Constance J. Johnson
Epidemiology
Headache is a common complaint with most adults reporting a history of recurrent headache. In surveys of visits to physicians, headache was named by patients as the principal reason for approximately 2% to 4% of all visits to internists, general practitioners, and family practitioners (1). Most patients have a primary headache disorder that meets the criteria for tension-type headache, migraine, or cluster headache. In primary care, a patient with a stable pattern of moderate to severe episodic headache with a normal examination is most likely to have migraine. The Landmark Study of 1,203 patients consulting for headache in the office revealed that 94% of patients had migraine or probable migraine and 25% did not receive a diagnosis of migraine (2). Most headache sufferers depend on self-care with over-the-counter (OTC) remedies rather than on visits to their doctors to deal with their headache problems. Fewer than half of active migraine sufferers consult a physician for headache each year (3).
Less commonly, patients have a secondary headache disorder such as giant cell arteritis, acute sinusitis, or intracranial infection, tumor, and hemorrhage. These patients often have focal neurologic signs or symptoms, systemic disease, and/or abnormal examinations.
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Classification
This chapter uses the International Classification of Headache Disorders II (4). These criteria, originally published in 1988, and revised in 2004, are widely used for clinical and research purposes. Headaches are classified as primary, defined by symptoms, or as secondary, defined by etiology. Most patients presenting to the office have one of the two common primary headache disorders, migraine or tension-type headache. Debate within the headache community continues about the practical difference between tension-type and migraine headache as individual patients often have both headache types and some patients with tension-type headache respond to drugs used for migraine, and some with migraine respond to regimens recommended for tension-type headache. Secondary headache disorders are due to drugs or toxins, infection such as meningitis, traction on pain-sensitive intracranial structures from tumor, hemorrhage or edema, inflammatory disease such as vasculitis, or diseases of the eye, ear, sinuses, and teeth.
General Approach to the Patient with Headache
History
The history provides the most useful information for evaluating headache, particularly a careful account by the patient of the current or most recent episode. Many patients have several different types of headache so it is useful to begin with the one that is most important to the patient. The most informative aspects of the history in determining etiology are the temporal profile, associated symptoms, disability, and family history; the least informative aspects are the character and location of the pain. Undue emphasis should not be placed on differentiating the character of the pain, because the subjective interpretation of headache pain is so variable. The following questions are helpful in the differential diagnosis of headache. The interpretation of patients’ answers to these questions is discussed in detail in later sections on specific headache syndromes.
Associated Factors
Is there a warning of the attack such as malaise, food cravings, yawning, focal paresthesias, weakness, or visual symptoms? Are there triggers such as withdrawal from caffeine, alcohol ingestion, vasodilator use, psychosocial stress, perimenstrual period, foods, drug use, position, sexual orgasm, exertion, or tobacco? What medication is the patient taking for other conditions? To what does the patient attribute the headache? Does the patient fear a dreaded cause such as a tumor?
Temporal Features
When did the patient first experience this type of headache? Does the headache begin suddenly, or build up slowly over a period of several hours or days? How long does the pain last: seconds, minutes, hours, or days? What time of day does the headache occur? Does it awaken the patient from sleep? Does it recede after the patient has been up for several hours? What is the frequency of headaches? How long do the headaches last (maximum, minimum, average)? Is the headache episodic or continuous? Did the patient have headaches in the past? What kind?
Character and Location of Pain
What does the pain feel like: band-like, squeezing, pressure, pounding or throbbing? Where is the pain: one side or all over the head, in the eyes or radiating up the back of the neck? On a scale of 1 to 10, how severe is the mildest, the worst, and the average headache? How does the patient rate this headache pain compared with the pain of other headaches or other situations (e.g., worst headache ever, worst pain in my life)?
Aggravating and Alleviating Factors
Does anything make the headache pain worse: bending, standing, sneezing, straining or coughing? What factors reduce the headache: lying down, ice packs, pressing on the temples, avoidance of activities or medications? How is the patient currently treating the headache?
Environmental Exposures
Is there a history of carbon monoxide exposure such as working in a garage or use of unvented or inadequately vented heating systems? Did the headache start after exposure to fumes or dust containing lead? Table 8.2 in Chapter 8 lists these and other environmental exposures that can cause headache.
Associated Symptoms
Does the patient have nausea and vomiting or sensitivity to light, sound, and odors? Are there neurologic symptoms such as visual obscurations, diplopia, paresthesias, weakness, vertigo, or loss of consciousness? Did the patient have motion sickness or cyclic vomiting as a child? Does the patient note scalp tenderness or hypersensitivity to touch during headaches?
Prior Evaluation
Has the patient been evaluated for headache, and what were the results? It is important to request previous
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records for patients who give a history of new onset headache. Sometimes requesting the records reminds the patient of a previous headache evaluation and sometimes the previous records reveal such a history despite poor recall by the patient. In either case, this information can be particularly valuable in evaluating a patient who describes recent onset of headaches.
Disability or Functional Impact
How are the headaches affecting work, school, social activities, and interpersonal relationships? How many days per month does the patient miss work/school or social/family events because of headache? How often does the patient have reduced productivity because of headache? How many days per month does the patient have headache?
Family and Household History
Is there a history of headaches in the family, or other people living in the patient's household? What type?
Physical and Laboratory Examination
In most cases, the history suggests the probable basis for a patient's headache. Appropriate physical examination and laboratory studies are described for each type of headache in later sections. The appropriate extent of the examination may vary from a limited physical examination (e.g., in a patient with headache after vasodilator therapy) to an examination focused on structures that may be the source of the headache. A complete neurologic examination together with imaging studies or laboratory tests may be needed for patients with new-onset headache, marked change in prior headache pattern, or neurologic abnormality such as weakness, suggesting a secondary headache disorder.
The role of imaging studies for the patient with nonacute headache and a normal neurologic examination is addressed by an American Academy of Neurology (AAN) practice guideline (5). Based on a review of all relevant publications, there was sufficient information to recommend against the routine use of imaging in such patients with migraine, including migraine with aura. Because of the meager amount of published evidence, the guidelines made no recommendations for patients other than those with migraine. The guidelines cite one study of a large health maintenance organization population in which it was estimated that a tumor would be found in fewer than one in 10,000 patients who have headache as their only symptom and who have a normal neurologic examination. Table 87.1 summarizes the imaging findings in migraine and unspecified headache. For patients with nonacute headache and an unexplained abnormal finding on neurologic examination, the AAN guidelines concluded that there is fair evidence to justify obtaining neuroimaging; it also concluded that the data are insufficient regarding the relative sensitivity of magnetic resonance imaging (MRI) or computed tomography (CT) scanning in the evaluation of headache (5). Chapter 86 describes the properties of these two imaging techniques.
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TABLE 87.1 Abnormal Computed Tomography or Magnetic Resonance Imaging Findings in Migraine and Unspecified Headache |
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Principles of Initial Treatment
Patients with a history consistent with tension-type headache or migraine and a normal examination can begin treatment. A more extensive investigation should be carried out for patients who show either of the following situations after initial treatment: failure to respond to treatment of the presumed condition or significant changes in complaints or physical findings that point to one of the less common causes of headache discussed later. The following are “red flags” suggesting that the headache is secondary: onset after 50 years of age, thunderclap onset, systemic illness, underlying malignancy or acquired immunodeficiency syndrome (AIDS), and, a new-onset, steadily progressive headache.
Treatment Expectations
In studies on the issue of expectations of physicians and patients, the majority of physicians expected that their patients would demand pain relief and not care as much about getting an explanation for their problem. Patient surveys, however, have shown that a minority of patients feel that pain relief was most important; many more patients rate receiving an explanation of their problem as their most important concern. Population studies of migraine sufferers have shown that they are both underdiagnosed and undertreated. The American Migraine Study, a
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comprehensive population survey, reported that only 29% of migraine sufferers were “very satisfied” with their treatment. Patients were dissatisfied with both time to onset and degree of pain relief from their medication, and the majority were not using migraine-specific prescription medications (3).
When total relief of headache pain is not possible, the patient must be helped to understand the limitations of drug therapy. For primary headache disorders, pain relief is not usually fully attained for all attacks and some patients require preventative medication. Part of the patient education process for migraine is to convince the patient that he/she has a disease that requires management over a lifetime. The patient is almost always expecting a cure when there is none. A common concern of migraine patients is “to get to the bottom of this.” The patient needs education as to the mechanisms of migraine and treatment measures analogous to educating a diabetic or hypertensive patient.
Specific Headache Syndromes
Tension-Type Headache and Chronic Daily Headache
Classification and Diagnostic Criteria
Tension-type headache is the most common type of primary headache. Previous terms include muscle-contraction, stress, idiopathic, and psychogenic headache. There are three types, two episodic and one chronic: infrequent episodic tension-type headache (ETTH) with headaches <1 day a month, frequent ETTH with headaches 1 to 14 days a month, and chronic tension-type headache with headache ≥15 days a month. Additional criteria for ETTH (4) include the following:
Criteria for chronic tension-type headache (4) include the following:
Patients who fulfill all but one of the criteria for ETTH and do not meet criteria for migraine without aura are classified as probable ETTH. Patients with infrequent TTH rarely seek medical attention and do not require prescription medications. Patients with frequent ETTH or chronic tension-type headache frequently seek medical care, and often require prescription medications including preventative medications. Chronic tension-type headache usually evolves from ETTH and results in significant disability and distress.
The term chronic daily headache (CDH) is not in the international classification but is in widespread use referring to a group of conditions affecting 4% to 5% of the population who suffer with headache 15 or more days a month (6). This group includes chronic tension-type headache, chronic migraine (CM) (see Migraine Classification), and medication-overuse headache. Medication-overuse headache, frequently called “rebound headache,” has five subgroups: ergotamine, triptan, analgesic, opioid, and combination medication-overuse headache. Analgesic overuse headache is probably the most common type in primary care.
Criteria for analgesic-overuse headache (4):
The patient typically has an escalating headache pattern for which increasing dosages of analgesics were taken, resulting in conversion to a daily headache pattern. Patients often do not consider OTC drugs as medications. A careful history of all OTC and prescriptions medications used for any condition should be elicited. Medication overuse can result in refractoriness to preventative medication. Treatment consists of withdrawal from the analgesic.
Physical examination of the patient with ETTH and CDH is normal. Some patients have neck or scalp muscle tenderness, which is nonspecific.
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TABLE 87.2 Characteristics of Migraine and Tension Type Headaches |
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Pathogenesis
Headache is a neurologic disorder. For many years tension-type headache was presumed to be a somatic consequence of psychosocial stress or muscular tension in the head and neck. Neither increased muscle tension nor precipitating stress is specific for tension-type headaches; both are also common in migraine, which is the prototype of a neurologic headache disorder. Table 87.2 summarizes the data on the frequency of several characteristics in a large number of patients and shows considerable overlap between tension-type and migraine headaches. The pathogenesis may be similar (see Migraine, Pathogenesis). In patients with CDH secondary to medications, there is likely an interaction between medication effect and susceptibility to headache as analgesics do not induce chronic headache in the majority of people who take daily analgesics. Medication-overuse headache can occur with simple analgesics, opioids, barbiturates, ergotamines, or triptans (7). Depression and anxiety have been described as common comorbidities in tension-type headache, but the literature is contradictory, and the relationship seems more likely with chronic tension-type headache than ETTH (8).
Treatment
Patients with intermittent headache that is not severe usually respond to simple OTC analgesics. Most of these patients do not seek medical attention but report headaches on review of systems. Patients with frequent ETTH or CDH often seek medical attention. The use of acute headache medications including analgesics, opioids, ergotamines, barbiturates, and triptans more than 2 to 3 days a week should be avoided. Patients who are taking these medications daily or near daily should withdraw from these medications for at least 2 months in order to establish whether the headache is medication induced (consensus recommendation, the International Classification of Headache Disorders II) (4). If caffeine overuse and withdrawal seem to correlate with the complaint of chronic daily headache, patients should be counseled to restrict or eliminate caffeine intake.
Nonpharmacologic Treatment
It is usually helpful to explain to the patient that the mechanism of pain is related to dysfunction of the brain. Emphasis on the benign nature of the headache is important to relieve concerns regarding more serious pathology such as a brain tumor. For patients seeking nonpharmacologic relief of symptoms, massage of the scalp and neck muscles or use of relaxation techniques (see Chapter 22) can be recommended. Additionally, any other approach that the patient may have found helpful can be encouraged, including complementary and alternative treatment modalities (see Chapter 5).
Pharmacologic Treatment
Symptomatic treatment with medications is often necessary for moderate severity ETTH. Most patients have used headache remedies containing acetaminophen, aspirin, or other nonsteroidal anti-inflammatory drugs (NSAIDs) before consulting their physician about treatment. For mild-to-moderate headaches, an additional trial of these mild analgesics should be recommended if they have not been taken at effective dosages.
A number of drugs are widely prescribed for patients with ETTH that is unresponsive to acetaminophen, aspirin, or other NSAIDs. These drugs include codeine sulfate, propoxyphene, and products that combine analgesics, sedatives, and caffeine (e.g., butalbital/caffeine plus aspirin or acetaminophen) or that includes hydrocodone or oxycodone plus aspirin or acetaminophen. Each of these drugs can lead to dependency. Therefore, it is unwise to initiate treatment with them unless there is a strict contractual agreement regarding the conditions for their use (see Chapter 29). Any acute medication should be limited to 3 days a week in order to avoid transformation to CDH.
When disabling ETTH occurs in migraineurs, a triptan will abort the headache in a large proportion of patients (see Migraine, Acute Treatment). If a patient with ETTH reports attacks that require bedrest, the diagnosis of migraine should be considered and treatment appropriately altered.
Preventative therapy is warranted for the patient whose tension-type headaches are frequent and not relieved by a trial of acute medication withdrawal. Tricyclic antidepressants have been used extensively as first-line
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preventative treatment in tension-type headache. A meta-analysis of placebo-controlled clinical trials concluded that tricyclic antidepressants greatly diminish headache suffering and analgesic use in at least one third of patients (9). One trial showed that when tricyclic antidepressants were used in conjunction with stress management techniques (relaxation and cognitive coping; see Chapters 20 and22), the effectiveness of the two interventions was additive, producing greater than 50% reduction in headache index scores in 64% of patients, compared with 38% of those given tricyclic antidepressants only, 35% of those given stress management only, and 29% of those given placebo. The doses of tricyclic antidepressants approached the levels used in the treatment of depression (amitriptyline 100 mg and nortriptyline 75 mg/day) (10). Chapter 24 discusses the use of tricyclic antidepressants. When tricyclic antidepressants fail, other classes of preventative medications such as β-blockers and antiepileptics as used in migraine can be tried.
Migraine
Classification and Diagnostic Criteria
The classification of migraine headache was revised in 1988 from the designations “common” and “classic” migraine to migraine without auraand migraine with aura. The criteria were further revised in 2004 (4).
Consensus criteria for the syndrome of migraine without aura include the following:
Migraine is an episodic headache disorder and between attacks the patient is well. Some patients have a prodrome with malaise, yawning, or food craving. The headache in a migraine attack usually increases gradually, reaching a peak after several hours and lasting for several hours to 1 day in typical cases. Attacks lasting 2 to 3 days are not uncommon and some migraine attacks last 1 to 2 weeks. The pain may be described as pounding or throbbing, but the quality of the pain is variable and may be aching, pressing, stabbing, or vise-like. Although headaches are typically unilateral at the beginning of a single attack, they may be bilateral at onset or spread to the entire head during an attack. Most patients have attacks on both sides of the head; in a minority of patients, headaches are always on the same side (side-locked migraine). When all but one criterion is met, the diagnosis of probable migraine is used. When attacks are frequent, i.e., ≥15 headache days a month, the condition is referred to as chronic migraine (CM) (4).
The criteria for the syndrome of migraine with aura (4) are the following:
The patient has had at least two attacks fulfilling the following criteria.
Migraine with aura is characterized by attacks beginning with reversible neurologic symptoms, usually visual or sensory, developing over 5 to 20 minutes and lasting less than 60 minutes, after which headache pain begins. Fortification spectrum are almost specific for migraine; these are slowly enlarging scotomata surrounded by luminous angles that slowly change shape and appear to move across the visual fields (Fig. 87.1). In a population-based study, aura occurred with each attack in 18% of patients (migraine with aura), no aura occurred in 64% (migraine without aura), and 13% had both types of migraine. The remaining 5% had aura without headache (11). Although a third of migraine patients will have an aura with some attacks, most patients do not. Relying on aura to make the diagnosis of migraine will result in frequent misdiagnosis.
Further migraine syndromes include familial and sporadic hemiplegic migraine, basilar-type migraine, childhood periodic syndromes, and complications of migraine (migrainous infarction) and status migrainous (4). Patients presenting with auras other than visual field
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abnormalities or sensory symptoms (e.g., aphasia, hemiplegia, alterations of consciousness, diplopia) should be referred for neurologic evaluation and management.
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FIGURE 87.1. Lashley's maps of the progression of his own fortification spectra at varying time intervals after the onset of a migrainous attack. The X in each instance indicates the visual fixation point. The numbers represent minutes. (From Raskin NH, Appenzeller O. Headache. Philadelphia, WB Saunders, 1980 ; as appeared in Lashley KS. Arch Neurol Psychiatry 1941;46:331 .) |
Migraine is more common than is generally appreciated, and many patients with recurrent moderate to severe migraine headaches are misdiagnosed as having tension-type or sinus headaches, often because they have nonthrobbing bilateral headache located over the sinus regions. Failure of analgesics in a patient with recurrent, disabling headaches requires a reevaluation of the diagnosis.
In the differential diagnosis of migraine, the most common secondary headache disorders are transient ischemic attacks (TIAs) or other cerebrovascular events, particularly in middle-age and older patients (see Chapter 91). Migrainous infarction occurs during a typical migraine with aura attack and is associated with an ischemic infarction on neuroimaging. Symptoms of migraine aura typically last for 5 to 60 minutes; TIA symptoms last minutes to 24 hours. Older patients with suspected migrainous ischemic events, particularly those with migraine equivalents (aura symptoms without headache), should be evaluated for TIA (see Chapter 91) before their symptoms are attributed to migraine.
Pathogenesis
Migraine is a primary disorder of the brain in which neural events mediated by the trigeminal system result in activation of nociceptors of pain-producing structures (12). Neuropeptides are released, and plasma protein extravasation occurs. These mediators, of which calcitonin gene-related peptide (CGRP) is a major messenger, result in vasodilatation of large extracranial arteries, venous sinuses, and dural arteries, which is believed to account for the painful throbbing of migraine headache (13). Positron emission tomographic (PET) studies during migraine reveal activation of brainstem areas (14). The pain of migraine felt over the frontal and temporal regions is believed to be mediated by the ophthalmic division of the trigeminal nerve; and, posterior pain in the parietal, occipital, and cervical regions is believed to be mediated by activation of neurons in the dorsal horns of C1 and C2 (13).
Epidemiology and Natural History
The American Migraine Study, a large population-based study of migraine in the United States, found the prevalence of migraine to be 18% in adult women and 6% in adult men. This approximates 28 million migraine sufferers, and of these, more than 4 million have one or more attacks per month. More than half of working people with migraine report that they miss more than 2 days of work per month (15).
Migraine headache sufferers frequently have a positive family history for headache in a first-degree relative (16). Asking about headache rather than migraine in the family is more productive, as many patients will report no migraine relatives, but will report many headache relatives. Many patients report motion sickness and vertigo as a child, with vertigo persisting into adulthood.
The onset of migraine most commonly occurs between the ages of 15 and 25 years but can occur at any time throughout the life span, including childhood. Episodic attacks are characteristic of migraine headache. The frequency of migraine attacks varies widely from rare episodes to several per week. Migraines tend to become less frequent and less severe with age, particularly after menopause in women. Depression and anxiety are common comorbidities of migraine headache and should be treated (17).
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Possible Precipitating Factors
Trigger factors increase the likelihood of a migraine attack and include psychosocial stress, intake of alcoholic beverages, weather changes, and hormonal events in women. For women, the perimenstrual period may result in increase in migraine frequency and severity. Oral contraceptives and pregnancy may worsen or improve migraine (18). A wide variety of substances may initiate headaches in susceptible subjects: vasodilators (nitrates); alcohol; chocolate; aged cheeses, and other foods containing tyramine; food additives including monosodium glutamate and aspartate. Withdrawal of caffeine or ergotamine can cause headaches. An unusually long period of sleep (e.g., sleeping in on weekends) may provoke migraine. Attacks may occur during periods of relaxation, such as weekends, holidays, or vacations.
Nonpharmacologic Treatment
Patients should be educated about migraine as a disease and the avoidance of known trigger factors. There are no consistently implicated trigger factors; however, each patient should be encouraged to try eliminating potential triggers.
During an established attack, a patient usually feels better reclining in a dark room with a cool compress or ice pack applied to the head. This is the only practice other than drug treatment that appears to be helpful.
Acute (Abortive) Pharmacologic Treatment
Migraine attacks can be debilitating. Sufferers are usually motivated to learn the optimal use of medications to control attacks and most readily learn the regimen that works best for them. Recent advances have added important new options for the pharmacologic approach to migraine. This section describes acute (abortive) treatment of migraine attacks, and the next describes preventative treatment. It is important to emphasize that migraines are not cured but can be controlled. Patients have a spectrum of mild, moderate, and severe attacks. Occasional mild migraine attacks may respond to analgesics including acetaminophen, aspirin, or another NSAID. Table 87.3 lists commonly used agents and dosages of these and a number of products that combine analgesics, barbiturates, or caffeine. Most migraine attacks are treated with a triptan, ergotamine tartrate, or an NSAID unless contraindicated, in which case alternate strategies such as opioids or preventative medications are used. Guidelines for acute and preventative migraine treatment have been developed by the U.S. Headache Consortium (19) and by the AAFP/ACP-ASIM (American Academy of Family Physicians, American College of Physicians—American Society of Internal Medicine) (20). Recommendations are similar, however, triptans are recommended as first line therapy in severe migraine by the U.S. Headache Consortium whereas the American Academy of Family Physicians, American College of Physicians—American Society of Internal Medicine (intended for primary care physicians) recommends NSAIDs as first-line treatment for all migraines. Both sets of guidelines recommend education to encourage the patient to be an active participant in his or her care.
Triptans
The triptans are serotonin (5HT1B/1D) receptor agonists that are highly effective migraine-specific medications. These agents, agonists of the serotonin inhibitory receptors on the trigeminal nerve, block neurogenic inflammation and inhibit pain transmission in the trigeminal nucleus caudalis in the brain stem and in the peripheral trigeminal ganglion (21). The major disadvantage of triptans is the high cost. Triptans relieve the associated symptoms of migraine including nausea, vomiting, photophobia, and phonophobia and reduce functional disability (22).
Sumatriptan was the first agent introduced, followed by zolmitriptan, naratriptan, rizatriptan, almotriptan, frovatriptan, and eletriptan. Sumatriptan is available as tablets, an injectable form (stat dose self-injectable), and nasal spray. Zolmitriptan is available as tablet, dissolving tablet, and nasal spray; rizatriptan is available as tablet and dissolving tablets; and the others as tablet only. Sumatriptan was initially recommended at a 25-mg dose. It was later established that the 50-mg dose was comparable to the 100-mg dose, and both were superior to the 25-mg dose (23). Sumatriptan nasal spray is available as 5 and 20 mg. Placebo-controlled trials demonstrated some response with the 5-mg dose, but the 20-mg dose was superior to placebo and is the usual adult dose (24). Administration of a single 6-mg dose of sumatriptan subcutaneously yielded symptom relief in about 75% of patients within 1 hour and in more than 80% within 2 hours (25).
Triptans can be used at any time during a migraine, but they are more effective if taken early in the attack and should be taken at the first indication of migraine, preferably when pain is mild or just beginning. If pain persists, the initial dose can be repeated after 2 hours for oral preparations and nasal spray, and at 1 hour for injectable preparations up to the maximal doses shown in Table 87.3. Triptans can be combined with NSAIDs but not with ergotamine preparations in the same 24 hours (both are vasoconstrictors). Although they are very safe medications in the healthy migraine patient, they should not be used by patients with coronary artery disease (CAD), uncontrolled hypertension, or cerebrovascular disease. Although all triptans are effective in the treatment of migraine, a meta-analysis of the triptans by Ferrari et al. using data from 24,089 patients concluded that eletriptan 40 mg and rizatriptan 10 mg had the highest therapeutic gain
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compared to sumatriptan 100 mg when the end point is pain response at 2 hours. The recurrence rate was highest with rizatriptan (26).
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TABLE 87.3 Drugs for Acute Headache |
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When TTH (see TTH) occurs in migraineurs, sumatriptan 50 mg has been shown to be superior to placebo in producing a pain-free response at 4 hours (56% versus 36%) (27). Table 87.3 presents practical information about available preparations and doses of triptans.
Side Effects
As a class, triptans have similar side effects that include transient paresthesias, sensations of warmth or flushing, tingling, dizziness, somnolence, nausea, chest and neck tightness, and, after subcutaneous administration, injection-site reactions (pain, erythema lasting about 1 hour). In the Ferrari et al. meta-analysis, all oral triptans were similar in side effects except naratriptan and almotriptan, which did not differ from the placebo rate (26).
For patients having excessive side effects with injectable sumatriptan, a lower injected dosage (4 mg) may be prescribed.
Contraindications
The major safety issue is that all triptan compounds have affinity for the 5HT 1 B receptors of the coronary arteries and have the potential to cause constriction of the coronary arteries. All triptans are contraindicated in CAD, stroke, and uncontrolled hypertension. Triptans are not recommended for patients with hemiplegic or basilar-type migraine. Caution is recommended in prescribing triptans for patients who have multiple risk factors for CAD (28). Triptans appear remarkably safe when prescribed to migraine patients without stroke, cardiovascular disease, or multiple vascular risk factors. A large study of 63,575 migraine patients found no association with triptan use and stroke, myocardial infarction (MI), cardiovascular death, or arrhythmia in the 13,664 triptan users versus the migraine controls not receiving triptans (29).
Ergotamine
Ergotamine preparations have largely been replaced by triptans in the treatment of migraine; however they are a reasonable choice when cost is a factor. Ergotamine is available in preparations that permit administration by multiple routes (Table 87.3). Ergotamine has serotonergic and α-adrenergic as well as vasoconstricting properties (21). Dihydroergotamine (DHE), given intravenously or intramuscularly, is used chiefly for treating refractory migraine in an emergency department (ED) or in hospitals (30). DHE is available as a nasal spray, which allows outpatient use and avoids gastrointestinal (GI) side effects.
The ideal route for administering ergotamine is one that is convenient, leads to prompt absorption of the drug, and is not affected by vomiting. Suppository, sublingual, and nasal spray preparations meet these criteria. Ingested tablets can be vomited and are therefore less reliable. Table 87.3 summarizes the traditional recommended schedules for ergotamine administration. The objective of these schedules is to attain a total dosage for oral or rectal administration that is effective but below the dosage that produces nausea and vomiting. Traditionally, this has been accomplished by taking additional doses at 30 and 60 minutes if the first dose is ineffective. An alternative strategy may increase the likelihood of prompt attenuation of headaches. Patients can determine the dosage that produces nausea for them by following the traditional schedule on a headache-free day. The cumulative dosage attained just before nausea is the appropriate initial dosage to take at the onset of future attacks.
A number of points are important in instructing a patient about the use of ergotamine. The patient should understand that ergotamine is used to interrupt the events causing migraine and for maximal benefit ergotamine should be taken at the onset of prodromal symptoms or headache. Waiting for the headache to become well established is a common problem in patients who report no benefit from ergotamine. In order to ensure immediate access to their medicine, patients should be advised to carry some with them at all times. They should be informed that taking more than the recommended maximum daily dosage (Table 87.3) carries the risk of peripheral vasoconstriction in addition to nausea and vomiting. Because ergotamine preparations have a short shelf life, patients should obtain a new supply if they fail to obtain benefit from their medicine or if they have not used it for many months.
Side Effects
Common side effects include abdominal cramps, vertigo, diarrhea, and distal paresthesias; less commonly, syncope, tremor, angina pectoris, and claudication may occur.
Serious adverse effects, including mental status changes, edema, peripheral vascular occlusion, and distal gangrene, can occur if the daily dosage of ergotamine exceeds 6 mg or the weekly dosage exceeds 10 mg on a chronic basis. Patients should therefore be instructed not to use ergotamine more than twice in the same week and no more than 10 mg in 1 week.
Contraindications
The principal contraindications to ergotamine are CAD (angina, history of MI), symptomatic peripheral vascular disease, uncontrolled hypertension, and pregnancy. Ergotamine should not be used in combination with a triptan in the same 24 hours.
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Nonsteroidal Anti-inflammatory Drugs
Oral NSAIDs (aspirin, ibuprofen, naproxen sodium) can be effective at the onset of an acute attack and should be used in full doses (Table 87.3). These drugs are generally more efficacious than simple analgesics (acetaminophen) (19) and narcotics and may be used for acute attacks alone or in conjunction with a triptan or ergotamine.
Narcotic Analgesics
For an established, severe migraine headache not responsive to NSAIDs, a triptan, or ergotamine, simple analgesics are not effective. For this reason, reliable patients may be given small supplies of either codeine (60 mg) or an equipotent narcotic analgesic (see Table 13.1 inChapter 13) to be taken as rescue medication when first-line therapy fails. This measure may save the patient unnecessary trips to the physician's office or an ED. Narcotic agents may be the only option for patients with contraindications to triptans, and who are unable to tolerate or are unresponsive to NSAIDs. Treatment more than 2 to 3 days per week should be avoided as medication overuse headache may result.
Nausea and Vomiting
These migraine symptoms can be treated with promethazine suppositories (25 mg). Metoclopramide is effective as an antiemetic, and may reduce pain in migraine as well. A systematic review concluded that it should be considered as a primary agent in the emergency department treatment of acute migraines (31). For patients with nausea alone, oral antiemetics are useful.
Preventative Pharmacologic Treatment
Preventative therapy for migraine is indicated when migraines are frequent and/or unresponsive to acute treatment, result in disability, and when the patient is at increased risk for migrainous infarction. Known precipitating factors should be eliminated as the initial step in prevention.
The decision regarding preventative medication must be made by the patient, after the distinction between acute and preventative therapy has been clearly explained. For each of the drugs used preventatively for migraine, a long trial period of 2 to 3 months may be necessary to assess effectiveness, and trials with a number of drugs may be needed. Patients should understand that even the best preventative medications do not eliminate all migraine attacks and acute treatment will still be necessary. Generally, effective preventative medications reduce severity and frequency of attacks, and improve response to acute medications. The absolute number of migraines per month may not reflect disability as some migraines are brief and easily controlled, whereas others are of long duration and unpredictably responsive to acute medication. The number of migraines days per month may be a more meaningful parameter in the latter situation. The American Academy of Family Physicians, American College of Physicians—American Society of Internal Medicine outlines the following indications for beginning preventative medication: “1) two or more attacks per month that produce disability lasting 3 or more days per month; 2) contraindication to, or failure of, acute treatments; 3) the use of abortive medication more than twice per week; and 4) the presence of uncommon migraine conditions, including hemiplegic migraine, migraine with prolonged aura, or migrainous infarction” (20).
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TABLE 87.4 Preventative Therapies for Migrainea |
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Table 87.4 lists drugs that have been effective as migraine preventatives, which is adapted from the 2000 Practice Parameter of the American Academy of Neurology (19). These drugs are rated according to efficacy, strength
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of scientific evidence, and side effects. The antiepileptic drug (AED) divalproex sodium is among the drugs receiving the best rating for migraine prevention. Of patients taking divalproex sodium in dosages to achieve levels of 70 to 120 mg/L (500 to 1500), 48% reported headache frequency reduced by 50%, compared to 14% of patients taking placebo (32). Despite this efficacy profile, serious side effects are more likely with divalproex sodium than with other drugs that received this rating. A second AED, topiramate, was approved by the Food and Drug Administration (FDA) for migraine prevention in 2004. In a randomized controlled trial (RCT), topiramate reduced monthly migraine frequency by ≥50% at 100 mg/day (33), which is comparable to the effect of divalproex. Patients who are not helped by the standard preventative medications should be referred to a neurologist or other specialist in migraine.
The following general conclusions can be drawn about migraine preventative medication therapy:
Alternative/Complementary Measures to Prevent Migraine.
The herbal remedy feverfew has not been shown convincingly superior to placebo (34). Acupuncture has been shown possibly superior to sham treatment (35). Homeopathic remedies have not been shown to be efficacious in the limited clinical trials available for review (36). Magnesium (37) and vitamin B2 (riboflavin) (38) have been used based in small trials and have low side-effect profiles, but evidence for efficacy is limited. Petasites hybridus root (butterbur) was studied in a randomized controlled trial in 245 patients with migraine. After 4 months of treatment the dose of 75 mg b.i.d. was superior to both placebo and to a lower dose and side effects were minimal, primarily burping (39). Chapter 5 contains additional information about nontraditional remedies.
Pregnancy and Migraine
From 50% to 80% of patients with migraine will experience remission of their headaches during pregnancy, especially after the first trimester (40,41). A small number may experience onset of migraine or worsening of headache during pregnancy. Nonpharmacologic measures to reduce or treat attacks in pregnancy include stress reduction, relaxation techniques, cognitive behavioral therapy, and avoidance of triggers. Acetaminophen and prochlorperazine are of low risk and can be used throughout pregnancy for acute attacks. Narcotics can be used judiciously, but should not be used in high doses at term in order to avoid respiratory depression in the newborn. Codeine with acetaminophen is often used. Current recommendations are to avoid ergotamines and triptans during pregnancy (41). Two systematic reviews (42,43) examining the use of sumatriptan in pregnancy have failed to show any impact of sumatriptan on pregnancy outcomes, but there are no RCTs to date, and the evidence is deemed insufficient to rule out a small increase in risk for birth defects. Avoidance of triptans during pregnancy is currently recommended unless the benefit to the mother outweighs the risks to the fetus. Aspirin and NSAIDs are relatively safe, but should be avoided in the last trimester. For women with intractable and frequent migraines, particularly with vomiting, preventative therapy may be necessary. β-Blockers are considered safe, however, intrauterine growth retardation and newborn bradycardia may occur if used in the last trimester. Some of the conventional preventative therapies are absolutely contraindicated, i.e., valproic acid (18).
Patients with Intractable Migraine Headaches
A small number of migraine sufferers have intractable and disabling headaches for which no effective regimen can be found despite trials of all available pharmacologic regimens. For a further assessment and consideration of other therapeutic options, these patients should be referred to a neurologist or headache specialist.
Cluster Headache
Classification and Diagnostic Criteria
Cluster headache is classified separately from migraine because of its distinct clinical characteristics and different therapy. Some of the most common previous names include Horton headache, histamine headache, Sluder
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neuralgia, and migrainous cranial neuralgia. Criteria for the diagnosis of cluster headache (4) include the following:
Attacks occur in clusters extending over days to weeks, giving the syndrome its name. Most cluster episodes last 4 to 6 weeks and are followed by long pain-free intervals. The intervals between episodes range from 3 months to 5 years, and occasionally longer. Most patients have one or two episodes per year; permanent remission occurs in a minority of patients. In a small proportion of patients, the pattern converts from episodic to chronic or from chronic to episodic (44).
The attacks are stereotyped. A typical attack begins with sudden unilateral stabbing or burning pain in the eye, orbit, and cheek. The pain is excruciating and strictly unilateral. Unlike patients with migraine, patients with cluster headaches are usually agitated and often pace the floor during the attack. The autonomic features are usually prominent, but may be absent. The same side is always involved during a cluster period, and almost always the same side as in previous attacks. If attacks switch sides, the diagnosis of cluster headache should be reconsidered. Attacks may last from 15 minutes to 3 hours (most often 30 to 40 minutes), and they tend to occur at the same time each day, commonly at night after the patient has gone to bed. As alcohol, nitrates, and vasodilator drugs may induce attacks, patients should be asked about concurrent use of alcohol and drugs.
Except during an attack, when the unilateral findings described are present, the physical examination in patients with cluster headache is normal.
Differential Diagnosis
Cluster headache must be distinguished from trigeminal neuralgia (discussed under Facial Pain Syndromes), acute glaucoma (by the presence of miosis, normal tonometry, and no visual impairment), rhinosinusitis (by lack of history of upper respiratory infection, lack of purulent rhinorrhea or sinus tenderness, and negative findings on CT), peripheral dental abscess (by the absence of tenderness on tooth percussion), and atypical facial neuralgia (see Facial Pain Syndromes).
Epidemiology
Cluster headache is much less common than migraine. It occurs predominantly in middle-age men and is associated with smoking cigarettes. The male-to-female gender ratio has been reported as 2.1 to 6.7:1 with an increase in women in more recent studies. Onset usually occurs between the ages of 20 and 50 years of age. Cluster has not been considered an inherited condition; however, studies have revealed a family history in 4% to 7% of patients (45).
Treatment
Acute (Abortive) Treatment
Attacks are short, lasting 15 to 180 minutes and, therefore, oral drug treatment may be ineffective in ameliorating an acute episode (46). When available, 100% oxygen, administered for approximately 15 minutes at a flow rate of 7 L/minute, may abort an attack. In a double-blind trial, about half of the subjects responded within 10 minutes to 100% oxygen but not to placebo (room air) given through a non-rebreathing face mask (47). The therapeutic effect of oxygen may result from its vasoconstrictor action. Injectable sumatriptan provides the most rapid onset of action of the triptans. Subcutaneous sumatriptan, used as described previously for migraine, was shown to decrease the severity of headache in approximately 75% of cluster attacks as compared with placebo (48). A triptan nasal spray (sumatriptan or zolmitriptan) is a reasonable choice in patients who cannot self-inject sumatriptan. Ergotamine, administered sublingually, may also be effective abortive therapy for cluster headaches. A sublingual preparation of ergotamine containing 2 mg (Table 87.3) may be given at the beginning of the attack and repeated twice at 30-minute intervals. No more than 6 mg should be taken in a 24-hour period, or more than 10 mg per week.
Preventative Treatment
Cluster attacks consist of frequent, excruciating headache and require preventative medication. These drugs include verapamil, lithium, divalproex sodium, and topiramate in dosages described for migraine prevention. Verapamil is well tolerated and considered by many as first line therapy. Lithium carbonate appears uniquely effective in cluster headache at doses of 300 to 900 mg/day, which results in serum levels lower than usually required for bipolar disease (45). Chapter 24 describes the use of this drug in detail.
Prednisone, beginning at 60 to 80 mg/day and tapering over 2 weeks, may shorten the duration of a cluster episode and decreases the severity and frequency of the
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attacks (46). A maximal effect occurs within 2 or 3 days after initiation of therapy. (See additional information on prescribing and tapering of corticosteroids in Chapter 81.) Cluster is a very painful condition. If the patient does not respond to initial treatment, prompt referral to a headache specialist is recommended.
Sinus Headache
Chapter 33 discusses diagnosis and management of rhinosinusitis in detail, which is classified as acute, subacute, and chronic. Headache is a minor criterion in the American Academy of Otolaryngology–Head and Neck Surgery diagnostic criteria for rhinosinusitis. The major criteria, of which two or more (or one major plus two minor criteria) must be present to diagnose rhinosinusitis include: purulence in the nasal cavity, facial pain/pressure (must be accompanied by another major criteria), nasal obstruction, fever (acute only), and anosmia/hyposmia (49). Further confounding the problem of diagnosis is the high rate of incidental abnormalities on CT scanning of the sinuses in asymptomatic individuals (50).
The International Classification of Headache Disorders II diagnostic criteria for headache attributed to rhinosinusitis (4) include:
Sphenoid sinusitis, although an uncommon cause of sinusitis, is unique in that it is associated with significant morbidity if not diagnosed. Headache is usually unremitting, unchanging in location, and moderately severe, aggravated by activities such as stooping or coughing (51). (See Chapter 33 for further discussion/treatment.)
Chronic sinusitis is often cited as the reason for their headaches by patients requesting repeated courses of antibiotics for episodic headaches. This belief occurs as pain is located over the sinus regions. In a group of self-identified sinus headache patients, 70% met all the criteria for migraine and 28% met all but one criterion and were considered to have migrainous headaches (probable migraine). These patients reported nasal stuffiness (74%), runny nose, and weather change-related onset (45%); all of these symptoms/triggers are associated with migraine (52). Therefore, patients who have recurrent headaches with facial pain and nasal congestion and who do not have purulent nasal discharge or other features of rhinosinusitis most likely have migraine.
Exertional Headache (Cough, Sneeze, Orgasm)
The distinguishing feature of exertional headache is sudden, almost instantaneous, onset of headache related to exertion including coughing, sneezing, straining, bending, running, lifting, and sexual orgasm. It may last from seconds to hours to days. Exertional headaches are usually benign, but may be related to intracranial disease. Exertional headache is associated with Arnold-Chiari malformations in about 40% of cases (4).
Exertional headache must be differentiated from the sentinel headache of subarachnoid hemorrhage (SAH). The latter is usually, but not always, persistent and associated with fever, stiff neck, syncope, and focal neurologic signs. Exertional headaches can be quite severe, but are usually brief and recur with the trigger activity. Distinguishing a first episode of exertional headache from the sentinel headache of SAH is not usually possible on clinical grounds. Brain imaging with CT or MRI scan (see Chapter 86) should be considered at first presentation of exertional headache. For a patient with a negative scan but a clinical presentation strongly suggestive of SAH a lumbar puncture is required.
If imaging findings and lumbar puncture results are normal, the benign nature of the condition should be explained to the patient. The patient may avoid the activity or treat with an NSAID (Table 87.3) prior to the headache-provoking activity.
Sudden-Onset Unprovoked Severe Headache
Sudden-onset, unprovoked severe headache (thunderclap headache) is uncommon but alarming. The headache reaches it peak in seconds. In a large prospective study based in general practice, 37% of patients with this presentation had serious central nervous system disease (25% had subarachnoid hemorrhage). Fewer than 10% of those with subarachnoid hemorrhage had a history of sentinel headaches. In 1 year of followup, none of those with undiagnosed (imaging and lumbar puncture [LP] negative) sudden headache experienced subarachnoid hemorrhage (53). Patients with sudden-onset, severe headache should be referred immediately to a hospital emergency room for prompt evaluation.
Headache Caused by Medications
Headache is a side effect of many drugs, usually occurring in a predictable temporal relationship to ingestion of the substance. It is important to routinely ask about new drugs
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when evaluating a headache of recent onset. Migraine patients have a more severe immediate headache and reliably develop a delayed migraine type headache with some drugs/substances such as nitric oxide donors (nitroglycerin) or phosphodiesterase (PDE) inhibitors (sildenafil, dipyridamole) (54). Headache may occur with vasodilator drugs, but the effect is not predictable.
Management depends on the indications for the drug and severity of the headache. Some patients, if informed of the possibility of headache, choose to take the drug anyway; this is particularly true of administration of nitrates for angina. For the long-acting nitrates, dosage reduction may effectively reduce headache for some patients, whereas alternative antianginal treatment is needed for others (see Chapter 62).
Headache in Acute Febrile Illnesses
Acute febrile illnesses may cause headaches that remit when the illness resolves. A febrile patient in whom the headache is the major symptom and in whom nuchal rigidity or other manifestation of meningeal irritation is present requires a cerebrospinal fluid (CSF) examination to exclude meningitis (see Chapter 86).
Giant Cell Arteritis and Polymyalgia Rheumatica
Giant cell arteritis (GCA) is a chronic vasculitis affecting large and medium arteries throughout the body. Clinical manifestations are usually caused by involvement of the aorta and extracranial branches of the carotid artery, and the most common symptom is headache. GCA has also been called temporal arteritis (TA), because temporal headaches and a positive superficial temporal artery biopsy are the findings that are most typical of the disease. The cause of GCA is unknown.
Polymyalgia rheumatica (PMR) is a debilitating condition of older people that manifests with morning stiffness and aching of the neck and proximal musculature. It precedes, accompanies, or follows the onset of GCA in approximately 50% of patients with GCA. In approximately 75% to 80% of patients with PMR in the United States and Europe, GCA does not occur (55). In patients who develop both GCA and PMR, the two syndromes may occur at the same time or GCA may begin months to years after the onset of PMR symptoms. PMR and GCA may be different manifestations of the same vasculitic disorder (56).
Epidemiology
GCA and PMR are almost exclusively diseases of people older than 50 years of age; the average age at onset is 65 to 70 years. Both are uncommon among African Americans, Hispanics, and Asians. They are most common in people of northern European descent, and they are more common in women than in men. It is estimated that the prevalence of GCA is about 200 per 100,000 Americans older than 50 years of age (57). There are no population-based studies of frequency of PMR in the United States; however, it is estimated that the incidence and prevalence rates for PMR are about two or three times higher than the rates for GCA.
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TABLE 87.5 Clinical Features of Giant Cell Arteritis |
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Manifestations
GCA presents with nonspecific symptoms of fever, anorexia, weight loss, myalgias, and headache. The headache is often temporal; however, it can be frontal, occipital, parietal, or holocephalic. It may be made worse by hair brushing, resting the head on a pillow, or exposure to cold. Table 87.5 lists the most important factors suggesting the diagnosis of GCA. It is important to inquire specifically about pain (claudication) associated with chewing, swallowing, and arm or tongue motion, because these symptoms are highly suggestive of GCA. The combination of one or more of the findings listed in Table 87.5 in a patient older than 50 years of age with a new headache is sufficient to suspect GCA.
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PMR is insidious in onset. The chief complaints are aching and stiffness of the shoulder girdle and, less commonly, of the thigh muscles. These symptoms can make it particularly hard for the patient to get up in the morning. Associated low-grade fever, weight loss, and anorexia are common. On physical examination, there may be some tenderness of the shoulder and neck muscles, but there is no significant loss of muscle strength.
Diagnosis
If GCA or PMR is suspected, the erythrocyte sedimentation rate (ESR) measured by the Westergren method is the most useful screening test. The majority of patients have a markedly elevated ESR (often 100 mL/hr or greater). Because the upper limit of normal for people older than 60 years of age may be as high as 40 mL/hr, an ESR of 40 to 60 mL/hr is less informative than a very high ESR. Unlike other chronic inflammatory diseases, GCA and PMR are not associated with autoantibody production or abnormalities in complement factors or immunoglobulin levels.
Definitive diagnosis of GCA is made with a superficial temporal arteritis (TA) biopsy. Examination of serial sections of a long specimen is essential as the typical histologic changes (inflammatory cells, edema, giant cells) are patchy in distribution. In addition to a positive TA biopsy, the American College of Rheumatology has designated four other features that support the diagnosis of GCA: onset after 50 years of age, new localized headache, Westergren ESR greater than 50 mL/hr, and TA tenderness or decreased TA pulse. The presence of three of the five features is considered sufficient evidence to make the clinical diagnosis of GCA (58). One retrospective study reported the feature most predictive of a diagnostic TA biopsy was the presence of either visual symptoms, a TA that is abnormal on examination, or constitutional symptoms (59).
Patient Experience
TA biopsy can be done in an ambulatory surgery facility by a general surgeon, ophthalmologist, vascular surgeon, plastic surgeon, or neurosurgeon. The local scalp hair is shaved, the skin is anesthetized, and a large segment of artery (>2 cm) is excised. The procedure requires about one-half hour and there are no serious sequelae.
The diagnosis of PMR is based on the combination of the typical symptoms, a high ESR, and exclusion of other explanations for the patient's symptoms. Normocytic anemia is common. Muscle enzyme levels, electromyography, and muscle histology are all normal. If a patient with typical PMR has manifestations suggesting GCA (Table 87.5), TA biopsy is indicated, because the recommended dosages of corticosteroids for the two conditions are different.
Course and Treatment
Treatment recommendations are based on comparisons of untreated patients with patients treated with corticosteroids. The most serious complication of GCA is unilateral or bilateral vision loss caused by ischemic optic neuropathy. Treatment with corticosteroids appears to prevent vision loss which occurs in 20% to 30% of untreated patients. Although the symptoms of GCA and PMR may respond to aspirin and other NSAIDs, these agents have not been shown to prevent the progressive vasculitis in GCA that can lead to vision loss.
Giant Cell Arteritis
If the diagnosis of GCA is suspected, corticosteroid treatment should be initiated immediately and the TA biopsy should be obtained within 3 to 4 days. If the patient has vision loss that is thought to be from GCA, it is recommended that treatment with steroids should be initiated intravenously (60). The initial oral treatment is prednisone (40 to 60 mg once per day) for 4 to 6 weeks. Within 1 to 3 days, symptoms usually remit entirely and there is a significant decrease in the ESR. After 2 to 3 weeks, the prednisone should be slowly tapered until a dosage of 7.5 to 10 mg daily has been reached (56). Further tapering and duration of treatment depend on the clinical response and ESR. A 2-year course of prednisone is usually recommended. Some authors, who have documented GCA relapse after discontinuation of treatment, recommend lifelong maintenance treatment with low-dose prednisone, especially for patients who have no intolerable side effects from treatment (61). One controlled trial found that combined prednisone and methotrexate treatment for 2 years reduced the frequency of relapse after discontinuation when compared to standard prednisone-only treatment (62).
Polymyalgia Rheumatica
Treatment is begun with prednisone 10 to 20 mg daily, tapered to a daily maintenance dosage of 5 to 7.5 mg after several weeks. Treatment is continued for approximately 2 years, with gradual discontinuation at the end of that time. The symptoms of PMR, as well as the ESR, respond to this regimen dramatically, often within the first 24 hours. PMR recurs in some patients, within months to years after discontinuing prednisone; these patients usually respond to a second course of treatment.
Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)
Idiopathic intracranial hypertension (IIH) is a condition of unknown cause characterized by the following: signs and symptoms of increased intracranial pressure (headache, papilledema, nausea, vomiting, and transient visual obscurations); elevated CSF pressure >25 cm of water;
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normal CSF analysis; and the absence of a mass lesion, hydrocephalus, or venous sinus thrombosis on brain imaging (63). This condition has had several names including pseudotumor and benign increased intracranial pressure. The signs and symptoms are due to increased intracranial pressure (ICP). Focal neurologic signs are absent with the exception of sixth nerve palsy, which produces diplopia.
Several factors have been associated with IIH including obesity, menstrual irregularity, steroid therapy or withdrawal, oral contraceptives, and a variety of medications and substances, including tetracycline, and vitamin A.
Manifestations
This is an uncommon condition with an incidence of 3.5 per 100,000 in women 15 to 44 years old and 19.3 per 100,000 in women 20 to 44 years old who are obese. It is nine times more frequent in women than men although before puberty boys and girls are equally affected (63). The typical patient is an obese young woman who develops progressively more severe headaches, nausea, vomiting, dizziness, and transiently blurred vision. Vision loss lasting seconds at a time can be monocular or binocular and is thought to be because of disc edema. Pulsatile tinnitus described as “hearing my heartbeat,” or whooshing sounds is present in 60% of patients (64). The onset may be abrupt or gradual. Headache is usually bilateral, retro-ocular, constant, and often more severe in the morning, aggravated by coughing, straining, or changing position, and by eye movement. The diagnosis is suggested strongly by daily headache in an obese woman with transient visual obscurations, pulsatile tinnitus, and papilledema without focal neurologic signs. Visual fields may be constricted and the blind spot enlarged. If untreated, vision loss may result.
Differential Diagnosis
The diagnosis of IIH is always one of exclusion. Important considerations in the differential diagnosis are intracranial mass, hydrocephalus, and cerebral venous sinus thrombosis. To exclude an intracranial mass or hydrocephalus, a contrast brain MRI scan (see Chapter 86) should be obtained. For women at increased risk of cerebral venous thrombosis (taking oral contraceptives, are postpartum, or, have hypercoagulopathy), brain magnetic resonance venography (MRV) should also be obtained. In IIH, the MRI/MRV is normal. After a negative MRI, a lumbar puncture should be performed (see Chapter 86). The lumbar puncture is essential in the diagnosis. The opening pressure is high (250 mm H2O or more); the analysis of the fluid is normal (include cell count, glucose, protein, cytology, fungal and tuberculosis cultures, and some recommend bacterial cultures) (63). In a very obese woman with a history of amenorrhea for many months, it is also important to consider pregnancy-induced hypertension (toxemia), which is ruled out by a negative pregnancy test.
Treatment and Course
With treatment most patients recover completely from IIH within several weeks or months; however, some patients require ongoing therapy to control headaches and prevent vision loss. Referral to a neurologist and ophthalmologist is almost always necessary as the treatment is specialized and visual fields will need to be formally monitored. In obese patients, weight reduction is recommended.
The goal of therapy is to relieve symptoms by reducing intracranial pressure. At the time of the diagnostic lumbar puncture, enough fluid can be removed to reduce the closing pressure to normal, usually about 25 to 35 mL of fluid. The carbonic anhydrase inhibitor, acetazolamide (500-mg sustained-release capsule up to effect or side effects) has been the traditional therapy as CSF production is believed to be directly inhibited. If the patient remains asymptomatic and the papilledema resolves, acetazolamide can be tapered and discontinued. The use of corticosteroids to treat IIH is controversial. For patients with continued headache, visual impairment, and papilledema, surgical procedures (CSF shunting via a lumboperitoneal shunt or surgical incision of the optic nerve sheath) are sometimes necessary (63). Treatment of these patients is difficult and requires the consultation of neurologists, ophthalmologists, and neurosurgeons experienced in handling this disorder.
Posttraumatic (Postconcussive) Headache
Manifestations
Headache is a common symptom after head and neck trauma and usually occurs within a close temporal relationship to the injury. A number of symptoms, collectively termed the postconcussion syndrome (PCS), occur after traumatic brain injury (TBI): headache, vertigo (often positional; see Chapter 89), light-headedness or giddiness, poor concentration and memory, lack of energy, irritability, anxiety, light and sound sensitivity, change in taste or smell, and insomnia (65). When no structural injury has occurred, the causal mechanism responsible for these symptoms remains unknown.
Headache is common and, typically begins within 24 hours as a dull, constant ache that may wax and wane throughout the day or become concentrated in one location. It may be worsened by sneezing, coughing, stooping, straining, or rapid head motions and changes in body position. Typically, postconcussive symptoms resolve over weeks or months, however, some patients remain symptomatic at 1 year. When persistent, headache may take on migrainous features.
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Differential Diagnosis
Subdural Hematoma and Other Expanding Mass Lesions
Headache and nonspecific complaints can occur with chronic subdural hematomas and other slowly expanding mass lesions. Brain imaging either with CT or MRI (see Chapter 86) can be used to evaluate persistent headache after trauma.
Carotid or Vertebral Artery Dissection
Headache occurs on the side of the dissection. Carotid dissections are associated with partial Horner syndrome (miosis, ptosis). Both carotid and vertebral dissections may be accompanied by delayed focal cerebral ischemic symptoms (stroke or TIA, see Chapter 91).
Pre-existing Migraine or Tension Headaches
Head trauma may worsen a pre-existing primary headache disorder such as migraine or tension-type headache.
Objective Tests
A literature search for guidelines for imaging in mild TBI/concussion did not produce guidelines for decision making for patients presenting to the office. Emergency room guidelines for imaging in mild TBI (66) advise against skull film radiographs, and do not recommend which patients should have a noncontrast CT scan. The guidelines advised that CT is not indicated in patients who do not have headache. It can therefore be reasonably recommended to obtain noncontrast CT in patients with mild TBI and headache. Guidelines from the American Academy of Neurology in mild TBI (PCS) because of sports injury recommend brain CT or MRI when headache or other symptoms persist for longer than 7 days or if the symptoms worsen (67). In the absence of other guidelines, it would be reasonable to extrapolate this recommendation to posttraumatic headache due to other injuries.
Treatment
Most patients with posttraumatic headaches recover without specific treatment. There are no randomized controlled trials for posttraumatic headache treatment. Agents used to treat tension-type headache or migraine can reasonably be tried (Table 87.4).
Low Cerebrospinal Fluid Pressure Headache
Low-pressure headache from persistent leakage of CSF occurs most commonly after lumbar puncture. It may occur spontaneously or after trauma and is believed to result from dural tears (68). The headache is markedly positional, brought on by sitting or standing, and relieved almost entirely by lying down. The headache is usually generalized and nausea and dizziness are common nonspecific accompaniments. There are no focal neurologic symptoms or signs, and the patient is afebrile. Brain imaging with MRI may be normal, or positive for diffuse meningeal enhancement, descent of the cerebellar tonsils, decrease in basal cisterns, and for hygromas or chronic subdural hematomas.
The majority of post–lumbar puncture and posttraumatic CSF leaks close spontaneously. Simple medical management includes bedrest, hydration, and ingestion of caffeine. Patients with persistent low pressure headaches can be referred to an anesthesiologist for epidural blood patch. Because of the risk of meningitis, any patient with a suspected persistent CSF leak should be referred to a neurologist or neurosurgeon for further evaluation.
Characteristics of Headache Caused by a Mass Lesion
For both the headache sufferer and the physician, concern about the possibility of a brain tumor often dominates the situation. Important clues to the presence of an intracranial mass lesion are: focal neurologic signs/symptoms, change in mental status, or a seizure. A new headache disorder in a patient older than 50 years of age is suggestive of a secondary headache disorder.
A number of nonspecific features may be clues to the presence of an intracranial mass lesion:
When one or more of these historical features are present or focal neurologic signs are found on examination, the patient should be evaluated with brain MRI with contrast (see Chapter 86). If MRI is positive for intracranial disease, the patient should be referred to a neurologist or neurosurgeon for definitive care.
Facial Pain Syndromes
Trigeminal Neuralgia (Tic Douloureux)
Manifestations
Trigeminal neuralgia is an idiopathic disorder seen most commonly in patients older than 40 years of age, most of
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them elderly. It has several distinguishing features: The pain occurs in a branch of the trigeminal nerve, is severe, shooting, electric-like, and lasts a few seconds to a minute. The patient's face usually contorts with the pain, and the patient may find it impossible to control his/her emotional response. Between attacks the patient is usually pain free, although some patients have a dull ache in the affected area. The interval between paroxysms is usually at least 2 or 3 minutes. The frequency of paroxysms is highly variable; some patients have hundreds each day.
The pain is usually felt in the structures innervated by the second and third divisions of the trigeminal nerve (lips, gums, cheek, chin). The pain is unilateral, does not cross the midline, and never involves both sides of the face simultaneously. The patient often can identify trigger points on the face or in the mouth that, when touched (even by contact with a gust of cold air) precipitate pain (69).
Some patients with trigeminal neuralgia have areas of slightly decreased sensation that may be difficult to distinguish from normal; however, there is no objective decrease in sensation.
Other, less common syndromes with paroxysms of lancinating pain include glossopharyngeal neuralgia (pharynx pain) and occipital neuralgia (posterior head pain).
Differential Diagnosis
A syndrome identical or similar to idiopathic trigeminal neuralgia, i.e., secondary trigeminal neuralgia, can be produced by a number of conditions such as multiple sclerosis, acoustic or trigeminal neuroma, aneurysm, meningioma, brainstem infarction or syrinx, and arterial compression. These conditions should be considered, particularly if the patient is younger than 40 years of age, the pain is in the upper division of the trigeminal nerve (forehead and eye), pain is bilateral, or there are abnormalities on neurologic examination.
Treatment
In a patient with a typical clinical presentation and a normal neurologic examination, medical therapy can be initiated without further workup. Patients are in excruciating pain and should be evaluated and treated promptly. If medical therapy is ineffective, or if there are any atypical features, referral to a neurologist is appropriate.
Carbamazepine, widely recognized as the best initial treatment, is usually started at a low dose (100 mg) twice daily. Increases of 100 to 200 mg a day can be made every 3 days until pain relief is obtained. The usual daily dosage is between 400 to 800 mg. Some patients need higher (1500 mg/day) dosages; in these cases, blood levels may be necessary to monitor compliance (69). Most patients can expect excellent to satisfactory relief with carbamazepine. The pharmacokinetics of carbamazepine are complex because of autoinduction with subsequent change in the half life which is complete at 3 to 5 weeks. This may account for apparent loss of efficacy, which can be reversed with an increase in dosage or an increase in dosing frequency. Side effects of the drug include nausea, vomiting, ataxia, vertigo, and transient leukopenia. The most serious side effects are persistent leukopenia and aplastic anemia. A complete blood count and liver function tests are recommended at baseline and at periodic intervals dependent on the clinical course. Trigeminal neuralgia can remit spontaneously. Patients who remain pain free can have their medication slowly tapered periodically to determine if they are in remission
If the patient fails to improve with carbamazepine or fails to tolerate the drug, the muscle relaxant baclofen in doses of 30 to 80 mg/day can be tried. A patient whose symptoms cannot be controlled with these medications should be referred for neurologic consultation.
Atypical Facial Pain
Atypical facial pain is a collective term for a variety of painful facial symptoms that do not meet the diagnostic criteria for a recognized entity. These patients should be referred for neurologic consultation to be evaluated for more obscure syndromes.
Temporomandibular Joint Syndrome
Some patients complaining of headache have pain brought on by motion of the jaw and tenderness of the temporomandibular joint. Chapter 112 describes the epidemiology, course, and management of this syndrome.
Specific References*
For annotated General References and resources related to this chapter, visit http://www.hopkinsbayview.org/PAMreferences.
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