No wearing-off effect of erenumab or fremanezumab for chronic migraine prevention: a single-center, real-world, observational study

BACKGROUND

The present study investigates the wearing-off effect in adults with chronic migraine treated with erenumab or fremanezumab.

METHODS

This real-world observational study was based on pre-collected headache diaries from chronic migraine patients in treatment with either monthly injections of 140 mg of erenumab or 225 mg of fremanezumab. Consistent wearing-off was defined as an increase of ≥2 weekly migraine days in the last week compared to the second week over two consecutive 4-week treatment periods. The primary endpoint was wearing-off in the total population. The secondary endpoints were difference in wearing-off in (i) a subgroup of patients treated with erenumab and fremanezumab and (ii) consistent wearing-off in patients with a ≥30% reduction in monthly migraine days, compared to baseline, in the two consecutive treatment months.

RESULTS

In total, 100 patients (erenumab: n = 60, fremanezumab: n = 40) were included. Sixty-two out of 100 (62%) patients had consistent ≥30% treatment response on antibody therapy in both months (erenumab: n = 36, fremanezumab: n = 26). There was no consistent wearing-off over the two consecutive months from week 2 to week 4 (3.04%, p = 0.558). There was no wearing-off within the erenumab (p = 0.194) or the fremanezumab (p = 0.581) groups. Among the ≥30% treatment responders, there was no consistent wearing-off over the two consecutive months (2.6%, p = 0.573).

CONCLUSIONS

There was no wearing-off in treatment responders, which is in alignment with premarketing data from placebo-controlled phase III studies. These data suggest that patients should be informed upfront that no wearing-off effect is expected because anxiety for attacks at the end of the month per se may generate migraine attacks.

CGRP receptor antagonists (gepants)

Small molecule calcitonin gene-related peptide (CGRP) receptor antagonists are commonly referred to as gepants. The first generation of gepants provided the first line of evidence of CGRP-mediated antimigraine medication in 2004-2011. However, further development was halted due to either lack of oral availability or concerns of hepatotoxicity. More than 15 years later, the first second generation of gepants, ubrogepant and rimegepant, are now approved for the acute treatment of migraine with or without aura. Furthermore, a novel and promising third-generation gepant, zavegepant, has recently been approved as well. In this chapter, we review the evidence supporting the effectiveness, safety, and tolerability of gepants for the acute treatment of migraine. Furthermore, we discuss the potential limitations and future directions of this class of migraine-specific medication.

Debate: differences and similarities between tension-type headache and migraine

Tension-type headache (TTH) and migraine are two common primary headaches distinguished by clinical characteristics according to the 3^rd edition of the International Classification of Headache Disorders. Migraine is identified by specific features such as being more prevalent in females, being aggravated by physical activity, certain genetic factors, having photophobia, phonophobia, nausea, vomiting, or aura, and responding to specific drugs. Nonetheless, TTH and migraine share some common characteristics, such as onset occurring in the 20 s, and being triggered by psychological factors like stress, moderate pain severity, and mild nausea in chronic TTH. Both conditions involve the trigeminovascular system in their pathophysiology. However, distinguishing between TTH and migraine in clinical practice, research, and epidemiological studies can be challenging, as there is a lack of specific diagnostic tests and biomarkers. Moreover, both conditions may coexist, further complicating the diagnostic process. This review aims to explore the similarities and differences in the pathophysiology, epidemiology, burden and disability, comorbidities, and responses to pharmacological and non-pharmacological treatments of TTH and migraine. The review also discusses future research directions to address the diagnostic challenges and improve the understanding and management of these conditions.

Efficacy, safety and indirect comparisons of lasmiditan, rimegepant, and ubrogepant for the acute treatment of migraine: A systematic review and network meta-analysis of the literature

BACKGROUND

We performed a random-effects network meta-analysis to study the efficacy and safety of newly developed drugs for the acute treatment of migraine attacks.

METHODS

MEDLINE via PubMed, Embase and The Cochrane Register of Controlled Trials were searched from inception to 11 February 2022. Phase 3 randomized controlled trials examining all formulations of lasmiditan, rimegepant and ubrogepant for the acute treatment of adults with migraine, were included. Data were extracted following the PRISMA guidelines.

RESULTS

Seven studies (SAMURAI, SPARTAN, CENTURION, Study 302, Study 303, ACHIEVE I and II) involving n = 12,859 patients were included. All treatments were superior in efficacy to placebo. Lasmiditan 200 mg showed the highest two-hour pain freedom, while two-hour freedom from most bothersome symptom was equally achieved by the higher doses of lasmiditan (100 and 200 mg), rimegepant and the higher doses of ubrogepant (50 and 100 mg). The odds of treatment-emergent adverse events were greatest with all doses of lasmiditan.

CONCLUSION

Lasmiditan 200 mg was the most effective intervention in the treatment of migraine attacks, although it was associated with high degrees of dizziness, nausea and somnolence. Rimegepant showed slightly lower, but similar efficacy rates to lasmiditan. Ubrogepant had overall the best tolerability profile. These conclusions are limited by the absence of head-to-head comparisons, limitations of individual trials and of the meta-analysis methodology itself.PROSPERO trial registration: CRD42022308224.

The role of cytokines in migraine: A systematic review

BACKGROUND

Cytokines are important endogenous substances that are involved in immune and inflammatory responses. Neurogenic inflammation has been proposed to play a role in migraine involving altered cytokine levels. Therefore, we aimed to provide a systematic review on the current knowledge on cytokine levels in migraine patients during and outside attacks.

METHODS

Databases of PubMed and Embase were systematically searched for studies investigating cytokine levels in migraine patients during and outside attacks.

RESULTS

Screening yielded identification of 45 articles investigating 18 cytokines in total. We found that the interictal level of the anti-inflammatory cytokine, interleukin 10, was decreased, while the level of transforming growth factor beta 1 was increased in migraine patients compared to controls. Levels of pro-inflammatory cytokines, tumor necrosis factor α and interleukin 6, were increased outside attacks compared to controls. Ictal levels of cytokines were unchanged or varying compared to the interictal state in migraine patients. Three studies reported dynamic cytokines levels during the course of an attack.

CONCLUSION

The findings of the current review underline a possible involvement of cytokines in the proposed inflammatory mechanisms of migraine. However, future studies are needed to expand our knowledge of the exact role of cytokines in the migraine pathophysiology with focus on cytokines TNF-α, IL-1ß, IL-6 and IL-10 while applying refined methodology.

Prevalence of neck pain in migraine: A systematic review and meta-analysis

BACKGROUND

Neck pain is a frequent complaint among patients with migraine and seems to be correlated with the headache frequency. Neck pain is more common in patients with chronic migraine compared to episodic migraine. However, prevalence of neck pain in patients with migraine varies among studies.

OBJECTIVE

To estimate the prevalence of neck pain in patients with migraine and non-headache controls in observational studies.

METHODS

A systematic literature search on PubMed and Embase was conducted to identify studies reporting prevalence of neck pain in migraine patients. This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data was extracted by two independent investigators and results were pooled using random-effects meta-analysis. The protocol was registered with PROSPERO (CRD42021264898).

RESULTS

The search identified 2490 citations of which 30 contained relevant original population based and clinic-based data. Among these, 24 studies provided data eligible for the analysis. The meta-analysis for clinic-based studies demonstrated that the pooled relative frequency of neck pain was 77.0% (95% CI: 69.0-86.4) in the migraine group and 23.2% (95% CI:18.6-28.5) in the non-headache control group. Neck pain was more frequent in patients with chronic migraine (87.0%, 95% CI: 77.0-93.0) compared to episodic migraine (77.0%, 95% CI: 69.0-84.0). Neck pain was 12 times more prevalent in migraine patients compared to non-headache controls and two times more prevalent in patients with chronic migraine compared to episodic migraine. The calculated heterogeneity (I² values) ranged from 61.3% to 72.0%.

CONCLUSION

Neck pain is a frequent complaint among patients with migraine. The heterogeneity among the studies emphasize important aspects to consider in future research of neck pain in migraine to improve our understanding of the driving mechanisms of neck pain in a major group of migraine patients.

Interictal pontine metabolism in migraine without aura patients: A 3 Tesla proton magnetic resonance spectroscopy study

In the pons, glutamatergic mechanisms are involved in regulating inhibitory descending pain modulation, serotoninergic neurotransmission as well as modulating the sensory transmission of the trigeminovascular system. Migraine involves altered pontine activation and structural changes, while biochemical, genetic and clinical evidence suggests that altered interictal pontine glutamate levels may be an important pathophysiological feature of migraine abetting to attack initiation. Migraine without aura patients were scanned outside attacks using a proton magnetic resonance spectroscopy protocol optimized for the pons at 3 Tesla. The measurements were performed on two separate days to increase accuracy and compared to similar repeated measurements in healthy controls. We found that interictal glutamate (i.e. Glx) levels in the pons of migraine patients (n = 33) were not different from healthy controls (n = 16) (p = 0.098), while total creatine levels were markedly increased in patients (9%, p = 0.009). There was no correlation of glutamate or total creatine levels to migraine frequency, days since the last attack, usual pain intensity of attacks or disease duration. In conclusion, migraine is not associated with altered interictal pontine glutamate levels. However, the novel finding of increased total creatine levels suggests that disequilibrium in the pontine energy metabolism could be an important feature of migraine pathophysiology.

The chronobiology of migraine: a systematic review

Background

The paroxysmal nature of migraine is a hallmark of the disease. Some patients report increased attack frequency at certain seasons or towards the end of the week, while others experience diurnal variations of migraine attack onset. This systematic review investigates the chronobiology of migraine and its relation to the periodicity of attacks in existing literature to further understand the oscillating nature of migraine.

Main body

PubMed and Embase were systematically searched and screened for eligible articles with outcome measures relating to a circadian, weekly or seasonal distribution of migraine attacks. We found that the majority of studies reported morning hours (6 am–12 pm) as the peak time of onset for migraine attacks. More studies reported Saturday as weekly peak day of attack. There was no clear seasonal variation of migraine due to methodological differences (primarily related to location), however four out of five studies conducted in Norway reported the same yearly peak time indicating a possible seasonal periodicity phenomenon of migraine.

Conclusions

The findings of the current review suggest a possible role of chronobiologic rhythms to the periodicity of migraine attacks. Future studies are, however, still needed to provide more knowledge of the oscillating nature of migraine.

Migraine: epidemiology and systems of care

Migraine is a neurovascular disorder that affects over 1 billion people worldwide. Its widespread prevalence, and associated disability, have a range of negative and substantial effects not only on those immediately affected but also on their families, colleagues, employers, and society. To reduce this global burden, concerted efforts are needed to implement and improve migraine care that is supported by informed health-care policies. In this Series paper, we summarise the data on migraine epidemiology, including estimates of its very considerable burden on the global economy. First, we present the challenges that continue to obstruct provision of adequate care worldwide. Second, we outline the advantages of integrated and coordinated systems of care, in which primary and specialist care complement and support each other; the use of comprehensive referral and linkage protocols should enable continuity of care between these systems levels. Finally, we describe challenges in low and middle-income countries, including countries with poor public health education, inadequate access to medication, and insufficient formal education and training of health-care professionals resulting in misdiagnosis, mismanagement, and wastage of resources.

Glutamate levels and perfusion in pons during migraine attacks: A 3T MRI study using proton spectroscopy and arterial spin labeling

Migraine is a complex disorder, involving peripheral and central brain structures, where mechanisms and site of attack initiation are an unresolved puzzle. While abnormal pontine neuronal activation during migraine attacks has been reported, exact implication of this finding is unknown. Evidence suggests an important role of glutamate in migraine, implying a possible association of pontine hyperactivity to increased glutamate levels. Migraine without aura patients were scanned during attacks after calcitonin gene-related peptide and sildenafil in a double-blind, randomized, double-dummy, cross-over design, on two separate study days, by proton magnetic resonance spectroscopy and pseudo-continuous arterial spin labeling at 3T. Headache characteristics were recorded until 24 h after drug administrations. Twenty-six patients were scanned during migraine, yielding a total of 41 attacks. Cerebral blood flow increased in dorsolateral pons, ipsilateral to pain side during attacks, compared to outside attacks (13.6%, p = 0.009). Glutamate levels in the same area remained unchanged during attacks (p = 0.873), while total creatine levels increased (3.5%, p = 0.041). In conclusion, dorsolateral pontine activation during migraine was not associated with higher glutamate levels. However, the concurrently increased total creatine levels may suggest an altered energy metabolism, which should be investigated in future studies to elucidate the role of pons in acute migraine.

Feasibility of Glutamate and GABA Detection in Pons and Thalamus at 3T and 7T by Proton Magnetic Resonance Spectroscopy

Glutamate detection in pons and thalamus using proton magnetic resonance spectroscopy (¹H-MRS) after an intervention is of interest for studying various brain disorders. However, ¹H-MRS in these brain regions is challenging and time-consuming, especially in longitudinal study designs. ¹H-MRS of more cortical structures at the ultrahigh magnetic field strength of 7T yields an improved spectral output, including separation of the glutamate signal from the glutamine signal, in a shorter and more feasible scan time, as compared to conventional clinical field strengths. For this purpose, we compared the feasibility of ¹H-MRS at 3T and 7T in pons and thalamus by applying a longitudinal study design of repeated measures on same day and three separate days at both field strength in five healthy participants. Total ¹H-MRS acquisition time was reduced by a factor 3.75 for pons and by a factor 3 for thalamus at 7T as compared to 3T. We found higher spectral signal-to-noise ratio (SNR) (p < 0.001), lower linewidth (p = 0.001) and lower Cramér–Rao lower bounds (CRLB) (p < 0.001) for the combined glutamate and glutamine signal (Glx) in thalamus at 7T as compared to 3T. In pons, CRLB of Glx and SNR were lower at 7T (p = 0.002 and p = 0.006), with no differences in linewidth compared to 3T. Mean within-subject variability of Glx concentration estimates was lower at 7T compared to 3T for both pons and thalamus. At 7T, it was possible to assess glutamate and γ-aminobutyric acid (GABA) simultaneously in pons and thalamus. In conclusion, ¹H-MRS at 7T resulted in improved spectral quality while allowing shorter scan times than at 3T as well as estimation of the pure glutamate signal in pons and thalamus. This opens up the opportunity for multimodal study designs and multiregional subcortical ¹H-MRS research. Glutamate and GABA measurement at 7T in pons and thalamus is advantageous for future investigations of excitatory–inhibitory mechanisms in brain disorders.

Cerebrovascular effects of endothelin-1 investigated using high-resolution magnetic resonance imaging in healthy volunteers

Endothelin-1 (ET-1) is a highly potent vasoconstrictor peptide released from vascular endothelium. ET-1 plays a major role in cerebrovascular disorders and likely worsens the outcome of acute ischaemic stroke and aneurismal subarachnoid haemorrhage through vasoconstriction and cerebral blood flow (CBF) reduction. Disorders that increase the risk of stroke, including hypertension, diabetes mellitus, and acute myocardial infarction, are associated with increased plasma levels of ET-1. The in vivo human cerebrovascular effects of systemic ET-1 infusion have not previously been investigated. In a two-way crossover, randomized, double-blind design, we used advanced 3 tesla MRI methods to investigate the effects of high-dose intravenous ET-1 on intra- and extracranial artery circumferences, global and regional CBF, and cerebral metabolic rate of oxygen (CMRO₂) in 14 healthy volunteers. Following ET-1 infusion, we observed a 14% increase of mean arterial blood pressure, a 5% decrease of middle cerebral artery (MCA) circumference, but no effects on extracerebral arteries and no effects on CBF or CMRO₂. Collectively, the findings indicate MCA constriction secondarily to blood pressure increase and not due to a direct vasoconstrictor effect of ET-1. We suggest that, as opposed to ET-1 in the subarachnoid space, intravascular ET-1 does not exert direct cerebrovascular effects in humans.

Intravenous Endothelin-1 Infusion Does Not Induce Aura or Headache in Migraine Patients With Aura

OBJECTIVE

To investigate whether intravenously infused provokes migraine aura and migraine headache in migraine patients with aura.

BACKGROUND

Migraine with aura has been associated with endothelial dysfunction and increased stroke risk. The initiating mechanism of migraine aura symptoms is not known. Experimental provocation of migraine headache using vasoactive peptides has provided tremendous advances in the understanding of migraine pathophysiology but substances that can induce migraine aura have not been identified. Endothelin-1 (ET-1), an endogenous, potent vasoconstrictor peptide released from the vascular endothelium, has been proposed to trigger migraine aura. This hypothesis is based on reports of increased plasma ET-1 levels early during the migraine attacks and the observation that ET-1 applied to the cortical surface potently induces the cortical spreading depolarization, the underlying electrophysiological phenomenon of migraine aura, in animals. Further, endothelial damage due to, for example, carotid puncture and vascular pathology is known to trigger aura episodes.

METHODS

We investigated whether intravascular ET-1 would provoke migraine aura in patients. Using a two-way crossover, randomized, placebo-controlled, double-blind design, we infused high-dose (8 ng/kg/minutes for 20 minutes) intravenous ET-1 in patients with migraine with typical aura. The primary end-point was the difference in incidence of migraine aura between ET-1 and placebo. Experiments were carried out at a public tertiary headache center (Danish Headache Center, Rigshospitalet Glostrup, Denmark).

RESULTS

Fourteen patients received intravenous ET-1. No patients reported migraine aura symptoms or migraine headache during or up to 24 hours following the ET-1 infusion. Four patients reported mild to moderate headache only on the ET-1 day, 3 patients reported moderate headache on the placebo day, and 1 patient reported mild headache on both days. No serious adverse events occurred during or after infusion.

CONCLUSIONS

Provocation of migraine aura by procedures or conditions involving vascular irritation is unlikely to be mediated by ET-1.

Ictal neck pain investigated in the interictal state – a search for the origin of pain

Background

Neck pain is reported in more than 50% of migraine patients during migraine attacks and may be an important source to migraine pain.

Objectives

To investigate phenotypical differences between migraine patients with and without ictal neck pain in the interictal phase. Additionally, to prospectively examine the association between pericranial muscle tenderness and the impending migraine attack.

Methods

Migraine patients (n = 100) and controls (n = 46) underwent a semi-structured interview and sensory testing interictally. Pericranial muscle tenderness was determined using total tenderness score and local tenderness score. The occurrence of migraine attacks was then prospectively recorded for the following seven days.

Results

Patients with ictal neck pain had increased tenderness of pericranial neck muscles compared to migraine patients without ( p = 0.023). Ictal neck pain was not associated with migraine localization, tension-type headache, or markers of central sensitization. Prospective data of 84 patients showed that tenderness of trigeminal sensory innervated muscles increased the migraine attack rate ( p = 0.035).

Conclusion

The distinction of migraine patients based on the occurrence of ictal neck pain could indicate migraine subtypes and possible involvement of peripheral tissue in the pathophysiology. Whether treatment responses differ among these groups would be fascinating. Additionally, we found that cephalic muscle tenderness is a risk factor for an impending migraine attack.

Investigation of distinct molecular pathways in migraine induction using calcitonin gene-related peptide and sildenafil

Objective

Migraine displays clinical heterogeneity of attack features and attack triggers. The question is whether this heterogeneity is explained by distinct intracellular signaling pathways leading to attacks with distinct clinical features. One well-known migraine-inducing pathway is mediated by cyclic adenosine monophosphate and another by cyclic guanosine monophosphate. Calcitonin gene-related peptide triggers migraine via the cyclic adenosine monophosphate pathway and sildenafil via the cyclic guanosine monophosphate pathway. To date, no studies have examined whether migraine induction mediated via the cyclic adenosine monophosphate and cyclic guanosine monophosphate pathways yields similar attacks within the same patients.

Methods

Patients were subjected to migraine induction on two separate days using calcitonin gene-related peptide (1.5 µg/min for 20 minutes) and sildenafil (100 mg) in a double-blind, randomized, double-dummy, cross-over design. Data on headache intensity, characteristics and accompanying symptoms were collected until 24 hours after drug administration.

Results

Thirty-four patients were enrolled and 27 completed both study days. Seventeen patients developed migraine after both study drugs (63%; 95% CI: 42–81). Eight patients developed migraine on one day only (seven after sildenafil and one after calcitonin gene-related peptide). Two patients did not develop migraine on either day. Headache laterality, nausea, photophobia and phonophobia were similar between drugs in 77%, 65%, 100%, and 94%, respectively, of the 17 patients who developed attacks on both days.

Conclusion

A majority of patients developed migraine after both calcitonin gene-related peptide and sildenafil. This supports the hypothesis that the cyclic adenosine monophosphate and cyclic guanosine monophosphate intracellular signaling pathways in migraine induction converge in a common cellular determinator, which ultimately triggers the same attacks. Trial registration: ClinicalTrials.gov Identifier: NCT03143465.

Correction to: Ultra-high field MR angiography in human migraine models: a 3.0 T/7.0 T comparison study

After publication of the original article [1], the authors have notified us that an updated version of Figures 1, 2 and 3 should have been published. The incorrect and revised figures can be found below.

Investigating macrophage-mediated inflammation in migraine using ultrasmall superparamagnetic iron oxide-enhanced 3T magnetic resonance imaging

Background

Initiating mechanisms of migraine headache remain poorly understood and a biomarker of migraine does not exist. Inflammation pertaining to the wall of cerebral arteries and brain parenchyma has been suggested to play a role in migraine pathophysiology.

Objective

We conducted the first experimental human study to investigate macrophage-mediated inflammation as a possible biomarker of migraine.

Methods

Using ultrasmall superparamagnetic iron oxide (USPIO)-enhanced 3T magnetic resonance imaging (MRI), we investigated the presence of macrophages in cerebral artery walls and in brain parenchyma of patients with migraine without aura. We used the phosphodiesterase-3-inhibitor cilostazol as an experimental migraine trigger, and investigated both patients who received sumatriptan treatment, and patients who did not. To validate our use of USPIO-enhanced MRI, we included a preclinical mouse model with subcutaneous capsaicin injection in the trigeminal V1 area. The study is registered at ClinicalTrials.gov with the identifier NCT02549898.

Results

A total of 28 female patients with migraine without aura underwent a baseline MRI scan, ingested cilostazol, developed a migraine-like attack, and underwent an USPIO-enhanced MRI scan > 24 hours after intravenous administration of USPIO. Twelve patients treated their attack with 6 mg s.c. sumatriptan, while the remaining 16 patients received no migraine-specific rescue medication. The preclinical model confirmed that USPIO-enhanced MRI detects macrophage-mediated inflammation. In patients, however, migraine attacks were not associated with increased USPIO signal on the pain side of the head compared to the non-pain side.

Conclusion

Our findings suggest that migraine without aura is not associated with macrophage-mediated inflammation specific to the head pain side.

Ultra-high field MR angiography in human migraine models: a 3.0 T/7.0 T comparison study

BACKGROUND

Sildenafil and calcitonin gene-related peptide both dilate the intradural segments of the middle meningeal artery measured with 3.0 tesla (T) MR angiography. Here we hypothesized that an increase in field strength to 7.0 T and concomitant enhanced voxel resolution would lower variance in measurements of dilation in the intradural middle meningeal artery.

METHODS

Five subjects completed two sessions at respectively 3.0 T and 7.0 T. Each session comprised MR angiography scans once before and twice after administration of sildenafil, calcitonin gene-related peptide or placebo in a three-way, crossover, double-blind, placebo-controlled design.

RESULTS

Standard deviations of arterial circumference revealed no difference between 3.0 T and 7.0 T measurements (p = 0.379). We found a decrease in standard deviation from our original angiography analysis software (QMra) to a newer (LAVA) software package (p < 0.001). Furthermore, we found that the dilation after sildenafil and calcitonin gene-related peptide were comparable between 3.0 T and 7.0 T.

CONCLUSIONS

Our findings suggest no gain from the increase in voxel resolution but cemented dilatory findings from earlier. The implemented software update improved variance in circumference measurements in the intradural middle meningeal artery, which should be exploited in future studies.

TRIAL REGISTRATION

The study is part of a parent study, which is registered at ClinicalTrials.gov ( NCT03143465 ).

Meningeal contribution to migraine pain: a magnetic resonance angiography study

The origin of migraine pain is unknown but possibly implicates the dura mater, which is pain sensitive in proximity to the meningeal arteries. Therefore, subtle changes in vessel calibre on the head pain side could reflect activation of dural perivascular nociceptors that leads to migraine headache. To test this hypothesis, we measured circumference changes of cranial arteries in patients with cilostazol-induced unilateral migraine without aura using 3 T high resolution magnetic resonance angiography. The middle meningeal artery was of key interest, as it is the main supply of the dura mater. We also measured the superficial temporal and external carotid arteries as additional extracranial segments, and the middle cerebral, the cerebral and cavernous parts of the internal carotid (ICAcerebral and ICAcavernous), and the basilar arteries as intracranial arterial segments. Magnetic resonance angiography scans were performed at baseline, migraine onset, after sumatriptan, and ≥27 h after migraine onset. Thirty patients underwent magnetic resonance angiography scans, of which 26 patients developed unilateral attacks of migraine without aura and were included in the final analysis. Eleven patients treated their migraine with sumatriptan while the remaining 15 patients did not treat their attacks with analgesics or triptans. At migraine onset, only the middle meningeal artery exhibited greater circumference increase on the pain side (0.24 ± 0.37 mm) compared to the non-pain side (0.06 ± 0.38 mm) (P = 0.002). None of the remaining arteries revealed any pain-side specific changes in circumference (P > 0.05), but exhibited bilateral dilation. Sumatriptan constricted all extracerebral arteries (P < 0.05). In the late phase of migraine, we found sustained bilateral dilation of the middle meningeal artery. In conclusion, onset of migraine is associated with increase in middle meningeal artery circumference specific to the head pain side. Our findings suggest that vasodilation of the middle meningeal artery may be a surrogate marker for activation of dural perivascular nociceptors, indicating a meningeal site of migraine headache.10.1093/brain/awy300_video1awy300media15983750185001.

Efficacy of direct-acting anti-viral therapy on chronic, naïve hepatitis C virus patients of Punjab, Pakistan: a cross-sectional study

The success of interferon-free regimens using new direct-acting antiviral (DAA) is a revolution and major breakthrough in the development of new therapeutic options against hepatitis C virus (HCV). Accumulating evidence suggest sustained virological response (SVR) with DAA in 95% of patients. To date, however, there are very few data related to efficacy of DAA in the Pakistani population. We aimed to investigate the efficacy of sofosbuvir-based regimen among Pakistani population. A total of 1,913 patients who attained SVR24 after being treated with sofosbuvir and ribavirin from August 2015 to March 2017 were enrolled in this study. We analyzed the demographic, clinical and virological data and screened all patients for HCV in March 2017 to evaluate the response rate. We found an overall response rate of 92.8%. In addition, we also observed lower response rates among older patients. It can be inferred that a large proportion of patients achieved SVR after treatment with sofosbuvir-based regimen.

Migraine induction with calcitonin gene-related peptide in patients from erenumab trials

BACKGROUND

Migraine prevention with erenumab and migraine induction by calcitonin gene-related peptide (CGRP) both carry notable individual variance. We wanted to explore a possible association between individual efficacy of anti-CGRP treatment and susceptibility to migraine induction by CGRP.

METHODS

Thirteen migraine patients, previously enrolled in erenumab anti-CGRP receptor monoclonal antibody trials, received CGRP in a double-blind, placebo-controlled, randomized cross-over design to investigate their susceptibility to migraine induction. A standardized questionnaire was used to assess the efficacy of previous antibody treatment. The patients were stratified into groups of high responders and poor responders. Primary outcomes were incidence of migraine-like attacks and area under the curve of headache intensity after infusion of CGRP and placebo. All interviews and experiments were performed in laboratories at the Danish Headache Center, Copenhagen, Denmark.

RESULTS

Ten high responders and three poor responders were included. CGRP induced migraine-like attacks in ten (77%) patients, whereof two were poor responders, compared to none after placebo (p = 0.002). The area under the curve for headache intensity was greater after CGRP, compared to placebo, at 0-90 min (p = 0.009), and 2-12 h (p = 0.014). The median peak headache intensity score was 5 (5-9) after CGRP, compared to 2 (0-4) after placebo (p = 0.004).

CONCLUSIONS

Patients with an excellent effect of erenumab are highly susceptible to CGRP provocation. If an association is evident, CGRP provocation could prove a biomarker for predicting antibody treatment efficacy.

TRIAL REGISTRATION

Retrospectively registered at clinicaltrials.gov with identifier: NCT03481400 .

Current understanding of thalamic structure and function in migraine

OBJECTIVE

To review and discuss the literature on the role of thalamic structure and function in migraine.

DISCUSSION

The thalamus holds an important position in our understanding of allodynia, central sensitization and photophobia in migraine. Structural and functional findings suggest abnormal functional connectivity between the thalamus and various cortical regions pointing towards an altered pain processing in migraine. Pharmacological nociceptive modulation suggests that the thalamus is a potential drug target.

CONCLUSION

A critical role for the thalamus in migraine-related allodynia and photophobia is well established. Additionally, the thalamus is most likely involved in the dysfunctional pain modulation and processing in migraine, but further research is needed to clarify the exact clinical implications of these findings.

Sildenafil and calcitonin gene-related peptide dilate intradural arteries: A 3T MR angiography study in healthy volunteers

Background

Sildenafil and calcitonin gene-related peptide are vasoactive substances that induce migraine attacks in patients. The intradural arteries are thought to be involved, but these have never been examined in vivo. Sildenafil is the only migraine-inducing compound for which cephalic, extracranial artery dilation is not reported. Here, we investigate the effects of sildenafil and calcitonin gene-related peptide on the extracranial and intradural parts of the middle meningeal artery.

Methods

In a double-blind, randomized, three-way crossover, placebo-controlled head-to-head comparison study, MR-angiography was recorded in healthy volunteers at baseline and twice after study drug (sildenafil/ calcitonin gene-related peptide/saline) administration. Circumferences of extracranial and intradural middle meningeal artery segments were measured using semi-automated analysis software. The area under the curve for circumference change was compared using paired t-tests between study days.

Results

Twelve healthy volunteers completed the study. The area under the curveBaseline-120min was significantly larger on both the sildenafil and the calcitonin gene-related peptide day in the intradural middle meningeal artery (calcitonin gene-related peptide, p = 0.013; sildenafil, p = 0.027) and the extracranial middle meningeal artery (calcitonin gene-related peptide, p = 0.0003; sildenafil, p = 0.021), compared to placebo. Peak intradural middle meningeal artery dilation was 9.9% (95% CI [2.9–16.9]) after sildenafil (T30min) and 12.5% (95% CI [8.1–16.8]) after calcitonin gene-related peptide (T30min). Peak dilation of the extracranial middle meningeal artery after calcitonin gene-related peptide (T30min) was 15.7% (95% CI [11.2–20.1]) and 18.9% (95% CI [12.8–24.9]) after sildenafil (T120min).

Conclusion

An important novel finding is that both sildenafil and calcitonin gene-related peptide dilate intradural arteries, supporting the notion that all known pharmacological migraine triggers dilate cephalic vessels. We suggest that intradural artery dilation is associated with headache induced by calcitonin gene-related peptide and sildenafil.

Effects of sildenafil and calcitonin gene-related peptide on brainstem glutamate levels: a pharmacological proton magnetic resonance spectroscopy study at 3.0 T

BACKGROUND

Studies involving human pharmacological migraine models have predominantly focused on the vasoactive effects of headache-inducing drugs, including sildenafil and calcitonin gene-related peptide (CGRP). However, the role of possible glutamate level changes in the brainstem and thalamus is of emerging interest in the field of migraine research bringing forth the need for a novel, validated method to study the biochemical effects in these areas.

METHODS

We applied an optimized in vivo human pharmacological proton (¹H) magnetic resonance spectroscopy (MRS) protocol (PRESS, repetition time 3000 ms, echo time 37.6-38.3 ms) at 3.0 T in combination with sildenafil and CGRP in a double-blind, placebo-controlled, randomized, double-dummy, three-way cross-over design. Seventeen healthy participants were scanned with the ¹H-MRS protocol at baseline and twice (at 40 min and 140 min) after drug administration to investigate the sildenafil- and CGRP-induced glutamate changes in both brainstem and thalamus.

RESULTS

The glutamate levels increased transiently in the brainstem at 40-70 min after sildenafil administration compared to placebo (5.6%, P = 0.039). We found no sildenafil-induced glutamate changes in the thalamus, and no CGRP-induced glutamate changes in the brainstem or thalamus compared to placebo. Both sildenafil and CGRP induced headache in 53%-62% of participants. We found no interaction in the glutamate levels in the brainstem or thalamus between participants who developed sildenafil and/or CGRP-induced headache as compared to participants who did not.

CONCLUSIONS

The transient sildenafil-induced glutamate change in the brainstem possibly reflects increased excitability of the brainstem neurons. CGRP did not induce brainstem or thalamic glutamate changes, suggesting that it rather exerts its headache-inducing effects on the peripheral trigeminal pain pathways.

Increased brainstem perfusion, but no blood-brain barrier disruption, during attacks of migraine with aura

See Moskowitz (doi:10.1093/brain/awx099) for a scientific commentary on this article.The migraine aura is characterized by transient focal cortical disturbances causing dramatic neurological symptoms that are usually followed by migraine headache. It is currently not understood how the aura symptoms are related to the headache phase of migraine. Animal studies suggest that cortical spreading depression, the likely mechanism of migraine aura, causes disruption of the blood-brain barrier and noxious stimulation of trigeminal afferents leading to activation of brainstem nuclei and triggering of migraine headache. We used the sensitive and validated technique of dynamic contrast-enhanced high-field magnetic resonance imaging to simultaneously investigate blood-brain barrier permeability and tissue perfusion in the brainstem (at the level of the lower pons), visual cortex, and brain areas of the anterior, middle and posterior circulation during spontaneous attacks of migraine with aura. Patients reported to our institution to undergo magnetic resonance imaging during the headache phase after presenting with typical visual aura. Nineteen patients were scanned during attacks and on an attack-free day. The mean time from attack onset to scanning was 7.6 h. We found increased brainstem perfusion bilaterally during migraine with aura attacks. Perfusion also increased in the visual cortex and posterior white matter following migraine aura. We found no increase in blood-brain barrier permeability in any of the investigated regions. There was no correlation between blood-brain barrier permeability, brain perfusion, and time from symptom onset to examination or pain intensity. Our findings demonstrate hyperperfusion in brainstem during the headache phase of migraine with aura, while the blood-brain barrier remains intact during attacks of migraine with aura. These data thus contradict the preclinical hypothesis of cortical spreading depression-induced blood-brain barrier disruption as a possible mechanism linking aura and headache.awx089media15422686892001.

Association between tumour necrosis-α gene polymorphisms and acne vulgaris in a Pakistani population

BACKGROUND

The cytokine tumour necrosis factor (TNF)-α is a well-studied potent candidate mediator that is systemically involved in a variety of inflammatory diseases. Several single nucleotide polymorphisms (SNPs) of the TNF-α gene have been studied with regard the pathogenesis of acne vulgaris, but the results have been inconclusive.

AIM

This case-control study investigated the association of the TNF -308 G>A and -238 G>A SNPs with acne vulgaris in a high-risk Pakistani population.

METHODS

In total, 160 healthy controls and 140 patients with acne were enrolled in this study. Polymorphisms were determined by PCR and restriction fragment length polymorphism analysis.

RESULTS

Our data showed that the TNF -308 G>A and TNF -238 G>A SNPs were present at a significantly higher rate in cases than in controls (P < 0.01 and P < 0.02; respectively). There was a significant difference between the G and A alleles from patients with acne and controls for -308 G>A (OR = 1.5, 95% CI = 1.07-2.19, P < 0.02) and -238 G>A (OR=1.6, 95% CI = 1.06-2.44, P = 0.02) genotype. Moreover, the severity of acne was significantly associated with TNF genotype (TNF -308 G>A: χ² = 34.6, P < 0.001; TNF -238 G>AL χ² = 12.9, P < 0.01).

CONCLUSION

Our data suggest that the TNF -308 G>A and TNF -238 G>A SNPs may contribute to the pathogenesis of acne in the study population. Furthermore, patients with severe acne showed an increased frequency of mutant TNF genotypes at -308 and -238 compared with patients with less severe acne.

The interleukin-6 and interleukin-1A gene promoter polymorphism is associated with the pathogenesis of acne vulgaris

Acne vulgaris is a skin disorder with a complex pathogenesis. Better treatment strategies require comprehensive knowledge of molecular factors contributing to the acne pathophysiology. Recent studies are focused on investigating the influence of inflammatory cytokines on the disease. This case-control study investigated the association of IL-6-572 G/C and IL-1A-889 C/T gene polymorphisms with acne in a Pakistani population. Pakistani subjects (380 healthy controls and 430 acne patients) were enrolled in this study. Polymorphism in the promoter region of IL-6-572 and IL-1A-889 was determined by polymerase chain reaction and restriction fragment length polymorphism. The IL-6-572 and IL-1A-889 variant genotypes were significantly associated with the acne pathogenesis. The IL-6-572C and the IL-1A-889T alleles were significantly high in the patient vs. control group (p < 0.0001 for both loci). The IL-6-572 G/C and IL-1A-889 C/T variant allele haplotypes showed significantly high prevalence in patients with acne; G-T (P = 0.0014), C-C (P < 0.0001), and C-T (P < 0.0001). This is the first report on the association between the IL-6-572 G/C polymorphism and acne among any population. The IL-1A-889 C/T polymorphism is also significantly linked with acne in the study population; the -889 C/T association with acne has been reported in one ethnic group previously. Our findings suggest that the IL-6-572C and IL-1A-889T alleles may contribute to the pathogenesis of acne in a Pakistani population. Further studies are required to verify these findings in other populations.

Inhibition of Cxcr 1 and 2 Delays Preterm Delivery and Reduces Neonatal Mortality in a Mouse Model of Chorioamnionitis

Intrauterine infection is one of the main etiologies associated with preterm delivery. Cytokines involved in chorioamnionitis, including IL-1, TNF-α, IL-6, IL-8, and MCP1, activate different pathways that lead to preterm delivery. Antileukinate (AL) is a potent selective IL-8 inhibitor that binds to CXC receptors 1&2 on neutrophils, thereby inhibiting IL-8-induced neutrophil chemotaxis and degranulation. Since CXC receptors 1&2 are critically involved in the pathology of chorioamnionitis, their inhibition with AL may have therapeutic potential. Four timed-pregnant C57BL6 mice groups were studied. LPS group received LPS intraperitoneally on gestational day (GD) 15. The AL group received LPS on GD15 followed immediately by intraperitoneal AL injection and repeated on GD16, and 17. Control groups received either saline, or no injections. In the LPS group, 90% delivered within 24 hours after LPS administration compared to 20% in the AL group. The LPS group had 85% stillborn compared to 15% in the AL group. Uterine histopathology AL group showed evidence of less inflammatory reaction compared to the LPS group. Uterine tissue and serum from the AL group had a significant reduction of inflammatory cytokines compared with the LPS group. Cytokine levels in brain and lung tissues from surviving pups were not significantly different between the AL and control groups. Our data show that antileukinate significantly delays preterm delivery in a mouse model of chorioamnionitis, and reduces neonatal mortality and morbidity.

Primary cytomegalovirus infection in pregnant Egyptian women confirmed by cytomegalovirus IgG avidity testing

OBJECTIVE

To determine the frequency of primary cytomegalovirus (CMV) infection in pregnant Egyptian women using CMV IgG avidity testing.

SUBJECTS AND METHODS

A cross-sectional study was conducted at Suez Canal University Hospital, Ismailia, Egypt. A total of 546 pregnant women, presenting for routine antenatal screening, were tested for CMV IgG and IgM using a commercially available enzyme-linked immunosorbent assay (ELISA). Sera from CMV IgM-positive women were tested by CMV IgG avidity assay.

RESULTS

All the 546 pregnant women were seropositive for anti-CMV IgG. Of the 546 women, 40 (7.3%) were positive or equivocal for IgM antibodies. All sera from the 40 women (IgG+/IgM+) showed a high or intermediate CMV IgG avidity index. Of the 40 women, 23 (57.5%) were in the second or third trimesters of pregnancy and had their first-trimester blood retrieved, and the tested CMV IgG avidity assay showed a high avidity index.

CONCLUSION

Women who were IgM positive had no primary CMV infection in the index pregnancy as evidenced by the high CMV IgG avidity testing.

Efficacy of parvaquone in the treatment of naturally occurring theileriosis in cattle in Iraq

Parvaquone was tested in cattle infected with Theileria annulata when they were presented at clinics in the vicinity of Baghdad. Out of over 200 cases presented with suspected theileriosis between July 1984 and July 1985, the drug was used in 45 cases where theileriosis was confirmed by microscopic examination of blood and lymph node biopsy smears. Twenty seven of the cases were considered mild and 18 cases severe. Weights of the cattle were estimated and parvaquone was administered by intramuscular injection at a nominal dose of 20 mg/kg. A single treatment with parvaquone was used in 25 cases and 20 cases were treated twice but there was no correlation between severity of disease and the number of treatments given. Twelve cases (27%) also received antibacterial therapy. All cases were in exotic cattle or cattle born from exotic (imported) cattle and 64% of the cases were in cattle under six months of age. Temperatures dropped immediately after treatment and the majority were normal (below 39.5 degrees C) by two to three days after the first treatment. Of the 45 cases treated 43 recovered. This compares very favourably with a previously reported mortality of 66% in untreated imported cattle in Iraq.