Headaches

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Chapter 9 Headaches

In the most widely accepted categorization, the International Headache Society (IHS) recognizes three major categories: Primary Headaches, Secondary Headaches, and Cranial Neuralgias. Primary headaches include tension-type, migraine, and cluster headaches. Although not life-threatening, Primary Headaches may create excruciating pain, incapacitate patients, and, with frequent attacks, reduce their quality of life. Neurologists generally diagnose these headaches not by physical findings or laboratory tests, which are characteristically normal, but by their distinctive symptoms.

Secondary Headaches, on the other hand, are often manifestations of an underlying serious, sometimes life-threatening, illness. This category includes temporal arteritis, intracranial mass lesions, idiopathic intracranial hypertension (pseudotumor cerebri), meningitis, subarachnoid hemorrhage, and postconcussion headaches (see head trauma, Chapter 22). Unlike the diagnosis of primary headaches, the diagnosis of secondary headaches typically rests on their clinical context, physical findings, or laboratory abnormalities.

Primary Headaches

Tension-Type Headache

Tension-type headache (TTH), previously called “tension headache,” is the common headache disorder characterized by intermittent dull pain, lasting between 30 minutes and 7 days, usually located bilaterally in the frontal or cervical regions. Patients have only pain. They do not have other symptoms that typify migraine, such as photophobia, hyperacusis, phonophobia, nausea, vomiting, or other autonomic disturbance. This headache plagues women more than men and often affects multiple family members. Patients with TTH tolerate their pain and usually go about their business. (In contrast, patients who are unable to function during headaches probably have migraine.)

TTH has traditionally been attributed to contraction of the scalp, neck, and face muscles (Fig. 9-1), as well as emotional “tension.” Fatigue, cervical spondylosis, bright light, loud noise, and, at some level, emotional factors allegedly produce or precipitate TTH. However, because studies have demonstrated that this headache results from neither muscle contractions nor psychological tension, the designation “muscle contraction” or “tension” probably represents a misnomer. The term “tension-type” headache is more appropriate. In fact, many neurologists place this headache at the opposite end of a headache spectrum from migraine, where both result from a common, but unknown, physiological disorder.

FIGURE 9-1 Tension-type headaches produce a bandlike, squeezing, symmetric pressure at the neck, temples, or forehead.

Treatment

Neurologists generally first assure themselves and their patients that the headache does not represent a brain tumor or other potentially fatal illness, which is frequently an unspoken fear. On the other hand, these headaches are liable to become a chronic, intractable, demoralizing painful condition. Risk factors for chronicity or other poor outcome include comorbid migraine, being unmarried, and sleep disorders.

For headaches that occur less than twice a week, neurologists usually suggest “acute therapy” – medicines taken at the headache’s onset to abort an incipient attack or reverse a full-blown one. Over-the-counter medicines, such as aspirin, aspirin–caffeine compounds, acetaminophen, and nonsteroidal anti-inflammatory drugs (NSAIDs), usually suffice. Patients keep these medicines readily available in the car, at work, and in pocketbooks to take at any inkling of a headache. However, physicians should be mindful that their daily use often leads to chronic daily headache (see later).

Neurologists often recommend “preventive therapy” – medicines taken daily – under several circumstances: if headaches occur more frequently than two or three times per week, acute therapy is ineffective, or analgesic consumption becomes excessive. For example, even if patients have no history of depression, neurologists often prescribe small nighttime doses of a tricyclic antidepressant (TCA). Similarly, even if patients have no history of epilepsy, neurologists often prescribe certain antiepileptic drugs (AEDs), such as valproate/divalproex (Depakote) or topiramate (Topamax). However, they usually avoid prescribing benzodiazepines. As if to confirm that muscle contraction does not cause TTH, botulinum toxin injections into scalp and cervical muscles, even though they reduce muscle spasm, fail to alleviate these headaches.

In children and adolescents, relaxation and cognitive-behavioral therapy (CBT) reduce the frequency and severity of chronic headache. In adults, insight-oriented psychotherapy and psychoanalysis, when directed toward headaches, do not alleviate them, but may provide insight, reduce anxiety, treat depression, and offer other benefits. Stress management therapy, especially when combined with a TCA, provides modest help.

Migraine

Neurologists have said, “Whereas tension type headaches are boring in their sameness, migraine headaches are typically rich in symptoms.” In clinical practice, the core criteria for migraine consist of episodic, disabling headaches associated with nausea and photophobia. The nonheadache symptoms, in fact, often overshadow or replace the headache. The headaches’ qualities – throbbing pain and unilateral location – are typical and included in the IHS criteria (Box 9-1).

Approximately 12% of all Americans suffer from migraine. Not only do women suffer from migraine three times more frequently than men, their migraines are more severe. Migraine may first appear in childhood, but most often not until adolescence or early adulthood. The prevalence increases until age 40 years. Although migraine symptoms are complex and variable, they are usually consistent from attack to attack for the individual patient.

Neurologists grossly divide migraine into two subtypes – defined primarily by the presence or absence of an aura.

Migraine with Aura

Migraine with aura, previously labeled classic migraine, affects only about 20–30% of migraine patients. The aura, which can represent almost any symptom of cortex or brain dysfunction, typically precedes or accompanies the headache (Box 9-2). The headache itself is similar to the headache in migraine without an aura (see later).

Auras usually appear gradually and then evolve over 5–20 minutes, persist for less than 1 hour, and evaporate with the headache’s onset. They characteristically consist of a transient visual phenomenon, but sometimes a simple olfactory hallucination. Instead of a disturbance in one of the special senses, aura occasionally consists of language impairment similar to aphasia, sensory misperception, or personality change. In children, but not adults, recurrent colic or “cyclic abdominal pain” with nausea and vomiting may constitute a migraine variant, but not technically an aura.

By far the commonest migraine auras are visual hallucinations (see Chapter 12). They usually consist of a graying of a region of the visual field (scotoma) (Fig. 9-2, A), flashing zigzag lines (scintillating or fortification scotomata) (Fig. 9-2, B), crescents of brilliant colors (Fig. 9-2, C), tubular vision, or distortion of objects (metamorphopsia). Unlike visual auras that represent several different neurologic conditions (see Box 12-1), migraine auras most often involve the simultaneous appearance of positive phenomena, such as scintillations, and negative ones, such as opaque areas. Finally, instead of sensory auras, some migraineurs experience premonitory somatic symptoms, such as fatigue, stiff neck, yawning, hunger, and thirst. These patients can frequently predict their impending migraine hours to days before onset.

FIGURE 9-2 A, These drawings by an artist who suffers from migraine show the typical visual obscurations of a scotoma that precedes the headache phase of her migraines. In both cases, she loses a small circular area near the center of vision. As occurs with most migraineurs, she says that, although the aura is only gray and has a simple shape, it mesmerizes her. B, The patient who drew this aura, a scintillating scotoma, wrote, “In the early stages, the area within the lights is somewhat shaded. Later, as the figure widens, you can peer right through the area. Eventually, it gets so wide that it disappears.” This typical scotoma consists of an angular, brightly lit margin and an opaque interior that begins as a star and expands into a crescent. She somehow calculated that it scintillated at 8–12 Hz. Neurologists refer to auras with angular edges as fortification scotomas because of their similarity to ancient military fortresses. C, A 30-year-old woman artist in her first trimester of pregnancy had several migraine headaches that were heralded by this scotoma. Each began as a blue dot and, over 20 minutes, enlarged to a crescent of brightly shimmering, multicolored dots. When the crescent’s intensity peaked, she was so dazzled that she lost her vision and was unable to think clearly. D, Having patients, especially children, draw what they “see” before a headache has great diagnostic value. One adolescent reconstructed this “visual hallucination” using his computer.

Migraine without Aura

Previously labeled common migraine, migraine without aura affects about 75% of migraine patients. In other words, most individuals with migraine do not have an aura. Arising without warning, their headaches are initially throbbing and located predominantly behind a temple (temporal) or around or behind one eye (periorbital or retro-orbital), but usually on only one side of the head (hemicranial) (Fig. 9-3). In the majority of cases, the side of the headache switches within and between attacks. Individual attacks usually occur episodically and last 4–72 hours. Frequent attacks may evolve into a dull, symmetric, and continual pain – chronic daily headache – that mimics TTH.

FIGURE 9-3 Patients with migraine usually have throbbing hemicranial headaches that may either move to the other side of the head or become generalized.

For patients and neurologists, what really distinguishes migraine from TTH are migraine’s nonheadache symptoms, including sensory hypersensitivity (photophobia and phonophobia), autonomic dysfunction (nausea and vomiting), and disability. In common terms, people with migraine typically have episodes of moderately severe headaches accompanied by nausea; and during a painful attack, they gravitate to dark, quiet places.

During migraine attacks, patients often have dysphoria and inattentiveness that can mimic depression, complex partial seizures, and other neurologic disturbances (Box 9-3). Most patients withdraw during an attack, but some become feverishly active. Many then tend to drink large quantities of water or crave certain foods or sweets, particularly chocolate. Children often become confused and overactive. After an attack clears, especially when it ends with sleep, migraine sufferers may experience a sense of tranquility or even euphoria.

An additional point of contrast to TTH is that migraine attacks typically begin in the early morning rather than the afternoon. In fact, they often have their onset during rapid eye movement (REM) sleep, which predominates in the several hours before awakening (see Chapter 17). Sometimes migraines begin exclusively during sleep (nocturnal migraine). No matter when a migraine attack has begun, naturally occurring or medication-induced sleep characteristically cures it.

In women, migraine often first develops at menarche, recurs premenstrually, and is aggravated by some oral contraceptives. Most women with migraine report that their attacks are most likely to occur immediately before or at the beginning of their menses, and about 10% of them suffer migraines exclusively at this time. During pregnancy, about 70% of women with migraine experience dramatic relief, but usually only during their second or third trimesters. However, pregnancy can also have adverse effects. About 10% of women with migraine experience their first attack during pregnancy. Furthermore, 10–20% of pregnant women with migraine have more frequent or more severe attacks than usual. Nevertheless, pregnant women beset by migraine are no more likely than ones free of migraine to suffer miscarriage, eclampsia, or fetal malformations. Although postpartum headaches may represent a recurrence of migraine, they may instead represent more serious conditions, such as cortical vein thrombosis, complication of epidural anesthesia, or pituitary infarction. Postmenopausal women usually enjoy improvement in their migraine frequency and severity.

Another important characteristic of migraine is that it can be precipitated – in susceptible individuals – by certain factors or “triggers,” such as skipping meals or fasting on religious holidays, too little or excessive sleep, menses, psychologic or occupational stress, overexertion, head trauma, and alcoholic drinks. (Alcohol can also provoke attacks of cluster headaches [see later].) Red wine and brandy are the alcoholic drinks most likely to trigger an attack, with vodka and white wine the least likely.

To the chagrin of many patients, migraine attacks often coincide with weekends and the start of a vacation. Many of the factors associated with these holidays likely contribute to this paradox: withdrawal from work-related stress, anxieties associated with leisure periods, too little sleep, sleeping later than usual (which extends REM periods and does not allow the customary morning cup of coffee [see later]), and lavish meals, which typically include foods spiced with monosodium glutamate (MSG) accompanied by wine.

Psychiatric Comorbidity

Contrary to old views, migraine is not restricted to individuals in upper-income brackets or among those who are rigid, perfectionist, and competitive. Neurologists consider “migraine personality” an outmoded concept.

Depression is strongly comorbid with migraine and the conditions appear reciprocal. Major depression increases the risk of migraine but not of other severe headaches. Similarly, unlike other headache disorders, migraine increases the risk of major depression up to four times the normal population. Migraineurs are also more likely to carry the diagnosis of generalized anxiety disorder, panic disorder, and bipolar disorder. Studies differ as to the effect of comorbid depression on the frequency or disability of migraine. In an effect that seems to be restricted to women, adverse life events increase headache frequency.

Therapy for patients with migraine and comorbid depression should start with simple behavioral advice, such as getting sufficient sleep on a regular schedule, exercising moderately, avoiding alcohol and drugs, and keeping a “headache diary” (see later). CBT and biofeedback, as an adjunct to medication, may be helpful.

TCAs are not only effective for treating migraine comorbid with depression, they are more effective than selective serotonin or norepinephrine reuptake inhibitors (SSRIs or SNRIs) for treating migraine with or without comorbid depression. SSRIs and SNRIs are less effective than TCAs, and, when administered concurrently with one of the popular anti-migraine serotonin (5-hydroxytryptamine [5HT]) agonists, such as a “triptan” (see later) or dihydroergotamine (DHE), they carry a low but often-cited risk of producing the serotonin syndrome (see Chapter 6).

Recognizing the neurologic basis of migraine, the preliminary version of the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) would place headaches on Axis III. If patients fabricate reports of migraine to obtain opioids or other tangible benefit, the diagnosis would be Factitious Disorder or Malingering.

Other Subtypes of Migraine

Childhood migraine is not simply migraine in “short adults.” Compared to migraine in adults, in childhood migraine the headache is more severe, but briefer (frequently less than 2 hours), and less likely to be unilateral (only one-third of cases). However, as with migraine in adults, the nonheadache components may overshadow the headache. For example, childhood migraine often produces episodes of confusion, incoherence, or agitation. In addition, it frequently leaves children incapacitated by nausea and vomiting. Physicians caring for children with such episodes may consider mitochondrial encephalopathy as an alternative, although rare, diagnosis (see Chapter 6). Pediatric neurologists also consider mitochondrial encephalopathy, along with hemiplegic migraine (see later), in the differential diagnosis of transient hemiparesis in a child with headaches.

Children are particularly susceptible to migraine variants. In basilar-type migraine, the headache is accompanied or even overshadowed by ataxia, vertigo, dysarthria, or diplopia – symptoms that reflect brain dysfunction in the basilar artery distribution (the cerebellum, brainstem, and posterior cerebrum [see Fig. 11-2]). In addition, when basilar migraine impairs the temporal lobes, children as well as adults may experience temporary generalized memory impairment, e.g., transient global amnesia (see Chapter 11). Hemiplegic migraine, another variant, is defined by hemiparesis of various grades often accompanied by hemiparesthesia, aphasia, or other cortical symptoms. All these symptoms usually precede or occur with an otherwise typical migraine headache, but they may also develop without any headache or other migraine symptom. Thus, in evaluating a patient who has had transient hemiparesis, the physician might consider hemiplegic migraine along with transient ischemic attacks, stroke, postictal (Todd’s) hemiparesis, and conversion disorder.

In familial hemiplegic migraine, patients develop transient hemiparesis before or during the headache. This variant of migraine is transmitted in an autosomal dominant pattern by a genetic abnormality on chromosome 19. The basic mechanism is a calcium channel abnormality – a “channelopathy.” Other channelopathies include myotonic dystrophy, spinocerebellar ataxia type 6 (also transmitted by a mutation on chromosome 19), and varieties of epilepsy.

Stroke occasionally complicates migraine. Of its variants, migraine with aura serves as the most powerful risk factor for stroke. Female migraine patients who both smoke cigarettes and use oral contraceptives are particularly at risk of stroke.

Migraine-Like Conditions: Food-Induced Headaches

Neurologists look at certain foods and medications as both a cause of nonspecific headache and a trigger of migraine. However, other than alcohol, the role of food is overemphasized. It precipitates migraine or other headache in only about 15% of patients.

The two clearest examples of foods precipitating headaches occur in the Chinese restaurant syndrome, where the offending agent is MSG, and the hot dog headache, where nitrites, used in many processed meats, are the offending agent. A different situation is the icecream headache, where any very cold food that touches the pharynx triggers a headache. Some people – but fewer than generally assumed – develop migraine-like headaches after eating foods containing tyramine, such as ripened cheese, or ones containing phenylethylamine, such as chocolate. In view of chocolate’s tendency in some individuals to precipitate attacks, migraine sufferers’ frequent chocolate craving before an attack is ironic. Nevertheless, migraine sufferers should probably avoid the “four Cs”: chocolate, cheese, Chinese food, and alcohol (C₃H₅OH).

On the other hand, people who miss their customary morning coffee typically develop the caffeine withdrawal syndrome that consists of moderate to severe headache often accompanied by anxiety and depression. Although this syndrome is almost synonymous with coffee deprivation, withdrawal of other caffeine-containing beverages or caffeine-containing medications can precipitate it (see Chapter 17). Herein lies a dilemma: sudden withdrawal of caffeine can cause the withdrawal syndrome, but excessive caffeine leads to irritability, palpitations, and gastric acidity. Moreover, excessive caffeine also is a risk factor for transforming migraine to chronic daily headache.

Medication-Induced Headaches

Although opioids may suppress headaches, neurologists have remained wary of their leading to drug-seeking behavior (see Chapter 14). In the majority of patients receiving opioid treatment, emergency room visits and hospitalizations decrease, but their headaches and disability persist. Nevertheless, neurologists often prescribe them in limited, controlled doses when vasoactive or serotoninergic medications carry too many risks, such as for pregnant or elderly patients.

Triptans, the 5HT_1B/1D serotonin receptor agonists, include eletriptan (Relpax), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig). They are rapidly effective for moderate to severe migraine and some are available as injections, sublingual wafers, and nasal sprays. The variety of forms allows patients to administer their medicines without delay, even when in public or beset by nausea. Women with menstrually related migraine might suppress attacks by taking a triptan or NSAID for the several days before menses commence or during the days of their cycle when their headaches occur – catamenial migraine.

Ergotamine and DHE, which are primarily vasoconstrictors, are also rapidly effective. Although widely used decades ago, triptans have supplanted them. Excessive use of the vasoconstrictors may lead to persistent, excessive vasoconstriction (ergotism) in the coronary arteries, digits, and elsewhere. In another caveat, because vasoconstrictors might precipitate a miscarriage or cause fetal malformations, ergotamine and DHE, unlike triptans, are unequivocally contraindicated in pregnant women. Finally, administration of either a triptan or vasoconstrictor to patients already under treatment with an SSRI or SNRI risks causing the serotonin syndrome.

Many of these migraine medications have the same worrisome side effect as those used to treat TTH. Their frequent use – as little as two to three times a week – may lead not to cure but to chronic daily headache.

Nausea and vomiting not only constitute symptoms of migraine, but they may also be side effects of DHE or another antimigraine medicine. Whatever their cause or severity, nausea and vomiting prevent gastric absorption of orally administered medicines. Many migraine sufferers thus require a parenterally administered antiemetic, such as metoclopramide (Reglan). One caveat remains: dopamine-blocking antiemetics may cause dystonic reactions identical to those induced by dopamine-blocking antipsychotics (see Chapter 18). Thus, neurologists often prophylactically administer diphenhydramine (Benadryl) along with those antiemetics.

Migraine attacks lasting more than 3 days (status migrainosus) usually lead to prostration, prolonged painful distress, and dehydration. Patients suffering from such prolonged, refractory illness benefit substantially from parenteral medication, intravenous fluids, antiemetics, and a quiet, dark refuge. Neurologists must often hospitalize patients in status migrainosus. Medically supervised withdrawal from over-the-counter medications, opioids, or even excessive conventional antimigraine medicines may also require hospitalization.

Preventive Treatment

Neurologists prescribe preventive treatment under several circumstances: migraine occurring more than four times a month; migraine causing 3–4 days of disability per month; acute medicines losing their effectiveness; or patients taking excessive medicine. For realistic purposes, neurologists expect to decrease their patients’ migraine frequency and intensity by 50%. Most preventive medicines fall into three categories: antidepressants, antihypertensives, and antiepileptics.

TCAs, particularly amitriptyline and nortriptyline, reduce the severity, frequency, and duration of migraine. Apart from their mood-elevating effect, TCAs may ameliorate migraine because they suppress REM sleep, which is the phase when migraine attacks tend to develop. In addition, because TCAs enhance serotonin, they are analgesic (see Chapter 14). As most migraine patients are young and require only small doses of TCAs compared to those used to treat depression, the side effects of TCAs in this situation are rarely a problem. Interestingly, for preventing migraine, SSRIs are ineffective compared to TCAs.

Neurologists often prescribe β-blockers for migraine prophylaxis, as well as for treatment of essential tremor (see Chapter 18). However, they avoid prescribing β-blockers to migraine patients with comorbid depression because of their tendency to precipitate or exacerbate mood disorders.

Certain AEDs, such as topiramate and valproate, offer preventive treatment for migraine, as well as for neuropathic pain and epilepsy. Valproate is suitable for migraine sufferers with or without mood disorders. It may suppress migraine by reducing 5-HT neurons firing in the dorsal raphe nucleus or by altering trigeminal GABA_A receptors in the meningeal blood vessels. However, its side effects, especially weight gain, often preclude its use.

Numerous medications in other categories show some benefit for chronic migraine. Among them, botulinum toxin injections reduce the frequency or severity of migraines that both last 4 hours or longer and occur at least 15 times a month. Indeed, botulinum toxin injections reduce the impact of migraines and improve a patient’s quality of life. Finally, naturopaths have long hailed acupuncture as a successful preventive treatment for migraines. While there is no difference between the efficacies of the “true” acupuncture group in comparison to the “sham” acupuncture control group, up to 50% of patients in both groups can have improvement in their headache frequency and severity.

Chronic Daily Headache

When patients report headaches, each lasting 4 hours or longer, for at least 15 days each month for at least 3 months, neurologists diagnose chronic daily headache. Patients may arrive at this state via several different routes. For years, they may have had migraine or TTH – to the extent that they can be differentiated (Table 9-1) – that transformed from episodes to a daily or nearly every day affliction. Alternatively, individuals, especially children, develop chronic daily headache after a lifetime of having few, if any, headaches, a situation that neurologists label New Daily Persistent Headache (NDPH). Specific conditions, such as a posttraumatic syndrome or psychiatric disturbances, may also lead or contribute to daily headache. Moreover, whatever the route, overuse of analgesics or other medicines often has paved the way to a chronic daily headache.

TABLE 9-1 Comparison of Tension-Type and Migraine Headaches

	Tension-type	Migraine
Location	Bilateral	Hemicranial*
Nature	Dull ache	Throbbing*
Severity	Slight–moderate	Moderate–severe
Associated symptoms	None	Nausea, hyperacusis, photophobia
Behavior	Continues working	Seeks seclusion
Effect of alcohol	Reduces headache	Worsens headache

^*In approximately half of patients, at least at onset.

Patients with chronic daily headache typically describe generalized, waxing and waning, dull, pressing, and nonpulsatile pain, which is usually only mild to moderate in severity. Nevertheless, the discomfort, if not pain, is incapacitating. Headaches that transform from episodic to chronic not only lose any distinctive pain qualities, they shed associated features, such as scotoma and autonomic dysfunction. The headaches, which blend, vary, and recur, have lost their punch.

Children and adolescents with chronic daily headaches usually have had no history of medication overuse, but otherwise medication overuse is overwhelmingly the most powerful risk factor. The medicines most commonly implicated are aspirin–butalbital–caffeine compounds (e.g., Fiorinal), triptans, NSAIDs, benzodiazepines, and opioids. Some medicines are more dangerous than others. For example, use of triptans or opioids more frequently than 10 days a month leads to these headaches in less than 2 years, but frequent use of nonopioid analgesics requires almost 5 years.

Other risk factors include obesity, head trauma, low socioeconomic status, disability, major stressful life events, and several psychiatric conditions, particularly depression and anxiety. Risk factors for adolescents are primarily depression and anxiety.

In terms of treatment, all of the patient’s physicians must work together to prevent medication overuse and look for underlying psychiatric disorders – some obvious, some not. Injection of botulinum toxin into the head and neck muscles has a therapeutic role (see Chapter 18), and TCAs, valproate, and topiramate may help; however, chronic daily headache generally resists treatment. Nonpharmacologic treatments of this disorder, which are of unproven benefit, include modification of lifestyle, behavior therapy, and elimination of precipitating factors.

When they attribute chronic daily headache to a medication overuse, neurologists of course attempt to eliminate the culprit. However, abruptly stopping a headache medicine may lead to withdrawal symptoms that can be as troublesome as opioid withdrawal. Neurologists often hospitalize chronic daily headache patients with comorbid depression and those who have a history of excessive use of any medicine.

Cluster Headaches

An individual cluster headache consists of searing pain in one eye and its adjacent, periorbital region. Ipsilateral eye tearing, conjunctival injection, nasal congestion, and a partial Horner syndrome (Figs 9-4 and 12-16) typically accompany the pain. Thus, neurologists sometimes classify this headache as trigeminal autonomic cephalalgia. Each headache lasts only 45–90 minutes, but to the patient, the attack seems interminable. The pain’s severity often drives patients to agitation, restlessness, and thoughts of suicide.

FIGURE 9-4 This 43-year-old man with cluster headaches suffers from nightly right-sided unrelenting severe, stabbing unilateral periorbital pain for 45 minutes to 3 hours accompanied by ipsilateral tearing and nasal discharge, along with ptosis and miosis (a partial Horner syndrome). Note that the ptosis prompts compensatory elevation of the eyebrow.

The appellation “cluster headaches” derives from the tendency of these headaches to strike in groups (clusters) that consist of 1–8 attacks daily for several months. Compared to patients with other primary headache disorders, the demography of cluster headache patients has a unique distribution. This disorder affects men, typically between the ages of 20 and 40 years, 6–8 times more frequently than women.

Most cluster attacks have a predictable, cyclic pattern. For example, some patients develop attacks every spring or fall. During clusters, headaches do not occur randomly throughout the day. Most strike between 9:00 PM and 9:00 AM and one-half of them develop during REM sleep. Alcohol characteristically precipitates an attack. While cluster headaches respond to calcium-channel blockers and triptans, inhaling 100% high-flow oxygen will abort them. Thus, administering oxygen can be diagnostic as well as therapeutic.

Compared to migraines, cluster headaches are more predictable and briefer, but more intense. Also unlike migraine, only local autonomic signs accompany cluster headaches. The headaches are not preceded by an aura, have no accompanying systemic autonomic signs, and are not alleviated by bedrest or seclusion. Cluster patients are typically young to middle-aged men who, during a cluster, are susceptible to alcohol and vulnerable during REM sleep. Like migraine, cluster has a familial tendency, but it is weak.

Treatment

Orally administered acute migraine medications are ineffective mostly because each cluster headache’s abrupt, unexpected onset and relatively short duration do not allow enough time for the patient to swallow a medicine and absorb it. However, injections of sumatriptan or DHE injections and oxygen inhalation at 8–10 L/min. may abort them. Preventive medicines include lithium, steroids, verapamil, and valproic acid. (Neurologists introduced lithium treatment for cluster headaches because these headaches, like bipolar disease, follow a cyclic pattern and affect middle-aged individuals.)

Secondary Headaches

Temporal Arteritis / Giant Cell Arteritis

Temporal arteritis (giant cell arteritis) is a disease of unknown etiology in which the temporal arteries, other cranial arteries, and often also medium-sized arteries throughout the body develop overt inflammation. Because the disease is systemic and histologic examination of affected arteries reveals giant cells, giant cell arteritis is more of an appropriate term than the more restrictive one, temporal arteritis.

Because patients are almost always older than 55 years, temporal arteritis is one of the several headache conditions that predominantly affect the elderly (Box 9-4). The headache itself usually consists of dull and continual pain located in one or both temples. Jaw pain on chewing (“jaw claudication”) is frequent and almost pathognomonic. In advanced cases, the temporal arteries are tender and red from induration. Signs of systemic illness, such as malaise, myalgias, arthralgias, low-grade fever, and weight loss, characteristically accompany the headache and reflect the systemic nature of the illness. In fact, polymyalgia rheumatica or another rheumatologic disorder occurs concurrently in about 25% of cases of giant cell arteritis.

Box 9-4

Causes of Headaches Predominantly in the Elderly

Brain tumors: glioblastoma, metastases

Cervical spondylosis

Vasodilators and other medications

Postherpetic neuralgia

Subdural hematomas after little or no trauma

Temporal arteritis (giant cell arteritis)

Trigeminal neuralgia

Because untreated arterial inflammation leads to arterial occlusion, serious complications may develop if the diagnosis of giant cell arteritis were delayed. Two dreaded complications, which stem from occlusions of the ophthalmic, ciliary, and cerebral arteries, are blindness and stroke.

In over 90% of cases, the erythrocyte sedimentation rate (ESR) rises above 40 mm. C-reactive protein, a more sensitive indicator for this diagnosis, may be abnormally elevated in patients with normal ESR. A temporal artery biopsy remains the definitive test, but it is sometimes unnecessary, hazardous, or impractical. Timely treatment with high-dose steroids will relieve the headaches, alleviate systemic symptoms, and prevent the complications.

Intracranial Mass Lesions

The first symptom of brain tumors and chronic subdural hematomas – common mass lesions (see Chapters 19 and 20) – is most often headaches. However, the headaches’ qualities are nonspecific and potentially misleading. For example, brain tumor headaches usually mimic TTH. Also, when headaches are unilateral, they are on the side opposite the tumor in 20% of cases. Even though brain tumor headaches notoriously begin during early-morning REM sleep and awaken patients, that pattern develops in less than half of cases. Moreover, numerous other headaches display the same early-morning onset, including migraine, cluster, carbon dioxide retention, sleep apnea, and caffeine withdrawal.

At least subtle cognitive and personality changes accompany headaches from mass lesions. Even if not present initially, lateralized signs usually develop within 8 weeks. However, overt signs of increased intracranial pressure – papilledema and stupor – usually do not develop until late in the course, if at all.

To avoid missing a diagnosis of brain tumor and to calm fears, which are often unstated, of patients, their families, and medical colleagues, neurologists readily order computed tomography (CT) or magnetic resonance imaging (MRI). In addition, for patients with headaches beginning after 55 years, they order an ESR.

Chronic Meningitis

Chronic meningitis, like mass lesions, produces weeks of a dull, continual headache accompanied by progressive cognitive impairment and personality changes. However, with chronic meningitis, symptoms and signs of systemic infectious illness may predominate. Meningeal inflammation at the base of the brain causes additional, distinctive features. The inflammation chokes various cranial nerves, leading to facial palsy (from seventh cranial nerve injury), hearing impairment (eighth nerve), or extraocular muscle palsy (third, fourth, or sixth nerves).

A variety of infectious agents can cause chronic meningitis, but generally only in susceptible individuals. For example, Cryptococcus commonly causes meningitis almost only in patients who have an impaired immune system. With almost any variety of chronic meningitis, CT or MRI typically reveals enlargement of all four ventricles because impaired reabsorption of cerebrospinal fluid (CSF) through the arachnoid villa leads to communicating hydrocephalus. The CSF pressure is elevated and its analysis shows lymphocytic pleocytosis, low glucose concentration, and elevated protein concentration (see Table 20-1).

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

Neurologists have begun to change the popular terms “pseudotumor cerebri” and “benign intracranial hypertension” to idiopathic intracranial hypertension. This term better acknowledges the unknown etiology and serious nature of this condition.

Idiopathic intracranial hypertension, which originates in cerebral edema, develops predominantly in young, obese women who have menstrual irregularity. Although reports from several decades ago claimed that consuming excessive vitamin A, outdated tetracycline, or polar bear meat was the cause of several cases, recent studies found that the cause in many cases is elevated intracranial venous sinus pressure – often from venous sinus occlusion.

Whatever its etiology, idiopathic intracranial hypertension gives rise, as in so many other conditions, to a dull, generalized headache. This condition’s distinctive feature is papilledema. If untreated, the papilledema leads to an enlarged blind spot within each visual field and eventually blindness from optic atrophy (see Chapter 12). Increased intracranial pressure also sometimes stretches and then damages one or both of the abducens (sixth) cranial nerves. The abducens nerve palsy leads, in turn, to unilateral or bilateral inward eye deviation because of the unopposed, intact third cranial nerves (see Chapter 4).

Although many idiopathic intracranial hypertension patients suffer from severe headaches and have florid papilledema, their neurologic examination is otherwise surprisingly normal. In fact, idiopathic intracranial hypertension is probably the most common cause of papilledema.

Neurologists, aware of potential causes of headaches and papilledema, routinely order not only MRI, but also MR studies of the intracranial veins (MRV). In pseudotumor cerebri, CT and MRI typically show cerebral swelling and compressed, small ventricles that neurologists label “slit-like.” MRV often shows slowing or occlusion of intracranial venous drainage.

CSF pressure is typically greater than 300 mm H₂O, and often reaches levels greater than 400 mm. The CSF protein concentration, as though edema fluid diluted the CSF, falls to low levels; however the CSF glucose concentration remains normal and no cells appear, i.e., the CSF stays acellular. Treatment usually consists of carbonic anhydrase inhibitors and diuretics. Neurologists frequently monitor treatment with repeated lumbar punctures (LPs) to measure the pressure and drain CSF. In refractory cases, neurosurgeons can decompress the ventricular system by installing CSF shunts or performing an optic nerve sheath fenestration.

Post Dural Puncture Headache (PDPH)

Headache is a common complication of LP or “dural puncture” that appears up to 5 days following the procedure. It probably originates in continued leakage of CSF through a tear in the lumbar dura and subsequently low intracranial pressure. Neurologists usually refer to the condition as “post-LP headache,” but the term post dural puncture headache, while wordier, is more accurate and inclusive.

As though withdrawal of CSF lets the brain rest unprotected against the inside of the skull, the patient sitting upright or even rapidly turning the head and neck exacerbates the headache. Neck stiffness or tinnitus often accompanies the headache and prostration.

Surprisingly, patient rehydration and prolonged bedrest after the LP do not lower rates of PDPH. While neurologists traditionally prescribe bedrest, fluids, and caffeine, the best treatment is an epidural “blood patch” that consists of 20–30 mL of the patient’s own blood injected into the epidural space to seal the tear in the dura.

Bacterial Meningitis, Herpes Encephalitis, and Subarachnoid Hemorrhage

Bacterial meningitis and subarachnoid hemorrhage produce commonly occurring, life-threatening illnesses characterized initially by headache. Meningococcus and Pneumococcus, the most common causes of bacterial meningitis, often spread in a small epidemic pattern among children and young adults in confined areas, such as college dormitories and military training camps. In addition, pneumococcal meningitis has a predilection for older, debilitated individuals in whom meningitis and many other infectious illnesses have an insidious onset and subtle signs. Whichever the infectious agent, meningitis usually causes the development, over several hours to several days, of malaise, fever, photophobia, nuchal rigidity, and moderate to severe headache. The headaches are usually generalized, but sometimes they are retro-orbital or nuchal. When physicians suspect bacterial meningitis, they routinely examine the CSF (see Table 20-1) and, if indicated, intravenously administer penicillin or other antibiotic. Vaccinations against meningococcal and pneumococcal infections provide a great deal of protection to students, recruits, and nursing home residents.

Viral infections of the brain (viral encephalitis) also cause headaches. With a few exceptions, these headaches and other symptoms are usually nonspecific and run a more benign course than bacterial infections. However, in contrast to almost all other forms of encephalitis that develop in the United States, herpes simplex encephalitis has distinct clinical features. The virus, herpes simplex, is the most frequent cause of serious, nonepidemic viral encephalitis. It has a remarkable predilection for the frontal inferior surface of the brain and attacks the undersurface of both the frontal and temporal lobes. Like most other viral infections, herpes simplex encephalitis causes fever, somnolence, and delirium. In addition, because the virus attacks the temporal lobes and thus damages the limbic system, it routinely causes complex partial seizures and memory impairment (amnesia). Bilateral temporal lobe damage in some patients may lead to the human variety of the Klüver–Bucy syndrome (see Chapter 16). Frontal and temporal lobe damage may lead to language impairment (aphasia) and frontal lobe behavioral disorders (see Chapter 7). In herpes simplex and other forms of encephalitis, an LP, CT, MRI, and sometimes an electroencephalogram are the most useful diagnostic tests.

Another cause of severe, acutely occurring headache is subarachnoid hemorrhage, which usually results from a ruptured cerebral aneurysm. Cerebral artery aneurysms – often shaped like “berries” (berry aneurysms) – usually develop in the arteries comprising the circle of Willis (see Fig. 11-2 and Chapter 20). If the arteries fuse incompletely in utero, weak junctions may eventually form an aneurysm. When an aneurysm ruptures, blood shoots into the subarachnoid space, which surrounds the brainstem and cerebral hemispheres and normally contains crystal-clear CSF. Depending on the aneurysm’s location and size, it may also send a jet of blood into the brain. Beginning almost immediately after a subarachnoid hemorrhage, a CT usually reveals blood in the subarachnoid space. Several hours after the hemorrhage, the CSF color turns from red to yellow (xanthochromic).

Subarachnoid hemorrhages often occur during exertion, including exercise, straining at stool, and sexual intercourse. Whether or not preceded by exertion, subarachnoid hemorrhages typically cause severe headache, prostration, and nuchal rigidity – symptoms similar to those of bacterial meningitis. Although most patients with a subarachnoid hemorrhage have symptoms that indicate serious intracranial pathology, sentinel bleeds (“leaks”) or otherwise atypical subarachnoid hemorrhages are not as dramatic and often escape detection. For example, neurologists sometimes reasonably misdiagnose them as migraine headache.