Epidemiology of migraine pain Welcome to this presentation in the series “Know Migraine Pain”. In this module we will review the epidemiology of migraine pain.

WHAT IS MIGRAINE? In this first section we’ll discuss the question “What is Migraine?”.

Headache Disorders Among the most common disorders of the nervous system1 Prevalence among adults (symptomatic at least once within the last year) is almost 47% worldwide1 Associated with personal and societal burdens of pain, disability, reduced quality of life, and financial burden1 Globally, only a minority of people with headache disorders are appropriately diagnosed by a health care provider1 Headache has been underestimated, under-recognized, and under-treated throughout the world1 Here’s a brief overview of headache disorders. The are among the most common disorders of the nervous system. Their prevalence among adults who are symptomatic at least once within the last year is almost 47% worldwide. Headache disorders are associated with personal and societal burdens of pain, disability, reduced quality of life, and financial burden. However, globally, only a minority of people with headache disorders are appropriately diagnosed by a health care provider. Thus, headache has been underestimated, under-recognized, and under-treated throughout the world. 1. WHO 2012. Headache disorders. Available at: http://www.who.int/mediacentre/factsheets/fs277/en/

Structures Related to Headache This schematic gives an overview of the structures related to headache. These include blood vessels, muscles in the neck and head, joints, cranial nerves, teeth, sinuses, and the muscles around the eyes. Please take a moment to review this schematic.

What Is Migraine? Neurologically based, common clinical syndrome characterized by recurrent episodic attacks of head pain which serve no protective purpose The headache is accompanied by associated symptoms Nausea Sensitivity to light Sensitivity to sound Sensitivity to head movement The vulnerability to migraine is an inherited tendency in many people Moving on, we can define migraine as a neurologically based, common clinical syndrome characterized by recurrent episodic attacks of head pain which serve no protective purpose. In migraine the headache is accompanied by associated symptoms, including nausea, sensitivity to light, and sensitivity to sound, sensitivity to head movement. The vulnerability to migraine is an inherited tendency in many people Lance JW, Goadsby PJ. Mechanism and Management of Headache. London, England: Butterworth-Heinemann; 1998;; Silberstein SD, Lipton RB, Goadsby PJ. Headache in Clinical Practice. 2nd ed. London, England: Martin Dunitz; 2002 Olesen J, Tfelt-Hansen P, Welch KMA. The Headaches. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2000.

Classification of Migraine Migraine without aura Recurrent attacks, lasting minutes, of unilaterally fully reversible visual, sensory, or other CNS symptoms that usually develop gradually and are usually followed by headache and associated migraine symptoms Migraine with typical aura Aura consists of visual and/or sensory and/or speech/language symptoms but no motor weakness Gradual development Duration of each symptom ≤1 hour Mix of positive and negative features Complete reversibility Chronic Migraine Headache occurring on ≥15 days/month for >3 months Headache has the features of migraine headache on ≥8 days/month Three basic types of migraine exist. First, the migraine without aura is characterized by recurrent attacks, lasting minutes, of unilaterally fully reversible visual, sensory, or other CNS symptoms that usually develop gradually and are usually followed by headache and associated migraine symptoms. Second, the migraine with typical aura is characterized by an aura consists of visual and/or sensory and/or speech/language symptoms but no motor weakness. This aura develops gradually, with a symptom duration of more than an hour, and is characterized by a mix of positive and negative features. Migraine with the typical aura is completely reversible. Finally, chronic Migraine is defined as headache occurring on 15 days or more per month for more than 3 months. Headache with the features of migraine headache occurs on 8 days or more per month. International Headache Society. 2013

Primary vs. Secondary Headache Primary Headache Not a symptom of or caused by another disease or condition Secondary Headache A symptom of or caused by an underlying disease or condition, such as tumor or infection Headache can also be classified as primary headache, which is not a symptom of or caused by another disease or condition, or secondary headache, which is a symptom of or caused by an underlying disease or condition, such as tumor or infection. Mayo Clinic. Headache causes – symptoms. Available at: http://www.mayoclinic.org/symptoms/headache/basics/causes/sym-20050800. Accessed 15 January 2015.

Prevalence of Headache Disorders by Headache Type Lifetime Prevalence Primary Headache Disorders Tension-type Migraine 78% 16% Secondary Headache Disorders Fasting Sinus/nasal disorder Head injury Non-vascular intracranial disorder* 19% 15% 4% 0.5% This table gives a breakdown of the prevalence of primary and secondary headache disorders. *Including brain tumor Rasmussen BK et al. J Clin Epidemiol. 1991;44(11):1147-57.

Age- and Gender-Specific Prevalence of Migraine In males and females, the prevalence distribution of migraine is an inverted U-shaped curve. Prevalence rises through early adult life and then falls after midlife in both genders. At all postpubertal ages, migraine is substantially more common in women than in men. Lipton RB et al. Headache. 2001;41(7):646-57.

Prevalence of Migraine in Three Population-based Studies The annual incidence of migraine among women is about 18%, which is triple the incidence among men. Migraine is the headache that drives patients to seek medical help, and most of these patients are women. Stewart WF et al. JAMA. 1992;267(1):64-9; Lipton RB et al. Headache. 2001;41(7):646-57; Lipton RB et al. Neurology. 2007 Jan 30;68(5):343-9.

Prevalence of Migraine by Ethnicity Estimates of migraine prevalence from African American and Asian American populations are lower than those observed in Caucasian American populations. These differences in prevalence are more likely caused by race-related differences in genetic vulnerability to migraine than to cultural differences. Stewart WF et al. Neurology. 1996;47(1):52-9.

Prevalence of Headache Disorders by Geographic Area The prevalence in headache is greater in Europe and the Americas than in Africa and Asia. In all parts of the world headaches are more prevalent in women than in men. Lipton RB et al. J Headache Pain. 2003;4[Suppl 1]:S3-S11.

Specific Types of Secondary Headaches Type of Headache Cause External compression Pressure-causing head gear Rebound Overuse of pain medication Sinus Inflammation and congestion in sinus cavities Spinal Low levels of cerebrospinal fluid (e.g., due to trauma, spinal tap, spinal anesthesia) Thunderclap Subarachnoid haemorrhage is the most common cause This slide lists the most common causes of secondary headaches and their causes. An ice cream headache – or brain freeze – is a secondary headache Mayo Clinic. Headache causes – symptoms. Available at: http://www.mayoclinic.org/symptoms/headache/basics/causes/sym-20050800. Accessed 15 January 2015; Ducros A, Bousser MG. BMJ. 20138;346:e8557.

Prevalence of Headache Disorders Top Five Reasons for Emergency Department Visits* Headache is the fifth leading cause of emergency department visits in the United States, estimated to account for over 4 million visits each year. Among women, it rises to third place, accounting for 2.6% of emergency department visits in that group. *National Hospital Ambulatory Medical Care Survey, 2009 Smitherman TA et al. Headache. 2013;53(3):427-36.

Depression, Anxiety, and Migraine This slide illustrates the prevalence and severity of anxiety and depression among people with migraine. Anxiety and depression are common among people with migraine and remain largely unrecognized. HAD = J Devlen. J R Soc Med. 1994;87(6):338-41.

Prevalence of Psychiatric Disorders in Three Pain Conditions No Migraine Migraine Odds Ratio (CI) Depression 12.3% 28.5% 2.84 (2.19, 3.70) Panic attacks 5.5% 17.4% 3.58 (2.59, 4.97) GAD 2.5% 9.1% 3.86 (2.48, 6.00) No Arthritis Arthritis Odds Ratio 13.1% 18.2% 1.48 (1.16, 1.88) 5.8% 11.2% 2.09 (1.54, 2.83) 2.7% 5.6% 2.17 (1.42, 3.33) No Back Pain Back Pain 12.4% 21.0% 1.87 (1.49, 2.36) 5.3% 13.0% 2.69 (2.00, 3.62) 6.2% 2.54 (1.67, 3.85) This slide illustrated the prevalence of depression and anxiety disorders associated with migraine, arthritis, and back pain. Note that Migraine is more strongly associated with both depression and anxiety disorders than arthritis or back pain. All findings significant at p<0.001 CI = confidence interval; GAD = generalized anxiety disorder McWilliams LA et al. Pain. 2004;111(1-2):77-83.

Migraine and Depression: A Bidirectional Relationship with Common Neurobiology Monoamine and peptide transmitters may be involved in depression Endorphins and encephalins are involved in mood and pain control Serotonin has been implicated in migraine, and tension-type headache Also implicated in mood disorders, anxiety disorders, sleep disorders, eating disorders, and obsessive-compulsive behavior Evidence suggests dopamine is involved in migraine Migraine prodrome often characterised by dopaminergic symptoms Anti-dopaminergic drugs can often be helpful in treating migraine Migraine and depression share a bidirectional relationship with common neurobiology. Specifically, monoamine and peptide transmitters may be involved in depression, and endorphins and encephalins are involved in mood and pain control. Serotonin has been implicated in migraine, and tension-type headache, and it is also implicated in mood, anxiety, sleep, eating and disorders, as well as in obsessive-compulsive behavior. Dopamine may also be involved in the pathophysiology. Specifically, the migraine prodrome often characterised by dopaminergic symptoms, and anti-dopaminergic drugs can often be helpful in treating migraine. Thus, severe headache, severe somatic symptoms, and major depression may be linked through dysfunction of the serotonergic and dopaminergic systems. Severe headache, severe somatic symptoms, and major depression may be linked through dysfunction of the serotonergic and dopaminergic systems Frediani F, Villani V. Migraine and depression. Neurol Sci. 2007;28 Suppl 2:S161-5.

Literature Cited Devlen, J. (1994). Anxiety and depression in migraine. Journal of the Royal Society of Medicine, 87(6), 338–341. Frediani, F., & Villani, V. (2007). Migraine and depression. Neurological Sciences: Official Journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 28 Suppl 2, S161–165. http://doi.org/10.1007/s10072-007-0771-7 Goadsby, P. J., Lipton, R. B., & Ferrari, M. D. (2002). Migraine—current understanding and treatment. N Engl J Med, 346(4), 257–270. Headache Causes - Mayo Clinic. (n.d.). Retrieved June 18, 2015, from http://www.mayoclinic.org/symptoms/headache/basics/causes/sym-20050800 (IHS, H. C. C. of the I. H. S. (2013). The international classification of headache disorders, (beta version). Cephalalgia, 33(9), 629–808. Lipton, R. B., Bigal, M. E., Diamond, M., Freitag, F., Reed, M. L., Stewart, W. F., & AMPP Advisory Group. (2007). Migraine prevalence, disease burden, and the need for preventive therapy. Neurology, 68(5), 343–349. http://doi.org/10.1212/01.wnl.0000252808.97649.21 Lipton, R. B., Stewart, W. F., Diamond, S., Diamond, M. L., & Reed, M. (2001). Prevalence and burden of migraine in the United States: data from the American Migraine Study II. Headache, 41(7), 646–657.

Literature Cited (Continued) McWilliams, L. A., Goodwin, R. D., & Cox, B. J. (2004). Depression and anxiety associated with three pain conditions: results from a nationally representative sample. Pain, 111(1-2), 77–83. http://doi.org/10.1016/j.pain.2004.06.002 Olesen, B., Tfelt-Hansen, P., & Welch, K. (2000). The Headaches (2nd ed.). Philadelphia pA: Lippincott, Williams & Wilkins. Rasmussen, B. K., Jensen, R., Schroll, M., & Olesen, J. (1991). Epidemiology of headache in a general population--a prevalence study. Journal of Clinical Epidemiology, 44(11), 1147–1157. Silberstein, S., Lipton, R., & Goadsby PJ. (2002). Headache in Clinical Practice. (2 nd ed.). London: Martin Dunitz. Smitherman, T. A., Burch, R., Sheikh, H., & Loder, E. (2013). The prevalence, impact, and treatment of migraine and severe headaches in the United States: a review of statistics from national surveillance studies. Headache, 53(3), 427–436. http://doi.org/10.1111/head.12074 Stewart, W. F., Lipton, R. B., Celentano, D. D., & Reed, M. L. (1992). Prevalence of migraine headache in the United States. Relation to age, income, race, and other sociodemographic factors. JAMA, 267(1), 64–69. Stewart, W. F., Lipton, R. B., & Liberman, J. (1996). Variation in migraine prevalence by race. Neurology, 47(1), 52–59.

Literature Cited (Continued 2) WHO | Headache disorders. (n.d.). Retrieved June 18, 2015, from http://www.who.int/mediacentre/factsheets/fs277/en/