Migraine headaches: Diagnosis and management

Transcription

1 Optometry (2009) 80, Migraine headaches: Diagnosis and management Hilla Abel, O.D. Private practice, Rego Park, New York. KEYWORDS Migraine; Aura; Headache; Glaucoma; Photopsia; Transient ischemic attack Abstract BACKGROUND: Patients often complain to their optometrist about their headaches, of which migraines are a common type. They may ask if their pain is from visual causes or whether the visual auras they experience are normal. METHODS: The literature on migraine is reviewed to provide the optometrist with current information to manage these patients. RESULTS: Included in the review are migraine epidemiology, pathophysiology, categorization, clinical presentation, diagnosis, and treatment. CONCLUSION: Optometrists can help their migraine patients with a thorough examination, advice, proper referrals, and optical management when appropriate. Optometry 2009;80: Migraine is a common 1 neurovascular 2 disorder encompassing a clinical spectrum of symptoms. Migraine is considered one of the primary headache types, although migraines can be diagnosed if an aura is present in the absence of head pain. 3 Visual aura, the photopsia associated with some migraines, is the most common form of aura, 3 making migraine a headache of particular interest to optometrists. Because migraine is a historically underdiagnosed condition, 4 the optometrist is in a prime position to identify cases and aid these patients with proper management. Undiagnosed migraineurs may first present to their optometrist looking for answers to their visual symptoms. Even when lacking visual symptoms, patients with headaches often seek consultation with optometrists to investigate whether uncorrected refractive error is a contributing factor, and they may be referred by another physician for this reason. One study of migraine prevalence in optometric practice found that 178 of 1,000 consecutive patients had a history of migraine; of those, 7 presented to the examination with migraine related Corresponding author: Hilla Abel, O.D., NY Empire Medical, Queens Blvd., Suite 1K, Rego Park, New York hilla_abel@hotmail.com to their chief complaint. 5 This article provides the background needed for managing this patient population, covering migraine epidemiology, pathophysiology, categorization, clinical presentation, diagnosis, and treatment. Epidemiology In the adult population, migraine affects more women than men, with an estimated 18.2% of women and 6.5% of men suffering from migraine. 1 However, until puberty, migraines are more common in boys than girls, because the average onset of migraines is earlier in males than females. 6 In addition to differences in prevalence between genders, differences among races exist as well. A U.S. study examining the relative prevalence of migraineurs among 3 racial groups found migraine to be most common in whites followed by blacks and lowest in Asian-Americans. Interestingly, the associated symptoms of migraine can differ among racial groups. For example, blacks are less likely than others to report nausea and more likely to report photophobia and phonophobia. 7 Migraines tend to run in families, with a reported family history in approximately one third of migraineurs. 5 Twin studies have consistently shown higher concordance rates /09/$ -see front matter Ó 2009 American Optometric Association. All rights reserved. doi: /j.optm

2 Hilla Abel Review Article 139 for migraine among identical twins than among fraternal twins. 8 In addition, 3 migraine genes have been found, all of them specifically for familial hemiplegic migraine, 9 but it is anticipated that more genes will be discovered. Given their debilitating nature, migraines are a significant source of distraction from work and family obligations. Migraine prevalence in both men and women peaks during the ages of 25 to 55, 10 prime years for work and child rearing. Fifty-three percent of migraineurs have reported that their headaches cause them impairment in activities or the need for bed rest. Thirty-one percent of migraineurs have reported a missed work or school day in a given 3-month period. 1 Most migraineurs (52% to 73%) report that their work and family relationships are adversely affected because of their migraine attacks. 11 In addition, migraine poses a burden on the health care system: A recent study has estimated an annual cost of $11.07 billion in the direct medical care of insured Americans, including the cost of prescription drugs and care in inpatient, outpatient, and emergency settings. 12 Pathophysiology Migraine pathophysiology is an actively researched area of study. Although enormous progress has been made in understanding aspects of the underlying mechanism, a definitive pathway has not been described. For decades, the pain associated with migraines was believed to be caused by constriction and dilation of cranial blood vessels, as described by Harold Wolff in the 1950s and 1960s. 13 Modern techniques have disputed Wolff s theory and shown that although vascular changes are involved, they are secondary to neuronal mechanisms. Current understanding of the mechanism of the migraine headache centers on key anatomic players, collectively known as the trigeminovascular system. Specifically, this term refers to the interaction between the ophthalmic division of the trigeminal nerve with the dura mater and cranial blood vessels. 14 The presynaptic terminals of the trigeminal nerve contain neuropeptides, including substance P and calcitonin gene-related peptide, which, when released, stimulate a neurogenic inflammation of the blood vessels. This entails dilation of the blood vessels, plasma protein exudation, and mast cell activation and degranulation. 2 The brainstem plays a modulatory role in migraine mechanism and is related via its housing of the caudal nucleus of the trigeminal nerve. 14 A recent theory on the origins of pain in migraine involves the notion of the sensitization of neurons, referring to the phenomenon in which a sensory stimulus elicits an abnormally large neuronal response. Peripheral sensitization, taking place at the junction of the trigeminal terminus and the meningeal blood vessels, may account for the throbbing pain of migraine headache. In turn, peripheral sensitization may stimulate a central sensitization process of abnormal excitability in the caudal nucleus of the trigeminal nerve, resulting in innocuous stimuli being perceived as painful, or allodynia. Allodynia is experienced after the onset of headache pain, consistent with the proposed mechanism of peripheral sensitization triggering central sensitization. 15,16 The mechanisms explaining aura, the focal neurologic symptoms associated with migraine, are better understood than those of migraine headaches. The underlying process of migraine aura is known as cortical spreading depression, described by Aristides Leão in 1943 based on studies of the rabbit cortex. Leão found that a laboratory stimulus causes a brief neuronal excitation, followed by a neuronal depression spreading at a slow rate of 3 mm/min across the cortex, which corresponds to a spreading oligemia (decrease in blood flow) of cerebral vasculature. Also in the 1940s, Karl Lashley characterized his own migrainous visual aura and determined that its spread in the visual field correlates to a movement of 3 mm/min across the visual cortex. 17 Because aura precedes or coincides with headache pain, it has been postulated that cortical spreading depression triggers the headache pain mechanism. However, it is also known that aura and headache can exist independently of one another. Thus, the mechanisms underlying aura and headache pain may represent parallel processes. 18 Migraine types Some patients will call any headache a migraine. Headaches, however, are defined precisely. In 2004, the International Headache Society published the second edition of the International Classification of Headache Disorders (ICHD-II). This work and its predecessor standardized scattered headache terminology that had accumulated over the centuries. The migraine section of the classification outline can be found in Table 1. Select categories are summarized below. Migraine without aura (1.1) was previously known as common migraine and is experienced by a large majority of migraineurs. 19 The ICHD-II requires 5 criteria (A through E) to diagnose migraine without aura in an adult (see Table 2). Thus, a migraine headache is typically, but not necessarily, a severe throbbing headache on one side of the head. In addition to the head pain itself, the associated symptoms of photophobia, phonophobia, nausea, and vomiting can be bothersome or even debilitating. During attacks, migraineurs tend to avoid physical activities and often will seek rest in a quiet, dark room. Migraine with aura (1.2) is an umbrella term encompassing the type of migraine that used to be called classic migraine. Nearly 18% of migraineurs exclusively experience migraine with aura, and an additional 13.1% experience a combination of migraine with and without aura. 19 There are 6 subtypes of migraine in this category, all of which feature aura. Aura is a focal neurologic symptom that develops gradually. Often, it is a binocular visual

3 140 Optometry, Vol 80, No 3, March 2009 Table 1 Migraine classification with corresponding International Headache Society codes 1. Migraine 1.1 Migraine without aura 1.2 Migraine with aura Typical aura with migraine headache Typical aura with nonmigraine headache Typical aura without headache Familial hemiplegic migraine (FHM) Sporadic hemiplegic migraine Basilar-type migraine 1.3 Childhood periodic syndromes that are commonly precursors of migraine Cyclical vomiting Abdominal migraine Benign paroxysmal vertigo of childhood 1.4 Retinal migraine 1.5 Complications of migraine Chronic migraine Status migrainosus Persistent aura without infarction Migrainous infarction Migraine-triggered seizure 1.6 Probable migraine Probable migraine without aura Probable migraine with aura Probable chronic migraine Reproduced with permission of the International Headache Society. 3 symptom, but can also be a unilateral sensory symptom, a speech disturbance, a motor weakness, or a combination. Two attacks are necessary for diagnosis. 3 Three subtypes of migraine with aura include typical aura. Aura in these attacks is one or more focal neurologic symptoms including visual, sensory, or speech disturbances; any other type of motor weakness is specifically excluded. Aura symptoms usually last between 5 and 60 minutes. In typical aura with migraine headache (1.2.1), the patient experiences aura before or concurrent with a migraine headache. In typical aura with nonmigraine headache (1.2.2), aura is paired with another type of headache, such as a cluster headache. The third subtype, typical aura without headache (1.2.3), features aura in the absence of head pain. 3 Typical aura with migraine headache is the most common form of migraine with aura. Both migraine headache, fulfilling criteria B through E (see Table 2), and aura are present. In addition to aura, some patients may experience blurred vision. 3 Typical aura without headache is the updated terminology for what has been previously termed acephalgic (acephalic) migraine and in some cases ocular or ophthalmic migraine. 20 This migraine subtype is noteworthy to the eye care practitioner, with a prevalence of 2.9% of males and 8.6% of females in a primary eye care setting. 21 Lacking a headache, patients may turn to their optometrist to diagnose the visual symptoms. Most often, typical aura Table 2 ICHD-II criteria for diagnosing 1.1 migraine without aura A. At least 5 attacks fulfilling criteria B through D B. Headache attacks lasting 4 to 72 hours (untreated or unsuccessfully treated) C. Headache has at least 2 of the following characteristics: 1. Unilateral location 2. Pulsating quality 3. Moderate to severe pain 4. Aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs) D. During headache at least 1 of the following: 1. Nausea and/or vomiting 2. Photophobia and phonophobia E. Not attributed to another disorder Reproduced with permission of the International Headache Society. 3 without headache occurs in individuals who also experience migraine headaches. It can also occur in those who have experienced migraine headaches earlier in life and, with time, the migraine headache itself gradually disappears, but episodes of the aura persist. Less commonly, and primarily in males, an individual will experience typical aura without headache and no other migraine forms. Typical aura without headache can sometimes mimic other more serious conditions, such as transient ischemic attacks. Typical aura without headache is a diagnosis of exclusion, and is of increasing concern if the individual has no history of migraine or if the onset occurs over age Likewise, increased caution should be used when diagnosing typical aura with nonmigraine headache, because it lacks the distinctive characteristic of the migraine headache, making the presentation more suspicious. 3 In familial hemiplegic migraine (1.2.4) and sporadic hemiplegic migraine (1.2.5), the patient experiences a migraine headache satisfying criteria B through E, motor aura, and at least 1 other type of aura. 3 These 2 migraines manifest themselves similarly, but familial hemiplegic migraine runs in families; 3 genes have been identified. 9 In fact, a first- or second-degree relative is necessary for diagnosis. In the absence of a relative with the condition, the diagnosis of sporadic hemiplegic migraine requires neuroimaging and a lumbar puncture to rule out other causes. 3 Basilar-type migraine (1.2.6) is the sixth subtype of migraine with aura, although new research suggests that it will ultimately be reclassified. This migraine subtype features visual aura in addition to 2 or more basilar-type aura symptoms. 23 The basilar-type symptoms, often occurring in succession, may include vertigo, dysarthria, tinnitus, diplopia, bilateral paresthesia, decreased level of consciousness, hypacusia, and ataxia. 3 Diplopia occurs in 45% of patients. 23 Sensory or speech aura may also occur. Headache fulfilling criteria B through E is present in patients with this type of migraine, 3 although some attacks may lack the headache. In 95% of cases, basilar-type migraine co-occurs

4 Hilla Abel Review Article 141 with typical aura with migraine headache. 23 Basilar-type migraine requires diagnostic caution as well, with particular consideration of transient ischemic attacks. 3,23 It is unknown whether basilar-type migraine originates from the basilar artery or from both hemispheres of the brain. It is mostly diagnosed in young adults. 3 The next set of migraine subtypes is childhood periodic syndromes that are commonly precursors to migraine (1.3). Studies have found that these distinctly pediatric conditions are associated with migraine. These syndromes are all diagnoses of exclusion because other conditions can present similarly. Cyclical vomiting (1.3.1) entails recurrent episodes of intense nausea and vomiting lasting 1 hour to 5 days. These attacks tend to occur regularly every few weeks, usually early in the morning. Abdominal migraine (1.3.2) primarily involves episodes of midline or periumbilical abdominal pain that can last hours or even several days. Associated symptoms may include nausea, vomiting, anorexia, and pallor. Benign paroxysmal vertigo of childhood (1.3.3) is characterized by spontaneous episodes of vertigo, manifested by unsteadiness or ataxia. Associated symptoms may include nystagmus, vomiting, nausea, and headache. 3,24 Patients with childhood periodic syndromes, though unlikely to present to an optometrist, must be referred to rule out gastrointestinal, traumatic, cerebrovascular, metabolic, and neurologic disorders including epilepsy. 24 Besides the distinctly pediatric syndromes, some children experience the same migraine types as adults, although some differences in presentation may exist. For example, untreated headache may be of shorter duration, ranging from 1 to 72 hours in children compared with 4 to 72 hours in an adult. Children are also more likely than adults to have a bilateral headache, with a change in laterality occurring in late adolescence. Occipital headache in children, however, is rare and may indicate a structural lesion; these cases must be investigated carefully. 3,25 It is important for the clinician to be cognizant of the occurrence of headache in children and familiar with its presentation. One study of headache prevalence in a pediatric ophthalmology practice found that 8.9% of patients had a chief complaint of headache; of those, 79.5% suffered from migraine. 26 Retinal migraine (1.4) stands apart from other migraines with aura because the aura of retinal migraine is distinctly monocular. The monocular visual disturbance precedes or joins a migraine headache fulfilling criteria B through E. It is imperative for the clinician to determine whether the patient is correctly reporting true monocular visual disturbances. Patients with a binocular hemianopic disturbance often erroneously attribute the visual disturbance to one eye. The patient must specifically report that each eye was covered during the event and that it was determined that the visual disturbance was in one eye only. 3 The topic of retinal migraine and its definition have sparked controversies in the literature. Some investigators contend that retinal migraine is an exceedingly rare phenomenon, 27,28 whereas others believe that it is underrecognized. 29 A debate exists on whether the visual disturbances must be fully reversible, as stated in the ICHD-II guidelines, or whether retinal migraine can cause permanent vision loss. Although some reports document half of patients with retinal migraine experiencing permanent vision loss, 29,30 others dispute that these cases of permanent vision loss truly represent migraine. 31 Yet another aspect of the debate is an existential one: Is it correct to categorize these monocular visual disturbances as migraine? Those who argue against its inclusion in the migraine classification suggest that the underlying cause is a probable vasospasm ( presumed retinal vasospasm ) and that it should be termed as such. 27 Although the debate will likely continue, and future ICHD guidelines will be updated, there is one point that is not contested: monocular visual disturbances with headache must be evaluated carefully, and other etiologies must always be ruled out. 3,29,32 Chronic migraine (1.5.1) is a new addition to ICHD in response to growing awareness regarding its significance. Chronic migraine usually begins as migraine without aura that then increases in frequency, such that the headache occurs more than 15 days per month for at least 3 months. 3 Given that migraine is progressive in some individuals, and that an already debilitating condition can become more frequent, treatment is all the more crucial. Timely treatment of migraine has a multifaceted role in alleviating pain and associated symptoms of a given attack in addition to potentially preventing the progression of migraine into chronic migraine. 10 Other migraine subtypes fall under complications of migraine (1.5) and probable migraine (1.6). Complications of migraine include migraine subtypes in which headache pain or aura is unusually drawn out or in which migraine is associated with an ischemic infarction of the brain or with epilepsy. These patients must be under the care of a neurologist, and proper investigation of other etiologies is necessary. Probable migraine encompasses migraine-like headaches, which do not precisely meet diagnostic criteria. 3 It should be noted that ophthalmoplegic migraine (13.7) is no longer included among migraine headaches. This very rare headache involves a paresis of one or more ocular cranial nerves, usually the third nerve. The paresis is associated with or follows a long-lasting headache up to 1 week in duration. It is suspected that ophthalmoplegic migraine represents a recurrent demyelinating neuropathy. 3 Triggers A widespread feature of migraine is for a given stimulus to initiate the attack. Common examples include eating chocolate or drinking red wine. 33 A list of migraine triggers can be found in Table 3. Although the specific mechanism for this phenomenon is still being studied, it is attributed to an abnormal cortical function, likely cortical hyperexcitability or hyperresponsivity, through which the brain is susceptible to sensory overload. 35

5 142 Optometry, Vol 80, No 3, March 2009 Table 3 Migraine triggers 34 Alcoholic beverages Caffeine and caffeine withdrawal Food Chocolate, citrus fruits, dairy products, onions, beans, nuts, fatty foods Food additives Monosodium glutamate (MSG), aspartame (NutraSweet, Equal), tyramines, sodium nitrite Environmental changes Weather changes and travel, light and other visual triggers, strong odors Lifestyle factors Insufficient or excessive sleep, fasting, head injury, smoking, physical activity, schedule changes, stress or release from stress, anger, exhilaration, emotional letdown Hormones Menopause, oral contraception, hormone replacement therapy, pregnancy Some prescription medications Head or neck pain from another cause Adapted with permission. Ó 2009 American Academy of Neurology. It is important for a migraineur to gain awareness of specific triggers to avoid them and prevent attacks. Some triggers are distinct, such as food items or medicines, and thus avoidance is ostensibly straightforward. A noteworthy example of a medication that has been reported to trigger migraine is the antiglaucoma drop Xalatan (latanoprost, Pfizer Ophthalmics). 36 Other triggers are vague, such as irregular sleep or emotional stress. In these cases, avoidance, if possible, is a continuous process that requires lifestyle modification. Cyclical and lifetime fluctuations in hormones are common migraine triggers that warrant special attention because of their ubiquitous effects on migraine in women. Changes in hormonal status (menstruation, pregnancy, menopause) in addition to extrinsic sources of hormones (oral contraception, hormone replacement therapy) influence migraine frequency and severity. 37 Increasing levels of plasma estrogen are correlated with increasing migraine frequency at puberty. During the menstrual cycle, it is the drop in estrogen associated with menses that causes an increase in migraine attacks, 37 particularly in migraine without aura. One study has found 28% of all migraine without aura in women occurs within 4 perimenstrual days: 2 days before the onset of menses and the first 2 days of menses. Although migraine pain may be somewhat worse perimenstrually than at other times of the month, differences in headache features are minimal. 38 Women taking estrogencontaining oral contraceptives are more likely to experience migraine than women who do not. 39 There are general trends in migraine frequency throughout different life stages. For the majority of pregnant women with pre-existing migraine with aura and migraine without aura, there is an improvement in migraine frequency, particularly during the second and third trimesters, although in a small number of cases, women experience their first migraine during pregnancy. 40 Nursing seems to be a protective factor against the postpartum recurrence of migraine. 41 The effect of menopause on migraine is variable. In general, migraines worsen around the time of menopause but improve afterward when plasma estrogens decrease. 37 Hormone replacement therapy shows wide variability in migraine changes as well, with some women improving, some worsening, and some with no change. 42 Migraine triggers may be visual in nature, such as fluorescent lighting or stripes on roads. Visual triggers have been categorized into 4 types: glare, flicker, pattern, and color. Migraineurs are more likely to be disturbed by such stimuli more than nonmigraineurs, even between attacks. 43 Patients whose migraines are triggered by glare may benefit from sunglasses between attacks. Patients who experience photophobia with their migraines will also benefit from sunglasses during the attack if they are unable to rest in a dimly lit room. 44 Pattern glare is a visual migraine trigger that has been well investigated. It is a black and white striped pattern, approximately 3 cycles per degree, in which migraineurs are more likely to see distortions and illusions than are nonmigraineurs. 45,46 The implication of pattern glare is that printed text can mimic it, 47,48 and thus reading is bothersome to some migraineurs even between attacks. Treatment for patients who are bothered by pattern glare is discussed below. For decades, the role of refractive error and binocular anomalies in migraine has been debated, 49 but new wellcontrolled studies have attempted to solve this mystery. A study on refractive error shows that uncorrected astigmatism and high degrees of astigmatism, and possibly anisometropia, are associated with migraines. 50 Binocular vision anomalies (heterophoria, reduced stereopsis) in migraineurs have been found to be subtle. 51 Neither of these studies established causation between refractive error or binocular anomalies and migraine. 50,51 Clinical features Blau 52 has described 5 stages of a migraine attack. They are (1) prodrome, (2) aura, (3) headache, (4) resolution, and (5) postdrome. Each individual migraineur may only experience, or be aware of, some of the stages during a particular migraine episode. 52 Although there is no mechanistic explanation for 5 distinct stages at this time, Blau s stages remain a useful construct for understanding the migraine experience. Some migraineurs will be able to predict an impending migraine via the prodrome, recently renamed premonitory symptoms to emphasize it as a separate entity from the aura stage. The premonitory symptoms precede the migraine attack by hours or days 3 and are experienced by nearly one third of migraineurs. 53 Common symptoms

6 Hilla Abel Review Article 143 include fatigue, malaise, mood changes, gastrointestinal symptoms, anxiety, phonophobia, irritability, unhappiness, and yawning. 53,54 The premonitory symptoms, and their recognition by the patient, represent an opportunity to use certain medications earlier on when they are more likely to halt the headache process. 53 Aura may precede the headache, or it may accompany the headache. It can also occur without the headache, in the form of typical aura without headache. Aura develops over 5 to 20 minutes, and usually lasts less than an hour. Aura that lasts beyond this duration is concerning. 3 Aura is experienced by 31% of migraineurs during some or all of their migraines. 19 Except for the controversial monocular aura of retinal migraine, visual aura is a binocular phenomenon. It is important to be familiar with the variety of visual auras; a recent survey in an optometric practice has found that 54% of migraine patients experience visual aura. 5 The most classically described form of visual aura has several namesdfortification spectra, teichopsia, and scintillating scotomadbased on the early Italian fortifications that were built in a zigzag configuration, as well as for their shimmering, sparkly quality. 49,51 They consist of zigzag lines in a semi-circular shape that spread or move in the visual field in what is known as a march, and may leave a scotoma in their wake. 3 Pictorial depictions of fortification spectra can be seen in Schott s review of scientists illustrations of their own visual aura. 55 While fortification spectra are typical, other descriptions of visual aura exist. In general, visual auras are grouped into 3 types: positive visual phenomena, negative visual phenomena, and disturbances of visual perception. Positive visual phenomena are photopsias that are not normally present, such as zigzag fortification spectra, white dots, colored spots, and curved or straight lines. Negative visual phenomena appear as a scotoma, such as a black dot or hemianopsia. Disturbances in visual perception include unusual qualities of the vision, such as blurred vision, tunnel vision, wavy vision, mosaic vision, and others. Some individuals experience more than one type of visual aura. Visual auras typically start in the periphery and march across the vision. Fortification spectra, however, tend to begin at fixation and spread outwards. 56 Although visual aura is the most common type of aura and the best known to optometrists, there are 3 other types of aura: sensory aura, speech aura, and nonspeech motor aura. Sensory auras include numbness or the sensation of pins and needles along one side of the body. The feeling may spread along the body, analogous to the march of a visual aura within the visual field. 3 Speech disturbances can range from mild language dysfunction to an inability to communicate. 57 Other motor aura refers to some degree of unilateral weakness in the body. Motor aura is rare and atypical because it is limited to hemiplegic migraines. When sensory aura, speech, or motor aura do occur, however, it tends to be accompanied by visual aura. Multiple aura types in one attack often occur in succession. 3 Migraine headaches have been traditionally regarded as unilateral headaches; in fact, the word migraine originates from the Greek word hemikrania, meaning half the head. 58 Although 59% to 67% of migraineurs experience unilateral headache, bilateral migraines are possible. 1,59 The location typically is orbital, temporal, or frontal, with some occurrences of pain in the occiput, neck, diffusely throughout the head, or at the top of the head. Pain does not usually occur in isolated areas, but rather in multiple locations in the head in a given attack. 59 Eighty-five percent experience a throbbing or pulsating quality of the headache. The associated symptoms of nausea, vomiting, photophobia, and phonophobia affect 73%, 29%, 80%, and 76% of migraineurs, respectively. 1 Sixty-three to 79% of migraineurs experience the perception of pain in response to normal activities, such as shaving, showering, or wearing jewelry, known as allodynia. The onset of allodynia is after the onset of head pain. 16,60 Ultimately, the headache resolves gradually and is usually aided by medication, sleep, or both. 52 Untreated headaches last between 4 and 72 hours. 3 Even once the headache has resolved, symptoms may persist. This is known as the postdrome, nonfocal neurologic symptoms analogous to the premonitory symptoms. Patients typically report feeling washed out, drained, or hung over. Other common symptoms include weakness, tiredness, drowsiness, difficulty concentrating, head pain, gastrointestinal symptoms, and mood changes. 52,54,61 Sixtyeight percent of migraineurs report a postdrome, though not necessarily with every migraine attack. 61 Optometric examination The eye examination investigates migraine from several angles, exploring refractive, binocular, neurologic, and ocular-pathological factors that may play a role in aura or headache. Optometric testing for headache patients is summarized in Table 4. Visual aura needs to be differentiated from symptoms manifesting from ocular pathology via a dilated fundus examination. This is imperative for patients who can pinpoint monocular symptoms. Phosphenes may originate from vitreo-retinal traction, and scotomas may be caused by various retinopathies. Although some studies maintain that certain fundoscopic findings are consistent with migraine, 30,62 this should not be assumed. Neuro-ophthalmic testing is of particular importance to alert the clinician to potentially serious neurologic abnormalities. Care should be taken to examine the optic nerves for disc edema or pallor. Automated visual fields are indicated when a lesion of the visual pathway is suspected; it is prudent to run a visual field with a worrisome history or with other abnormal neurologic findings. Pupils, extraocular motility, cranial nerve testing, and color vision are useful in the assessment of the patient s neuro-ophthalmic state. However, some abnormalities in these tests may be consistent with migraine. Anisocoria occurs in migraineurs more frequently than nonmigraineurs Benign episodic unilateral

7 144 Optometry, Vol 80, No 3, March 2009 Table 4 Optometric testing for patients with headache Visual acuity Refraction Binocular vision valuation Pupil assessment Cranial nerve testing including extraocular motility Color vision testing Visual field examination Slit lamp examination Tonometry Dilated fundus examination Blood pressure evaluation mydriasis is a specific form of anisocoria that can rarely occur in migraineurs. 66 Horner s syndrome is occasionally seen in conjunction with migraine, although ipsilateral headache and Horner s syndrome may also be indicative of carotid artery dissection, cluster headache, and paroxysmal hemicrania. 63 Diplopia may occur with basilar-type migraine. 3 Pupillary abnormalities in conjunction with periocular pain during a migraine attack can alert the clinician to possible narrow-angle glaucoma. Cases of subacute narrowangle glaucoma mimicking migraine have been well documented. 64,67-69 These patients generally are older and have shorter duration of headache than is typical for migraine. An analysis of misdiagnoses by primary care physicians and neurologists has shown that the majority (64%) of these cases do not meet strict ICHD criteria, thus highlighting the importance of proper history taking and attention to atypical presentations. 68 Complaints of pain behind or around the eye should prompt an investigation to rule out ocular sources of pain, including glaucoma and inflammation. Normal-tension glaucoma has been associated with migraine as well, presumably linked by a vascular pathogenesis. 70 A large proportion of patients with normal-tension glaucoma have been found to have a history of migraine, and vice-versa, significant numbers of migraineurs have been shown to have glaucomalike visual field defects. 74 In patients who have normal-tension glaucoma, migraineurs are more likely to show visual field progression than nonmigraineurs. 75 For these reasons, some clinicians may wish to screen all migraineurs for normaltension glaucoma with automated visual field testing. However, false-positives may occur because some cases of glaucomalike visual field defects in migraineurs may be inherent to migraine itself rather than resulting from a glaucomatous process. 76,77 In addition, it should be noted that the association between migraine and normal-tension glaucoma has been generally but not universally accepted. 78,79 Nonglaucomatous visual field defects have also been recorded with migraine. Although controversial, retinal migraines ultimately cause permanent monocular visual field defects in some patients. A review of retinal migraine cases in the literature has found that nearly half (46%) eventually experienced permanent monocular vision loss. For this reason, some practitioners treat retinal migraine prophylactically. 30,80 Rarely, binocular visual field defects are attributed to migraine once other etiologies have been comprehensively ruled out. 81 Diagnosis In addition to the examination, a proper headache history is crucial for migraine diagnosis. Although every history is tailored to the individual, questions may include medical history and medications, social history, family history (including migraine), a description of the headache (frequency, onset, duration, location, laterality, severity, progression, throbbing or constant pain, aggravating and relieving factors), suspected triggers (including visual triggers), warning symptoms of an attack (premonitory symptoms), the presence of aura and its characteristics (type, duration, temporal relation to head pain), and associated symptoms (nausea, vomiting, photophobia, phonophobia and others). It is reassuring when patients strictly meet diagnostic criteria, when there is a family history of migraine and when headache attacks are separated by headache-free periods. The history assists the clinician in differentiating migraine from other primary headaches (tension-type headache, cluster headache, and other miscellaneous primary headaches) and secondary headaches attributed to an underlying pathology. Tension-type headaches are the most common primary headache; they differ from migraine in their typical presentation by being less severe, nonpuslating, bilateral, lacking nausea or vomiting, and not aggravated by routine physical activity. Cluster headaches are severe and unilateral. Unlike migraine, they are more common in men, tend to occur in series separated by periods of remission, and provoke the individual to pace rather than rest. Secondary headaches result from a range of conditions, from those that affect quality of life (e.g., temporomandibular joint disorder) to those that are immediately threatening to life. 3 Although migraine is largely a benign condition, sinister mimickers have been reported. While conducting the history, the clinician should be alert to red flags that raise suspicion of a serious nonmigraine etiology, summarized in Table 5. Certain red flags warrant emergency action. For example, a severe sudden-onset headache ( thunderclap headache) suggests subarachnoid hemorrhage, and neck stiffness may indicate meningitis. In general, red flags are indication for neuroimaging or other medical or neurologic testing to investigate the possibility of other etiologies. In some cases, subtle red flags represent early indicators of serious pathology. Patients with visual aura should be questioned regarding their symptoms to ensure that they are consistent with migraine diagnostic criteria. Visual symptoms mimicking migrainous aura can be found in other conditions, some of which may present with headache, including arteriovenous malformation, 88,89 carotid artery dissection, 90 epilepsy, 91 subarachnoid hemorrhage, 92 and occipital lobe tumor. 93 For this reason, typical aura without headache is a

8 Hilla Abel Review Article 145 Table 5 Red flags that raise suspicion of a serious nonmigraine etiology 3,25,55,82-88 Headache features First or worst headache, sudden onset severe headache ( thunderclap headache ), acute onset with occipitonucchal location, increasing severity or frequency, change in clinical features, headache always on the same side ( side-locked headaches ), headaches not responding to treatment, post-traumatic headache, headache that awakens the patient from sleep, onset with exertion or intercourse, headache aggravated by exertion or valsalvalike maneuver, occipital location in children Aura features Aura that is prolonged or very short Aura that follows the headache Aura with predominantly negative features (hemianopsia) Patient demographics New headaches in patients who have cancer or are HIVpositive New headaches after age 50 New aura after age 40 Accompanying signs or symptoms Focal neurologic signs or symptoms (basilar symptoms, sensory abnormalities, hemiparesis, etc.), other than usual visual aura Change in personality or mental status Loss of consciousness Poorly pulsative temporal arteries, jaw claudication, scalp tenderness Signs of systemic illness Fever, neck stiffness, neck pain, back pain, rash, weight loss, seizures, lymphadenopathy, recurrent nasal drainage, chronic cough, lack of coordination Examination findings Signs of subacute angle-closure glaucoma, disc swelling, cranial nerve palsy, visual field findings suggestive of neurologic disease Ocular bruit diagnosis of exclusion. 22 The monocular aura of retinal migraine is a diagnosis of exclusion as well, in which other causes of transient monocular blindness must be ruled out, including embolism, ischemic diseases of the eye and brain, orbital or intracranial lesions, vascular disease, and hypercoagulable disease. 3,32 Transient ischemic attack (TIA) is a notable differential diagnosis that can present with auralike symptoms. TIA should be considered in new cases of aura, with increased concern in patients over the age of 40 and those with stroke risk factors. History may provide some clues in differentiating TIA from migraineous aura. The visual symptoms of TIA tend to have a briefer onset and a shorter duration of visual symptoms than does migraineous aura; they may also be described as having a curtain pulled over the eye, unlike migraineous aura. 29 The march or build-up of migraineous aura is encouraging of a migraine diagnosis, as are fortification spectra, but neither is exclusive to migraine. 5,94 A complicating aspect of the differential diagnosis of TIA is that migraine with aura has been shown to be associated with stroke, particularly in young women. 95 Patients who are referred to an internist, neurologist, or emergency room will have an examination in conjunction with any necessary diagnostic testing. Neuroimaging by magnetic resonance imaging or computed tomography is done commonly for suspicious presentations to investigate for a variety of intracranial lesions. Blood tests are appropriate with suspicion of inflammatory, infectious, or metabolic disease or for hormonal and blood abnormalities. They can also serve as a baseline to monitor drug side effects. Other specialized testing may be considered, including lumbar puncture, electroencephalography, cerebral arteriography, magnetic resonance angiography, spiral computed tomography angiography, ultrasound of the carotid artery or heart, transcranial Doppler, and echocardiogram. 85,96 Treatment Strategies for migraine management consist of general measures and pharmacologic treatment. Although pharmacologic treatment of migraine is the responsibility of the managing internist or neurologist, optometrists can actively participate in certain nonpharmacologic management strategies. Patients who are not already under the care of a physician should be encouraged to seek treatment, as proper treatment increases the quality of life for the patient. Many patients are not aware that effective migraine treatments exist; others may be abusing over-the-counter medications. Nonpharmacologic approaches to migraine management may be used alone or in combination with pharmacologic therapy. Some patients may wish to avoid taking medications, be intolerant or unresponsive to pharmacologic therapy, or have contraindications to it. Regulating stress levels and maintaining regular routines of sleep, meals, and exercise can help prevent migraines. Specific techniques have been determined to be effective in research trials: relaxation training, biofeedback training, and cognitivebehavioral therapy. 86 Patients who are interested in these techniques can be referred to a headache center or to a headache specialist. All migraineurs should also be counseled on trigger avoidance. A headache journal is a helpful tool to gain awareness of one s triggers. The patient keeps track of the onset and duration of each headache, the suspected triggers, the severity of the headache, associated symptoms, what the headache prevents the patient from doing, and the medications taken. 97 The headache journal is also helpful for the treating physician to confirm the diagnosis of migraine, to monitor the frequency of migraines, and to evaluate the effectiveness of the medications. It is appropriate for an optometrist to recommend to a patient to start keeping a headache journal. In cases of nonurgent referrals to

9 146 Optometry, Vol 80, No 3, March 2009 internists or neurologists, patients should also be educated to begin a headache journal before the physician visit. Patients with visual triggers may benefit from optical correction and tint. Although there is no strong association between migraine and refractive error or binocular anomalies, 50,51 it is prudent to manage these conditions when they are deemed significant. Patients who are photophobic during attacks or between attacks benefit from sunglasses. Colored lenses have been shown to alleviate discomfort from pattern glare, which can manifest as discomfort while reading printed text. 98 Although some have advocated rose tint 99 and traditional methods have favored light blue tint, 100 the bulk of recent research in this area has focused on the benefits of precision tinted lenses. The precise tint is selected by the patient for maximum visual comfort and clarity using an instrument developed for this purpose, the Intuitive Colorimeter (Cerium Visual Technologies, Kent, England), based on incremental adjustments of hue and saturation. In addition to greater comfort while reading, there is some suggestion that tint may decrease the frequency of headache. 98 As an alternative to tint, colored overlays that are placed directly on top of the reading material have shown benefit in improving text clarity. 45 However, the optimal color of the overlay is not the same as the optimal lens tint. 101 Pharmacologic treatment for migraine falls into 2 main categories: symptomatic and preventive. Symptomatic treatment, also known as abortive treatment, is taken at the first sign of an attack. These medications commonly are taken orally, but nonoral routes of administration are available for patients who are vomiting or nauseated. In patients with milder headaches, analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) may be sufficient. These include aspirin, naproxen, and ibuprofen, which are also found in combination with caffeine or isometheptene. Opiates are best avoided because of adverse effects and the risk of addiction. Triptans are a popular symptomatic treatment, known for their efficacy. Examples include the oral medications Imitrex (sumatriptan, GlaxoSmithKline; Brentford, Middlesex, United Kingdom) and Maxalt (rizatriptan, Merck & Co., Inc.; Whitehouse Station, New Jersey). Although triptans can be quite pricey, ergot derivativesdergotamine and dihydroergotaminedare lower in cost but associated with a higher rate of adverse effects. Both triptans and ergot derivatives, however, may be contraindicated in certain migraine types because of their vasoconstrictive properties. Use of symptomatic treatments should be monitored and limited because frequent use of these medications can cause medication-overuse headaches, also known as rebound headaches. Besides the treatment of headache pain, antiemetics are used as adjunct therapy to treat nausea and vomiting. 86,102 Intravenous or oral hydration with a glucose-containing solution is necessary in cases of severe vomiting, for example, in children with cyclical vomiting. 24 Preventive treatment is a prophylactic approach, where medication is taken daily to decrease the frequency and severity of migraine headaches. This strategy is appropriate in patients with significantly frequent or debilitating migraines or when symptomatic treatment is ineffective. 102 Preventive treatment may also avert the transformation to chronic migraine in cases in which migraines are increasing in frequency. 10 A variety of preventive medications are used, including beta-blockers, antiepileptics, antidepressants, calcium channel blockers, NSAIDs, serotonin antagonists, and certain alternative treatments, 86 which include butterbur (Petasites hybridus), magnesium, feverfew (Tanacetum parthenium), riboflavin, and coenzyme Q10. These alternative treatments have grade B quality of evidence, meaning that there is limited or inconsistent evidence of their effectiveness in trials. Because these agents are classified as dietary supplements, it should be considered that they are not as strictly regulated by the U.S. Food and Drug Administration. 103 In addition, recent studies tout the benefits of botulinum toxin (Botox, Allergan) injection in reducing migraine headache pain. 104 It is important to note that topiramate, a sulfa-derived antiepileptic drug used for migraine prophylaxis, has been reported to cause myopia and acute, bilateral, angle-closure glaucoma. Myopia can also occur without concurrent glaucoma. 105 Cases have been reported in both children and adults The mechanism is a ciliochoroidal effusion with an anterior displacement of the lens-iris diaphragm and anterior chamber shallowing. 109 The myopia is reversible with the cessation of topiramate; angle-closure glaucoma must be treated as an emergency. Patients who take topiramate should be warned of potential side effects. Conclusion Optometrists can increase the quality of life for their migraine patients in a variety of ways. Some solutions for migraineurs fall into a uniquely optometric arena through the correction of ametropia and binocular abnormalities, sunglasses, and colored tints or overlays for increasing reading comfort in susceptible individuals. Glaucoma evaluation in migraineurs, too, is crucial for preserving lifelong vision. Patients must be educated about migraines and the benefits of proper diagnosis and treatment. Optometrists must be mindful of ocular and nonocular differential diagnoses. As with all headache patients, suspicious presentations should raise alarm, and these patients should be referred for further testing in an appropriate time course. References 1. Lipton RB, Stewart WF, Diamond S, et al. Prevalence and burden of migraine in the United States: data from the American migraine study II. Headache 2001;41: Silberstein SD. Migraine pathophysiology and its clinical implications. Cephalalgia 2004;24(Suppl 2): Headache Classification Subcommittee of the International Headache Society. The international classification of headache disorders. 2nd edition. Cephalalgia 2004;24(Suppl 1):9-160.