Treatment of migraine attacks with intranasal alniditan: an open study

Current views of the risk of stroke for migraine with and migraine without aura

The association between migraine and stroke is complex and is a continued focus of attention. Several observational studies have identified migraine as an independent risk factor for ischemic stroke. However, a distinction should be made between migraine with and migraine without aura. The migraine-stroke association is mostly apparent for young women with migraine with aura. The association between migraine with aura and stroke is weaker in older age groups, which may be due to the fact that traditional cardiovascular risk factors are more prominent with increasing age. Most studies have not found an association between migraine without aura and ischemic stroke. Although there are several hypotheses about the biologic link between migraine with aura and ischemic stroke, the precise mechanisms remain unclear. However, because the absolute risk of stroke is low in patients with migraine with aura, and migraine without aura is likely not associated with ischemic stroke, most migraine patients will not experience a stroke event.

The importance of placebo in headache research

The best way to appreciate the efficacy of drug and behavioural therapy in the acute and prophylactic treatment of headache is to perform placebo-controlled randomized trials. In order to plan and conduct these studies in the most appropriate way, it is desirable to know which factors influence the placebo response. This paper reviews factors which influence the placebo response in clinical trials, such as expectation, blinding, route of application of drugs and age, gender and geographical distribution. Response rates of placebo in the treatment of acute headache episodes are higher than in headache prophylaxis. Invasive procedures such as injections have a higher placebo response compared with oral drugs. Variables known to influence the placebo response have to be taken into consideration to calculate properly the power of planned randomized trials.

Prevalence of patent foramen ovale in migraine patients with and without aura compared with stroke patients. A transcranial Doppler study

The aim of this study was to investigate the prevalence of patent foramen ovale (PFO) in a consecutive unselected cohort of migraine patients (with and without aura) and compare it with a group of ischaemic young and elderly stroke patients. One hundred and forty-one migraine patients were compared with 330 stroke patients (130 young patients; 200 elderly patients) selected from our hospital stroke data bank. PFO was assessed with transcranial Doppler sonography with i.v. injection of agitated saline. The prevalence of PFO was 51.7% in migraine with aura (MA) patients, 33.7% in migraine without aura (MoA) patients, 33.8% in young stroke patients and 20.5% in elderly stroke patients (P < 0.001). The prevalence of PFO in cryptogenic stroke in young and elderly stroke patients was, respectively, 41.1% and 25% (P = 0.04). The difference between MA and MoA patients was significant (odds ratio = 2.1). The prevalence of PFO in MA patients is higher than in MoA patients and in young cryptogenic stroke patients.

Patent foramen ovale: paradoxical connection to migraine and stroke

PURPOSE OF REVIEW

In this article we aim to elucidate the relationship between patent foramen ovale, cryptogenic stroke and migraine.

RECENT FINDINGS

Small observational and case-control studies indicate that patients with cryptogenic stroke have a higher incidence of patent foramen ovale. Prospective trials could not show a higher stroke recurrence risk with isolated patent foramen ovale. The combination of patent foramen ovale and atrial septal aneurysm might carry a higher recurrence risk. Secondary prevention with acetylsalicylic acid is as effective as oral anticoagulation, but carries a lower bleeding risk. Whether patent foramen ovale closure prevents recurrent strokes is under investigation. Case-control studies and retrospective analyses indicate comorbidity between patent foramen ovale and migraine, in particular migraine with aura. Recent retrospective studies indicate a reduction in migraine frequency after patent foramen ovale closure (intended for stroke prevention). These studies, however, have major methodological limitations. Therefore patent foramen ovale closure cannot be recommended for the prevention of migraine with aura.

SUMMARY

At present routine percutaneous closure of isolated patent foramen ovale cannot be recommended for patients with cryptogenic stroke. Patent foramen ovale closure should not be used for the prevention of migraine.

Acute treatments: some blind alleys

The introduction of sumatriptan, a selective 5-HT(1B/1D) agonist, for the treatment of migraine sparked a new era of drug research in this field. Many novel targets have since been developed, and tested in the clinic. The promise of these approaches is to deliver an anti-migraine compound with the optimal efficacy and safety profile. In this chapter, blind alleys in anti-migraine development are discussed. The failing soldiers have included the NK-1 antagonists, some second-generation 5-HT(1B/1D) agonists, CP-122,288, 4991W93, the neurosteroid ganaxolone, selective 5-HT(1F) (LY334370) and 5-HT(1D) agonists (PNU-142,633), and the endothelin-1 antagonist bosentan. Some of these promising targets failed to demonstrate clinical efficacy, while others were stopped for preclinical toxicity.