Genetics of migraine: complexity, implications, and potential clinical applications.

Migraine is a common neurological disorder with large burden in terms of disability for individuals and costs for society. Accurate diagnosis and effective treatments remain priorities. Understanding the genetic factors that contribute to migraine risk and symptom manifestation could improve individual management. Migraine has a strong genetic basis that includes both monogenic and polygenic forms. Some distinct, rare, familial migraine subtypes are caused by pathogenic variants in genes involved in ion transport and neurotransmitter release, suggesting an underlying vulnerability of the excitatory-inhibitory balance in the brain, which might be exacerbated by disruption of homoeostasis and lead to migraine. For more prevalent migraine subtypes, genetic studies have identified many susceptibility loci, implicating genes involved in both neuronal and vascular pathways. Genetic factors can also reveal the nature of relationships between migraine and its associated biomarkers and comorbidities and could potentially be used to identify new therapeutic targets and predict treatment response.

Headache Attributed to Refractive Error: Improvement after Topography-Guided Photorefractive Keratectomy with Corneal Cross-Linking in Patients with Keratoconus.

PURPOSE: To investigate if topography-guided photorefractive keratectomy (TGPRK) alleviates headache, particularly headache attributed to refractive errors (HARE) in keratoconus. METHODS: Patients diagnosed with keratoconus undergoing TGPRK for refractive correction were included. Best spectacle corrected visual acuity (BSCVA) using the logMAR scale and refractive error were measured. Patients answered a questionnaire exploring headaches, characteristics, treatment, and the Headache Impact Test (HIT-6) before and 6 months after the surgery. RESULTS: 40 patients were included. Preoperatively, 24 patients (60%) met criteria for headaches: five for migraine, 14 for HARE, and five for tension-type headache (TTH). Patients with headaches preoperatively were more likely to require bilateral TGPRK, and the mean sphere and cylindrical power were higher. Postoperatively, 15 out of the 24 patients of the headache group experienced complete resolution of headaches, and only nine patients met diagnostic criteria for headaches: two for migraine, six for HARE, and one for TTH. The number of headaches reduced from 4.4 ± 2.4 to 0.5 ± 0.7 days/week (p < 0.001). Headache duration decreased from 108.5 ± 100.7 min to 34.4 ± 63.5 min (p = 0.002). Postoperatively, the consumption of analgesia decreased. The HIT-6 revealed an improvement in the quality-of-life post-procedure (p < 0.001). CONCLUSIONS: Surgical correction of irregular astigmatism in patients with keratoconus can alleviate or resolve headaches in a large proportion of patients, resulting in an improvement in their quality of life. Physicians should consider keratoconus in patients fitting criteria for HARE not alleviated by spectacle correction and suboptimal vision in glasses.

Migraine in older adults.

Migraine is an evolving, and sometimes lifelong disorder. The prevalence of episodic migraine peaks among individuals aged in their late 30s, implying a tendency for the disorder to remit with increasing age thereafter, whereas chronic migraine is more likely to persist into later life. Diagnosis and treatment of migraine in older adults, defined as individuals aged 60 years or older, is rendered more complex by increasing probabilities of atypical clinical features and comorbidities, with patients' comorbidities sometimes limiting their therapeutic options. However, the changing clinical presentation of migraine over an individual's lifespan is not well characterised. The neurobiological basis of remission in older adults remains unclear, although vascular, neuronal, and hormonal changes are likely to be involved. Long-term longitudinal studies of individuals with migraine would be particularly informative, with the potential not only to suggest new research directions, but also to lead to the identification of novel therapeutic agents. Although several novel migraine medications are becoming available, their effectiveness, tolerability, and safety often remain uncertain in older adults, who have commonly been excluded from the evaluation of these agents in randomised controlled trials, or who constitute only a small proportion of study populations. There is a need to recognise these limitations in the available evidence, and the specific, and often unmet, clinical needs of older adults with migraine, not least because older adults constitute an increasing proportion of populations worldwide.

Assessing and managing medication overuse headache in Australian clinical practice.

More than 3 million Australians are estimated to have migraine disorders, and over a quarter of a million Australians are estimated to have medication overuse headache (MOH). The personal, societal and economic burden of MOH is high. MOH impacts an individual's ability to work or study, care for family or themselves, culminating in poor quality of life. Accurate and timely diagnosis and treatment of MOH are imperative. Withdrawal failures and relapse rates are high in MOH. Treatment of MOH is aimed at ceasing medication overuse and reducing monthly migraine days with the aim of achieving a pattern of well-controlled episodic migraine. Current treatment approaches in routine practice include withdrawal with preventive treatment, withdrawal with optional preventive treatment in the subsequent weeks and preventive treatment without withdrawal. This viewpoint article provides an overview of managing MOH in Australian clinical practice, with a focus on the importance of patient education and the role of preventive treatment in supporting patients as they withdraw from acute migraine medication(s).

Practical Insights on the Identification and Management of Patients with Chronic Migraine.

Chronic migraine (CM) is one of the most disabling diseases, and it is commonly misdiagnosed and mistreated. Despite the importance of a timely and accurate diagnosis for the effective management of CM, recent surveys have shown that only 20-25% of individuals with CM receive a correct diagnosis. The obvious consequences of misdiagnosed CM are prolongation of symptoms and their associated effects on disability and health-related quality of life. Additionally, mistreatment of CM can lead to acute medication overuse headache with escalation of headache and end organ damage. Ideally, a diagnosis of CM should be made in the primary care setting, based on a thorough medical history including detailed descriptions of headaches occurring earlier in life as well as current headaches, and the range of headaches (not just the worst headaches). In our experience, it is often equally informative to ask the patient about the number of headache-free days (HFDs) and no accompanying symptoms (i.e., crystal-clear days) to quantify headache days and accurately estimate headache frequency/impact. Headache frequency is important, as this count is one key means of diagnosing CM, which requires ≥ 15 headache days/month, noting that these do not need to be migraine days. A headache day is defined as more than 4 h a day of headache. Comorbidities are common in CM and may affect the treatment choice and increase disability. Every CM patient should be offered a preventive migraine treatment. In this commentary, we provide practical insights and tips for diagnosing CM and cover issues of medication overuse, patient communication, diagnostic testing, and when to make a referral. Our key message to physicians for a patient who comes to the clinic with frequent disabling headaches having features of migraine is to assume CM until proven otherwise.

Comprehensive Exonic Sequencing of Hemiplegic Migraine-Related Genes in a Cohort of Suspected Probands Identifies Known and Potential Pathogenic Variants.

Hemiplegic migraine (HM) is a rare migraine disorder with aura subtype including temporary weakness and visual, sensory, and/or speech symptoms. To date, three main genes-CACNA1A, ATP1A2, and SCN1A-have been found to cause HM. These encode ion channels or transporters, important for regulating neuronal ion balance and synaptic transmission, leading to HM being described as a channelopathy. However, <20% of HM cases referred for genetic testing have mutations in these genes and other genes with roles in ion and solute transport, and neurotransmission has also been implicated in some HM cases. In this study, we performed whole exome sequencing for 187 suspected HM probands referred for genetic testing, but found to be negative for CACNA1A, ATP1A2, and SCN1A mutations, and applied targeted analysis of whole exome sequencing data for rare missense or potential protein-altering variants in the PRRT2, PNKD, SLC1A3, SLC2A1, SLC4A4, ATP1A3, and ATP1A4 genes. We identified known mutations and some potentially pathogenic variants in each of these genes in specific cases, suggesting that their screening improves molecular diagnosis for the disorder. However, the majority of HM patients were found not to have candidate mutations in any of the previously reported HM genes, suggesting that additional genetic factors contributing to the disorder are yet to be identified.

Migraine management.

Migraine causes significant lost time from everyday activities. Addressing lifestyle triggers and comorbidities in patients with migraine is the first step of management Acute migraine treatments primarily manage the headache component and should be started as early as possible in the migraine attack Prophylaxis may be recommended if a patient is having three or more migraines a month or if their migraines are difficult to manage The choice of prophylactic drugs should be tailored to the individual's potential for adverse effects, interactions and comorbidities

Erenumab in Chronic Migraine: An Australian Experience.

OBJECTIVE: To determine the effectiveness and safety of erenumab in patients with chronic migraine in the real-world setting of 3 headache centers in Australia. METHODS: Patients with migraine were prescribed erenumab (70 or 140 mg) in the setting of either a product familiarization program or paid access to the medication in 3 headache centers in Australia. We obtained baseline and monthly prospective data on monthly headache days, monthly migraine days, monthly triptan use days, monthly codeine use days, Headache Impact Test-6 scores, and adverse reactions. In this paper, we present our data at 3 and 6 months in our subgroup of patients with chronic migraine with and without medication overuse. RESULTS: A total of 170 patients with chronic migraine were prescribed erenumab in the 3 headache centers. At 3 months, 100/170 (58.8%) had 50% or greater reduction in monthly migraine days. At 6 months, 79/170 (46.5%) had 50% or greater reduction in monthly migraine days. At 6 months, there was a mean reduction in monthly headache days of 9.2 days, a mean reduction in monthly migraine days of 10.2 days. There were few adverse events reported. CONCLUSION: This is the first report from 3 Australian headache centers about erenumab in the real world. Our analysis has supported erenumab as an effective and well-tolerated migraine preventative therapy for patients with chronic migraine who have failed many preventative therapies.

Migraine Aura: Pathophysiology, Mimics, and Treatment Options.

Recent insights into the clinical presentation and pathophysiology of migraine aura have paved the way for new treatments for this common but frequently debilitating condition. Marked efflux of cellular potassium and glutamate contributes to the cortical spreading depression that forms the electrophysiological basis of migraine aura phenomena. Secondary vascular perturbations also contribute to the various symptoms of a migraine attack. Calcitonin gene-related peptide (CGRP) plays a key role in many of these steps, and a growing class of CGRP-antagonists have emerged as a novel, efficacious preventative therapy. It is still not fully understood why a preponderance of migraine aura symptoms is visual, and this issue is an active area of research. In addition, the pathophysiological changes responsible for visual snow syndrome are under investigation. Before diagnosing a patient with migraine aura, it is important to consider the differential diagnosis of transient visual phenomena, with attention to clinical features that may suggest conditions such as retinal disorders, transient ischemic attack, or occipital epilepsy.

Canagliflozin and Stroke in Type 2 Diabetes Mellitus.

Background and Purpose- This study reports the detailed effects of canagliflozin on stroke, stroke subtypes, and vascular outcomes in participants with and without cerebrovascular disease (stroke or transient ischemic attack) at baseline from the CANVAS (Canagliflozin Cardiovascular Assessment Study) Program. Methods- The CANVAS Program, comprising 2 similarly designed and conducted clinical trials, randomly assigned 10 142 participants with type 2 diabetes mellitus and high cardiovascular risk to canagliflozin or placebo. Its primary outcome was a composite of major adverse cardiovascular events. The main outcome of interest for this report was fatal or nonfatal stroke. Additional exploratory outcomes were stroke subtypes and other vascular outcomes defined according to standard criteria. Results- There were 1 958 (19%) participants with prior stroke or transient ischemic attack at baseline. These individuals were older, more frequently women, and had higher rates of heart failure, atrial fibrillation, and microvascular disease (all P<0.001) compared with those without such a history. There were 309 participants with stroke events during follow-up (123 had prior stroke or transient ischemic attack at baseline and 186 did not), at a rate of 7.93/1000 patient-years among those assigned canagliflozin and 9.62/1000 patient-years among placebo (hazard ratio, 0.87; 95% CI, 0.69-1.09). Analysis of stroke subtypes found no effect on ischemic stroke (n=253, hazard ratio, 0.95; 95% CI, 0.74-1.22), a significant reduction for hemorrhagic stroke (n=30, hazard ratio, 0.43; 95% CI, 0.20-0.89) and no effect on undetermined stroke (n=29, hazard ratio, 1.04; 95% CI, 0.48-2.22). Effects on other cardiovascular outcomes were comparable among participants with and without stroke or transient ischemic attack at baseline. Conclusions- There were too few events in the CANVAS Program to separately define the effects of canagliflozin on stroke, but benefit is more likely than harm. The observed possible protective effect for hemorrhagic stroke was based on small numbers but warrants further investigation. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01032629 and NCT01989754.

Clinical nurses' knowledge of evidence-based practice: constructing a framework to evaluate a multifaceted intervention for implementing EBP.

Critical reflection upon nursing practice is pivotal in achieving optimal patient outcomes. Implicit in this statement is knowledge about and an understanding of the implementation of evidence-based practice (EBP). This study sought to evaluate baseline knowledge in order to assess and inform a multifaceted intervention to promote EBP in a multi-site facility in Western Sydney, Australia. On two consecutive days in February 2003, a convenience sample of 229 nurses were surveyed using a five-item, investigator developed, written survey tool. Data were analysed using descriptive statistics. Although the majority of respondents (n = 143: 62%) stated that they were aware of EBP, a considerable number (n = 86: 38%) stated they had not previously heard of the term. Of concern, 43% (n = 99) of respondents were unable to identify a source of information and resources about EBP. The results of this observational, descriptive survey underscore the importance of ongoing strategic interventions to improve knowledge, access and implementation of EBP amongst clinical nurses. This study also provides baseline data upon which to evaluate local interventions to promote knowledge of EBP amongst clinicians.