Current Concepts in Refractory Migraine

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

INTRODUCTION

It has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.

DEVELOPMENT

The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.

CONCLUSIONS

The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.

Systematic review of the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion for the treatment of refractory chronic cluster headache

INTRODUCTION

This study aimed to assess the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion (SPG) in the treatment of refractory chronic cluster headache.

DEVELOPMENT

Various medical databases were used to perform a systematic review of the scientific literature. The search for articles continued until 31 October 2016, and included clinical trials, systematic reviews and/or meta-analyses, health technology assessment reports, and clinical practice guidelines that included measurements of efficiency/effectiveness or adverse effects associated with the treatment. The review excluded cohort studies, case-control studies, case series, literature reviews, letters to the editor, opinion pieces, editorials, and studies that had been duplicated or outdated by later publications from the same institution. Regarding effectiveness, we found that SPG stimulation had positive results for pain relief, attack frequency, medication use, and patients' quality of life. In the results regarding safety, we found a significant number of adverse events in the first 30 days following the intervention. Removal of the device was necessary in some patients. Little follow-up data, and no long-term data, is available.

CONCLUSIONS

These results are promising, despite the limited evidence available. We consider it essential for research to continue into the safety and efficacy of SPG stimulation for patients with refractory chronic cluster headache. In cases where this intervention may be indicated, treatment should be closely monitored.

Systematic review of the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion for the treatment of refractory chronic cluster headache

INTRODUCTION

This study aimed to assess the safety and effectiveness of peripheral neurostimulation of the sphenopalatine ganglion (SPG) in the treatment of refractory chronic cluster headache.

DEVELOPMENT

Various medical databases were used to perform a systematic review of the scientific literature. The search for articles continued until 31 October 2016, and included clinical trials, systematic reviews and/or meta-analyses, health technology assessment reports, and clinical practice guidelines that included measurements of efficiency/effectiveness or adverse effects associated with the treatment. The review excluded cohort studies, case-control studies, case series, literature reviews, letters to the editor, opinion pieces, editorials, and studies that had been duplicated or outdated by later publications from the same institution. Regarding effectiveness, we found that SPG stimulation had positive results for pain relief, attack frequency, medication use, and patients' quality of life. In the results regarding safety, we found a significant number of adverse events in the first 30 days following the intervention. Removal of the device was necessary in some patients. Little follow-up data, and no long-term data, is available.

CONCLUSIONS

These results are promising, despite the limited evidence available. We consider it essential for research to continue into the safety and efficacy of SPG stimulation for patients with refractory chronic cluster headache. In cases where this intervention may be indicated, treatment should be closely monitored.

[Diagnosis of refractory forms of chronic primary headache]

A number of patients with primary headaches remain insensitive or refractory to treatment despite correctly selected drugs, adequate therapeutic dose and duration of therapy. The importance of refractory problem is determined by the fact that patients are completely maladjusted, disabled, and keeping these patients is very difficult even for seasoned professionals. Determination of the correct tactics and success of the treatment depends, in the first place, on the correct diagnosis. This article discusses the diagnostic criteria for the most important forms such as refractory chronic migraine or refractory chronic cluster headache presented by experts of the European Headache Federation in two separate Consensus.

Providing Care for Patients with Chronic Migraine: Diagnosis, Treatment, and Management

Chronic migraine, a subtype of migraine defined as ≥ 15 headache days per month for ≥ 3 months, in which ≥ 8 days per month meet criteria for migraine with or without aura or respond to migraine-specific treatment, is a disabling, underdiagnosed, and undertreated disorder associated with significant disability, poor health-related quality of life, and high economic burden. The keys to caring for chronic migraine patients include: (1) making a proper diagnosis; (2) identifying and eliminating exacerbating factors; (3) assessing for medication overuse (patients with chronic headache often overuse acute medications); and (4) continued management. Communication between patient and physician about treatment goals is important. The patient management guidelines presented in this article should help physicians improve treatment success and proactively address common comorbidities among their patients with chronic migraine.

Tackling chronic migraine: current perspectives

In the last decade, several diagnostic criteria and definitions have been proposed for chronic migraine (CM). The third edition of the International Classification of Headache Disorders–3 beta, published in 2013, has revised CM diagnostic criteria. CM is defined as “headache occurring on 15 or more days per month for more than 3 months, which has the features of migraine headache on at least 8 days per month.” Patients who meet the criteria for CM and for medication-overuse headache should be given both diagnoses. Worldwide, CM prevalence ranges 1%–3%, and its incidence has been estimated to be 2.5% per year. CM is associated with disability and poor quality of life. Modifiable risk factors include (among others): migraine progression (defined as an increase in frequency and severity of migraine attacks); medication and caffeine overuse; obesity; stressful life events; and snoring. CM patients have a significantly higher frequency of some comorbid conditions, including chronic pain, psychiatric disorders, respiratory illness, and some vascular risk factors. Management includes identification and control of comorbidities and risk factors that predispose to CM; treatment and prevention for medication overuse; early treatment for migraine attacks; and an adequate preventive therapy for CM. Several randomized controlled clinical trials have shown the efficacy of topiramate, amitriptyline, onabotulinumtoxinA, and cognitive-behavioral therapy in CM.

Refractory migraine: the role of the physician in assessment and treatment of a problematic disease

Patients affected by chronic forms of headache are often very difficult to treat. Refractory patients are so defined when adequate trials of specific drugs (for acute or prophylactic treatment) failed both to reduce the burden of disease and to improve headache-related quality of life. An escalating approach is suggested to test different kinds of therapies. All comorbid factors should be addressed. More invasive modalities (such as neurostimulation) or promising approaches such as repetitive transcranial magnetic stimulation (rTMS) could be a future major step as third line therapies.