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Headache is a nearly universal symptom. As an example of the
prevalence of headache, a study of 410 patients who had visited
a primary care internal medicine practice found that headache was the
fourth most common symptom and was exceeded only by fatigue, back
pain, and dyspnea.1 In an early study of over 1
million unselected individuals from the general population, headache
was the single most common current symptom and was reported by 39% of
men and 56% of women.2 As physicians,
nearly all of us have had personal experience with headache and
can understand the headache descriptions that we hear from our patients.
Chapter 17 elegantly details the prevalence of this common symptom
and of common primary headache syndromes. Primary headaches are
those without a pathologic basis.3–5 These
are benign recurring headaches of unknown cause. The most common
primary headache syndromes are migraine, tension-type, and cluster
headache. Secondary headaches are the result of an underlying pathologic
cause.
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When faced with the large numbers of patients who seek medical
evaluation for headache, clinicians seek to identify the rare patient
with a serious headache from the rest whose headache is benign in
nature. Two general approaches assist this effort. Firstly, one
must learn the warning symptoms and signs that suggest a pathologic
cause for headache. Many published reviews have offered such advice.4,6,7 A
complementary approach is to learn to confidently diagnose benign
primary headache syndromes through careful history taking and the
systematic application of established diagnostic criteria. Primary
headaches are clinical diagnoses that are based on history taking
alone. With the exception of the occasional persistence of a partial
Horner’s syndrome among asymptomatic patients with a history
of cluster headaches, the physical examination of a patient with
primary headaches is normal during headache-free intervals.
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The most commonly used criteria are the International Headache
Society (IHS) classification and diagnostic criteria for headache
disorders, cranial neuralgias, and facial pain.8 The
use of these criteria helps to identify uniform populations of patients
for research and epidemiologic studies. The criteria themselves,
however, are complicated, not easily committed to memory, and may
be unnecessarily restrictive in the daily clinical care of patients.
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When evaluating individual patients with headache, clinicians
will benefit from understanding which historical features are most
useful in establishing or excluding a particular primary headache
diagnosis. In this chapter, I review and summarize published clinical
series of patients with migraine, tension-type headache, and cluster
headache to determine the sensitivity, specificity, and likelihood
ratios of individual historical features.
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Clinicians may initially classify all headaches as either old
or new. Old headaches are similar to those that have occurred repeatedly
over time. Primary headaches are old headaches. New headaches are
either headaches of recent onset or those that represent a change
in the character or pattern of an old headache. A new headache may
ultimately prove to be the first instance ...