Clinical predictors of therapeutic failure of occipital nerve stimulation in refractory chronic cluster headache.

BACKGROUND: Occipital nerve stimulation (ONS) is a treatment with evidence in refractory chronic cluster headache (CCH). However, the variable response rate and cost make it necessary to investigate predictors of response. METHODS: This is a cross-sectional study conducted through the review of medical records of CCH patients from six hospitals in Madrid. Epidemiological and clinical variables were compared between patients with ONS failure and the rest. ONS failure was defined as the need for device withdrawal or switch off because of lack of response or adverse events. RESULTS: From a series of 88 CCH, 26 (29.6%) underwent ONS surgery, of whom 13/26 (50.0%) failed because lack of response. ONS failure group had an earlier headache onset (mean ± SD) of 27.7 ± 6.9 vs. 36.7 ± 11.8 years, p = 0.026) and a higher smoking rate (100% vs. 42.9%, p = 0.006). Stational fluctuations (58.3% vs. 7.7%, p = 0.007) and nocturnal exacerbations (91.7% vs. 53.9%, p = 0.035) were more frequent in the ONS failure group as well. There was no difference between groups in diagnostic delay, years of evolution prior to surgery, mental illness, comorbidity with other headache disorders or chronic pain conditions or prior response to occipital nerves anesthetic blocks. CONCLUSIONS: Some clinical features such as an early debut, smoking and seasonal or circadian fluctuations could be related to failure of ONS in refractory CCH.

CandeSpartan Study: Candesartan Spanish Response-prediction and Tolerability study in migraine.

INTRODUCTION: Effectiveness of candesartan in migraine prevention is supported by two randomized controlled trials. We aimed to assess the effectiveness, tolerability, and response predictors of candesartan in the preventive treatment of migraine. METHODS: Observational, multicenter, prospective cohort study. The 50%, 75% and 30% responder rates, between weeks 8-12 and 20-24, were compared with the baseline. Treatment emergent adverse effects were systematically evaluated. Response predictors were estimated by multivariate regression models. RESULTS: Eighty-six patients were included, 79.1% females, aged 39.5 (inter-quartile range [IQR] 26.3-50.3), with chronic migraine (43.0%), medication overuse headache (55.8%) and a median of two (inter-quartile range: 0.75-3) prior preventive treatments. At baseline patients had 14 (10-24) headache and 8 (5-11) migraine days per month. The 30%, 50% and 75% responder rates were 40%, 34.9% and 15.1% between weeks 8-12, and 48.8%, 36%, and 18.6% between weeks 20-24. Adverse effects were reported by 30 (34.9%) and 13 (15.1%) patients between weeks 0-12 and 12-24, leading to discontinuation in 15 (17.4%) patients. Chronic migraine, depression, headache days per month, medication overuse headache, and daily headache at baseline predicted the response between weeks 20-24. CONCLUSION: Candesartan effectiveness and tolerability in migraine prevention was in line with the clinical trials' efficacy.Trial registration: The study protocol is registered in ClinicalTrials.gov (NCT04138316).

Evaluation of the concomitant use of prophylactic treatments in patients with migraine under anti-calcitonin gene-related peptide therapies: The PREVENAC study.

BACKGROUND AND PURPOSE: Anti-calcitonin gene-related peptide (CGRP) therapies are recent preventive therapies approved for both episodic and chronic migraine. One of the measures of effectiveness is the withdrawal of other preventive treatments. The objective of this study is to quantify the impact of anti-CGRP drugs in concomitant preventive treatment in patients with migraine. METHODS: This was an observational, retrospective, multicenter cohort study with patients from nine national headache units. Patients with migraine undergoing treatment for at least 6 months with anti-CGRP antibodies, who were initially associated with some preventive treatment (oral and/or onabotulinumtoxinA) were included. Demographic and clinical variables were collected, as well as variables related to headache. Differences according to withdrawal or nonwithdrawal were evaluated. RESULTS: A total of 408 patients were included, 86.52% women, 48.79 (SD = 1.46) years old. Preventive treatment was withdrawn in 43.87% (179/408), 20.83% partially and 23.04% totally. In 27.45% (112/408), it was maintained exclusively due to comorbidity and in 28.6% (117/408) due to partial efficacy. The most frequent time of withdrawal was between 3 and 5 months after the start of treatment. The baseline characteristics associated with nonwithdrawal were comorbidities: insomnia, hypertension and obesity, chronic migraine, and medication overuse. In the multivariate analysis, the absence of high blood pressure, a greater number of preventive treatments at the start, and a lower number of migraine days/month after anti-CGRP treatment were independently associated with withdrawal of the treatment (p < 0.05). CONCLUSIONS: Anti-CGRP antibodies allow the withdrawal of associated preventive treatment in a significant percentage of patients, which supports its effectiveness in real-life conditions.

Effectiveness, tolerability, and response predictors of preventive anti-CGRP mAbs for migraine in patients over 65 years old: a multicenter real-world case-control study.

OBJECTIVE: To evaluate clinical characteristics, effectiveness, and tolerability of preventive anti- calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) in the elderly. Anti-CGRP mAbs have demonstrated efficacy and safety in patients with migraine although there is limited information regarding the elderly. DESIGN: We performed a multicenter case-control study of cases (patients over 65 years old) and controls (sex-matched patients under 55 years old) with migraine receiving anti-CGRP mAbs. METHODS: We included the demographic characteristics, effectiveness-reduction in the number of monthly headache days (MHD) and monthly migraine days (MMD), 30%, 50%, and 75% responder rates-and treatment emergent adverse events (TEAEs). The primary endpoint was the 50% response rate regarding MHD at weeks 20-24; exploratory 50% response predictors in the elderly were evaluated. RESULTS: In total, 228 patients were included: 114 cases , 114 controls-. Among cases 84.2% (96/114) were women, 79.8% (91/114) CM; mean age of cases 70.1 years old (range: 66-86); mean age of controls was 42.9 years old(range: 38-49). Cases had a higher percentage of vascular risk factors (P < .05),older age of onset (P < .001) and more reported prior preventive treatments (P < .001). Regarding effectiveness in cases, 50% response rate was achieved by 57.5% (42/73) at 20-24 weeks, with lower reduction in the MHD at 8-12 weeks (5 [7.2], 8 [9.1]; P = .001) and a higher reduction in MMD at 20-24 weeks (10.7 [9.1], 9.2 [7.7]; P = .04) compared to the control group. The percentage of TEAEs was similar in the 2 groups. Diagnosis of episodic migraine (EM) (P = .03) and lower number of MHD at baseline (P = .001) were associated with a 50% response in the elderly in univariate analysis. CONCLUSIONS: Our study provides real world evidence of effectiveness and safety of anti-CGRP mAbs for migraine in patients without upper age-limit and possible predictors of anti-CGRP response in the elderly.

Sensitivity of the SNNOOP10 list in the high-risk secondary headache detection.

AIM: To evaluate the diagnostic accuracy of the SNNOOP10 list in the detection of high-risk headaches. METHODS: Patients that visited the Hospital Clínico San Carlos (Madrid) emergency department due to headache that were allocated to a Manchester Triage System level between critical and urgent were prospectively included but retrospectively analysed. A researcher blind to the patients' diagnosis administered a standardised questionnaire and afterwards a neurologist blind to the questionnaire results diagnosed the patient according to the International Classification of Headache Disorders. The primary endpoint was to assess the sensitivity of the SNNOOP10 list in the detection of high-risk headaches. Secondary endpoints included the evaluation of the sensitivity, specificity, positive predictive value, negative predictive value and area under the curve of each SNNOOP10 item. RESULTS: Between April 2015 and October 2021, 100 patients were included. Patients were 44 years old (inter-quartile range: 33.6-64.7) and 57% were female. We identified 37 different diagnoses. Final diagnosis was a primary headache in 33%, secondary headache in 65% and cranial neuralgia in 2%. There were 46 patients that were considered as having high-risk headache. Patients from the primary headache group were younger and more frequently female. Sensitivity of SNNOOP10 list was 100% (95% confidence interval: 90.2%-100%). The items with higher sensitivity were neurologic deficit or disfunction (75.5%), pattern change or recent onset of the headache (64.4%), onset after 50 years (64.4%). The most specific items were posttraumatic onset of headache (94.5%), neoplasm in history (89.1%) and systemic symptoms (89%). The area under the curve of the SNNOOP10 list was 0.66 (95% CI: 0.55-0.76). CONCLUSION: The red flags from the SNNOOP10 list showed a 100% sensitivity in the detection of high-risk headache disorders.

Post-COVID-19 persistent headache: A multicentric 9-months follow-up study of 905 patients.

BACKGROUND: Headache is a frequent symptoms of coronavirus disease 2019 (COVID-19). Its long-term evolution remains unknown. We aim to evaluate the long-term duration of headache in patients that presented headache during the acute phase of COVID-19. METHODS: This is a post-hoc multicenter ambisective study including patients from six different third-level hospitals between 1 March and 27 April 2020. Patients completed 9 months of neurological follow-up. RESULTS: We included 905 patients. Their median age was 51 (IQR 45-65), 66.5% were female, and 52.7% had a prior history of primary headache. The median duration of headache was 14 (6-39) days; however, the headache persisted after 3 months in 19.0% (95% CI: 16.5-21.8%) and after 9 months in 16.0% (95% confidence interval: 13.7-18.7%). Headache intensity during the acute phase was associated with a more prolonged duration of headache (Hazard ratio 0.655; 95% confidence interval: 0.582-0.737). CONCLUSION: The median duration of headache was 2 weeks, but in approximately a fifth of patients it became persistent and followed a chronic daily pattern.

Machine-learning-based approach for predicting response to anti-calcitonin gene-related peptide (CGRP) receptor or ligand antibody treatment in patients with migraine: A multicenter Spanish study.

BACKGROUND AND PURPOSE: Several variables have been reported to be associated with anti-calcitonin gene-related peptide (CGRP) receptor or ligand antibody response, but with differing results. Our objective was to determine whether machine-learning (ML)-based models can predict 6-, 9- and 12-month responses to anti-CGRP receptor or ligand therapies among migraine patients. METHODS: We performed a multicenter analysis of prospectively collected data from patients with migraine receiving anti-CGRP therapies. Demographic and clinical variables were collected. Response rates in the 30% to 50% range, or at least 30%, in the 50% to 75% range, or at least 50%, and response rate of at least 75% regarding the reduction in the number of headache days per month at 6, 9 and 12 months were calculated. A sequential forward feature selector was used for variable selection and ML-based predictive models for the response to anti-CGRP therapies at 6, 9 and 12 months, with model accuracy not less than 70%, were generated. RESULTS: A total of 712 patients were included, 93% were women, and the mean (SD) age was 48 (11.6) years. Eighty-four percent of patients had chronic migraine. ML-based models using headache days/month, migraine days/month and the Headache Impact Test (HIT-6) yielded predictions with an F1 score range of 0.70-0.97 and an area under the receiver-operating curve score range of 0.87-0.98. SHAP (SHapley Additive exPlanations) summary plots and dependence plots were generated to evaluate the relevance of the factors associated with the prediction of the above-mentioned response rates. CONCLUSIONS: Our results show that ML models can predict anti-CGRP response at 6, 9 and 12 months. This study provides a predictive tool that can be used in a real-world setting.

Clinical exacerbation of SARS-CoV2 infection after fingolimod withdrawal.

The role of disease-modifying therapies in patients with autoimmune disorders during severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is controversial. Immunocompromised patients could have a more severe coronavirus disease-2019 (COVID-19) due to the absence of an adequate immune response against the SARS-CoV-2. However, therapies that act on immune response could play a protective role by dampening the cytokine-release syndrome. Fingolimod is a drug used for immune therapy in patients with multiple sclerosis (MS) through the sequestration of activated lymphocytes in the lymph nodes. We report the case of a 57-year-old man with relapsing-remitting MS treated with fingolimod that showed a reactivation of COVID-19 with signs of hyperinflammation syndrome after fingolimod withdrawal. Our case suggests that discontinuation of fingolimod during COVID-19 could imply a worsening of SARS-CoV2 infection.

Management of thunderclap headache in the emergency room: A retrospective cohort study.

INTRODUCTION: The evaluation of red flags is crucial for the accurate the diagnosis of headache disorders, especially for thunderclap headache. We analysed if secondary headache disorders were adequately ruled out in patients that presented to the emergency room with thunderclap headache. METHODS: In this retrospective cohort study, we screened all patients that visited the emergency room for headache, including those that described thunderclap headache. We measured the frequency with which secondary causes were not adequately ruled out. We analysed the order of the exams, the final diagnosis, and the time elapsed between arrival, initial request for imaging, and the completion of the imaging. RESULTS: We screened 2132 patients, and 42 (1.9%) fulfilled eligibility criteria. Mean age was 43.1 ± 17.1 years, and 57% of patients were female. For 22 (52.4%) patients, the work-up was incomplete. Vascular study was missing in 16 (38.1%) patients, cerebrospinal fluid evaluation in nine (21.4%), and magnetic resonance imaging in seven (16.7%), with multiple assessments missing in six (14.3%). There were ten different combinations in which the exams were performed, with the most frequent being the second exam's cerebral spinal fluid evaluation in 18 (52.9%) and the computed tomography angiogram in 10 (29.4%). A secondary cause of thunderclap headache was found in 16 (38.1%) patients, and four (9.5%) had a primary headache diagnosis after an adequate and complete study. CONCLUSIONS: Thunderclap onset was described in one of every 50 patients that visited the emergency room for headache. More than half of these patients were not adequately managed. More than a third of thunderclap headache patients had a secondary cause.

COVID-19 anosmia and gustatory symptoms as a prognosis factor: a subanalysis of the HOPE COVID-19 (Health Outcome Predictive Evaluation for COVID-19) registry.

Olfactory and gustatory dysfunctions (OGD) are a frequent symptom of coronavirus disease 2019 (COVID-19). It has been proposed that the neuroinvasive potential of the novel SARS-CoV-2 could be due to olfactory bulb invasion, conversely studies suggest it could be a good prognostic factor. The aim of the current study was to investigate the prognosis value of OGD in COVID-19. These symptoms were recorded on admission from a cohort study of 5868 patients with confirmed or highly suspected COVID-19 infection included in the multicenter international HOPE Registry (NCT04334291). There was statistical relation in multivariate analysis for OGD in gender, more frequent in female 12.41% vs 8.67% in male, related to age, more frequent under 65 years, presence of hypertension, dyslipidemia, diabetes, smoke, renal insufficiency, lung, heart, cancer and neurological disease. We did not find statistical differences in pregnant (p = 0.505), patient suffering cognitive (p = 0.484), liver (p = 0.1) or immune disease (p = 0.32). There was inverse relation (protective) between OGD and prone positioning (0.005) and death (< 0.0001), but no with ICU (0.165) or mechanical ventilation (0.292). On univariable logistic regression, OGD was found to be inversely related to death in COVID-19 patients. The odds ratio was 0.26 (0.15-0.44) (p < 0.001) and Z was - 5.05. The presence of anosmia is fundamental in the diagnosis of SARS.CoV-2 infection, but also could be important in classifying patients and in therapeutic decisions. Even more knowing that it is an early symptom of the disease. Knowing that other situations as being Afro-American or Latino-American, hypertension, renal insufficiency, or increase of C-reactive protein (CRP) imply a worse prognosis we can make a clinical score to estimate the vital prognosis of the patient. The exact pathogenesis of SARS-CoV-2 that causes olfactory and gustative disorders remains unknown but seems related to the prognosis. This point is fundamental, insomuch as could be a plausible way to find a treatment.

Paroxysmal headache with extracephalic irradiation: Proposal for a new variant of epicrania fugax in a series of five patients.

BACKGROUND: Epicrania fugax consists of brief paroxysms of pain, which radiate in a line or in zigzag trajectory across the surface of the scalp or the face. METHODS: A prospective, descriptive study was performed in five patients presenting with an epicrania fugax-type pain with extracephalic irradiation. RESULTS: All patients were women, and the mean age at onset was 59.8 (standard deviation, 10.9). They had unilateral paroxysms of electrical pain starting at a particular point in the head (parietal, n = 3; vertex, n = 1; frontal, n = 1) and rapidly radiating downwards in a lineal trajectory to reach extracephalic regions (ipsilateral limbs, n = 2; shoulder, n = 2; low neck, n = 1) in 1-3 seconds. Pain intensity was moderate or severe. Three patients had nummular headache at the point where the paroxysms originated. One patient had spontaneous remission, and four patients achieved complete or almost complete response with therapy (onabotulinumtoxinA, n = 2; indomethacin, n = 1; amitriptyline, n = 1; lamotrigine, n = 1). CONCLUSION: The spectrum of epicrania fugax may include paroxysms with extracephalic irradiation. The propagation of pain beyond the head and the face supports the involvement of central mechanisms in the pathophysiology of this entity.

Spectrum of Headaches Associated With SARS-CoV-2 Infection: Study of Healthcare Professionals.

BACKGROUND: Series of patients with SARS-CoV-2 infection report headache in 6%-15% of cases, although some data suggest that the actual frequency is higher, and that headache is not associated with fever. No study published to date has analyzed the characteristics of headache in these patients. OBJECTIVE: To analyze the characteristics of COVID-19 related headaches. METHODS: We conducted a survey of Spaniard healthcare professionals who have been infected by SARS-CoV-2 and presented headache during the course of the disease. The survey addressed respondents' medical history and headache characteristics, and we analyzed the association between both. RESULTS: We analyzed the responses of a sample of 112 healthcare professionals. History of migraine was reported by 20/112 (17.9%) of respondents, history of tension-type headache by 8/112 (7.1%), and history of cluster headache was reported by a single respondent; 82/112(73.2%) of respondents had no history of headache. Headache presented independently of fever, around the third day after symptom onset. The previous history of migraine was associated with a higher frequency of pulsating headache (20% in patients with previous migraine vs 4.3% in those with no history of migraine, P = .013). CONCLUSION: Headache is often holocranial, hemicranial, or occipital, pressing, and worsens with physical activity or head movements. Because the characteristics of the headache and the associated symptoms are heterogeneous in our survey, we suggest that several patterns with specific pathophysiological mechanisms may underlie the headache associated with COVID-19.

Facial epicrania fugax: A prospective series of eight new cases.

Introduction Epicrania fugax (EF) is a primary headache whose main feature is the dynamic character of the pain. EF pain typically moves across different dermatomes in a linear or zigzag trajectory. Recently, a facial variant of EF has been described, with the pain starting in the lower face and radiating upwards. Aim We report eight patients with an EF-type of pain of facial location and either upward or downward radiation. Methods For each patient, we recorded relevant demographic and clinical data. Magnetic resonance imaging (MRI) with fast imaging employing steady state acquisition (FIESTA) was obtained in all cases for the assessment of neurovascular compression of the trigeminal nerve. Results There were seven women and one man, and the mean age was 76.1 years (standard deviation, 11.3). Six patients had a paroxysmal pain starting at the lower face and moving upwards, while two patients had downward radiation. The pain always followed a fixed linear trajectory across different dermatomes. All cases had triggers, and pain intensity was consistently severe. Half of the patients had accompanying autonomic features. Neurovascular compression with imprinting over the trigeminal root on the symptomatic side was identified in three patients. All cases responded to antiepileptic drugs, and three had spontaneous remissions. Conclusions This series reinforces the facial variant of EF and extends the phenotype with cases of downward radiation. It also contributes to enriching the differential diagnosis of facial pain. Neurovascular compression of the trigeminal nerve may be found in some cases, although a possible pathogenic link needs further research.

Thermal Decomposition of NCN: Shock-Tube Study, Quantum Chemical Calculations, and Master-Equation Modeling.

The thermal decomposition of cyanonitrene, NCN, was studied behind reflected shock waves in the temperature range 1790-2960 K at pressures near 1 and 4 bar. Highly diluted mixtures of NCN3 in argon were shock-heated to produce NCN, and concentration-time profiles of C atoms as reaction product were monitored with atomic resonance absorption spectroscopy at 156.1 nm. Calibration was performed with methane pyrolysis experiments. Rate coefficients for the reaction (3)NCN + M → (3)C + N2 + M (R1) were determined from the initial slopes of the C atom concentration-time profiles. Reaction R1 was found to be in the low-pressure regime at the conditions of the experiments. The temperature dependence of the bimolecular rate coefficient can be expressed with the following Arrhenius equation: k1(bim) = (4.2 ± 2.1) × 10(14) exp[-242.3 kJ mol(-1)/(RT)] cm(3) mol(-1) s(-1). The rate coefficients were analyzed by using a master equation with specific rate coefficients from RRKM theory. The necessary molecular data and energies were calculated with quantum chemical methods up to the CCSD(T)/CBS//CCSD/cc-pVTZ level of theory. From the topography of the potential energy surface, it follows that reaction R1 proceeds via isomerization of NCN to CNN and subsequent C-N bond fission along a collinear reaction coordinate without a tight transition state. The calculations reproduce the magnitude and temperature dependence of the rate coefficient and confirm that reaction R1 is in the low-pressure regime under our experimental conditions.

Ultrafast Dynamics of o-Nitrophenol: An Experimental and Theoretical Study.

The photolysis of o-nitrophenol (o-NP), a typical push-pull molecule, is of current interest in atmospheric chemistry as a possible source of nitrous acid (HONO). To characterize the largely unknown photolysis mechanism, the dynamics of the lowest lying excited singlet state (S1) of o-NP was investigated by means of femtosecond transient absorption spectroscopy in solution, time-resolved photoelectron spectroscopy (TRPES) in the gas phase and quantum chemical calculations. Evidence of the unstable aci-nitro isomer is provided both in the liquid and in the gas phase. Our results indicate that the S1 state displays strong charge transfer character, which triggers excited state proton transfer from the OH to the NO2 group as evidenced by a temporal shift of 20 fs of the onset of the photoelectron spectrum. The proton transfer itself is found to be coupled to an out-of-plane rotation of the newly formed HONO group, finally leading to a conical intersection between S1 and the ground state S0. In solution, return to S0 within 0.2-0.3 ps was monitored by stimulated emission. As a competitive relaxation channel, ultrafast intersystem crossing to the upper triplet manifold on a subpicosecond time scale occurs both in solution and in the gas phase. Due to the ultrafast singlet dynamics, we conclude that the much discussed HONO split-off is likely to take place in the triplet manifold.

Experimental and theoretical investigation of the kinetics of the reaction of atomic chlorine with 1,4-dioxane.

The rate coefficients for the reaction of 1,4-dioxane with atomic chlorine were measured from T = 292-360 K using the relative rate method. The reference reactant was isobutane and the experiments were made in argon with atomic chlorine produced by photolysis of small concentrations of Cl2. The rate coefficients were put on an absolute basis by using the published temperature dependence of the absolute rate coefficients for the reference reaction. The rate coefficients for the reaction of Cl with 1,4-dioxane were found to be independent of total pressure from p = 290 to 782 Torr. The experimentally measured rate coefficients showed a weak temperature dependence, given by k(exp)(T) = (8.4(-2.3)(+3.1)) × 10(-10) exp(-(470 ± 110)/(T/K)) cm3 molecule (-1) s(-1). The experimental results are rationalized in terms of statistical rate theory on the basis of molecular data obtained from quantum-chemical calculations. Molecular geometries and frequencies were obtained from MP2/aug-cc-pVDZ calculations, while single-point energies of the stationary points were computed at CCSD(T) level of theory. The calculations indicate that the reaction proceeds by an overall exothermic addition-elimination mechanism via two intermediates, where the rate-determining step is the initial barrier-less association reaction between the chlorine atom and the chair conformer of 1,4-dioxane. This is in contrast to the Br plus 1,4-dioxane reaction studied earlier, where the rate-determining step is a chair-to-boat conformational change of the bromine-dioxane adduct, which is necessary for this reaction to proceed. The remarkable difference in the kinetic behavior of the reactions of 1,4-dioxane with these two halogen atoms can be consistently explained by this change in the reaction mechanism.

Temporal distribution of emergency room visits in patients with migraine and other headaches.

Background: Headache is a leading reason for presentation to the emergency department (ED) with migraine being the most frequently headache. To ensure the adequate staffing of healthcare providers during peak times of headache visits, we analyzed the temporal distribution of emergency department visits in patients presenting with headache and/or migraine.Research design and methods: The authors conducted an ecological study, including all consecutive visits to the ED for headache. Patients were classified according to the IHS Classification. We analyzed circadian, circaseptan and circannual patterns for number of visits, comparing migraine patients with other headache patients.Results: There were 2132 ED visits for headache, including primary headache in 1367 (64.1%) cases; migraine in 963 (45.2%); secondary headache in 404 (18.9%); and unspecified headache in 366 (17.1%). The circadian pattern showed peaks around 11:00-13:00 and 17:00-19:00, with visits during the night shift 45% less frequent (p < 0.001). The circaseptan pattern showed a peak on Monday-Tuesday and a low point on Sunday (p < 0.007). The circannual pattern peaked in March and decreased in June.Conclusions: ED visits for headache showed specific circadian, circaseptan and circannual variations. No differences were found in these patterns when comparing migraine patients to other headache patients.