Changes in migraine interictal burden following treatment with galcanezumab: Results from a phase III randomized, placebo-controlled study.

OBJECTIVE: To evaluate changes in interictal burden with galcanezumab versus placebo in patients with episodic (EM) or chronic migraine (CM). BACKGROUND: The disruptive effects of migraine occur both during attacks (ictal period) and between attacks (interictal period), affecting work, school, family, and social life. Migraine clinical trials typically assess ictal burden endpoints, neglecting interictal burden. METHODS: CONQUER was a 3-month, double-blind study that randomized adult patients with EM or CM who had experienced failure of two to four standard-of-care migraine preventive medication categories to receive monthly galcanezumab (n = 232) or placebo (n = 230), followed by 3 months of open-label galcanezumab. The mean change in interictal burden, a secondary objective, was measured using the four-item Migraine Interictal Burden Scale (MIBS-4). The total score for MIBS-4 can range from zero to 12, with scores ≥5 indicating severe interictal burden. Post hoc analyses evaluated shifts in MIBS-4 severity categories and item-level improvement. RESULTS: The MIBS-4 total score indicated severe interictal burden at baseline (mean [SD]: all patients, 5.5 [3.5]; EM, 5.0 [3.4]; CM, 6.2 [3.5]). Reductions in the MIBS-4 score were significantly greater with galcanezumab versus placebo at Month 3 (mean [SE]: all patients -1.9 [0.2] vs. -0.8 [0.2], p < 0.0001; EM, -1.8 [0.3] vs. -1.1 [0.3], p = 0.033; CM, -1.8 [0.4] vs. -0.3 [0.4], p < 0.001), with further improvement at Month 6 after all patients had received galcanezumab (mean [SE]: all patients, -2.4 [0.2] vs. -2.0 [0.2]; EM, -2.3 [0.3] vs. -2.2 [0.3]; CM, -2.1 [0.4] vs. -1.5 [0.4]). The percentage of patients with severe interictal burden decreased substantially for the galcanezumab-treated patients, from 59% (137/232) at baseline to 27% (58/217) at Month 6 (EM from 51% [70/137] to 23% [30/131]; CM from 71% [67/95] to 33% [28/86]). CONCLUSION: In addition to the known efficacy of galcanezumab in the ictal period, these findings suggest treatment with galcanezumab results in a significant reduction in interictal burden.

Real-World experience of interictal burden and treatment in migraine: a qualitative interview study.

BACKGROUND: The debilitating nature of migraine attacks is widely established; however, less is known about how the interictal burden (i.e., how patients are affected in-between migraine episodes) of migraine impacts on patients' health-related quality of life (HRQL). Acute and preventive treatments may lift the burden of the disease, but they often have unwanted side effects and limited effectiveness. The objective of this study was to understand the interictal burden of migraines, from the patient perspective, and to explore patient experience with migraine treatments. METHODS: Participants (n=35) with a self-reported diagnosis of migraine were recruited in the US, UK and Canada, including a subgroup of patients who had taken calcitonin gene-related peptide monoclonal antibody (CGRP mAb) treatment for at least three months. Participants completed a background questionnaire, followed by a semi-structured interview via telephone or video call. The interviews explored patients' migraine symptoms, perception of interictal burden and treatment experience. The interview transcripts were analysed using thematic analysis. RESULTS: The most reported migraine symptom was migraine pain, followed by aura, sensory sensitivity and nausea. Most participants reported interictal impact on HRQL, lifestyle changes they made to avoid triggers or in anticipation of an attack, impacts on work, career, daily activities and relationships. Emotional impacts were reported by all participants, including anger, depression, anxiety and hopelessness. Many participants who took preventive treatments reported improvements in HRQL and functioning but still experienced breakthrough attacks. Among patients who took CGRP mAbs, participants noted varying consistency of treatment effectiveness between treatment administrations. CONCLUSION: This study detailed the additional HRQL impact of migraine in-between migraine attacks and described the unmet need for effective treatment options to prevent and mitigate migraine attacks.

Interictal Burden of Cluster Headache: Results of the EUROLIGHT Cluster Headache Project, an Internet-Based, Cross-Sectional Study of People With Cluster Headache.

OBJECTIVE: The aim of this study was to measure the interictal burden (IIB) associated with cluster headache (CH). BACKGROUND: CH is characterized by an alternation of excruciatingly painful attacks and pain-free periods. Absence of pain does not necessarily imply absence of symptoms, though. Some may persist or improve more slowly than pain; others may arise in between attacks. METHODS: Participants filled out an online survey based on the EUROLIGHT questionnaire. Inclusion criteria were a reported diagnosis of CH and residency in a European country; exclusion criteria were refusal to give informed consent and to complete the questionnaire. RESULTS: Most of the burden was related to higher headache frequencies: ongoing symptoms despite pain freedom, impaired autonomy due to avoidance of triggers, reluctance to tell others about the disease, and the feeling of not being understood by family and friends, employers and colleagues. Irreversible, potentially accumulating burden may occur if headache frequency is high; examples are impairment of career options, relationships, and family planning issues. Worrying about future attacks and avoiding potential triggers occur independently from attack frequency and disease duration. There were no differences between the in-bout and the out-bout period among participants with episodic CH. Participants with chronic CH reported greater IIB. CONCLUSIONS: Even between attacks CH can have a huge and potentially irreversible impact on life. Different types of IIB were identified, all of which may contribute to the total burden of disease. As cumulative burden might be irreversible, prevention strategies need to be developed.

Interictal burden attributable to episodic headache: findings from the Eurolight project.

BACKGROUND: Most primary headaches are episodic, and most estimates of the heavy disability burden attributed to headache derive from epidemiological data focused on the episodic subtypes of migraine and tension-type headache (TTH). These disorders give rise directly but intermittently to symptom burden. Nevertheless, people with these disorders may not be symptom-free between attacks. We analysed the Eurolight dataset for interictal burden. METHODS: Eurolight was a cross-sectional survey using modified cluster sampling from the adult population (18-65 years) in 10 countries of the European Union. We used data from nine. The questionnaire included headache-diagnostic questions based on ICHD-II and several question sets addressing impact, including interictal and cumulative burdens. RESULTS: There were 6455 participants with headache (male 2444 [37.9 %]). Interictal symptoms were reported by 26.0 % of those with migraine and 18.9 % with TTH: interictal anxiety by 10.6 % with migraine and avoidance (lifestyle compromise) by 14.8 %, both much more common than in TTH (3.1 % [OR 3.8] and 4.7 % [OR 3.5] respectively). Mean time spent in the interictal state was 317 days/year for migraine, 331 days/year for TTH. Those who were "rarely" or "never" in control of their headaches (migraine 15.2 %, TTH 9.6 %) had significantly raised odds of interictal anxiety, avoidance and other interictal symptoms. Among those with migraine, interictal anxiety increased markedly with headache intensity and frequency, avoidance less so but still significantly. Lost productive time was associated with high ORs (up to 5.3) of anxiety and avoidance. A third (32.9 %) with migraine and a quarter (26.7 %) with TTH (difference: p < 0.0001) were reluctant to tell others of their headaches. About 10 % with each disorder felt families and friends did not understand their headaches. Nearly 12 % with migraine reported their employers and colleagues did not. Regarding cumulative burden, 11.8 % reported they had done less well in education because of headache, 5.9 % reported reduced earnings and 7.4 % that their careers had suffered. CONCLUSIONS: Interictal burden in those with episodic headache is common, more so in migraine than TTH. Some elements have the potential to be profoundly consequential. New methodology is needed to measure interictal burden if descriptions of headache burden are to be complete.

Effects of OnabotulinumtoxinA on Allodynia and Interictal Burden of Patients with Chronic Migraine.

BACKGROUND: We primarily aimed to ascertain whether treatment with OnabotulinumtoxinA (BoNTA) might influence the extent of the interictal burden and cutaneous allodynia in patients with chronic migraine (CM). METHODS: Seventy CM patients, who received three consecutive cycles of BoNTA, were studied. The interictal burden was assessed with the Migraine Interictal Burden Scale (MIBS-4), while cutaneous allodynia was examined with the Allodynia Symptom Checklist (ASC-12) together with PI-NRS VAS to obtain hair brushing scores, and then these were compared from baseline (T0) to the last efficacy evaluation follow-up (T1). Efficacy outcomes, mostly mean headache days (MHD) and "Headache Impact Test" scores, were also assessed between T0 and T1. RESULTS: BONTA improved the interictal burden, with a decrease in MIBS-4 scoring by an average of -7 at T1, compared to baseline (p < 0.001). The percentage of patients with a moderate/severe interictal burden was substantially decreased. Likewise, BoNTA reduced the extent of cutaneous allodynia, with a significant reduction in both the ASC-12 (1 vs. 6; p < 0.001) and PI-NRS VAS (1 vs. 5; p < 0.001) to hair brushing median scores at T1, compared to baseline. Reduced MHD rates were significantly associated with a smaller interictal burden at T1. The efficacy of BoNTA, with a significant reduction in MHD and HIT-6 scores at T1 compared to T0, was re-confirmed. CONCLUSIONS: BoNTA resulted in a statistically significant reduction in the interictal burden and also improved cutaneous allodynia. The reduction in ictal burden was associated with the down-scaling of the interictal burden. Hence, BoNTA improved the full spectrum of migraine impairment by diminishing the clinical expression of central sensitization.

Beyond Pain: The Effects of OnabotulinumtoxinA Therapy on Sensitization and Interictal Symptoms in Chronic Migraine.

Chronic migraine is a disease with a high burden on patients from both a working and quality of life point of view. The pathophysiology of this subtype of migraine is due to several factors, such as medication overuse. Nevertheless, the detrimental recurring of headache attacks with central and peripheral sensitization plays a central role and explains some additional symptoms complained about by these patients even in the interictal phase. OnabotulinumtoxinA is a therapy indicated for chronic migraine since it has proven to reduce peripheral sensitization, showing even efficacy on central symptoms. The aim of this narrative review is to present the current evidence regarding the effect of OnabotulinumtoxinA on sensitization and interictal symptoms.

Evaluating migraineurs' preferences for migraine treatment outcomes using a choice experiment.

OBJECTIVE: The impact of migraines on patients is commonly divided between the level of impairment associated with headache symptoms (headache phase) and the quality-of-life effects immediately following the headache (post-headache phase). Evaluations of migraineurs' productivity losses and health-related quality of life have provided an understanding of the burden associated with the headache and post-headache symptoms, but do not quantify the relative importance of each phase from a patient perspective. In this study, we evaluated migraineurs' willingness to accept trade-offs among symptom severity in the headache and post-headache phases, symptom duration in the headache and post-headache phases, and symptom-free time within a general-preference theoretic framework. METHODS: We administered a choice-format, conjoint-analysis survey, also called a discrete-choice experiment, to a sample of migraineurs from a nationally representative online consumer panel. After inclusion and exclusion criteria were applied, 510 eligible subjects completed the survey. The survey elicited choices between pairs of migraine profiles describing symptom durations and symptom-free time for the headache and post-headache phase. RESULTS: Migraineurs in our study were strongly affected by the pain associated with the headache phase. However, experiencing difficulty with daily social and family activities in the post-headache phase also had a statistically significant impact on migraineurs' perceived level of well-being. Migraineurs reported that hypothetical treatments that limited the duration of headache symptoms without allowing them to resume their daily activities for 16 hours after a headache, on average, were less than half as good as treatments that limited both headache and post-headache symptoms. CONCLUSION: Our results suggest that treatments that relieve and shorten symptoms during the post-headache phase can offer significant benefits to migraineurs.

Cluster Headache and the Comprehension Paradox.

Patients with primary headache disorders such as cluster headache cycle between being entirely healthy and almost completely incapacitated. Sick leave or reduced performance due to headache attacks demands flexibility by their social counterparts. The objective of this study is to test the hypothesis that headache patients cause frustration that grows with the times colleagues have to take over their work. In this study, we analysed cluster headache patients' answers to an online questionnaire. Participants self-reported their number of sick days, the number of days on which leisure activities were missed and whether they felt understood by colleagues and family. We then investigated the correlation between the number of sick days and the proportion of patients feeling understood by colleagues and friends. We found that feeling understood by colleagues and friends decreases with a growing number of sick days. However, when sick days accrue further, this proportion increases again. The number of sick days correlates similarly with both colleagues' and friends' understanding. The number of cluster headache patients feeling understood by others decreases with an increasing number of sick days. Their social circles' frustration with the patients' failure to meet obligations and expectations are a likely reason. With a growing number of sick days, however, the portion of patients feeling understood rises again despite patients meeting others' expectations even less. This 'comprehension paradox' implies the influence of other factors. We suspect that growing numbers of sick days foster understanding as the disability of the disease becomes increasingly apparent.

The not so hidden impact of interictal burden in migraine: A narrative review.

Migraine is a highly prevalent neurological disease of varying attack frequency. Headache attacks that are accompanied by a combination of impact on daily activities, photophobia and/or nausea are most commonly migraine. The headache phase of a migraine attack has attracted more research, assessment tools and treatment goals than any other feature, characteristic, or phase of migraine. However, the migraine attack may encompass up to 4 phases: the prodrome, aura, headache phase and postdrome. There is growing recognition that the burden of migraine, including symptoms associated with the headache phase of the attack, may persist between migraine attacks, sometimes referred to as the "interictal phase." These include allodynia, hypersensitivity, photophobia, phonophobia, osmophobia, visual/vestibular disturbances and motion sickness. Subtle interictal clinical manifestations and a patient's trepidation to make plans or commitments due to the unpredictability of migraine attacks may contribute to poorer quality of life. However, there are only a few tools available to assess the interictal burden. Herein, we examine the recent advances in the recognition, description, and assessment of the interictal burden of migraine. We also highlight the value in patients feeling comfortable discussing the symptoms and overall burden of migraine when discussing migraine treatment needs with their provider.