Proceedings of a Symposium Presented at the XXI World Congress of Neurology in Vienna, Austria, 24 September 2013
Expert Review by: Stefan Evers1 and Carlo Lisotto2
1. Professor of Neurology, University of Münster and Director, Department of Neurology, Krankenhaus Lindenbrunn, Germany; 2. Neurologist, Headache Centre, Department of Neurosciences, University of Padua, Italy
Migraine is a common disabling primary headache disorder. In the World Health Organization (WHO) Global Burden of Disease Survey 2010, it was ranked as the third most prevalent disorder and seventh-highest specific cause of disability worldwide.1,2 In 1991, the first triptan was released in Europe for use in acute migraine, followed by the US in 1993. Evidence-based treatment guidelines state that triptans are a first-line treatment option for migraines.3–5 However, triptans continue to be underutilised. There remains a false concern, among practitioners and patients, about possible safety issues, despite the evidence that triptans are safe and generally well tolerated. Following the publication of the third edition of the International Classification of Headache Disorders (ICHD),6 a satellite symposium, chaired by Stefan Evers, was held at the XXI World Congress of Neurology, Vienna, 21–26 September 2013. This article summarises the proceedings of the symposium, including changes to headache classifications, new guidelines regarding efficacy parameters in clinical trials, the importance of patient preference trials and clinical cases.
New Diagnostic and Severity Criteria for Migraine and Other Headaches – What is New?
Headache classification enables the implementation of a standardised and evidence-based approach to carrying out and reporting of clinical trials. Classification also allows effective management of migraine patients, especially when the diagnosis is uncertain. In the past, headache classification was based on pathophysiology, which was of limited use. More recent classifications have been based on phenomenology rather than pathology or aetiology. The ICHD third edition (ICHD-3 beta version) has recently been published.6 The beta (preliminary) version has been published ahead of the final version to enable field testing for inclusion in the WHO International Classification of Diseases, ICD-11, in 2016.
The following is a brief summary of what is new in ICHD-3 beta.
Primary and Secondary Headaches
- It is important to classify syndromes and not patients, such as avoiding the use of the term migraineur, and to recognise that a patient can have several headache types.
- When classifying headaches, specificity is more important than sensitivity: the aim is to have homogeneous patient groups and to have no doubt about a migraine diagnosis.
Changes in Primary Headache
- If patients fulfil the criteria for both chronic tension-type headache and chronic migraine, the latter should be the only diagnosis. Chronic tension-type headache should be the leading diagnosis over new daily persistent headache.
- Within the short-lasting unilateral neuralgiform headache attacks group, short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) has been included with shortlasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT).
- Hemicrania continua is now to be included as a trigeminal autonomic cephalalgia.
- A miscellaneous group includes new entities: cold-stimulus headache associated with the ingestion of cold food (e.g. eating ice cream) or inhalation of cold air, and external pressure headache resulting from external compression (e.g. a hat) or external traction.
- Nummular headache, a headache on the skull in the shape of a coin, has been included as a new entity.
- Epicrania fugax, a brief stabbing headache that stems from a particular area of the head, is included in the appendix and may be a discrete headache entity, but more studies are needed to confirm this.
Changes in Migraine
- Chronic migraine is now a specific subtype, rather than a complication of episodic migraine.
- Basilar migraine has been renamed migraine with brainstem aura, since symptoms originate from the brainstem.
- A new section of specific subtypes of migraine has been added: episodic syndromes that may be associated with migraine. These are regarded as precursors of migraine and may evolve in childhood or adolescence. They include recurrent gastrointestinal disturbances, cyclical vomiting syndrome, abdominal migraine and benign paroxysmal torticollis.
- Alternating hemiplegia may also be a precursor of migraine and is also included in the appendix.
Changes in Chronic Migraine
- Migraine with aura is now included in this category. This has been subdivided into migraine with typical aura, with or without headache, migraine with brainstem aura (previously termed basilar aura), hemiplegic migraine (now includes familial/sporadic subtypes) or retinal migraine.
- Chronic migraine may be diagnosed as a double diagnosis if medication overuse headache is also present (this was not allowed in the previous classification). However, withdrawal of medication overuse is recommended in order to make a final diagnosis.
Evaluation of the Efficacy of Migraine Treatment – New Guidelines
Defining parameters to assess drug efficacy within clinical trials is important. In addition, it has to be considered that the priorities of the patient often differ from those of the investigator. In recently published guidelines,7 the recommended primary endpoint in trials for acute migraine treatment is now the percentage of patients who are pain free within 2 hours. This has important implications for clinical studies for triptans. Most pivotal trials submitted for approval of acute migraine therapy in the US used pain response at 2 hours rather than other endpoints as primary measure of efficacy.