GAN-MAT: Generative adversarial network-based microstructural profile covariance analysis toolbox.

Multimodal magnetic resonance imaging (MRI) provides complementary information for investigating brain structure and function; for example, an in vivo microstructure-sensitive proxy can be estimated using the ratio between T1- and T2-weighted structural MRI. However, acquiring multiple imaging modalities is challenging in patients with inattentive disorders. In this study, we proposed a comprehensive framework to provide multiple imaging features related to the brain microstructure using only T1-weighted MRI. Our toolbox consists of (i) synthesizing T2-weighted MRI from T1-weighted MRI using a conditional generative adversarial network; (ii) estimating microstructural features, including intracortical covariance and moment features of cortical layer-wise microstructural profiles; and (iii) generating a microstructural gradient, which is a low-dimensional representation of the intracortical microstructure profile. We trained and tested our toolbox using T1- and T2-weighted MRI scans of 1,104 healthy young adults obtained from the Human Connectome Project database. We found that the synthesized T2-weighted MRI was very similar to the actual image and that the synthesized data successfully reproduced the microstructural features. The toolbox was validated using an independent dataset containing healthy controls and patients with episodic migraine as well as the atypical developmental condition of autism spectrum disorder. Our toolbox may provide a new paradigm for analyzing multimodal structural MRI in the neuroscience community and is openly accessible at https://github.com/CAMIN-neuro/GAN-MAT.

International Headache Society global practice recommendations for the acute pharmacological treatment of migraine.

BACKGROUND: In an effort to improve migraine management around the world, the International Headache Society (IHS) has here developed a list of practical recommendations for the acute pharmacological treatment of migraine. The recommendations are categorized into optimal and essential, in order to provide treatment options for all possible settings, including those with limited access to migraine medications. METHODS: An IHS steering committee developed a list of clinical questions based on practical issues in the management of migraine. A selected group of international senior and junior headache experts developed the recommendations, following expert consensus and the review of available national and international headache guidelines and guidance documents. Following the initial search, a bibliography of twenty-one national and international guidelines was created and reviewed by the working group. RESULTS: A total of seventeen questions addressing different aspects of acute migraine treatment have been outlined. For each of them we provide an optimal recommendation, to be used whenever possible, and an essential recommendation to be used when the optimal level cannot be attained. CONCLUSION: Adoption of these international recommendations will improve the quality of acute migraine treatment around the world, even where pharmacological options remain limited.

Effect of prednisolone for the treatment of medication-overuse headache: A 3-month result from a multicenter REgistry for Load and management of mEdicAtion overuSE headache (RELEASE) study.

OBJECTIVE: To evaluate the efficacy of prednisolone in the treatment of medication-overuse headache (MOH) using data from a multicenter prospective registry (Registry for Load and Management of Medication Overuse Headache [RELEASE]). BACKGROUND: The treatment of MOH is challenging, especially when withdrawal headache manifests during the cessation of overused medication. Although systemic corticosteroids have been empirically used to reduce withdrawal headaches, their efficacy on the long-term outcomes of MOH has not been documented. METHODS: This was a post hoc analysis of the RELEASE study. The RELEASE is an ongoing multicenter observational cohort study in which patients with MOH have been recruited from seven hospitals in Korea since April 2020. Clinical characteristics, disease profiles, treatments, and outcomes were assessed at baseline and specific time points. We analyzed the effect of prednisolone on MOH reversal at 3 months. RESULTS: Among the 309 patients enrolled during the study period, prednisolone was prescribed to 59/309 (19.1%) patients at a dose ranging from 10 to 40 mg/day for 5-14 days; 228/309 patients (73.8%) completed the 3-month follow-up period. The MOH reversal rates at 3 months after baseline were 76% (31/41) in the prednisolone group and 57.8% (108/187) in the non-prednisolone group (p = 0.034). The effect of steroids remained significant (adjusted odds ratio 2.78, 95% confidence interval 1.27-6.1, p = 0.010) after adjusting for the number of monthly headache days at baseline, mode of discontinuation of overused medication, use of early preventive medications, and the number of preventive medications combined. CONCLUSIONS: Although our observational study could not draw a definitive conclusion, prednisolone may be effective in the treatment of MOH.

Shifts in structural connectome organization in the limbic and sensory systems of patients with episodic migraine.

Migraine is a complex neurological condition characterized by recurrent headaches, which is often accompanied by various neurological symptoms. Magnetic resonance imaging (MRI) is a powerful tool for investigating whole-brain connectivity patterns; however, systematic assessment of structural connectome organization has rarely been performed. In the present study, we aimed to examine the changes in structural connectivity in patients with episodic migraines using diffusion MRI. First, we computed structural connectivity using diffusion MRI tractography, after which we applied dimensionality reduction techniques to the structural connectivity and generated three low-dimensional eigenvectors. We subsequently calculated the manifold eccentricity, defined as the Euclidean distance between each data point and the center of the data in the manifold space. We then compared the manifold eccentricity between patients with migraines and healthy controls, revealing significant between-group differences in the orbitofrontal cortex, temporal pole, and sensory/motor regions. Between-group differences in subcortico-cortical connectivity further revealed significant changes in the amygdala, accumbens, and caudate nuclei. Finally, supervised machine learning effectively classified patients with migraines and healthy controls using cortical and subcortical structural connectivity features, highlighting the importance of the orbitofrontal and sensory cortices, in addition to the caudate, in distinguishing between the groups. Our findings confirmed that episodic migraine is related to the structural connectome changes in the limbic and sensory systems, suggesting its potential utility as a diagnostic marker for migraine.

Clinical profile and treatment outcomes of idiopathic intracranial hypertension: a multicenter study from Korea.

BACKGROUND: Currently, there is a relative lack of detailed reports regarding clinical presentation and outcome of idiopathic intracranial hypertension in Asians. This study aims to describe the clinical features and treatment outcomes of Korean patients with idiopathic intracranial hypertension. METHODS: We prospectively recruited patients with idiopathic intracranial hypertension from one hospital and retrospectively analyzed the medical records of 11 hospitals in Korea. We collected data regarding preceding medical conditions or suspected medication exposure, headache phenotypes, other associated symptoms, detailed neuroimaging findings, treatments, and outcomes after 1-2 and 3-6 months of treatment. RESULTS: Fifty-nine (83.1% women) patients were included. The mean body mass index was 29.11 (standard deviation, 5.87) kg/m2; only 27 patients (45.8%) had a body mass index of ≥ 30 kg/m2. Fifty-one (86.4%) patients experienced headaches, patterns of which included chronic migraine (15/51 [29.4%]), episodic migraine (8/51 [15.7%]), probable migraine (4/51 [7.8%]), chronic tension-type headache (3/51 [5.9%]), episodic tension-type headache (2/51 [3.9%]), probable tension-type headache (2/51 [3.9%]), and unclassified (17/51 [33.3%]). Medication overuse headache was diagnosed in 4/51 (7.8%) patients. After 3-6 months of treatment, the intracranial pressure normalized in 8/32 (25.0%), improved in 17/32 (53.1%), no changed in 7/32 (21.9%), and worsened in none. Over the same period, headaches remitted or significantly improved by more than 50% in 24/39 patients (61.5%), improved less than 50% in 9/39 (23.1%), and persisted or worsened in 6/39 (15.4%) patients. CONCLUSION: Our findings suggest that the features of Asian patients with idiopathic intracranial hypertension may be atypical (i.e., less likely obese, less female predominance). A wide spectrum of headache phenotypes was observed. Medical treatment resulted in overall favorable short-term outcomes; however, the headaches did not improve in a small proportion of patients.

Whole-brain functional gradients reveal cortical and subcortical alterations in patients with episodic migraine.

Migraine is a type of headache with multiple neurological symptoms. Prior neuroimaging studies in patients with migraine based on functional magnetic resonance imaging have found regional as well as network-level alterations in brain function. Here, we expand on prior studies by establishing whole-brain functional connectivity patterns in patients with migraine using dimensionality reduction techniques. We studied functional brain connectivity in 50 patients with episodic migraine and sex- and age-matched healthy controls. Using dimensionality reduction techniques that project high-dimensional functional connectivity onto low-dimensional representations (i.e., eigenvectors), we found significant between-group differences in the eigenvectors between patients with migraine and healthy controls, particularly in the sensory/motor and limbic cortices. Furthermore, we assessed between-group differences in subcortical connectivity with subcortical weighted manifolds defined by subcortico-cortical connectivity multiplied by cortical eigenvectors and revealed significant alterations in the amygdala. Finally, leveraging supervised machine learning, we moderately predicted headache frequency using cortical and subcortical functional connectivity features, again indicating that sensory and limbic regions play a particularly important role in predicting migraine frequency. Our study confirmed that migraine is a hierarchical disease of the brain that shows alterations along the sensory-limbic axis, and therefore, the functional connectivity in these areas could be a useful marker to investigate migraine symptomatology.

Epicranial headache part 1: Primary stabbing headache.

BACKGROUND/OBJECTIVE: Primary stabbing headache is a common but under-recognized primary headache disorder. The objectives of this review were to provide practical information for better understanding and identification of the disease, suggest an algorithm for differential diagnosis, and provide an insight into the pathophysiology of primary stabbing headache hypothesized from its clinical course. METHODS: This narrative review of primary stabbing headache is based on a literature search and the authors' clinical reasoning. RESULT: The phenotype of each stab is typically abrupt, ultrashort-lasting (<3 s), focal or multifocal, paroxysms of pain occurring sporadically or in clusters. The diagnosis of primary stabbing headache is clinical; fixed or migrating stabs without background pain or sensory abnormalities and the absence of features suggestive of other disorders (e.g., cranial autonomic symptoms or signs) can aid in the diagnosis of primary stabbing headache. The clinical patterns include monophasic, intermittent, and chronic primary stabbing headache, of which the first two are considered typical. The pathophysiology of primary stabbing headache has not yet been elucidated. In this review, we postulated the mechanism of stabbing headache, based on the pain phenotype and clinical course, and provide a clinical algorithm for the differential diagnosis of primary stabbing headache. CONCLUSION: Knowledge about the typical manifestations and clinical patterns of primary stabbing headache will aid in the proper diagnosis and differential diagnosis. Treatment should be tailored by considering the clinical patterns. Further research is needed to elucidate the pathophysiological mechanisms and optimal treatment of primary stabbing headache.

New migraine prophylactic drugs: Current evidence and practical suggestions for non-responders to prior therapy.

BACKGROUND: Monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor (anti-CGRP(-R) mAbs) and small-molecule CGRP receptor antagonists (gepants) are new mechanism-based prophylactic drugs developed to address the unmet needs of pre-existing migraine prophylactic medications. However, several uncertainties remain in their real-world applications. METHODS: This is a narrative review of the literature on the use of CGRP-targeting novel therapeutics in specific situations, including non-responders to prior therapy, combination therapy, switching, and treatment termination. In the case of lack of available literature, we made suggestions based on clinical reasoning. RESULTS: High-quality evidence supports the use of all available anti-CGRP(-R) mAbs (erenumab, galcanezumab, fremanezumab, and eptinezumab) in non-responders to prior therapy. There is insufficient evidence to support or reject the efficacy of combining CGRP(-R) mAbs or gepants with oral migraine prophylactic agents or botulinum toxin A. Switching from one CGRP(-R) mAb to another might benefit a fraction of patients. Currently, treatment termination depends on reimbursement policies, and the optimal mode of termination is discussed. CONCLUSIONS: New prophylactic drugs that target the CGRP pathway are promising treatment options for patients with difficult-to-treat migraine. Individualized approaches using a combination of new substances with oral prophylactic drugs or botulinum toxin A, switching between new drugs, and adjusting treatment duration could enhance excellence in practice.

Epidemiology, burden and clinical spectrum of cluster headache: a global update.

BACKGROUND: This narrative review aims to broaden our understanding of the epidemiology, burden and clinical spectrum of cluster headache based on updated findings with a global perspective. METHODS: We conducted a literature search on the following topics: (a) epidemiology; (b) burden: quality of life, disability, economic burden, job-related burden and suicidality; and (c) clinical spectrum: male predominance and its changes, age, pre-cluster and pre-attack symptoms, aura, post-drome, attack characteristics (location, severity, duration and associated symptoms), bout characteristics (attack frequency, bout duration and bout frequency), circadian and seasonal rhythmicity and disease course. RESULTS: New large-scale population-based reports have suggested a lower prevalence than previous estimations. The impact of cluster headache creates a significant burden in terms of the quality of life, disability, economic and job-related burdens and suicidality. Several studies have reported decreasing male-to-female ratios and a wide age range at disease onset. The non-headache phases of cluster headache, including pre-cluster, pre-attack and postictal symptoms, have recently been revisited. The latest data regarding attack characteristics, bout characteristics, and circadian and seasonal rhythmicity from different countries have shown variability among bouts, attacks, individuals and ethnicities. Studies on the disease course of cluster headache have shown typical characteristics of attacks or bouts that decrease with time. CONCLUSIONS: Cluster headache may be more than a "trigeminal autonomic headache" because it involves complex central nervous system phenomena. The spectrum of attacks and bouts is wider than previously recognised. Cluster headache is a dynamic disorder that evolves or regresses over time.

Efficacy and safety of monoclonal antibodies targeting CGRP in migraine prevention. GRADE tables elaborated by the ad hoc working group of the International Headache Society.

OBJECTIVES: Grading of Recommendations, Assessment Development and Evaluation (GRADE) tables were created using a standardized and independent assessment of the efficacy and side effects of treatments with monoclonal antibodies (mAb) against calcitonin gene-related peptide (CGRP) or the CGRP receptor for the prevention of migraine. We hope to provide support for author groups writing national or regional treatment or management guidelines for migraine prevention. METHODS: We formulated patient/population, intervention, comparison and outcomes (PICO) questions for the efficacy and safety of mAb against CGRP or the CGRP-receptor for the prevention of migraine attacks. We performed a systematic literature research for randomized studies with eptinezumab, erenumab, fremanezumab and galcanezumab and a pooled analysis was done, using RevMan 5.4 software. For dichotomous outcomes we used risk ratio, and for continuous outcomes we used the mean difference to compare and summarize the evidence between groups. The evidence across studies, for each outcome, except serious adverse events, was assessed using GRADE evidence tables. Additionally, we report the serious adverse effects in the tables of the characteristics of the studies. RESULTS: All mAb are superior to placebo for the reduction in monthly migraine days (days in which a headache consistent with migraine occurred) in participants with episodic and chronic migraine. There are no major differences between the mAb. CONCLUSIONS: The GRADE evidence summary tables provided will support author groups to write treatment guidelines for the prevention of migraine with mAb.

Outcome of epidural blood patch for imaging-negative spontaneous intracranial hypotension.

BACKGROUND: Spontaneous intracranial hypotension is diagnosed by an abnormal finding in brain MRI, spinal imaging, or lumbar puncture. However, the sensitivity of each test is low. We investigated whether patients with suspected spontaneous intracranial hypotension and negative imaging findings would respond to epidural blood patch. METHODS: We prospectively recruited patients with new-onset orthostatic headache admitted at the Samsung Medical Center from January 2017 to July 2021. In patients without abnormal imaging findings and no history of prior epidural blood patch, treatment outcome-defined as both 50% response in maximal headache intensity and improvement of orthostatic component-was collected at discharge and three months after epidural blood patch. RESULTS: We included 21 treatment-naïve patients with orthostatic headache and negative brain and spinal imaging results who received epidural blood patch. After epidural blood patch (mean 1.3 times, range 1-3), 14 (66.7%) and 19 (90.5%) patients achieved both 50% response and improvement of orthostatic component at discharge and three months post-treatment, respectively. Additionally, complete remission was reported in 11 (52.4%) patients at three-month follow-up, while most of the remaining patients had only mild headaches. Among nine (42.9%) patients who underwent lumbar puncture, none had an abnormally low opening pressure (median 13.8 cm H2O, range 9.2-21.5). CONCLUSION: Given the high responder rates of epidural blood patch in our study, empirical epidural blood patch should be considered to treat new-onset orthostatic headache, even when brain and spinal imaging are negative. The necessity of lumbar puncture is questionable considering the high response rate of epidural blood patch and low rate of "low pressure."

Treatment pattern and response for cluster headache in Korea: A prospective multicenter observation study.

BACKGROUND: Only limited data are available regarding the treatment status and response to cluster headache in an Asian population. Therefore, this study aimed to provide a real-world treatment pattern of cluster headache and the response rate of each treatment in an Asian population. METHODS: Patients with cluster headache were recruited between September 2016 and January 2019 from 16 hospitals in Korea. At the baseline visit, we surveyed the patients about their previous experience of cluster headache treatment, and acute and/or preventive treatments were prescribed at the physician's discretion. Treatment response was prospectively evaluated using a structured case-report form at 2 ± 2 weeks after baseline visit and reassessed after three months. RESULTS: Among 295 recruited patients, 262 experiencing active bouts were included. Only one-third of patients reported a previous experience of evidence-based treatment. At the baseline visit, oral triptans (73.4%), verapamil (68.3%), and systemic steroids (55.6%) were the three most common treatments prescribed by the investigators. Most treatments were given as combination. For acute treatment, oral triptans and oxygen were effective in 90.1% and 86.8% of the patients, respectively; for preventive treatment, evidence-based treatments, i.e. monotherapy or different combinations of verapamil, lithium, systemic steroids, and suboccipital steroid injection, helped 75.0% to 91.8% of patients. CONCLUSION: Our data provide the first prospective analysis of treatment responses in an Asian population with cluster headache. The patients responded well to treatment despite the limited availability of treatment options, and this might be attributed at least in part by combination of medications. Most patients were previously undertreated, suggesting a need to raise awareness of cluster headache among primary physicians.

Migraine: integrated approaches to clinical management and emerging treatments.

Migraine is a highly disabling neurological disorder that directly affects more than 1 billion individuals worldwide. Available treatment options differ between countries and include acute, preventive, and non-pharmacological therapies. Because of major progress in the understanding of migraine pathogenesis, novel mechanism-based medications have emerged and expanded the armamentarium of treatments. We provide a comprehensive overview of the current standard of care that will enable informed clinical management. First, we discuss the efficacy, tolerability, and safety profile of various pharmacological therapies for acute and preventive treatment of migraine. Second, we review the current knowledge on non-pharmacological therapies, such as neuromodulation and biobehavioural approaches, which can be used for a multidisciplinary approach to clinical management. Third, we emphasise that any effective treatment strategy starts with building a therapeutic plan tailored to individual clinical characteristics, preferences, and needs. Finally, we explore the outlook of emerging mechanism-based treatments that could address unmet challenges in clinical management of migraine.

Migraine: disease characterisation, biomarkers, and precision medicine.

Migraine is a disabling neurological disorder, diagnosis of which is based on clinical criteria. A shortcoming of these criteria is that they do not fully capture the heterogeneity of migraine, including the underlying genetic and neurobiological factors. This complexity has generated momentum for biomarker research to improve disease characterisation and identify novel drug targets. In this Series paper, we present the progress that has been made in the search for biomarkers of migraine within genetics, provocation modelling, biochemistry, and neuroimaging research. Additionally, we outline challenges and future directions for each biomarker modality. We also discuss the advances made in combining and integrating data from multiple biomarker modalities. These efforts contribute to developing precision medicine that can be applied to future patients with migraine.

Real-world efficacy of galcanezumab for the treatment of migraine in Korean patients.

BACKGROUND AND OBJECTIVE: We aimed to provide real-world data on the effectiveness of an anti-calcitonin gene-related peptide monoclonal antibody administered for treating migraine in Korean patients. METHODS: We prospectively recruited patients with migraine who received galcanezumab treatment at a single university hospital from June 2020 to April 2021. The treatment response was assessed after three consecutive monthly injections. A 50% responder rate was evaluated based on ≥50% reduction in the number of moderate/severe headache days. RESULTS: Overall, 87 patients were included in the analysis. Most patients were women (83.9%). They had a mean age of 41.7 ± 12.3 years (range 17-72). Sixty-five patients (74.7%) had chronic migraine, 35 patients (40.2%) had a history of medication-overuse headache, and 32 patients (36.8%) were previously unresponsive to or found intolerable five classes of preventive medication. After three months of treatment, mean changes in numbers of monthly headache days, moderate/severe headache days, crystal clear days, and days of acute medication use were -7.2 ± 8.43, -4.3 ± 9.76, 7.3 ± 8.50, and -4.1 ± 7.93, respectively. The 50% responder rates were 58.3%, 44.2%, and 40.6% for patients with unsuccessful previous use of 0-1, 2-4, and 5 preventive medication classes, respectively. Headache Impact Test-6 and Migraine Disability Assessment Test scores also decreased (-4.4 ± 8.09 and -32.9 ± 77.04, respectively). CONCLUSION: In our cohort, the effectiveness and safety of galcanezumab were comparable with those reported in clinical trials, whereas a higher response rate was observed in the difficult-to-treat patient subset than that reported in trials. We provide real-world evidence of galcanezumab treatment benefits in Asian patients with migraine.

Interim analysis of the Registry for Load and Management of Medication Overuse Headache (RELEASE): A multicenter, comprehensive medication overuse headache registry.

BACKGROUND: Characteristics, disabilities, and optimal management of medication overuse headache remain uncertain. This study aimed to elucidate the clinical characteristics of patients with medication overuse headache enrolled in a medication overuse headache registry in Korea. METHODS: The Registry for Load and Management of MEdicAtion OveruSE Headache (RELEASE), a cross-sectional prospective observational study including seven referral headache centers in Korea, started enrolling adult patients with medication overuse headache in April 2020. Data included information on headache characteristics, burden on daily function, depression, anxiety, history of acute and preventive medications, and treatment strategies. RESULTS: A total of 229 patients (85.6% females; mean age, 45.5 ± 13.5 years) were enrolled by June 2021. The average durations of chronic headaches and medication overuse were 6.5 and 4.3 years, respectively. In the past month before enrollment, patients had headaches for 25 days and severe headaches for 12 days, and used acute medications for 20 days. Patients were disabled in 66.8 days in the past 3 months and had moderate/severe depression and anxiety in 56% and 35%, respectively. The proportion of patients on preventive treatments increased from 38% to 93% during the study period. CONCLUSIONS: RELEASE study reflects the current management status and opportunities to improve the quality of care in patients with medication overuse headache.

Characteristics of pre-cluster symptoms in cluster headache: A cross-sectional multicentre study.

BACKGROUND: Contrary to pre-attack symptoms before an individual cluster headache attack, little is known about the pre-cluster symptoms before the onset of cluster bouts. We previously described pre-attack symptoms before cluster headache attacks. The aim of this study was to investigate characteristics of pre-cluster symptoms in patients with episodic cluster headache. METHODS: In this multicentre study, 184 patients with episodic cluster headache were recruited between October 2018 and December 2020. They were interviewed by investigators and completed a structured questionnaire. To investigate pre-cluster and pre-attack symptoms, we assessed 20 symptoms and signs using the questionnaire. RESULTS: The upcoming cluster bout was predictable in 35.3% (n = 65/184) of the patients. When present, pre-cluster symptoms occurred at a median duration of 7 days (interquartile range, 2.3-14 days) before the onset of the cluster bout. Patients with pre-cluster symptoms showed a higher proportion of women, prevalence of pre-attack symptoms and seasonal rhythmicity, frequency of cluster headache attacks per day, and total number of cluster bouts compared to patients without pre-cluster symptoms. In univariable and multivariable logistic regression analyses, female sex was associated with the predictability of pre-cluster symptoms (odds ratio = 2.297, p = 0.016). CONCLUSIONS: The upcoming cluster bout was predicted in approximately 35% of patients with episodic cluster headache, which may allow for an earlier preventive treatment and help understand the pathophysiology.

Effect of caffeine and caffeine cessation on cerebrovascular reactivity in patients with migraine.

OBJECTIVE: To investigate the effect of chronic caffeine use and caffeine cessation on vasodilatory function in the posterior circulation in patients with migraine. BACKGROUND: Studies regarding cerebrovascular reactivity (CVR) using vasodilatory stimuli in patients with migraine have yielded conflicting results. We postulated that CVR may not be static, and caffeine might negatively affect vasodilatory function via its vasoconstrictive effect. METHODS: In this prospective longitudinal observation study, we recruited patients with episodic migraine who were 18-50 years of age and free of vascular risk factors at the Samsung Medical Center between August 2015 and March 2020. Patients were classified into caffeine users and non-users at baseline, and caffeine users were instructed to discontinue caffeine intake. We measured the mean breath-holding index (BHI) of bilateral posterior cerebral arteries (PCA) using transcranial Doppler in all the included patients at baseline and followed up after 3 months. We compared breath-holding indices cross-sectionally between caffeine users and non-users and analyzed BHI changes according to caffeine cessation. RESULTS: In total, 84 patients completed the study protocol. Cross-sectional analysis showed that the baseline BHI of PCA was lower in caffeine users (n = 56, 1.1 [interquartile range (IQR) 0.8-1.3]) than that in nonusers (n = 28, 1.3 [IQR 1.0-1.5], p = 0.030). In the longitudinal analysis, caffeine quitters showed a significant improvement in BHI in PCA (baseline 1.1 [IQR 0.8-1.2], follow-up 1.3 [IQR 1.0-1.4], p = 0.034), whereas continuous users and non-users did not. Multivariable analysis showed an independent effect of caffeine cessation on the changes in BHI of PCA (unstandardized ß = 0.27, 95% confidence interval 0.01-0.53, p = 0.044). CONCLUSION: In patients with migraine, caffeine use is associated with reduced CVR in the posterior circulation, and caffeine cessation might be beneficial in improving CVR.

Clinical characteristics of medication-overuse headache according to the class of acute medication: A cross-sectional multicenter study.

OBJECTIVE: To characterize the clinical features of patients with medication-overuse headache (MOH) according to the class of acute medications being overused. BACKGROUND: MOH is a common global health problem, severely disabling the majority of the patients affected. Although various medications can cause MOH, whether clinical features differ according to the overused medication type remains unclear. METHODS: We analyzed data from a multicenter cross-sectional study in neurology clinics in Korea from April 2020 to June 2021. RESULTS: Among 229 eligible patients, MOH was documented in patients who overused multiple drug classes (69/229, 30.1%; most frequent occurrence), triptans (50/229, 21.8%), non-opioid analgesics (48/229, 21.0%), and combination-analgesics (40/229, 17.4%). Patients who overused multiple drug classes reported more frequent use of acute medications (median [25th-75th percentiles]: 25.0 [15.0-30.0] vs. 17.5 [10.0-25.5] days/month, p = 0.029) and fewer crystal-clear days (0.0 [0.0-9.5] vs. 9.0 [0.0-10.0] days/month, p = 0.048) than those who overused triptans. Patients who overused multiple drug classes also reported shorter intervals from chronic daily headache to the onset of MOH than patients who overused combination-analgesics (0.6 [0.2-1.9] vs. 2.4 [0.7-5.4] years, p = 0.001) or non-opioid analgesics (1.5 [0.6-4.3] years, p = 0.004). Patients who overused multiple drug classes reported more emergency room visits (1.0 [0.0-1.0] visits/year) than those who overused combination-analgesics (0.0 [0.0-1.0], p = 0.024) or non-opioid analgesics (0.0 [0.0-1.0], p = 0.030). Patients who overused triptans reported fewer headache days (21.0 [20.0-30.0] vs. 30.0 [20.5-30.0] days/month, p = 0.008) and fewer severe headache days (7.0 [4.0-10.0] vs. 10.0 [5.0-15.0] days/month, p = 0.017) than those who overused non-opioid analgesics. CONCLUSIONS: Some clinical characteristics of MOH significantly differed according to the class of overused medications. The findings from this study may contribute to the understanding of the clinical characteristics and pathophysiology of MOH.

Clinical characteristics of pre-attack symptoms in cluster headache: A large series of Korean patients.

BACKGROUND: Previous studies have reported notable differences in demographic and clinical features of cluster headache between Western and Asian populations, including lower prevalence of the chronic type and in women. Recently, prodromal symptoms of migraine and pre-attack symptoms of cluster headache have drawn attention regarding their potential pathophysiological implications and pre-emptive treatment. However, pre-attack symptoms of cluster headache have not been studied in the Asian population. METHODS: A total of 136 patients with cluster headache (21 first-onset, 110 episodic, and five chronic cases) were recruited in this multi-center study between October 2018 and December 2019. We evaluated the characteristics of pre-attack symptoms in a current bout using a structured questionnaire. Univariable and multivariable logistic regression analyses were performed to evaluate the factors associated with presence of pre-attack symptoms. RESULTS: Pre-attack symptoms were reported in 71.3% of our patients with cluster headache. When present, pre-attack symptoms occurred at a median of 20 minutes (range 1-120) before the attack. The prevalence of local and painful, local and painless sensory, autonomic, and general symptoms was 58.8%, 14.7%, 11.0%, and 30.1%, respectively. Multivariable logistic regression analysis revealed that higher number of bouts was associated with higher prevalence of pre-attack symptoms (OR = 1.464, p = 0.044). CONCLUSIONS: Pre-attack symptoms were frequently observed in Korean patients with cluster headache, which was consistent with previous Western studies.