designed bony cavity with support
structures like strong sheets of facia, three surrounding layers of
meninges with cerebrospinal fluid circulating in between, arteries,
veins and a network of outgoing and incoming nerves. The three
important sense organs — eyes, nose and ears — are intimately
connected and communicate with the brain through the skull. Various
joints in the vicinity, like cervical spine and temporo-mendibular
joint of the jaw, contribute to the functions of the brain and the
neck as well as to the causes of headache. The brain by itself is not
sensitive to pain but pain-sensitive tissues like the scalp, meninges
(covering layers of the brain), arteries, veins and irritation of some
of the nerves can give rise to a severe neurological pain. Spasm or
trauma of the muscles, meningeal irritation and increase in the
intra-cranial pressure can give rise to pain. Often, inflammation of
or increasing pressure in the eye, ear and nose is perceived as a
headache. Considering the vast, sensitive network of structures in
this area, it is surprising that we do not have a headache more often.
Causes of headache
The causes of headache are indeed numerous. The International Society of Headache mentions 13 broad groups and over 60 sub-groups for the etiological classification of headache and individual causes will run into hundreds.
It is important to recognise the nature and quality of a headache right in the beginning. If it persists beyond a certain time-frame, the headache should be taken seriously and investigated thoroughly.
We all recognise the common causes of a headache such as stress, anxiety, depression, fatigue, boredom, frustration, hunger, cold, lack of sleep, noise and air pollution and the pre-menstrual syndrome in women.
There is, however, a group of headaches which are benign but can be very debilitating and recurring. These include various varieties of migrainous headaches. Migraine usually starts around adolescence and goes right through middle age. It is throbbing in nature, may be limited to one half of the head and is often accompanied by nausea or vomiting and sometimes visual disturbances.
This group of headaches is often familial in nature and precipitated by factors like stress, lack of sleep, hunger, noise, flashes of light and menses in women.
Another group of headaches is generated in the surrounding structures of the head. They include any refractory error in the eye or raised pressure in the eye ball known as glaucoma, blocked or inflammed sinuses of the nose, inflammation of the ear, any problem in the cervical spine, temporo-mendibular joint and various dental problems. Low blood glucose (hypoglycemia), low oxygen in the atmosphere like at high altitudes, etc, all can produce a headache. Repeated paroxysmal cough can also cause a severe headache.
It is a common public perception that high blood pressure is a common cause of headache. There is no doubt that very high blood pressure can produce a headache but mild or moderately high blood pressure is not a common cause of a headache.
Headache accompanies many general illnesses like the common cold and other fevers. But some illnesses are specifically associated with headache including lupus erythromatosis, infectious mononucleosis, inflammation of the thyroid, chronic lung disease, HIV infection (AIDS), a special form of inflammation of the arteries known as temporal-arteritis and very high blood pressure.
Here the concern is not necessarily on account of the seriousness of the underlying disease but the stress it is causing to the patient. Such a patient needs careful evaluation from both the point of view of investigation of the underlying cause and reassurance of the patient. Real emergency cases include brain haemorrhage of various kinds and extremely high and complicated blood pressure, referred to as malignant hypertension by the doctors, meningitis — inflammation of the surrounding layers of the brain, slow or rapidly growing tumours of the brain, glaucoma of the eyes accompanied with visual deterioration and hallows seen around the lights. Neuralgias, meaning electric irritation of the nerves, usually affects the 5th-11th cranial nerves or occipital nerves. This group of headaches can be extremely distressing and cause an emergency.
With the advent of CT scan, MRI and
other diagnostic techniques, diagnosis of the underlying disease can
be made quickly and with reasonable accuracy. Here, however, lies the
catch. Each headache does not require a CT scan or MRI and it requires
the judgement of the treating physicians/surgeons to decide as to when
there is a need to use this option.