Continuum, December 2006, Volume 12, Issue 6

Designing a comprehensive and practical classification schema for headache disorders has been an elusive goal for many reasons. The International Classification of Headache Disorders, 2nd Edition (ICHD-II) is the best attempt to date, but it, like its predecessor the ICHD-I, is plagued with a number of limitations. It was designed as both a research and clinical tool but can be frustrating for practitioners in either area. Primary headaches, such as migraine, chronic daily headache, and "other" headaches, such as new daily persistent headache, are particularly problematic sections of the classification. In addition, classification of a number of more complex (ie, where pathophysiology is poorly understood) secondary headaches, such as medication overuse and posttraumatic headaches, is also vexing. This chapter is an attempt to summarize the ICHD-II, focusing on primary headache types, and suggest best practices for usage of it.(C) 2006 American Academy of Neurology

The migraine attack can be divided into four phases. Premonitory phenomena occur hours to days before headache onset and consist of psychological, neurological, or general symptoms. The migraine aura is comprised of focal neurological phenomena that precede or accompany an attack. Visual and sensory auras are the most common. The migraine headache is typically unilateral, throbbing, and aggravated by routine physical activity. Cutaneous allodynia develops during untreated migraine in 60% to 75% of cases. Migraine attacks can be accompanied by other associated symptoms, including nausea and vomiting, gastroparesis, diarrhea, photophobia, phonophobia, osmophobia, lightheadedness and vertigo, and constitutional, mood, and mental changes. Differential diagnoses include cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoenphalopathy (CADASIL), pseudomigraine with lymphocytic pleocytosis, ophthalmoplegic migraine, Tolosa-Hunt syndrome, mitochondrial disorders, encephalitis, ornithine transcarbamylase deficiency, and benign idiopathic thunderclap headache.(C) 2006 American Academy of Neurology

The treatment of migraine may be acute (abortive) or preventive (prophylactic). Preventive therapy is used in an attempt to reduce the frequency, duration, or severity of attacks. Additional benefits include enhancing the response to acute treatments, improving a patient's ability to function, and reducing disability. The major medication groups for preventive migraine treatments include anticonvulsants, antidepressants, [latin sharp s]-adrenergic blockers, calcium channel antagonists, serotonin antagonists, botulinum neurotoxins, nonsteroidal anti-inflammatory drugs, and others (including riboflavin, magnesium, and petasides). If preventive medication is indicated, the agent should be chosen from one of the first-line categories, based on the drug's relative efficacy in double-blind, placebo-controlled trials, its side effect profile, and the patient's preference, as well as coexistent and comorbid conditions.(C) 2006 American Academy of Neurology

Medication overuse headache is considered to be the result of an interaction between an exposure (overuse of analgesics) and a biologically vulnerable individual (migraineur). Several lines of evidence suggest that in migraineurs, but not individuals without migraine, medication overuse is a risk factor for chronic daily headaches. Therefore, medication overuse headache should be prevented. In individuals with already established daily headaches and medication overuse, treatment requires a comprehensive plan that includes education, establishment of realistic goal, detoxification, and aggressive nonpharmacological and pharmacological preventive strategies.(C) 2006 American Academy of Neurology

The relationship between the cerebrovascular system and headache is multifaceted and incompletely understood. However, several important observations have been made. Head pain can be generated by stimulation of the intracranial vasculature. This is evident on an experimental level as well as with common vascular conditions. Headaches occur in association with ischemic strokes, cervical artery dissections, intracranial aneurysms, and following cervical or cranial vascular procedures. In addition, migraine has been identified as a risk factor for the development of vascular diseases such as ischemic stroke and cervical artery dissection. Patent foramen ovale, a structural cardiovascular disorder, is more common in patients with migraine with aura. In addition, certain rare migraine syndromes (aura without headache, hemiplegic migraine, retinal migraine, ophthalmoplegic migraine, and basilar-type migraine) may mimic stroke. Study of each of these entities will lead to a better understanding of the pathophysiology of headache and its relationship to the vascular system.(C) 2006 American Academy of Neurology

There are multiple reasons to justify the inclusion of behavioral medicine in headache management. Research identifies stress as a prevalent headache trigger or aggravator. The use of direct questions, headache diaries, and behavioral analysis can help identify relevant stressors. Stress management therapies consistently yield from 35% to 55% headache improvement over baseline and, when combined with appropriate medication, provide a synergistic effect. Smoking cessation and aerobic exercise can help. Use of compliance-enhancement techniques can improve adherence to both medical and behavioral treatment recommendations and may improve clinical outcomes. Behavioral factors play an important role in complex cases of medication-overuse headache. The addition of behavioral therapy (eg, biofeedback and nonpharmacological coping skills) can help reduce the high rates of relapse after drug withdrawal. Attention to psychiatric comorbidity, using focused empathic interview techniques, brief psychometric screens (eg, Beck Depression Inventory II), and patient checklists (Primary Care Evaluation of Mental Disorders [PRIME-MD]) can help the physician employ treatments that address both headache and relevant psychiatric conditions, increase patient satisfaction, and improve outcomes. Personality disorders are often comorbid with severe chronic daily headache conditions and complicate treatment. Appropriate therapeutic responses to behavioral red flags (the "hug" sign, entitlement expectations, pseudocoping, covert narcotic requests, "sincere" but disingenuous behavior, inappropriate underlying anger, problematic family issues) can keep headache treatment on a productive path. Simple communication guidelines can help reduce dysfunctional pain-related family behavior. Behavioral medicine referrals for biofeedback and stress management therapy can be useful in straightforward cases and should be a requirement for challenging patients and severe forms of chronic daily headache.(C) 2006 American Academy of Neurology