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.

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.”

Background: Varicose veins (VV) were once considered benign and common ailments; however, recent research suggests a potential link between VV and cardiovascular diseases or mortality. VV share common risk factors and pathophysiology with cardiovascular disease, potentially influencing the vascular system. Therefore, the authors aimed to investigate the association between VV and the incidence risk of atrial fibrillation (AF) using a population-based cohort. Methods: Our retrospective cohort study included 2 680 971 individuals who underwent examination through the Korean National Health Screening Service from 2010 to 2011. VV was defined by two or more claims with the International Classification of Diseases 10th Revision diagnostic codes: I83.0, I83.1, I83.2 (VV of lower extremities with ulcer or inflammation, severe VV), and I83.9 (asymptomatic VV of lower extremities, mild VV). The 1:3 propensity score matching (PSM) was used to assess the risk of newly developed AF, identified via insurance claims coded as I48. Results: The mean age of all participants was 48.5±14.2 years, with 51.4% being male. Among the population, 24 557 (0.91%) had VV, including 3684 (0.14%) of severe VV and 20 873 (0.77%) of mild VV. During a median follow-up of 10.06 years, 24 557 (0.92%) cases of AF occurred. Participants with VV exhibited an increased incidence risk of AF compared to those without it before (HR: 1.13, 95% CI: 1.06–1.21, P<0.001) and after PSM (HR: 1.17, 95% CI: 1.08–1.27, P<0.001). This positive association was consistently observed in severe VV both before (HR: 1.19, 95% CI [1.09–1.28], P=0.002) and after PSM (HR: 1.20, 95% CI [1.10–1.30], P=0.003) and mild VV also before (HR: 1.10, 95% CI [1.04–1.16], P=0.003) and after PSM (HR: 1.13, 95% CI [1.03–1.–20], P<0.001). Conclusions: These findings suggest that VV may be associated with an increased risk of AF. Hence, the presence of VV should be considered as an association factor for AF occurrence.

Background: Smoking is known to be a significant risk factor for various diseases. Migraine, a condition requiring careful lifestyle management, currently lacks specific guidelines advocating for smoking cessation as a preventive measure. Although cross-sectional studies have suggested a potential link between smoking and an increased risk of migraine, the findings have been inconsistent and conflicting. To date, there has been no longitudinal study which investigated the effect of smoking on the risk of migraine in a prospective setting. Objective: This longitudinal study aimed to investigate the impact of smoking on the incidence of migraine in women and examine the modifying effect of menopausal status. Methods: Using nationally representative National Health Insurance Service (NHIS) data, women aged ≥40 years who participated in national breast cancer screening in 2009 were followed-up until the end of 2019. Baseline data on smoking status (non-, ex-, and current smoker) as well as the duration and amount of cigarette smoking were collected. A Cox proportional hazards regression model was used to examine the independent effect of smoking on the risk of incident migraine after adjusting for demographics, comorbidities, and female reproductive factors. The results were stratified by menopausal status, and an interaction analysis (smoking × menopause) was performed. Results: In total, 1,827,129 women were included in the analysis. Women with a history of smoking exhibited a higher risk of developing migraine, compared with nonsmokers. Specifically, a higher risk of migraine was observed in women with past (adjusted hazard ratio [HR] 1.044, 95% CI 1.000-1.089) and current cigarette use (adjusted HR 1.050, 95% CI, 1.023-1.079) than in nonsmokers. The effect was greater in premenopausal women (adjusted HR 1.140, 95% CI, 1.108-1.172) than in postmenopausal women (adjusted HR 1.045, 95% CI 1.018-1.073; P<.001). The risk increased with an increased amount of smoking, with a greater association in premenopausal women (P<.001). Conclusions: Smoking increases the risk of migraine in women, with a dose-dependent relationship. Menopause modifies this effect. Our findings suggest that smoking is an important modifiable risk factor of migraine, with a higher impact in premenopausal women. The interaction between smoking and estrogen may increase the vulnerability of the migraine brain.

Purpose: Recent advances in imaging techniques have significantly enhanced the diagnosis of spontaneous intracranial hypotension (SIH). However, these developments have been reported mostly in Europe and the United States. This study aimed to evaluate the availability and utilization of diagnostic and treatment modalities for SIH in Asia, through a survey of regional headache specialists.Methods: A literature search was conducted using PubMed, and members of the Asian Regional Consortium for Headache were contacted. Participants completed a two-step survey evaluating the availability, accessibility, and frequency of SIH diagnostic and treatment methods in their countries and institutions. Descriptive statistics were used to analyze the data.Results: Twenty physicians from eight countries completed both rounds of the survey. Lumbar puncture, brain magnetic resonance imaging (MRI), and spinal MRI are widely available across Asia, but real-time imaging techniques—such as dynamic computed tomography myelography and digital subtraction myelography—that precisely localize cerebrospinal fluid leaks are less accessible. Blind or semi-targeted epidural blood patches (EBPs) are available at most centers, but are easily accessible in only about half of cases. Surgical interventions are rarely available.Conclusion: Most diagnostic methods for SIH are available in Asia, despite some regional disparities. The utilization of EBP and surgical interventions remains somewhat limited. This highlights the need for greater awareness and standardization of diagnostic methods in Asia.

Background . Acute sensorineural hearing loss (SNHL) is a rare development in the central nervous system (CNS) demyelinating diseases such as aquaporin‐4‐IgG‐positive neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody‐associated disease (MOGAD). Methods . We retrospectively reviewed consecutive patients with seropositive NMOSD or MOGAD in the CNS Inflammatory and Demyelinating Disease Registry at Samsung Medical Center from January 2015 to December 2020. After the medical chart review, the demographic data and the results of brain magnetic resonance imaging (MRI) and audiometry of patients with hearing loss were collected. Results . Five patients (NMOSD, n = 3; MOGAD, n = 2) were diagnosed with SNHL, two developed SNHL before the first core clinical symptom, and another two patients who underwent brain MRI at the timing of hearing loss showed lesions. Only three patients received high‐dose steroids; however, hearing loss did not improve in any patients. Conclusion . SNHL was observed in a small number of patients with seropositive NMOSD and MOGAD; however, it could be underrecognized. Further large cohort prospective studies are helpful to elucidate the clinical implication of SNHL in NMOSD and MOGAD.