Chronic Daily Headache: Same Old, Same Old
"Chronic daily headache" (CDH) refers to the unhappy situation
in which headaches are present at least fifteen days per month.
Headaches can even occur every day or almost every day. CDH is
more of a category than a final diagnosis, and different,
recognizable patterns of headache are included in this category.
It is important to distinguish among the different patterns
because, once recognized, they can indicate the underlying cause
and dictate appropriate treatment.
CDH can occur in the form of either "primary headaches" or
"secondary headaches." Secondary headache means that the
headache is a symptom of some other disease or process. In this
case, the best treatment is the one that addresses the
underlying cause. Primary headache means that the headache
disorder itself is the disease and is not a symptom of something
else.
The most common primary headache condition is "tension-type
headaches." Generally affecting the left and right sides
equally, tension-type headaches often involve the back of the
head and neck, but can also include the front of the head. These
headaches are usually mild to moderate in intensity and have
pressing or tightening qualities. Nausea, photosensitivity and
sound sensitivity are not prominent in this headache disorder
and tension-type headaches do not usually worsen with exertion.
Migraine is another common primary headache disorder which, when
present more days than not, is also categorized as CDH. Migraine
attacks typically last 4-72 hours when untreated. They are of
moderate to severe intensity and often have a pulsating quality.
They show increased tendency to affect just one side of the head
and to include the associated symptoms of nausea, light
sensitivity and sound sensitivity. They usually worsen with
exertion.
While some people have frequent, individual, migraine attacks
that span more than 15 days per month and are therefore
categorized as CDH, another form of migraine involves a blending
together of attacks into a more continuous, never-ending
pattern. This usually occurs in people who previously had the
more recognizable pattern of distinct, individual, migraine
attacks. Just what happens in these cases--or even what to call
it when it does happen--is a source of great debate among
headache experts. One camp of experts calls it "chronic
migraine" and another camp calls it "transformed migraine."
To make matters even more interesting, a person can have more
than one type of headache, for example, a mixture of migraine
and tension-type headaches. When this occurs, the mixture can be
difficult to distinguish from the previously mentioned chronic
(or transformed) migraine.
Two other kinds of primary headache are rarer than migraine and
tension-type headaches, and show quite different
characteristics. These are "hemicrania continua" and "chronic
cluster." Hemicrania continua ("hemicrania" means half-headed
and "continua" means continuous) is a strictly one-sided
headache which can wax and wane in intensity without resolving.
It does not include migraine's usual associated symptoms of
nausea, light sensitivity, sound sensitivity and exertional
aggravation. Chronic cluster, like its less-frequent "episodic"
form, involves intense, recurring pain in or around just one eye
that lasts for only 15-180 minutes per attack, but which can
occur more than once per day. Unlike its episodic cousin,
chronic cluster does not go into remission without treatment.
Secondary headaches taking the form of CDH can be due to
numerous causes. Among them are head injury, arthritis of the
neck bones, arthritis of the jaw joints (TMJs), sinus disease,
breathing problems during sleep, tumors or other conditions
causing increased pressure within the braincase, and leakages of
the cerebrospinal fluid that surrounds the brain and spinal cord.
Two secondary forms of CDH deserve special mention--giant cell
arteritis and medication overuse headaches. Giant cell arteritis
(previously called temporal arteritis) occurs in people who are
at least 50 years old and becomes more common in subsequent
decades of life. It involves inflammation of larger-diameter
arteries supplying blood to the brain and the rest of the head
and, untreated, can lead to stroke or blindness. So it is
important to recognize and treat this source of headaches before
these complications occur. Classically, people with giant cell
arteritis show a swollen, stiff, tender artery just beneath the
skin of one or both temples. When this occurs, it facilitates
diagnosis, but giant cell arteritis can still be present in the
absence of this tell-tale sign. As a rule of thumb, giant cell
arteritis should be considered as a possible diagnosis in every
new headache disorder starting at the age of 50 or older.
Medication overuse headaches (also known as rebound headaches)
occur when a primary headache disorder becomes transformed into
an even worse secondary headache disorder via too many doses of
as-needed medication. Typically, the primary headache disorders
involved are either migraine or tension-type headaches, and the
transformation occurs when the headache-sufferer takes
need-driven medication for them at least two to three days each
week. When the as-needed medication is a painkiller this
syndrome is called "analgesic rebound" and when a triptan drug
is used, it is called "triptan rebound." Triptans are newer
drugs, which include sumatriptan (Imitrex) and rizatriptan
(Maxalt), that interact with specific chemical receptors and
halt the generation of migraine attacks. The bottom line with
medication overuse headaches is that they don't get better until
the drug that caused them is withdrawn and, even then, can take
up to two months to wash out.
The group of disorders known as chronic daily headache afflicts
3-5% of the worldwide population and is a source of major
disability in the form of lost or decreased functioning at home
and at work. While many people with CDH treat them on their own,
medical management can reduce suffering and improve quality of
life.
(C) 2005 by Gary Cordingley