Critical reappraisal of intravenous metoclopramide in migraine attack: a systematic review and meta-analysis

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

BACKGROUND

In an effort to improve migraine management around the world, the International Headache Society (IHS) has here developed a list of practical recommendations for the acute pharmacological treatment of migraine. The recommendations are categorized into optimal and essential, in order to provide treatment options for all possible settings, including those with limited access to migraine medications.

METHODS

An IHS steering committee developed a list of clinical questions based on practical issues in the management of migraine. A selected group of international senior and junior headache experts developed the recommendations, following expert consensus and the review of available national and international headache guidelines and guidance documents. Following the initial search, a bibliography of twenty-one national and international guidelines was created and reviewed by the working group.

RESULTS

A total of seventeen questions addressing different aspects of acute migraine treatment have been outlined. For each of them we provide an optimal recommendation, to be used whenever possible, and an essential recommendation to be used when the optimal level cannot be attained.

CONCLUSION

Adoption of these international recommendations will improve the quality of acute migraine treatment around the world, even where pharmacological options remain limited.

The effectiveness of parenteral agents for pain reduction in patients with migraine presenting to emergency settings: A systematic review and network analysis

OBJECTIVES

To assess the comparative effectiveness and safety of parenteral agents for pain reduction in patients with acute migraine.

BACKGROUND

Parenteral agents have been shown to be effective in treating acute migraine pain; however, the comparative effectiveness of different approaches is unclear.

METHODS

Nine electronic databases and gray literature sources were searched to identify randomized clinical trials assessing parenteral agents to treat acute migraine pain in emergency settings. Two independent reviewers completed study screening, data extraction, and Cochrane risk-of-bias assessment, with differences being resolved by adjudication. The protocol of the review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018100096).

RESULTS

A total of 97 unique studies were included, with most studies reporting a high or unclear risk of bias. Monotherapy, as well as combination therapy, successfully reduced pain scores prior to discharge. They also increased the proportion of patients reporting pain relief and being pain free. Across the pain outcomes assessed, combination therapy was one of the higher ranked approaches and provided robust improvements in pain outcomes, including lowering pain scores (mean difference -3.36, 95% confidence interval [CI] -4.64 to -2.08) and increasing the proportion of patients reporting pain relief (risk ratio [RR] 2.83, 95% CI 1.74-4.61). Neuroleptics and metoclopramide also ranked high in terms of the proportion of patients reporting pain relief (neuroleptics RR 2.76, 95% CI 2.12-3.60; metoclopramide RR 2.58, 95% CI 1.90-3.49) and being pain free before emergency department discharge (neuroleptics RR 4.8, 95% CI 3.61-6.49; metoclopramide RR 4.1, 95% CI 3.02-5.44). Most parenteral agents were associated with increased adverse events, particularly combination therapy and neuroleptics.

CONCLUSIONS

Various parenteral agents were found to provide effective pain relief. Considering the consistent improvements across various outcomes, combination therapy, as well as monotherapy of either metoclopramide or neuroleptics are recommended as first-line options for managing acute migraine pain. There are risks of adverse events, especially akathisia, following treatment with these agents. We recommend that a shared decision-making model be considered to effectively identify the best treatment option based on the patient's needs.

Dopaminergic Projections from the Hypothalamic A11 Nucleus to the Spinal Trigeminal Nucleus Are Involved in Bidirectional Migraine Modulation

Clinical imaging studies have revealed that the hypothalamus is activated in migraine patients prior to the onset of and during headache and have also shown that the hypothalamus has increased functional connectivity with the spinal trigeminal nucleus. The dopaminergic system of the hypothalamus plays an important role, and the dopamine-rich A11 nucleus may play an important role in migraine pathogenesis. We used intraperitoneal injections of glyceryl trinitrate to establish a model of acute migraine attack and chronicity in mice, which was verified by photophobia experiments and von Frey experiments. We explored the A11 nucleus and its downstream pathway using immunohistochemical staining and neuronal tracing techniques. During acute migraine attack and chronification, c-fos expression in GABAergic neurons in the A11 nucleus was significantly increased, and inhibition of DA neurons was achieved by binding to GABA A-type receptors on the surface of dopaminergic neurons in the A11 nucleus. However, the expression of tyrosine hydroxylase and glutamic acid decarboxylase proteins in the A11 nucleus of the hypothalamus did not change significantly. Specific destruction of dopaminergic neurons in the A11 nucleus of mice resulted in severe nociceptive sensitization and photophobic behavior. The expression levels of the D1 dopamine receptor and D2 dopamine receptor in the caudal part of the spinal trigeminal nucleus candalis of the chronic migraine model were increased. Skin nociceptive sensitization of mice was slowed by activation of the D2 dopamine receptor in SP5C, and activation of the D1 dopamine receptor reversed this behavioral change. GABAergic neurons in the A11 nucleus were activated and exerted postsynaptic inhibitory effects, which led to a decrease in the amount of DA secreted by the A11 nucleus in the spinal trigeminal nucleus candalis. The reduced DA bound preferentially to the D2 dopamine receptor, thus exerting a defensive effect against headache.

The efficacy and safety of metoclopramide in relieving acute migraine attacks compared with other anti-migraine drugs: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Many drugs are prescribed in relieving acute migraine attacks, we aim to compare metoclopramide with other antimigraine drugs.

METHODS

We searched online databases like PubMed, Cochrane Library, Scopus, and Web of Science till June 2022 for RCTs that compared metoclopramide alone with placebo or active drugs. The main outcomes were the mean change in headache score and complete headache relief. The secondary outcomes were the rescue medications need, side effects, nausea and recurrence rate. We qualitatively reviewed the outcomes. Then, we performed the network meta-analyses (NMAs) when it was possible. which were done by the Frequentist method using the MetaInsight online software.

RESULTS

Sixteen studies were included with a total of 1934 patients: 826 received metoclopramide, 302 received placebo, and 806 received other active drugs. Metoclopramide was effective in reducing headache outcomes even for 24 h. The intravenous route was the most chosen route in the included studies and showed significant positive results regarding headache outcomes; however, the best route whether intramuscular, intravenous, or suppository was not compared in the previous studies. Also, both 10 and 20 mg doses of metoclopramide were effective in improving headache outcomes; however, there was no direct comparison between both doses and the 10 mg dose was the most frequently used dosage. In NMA of headache change after 30 min or 1 h, metoclopramide effect came after granisetron, ketorolac, chlorpromazine, and Dexketoprofen trometamol. Only granisetron's effect was significantly higher than metoclopramide's effect which was only significantly higher than placebo and sumatriptan. In headache-free symptoms, only prochlorperazine was non-significantly higher than metoclopramide which was higher than other medications and showed significantly higher effects only with placebo. In rescue medication, metoclopramide's effect was only non-significantly lower than prochlorperazine and chlorpromazine while its effect was higher than other drugs and showed higher significant effects only than placebo and valproate. In the recurrence rate, studies showed no significant difference between metoclopramide and other drugs. Metoclopramide significantly decreased nausea more than the placebo. Regarding side effects, metoclopramide showed a lower incidence of mild side effects than pethidine and chlorpromazine and showed a higher incidence of mild side effects than placebo, dexamethasone, and ketorolac. The reported extrapyramidal symptoms with metoclopramide were dystonia or akathisia.

CONCLUSION

A dose of 10 mg IV Metoclopramide was effective in relieving migraine attacks with minimal side effects. Compared to other active drugs, it only showed a lower significant effect compared with granisetron regarding headache change while it showed significantly higher effects only with placebo in both rescue medication needs and headache-free symptoms and valproate in only rescue medication need. Also, it significantly decreased headache scores more than placebo and sumatriptan. However, more studies are needed to support our results.

Comparison of efficacy and frequency of akathisia and dystonia between olanzapine, metoclopramide and prochlorperazine in ED headache patients

STUDY OBJECTIVE

To compare the efficacy and frequency of akathisia and dystonia between the dopamine antagonist headache medications olanzapine, metoclopramide and prochlorperazine.

METHODS

This was a retrospective observational cohort study of patients presenting to a large urban level one trauma center between 2010 and 2018. Inclusion criteria was age ≥ 18 who presented to the emergency department with a chief complaint of headache who received either olanzapine, metoclopramide or prochlorperazine. The primary outcome was need for rescue medication. Secondary outcomes were receiving medication for either akathisia or dystonia. Logistic regression was used to identify differences between the three cohorts up to 72 h from initial presentation.

RESULTS

There were 5643 patients who met inclusion criteria. Olanzapine was the most commonly used drug (n = 2994, 53%) followed by prochlorperazine (n = 2100, 37%) and metoclopramide (n = 549, 10%). After adjusting for age and gender, there were no differences in risk for receiving rescue therapy or developing akathisia or dystonia.

CONCLUSION

During initial ED visit and up to 72 h after receiving olanzapine, metoclopramide or prochlorperazine, we found no difference in risk for requiring rescue medication or developing akathisia or dystonia.

The premonitory phase of migraine is due to hypothalamic dysfunction: revisiting the evidence

OBJECTIVE

To critically appraise the evidence for and against premonitory symptoms in migraine being due to hypothalamic dysfunction.

DISCUSSION

Some premonitory symptoms (e.g. fatigue, mood changes, yawning, and food craving) are associated with the physiologic effects of neurotransmitters such as orexins, neuropeptide Y, and dopamine; all of which are expressed in hypothalamic neurons. In rodents, electrophysiologic recordings have shown that these neurotransmitters modulate nociceptive transmission at the level of second-order neurons in the trigeminocervical complex (TCC). Additional insights have been gained from neuroimaging studies that report hypothalamic activation during the premonitory phase of migraine. However, the available evidence is limited by methodologic issues, inconsistent reporting, and a lack of adherence to ICHD definitions of premonitory symptoms (or prodromes) in human experimental studies.

CONCLUSIONS

The current trend to accept that premonitory symptoms are due to hypothalamic dysfunction might be premature. More rigorously designed studies are needed to ascertain whether the neurobiologic basis of premonitory symptoms is due to hypothalamic dysfunction or rather reflects modulatory input to the trigeminovascular system from several cortical and subcortical areas. On a final note, the available epidemiologic data raises questions as to whether the existence of premonitory symptoms and even more so a distinct premonitory phase is a true migraine phenomenon. Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at: https://www.youtube.com/watch?v=d4Y2x0Hr4Q8 .

Pathophysiology and Therapy of Associated Features of Migraine

Migraine is a complex and debilitating disorder that is broadly recognised by its characteristic headache. However, given the wide array of clinical presentations in migraineurs, the headache might not represent the main troublesome symptom and it can even go unnoticed. Understanding migraines exclusively as a pain process is simplistic and certainly hinders management. We describe the mechanisms behind some of the most disabling associated symptoms of migraine, including the relationship between the central and peripheral processes that take part in nausea, osmophobia, phonophobia, vertigo and allodynia. The rationale for the efficacy of the current therapeutic arsenal is also depicted in this article. The associated symptoms to migraine, apart from the painful component, are frequent, under-recognised and can be more deleterious than the headache itself. The clinical anamnesis of a headache patient should enquire about the associated symptoms, and treatment should be considered and individualised. Acknowledging the associated symptoms as a fundamental part of migraine has permitted a deeper and more coherent comprehension of the pathophysiology of migraine.

Pain reduction and adverse effects of intravenous metoclopramide for acute migraine attack: A systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Metoclopramide may be used to treat people suffering from acute migraine. However, no comprehensive investigation on this issue has been recorded. This review will provide more solid evidence for the use of metoclopramide in treating acute migraine.

AIM

To compare the efficacy of intravenous metoclopramide with other therapies in migraine attack treatment in an emergency department (ED).

METHODS

We included randomized controlled trials of participants older than 18 years with acute migraine headaches, which included at least one arm that received intravenous (IV) metoclopramide at the ED. A literature search of PubMed, Web of Science, Cochrane Collaboration, and Reference Citation Analysis on December 31, 2021 retrieved other drugs or placebo-controlled studies without language limitation. The risk of bias was assessed using the Cochrane risk of bias tool. The primary endpoint was pain reduction at 60 min or closest to 1 h after treatment, as measured by the pain scale. Secondary endpoints included adverse effects or reactions resulting from metoclopramide or comparisons.

RESULTS

Fourteen trials with a total of 1661 individuals were eligible for review. The risk of bias ranged from low to intermediate. IV metoclopramide administration was not associated with higher pain reduction at 1 h (Standard mean difference [SMD] = -0.03, 95% confidence interval [CI]: -0.33-0.28, P = 0.87). However, metoclopramide was associated with better pain reduction than placebo (SMD = 1.04, 95%CI: 0.50-1.58, P = 0.0002). In addition, side effects were not significantly different between IV metoclopramide and other drugs or placebo (odds ratio [OR] = 0.76, 95%CI: 0.48-1.19, P = 0.09 and OR = 0.92, 95%CI: 0.31-2.74, P = 0.54, respectively).

CONCLUSION

Metoclopramide is more effective than placebo in treating migraine in the ED. Despite the observed tendency of decreased side effects, its effectiveness compared to other regimens is poorly understood. More research on this area is needed to treat migraine in acute care settings effectively.

Revised guidelines of the French headache society for the diagnosis and management of migraine in adults. Part 2: Pharmacological treatment

The French Headache Society proposes updated French guidelines for the management of migraine. This article presents the second part of the guidelines, which is focused on the pharmacological treatment of migraine, including both the acute treatment of attacks and the prophylaxis of episodic migraine as well as chronic migraine with and without medication overuse. The specific situations that can be encountered in women with migraine are also discussed, including pregnancy, menstrual migraine, contraception and hormonal replacement therapy.

Anti-Inflammatory and Neuromodulatory Effects Induced by Tanacetum parthenium Water Extract: Results from In Silico, In Vitro and Ex Vivo Studies

Tanacetum parthenium (feverfew) has traditionally been employed as a phytotherapeutic remedy in the treatment of migraine. In this study, a commercial T. parthenium water extract was investigated to explore its anti-inflammatory and neuromodulatory effects. Isolated mouse cortexes were exposed to a K⁺ 60 mM Krebs-Ringer buffer and treated with T. parthenium water extract. The prostaglandin E₂ (PGE₂) level, brain-derived neurotrophic factor (BDNF), interleukin-10 (IL-10), and IL-1β gene expression were evaluated in the cortex. The effects on dopamine (DA) release and dopamine transporter (DAT) gene expression were assayed in hypothalamic HypoE22 cells. A bioinformatics analysis was conducted to further investigate the mechanism of action. The extract was effective in reducing cortex PGE₂ release and IL-1β gene expression. In the same experimental system, IL-10 and BDNF gene expressions increased, and in HypoE22 cells, the extract decreased the extracellular dopamine level and increased the DAT gene expression due to the direct interaction of parthenolide with the DAT. Overall, the present findings highlight the efficacy of T. parthenium water extract in controlling the inflammatory pathways that occur during cortical-spreading depression. Additionally, the inhibition of the hypothalamic DA release observed in this study further supports the role of dopaminergic pathways as key targets for novel pharmacological approaches in the management of migraine attacks.

The migraineur’s brain networks: Continuous resting state fMRI over 30 days

Objective

The aim of the current study was to identify typical alterations in resting state connectivity within different stages of the migraine cycle and to thus explore task-free mechanisms of headache attack generation in migraineurs.

Background

Recent evidence in migraine pathophysiology suggests that hours and even days before headache certain changes in brain activity take place, ultimately leading to an attack. Here, we investigate changes before headache onset using resting state functional magnetic resonance imaging (fMRI).

Methods

Nine episodic migraineurs underwent daily resting state functional magnetic resonance imaging for a minimum period of 30 consecutive days, leading to a cumulative number of 282 total days scanned. Thus, data from 15 spontaneous headache attacks were acquired. This allows analysing not only the ictal and the interictal phase of migraine but also the preictal phase. ROI-to-ROI (region of interest) and ROI-to-voxel connectivity was calculated over the migraine cycle.

Results

Within the ROI-to-ROI analysis, the right nucleus accumbens showed enhanced functional connectivity to the left amygdala, hippocampus and gyrus parahippocampalis in the preictal phase compared to the interictal phase. ROI-to-voxel connectivity of the right accumbens with the dorsal rostral pons was enhanced during the preictal phase compared to interictally. Regarding custom defined ROIs, the dorsal pons was ictally functionally more strongly coupled to the hypothalamic area than interictally.

Conclusions

This unique data set suggests that particularly connectivity changes in dopaminergic centres and between the dorsal pons and the hypothalamus are important within migraine attack generation and sustainment.

High-flow oxygen and pro-serotonin agents for non-interventional treatment of post-dural-puncture headache

OBJECTIVE

Post dural puncture headache (PDPH) is a common complication in patients following diagnostic or therapeutic lumbar puncture, procedures requiring epidural access, and spinal surgery. Epidural blood patch (EBP), the gold standard for the treatment of this pathology requires training not provided to emergency physicians. In addition, the presence of concomitant pathology and abnormal laboratory values are contraindications to perform EBP. In presence of these limitations, we sought for a non-interventional management of PDPH utilizing high-flow oxygen and pro-serotonin agents. We reviewed the mechanism of action of this therapy METHODS: To illustrate our proposal, we report a series of twelve consecutive patients with PDPH treated with high-flow oxygen therapy at 12 L/min via a non-rebreathing mask and intravenous metoclopramide.

RESULTS

All patients were treated with this conservative therapy, no adverse reactions were observed. After the intervention, the headache resolved without further indications for PDPH.

CONCLUSION

Our series suggests that combining high-flow oxygen and pro-serotonin agents such metoclopramide in the ED might be a feasible option as effective as the invasive methods used in treating PDPH. This therapy appears to be efficient and to minimize risk, cost and side effects. It presents an easily accessible alternative that should be considered when PDPH is not a viable option.

The Influence of Metoclopramide on Trigeminovascular Nociception: Possible Anti-migraine Mechanism of Action

Metoclopramide is widely used as an abortive migraine therapy due to the advantage of having not only antiemetic, but also analgesic properties. Despite the proven clinical efficacy of metoclopramide in acute migraine, the mechanism of its anti-cephalalgic action has not been entirely elucidated. Taking into account the key role of the trigeminovascular system activation in migraine pathophysiology, we aimed to investigate metoclopramide effects on the excitability of central trigeminovascular neurons and neurogenic dural vasodilation using valid electrophysiological and neurovascular models of trigeminovascular nociception. Extracellular recordings of the activity of second-order dura-sensitive neurons were made in the trigeminocervical complex (TCC) of 16 anaesthetised rats. Cumulative metoclopramide infusion (three steps in 30 min intervals, 5 mg/kg i.v. per step, n = 8) significantly and dose-dependently suppressed both ongoing firing of the TCC neurons and their responses to dural electrical stimulation, maximally to 30%[0-49%] (median[Q1-Q3]) and 4%[0-30%] of the initial level, respectively (both p = 0.001, compared to saline (n = 8)). By contrast, the neurogenic dural vasodilation studied in a separate group of 12 rats was not significantly affected by cumulative infusion of metoclopramide (5 mg/kg i.v. per step, n = 6) compared to both baseline values and the vehicle group (n = 6) (all p > 0.05). These results provide evidence that metoclopramide is unable to affect the peripheral response to trigeminovascular activation, but it does suppress the central response, which is highly predictive of anti-migraine action. Thus, here we show the neurophysiological mechanism underlying the therapeutic efficacy of metoclopramide in migraine.

Hypothalamic regulation of headache and migraine

BACKGROUND

The clinical picture, but also neuroimaging findings, suggested the brainstem and midbrain structures as possible driving or generating structures in migraine.

FINDINGS

This has been intensely discussed in the last decades and the advent of modern imaging studies refined the involvement of rostral parts of the pons in acute migraine attacks, but more importantly suggested a predominant role of the hypothalamus and alterations in hypothalamic functional connectivity shortly before the beginning of migraine headaches. This was shown in the NO-triggered and also in the preictal stage of native human migraine attacks. Another headache type that is clinically even more suggestive of hypothalamic involvement is cluster headache, and indeed a structure in close proximity to the hypothalamus has been identified to play a crucial role in attack generation.

CONCLUSION

It is very likely that spontaneous oscillations of complex networks involving the hypothalamus, brainstem, and dopaminergic networks lead to changes in susceptibility thresholds that ultimately start but also terminate headache attacks. We will review clinical and neuroscience evidence that puts the hypothalamus in the center of scientific attention when attack generation is discussed.

Emerging Novel Pharmacological Non-opioid Therapies in Headache Management: a Comprehensive Review

PURPOSE OF REVIEW

Chronic headache is a significant worldwide problem despite advances in treatment options. Chronic headaches can have significant a detrimental impact on the activities of daily living.

RECENT FINDINGS

Patients who do not obtain relief from chronic head and neck pain from conservative treatments are commonly being managed with interventional treatments. These interventional treatment options include botulinum toxin A, injections, local occipital nerve anesthetic and corticosteroid infiltration, occipital nerve subcutaneous stimulation and occipital nerve pulsed radiofrequency (PRF), sphenopalatine ganglion block, and radiofrequency techniques. Recently, evidence has emerged to support non-opioid-based drug and interventional approaches. Overall, more research is necessary to clarify the safety and efficacy of interventional treatments and to better understand the pathogenesis of chronic headache pain.

Intravenous metoclopramide in the treatment of acute migraines: A randomized, placebo-controlled trial

OBJECTIVES

The present study aimed to evaluate the efficacy and safety of intravenous metoclopramide for acute migraine treatment.

MATERIALS AND METHODS

A double-blind, randomized, parallel-group, placebo-controlled trial was carried out in an academic emergency department. After the patients were assessed for eligibility via the International Headache Society criteria for migraines, they were randomized into 10 mg intravenous metoclopramide and normal saline groups. The headache intensity was evaluated using an 11-point numeric rating scale (NRS) score. The primary outcome measure was determined as the median between-group change in the score at the 30th minute. The secondary outcome measures were rescue medication needs, adverse events, and emergency department (ED) revisits after discharge.

RESULTS

A total of 148 patients were randomized into two equal groups with similar baseline characteristics, including the baseline NRS scores (8 points). The median reduction in the NRS scores at the 30th minute was 4 [interquartile range (IQR): 2-6)] in the metoclopramide group and 3 (IQR: 1-4) in the normal saline group [median difference: -1.0, 95% confidence interval (CI): -2.1 to 0.1]. No serious adverse events were observed, and the rescue medication needs were similar in both groups.

CONCLUSION

No difference was found between intravenous metoclopramide and placebo regarding efficacy and safety in patients with acute migraines.

Treatment of migraine attacks and prevention of migraine: Guidelines by the German Migraine and Headache Society and the German Society of Neurology

In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.

Which is more effective for the treatment of Acute Migraine Attack: Dexketoprofen, Ibuprofen or Metoclopramide?

Objective:

The aim of this study was head-to-head comparison of the efficacy and rate of adverse events of metoclopramide, ibuprofen and dexketoprofen for the acute treatment of migraine attack in the real-life conditions of a busy emergency department (ED).

Methods:

This was a prospective, observational, cross-sectional study. All patients who presented to the ED with a headache fulfilling the inclusion criteria were enrolled. All patients were treated by the attending emergency physicians in their daily routine. If an IV treatment in the ED was found indicated by the EP, they selected one of the options in the written departmental migraine treatment protocol.

Results:

During the study period, 54 patients met the inclusion criteria. The median change in the pain score was significantly different among treatment options (p<0.0001). The median pain score change at the end of the 30 minutes for treatment groups were 7.5 mm (IQR: 7.0-8.0), 5.0 mm (IQR: 4.75-7.0), and 7.0 mm (IQR: 6.0-7.25), respectively (p=0.0002). All three groups were found to be significantly different from each other in the post-hoc analysis.

Conclusion:

All drugs compared in this study are effective in the relief of migraine headache. However, IV dexketoprofen seems to be faster and more effective than metoclopramide and ibuprofen.

Metoclopramide inhibits trigeminovascular activation:evidence for effective acute attack treatment in migraine

BACKGROUND/AIM

Metoclopramide is an effective and commonly used medication in acute migraine treatment but an experimental evidence base is lacking. We aimed to investigate the antimigraine effect of metoclopramide in a migraine model and whether the analgesic effect of metoclopramide was likely to be D₂ receptor-mediated.

MATERIALS AND METHODS

Cortical spreading depression (CSD) was used to model migraine in adult male Wistar rats. Five CSDs were induced by pinprick. Metoclopramide (two different doses), raclopride, or 0.9% saline were administered 30 min before CSD induction. Two hours after the experiments, brain tissues were examined for c-fos activation.

RESULTS

In metoclopramide groups brain stem c-fos expression was significantly lower than in the CSD side of the saline group (P = 0.002). In the raclopride group, ipsilateral brain stem c-fos expression was also lower than in the saline group (P = 0.002). No difference in c-fos expression in the ipsilateral trigeminal nucleus caudalis between the raclopride and metoclopramide groups was observed (P > 0.05).

CONCLUSION

Metoclopramide is shown to suppress trigeminovascular activation for the first time, providing an experimental basis for its role in migraine. The analgesic effect of metoclopramide is likely to be mediated by D₂ receptors since raclopride, a selective D₂ receptor antagonist, suppresses trigeminovascular activation similarly.

Increased risk of Parkinson disease with diabetes mellitus in a population-based study

This nationwide population-based study investigated the risk of Parkinson disease (PD) in relation to diabetes mellitus (DM) through the National Health Insurance Research Database in Taiwan.A retrospective study was conducted, consisting of 36,294 patients who were newly diagnosed with DM between January 1, 2000 and December 31, 2006 and 108,882 individuals without DM as healthy controls from insurance claims data from Taiwan's National Health Research Institutes Dataset. The subjects were followed up until December 31, 2011 or until the first manifestation of PD. The hazard ratio (HR) of DM for PD incidence was estimated by Cox proportional hazard regression model.Compared with the non-DM cohort, the incidence density rate of PD was 1.36-fold higher in the DM cohort (1.53 vs 2.08 per 1000 person-years) with an adjusted HR of 1.19 (95% confidence interval = 1.08-1.32) after adjusting for age, sex, comorbidities, and medication use. The adjusted HR of PD for DM with a larger magnitude was observed in females (1.29, 1.12-1.49); individuals age 65 years and older (1.20, 1.06-1.35); those without schizophrenia (1.20, 1.08-1.33), bipolar disorder (1.20, 1.08-1.33), hypertension (1.18, 1.06-1.32), hyperlipidemia (1.21, 1.09-1.34), chronic obstructive pulmonary disease (1.19, 1.06-1.32), coronary artery disease (1.22, 1.09-1.36), stroke (1.23, 1.10-1.37), asthma (1.20, 1.08-1.34), flunarizine use (1.21, 1.08-1.35), zolpidem use (1.16, 1.04-1.30), Charlson comorbidity index score of 0 (1.23, 1.08-1.40), and those using metoclopramide (1.35, 1.14-1.60) and zolpidem (1.46, 1.12-1.90).DM increased the risk of PD during a mean follow-up of 7.3 years. Further mechanistic research on the effect of DM on PD is needed.

Intranasal Lidocaine in Acute Treatment of Migraine: A Randomized Controlled Trial

STUDY OBJECTIVE

The study aims to evaluate the efficacy and safety of intranasal lidocaine administration for migraine treatment.

METHODS

This single-center, double-blind, randomized, controlled trial was conducted in a tertiary care emergency department. Included patients met the migraine criteria of the International Headache Society. Patients were randomized to intranasal lidocaine or saline solution; all participants received 10 mg of intravenous metoclopramide. Patient pain intensity was assessed with an 11-point numeric rating scale score. The primary outcome measure was the change in pain scores at 15 minutes; secondary outcomes were changes in pain intensity after pain onset and need for rescue medication.

RESULTS

Patients (n=162) were randomized into 2 groups with similar baseline migraine characteristics and numeric rating scale scores. The median reduction in numeric rating scale score at 15 minutes was 3 (interquartile range [IQR] 2 to 5) for the lidocaine group and 2 (IQR 1 to 4) for the saline solution group (median difference=1.0; 95% confidence interval 0.1 to 2.1). The reduction in pain score at 30 minutes was 4 (IQR 3 to 7) for the lidocaine group and 5 (IQR 2 to 7) for the saline solution group (median difference=1.0; 95% confidence interval 0.1 to 2.1). Need for rescue medication did not differ between the groups, and local irritation was the most common adverse event in the lidocaine group.

CONCLUSION

Although intranasal lidocaine was found no more efficacious than normal saline solution in our study, future studies should focus on patients who present earlier after headache onset.

The Development of a Checklist to Enhance Methodological Quality in Intervention Programs

The methodological quality of primary studies is an important issue when performing meta-analyses or systematic reviews. Nevertheless, there are no clear criteria for how methodological quality should be analyzed. Controversies emerge when considering the various theoretical and empirical definitions, especially in relation to three interrelated problems: the lack of representativeness, utility, and feasibility. In this article, we (a) systematize and summarize the available literature about methodological quality in primary studies; (b) propose a specific, parsimonious, 12-items checklist to empirically define the methodological quality of primary studies based on a content validity study; and (c) present an inter-coder reliability study for the resulting 12-items. This paper provides a precise and rigorous description of the development of this checklist, highlighting the clearly specified criteria for the inclusion of items and a substantial inter-coder agreement in the different items. Rather than simply proposing another checklist, however, it then argues that the list constitutes an assessment tool with respect to the representativeness, utility, and feasibility of the most frequent methodological quality items in the literature, one that provides practitioners and researchers with clear criteria for choosing items that may be adequate to their needs. We propose individual methodological features as indicators of quality, arguing that these need to be taken into account when designing, implementing, or evaluating an intervention program. This enhances methodological quality of intervention programs and fosters the cumulative knowledge based on meta-analyses of these interventions. Future development of the checklist is discussed.

Delayed absorption of many (paracetamol, aspirin, other NSAIDs and zolmitriptan) but not all (sumatriptan, rizatriptan) drugs during migraine attacks and most likely normal gastric emptying outside attacks. A review

Background In most pharmacokinetic studies, the oral absorption of drugs is impaired during migraine attacks but exceptions occur. A study on gastric emptying using gastric scintigraphy indicated that gastric stasis also occurs interictally in migraine. These studies were reviewed critically. Results In seven studies, mainly investigating NSAIDs and analgesics, the early absorption of the drugs during 112 migraine attacks was delayed. The absorption of sumatriptan is usual in therapeutic doses, and rizatriptan was normal during 131 migraine attacks. The interictal gastric stasis observed using gastric emptying scintigraphy (GES) with solids ( n = 13) could not be confirmed in a larger study ( n = 27) using the same method. Also gastric emptying measured with GES with liquids ( n = 7) and epigastric impedance ( n = 64) was normal outside migraine attacks. Conclusions and possible clinical implications Drug absorption is not generally impaired during migraine attacks. Gastric emptying is most likely normal in the majority of migraine patients outside attacks. Prokinetic and antiemetic drugs such as metoclopramide and domperidone should not be routinely combined with oral analgesics or oral triptans. If, however, nausea is severe or vomiting occurs, treatment with an antiemetic with proven efficacy on the nausea of migraine can be indicated.