Headache disorders are among the most common disorders of the nervous system. Despite the significant disability caused by headache disorders, they remain underdiagnosed and undertreated and often patient needs are unmet. Migraine and cluster headache are two types of primary headache disorders, both of which impose substantial burden on patients and the health care system. Migraine and cluster headache are usually treated in the primary care setting; therefore, it is important for clinicians to understand the differences between these primary headache disorders, address barriers to care, and work with patients on an individualized treatment plan.
Migraine vs Cluster Headache
The Migraine Research Foundation reports that migraine affects 38 million patients in the United States and the majority are women, with about 1 in 4 women experiencing a migraine in their lifetime. The condition is most commonly experienced between the ages of 25 and 55, and about 90% of patients have a family history of migraine.
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Whereas, cluster headache—the most common of the family of headache disorders known as trigeminal autonomic cephalagias—has a lifetime prevalence of about 1 in 1000 US adults. Age of onset is usually 20 to 40 years, and the overall male to female ratio is 4.3, according to a 2013 study in the American Family Physician.
The International Classification of Headache Disorders (ICHD), third edition (beta version) classifies migraine into two major subtypes: migraine without aura and migraine with aura. Migraine without aura is a recurrent disorder manifesting in attacks (at least five) lasting 4 to 72 hours. Typical characteristics of the headache are unilateral location, pulsating quality, moderate or severe intensity, aggravation by routine physical activity and association with nausea and/or photophobia and phonophobia. Migraine with aura is recurrent attacks (at least 2 attacks), lasting minutes, of unilateral fully reversible visual, sensory, or other central nervous symptoms that develop slowly and are usually followed by headache and associated migraine symptoms.
Cluster headache is divided into chronic and episodic categories based on the duration and frequency of episodes. The ICHD classified cluster headache as severe unilateral temporal or periorbital pain lasting 15 to 180 minutes and occurring once every other day to eight times a day.
Disease Burden and Challenges
The economic burden of migraine is a key cost driver in the US population. A 2016 study published in Journal of Pain that analyzed 10-year national trends (2003 to 2013) in direct health expenditures among individuals with migraines showed the unadjusted average annual total expenditure for individuals with migraine was $8033, which equates to $56 billion per year to the US health care system.
Barriers to diagnosis and treatment of migraine and cluster headache have been identified. The Chronic Migraine Epidemiology and Outcomes Study published in 2016 in Headache found that less than 5% of individuals with chronic migraine successfully traversed three barriers to successful chronic migraine care (ie, consulted a health care professional for migraine, received an accurate diagnosis, and were prescribed a minimal acute and preventive pharmacologic treatment), underscoring a large unmet need for improving care in this population.
Data from the United States Cluster Survey found a significant diagnostic delay for patients with cluster headache on average of 5 or more years with only 21% receiving the correct diagnosis at time of initial presentation.
Clinicians need to consider the patient’s expectations, needs, and goals when developing a migraine management plan, which includes behavioral management, acute/abortive treatment, and preventive therapy. A wide range of pharmacotherapies are available including migraine-specific medications such as triptans. The American Headache Society (AHS) has published evidence-based recommendations for the acute pharmacologic treatment of migraine.
For moderate to severe attacks, triptans are recommended as first-line therapy. Triptans are class of selective and highly effective 5-HT1B/1D receptor agonists. Currently, seven triptans are commercially available: sumatriptan, naratriptan, zolmitriptan, rizatriptan, eletriptan, frovatriptan, and almotriptan. A 2016 study published in Drug Design, Development and Therapy found that triptans remain the preferred treatment option among the majority of patients and physicians for acute treatment of adult migraine. Triptans are available via multiple delivery systems (eg, oral, subcutaneous injection, and nasal spray).
Advances in therapies for acute and preventive migraine treatment are in development and include compounds acting on calcitonin gene-related peptide or its receptor, 5-HT1F receptor, nitric oxide synthase, and acid-sensing ion channel blockers.
Treatment of cluster headache can be challenging and requires a dual strategy including acute and prophylactic treatment, as well as strategies that involve avoidance of possible triggers to attacks. The AHS recently published new evidence-based guidelines for cluster headache. Sumatriptan, subcutaneous zolmitriptan nasal spray, and high flow oxygen remain the Level A recommended treatment for acute cluster headache.
The guideline authors acknowledged that some commonly used preventive therapies do not have Class I evidence and Level A recommendations, noting that further studies are warranted to demonstrate the safety and efficacy in these established therapies as well as emerging therapies. Among the maintenance and preventative therapies available, verapamil is generally considered as the maintenance prophylactic therapy of choice for cluster headache despite only a Level C (possibly effective) recommendation, according to the guideline.
“It would be nice to see medications in development that are specifically directed at cluster headache treatment, as the available medications now are without exception borrowed from other indications,” wrote Dr Mark Obermann and colleagues in a 2015 study in Expert Opinion on Pharmacotherapy.