What Tests Are Used to Diagnose Headache?
Diagnosing a headache is like playing Twenty Questions.
Experts agree that a detailed question-and-answer session with
a patient can often produce enough information for a diagnosis.
Many types of headaches have clear-cut symptoms which fall into
an easily recognizable pattern.
Patients may be asked: How often do you have headaches?
Where is the pain? How long do the headaches last? When did you
first develop headaches? The patient's sleep habits and family
and work situations may also be probed.
Most physicians will also obtain a full medical
history from the patient, inquiring about past head trauma or
surgery, eye strain, sinus problems, dental problems, difficulties
with opening and closing of the jaw, and the use of medications.
This may be enough to suggest strongly that the patient has migraine
or cluster headaches. A complete and careful physical and neurological
examination will exclude many possibilities and the suspicion
of aneurysm, meningitis, or certain brain tumors. A blood test
may be ordered to screen for thyroid disease, anemia, or infections
which might cause a headache.
A test called an electroencephalogram (EEG) may
be given to measure brain activity. EEG's can indicate a malfunction
in the brain, but they cannot usually pinpoint a problem that
might be causing a headache. A physician may suggest that a patient
with unusual headaches undergo a computed tomographic (CT) scan
and/or a magnetic resonance imaging (MRI) scan. The scans enable
the physician to distinguish, for example, between a bleeding
blood vessel in the brain and a brain tumor, and are important
diagnostic tools in cases of headache associated with brain lesions
or other serious disease. CT scans produce X-ray images of the
brain that show structures or variations in the density of different
types of tissue. MRI scans use magnetic fields and radio waves
to produce an image that provides information about the structure
and biochemistry of the brain.
If an aneurysm-an abnormal ballooning of a blood
vessel-is suspected, a physician may order a CT scan to examine
for blood and then an angiogram. In this test, a special fluid
which can be seen on an X-ray is injected into the patient and
carried in the bloodstream to the brain to reveal any abnormalities
in the blood vessels there.
A physician analyzes the results of all these
diagnostic tests along with a patient's medical history and examination
in order to arrive at a diagnosis.
Headaches are diagnosed as
Vascular
Muscle contraction (tension)
Traction
Inflammatory
Vascular headaches—a group that includes the well-known
migraine—are so named because they are thought to involve
abnormal function of the brain's blood vessels or vascular system.
Muscle contraction headaches appear to involve the tightening
or tensing of facial and neck muscles. Traction and inflammatory
headaches are symptoms of other disorders, ranging from stroke
to sinus infection. Some people have more than one type of headache.
