Upon completion of the chapter, the reader will be able to:
Differentiate types of headache syndromes based on clinical features.
Recommend nonpharmacologic measures for headache treatment and prevention.
Determine when the pharmacologic treatment of headache is indicated.
Construct individualized treatment regimens for the acute and chronic management of headache syndromes.
Monitor headache treatment to ensure its safety, tolerability, and efficacy.
Headache is a common medical complaint with approximately 47% of the adult population experiencing at least one headache per year.1 KEY CONCEPT Even when persistent or recurrent, headaches are usually a benign primary condition; secondary headaches are caused by an underlying medical disorder and may be medical emergencies. Primary headache syndromes are the focus of this chapter. Patients may seek headache care from multiple providers. All clinicians should be familiar with the various types of headache, clinical indicators suggesting the need for urgent medical attention or specialist referral, and nonpharmacologic and pharmacologic options for treatment. KEY CONCEPT The International Headache Society (IHS) classifies primary headaches as migraine, tension-type, or cluster and other trigeminal autonomic cephalalgias.2
EPIDEMIOLOGY OF HEADACHE DISORDERS
Migraine is a primary headache disorder with an estimated 3-month prevalence rate in the United States of 16.6% to 22.7%, based on data from multiple general health surveillance studies.3 Prevalence of migraine depends on age, gender, and income. In children and adolescents onset typically begins at age 7.9 years for males and 10.9 years for females.4 In adults, prevalence is much higher in women (17.1%) than men (6.1%), and occur most often between 30 and 49 years of age.5 The difference in gender distribution is thought to be due to hormonal differences. In households with an annual income greater than $90,000, migraine prevalence is much lower (13.6% women; 4.2% men) than in households with an annual income less than $22,500 (20.1% women; 8.8% men).5
KEY CONCEPT Tension-Type Headache (TTH) is the most common primary headache disorder and can be further divided into episodic or chronic.2 TTHs are underrepresented in clinical practice because most patients do not present for care.6 The term TTH is used to describe all headache syndromes in which sensitization to pericranial nociception, noxious stimuli, is the most significant factor in the pathogenesis of pain.7 Overall prevalence of TTH is approximately 86%, and incidence is more common in women than men. Episodic TTH is the most common type followed by frequent episodic TTH, and finally chronic TTH. Incidence of TTH increases until approximately age 40, then incidence begins to slowly decline.6 Environmental factors, as opposed to genetic predisposition, play a central role in the development of TTH. The mean frequency of attacks is 3 days per month in episodic disorders; chronic TTH is defined as 15 or ...