BackgroundWe demonstrated in the randomised controlled ICON study that 48-week treatment of medically intractable chronic cluster headache (MICCH) with occipital nerve stimulation (ONS) is safe and... Show moreBackgroundWe demonstrated in the randomised controlled ICON study that 48-week treatment of medically intractable chronic cluster headache (MICCH) with occipital nerve stimulation (ONS) is safe and effective. In L-ICON we prospectively evaluate its long-term effectiveness and safety.MethodsICON participants were enrolled in L-ICON immediately after completing ICON. Therefore, earlier ICON participants could be followed longer than later ones. L-ICON inclusion was stopped after the last ICON participant was enrolled in L-ICON and followed for ≥2 years by completing six-monthly questionnaires on attack frequency, side effects, subjective improvement and whether they would recommend ONS to others. Primary outcome was the change in mean weekly attack frequency 2 years after completion of the ICON study compared to baseline. Missing values for log-transformed attack-frequency were imputed for up to 5 years of follow-up. Descriptive analyses are presented as (pooled) geometric or arithmetic means and 95% confidence intervals.FindingsOf 103 eligible participants, 88 (85%) gave informed consent and 73 (83%) were followed for ≥2 year, 61 (69%) ≥ 3 year, 33 (38%) ≥ 5 years and 3 (3%) ≥ 8.5 years. Mean (±SD) follow-up was 4.2 ± 2.2 years for a total of 370 person years (84% of potentially 442 years). The pooled geometric mean (95% CI) weekly attack frequency remained considerably lower after one (4.2; 2.8–6.3), two (5.1; 3.5–7.6) and five years (4.1; 3.0–5.5) compared to baseline (16.2; 14.4–18.3). Of the 49/88 (56%) ICON ≥50% responders, 35/49 (71%) retained this response and 15/39 (38%) ICON non-responders still became a ≥50% responder for at least half the follow-up period. Most participants (69/88; 78% [0.68–0.86]) reported a subjective improvement from baseline at last follow-up and 70/88 (81% [0.70–0.87]) would recommend ONS to others. Hardware-related surgery was required in 44/88 (50%) participants in 112/122 (92%) events (0.35 person-year−1 [0.28–0.41]). We didn't find predictive factors for effectiveness. Show less
Background and ObjectivesFemale-specific factors and psychosocial factors may be important in the prediction of strokebut are not included in prediction models that are currently used. We... Show moreBackground and ObjectivesFemale-specific factors and psychosocial factors may be important in the prediction of strokebut are not included in prediction models that are currently used. We investigated whetheraddition of these factors would improve the performance of prediction models for the risk ofstroke in women younger than 50 years.MethodsWe used data from the Stichting Informatievoorziening voor Zorg en Onderzoek, population-based, primary care database of women aged 20–49 years without a history of cardiovasculardisease. Analyses were stratified by 10-year age intervals at cohort entry. Cox proportionalhazards models to predict stroke risk were developed, including traditional cardiovascularfactors, and compared with models that additionally included female-specific and psychosocialfactors. We compared the risk models using the c-statistic and slope of the calibration curve at afollow-up of 10 years. We developed an age-specific stroke risk prediction tool that may helpcommunicating the risk of stroke in clinical practice.ResultsWe included 409,026 women with a total of 3,990,185 person-years of follow-up. Strokeoccurred in 2,751 women (incidence rate 6.9 [95% CI 6.6–7.2] per 10,000 person-years).Models with only traditional cardiovascular factors performed poorly to moderately in all agegroups: 20–29 years: c-statistic: 0.617 (95% CI 0.592–0.639); 30–39 years: c-statistic: 0.615(95% CI 0.596–0.634); and 40–49 years: c-statistic: 0.585 (95% CI 0.573–0.597). After addingthe female-specific and psychosocial risk factors to the reference models, the model discrimi-nation increased moderately, especially in the age groups 30–39 (Dc-statistic: 0.019) and 40–49years (Dc-statistic: 0.029) compared with the reference models, respectively.DiscussionThe addition of female-specific factors and psychosocial risk factors improves the discrimina-tory performance of prediction models for stroke in women younger than 50 years. Show less
Migraine is associated with altered sensory processing, that may be evident as changes in cortical responsivity due to altered excitability, especially in migraine with aura. Cortical excitability... Show moreMigraine is associated with altered sensory processing, that may be evident as changes in cortical responsivity due to altered excitability, especially in migraine with aura. Cortical excitability can be directly assessed by combining transcranial magnetic stimulation with electroencephalography (TMS-EEG). We measured TMS evoked potential (TEP) amplitude and response consistency as these measures have been linked to cortical excitability but were not yet reported in migraine.We recorded 64-channel EEG during single-pulse TMS on the vertex interictally in 10 people with migraine with aura and 10 healthy controls matched for age, sex and resting motor threshold. On average 160 pulses around resting motor threshold were delivered through a circular coil in clockwise and counterclockwise direction. Trial-averaged TEP responses, frequency spectra and phase clustering (over the entire scalp as well as in frontal, central and occipital midline electrode clusters) were compared between groups, including comparison to sham-stimulation evoked responses.Migraine and control groups had a similar distribution of TEP waveforms over the scalp. In migraine with aura, TEP responses showed reduced amplitude around the frontal and occipital N100 peaks. For the migraine and control groups, responses over the scalp were affected by current direction for the primary motor cortex, somatosensory cortex and sensory association areas, but not for frontal, central or occipital midline clusters.This study provides evidence of altered TEP responses in-between attacks in migraine with aura. Decreased TEP responses around the N100 peak may be indicative of reduced cortical GABA-mediated inhibition and expand observations on enhanced cortical excitability from earlier migraine studies using more indirect measurements. Show less
Objective: Impaired amine metabolism has been associated with the etiology of migraine, that is, why patients continue to get migraine attacks. However, evidence from cerebrospinal fluid (CSF) is... Show moreObjective: Impaired amine metabolism has been associated with the etiology of migraine, that is, why patients continue to get migraine attacks. However, evidence from cerebrospinal fluid (CSF) is lacking. Here, we evaluated individual amine levels, global amine profiles, and amine pathways in CSF and plasma of interictal migraine patients and healthy controls.Methods: CSF and plasma were sampled between 8:30 AM and 1:00 PM, randomly and interchangeably over the time span to avoid any diurnal and seasonal influences, from healthy volunteers and interictal migraine patients, matched for age, sex, and sampling time. The study was approved by the local medical ethics committee. Individual amines (n = 31), global amine profiles, and specific amine pathways were analyzed using a validated ultraperformance liquid chromatography mass spectrometry platform. Results: We analyzed n = 99 participants with migraine with aura, n = 98 with migraine without aura, and n = 96 healthy volunteers. Univariate analysis with Bonferroni correction indicated that CSF L-arginine was reduced in migraine with aura (10.4%, p < 0.001) and without aura (5.0%, p = 0.03). False discovery rate-corrected CSF L-phenylalanine was also lower in migraine with aura (6.9%, p = 0.011) and without aura (8.1%, p = 0.001), p = 0.088 after Bonferroni correction. Multivariate analysis revealed that CSF global amine profiles were similar for both types of migraine (p = 0.64), but distinct from controls (p = 0.009). Global profile analyses were similar in plasma. The strongest associated path-ways with migraine were related to L-arginine metabolism. Interpretation: L-Arginine was decreased in the CSF (but not in plasma) of interictal patients with migraine with or without aura, and associated pathways were altered. This suggests that dysfunction of nitric oxide signaling is involved in susceptibility to getting migraine attacks. Show less
In 1995, a committee of the International Headache Society developed and published the first edition of the Guidelines for Controlled Trials of Drugs in Cluster Headache. These have not been... Show moreIn 1995, a committee of the International Headache Society developed and published the first edition of the Guidelines for Controlled Trials of Drugs in Cluster Headache. These have not been revised. With the emergence of new medications, neuromodulation devices and trial designs, an updated version of the International Headache Society Guidelines for Controlled Clinical Trials in Cluster Headache is warranted. Given the scarcity of evidence-based data for cluster headache therapies, the update is largely consensus-based, but takes into account lessons learned from recent trials and demands by patients. It is intended to apply to both drug and neuromodulation treatments, with specific proposals for the latter when needed. The primary objective is to propose a template for designing high quality, state-of-the-art, controlled clinical trials of acute and preventive treatments in episodic and chronic cluster headache. The recommendations should not be regarded as dogma and alternative solutions to particular methodological problems should be explored in the future and scientifically validated. Show less
Background: The pathophysiology of cluster headache and how cluster episodes are triggered, are still poorly understood. Recurrent inflammation of the trigeminovascular system has been hypothesized... Show moreBackground: The pathophysiology of cluster headache and how cluster episodes are triggered, are still poorly understood. Recurrent inflammation of the trigeminovascular system has been hypothesized. It was noted that some long-term attack-free cluster headache patients suddenly developed a new cluster episode shortly after COVID-19 vaccination. Methods: Cases are described from patients with cluster headache who reported a new cluster episode within days after COVID-19 vaccination. All cases were seen in a tertiary university referral center and a general hospital in the Netherlands between March 2021 and December 2021, when the first COVID-19 vaccinations were carried out in The Netherlands. Clinical characteristics of the previous and new cluster episodes, and time between the onset of a new cluster episode and a previous COVID-19 vaccination were reported. Results: We report seven patients with cluster headache, who had been attack-free for a long time, in whom a new cluster episode occurred within a few days after a COVID-19 vaccination. Interpretation: COVID-19 vaccinations may trigger new cluster episodes in patients with cluster headache, possibly by activating a pro-inflammatory state of the trigeminocervical complex. COVID-19 vaccinations may also exacerbate other neuroinflammatory conditions. Show less
Background and Objectives Increased sensitivity to light and patterns is typically associated with migraine, but has also been anecdotally reported in cluster headache, leading to diagnostic... Show moreBackground and Objectives Increased sensitivity to light and patterns is typically associated with migraine, but has also been anecdotally reported in cluster headache, leading to diagnostic confusion. We wanted to assess whether visual sensitivity is increased ictally and interictally in cluster headache.Methods We used the validated Leiden Visual Sensitivity Scale (L-VISS) questionnaire (range 0-36 points) to measure visual sensitivity in people with episodic or chronic cluster headache: (i) during attacks; (ii) in-between attacks; and in episodic cluster headache (iii) in-between bouts. The L-VISS scores were compared with the L-VISS scores obtained in a previous study in healthy controls and participants with migraine.Results Mean L-VISS scores were higher for: (i) ictal vs interictal cluster headache (episodic cluster headache: 11.9 +/- 8.0 vs. 5.2 +/- 5.5, chronic cluster headache: 13.7 +/- 8.4 vs 5.6 +/- 4.8; p < 0.001); (ii) interictal cluster headache vs controls (5.3 +/- 5.2 vs 3.6 +/- 2.8, p < 0.001); (iii) interictal chronic cluster headache vs interictal ECH in bout (5.9 +/- 0.5 vs 3.8 +/- 0.5, p = 0.009), and (iv) interictal episodic cluster headache in bout vs episodic cluster headache out-of-bout (5.2 +/- 5.5 vs. 3.7 +/- 4.3, p < 0.001). Subjective visual hypersensitivity was reported by 110/121 (91%; 9 missing) participants with cluster headache and was mostly unilateral in 70/110 (64%) and ipsilateral to the ictal pain in 69/70 (99%) participants.Conclusion Cluster headache is associated with increased ictal and interictal visual sensitivity. In contrast to migraine, this is mostly unilateral and ipsilateral on the side of the ictal pain. Show less
Patients suffering from familial hemiplegic migraine type 1 (FHM1) may have a disproportionally severe outcome after head trauma, but the underlying mechanisms are unclear. Hence, we subjected... Show morePatients suffering from familial hemiplegic migraine type 1 (FHM1) may have a disproportionally severe outcome after head trauma, but the underlying mechanisms are unclear. Hence, we subjected knock-in mice carrying the severer S218L or milder R192Q FHM1 gain-of-function missense mutation in the CACNA1A gene that encodes the alpha(1A) subunit of neuronal voltage-gated Ca(V)2.1 (P/Q-type) calcium channels and their wild-type (WT) littermates to experimental traumatic brain injury (TBI) by controlled cortical impact and investigated cortical spreading depolarizations (CSDs), lesion volume, brain edema formation, and functional outcome. After TBI, all mutant mice displayed considerably more CSDs and seizures than WT mice, while S218L mutant mice had a substantially higher mortality. Brain edema formation and the resulting increase in intracranial pressure were more pronounced in mutant mice, while only S218L mutant mice had larger lesion volumes and worse functional outcome. Here, we show that gain of Ca(V)2.1 channel function worsens histopathological and functional outcome after TBI in mice. This phenotype was associated with a higher number of CSDs, increased seizure activity, and more pronounced brain edema formation. Hence, our results suggest increased susceptibility for CSDs and seizures as potential mechanisms for bad outcome after TBI in FHM1 mutation carriers. Show less
Migraine is a common headache disorder. This Primer by Ferrari and colleagues summarizes the epidemiology, pathophysiology, diagnosis and treatment of migraine. Moreover, quality of life issues... Show moreMigraine is a common headache disorder. This Primer by Ferrari and colleagues summarizes the epidemiology, pathophysiology, diagnosis and treatment of migraine. Moreover, quality of life issues faced by patients with migraine and future research avenues are discussed.Migraine is a common, chronic, disorder that is typically characterized by recurrent disabling attacks of headache and accompanying symptoms, including aura. The aetiology is multifactorial with rare monogenic variants. Depression, epilepsy, stroke and myocardial infarction are comorbid diseases. Spreading depolarization probably causes aura and possibly also triggers trigeminal sensory activation, the underlying mechanism for the headache. Despite earlier beliefs, vasodilation is only a secondary phenomenon and vasoconstriction is not essential for antimigraine efficacy. Management includes analgesics or NSAIDs for mild attacks, and, for moderate or severe attacks, triptans or 5HT(1B/1D) receptor agonists. Because of cardiovascular safety concerns, unreliable efficacy and tolerability issues, use of ergots to abort attacks has nearly vanished in most countries. CGRP receptor antagonists (gepants) and lasmiditan, a selective 5HT1(F) receptor agonist, have emerged as effective acute treatments. Intramuscular onabotulinumtoxinA may be helpful in chronic migraine (migraine on >= 15 days per month) and monoclonal antibodies targeting CGRP or its receptor, as well as two gepants, have proven effective and well tolerated for the preventive treatment of migraine. Several neuromodulation modalities have been approved for acute and/or preventive migraine treatment. The emergence of new treatment targets and therapies illustrates the bright future for migraine management. Show less
Organ-on-a-chip (OoC) and microfluidic devices are conventionally produced using microfabrication procedures that require cleanrooms, silicon wafers, and photomasks. The prototyping stage often... Show moreOrgan-on-a-chip (OoC) and microfluidic devices are conventionally produced using microfabrication procedures that require cleanrooms, silicon wafers, and photomasks. The prototyping stage often requires multiple iterations of design steps. A simplified prototyping process could therefore offer major advantages. Here, we describe a rapid and cleanroom-free microfabrication method using maskless photolithography. The approach utilizes a commercial digital micromirror device (DMD)-based setup using 375 nm UV light for backside exposure of an epoxy-based negative photoresist (SU-8) on glass coverslips. We show that microstructures of various geometries and dimensions, microgrooves, and microchannels of different heights can be fabricated. New SU-8 molds and soft lithography-based polydimethylsiloxane (PDMS) chips can thus be produced within hours. We further show that backside UV exposure and grayscale photolithography allow structures of different heights or structures with height gradients to be developed using a single-step fabrication process. Using this approach: (1) digital photomasks can be designed, projected, and quickly adjusted if needed; and (2) SU-8 molds can be fabricated without cleanroom availability, which in turn (3) reduces microfabrication time and costs and (4) expedites prototyping of new OoC devices. Show less
Objective To evaluate individual and group long-term efficacy and safety of erenumab in individuals with episodic migraine (EM) for whom 2-4 prior preventatives had failed.Methods Participants... Show moreObjective To evaluate individual and group long-term efficacy and safety of erenumab in individuals with episodic migraine (EM) for whom 2-4 prior preventatives had failed.Methods Participants completing the 12-week double-blind treatment phase (DBTP) of the LIBERTY study could continue into an open-label extension phase (OLEP) receiving erenumab 140 mg monthly for up to 3 years. Main outcomes assessed at week 112 were: >= 50%, >= 75% and 100% reduction in monthly migraine days (MMD) as group responder rate and individual responder rates, MMD change from baseline, safety and tolerability.Results Overall 240/246 (97.6%) entered the OLEP (118 continuing erenumab, 122 switching from placebo). In total 181/240 (75.4%) reached 112 weeks, 24.6% discontinued, mainly due to lack of efficacy (44.0%), participant decision (37.0%) and adverse events (AEs; 12.0%). The >= 50% responder rate was 57.2% (99/173) at 112 weeks. Of >= 50% responders at the end of the DBTP, 36/52 (69.2%) remained responders at >= 50% and 22/52 (42.3%) at >80% of visits. Of the non-responders at the end of the DBTP, 60/185 (32.4%) converted to a50% responders in at least half the visits and 24/185 (13.0%) converted to >= 50% responders in >80% of visits. Change from baseline at 112 weeks in mean (SD) MMD was -4.2 (5.0) days. Common AEs (>= 10%) were nasopharyngitis, influenza and back pain.Conclusions Efficacy was sustained over 112 weeks in individuals with difficult-to-treat EM for whom 2-4 prior migraine preventives had failed. Erenumab treatment was safe and well tolerated, in-line with previous studies. Show less
Background: An increased risk of stroke in patients with migraine has been primarily found for women. The sex-dependent mechanisms underlying the migraine-stroke association, however, remain... Show moreBackground: An increased risk of stroke in patients with migraine has been primarily found for women. The sex-dependent mechanisms underlying the migraine-stroke association, however, remain unknown. This study aims to explore these sex differences to improve our understanding of pathophysiological mechanisms behind the migraine-stroke association.Methods: We included 2,492 patients with ischemic stroke from the prospective multicenter Dutch Parelsnoer Institute Initiative study, 425 (17%) of whom had a history of migraine. Cardiovascular risk profile, stroke cause (TOAST classification), and outcome [modified Rankin scale (mRS) at 3 months] were compared with both sexes between patients with and without migraine.Results: A history of migraine was not associated with sex differences in the prevalence of conventional cardiovascular risk factors. Women with migraine had an increased risk of stroke at young age (onset < 50 years) compared with women without migraine (RR: 1.7; 95% CI: 1.3-2.3). Men with migraine tended to have more often stroke in the TOAST category other determined etiology (RR: 1.7; 95% CI: 1.0-2.7) in comparison with men without migraine, whereas this increase was not found in women with migraine. Stroke outcome was similar for women with or without migraine (mRS >= 3 RR 1.1; 95% CI 0.7-1.5), whereas men seemed to have a higher risk of poor outcome compared with their counterparts without migraine (mRS >= 3 RR: 1.5; 95% CI: 1.0-2.1).Conclusion: Our results indicate possible sex differences in the pathophysiology underlying the migraine-stroke association, which are unrelated to conventional cardiovascular risk factors. Further research in larger cohorts is needed to validate these findings. Show less
Epidemiological estimates indicate that individuals with epilepsy are more likely to experience headaches, including migraine, than individuals without epilepsy. Headaches can be temporally... Show moreEpidemiological estimates indicate that individuals with epilepsy are more likely to experience headaches, including migraine, than individuals without epilepsy. Headaches can be temporally unrelated to seizures, or can occur before, during or after an episode; seizures and migraine attacks are mostly not temporally linked. The pathophysiological links between headaches (including migraine) and epilepsy are complex and have not yet been fully elucidated. Correct diagnoses and appropriate treatment of headaches in individuals with epilepsy is essential, as headaches can contribute substantially to disease burden. Here, we review the insights that have been made into the associations between headache and epilepsy over the past 5 years, including information on the pathophysiological mechanisms and genetic variants that link the two disorders. We also discuss the current best practice for the management of headaches co-occurring with epilepsy and highlight future challenges for this area of research. Show less
Objective Identifying common genetic variants that confergenetic risk for cluster headache. Methods We conducted a case-control study in the Dutch Leiden University Cluster headache neuro-Analysis... Show moreObjective Identifying common genetic variants that confergenetic risk for cluster headache. Methods We conducted a case-control study in the Dutch Leiden University Cluster headache neuro-Analysis program (LUCA) study population (n = 840) and unselected controls from the Netherlands Epidemiology of Obesity Study (NEO; n = 1,457). Replication was performed in a Norwegian sample of 144 cases from the Trondheim Cluster headache sample and 1,800 controls from the Nord-Trondelag Health Survey (HUNT). Gene set and tissue enrichment analyses, blood cell-derived RNA-sequencing of genes around the risk loci and linkage disequilibrium score regression were part of the downstream analyses. Results An association was found with cluster headache for 4 independent loci (r(2) < 0.1) with genomewide significance (p < 5 x 10(-8)), rs11579212 (odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.33-1.72 near RP11-815 M8.1), rs6541998 (OR = 1.53, 95% CI = 1.37-1.74 near MERTK), rs10184573 (OR = 1.43, 95% CI = 1.26-1.61 near AC093590.1), and rs2499799 (OR = 0.62, 95% CI = 0.54-0.73 near UFL1/FHL5), collectively explaining 7.2% of the variance of cluster headache. SNPs rs11579212, rs10184573, and rs976357, as proxy SNP for rs2499799 (r(2) = 1.0), replicated in the Norwegian sample (p < 0.05). Gene-based mapping yielded ASZ1 as possible fifth locus. RNA-sequencing indicated differential expression of POLR1B and TMEM87B in cluster headache patients. Interpretation This genomewide association study (GWAS) identified and replicated genetic risk loci for cluster headaches with effect sizes larger than those typically seen in complex genetic disorders. ANN NEUROL 2021 Show less
The hypothalamus has been suggested to be important in the initiation cascade of migraine attacks based on clinical and biochemical observations. Previous imaging studies could not disentangle the... Show moreThe hypothalamus has been suggested to be important in the initiation cascade of migraine attacks based on clinical and biochemical observations. Previous imaging studies could not disentangle the changes due to the attack and those due to the trigger compound. With a novel approach, we assessed hypothalamic neuronal activity in early premonitory phases of glyceryl-trinitrate (GTN)-induced and spontaneous migraine attacks. We measured the hypothalamic blood oxygen level-dependent (BOLD) response to oral glucose ingestion with 3T-functional magnetic resonance imaging (MRI) in 27 women, 16 with migraine without aura and 11 controls group matched for age and body mass index (BMI), on 1 day without prior GTN administration and on a second day after GTN administration (to coincide with the premonitory phase of an induced attack). Interestingly, subgroups of patients with and without GTN-triggered attacks could be compared. Additionally, five migraineurs were investigated in a spontaneous premonitory phase. Linear mixed models were used to study between- and within-group effects. Without prior GTN infusion, the BOLD response to glucose was similar in migraine participants and controls (P = .41). After prior GTN infusion, recovery occurred steeper and faster in migraineurs (versus Day 1; P < .0001) and in those who developed an attack versus those who did not (P < .0001). Prior GTN infusion did not alter the glucose-induced response in controls (versus baseline; P = .71). Just before spontaneous attacks, the BOLD-response recovery was also faster (P < .0001). In this study, we found new and direct evidence of altered hypothalamic neuronal function in the immediate preclinical phase of both GTN-provoked and spontaneous migraine attacks. Show less
Background Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish... Show moreBackground Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish whether ONS could serve as an effective treatment for patients with MICCH.Methods The ONS in MICCH (ICON) study is an investigator-initiated, international, multicentre, randomised, double-blind, phase 3, electrical dose-controlled clinical trial. The study took place at four hospitals in the Netherlands, one hospital in Belgium, one in Germany, and one in Hungary. After 12 weeks' baseline observation, patients with MICCH, at least four attacks per week, and history of being non-responsive to at least three standard preventive drugs, were randomly allocated (at a 1:1 ratio using a computer-generated permuted block) to 24 weeks of occipital nerve stimulation at either 100% or 30% of the individually determined range between paraesthesia threshold and neardiscomfort (double-blind study phase). Because ONS causes paraesthesia, preventing masked comparison versus placebo, we compared high-intensity versus low-intensity ONS, which are hypothesised to cause similar paraesthesia, but with different efficacy. In weeks 25-48, participants received individually optimised open-label ONS. The primary outcome was the weekly mean attack frequency in weeks 21-24 compared with baseline across all patients and, if a decrease was shown, to show a group-wise difference. The trial is closed to recruitment (ClinicalTrials.gov NCT01151631).Findings Patients were enrolled between Oct 12, 2010, and Dec 3, 2017. We enrolled 150 patients and randomly assigned 131 (87%) to treatment; 65 (50%) patients to 100% ONS and 66 (50%) to 30% ONS. One of the 66 patients assigned to 30% ONS was not implanted and was therefore excluded from the intention-to-treat analysis. Because the weekly mean attack frequencies at baseline were skewed (median 15.75; IQR 9.44 to 24.75) we used log transformation to analyse the data and medians to present the results. Median weekly mean attack frequencies in the total population decreased from baseline to 7.38 (2.50 to 18.50; p<0.0001) in weeks 21-24, a median change of -5.21 (-11.18 to -0.19; p<0.0001) attacks per week. In the 100% ONS stimulation group, mean attack frequency decreased from 17.58 (9.83 to 29.33) at baseline to 9.50 (3.00 to 21.25) at 21-24 weeks (median change from baseline -4.08, -11.92 to -0.25), and for the 30% ONS stimulation group, mean attack frequency decreased from 15.00 (9.25 to 22.33) to 6.75 (1.50 to 16.50; -6.50, -10.83 to -0.08). The difference in median weekly mean attack frequency between groups at the end of the masked phase in weeks 21-24 was -2.42 (95% CI -5.17 to 3.33). In the masked study phase, 129 adverse events occurred with 100% ONS and 95 occurred with 30% ONS. None of the adverse events was unexpected but 17 with 100% ONS and eight with 30% ONS were labelled as serious, given they required brief hospital admission for minor hardware-related issues. The most common adverse events were local pain, impaired wound healing, neck stiffness, and hardware damage.Interpretation In patients with MICCH, both 100% ONS intensity and 30% ONS intensity substantially reduced attack frequency and were safe and well tolerated. Future research should focus on optimising stimulation protocols and disentangling the underlying mechanism of action. Copyright (C) 2021 Elsevier Ltd. All rights reserved. Show less
Introduction Current prophylactic drugs for cluster headache are associated with limited efficacy, serious side effects and poor tolerability. Greater occipital nerve injection (GON-injection) has... Show moreIntroduction Current prophylactic drugs for cluster headache are associated with limited efficacy, serious side effects and poor tolerability. Greater occipital nerve injection (GON-injection) has been proven effective and safe as a single, one-time injection in episodic (ECH), and to a lesser extent, chronic cluster headache (CCH). We aim to analyse the effectiveness and safety of repeated GON-injections in medically intractable chronic cluster headache (MICCH). Methods Clinical data of all cluster headache patients who had received at least one GON-injection between 2014 and 2018 in our tertiary headache centre were retrieved from patients' medical records. Clinical history was taken as part of routine care shortly before and 6 weeks after GON-injection. Results We identified 47 MICCH patients (79 injections), and compared results with 22 non-MI CCH patients (30 injections) and 50 ECH patients (63 injections). Nineteen MICCH patients received repeated injections (32 in total, range 2-8). Rates of clinical relevant improvement to a first injection were similar in all groups (MICCH: 60%, non-MICCH 73%, ECH 76%; attack freedom: MICCH: 30%, non-MICCH 32%, ECH 43%). Furthermore, no difference in response to the first and second injection was shown between groups (all p > 0.29). Median effect duration in MICCH was 6 weeks (IQR 2.8-12 weeks). Side effects were only mild and local. Conclusion In this retrospective analysis, first and repeated GON-injections were well-tolerated and equally effective in MICCH as in non-MICCH, and ECH. Show less
