Are we underdiagnosing migraines? By Cynthia E. Armand, MD; Alina Masters-Israilov, MD; and Richard B. Lipton, MD
Migraine mimics are primary or listed in the Box.1 Although the diagnostic criteria are explicit, secondary headache disorders many migraine features are also found in other primary head- with features in common with ache disorders. For example, unilateral pain characterizes both migraine that may lead to errone- migraine and the trigeminal autonomic cephalalgias (TACs). ous, false-positive diagnosis of In addition, ICHD-3 diagnoses require that the headache migraine. For people seeking care disorder is not better accounted for by another condition. for severe recurrent headaches, migraine is the This seemingly simple statement means that meeting the most likely diagnosis, justifying a high index of symptom criteria for migraine is not sufficient to establish a suspicion for migraine. This can lead to errors of diagnosis. The clinician has to also ensure that there is no bet- overdiagnosis and missed opportunities to treat ter explanation for the patient’s symptoms. Diagnostic errors the disorder that is truly present. The possibility often lead to therapeutic delay. of migraine mimics should be considered: • at the time of the initial consultation Trigeminal Autonomic Cephalalgias • in anyone diagnosed with migraine who does not have the The TACs comprise a group of primary headache disorders expected response to treatment that have the hallmark of unilateral headache with ipsilateral • in anyone diagnosed with migraine whose headache fea- cranial autonomic symptoms, including tures change over time. • cluster headache (CH) Another factor is that more than a single diagnosis may be • paroxysmal hemicranias (PH) present (ie, migraine and another condition). Our suggested • hemicrania continua (HC) and diagnostic approach is summarized in the Figure. • short-lasting unilateral neuralgiform headache attacks Individuals presenting with recurrent moderate-to-severe with or without conjunctival injection (SUNCT/SUNA). headaches as a prominent symptom require meticulous The TACs are distinguished from one another by attack evaluation. That evaluation usually begins with identifica- frequency, attack duration, and patterns of response to treat- tion or exclusion of secondary headache disorders, defined as ment. All can be confused with migraine because unilateral headache disorders attributable to another disease. A careful pain is common to all, and patterns of associated symptoms history is followed by general medical and neurologic examina- and treatment response for the TACs and migraine overlap. tions to search for red flags, ie, clinical features that suggest the The defining cranial autonomic features of TACs also occur possibility of a secondary headache disorder. When red flags commonly in migraine; likewise, the associated symptoms are present, a targeted diagnostic evaluation is undertaken to support or exclude suspected secondary headache disorders. Box. Diagnostic Criteria for Migraine Herein, we first consider the diagnosis of migraine mimics at the time of the initial consultation, starting with primary • Recurrent headaches that last from 4 to 72 hours headache disorders and then moving on to secondary head- • At least 2 of the following cardinal pain features ache disorders. Next, we consider the possibility of migraine • Unilateral location mimics later in the course of treatment when people’s head- • Pulsating quality aches do not respond to treatment as expected or when • Moderate-to-severe intensity headache patterns change. Finally, we consider the possibil- • Aggravation from physical activity ity that more than 1 type of headache is present. • Have a pattern of associated symptoms of • Nausea Primary Headache Disorders • Photophobia Core features of migraine according to the International • Phonophobia Classification of Headache Disorders, 3rd edition (ICHD-3) are
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no
Figure. Migraine mimics diagnostic algorithm. A key element of the differential diagnosis, after ruling out red flags and atypical features that indicate secondary headache, is distinguishing frequency and duration of headaches such that they can be grouped (left to right) as less frequent long-lasting, less frequent short-lasting, frequent long-lasting, and frequent short-lasting headaches. Abbreviations: SUNA, short-lasting unilateral neuralgiform headache attack; SUNCT, short-lasting unilateral neuralgiform headache with conjunctival injection. of migraine (ie, nausea, photophobia, and phonophobia) are Remarkable for the continuous headache with exacerba- common in the TACs.2 tions of pain, HC can be confused with migraine, particularly Characterized by unilateral severe pain, CH attacks last if the history focuses exclusively on the painful exacerbations 15 to 180 minutes with autonomic features and sometimes a that are a hallmark of HC. Individuals with HC often have sense of restlessness.1 Associated symptoms characteristic of migrainous features.5 In a case series it was noted that 74% migraine are often seen in CH attacks.3,4 With these features, of persons with HC had associated symptoms of migraine.6 and increased occurrence of attacks, CH can be misdiagnosed Another study suggests 52% of people correctly diagnosed as chronic migraine. Features that differentiate CH from with HC were initially diagnosed with migraine.7 Pain-free migraine are shorter attack duration, circa-annual and circadi- intervals between exacerbations favor a diagnosis of migraine, an patterns, and restlessness that can occur during a CH attack. whereas absence of pain-free intervals favors HC. If pain is
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continuous, and the headache is side locked with cranial auto- Secondary Headache Disorders nomic features, HC should be considered strongly. Focusing Some secondary headache disorders that can mimic only on exacerbations and not baseline level of pain can lead migraine can potentially be life threatening. Certain red flags to misdiagnosis of migraine or CH, depending on duration of (The Red Flag List) can raise the suspicion for secondary causes, exacerbations. Even when background continuous headache is including rapid onset of headache, association of headache taken into account, there is still danger for misdiagnosing HC with focal neurologic signs, and initial headache onset in a per- as chronic migraine. The hallmark of a definitive diagnosis of son over age 50.11 It is also important to tease out any unique HC is absolute response to indomethacin, which leads to com- features of a newly presenting headache from those a person plete pain freedom and no pain recurrence once the appropri- with a chronic headache disorder has previously experienced. ate dose is reached. Migraine may respond to indomethacin, but rarely completely and may also respond incompletely to Vascular Secondary Headaches other nonsteroidal anti-inflammatories. With the exception of Arterial Dissection. Headache associated with cervical or ver- persistent background headache, PH shares the same features tebral arterial dissection may resemble migraine. These head- of HC. Individuals with PH have distinct pain-free periods. aches may be unilateral and are sometimes associated with With highest frequency and shortest duration of attacks, nausea and vomiting, as well as visual disturbances reminiscent SUNCT/SUNA attacks are moderate-to-severe single-to-mul- of aura and photophobia.12,13 The severity of pain and duration tiple stabs of pain lasting from 1 to 600 seconds.1 Compared of headache associated with arterial dissection can also mimic with other TACs, the differential diagnosis for SUNCT/SUNA migraine, although onset of pain may be more rapid in dis- more often includes short-lasting neuralgiform facial pain syn- section.1 Signs secondary to cerebral ischemia or sympathetic dromes (eg, trigeminal neuralgia) rather than migraine, simply compromise can help differentiate migraine from arterial because migraine duration is usually 4 to 72 hours. dissection; however, these can often present at a later time fol- lowing headache and potentially delay correct diagnosis. New Daily Persistent Headache Giant Cell Arteritis. The headache associated with giant cell New daily persistent headache (NDPH) is characterized as a arteritis (GCA) can also have migrainous features and may be persistent headache, clearly remembered from onset, possibly associated with temporary visual loss called amaurosis fugax with features of tension-type headache, migraine, or both that that can be confused with visual aura. Among other features is present for at least 3 months. This implies that any head- of GCA, the presence of systemic symptoms such as weight ache phenotype considered primary that has persisted for loss, fevers and/or malaise and onset of headache after age 60 3 months should include NDPH on the differential diagnosis. should prompt further workup for this condition.14 The dilemma diagnostically is that both tension-type head- Stroke and Other Vasculopathies. Stroke, intracranial hem- ache and migraine have chronic forms that can be intractable, orrhage, venous sinus thrombosis, reversible cerebral vaso- making it easy to misdiagnose NDPH for chronic migraine and constriction syndrome (RCVS), and genetic vasculopathies vice versa. This diagnostic challenge has caused many to inves- may have associated headache, some of which also have tigate therapeutic methods that treat all of these headache migrainous features.1 Focal neurologic symptoms and signs disorders, although this was once considered an impossible and changes in level of alertness warrant further exploration goal. OnabotulinumtoxinA, which is approved for treatment of etiology, although these features are also sometimes associ- of chronic migraine by the Food and Drug Administration ated with migraine, causing false-negative migraine diagnoses. (FDA), also provides improvement in headache frequency Thunderclap Headache. Whenever there is suspicion for vas- and severity for persons with NDPH over a 12-month period.8 cular secondary headaches, migraine should be a diagnosis of Notoriously very difficult to treat,9 strategies for NDPH often exclusion. This is particularly so for a headache with thunder- focus on clarifying the headache phenotype for the best clap onset, which warrants rigorous evaluation for a secondary chance of achieving a goal toward headache freedom. cause. Any headache with an onset reaching peak intensity in less than 1 minute is, by definition, a headache of thunderclap Hypnic Headache onset that can allude to a subarachnoid hemorrhage, hemor- The ICHD-3 describes hypnic headache as a frequently rhagic stroke, RCVS, or even pituitary apoplexy. After these life- occurring headache attack without cranial autonomic symp- threatening conditions have been ruled out, returning to the toms. With attacks of up to 4 hours that develop during consideration of migraine should also include the possibility of sleep and often wake a person from sleep, hypnic headache primary thunderclap headache—then called crash migraine. is easily misdiagnosed as migraine. In a case series of 23 peo- Transient Ischemic Attacks. Often confused for migraine ple diagnosed with hypnic headache, about 70% also had aura and vice versa, transient ischemic attacks (TIAs) have a history of migraine, shedding light on the fact that these acute focal neurologic onset. A study found certain sociode- disorders may coexist.10 mographic features including age, male sex, history of vascular
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THE RED FLAG LIST Look for a diagnosis other than a headache disorder when these findings are present.
Rapid onset of symptoms Age at onset > 50 Consider arterial dissection, TIA, SAH, sinus venous Consider giant cell arteritis, intracranial tumors thrombosis, hypoglycemia, or seizure. Order CT (metastasis), or hypertension. Order plasma ESR angiography, brain MRI with and without contrast, and CRP, and brain MRI with and without contrast. fingerstick glucose level, lumbar puncture, and EEG. Check blood pressure.
Thunderclap headache Worsening with positional changes or Reaching maximum pain intensity in less than Valsalva maneuver 1 minute may allude to SAH, hemorrhagic stroke, Consider IIH, sinus venous thrombosis, intracranial RCVS, or pituitary apoplexy. Order urgent head and mass, or CSF leak. Order ophthalmologic evalu- neck CT and CT angiography (CTA). ation, brain and spine MRI with and without con- trast, lumbar puncture, and CT myelography. Presence of neurologic symptoms and signs Consider arterial dissection, stroke, giant cell arte- New or worsening headache in patient with ritis, or glaucoma. Order head and neck and brain history of migraine MRI and MR angiography (MRA), plasma ESR and Consider medication overuse, hypertension, intra- CRP, and ophthalmologic evaluation. cranial mass, or medication side effects. Consider pill counting/diary and medication taper. Check Prominent neck pain with or without fever blood pressure. Order brain MRI, standard blood Consider meningitis. Order standard blood chemis- chemistry and cell counts, and thyroid function try and cell counts. Consider lumbar puncture and testing. Review all medications. CSF analysis. Abbreviations: CRP, C-reactive protein; CSF, cerebrospinal fluid; ESR, erythrocyte sedimentation rate; IIH, idiopathic intracranial hypertension; RCVS, reversible cerebral vasoconstriction syndrome; SAH, subarachnoid hemorrhage; TIA, transient ischemic attack. risk factors (eg, hypertension or hyperlipidemia), as well as a sion (IIH) may often be confused with migraine. The demo- history of mostly motor-type symptoms and symptoms lasting graphics for people with either condition overlap significantly less than 1 hour to all be associated with TIA versus migraine and IIH and migraine may often be comorbid.17 Headaches aura. The authors felt, however, that no clinical elements were that worsen upon awakening as well as other positional sufficient to discriminate between the 2 entities.15 There is a provocations, pulsatile tinnitus, and papilledema should raise relationship between migraine and TIA independent of aura concern for IIH. Low-pressure headaches secondary to a cere- as well. A recent study16 found a higher 1-year prevalence of brospinal fluid (CSF) leak are also important to keep on the migraine without aura in people who had experienced a TIA. differential diagnosis when evaluating patients with migraine, Approximately 13% of individuals who had TIA experienced especially if they are resistant to many migraine medications. a new type of mostly migraine-like headache. Persons with These headaches tend to occur upon rising and/or later in the posterior circulation TIAs were more likely to have a migraine- day although this pattern is not always evident.18 like headache than those with anterior circulation TIA. Interestingly, migraine-like headaches appeared for the first Headache Associated With Neoplasms time in some persons with TIA. This illustrates the importance Although migraine is not the most common headache of looking for new or changed headache descriptions because phenotype in individuals with underlying brain tumors, new or worsened migraine potentially can be a warning sign migraine can be a presenting feature alongside nausea and for TIA. Recognition of this warning can hopefully help prevent vomiting, which makes arriving at the correct diagnosis chal- a possible future stroke. Conversely, inappropriate diagnosis lenging. Precipitation of headache by the Valsalva maneuver of TIA in a patient with migraine aura may result in extensive and bending over warrants investigation for neoplasms.19 In work-up and unwarranted antiplatelet therapy. a study of individuals with pituitary tumors, of those who reported headache, the features most commonly described Cerebrospinal Fluid Pressure-Related Secondary Headache included severe throbbing pain in the frontal or orbital Headache associated with idiopathic intracranial hyperten- regions and relief with rest,20 both of which are common in
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migraine as well. A potentially dangerous situation is when agnosed as migraine. Many people with migraine who use someone with a preexisting diagnosis of migraine who then abortive medications frequently experience headache with develops an underlying brain tumor (primary tumors or migrainous features; in fact, medication overuse is a risk metastasis) has neoplasm-related headache or new symptoms factor for conversion of episodic to chronic migraine. (See mistakenly attributed to migraine. A recent study found that Migraine Acute Therapies in this issue) Although MOH is participants with brain tumors also had increased risk of prior classified as a secondary headache disorder, there is debate migraine diagnosis.21 It is essential to remain vigilant whenever about this. People who experience medication overuse often an individual’s migraine course worsens without an obvious have a preexisting headache disorder such as migraine.31 explanation. Hypertension can also present as a migrainous headache or a worsening headache in a patient with history of migraine; Infectious Secondary Headaches checking blood pressure is a valuable part of headache evalua- Meningitis is frequently associated with headache but tion. Severe unilateral orbital headaches with associated visual also features other cardinal findings such as fever and nuchal changes or vision loss can indicate acute glaucoma, which rigidity.22 It is important to consider meningitis in anyone requires urgent intervention. It is, again, crucial to tease out with a history of headaches who presents with a headache new features of a unilateral headache that may suggest an that has more prominent neck pain, especially in the setting etiology other than migraine.22 The prevalence of migraine is of altered mental status. Perhaps more commonly, migraine high in people with underlying inflammatory diseases such as can masquerade as sinusitis and vice versa. Nasal symptoms systemic lupus erythematosus.32 can accompany migraine,23 and facial pain is prominent in Epilepsy also has many features similar to migraine that can migraine.24 Presence of fever and nasal discharge is helpful for lead to mutual misdiagnosis. Focal seizures and seizure aura differentiation. Sphenoid sinusitis, specifically, can often be can mimic migraine aura. Visual migraine aura can be confused misdiagnosed as migraine, because it features periorbital pain, for occipital seizures and vice versa, although symptoms are nausea, and vomiting but rarely has nasal discharge or postna- classically distinct. This is further complicated because occipital sal drip.25 Among myriad other symptoms, Lyme disease can seizures are often followed by migraine-like headache.33 often feature headache, with migraine semiology appearing Migraine is both a diagnosis of inclusion and exclusion. It is most frequently.26 Dental infections may also be a cause of a diagnosis of inclusion in that certain clinical features must be secondary headache.1 present. It is a diagnosis of exclusion in that alternative primary and secondary disorders must be excluded. Once migraine Toxic and Metabolic Causes of Headache is diagnosed, the goals of treatment are reducing headache The astute physician should always keep toxic syndromes frequency and severity, leading to an overall improvement in in his or her differential diagnosis, especially in patients quality of life. This process can take weeks to months as the presenting with acute headache. Acute carbon monoxide right medications are tried. Once headaches improve, ongoing poisoning commonly presents with frontal, throbbing, and management may be required to maintain control. If head- continuous pain that can be overlooked given the significant aches do not respond to treatment as expected, the possibility overlap with migraine.27 Many medications cause headache of alternative diagnoses should be reconsidered. as a side effect, some more notoriously than others, such as phosphodiesterase inhibitors.1 Headache Pattern Changes Hypothyroidism is associated with headaches and a large After a period of favorable response to treatment, proportion of people with headache attributed to hypothy- people with migraine may experience exacerbations. When roidism experience migrainous features, including pulsatile exacerbations occur, there are several possible explanations, quality of pain, associated nausea or vomiting, and prolonged including reduced adherence to treatment or emergence duration.28 New-onset migraine with or without other associ- of exacerbating factors such as life stress, a head injury or ated features of hypothyroidism or worsening migraine in a medication overuse. Another possibility is that a new type of patient with history of migraine should prompt thyroid stud- headache, primary or secondary, has developed in the setting ies. Hypoglycemia, particularly postprandial hypoglycemia, may of preexisting migraine. In anyone diagnosed with migraine, also cause migrainous headaches,29,30 illustrating the impor- a subtle change such as transition from episodic occurrence tance of taking a good history. It is possible that individuals to chronic occurrence or change in headache semiology can who experience a postprandial hypoglycemic headache have a be the only clue of a new primary or secondary headache. predisposition to migraine that is unmasked by hypoglycemia. Therefore, familiarity with the red flags and vigilance for the known preexisting headache disorder characteristics are Other Headache Causes paramount. If investigation of red flags does not culminate Medication overuse headache (MOH) can also be misdi- in a diagnosis of a secondary headache disorder, then the
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23. Cady RK, Schreiber CP. Sinus headache or migraine? Considerations in making a differential diagnosis. Neurology. dilemma that remains is whether or not the deviation from 2002;58(9 suppl 6):S10-S14. the usual headache pattern represents a new headache 24. Yoon,MS, Mueller D, Hansen N, et al. Prevalence of facial pain in migraine: a population-based study. Cephalalgia. 2010;30(1):92-96. disorder or is merely progression of the preexisting headache 25. Silberstein SD. Headaches due to nasal and paranasal sinus disease. Neurol Clin. 2004;22(1):1-19. disorder. Careful history must be taken to help distinguish via 26. Scelsa SN, Lipton RB, Sander H, Herskovitz S. Headache characteristics in hospitalized patients with Lyme disease. Headache. 1995;35(3):125-130. identification of triggers, trauma, or possible medication or 27. Hampson NB,Hampson LA. Characteristics of headache associated with acute carbon monoxide poisoning. Headache. substance overuse. 2002;42(3):220-223. 28. Lima Carvalho MF, de Medeiros JS, Valença MM. Headache in recent onset hypothyroidism: revalence, characteristics and outcome after treatment with levothyroxine. Cephalalgia. 2017;37(10):938-946. Conclusion 29. Candan FU. EHMTI-0229: a case of migraine like headache with postprandial hypoglycemia treated with lifestyle changing. J Headache Pain. 2014;15(suppl 1): G39. Given the wide range of symptoms and headache patterns 30. Jacome DE. Hypoglycemia rebound migraine. Headache. 2001;41(9): 895-898. that can be an expression of migraine, it can be difficult to 31. Kristoffersen ES, Lundqvist C. Medication-overuse headache: epidemiology, diagnosis and treatment. Ther Adv Drug Saf. 2014;5(2):87-99. properly diagnose migraine especially at an initial visit. False 32. Glanz B, Venkatesan A, Schur PH, Lew RA, Khoshbin S. Prevalence of migraine in patients with systemic lupus positives and false negatives of diagnosis often exist. There is an erythematosus. Headache. 2001;41(3):285-289. 33. Panayiotopoulos, CP. “Migralepsy” and the significance of differentiating occipital seizures for migraine. Epilepsia. overlap in headache quality and associated features, including 2006;47(4):806-808. autonomic signs, amongst different primary headache disor- ders. This overlap emphasizes the importance of thorough history taking when evaluating patients with headache; the Cynthia E. Armand, MD ability to find subtle features that a patient experiences can Assistant Professor of Neurology sometimes be paramount in making the appropriate diagno- Albert Einstein College of Medicine sis. Similarly, many secondary headache disorders can mimic Associate Headache Fellowship Director migraine and as a result may be overlooked, with potentially Montefiore Headache Center grave consequences. It is also beneficial to remember that a New York, NY person may have more than a single diagnosis; often comorbid conditions with migraine require a different, more expansive Alina Masters-Israilov, MD treatment approach. In the end, the answers to our evalu- Fellow, Headache and Facial Pain ation lie in a comprehensive history and physical exam that Department of Neurology should be challenged periodically, especially in the absence of Montefiore Medical Center improvement despite treatment. n New York, NY 1. Headache Classification Committee of the International Headache Society. The international classification of headache Richard B. Lipton, MD disorders, 3rd Edition. Cephalalgia. 2013; 33(9);629-808. 2. Goadsby PJ, Lipton RB. A review of paroxysmal hemicranias, SUNCT syndrome and other short-lasting headaches with Edwin S. Lowe Professor and Vice Chair of Neurology autonomic feature, including new cases. Brain. 1997;120(Pt 1):1983-2209. Professor of Epidemiology and Population Health 3. Uluduz D, Ayta S, Özge A, et al. Cranial autonomic features in migraine and migrainous features in cluster headache. Noro Psikiyatr Ars. 2018;55(3):220-224. Professor of Psychiatry and Behavioral Science 4. Newman LC, Goadsby P, Lipton RB. Cluster and related headaches. Med Clin North Am. 2001;85(4):997-1016. Director, Division of Cognitive Aging and Dementia 5. Prakash S, Adroja B. Hemicrania continua. Ann Indian Acad Neurol. 2018;21(suppl 1):S23-S30. 6. Newman LC, Lipton RB, Solomon S. Hemicrania continua: ten new cases and a review of the literature. Neurology. Director, Montefiore Headache Center 1994;44(11):2111-2114. Albert Einstein College Of Medicine 7. Rossi P, Faroni J, Tassorelli C,Nappi G. (2009), Diagnostic delay and suboptimal management in a referral population New York, NY with hemicrania continua. Headache. 2009;49(2):227-234. 8. Ali A, Kriegler J, Tepper S, Vij B. New daily persistent headache and onabotulinumtoxinA therapy. Clin Neuropharmacol. 2019;42(1):1-3. Disclosures 9. Nierenburg H, Newman LC. Update on new daily persistent headache. Curr Treat Options Neurol. 2016;18(6):25. 10. Ruiz M, Mulero P, Pedraza MI, et al. From wakefulness to sleep: migraine and hypnic headache association in a series of RBL receives research support from the National Institutes 23 patients. Headache. 2015;55(1):167-173. of Health, the Migraine Research Foundation and the 11. Dodick DW. Pearls: headache. Semin Neurol. 2010;30(1):74-81. 12. Donnelly A, Sinnott B, Boyle R, Rennie I. Beware the middle-aged migraine: internal carotid artery dissection mimick- National Headache Foundation; holds stock options in ing migraine in the emergency department. BMJ Case Rep. 2017;pii: bcr-2017-221774. eNeura Therapeutics and Biohaven Holdings; serves as 13. Mirza Z, Hayward P, Hulbert D. Spontaneous carotid artery dissection presenting as migraine—a diagnosis not to be missed. J Acad Emerg Med. 1998;15(3):187-199. consultant, advisory board member, or has received hono- 14. Singh R., Sahbudin, Filer A. New headaches with normal inflammatory markers: an early atypical presentation of giant raria from the American Academy of Neurology, Alder, cell arteritis. BMJ Case Rep. 2018;pii: bcr-2017-223240. Allergan, American Headache Society, Amgen, Autonomic 15. Fogang Y,Naeije G, Ligot N. Transient neurologic deficits: can transient ischemic attacks be discriminated from migraine aura without headache? J Stroke Cerebrovasc Dis. 2015;24(5):1047-1051. Technologies, Avanir, Biohaven, Biovision, Boston Scientific, 16. Lebedeva ER, Gurary NM, Olesen J. Headache in transient ischemic attacks. J Headache Pain. 2018;19(1):60. Dr. Reddy’s, Electrocore, Eli Lilly, eNeura Therapeutics, 17. Sina F, Razmeh S, Habibzadeh N, Zavari A, Nabovvati M. Migraine headache in patients with idiopathic intracranial hypertension. Neurol Int. 2017;9(3):7280. GlaxoSmithKline, Merck, Pernix, Pfizer, Supernus, Teva, 18. Lay CM. Low cerebrospinal fluid pressure headache. Curr Treat Options Neurol. 2002;4(5):357-363. Trigemina, Vector, Vedanta; and receives royalties from 19. Forsyth PA, Posner JB. Headaches in patients with brain tumors: a study of 111 patients. Neurology. 1993;43(9):1678-1683. 20. Gondim JA, de Almeida JP, de Albuquerque LA, Schops M, Gomes E, Ferraz T. Headache associated with pituitary Wolff’s Headache 7th and 8th Edition, Oxford Press tumors. J Headache Pain. 2009;10(1):15-20. University, 2009, Wiley, and Informa. CEA and AM-I have 21. Chen CH, Sheu JJ, Lin YC, Lin HC. Association of migraines with brain tumors: a nationwide population-based study. J no relationships relevant to this content to disclose. Headache Pain. 2018;19(1):111. 22. Angus-Leppan H. Migraine: mimics, borderlands and chameleons. Pract Neurol. 2013;13(5):308-318
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