Calcitonin gene relating peptide inhibitors in combination for migraine treatment: A mini-review.

The discovery of calcitonin gene-related peptide (CGRP) and its role in migraine pathophysiology has led to advances in the treatment of migraine. Since 2018, the Food and Drug Administration (FDA) has approved four monoclonal antibody (mab) therapies targeting either the CGRP ligand or receptor and 3 oral small molecule CGRP receptor antagonists. These targeted therapies have been shown to be safe and effective for either preventive or acute treatment of migraine in adults. Given their efficacy and tolerability profile, CGRP inhibitors have revolutionized the approach to migraine treatment. Theoretically, combining therapies within this therapeutic class could lead to more CGRP blockade and, subsequently, improved patient outcomes. There are providers currently combining CGRP therapies in clinical practice. However, limited data are available regarding the efficacy and safety of this practice. This mini-review provides a summary of available data and poses important considerations when combining CGRP therapies for migraine treatment.

Safety and tolerability of preventive treatment options for chronic migraine.

INTRODUCTION: Relative to migraine generally, chronic migraine (CM) imposes greater disability, healthcare utilization and socioeconomic burden. Six therapies currently possess a credible evidence base for prevention/suppression of CM. This review is intended to provide an assessment of their relative utility, defined as a blend of safety, tolerability and efficacy, focusing in particular on their safety and tolerability.Areas Covered: We discuss all six medications currently FDA-approved for migraine prevention which also specifically possess credible evidence of efficacy in treating CM. While we do address the efficacy of each, our primary emphasis involves assessment of safety and tolerability data derived from clinical trials and post-marketing experience.Expert Opinion: Recent research involving CM has led to the identification of highly targeted and typically well-tolerated therapies. For patients who experience obstacles to accessing these newer therapies, topiramate is available as an evidence-based alternative, but contraindications, drug-drug interactions and poor tolerability may limit or prevent its use. Although data to support such intervention presently is limited, clinically challenging CM cases may benefit from combination therapy. 'Real world' studies are needed to evaluate such polytherapy, along with studies intended to assess the long-term safety of the individual therapies and their use during pregnancy and breast-feeding.

Prognosis Following Discontinuation of OnabotulinumA Therapy in "Super-responding" Chronic Migraine Patients.

OBJECTIVE: To determine whether the successful treatment of chronic migraine (CM) with onabotulinumA (BotoxA) may be followed by a continued respite from headache once therapy has been discontinued. BACKGROUND: The optimal duration of prophylactic therapy for migraine generally and for CM treated with BotoxA specifically is unknown. METHODS: We conducted a prospective cohort study evaluating a series of patients with CM at a university-affiliated headache subspecialty clinic in Reno, Nevada, all of whom were treated according to a uniform protocol involving serial injections of BotoxA. We followed all positively responding patients who met our stopping rule for a minimum of 6 months after discontinuation of BotoxA, and we assessed the incidence of clinical worsening in that group. RESULTS: A total of 105/131 patients (80%) for whom complete follow-up was available reported no clinical worsening or need to resume prophylactic therapy over the 6 months following discontinuation of BotoxA therapy. Patients with pre-treatment baseline chronic daily headache (CDH) of greater than 6 months duration were more likely to report clinical deterioration within 6 months of stopping treatment, as compared to patients with CDH of less than 6 months. A greater number of BotoxA treatments required to achieve our stopping rule correlated with clinical deterioration within 6 months of stopping treatment. CONCLUSIONS: In many CM patients who experience an especially positive response to serial BotoxA injection therapy, clinical improvement may be sustained for a period of at least 6 months following discontinuation of prophylactic therapy.

What Are We Missing in the Diagnostic Criteria for Migraine?

PURPOSE OF REVIEW: This review is intended to examine how the diagnostic criteria for migraine have evolved over the past 45 years and to evaluate the strengths and weaknesses of the current diagnostic criteria promulgated by the International Classification of Headache Disorders (ICHD). RECENT FINDINGS: The ICHD is a comprehensive and systematic classification system for headache disorders. As the pathophysiology of migraine is more fully elucidated and more sophisticated diagnostic technologies are developed (e.g., the identification of biomarkers), the current diagnostic criteria for migraine will likely be further refined. The ICHD has allowed for more precise research study design in the field of headache medicine. The current diagnostic criteria for migraine outlined in the 3rd version of the ICHD are far more sensitive and specific than the clinical criteria proposed in 1962. In future iterations, dividing episodic and chronic migraine into subtypes based on frequency (i.e., low frequency vs high frequency; near-daily vs daily) potentially could assist in guiding clinical management. In addition, a better understanding of aura, vestibular migraine, migrainous infarction, and hemiplegic migraine likely will lead to more refined diagnostic criteria for those entities.

A gradient of auxin and auxin-dependent transcription precedes tropic growth responses.

Plants, although sessile, can reorient growth axes in response to changing environmental conditions. Phototropism and gravitropism represent adaptive growth responses induced by changes in light direction and growth axis orientation relative to gravitational direction, respectively. The nearly 80-year-old Cholodny-Went theory [Went, F. W. & Thimann, K. V. (1937) Phytohormones (Macmillan, New York)] predicts that formation of a gradient of the plant morphogen auxin is central to the establishment of tropic curvature. Loss of tropic responses in seedling stems of Arabidopsis thaliana mutants lacking the auxin-regulated transcriptional activator NPH4/ARF7 has further suggested that a gradient of gene expression represents an essential output from the auxin gradient. Yet the molecular identities of such output components, which are likely to encode proteins directly involved in growth control, have remained elusive. Here we report the discovery of a suite of tropic stimulus-induced genes in Brassica oleracea that are responsive to an auxin gradient and exhibit morphologically graded expression concomitant with, or before, observable curvature responses. These results provide compelling molecular support for the Cholodny-Went theory and suggest that morphologically graded transcription represents an important mechanism for interpreting tropically stimulated gradients of auxin. Intriguingly, two of the tropic stimulus-induced genes, EXPA1 and EXPA8, encode enzymes involved in cell wall extension, a response prerequisite for differential growth leading to curvatures, and are up-regulated before curvature in the flank that will elongate. This observation suggests that morphologically graded transcription likely leads to the graded expression of proteins whose activities can directly regulate the establishment and modulation of tropic curvatures.