Calcitonin gene-related peptide: a possible biomarker in migraine patients with patent foramen ovale

BACKGROUND

Serum CGRP has been found to increase during migraine attack. However, whether CGRP can identify MA with PFO subtypes in MA remains unknown. This study aimed to investigate the differential expression of calcitonin gene-related peptide (CGRP) between migraine (MA) patients with and without patent foramen ovale (PFO), and to evaluate the predictive value of CGRP for MA with PFO.

METHODS

A total of 153 patients with MA, 51 patients with PFO and 102 patients without. Venous blood was drawn and HIT-6 score was calculated during the onset of MA, and blood routine, inflammatory indexes and serum CGRP were detected. The differences in serum markers and HIT-6 scores were compared between the two groups, and the risk factors of MA with PFO were determined by univariate and multivariate logistics regression. Furthermore, the correlation between CGRP level with right-to-left shunt (RLS) grades and headache impact test-6 (HIT-6) score in MA patients with PFO were assessed. Independent risk factors were screened out by multivariate Logistic regression analysis. We used the receiver operating characteristic (ROC) curve to analyze the diagnostic value of these risk factors in MA complicated with PFO.

RESULTS

The serum CGRP level and HIT-6 scores in the MA with PFO group were significantly higher than those in the MA group (P < 0.001). Multivariate regression analysis showed that CGRP was an independent risk factor for MA with PFO (OR = 1.698, 95% CI = 1.325-2.179, P < 0.001). CGRP values ​​increased with the increase of RLS grade(Spearmen rho = 0.703, P < 0.001). Furthermore, a positive correlation between CGRP and HIT-6 scores was found (Spearmen rho = 0.227; P = 0.016). ROC curve showed that the optimal cut-off value for diagnosing MA with PFO was 79 pg/mL, the area under the curve (AUC) for predicting MA with PFO was 0.845, with 72.55% sensitivity and 78.43% specificity.

CONCLUSIONS

MA patients with PFO have higher serum CGRP level. elevated CGRP concentration was associated with higher RLS grade and increased HIT-6 score. Higher serum CGRP level has certain clinical value in predicting PFO in MA patients.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Zhuhai Hospital of Integrated Traditional Chinese and Western Medicine (Ethics batch number: 20,201,215,005).

Are anti-calcitonin gene-related peptide monoclonal antibodies effective in treating migraine aura? A pilot prospective observational cohort study

BACKGROUND

About 15% to one third of migraineurs experience aura symptoms. Aura is a reversible focal neurological phenomenon involving visual, sensory, speech, and motor symptoms that usually precede migraine pain. Monoclonal antibodies against calcitonin-related peptide (anti- CGRP mAbs) are effective in preventing chronic and episodic migraine, but little is known about their effectiveness on specifically preventing migraine with aura.

METHODS

This is a pilot prospective observational cohort study, aiming at evaluating the effectiveness and safety of Erenumab, Fremanezumab or Galcanezumab for the treatment of migraine aura. We enrolled 14 patients at the Headache Centre of University Federico II of Naples. Duration of follow-up was 12 months. We assessed mean monthly days with aura symptoms, with or without subsequent headache, as well as mean monthly days with headache and mean monthly MIDAS score, by reviewing standardized paper patient headache diaries every three months.

RESULTS

A significant decrease in mean monthly aura days was observed throughout the observation period (median baseline: 13, interquartile range: 4-16; after 12 months: 1, interquartile range: 0-3, p < 0.001). We observed a statistically significant decrease in mean monthly headache days as well (median baseline 21, interquartile range: 16-30; after 12 months: 5, interquartile range: 4-7, p < 0.001). During the 12-month treatment period, none of the 14 patients reported mild or serious adverse events.

CONCLUSION

Our findings suggest that anti-CGRP mAbs are highly effective in migraine with aura, both in reducing mean monthly aura days and mean monthly days with headache.

The right amygdala and migraine: Analyzing volume reduction and its relationship with symptom severity

This study aimed to explore the relationship between gray matter volume changes and various clinical parameters in patients with migraine, focusing on symptom severity, quality of life, and states of depression and anxiety. Using a case-control design, we examined 33 patients with migraine, with or without aura, and 27 age-matched healthy subjects. We used magnetic resonance imaging to assess the volumes of 140 bilateral brain regions. Clinical evaluations included the Migraine Disability Assessment, the Migraine Specific Quality of Life Questionnaire, the Center for Epidemiologic Studies Depression scale, Spielberger's State and Trait Anxiety scales, and the Japanese version of the Montreal Cognitive Assessment. We compared the scores of these measures between migraine patients and healthy controls to examine the interplay between brain structure and clinical symptoms. Significant volumetric differences were observed in the pallidum and amygdala between migraine patients and healthy individuals. The reduction in the right amygdala volume correlated significantly with migraine severity as measured by the Migraine Disability Assessment. Path analysis revealed a model where Migraine Disability Assessment scores were influenced by Migraine Specific Quality of Life Questionnaire outcomes, which were further affected by depression, anxiety, and a low right pallidum volume. Our findings suggest that the chronicity and severity of migraine headaches specifically affect the right amygdala. Our path model suggests a complex relationship whereby migraine disability is strongly influenced by quality of life, which is, in turn, affected by psychological states, such as anxiety and depression.

Novel compound heterozygous ATP1A2 variants in a patient with fetal akinesia/hypokinesia sequence

ATP1A2 encodes a subunit of sodium/potassium-transporting adenosine triphosphatase (Na+ /K+ -ATPase). Heterozygous pathogenic variants of ATP1A2 cause familial hemiplegic migraine, alternating hemiplegia of childhood, and developmental and epileptic encephalopathy. Biallelic loss-of-function variants in ATP1A2 lead to fetal akinesia, respiratory insufficiency, microcephaly, polymicrogyria, and dysmorphic facies, resulting in fetal death. Here, we describe a patient with compound heterozygous ATP1A2 variants consisting of missense and nonsense variants. He survived after birth with brain malformations and the fetal akinesia/hypokinesia sequence. We report a novel type of compound heterozygous variant that might extend the disease spectrum of ATP1A2.

Investigations of the migraine-provoking effect of levcromakalim in patients with migraine with aura

BACKGROUND/HYPOTHESIS

Experimental provocation studies have yielded important insights in migraine pathophysiology. Levcromakalim has been previously shown to induce migraine-like attacks with and without aura. In this study, we aim to further explore the migraine aura-inducing potential of levcromakalim.

METHODS

In a double-blind, randomized, placebo-controlled cross-over study, 27 adult participants with migraine with aura received intravenous infusions of levcromakalim and saline. Headache, aura and associated symptoms were evaluated for 24 hours following administration of the study drug. The primary endpoint was occurrence of migraine-like attacks with or without aura in the 24-hour observation period.

RESULTS

Thirteen participants developed migraine-like attacks on the active day only (P = 0.0098), and four participants developed aura on the active day only (P = 0.68). The median time to onset of migraine-like headache was three hours, and the median time to onset of aura was 27.5 minutes.

CONCLUSION/INTERPRETATION

Our findings affirm the potent migraine-inducing effect of levcromakalim. We observed a lower induction-rate of migraine aura than previously reported. Further studies are warranted to identify predictors of migraine aura following levcromakalim.

CLINICALTRIALS.GOV IDENTIFIER

NCT04905654.

Causal association between systemic lupus erythematosus and the risk of migraine: A Mendelian randomization study

BACKGROUND

Numerous studies have found that patients with systemic lupus erythematosus (SLE) often have comorbid headache, especially migraine. However, the causal relationship between genetically determined SLE and migraine risk remains unclear. Therefore, we conducted a Mendelian randomization (MR) study to explore this causal association.

METHODS

Genome-wide association studies (GWAS) provided the instrumental variables. We selected summary data from GWAS of SLE as exposure (5201 SLE patients and 9066 controls). Both outcome GWAS data were from the Finnish Gene GWAS, including migraine with aura, migraine with aura and triptan purchases, and migraine without aura. The main MR approach was inverse-variance weighted. Pleiotropy and heterogeneity were detected using the MR pleiotropy residual sum and outlier, MR-Egger intercept test, leave-one-out analysis, and Cochran's Q test.

RESULTS

There was a significant association between genetically predicted SLE susceptibility and increased risk of migraine with aura [odds ratio (OR) = 1.05, 95% confidence interval (CI) = 1.02-1.08, p = .001]. The result was consistent when the outcome was migraine with aura and triptan purchases [OR = 1.05, 95% CI = 1.02-1.08, p = .001]. However, we found no association between SLE and migraine without aura. Our MR study showed no pleiotropy or heterogeneity.

CONCLUSIONS

Our study indicates that genetic susceptibility to SLE increases the incidence of migraine with aura but not migraine without aura. It is necessary for the routine evaluation and early recognition of migraine in patients with SLE in clinical settings.

Reduction in retinal microvascular perfusion during migraine attacks

OBJECTIVE

To determine if there are changes in structure and function of the retinal vasculature during and between migraine attacks using optical coherence tomography angiography (OCTA).

BACKGROUND

Migraine attacks commonly include visual symptoms, but the potential role of the retina in these symptoms is not well understood. OCTA is a rapid, non-invasive imaging technique that is used to visualize the retinal microvasculature with high spatial resolution in a clinical setting. In this study we used OCTA to quantify different features of the retinal vasculature in patients with migraine during and between attacks, as well as in healthy controls (HCs).

METHODS

We performed a prospective cohort study of 37 patients with migraine with aura (MA) (median [interquartile range, IQR] age of 37 [14] years, 86% female) and 30 with migraine without aura (MO) (median [IQR] age of 37 [17] years, 77% female) and 20 HCs (median [IQR] age of 35 [7] years, 50% female). Macular OCTA scans were obtained for all participants for the interictal analysis. In 12 MA and eight MO, scans were captured both during and outside of migraine attacks and five HCs had initial and repeat scans. In addition to analyzing the morphology of the foveal avascular zone, we calculated the vessel flux index (VFI), which is an indicator of retinal perfusion and conventional metrics (such as vessel area density) in the foveal and parafoveal regions.

RESULTS

There was a significant difference in the parafoveal VFI in the ictal state between the groups (p = 0.009). During migraine attacks there was a significant reduction in the parafoveal region VFI in MA (-7%, 95% confidence interval [CI] -10% to -4%; p = 0.006) and MO (-7%, 95% CI -10% to -3%; p = 0.016) from their interictal baseline as compared to the change between repeat scans in HCs (2%, 95% CI -3% to 7%). Interictally, there was a mean (standard deviation [SD]) 13% (10%) (p = 0.003) lower blood perfusion in the MA group as compared to the MO group in the foveal region (mean [SD] 0.093 [0.023] vs. 0.107 [0.021], p = 0.003). Interictal analysis also revealed higher circularity in the superficial foveal avascular zone in the MA group compared with the MO group (mean [SD] 0.686 [0.088] vs. 0.629 [0.120], p = 0.004). In addition, interictal analysis of the patients with MA or MO and unilateral headache showed increased retinal vascular parameters consistent with greater perfusion in the eye ipsilateral to the side of the pain as compared with the contralateral eye.

CONCLUSIONS

These results indicate that perfusion is reduced in MA and MO in the parafoveal retina during the ictal period. Interictally, the foveal retina in MA has reduced perfusion when compared to the foveal retina in MO. Patients with unilateral headache showed interictal asymmetry of retinal perfusion between eyes. These results indicate that changes in retinal perfusion could be a part of migraine pathophysiology, and that distinct retinal vascular signatures identified with OCTA could represent biomarkers for migraine.

Role of sensory processing sensitivity and high sensation seeking in migraine with typical aura

The psychological differences between migraine with aura (MwA) patients and healthy controls (HCs) have not been sufficiently investigated in the current scientific literature. Taking this into account, the present study aimed to examine differences between MwA patients and HCs in sensory processing sensitivity factors, high sensation seeking factors, depression, and anxiety. Mentioned variables were also used to determine their predictive role in predicting the group membership (MwA patients vs HCs). The Highly Sensitive Person Scale, the revised High Sensation Seeking Test, and the Hospital Anxiety and Depression Scale were administered to a sample of seventy-one respondents (39 MwA patients and 32 HCs). MwA patients had a significantly higher score for the low sensory threshold (sensory processing sensitivity factor) in comparison with HCs (4.36 ± 1.4 vs 3.45 ± 1.1, p = 0.003). There was no significant difference in other subscales of sensory processing sensitivity, as well as regarding the high sensation seeking, anxiety, and depression scores, between those two groups. The logistic regression model correctly classified 79.5% MwA patients and 66.7% HCs. The low sensory threshold was a statistically significant predictor for MwA patients (p = 0.001). Our results indicate a certain similarity in the brain sensitivities of MwA patients and people with sensory processing sensitivity trait. Moreover, this shows that the constructs of sensitivity in migraine patients and highly sensitive people overlap to an extent, suggesting the similarity between the conceptualization of sensitivity in the psychological literature and the conceptualization of sensitivity in the medical literature.

Cortical spreading depolarization-induced constriction of penetrating arteries can cause watershed ischemia: A potential mechanism for white matter lesions

Periventricular white matter lesions (WMLs) are common MRI findings in migraine with aura (MA). Although hemodynamic disadvantages of vascular supply to this region create vulnerability, the pathophysiological mechanisms causing WMLs are unclear. We hypothesize that prolonged oligemia, a consequence of cortical spreading depolarization (CSD) underlying migraine aura, may lead to ischemia/hypoxia at hemodynamically vulnerable watershed zones fed by long penetrating arteries (PAs). For this, we subjected mice to KCl-triggered single or multiple CSDs. We found that post-CSD oligemia was significantly deeper at medial compared to lateral cortical areas, which induced ischemic/hypoxic changes at watershed areas between the MCA/ACA, PCA/anterior choroidal and at the tip of superficial and deep PAs, as detected by histological and MRI examination of brains 2-4 weeks after CSD. BALB-C mice, in which MCA occlusion causes large infarcts due to deficient collaterals, exhibited more profound CSD-induced oligemia and were more vulnerable compared to Swiss mice such that a single CSD was sufficient to induce ischemic lesions at the tip of PAs. In conclusion, CSD-induced prolonged oligemia has potential to cause ischemic/hypoxic injury at hemodynamically vulnerable brain areas, which may be one of the mechanisms underlying WMLs located at the tip of medullary arteries seen in MA patients.

Expression of NF-κB-associated lncRNAs in different types of migraine

PURPOSE

NF-κB partakes in the pathophysiology of neurologic conditions. We quantified levels of NF-κB-associated genes in 119 patients with migraine versus healthy controls.

METHODS

We measured levels of NF-κB-associated genes in 42 patients with migraine compared with age- and sex-matched controls.

RESULTS

Comparison between patients without aura and controls revealed down-regulation of PACER [expression ratio (95% CI) 0.15 (0.06-0.36), P value < 0.0001]. Similar results were detected when comparing expression of PACER in patients with aura and controls [expression ratio (95% CI) 0.05 (0.02-0.12), P value < 0.0001]. Both DILC and CEBPA were over-expressed in patients with aura [expression ratio (95% CI) 4.9 (2.96-7.83), P value < 0.0001 and expression ratio (95% CI) 3.65 (2.39-5.24), P value < 0.0001, respectively] and in patients without aura compared with controls [expression ratio (95% CI) 3.6 (2.21-5.69), P value < 0.0001 and expression ratio (95% CI) 4.5 (2.53-7.11), P value < 0.0001, respectively]. ADINR was over-expressed in patients with aura [expression ratio (95% CI) 4.98 (3.09-8.33), P value < 0.0001] as well as patients without aura compared with controls [expression ratio (95% CI) 13.15 (7.41-23.58), P value < 0.0001]. Notably, ADINR levels were lower in patients with aura compared with patients without aura. When comparing ATG5 levels in patients with aura and controls, significant up-regulation was detected [expression ratio (95% CI) 4.4 (3.01-6.32), P value < 0.0001]. This pattern was also detected in patients without aura compared with controls [expression ratio (95% CI) 3.5 (2.28-5.35), P < 0.0001]. Finally, expression of DICER1-AS1 was elevated in patients with aura compared with patients without aura [expression ratio (95% CI) 2.47 (1.14-5.85), P = 0.03]. This lncRNA was under-expressed in patients without aura compared with controls [expression ratio (95% CI) 0.4 (0.21-1.31), P = 0.03]. CEBPA, ATG5 and ADINR had the best AUC values for distinguishing patients with aura from controls (AUC values = 0.91, 0.85 and 0.83, respectively). The AUC values for separation between patients without aura and controls were 0.90, 0.86 and 0.75 for CEBPA, ATG5 and ADINR, respectively.

CONCLUSION

Taken together, several genes in the NF-κB pathway has been revealed to be dysregulated in migraineurs and expression of these genes can be used as markers for this neurological condition.

Association of white matter hyperintensities with migraine phenotypes and response to treatment

INTRODUCTION

White matter hyperintensities (WMHs) are frequently found in migraineurs. However, their clinical significance and correlation to different migraine phenotypes and treatment responses are not well defined. The study aimed to examine the association of WMHs with migraine clinical patterns and treatment response.

AIM OF WORK

We aimed to evaluate the association between WMHs and migraine phenotypes and explore the relationship of WMHs to treatment response.

METHODS

Our cross-sectional study formed of 500 migraineurs who sought treatment in Kafr el-sheik university hospital and underwent (3 T) MRI to evaluate WMHs. Different migraine phenotypes were compared between patients with and without WMHs. According to reduced headache pain intensity and frequency, these patients were divided into treatment responder and non-responder groups.

RESULTS

A total of 145 patients (29%) had WMHs. Patients with WMHs were significantly older, had a longer disease duration, and higher attack frequency. Patients who did not respond to acute and maintenance medications had a higher frequency of WMHs and high WMHs Scheltens score. Migraine with Aura and the presence of vomiting and dizziness were predictors for the development of WMHs.

CONCLUSION

WMHs are more common in migraine with aura. It is more frequent in migraine associated with vomiting and dizziness. WMHs increased with advancing age and more severe disease burden. Poorer response to acute and prophylactic medications was found in patients with WMHs.

European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention-part 2: flunarizine

OBJECTIVE

Novel disease-specific and mechanism-based treatments sharing good evidence of efficacy for migraine have been recently marketed. However, reimbursement by insurers depends on treatment failure with classic anti-migraine drugs. In this systematic review and meta-analysis, we aimed to identify and rate the evidence for efficacy of flunarizine, a repurposed, first- or second-line treatment for migraine prophylaxis.

METHODS

A systematic search in MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Eligible trials for meta-analysis were randomized, placebo-controlled studies comparing flunarizine with placebo. Outcomes of interest according to the Outcome Set for preventive intervention trials in chronic and episodic migraine (COSMIG) were the proportion of patients reaching a 50% or more reduction in monthly migraine days, the change in monthly migraine days (MMDs), and Adverse Events (AEs) leading to discontinuation.

RESULTS

Five trials were eligible for narrative description and three for data synthesis and analysis. No studies reported the predefined outcomes, but one study assessed the 50% reduction in monthly migraine attacks with flunarizine as compared to placebo showing a benefit from flunarizine with a low or probably low risk of bias. We found that flunarizine may increase the proportion of patients who discontinue due to adverse events compared to placebo (risk difference: 0.02; 95% CI -0.03 to 0.06).

CONCLUSIONS

Published flunarizine trials predate the recommended endpoints for evaluating migraine prophylaxis drugs, hence the lack of an adequate assessment for these endpoints. Further, modern-day, large-scale studies would be valuable in re-evaluating the efficacy of flunarizine for the treatment of migraines, offering additional insights into its potential benefits.

The clinical spectrum associated with ATP1A2 variants in Chinese pediatric patients

PURPOSE

To evaluate the clinical spectrum associated with ATP1A2 variants in Chinese children with hemiplegia, migraines, encephalopathy or seizures.

METHODS

Sixteen children (12 males and 4 females), including ten patients with ATP1A2 variants whose cases had been published previously, were identified using next-generation sequencing.

RESULTS

Fifteen patients had FHM2 (familial hemiplegic migraine type 2), including three who had AHC (alternating hemiplegia of childhood) and one who had drug-resistant focal epilepsy. Thirteen patients had DD (developmental delay). The onset of febrile seizures, which occurred between 5 months and 2 years 5 months (median 1 year 3 months) was earlier than the onset of HM (hemiplegic migraine), which occurred between 1 year 5 months and 13 years (median 3 years 11 months). Disturbance of consciousness subsided first, at 40 h to 9 days (median 4.5 days); hemiplegia and aphasia were resolved slowly, taking 30 min to 6 months (median 17.5 days) for the former and 24 h to over 1 year (median 14.5 days) for the latter. Cranial MRI showed edema in the cerebral hemispheres, mainly the left hemisphereacute attacks. All thirteen FHM2 patients recovered to baseline in 30 min to 6 months. Fifteen patients had between 1 and 7 (median 2) total attacks between the baseline and follow-up timepoints. We report twelve missense variants, including a novel variant ATP1A2 variant, p.G855E.

CONCLUSIONS

The known genotypic and phenotypic spectra of Chinese patients with ATP1A2-related disorders were further expanded. Recurrent febrile seizures and DD combined with paroxysmal hemiplegia and encephalopathy should raise the clinical suspicion of FHM2. The avoidance of triggers and thus the prevention of attacks may be the most effective therapy for FHM2.

Noncausal effects between tea intake and migraine risk: a Mendelian randomization study

Observational studies have yielded conflicting results regarding the relationship between tea intake and migraine risk. Residual confounders and potential reverse causality are unavoidable in traditional observational studies. To provide evidence for establishing viable disease screening and prevention strategies, a Mendelian randomization study (MR) was conducted to determine the causal inference between tea intake and migraine. We obtained 28 single-nucleotide polymorphisms (SNPs) for any migraine (AM), 25 SNPs for migraine with aura (MA), and 27 SNPs for migraine without aura (MO) associated with tea intake derived from a large genome-wide association study (GWAS) of the UK Biobank (UKBB) (containing 447,485 samples). The largest migraine GWAS performed by the International Headache Genetics Consortium (IHGC), including 29,209 cases and 172,931 controls, provided data on migraines and their subtypes (MA and MO). We used the method of inverse variance weighting (IVW) with fixed effects as the first-string MR selection. Sensitivity analysis and MR-pleiotropy residual sum and outlier (MR-PRESSO) method further assessed the robustness of the findings. Based on the conclusion of IVW in the fixed effects model, we found that tea intake had no causal relationship with AM risk (odds ratio (OR), 0.94; 95% confidence interval (CI), 0.70-1.25; P = 0.65), MA risk (OR, 0.93; 95% CI, 0.51-1.72; P = 0.83), or MO risk (OR, 0.90; 95% CI, 0.52-1.54; P = 0.69). Sensitivity analyses and MR-PRESSO showed no directional pleiotropy or heterogeneity. Our two-sample MR investigation found no causality between tea intake and migraine risk in European populations, implying that attempts to change tea drinking habits may not lead to a reduced risk of migraine.

Mechanisms of initiation of cortical spreading depression

BACKGROUND

There is increasing evidence from human and animal studies that cortical spreading depression (CSD) is the neurophysiological correlate of migraine aura and a trigger of migraine pain mechanisms. The mechanisms of initiation of CSD in the brain of migraineurs remain unknown, and the mechanisms of initiation of experimentally induced CSD in normally metabolizing brain tissue remain incompletely understood and controversial. Here, we investigated the mechanisms of CSD initiation by focal application of KCl in mouse cerebral cortex slices.

METHODS

High KCl puffs of increasing duration up to the threshold duration eliciting a CSD were applied on layer 2/3 whilst the membrane potential of a pyramidal neuron located very close to the site of KCl application and the intrinsic optic signal were simultaneously recorded. This was done before and after the application of a specific blocker of either NMDA or AMPA glutamate receptors (NMDARs, AMPARs) or voltage-gated Ca2+ (CaV) channels. If the drug blocked CSD, stimuli up to 12-15 times the threshold were applied.

RESULTS

Blocking either NMDARs with MK-801 or CaV channels with Ni2+ completely inhibited CSD initiation by both CSD threshold and largely suprathreshold KCl stimuli. Inhibiting AMPARs with NBQX was without effect on the CSD threshold and velocity. Analysis of the CSD subthreshold and threshold neuronal depolarizations in control conditions and in the presence of MK-801 or Ni2+ revealed that the mechanism underlying ignition of CSD by a threshold stimulus (and not by a just subthreshold stimulus) is the CaV-dependent activation of a threshold level of NMDARs (and/or of channels whose opening depends on the latter). The delay of several seconds with which this occurs underlies the delay of CSD initiation relative to the rapid neuronal depolarization produced by KCl.

CONCLUSIONS

Both NMDARs and CaV channels are necessary for CSD initiation, which is not determined by the extracellular K+ or neuronal depolarization levels per se, but requires the CaV-dependent activation of a threshold level of NMDARs. This occurs with a delay of several seconds relative to the rapid depolarization produced by the KCl stimulus. Our data give insights into potential mechanisms of CSD initiation in migraine.

A causal effects of gut microbiota in the development of migraine

BACKGROUND

The causal association between the gut microbiome and the development of migraine and its subtypes remains unclear.

METHODS

The single nucleotide polymorphisms concerning gut microbiome were retrieved from the gene-wide association study (GWAS) of the MiBioGen consortium. The summary statistics datasets of migraine, migraine with aura (MA), and migraine without aura (MO) were obtained from the GWAS meta-analysis of the International Headache Genetics Consortium (IHGC) and FinnGen consortium. Inverse variance weighting (IVW) was used as the primary method, complemented by sensitivity analyses for pleiotropy and increasing robustness.

RESULTS

In IHGC datasets, ten, five, and nine bacterial taxa were found to have a causal association with migraine, MA, and MO, respectively, (IVW, all P < 0.05). Genus.Coprococcus3 and genus.Anaerotruncus were validated in FinnGen datasets. Nine, twelve, and seven bacterial entities were identified for migraine, MA, and MO, respectively. The causal association still exists in family.Bifidobacteriaceae and order.Bifidobacteriales for migraine and MO after FDR correction. The heterogeneity and pleiotropy analyses confirmed the robustness of IVW results.

CONCLUSION

Our study demonstrates that gut microbiomes may exert causal effects on migraine, MA, and MO. We provide novel evidence for the dysfunction of the gut-brain axis on migraine. Future study is required to verify the relationship between gut microbiome and the risk of migraine and its subtypes and illustrate the underlying mechanism between them.

Primary headache with onset in childhood and adolescence: natural history and prognostic factors in a Portuguese population

INTRODUCTION

Headaches are the most frequent neurological disorder in the pediatric population, with great impact on quality of life. This study aims to characterize a cohort of patients followed at a pediatric neurology unit between January 1st 2013 and December 31st, 2021.

MATERIALS AND METHODS

We reviewed medical records and selected patients with primary headaches and a minimum follow-up of 12 months.

RESULTS

A total of 226 patients were included, 54.4% female, with an average age at headache onset of 9 ± 3.5 (3.1-16.5) years; 63.5% were prepubertal. A positive family history of headache was identified in 76.6% of cases and triggers in 63.6%. At first clinical assessment, 45.1% were classified as migraine without aura, 10.6% as migraine with aura, 3.5% tension-type, 8% mixed (tension and migraine), 1.3% other type and 31.4% were unclassifiable. The patients had a median follow-up of 2.4 (1.8-3.3) years. The diagnosis of tension-type headaches remained stable in 75% of the patients and resolved in 25%; 13% of the patients with migraine without aura changed into another type of headache and 17.4% resolved; 44.4% of the patients with migraine with aura turned into another type of headache and 11.1% resolved. Of the variables studied, only duration of headache episode had a significant association with headache remission, with odds ratio 0.16 (p = 0.03; 95% confidence interval: 0.032-0.84).

CONCLUSIONS

Our study shows that headache type in pediatric population changes over time, especially in those with migraine with aura. The duration of each headache episode was presented as a predictor of headache remission over time.

Vestibular Function and Clinical Presentation of Dizziness: Are They Similar in Patients With Different Types of Migraine?

OBJECTIVE

To compare the vestibular function and clinical aspects (vestibular and migraine symptoms) of patients divided into three groups-migraine without aura, migraine with aura, and chronic migraine-and a control group by using electronystagmography and a design questionnaire.

STUDY DESIGN

Case-control study.

SETTING

Tertiary referral center.

PATIENTS

Women aged between 18 and 55 years diagnosed with migraine with aura, migraine without aura, or chronic migraine according to the International Classification of Headache Disorders ICHD-third edition; diagnosis was made by a headache specialist. The control group consisted of patients' family members and hospital employees without a personal history of headache.

MAIN OUTCOME MEASURES

Application of a questionnaire regarding vestibular symptoms and their relation to migraine aspects. Assessment of the vestibular function by electronystagmography.

RESULTS

This study evaluated 120 female patients. Dizziness was the most prevalent vestibular symptom in all the migraine groups, with higher prevalence in the episodic migraine with aura and chronic migraine groups. Phonophobia and photophobia during vestibular symptoms also had greater prevalence in the latter groups. Electronystagmography tests did not reveal differences among the groups, but clinical stratification showed that tests with mixed etiology abnormalities were more prevalent in the episodic migraine with aura and chronic migraine groups.

CONCLUSION

The prevalence of vestibular symptoms in the migraine groups and the etiology of vestibular impairment highlight that migraine affects the vestibular system. Our findings suggest that symptom progression and vestibular impact are related to migraine chronicity and presence of aura.

The gain of function SCN1A disorder spectrum: novel epilepsy phenotypes and therapeutic implications

Brain voltage-gated sodium channel NaV1.1 (SCN1A) loss-of-function variants cause the severe epilepsy Dravet syndrome, as well as milder phenotypes associated with genetic epilepsy with febrile seizures plus. Gain of function SCN1A variants are associated with familial hemiplegic migraine type 3. Novel SCN1A-related phenotypes have been described including early infantile developmental and epileptic encephalopathy with movement disorder, and more recently neonatal presentations with arthrogryposis. Here we describe the clinical, genetic and functional evaluation of affected individuals. Thirty-five patients were ascertained via an international collaborative network using a structured clinical questionnaire and from the literature. We performed whole-cell voltage-clamp electrophysiological recordings comparing sodium channels containing wild-type versus variant NaV1.1 subunits. Findings were related to Dravet syndrome and familial hemiplegic migraine type 3 variants. We identified three distinct clinical presentations differing by age at onset and presence of arthrogryposis and/or movement disorder. The most severely affected infants (n = 13) presented with congenital arthrogryposis, neonatal onset epilepsy in the first 3 days of life, tonic seizures and apnoeas, accompanied by a significant movement disorder and profound intellectual disability. Twenty-one patients presented later, between 2 weeks and 3 months of age, with a severe early infantile developmental and epileptic encephalopathy and a movement disorder. One patient presented after 3 months with developmental and epileptic encephalopathy only. Associated SCN1A variants cluster in regions of channel inactivation associated with gain of function, different to Dravet syndrome variants (odds ratio = 17.8; confidence interval = 5.4-69.3; P = 1.3 × 10-7). Functional studies of both epilepsy and familial hemiplegic migraine type 3 variants reveal alterations of gating properties in keeping with neuronal hyperexcitability. While epilepsy variants result in a moderate increase in action current amplitude consistent with mild gain of function, familial hemiplegic migraine type 3 variants induce a larger effect on gating properties, in particular the increase of persistent current, resulting in a large increase of action current amplitude, consistent with stronger gain of function. Clinically, 13 out of 16 (81%) gain of function variants were associated with a reduction in seizures in response to sodium channel blocker treatment (carbamazepine, oxcarbazepine, phenytoin, lamotrigine or lacosamide) without evidence of symptom exacerbation. Our study expands the spectrum of gain of function SCN1A-related epilepsy phenotypes, defines key clinical features, provides novel insights into the underlying disease mechanisms between SCN1A-related epilepsy and familial hemiplegic migraine type 3, and identifies sodium channel blockers as potentially efficacious therapies. Gain of function disease should be considered in early onset epilepsies with a pathogenic SCN1A variant and non-Dravet syndrome phenotype.

Meta-analytical evidence of functional and structural abnormalities associated with pain processing in migraine patients: An activation likelihood estimation

BACKGROUND

Migraine is a primary headache disorder that causes debilitating throbbing pain. Several functional MRI (fMRI) and voxel-based morphometry (VBM) studies have been used to investigate the structural and functional alteration in migraine. Here, we aim to study the converged brain regions of functional and structural abnormalities in gray matter volume (GMV) associated with pain processing and management in migraineurs and healthy controls (HC).

METHODS

A systematic search through PubMed and Sleuth was carried out for peer-reviewed functional and structural neuroimaging studies on migraine patients and HC yielded a total of 1136 studies. We performed an activation likelihood estimation (ALE) meta-analysis on VBM and pain stimulation task-based fMRI studies to investigate the converged areas of GMV and functional abnormalities between migraineurs and HC. We performed two subgroup analyses between migraine with aura (MwA) and migraine without aura (MwoA) relative to HC, and between chronic migraine (CM) and episodic migraine (EM) compared to HC.

RESULTS

The total sample included 16 fMRI and 22 VBM studies, consisting of 1295 migraine patients, compared to 995 HC. In fMRI analysis, ALE maps for pain stimulation tasks revealed hyperactivation in migraineurs in the substantia nigra compared to HC, whereas hypoactivation was seen in the cerebellum. For the VBM analysis, ALE clusters of increased GMV in migraineurs were observed in the parahippocampus and putamen nucleus. Whereas clusters of reduced GMV in migraineurs were seen in the frontal gyri. Compared to HC, MwoA patients showed a GMV reduction in the insula, and anterior cingulate, whereas MwA patients showed GMV reduction in the cerebellum, cingulate gyrus, and insula. CM patients showed decreased GMV in the precentral gyrus, whereas EM patients showed decreased GMV in the parahippocampus, and inferior frontal gyrus when compared to HC.

CONCLUSIONS

Our findings represent a potential biomarker for the diagnosis and management of migraine, by showing clustered brain regions of abnormal patterns of activation and GMV changes between migraineurs and HC which might be associated with hyposensitivity to pain in migraineurs. Further studies are required to determine disease progression or therapeutic interventions' effect on migraine.

Cerebral Hemodynamics, Right-to-Left Shunt and White Matter Hyperintensities in Patients with Migraine with Aura, Young Stroke Patients and Controls

Background: Migraine with aura (MA) patients present an increased risk of cerebrovascular events. However, whether these patients present an increased white matter hyperintensities (WMHs) load compared to the general population is still under debate. Our study aimed to evaluate the relationship between cerebral hemodynamics, right-to-left shunt (RLS) and WMHs in MA patients, young patients with cryptogenic stroke or motor transient ischemic attack (TIA) and controls. Methods: We enrolled 30 MA patients, 20 young (<60 years) patients with cryptogenic stroke/motor TIA, and 10 controls. All the subjects underwent a transcranial Doppler bubble test to detect RLS and cerebral hemodynamics assessed by the breath holding index (BHI) for the middle (MCA) and posterior (PCA) cerebral arteries. Vascular risk factors were collected. The WMHs load on FLAIR MRI sequences was quantitatively assessed. Results: The stroke/TIA patients presented a higher prevalence of RLS (100%) compared with the other groups (p < 0.001). The MA patients presented a higher BHI compared with the other groups in the PCA (p = 0.010) and higher RLS prevalence (60%) than controls (30%) (p < 0.001). The WMHs load did not differ across groups. BHI and RLS were not correlated to the WMHs load in the groups. Conclusions: A preserved or more reactive cerebral hemodynamics and the presence of a RLS are likely not involved in the genesis of WMHs in MA patients. A higher BHI may counteract the risk related to their higher prevalence of RLS. These results need to be confirmed by further studies to be able to effectively identify the protective role of cerebral hemodynamics in the increased RLS frequency in MA patients.

Acute ischemic stroke or migraine with aura? Triage considerations

ABSTRACT

This article discusses the complex relationship between acute ischemic stroke and migraine with aura, and critical nursing interventions.

Next-generation sequencing identified a novel CACNA1A I1379F variant in a familial hemiplegic migraine type 1 pedigree: A case report

RATIONALE

Familial hemiplegic migraine (FHM) is a rare, autosomal dominant migraine with aura. CACNA1A encodes the α1A subunit of P/Q-type voltage-gated calcium channels, and its mutations have been associated with a wide spectrum of episodic and chronic neurological disorders, including FHM type 1 (FHM1).

PATIENT CONCERNS

A Chinese girl and some of her relatives who presented with hemiplegia with or without migraine were found to carry a novel heterozygous missense variant, I1379F, in CACNA1A by whole-exome sequencing. The variant consegregated with the disease and was predicted to be pathogenic.

DIAGNOSIS

The patient was diagnosed with FHM1 clinically and genetically.

INTERVENTIONS

Prophylactic therapy with flunarizine 5 mg daily was prescribed to the patient.

OUTCOMES

Therapy with flunarizine was terminated after a few weeks. The intensity of the attacks was the same as before.

LESSONS

This case indicates that FHM should be considered when a patient manifests with episodic hemiplegia without migraine. In addition, genetic testing is an indispensable method to identify atypical attacks of hemiplegic migraine.

Symptomatic Migraine with Prolonged Visual Aura and Unruptured Occipital Arteriovenous Malformation

A 35 year-old woman had a two-year history of recurrent headache with clinical presentations of visual aura in her left visual field followed by right-sided throbbing headache. The patient suffered from a similar attack but her visual aura-like symptoms persisted for over 48 hours. The concurrent electroencephalogram demonstrated focal non-epileptiform rhythmic slow waves in the right occipital region. The magnetic resonance images showed prominent parenchymal edema in the right occipital area. The cerebral angiographic study proved a small cerebral arteriovenous malformation. This illustrated case showed that cerebral arteriovenous malformation produces headaches mimicking migraine with visual aura. The acute vascular flow change and the parenchymal edema trigger a prolonged visual aura with coinstantaneous evidence of cortical depression shown on the electroencephalogram. Keywords: Symptomatic migraine; Prolonged visual aura; Unruptured arteriovenous malformation.

Cortical excitability in migraine: Contributions of magnetic resonance imaging

Migraine is characterized by symptoms related to cortical hyperexcitability such as photophobia, phonophobia, osmophobia and allodynia. One-third of migraineurs experience aura, whose neurophysiological substrate is thought to be cortical spreading depression (CSD). Functional magnetic resonance imaging (MRI) has shown the migraine aura to be characterized by cerebral hyperactivity/hyperperfusion followed by hypometabolism/hypoperfusion spreading along the occipital cortex with the same spatiotemporal organization as the experimentally triggered CSD. The link between migraine aura and headache remains undetermined. Neuroimaging studies have failed to show a leakage of the blood-brain barrier, which was suspected to occur during CSD and to cause the stimulation of trigeminal nociceptive receptors. However, recent studies have highlighted the involvement of neuroglial inflammation and other studies have suggested that a common central network plays a role in the link between CSD and migraine pain. Finally, MRI has made it possible to study the contribution of metabolites such as glutamic acid, γ-amino-butyric acid and sodium in the pathophysiology of hyperexcitability in migraine.

Neuronal plumes initiate spreading depolarization, the electrophysiologic event driving migraine and stroke

In this issue of Neuron, Parker et al. discover neuronal plumes of glutamate release that initiate spreading depolarization, the electrophysiologic event underlying migraine. Mice with human migraine mutations express spontaneous and frequent plumes, which may explain the propensity to develop migraine attacks and the increased stroke risk in migraine-susceptible brains.

The electrophysiological footprint of CACNA1A disorders

Objectives

CACNA1A variants underlie three neurological disorders: familial hemiplegic migraine type 1 (FHM1), episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6). EEG is applied to study their episodic manifestations, but findings in the intervals did not gain attention up to date.

Methods

We analyzed repeated EEG recordings performed between 1994 and 2019 in a large cohort of genetically confirmed CACNA1A patients. EEG findings were compared with those of CACNA1A-negative phenocopies. A review of the related literature was performed.

Results

85 EEG recordings from 38 patients (19 EA2, 14 FHM1, 5 SCA6) were analyzed. Baseline EEG was abnormal in 55% of cases (12 EA2, 9 FHM1). The most common finding was a lateralized intermittent slowing, mainly affecting the temporal region. Slowing was more pronounced after a recent attack but was consistently detected in the majority of patients also during the follow-up. Interictal epileptic discharges (IEDs) were detected in eight patients (7 EA2,1 FHM1). EEG abnormalities and especially IEDs were significantly associated with younger age at examination (16 ± 9 vs 43 ± 21 years in those without epileptic changes, p = 0.003) and with earlier onset of disease (1 (1–2) vs 12 (5–45) years, p = 0.0009). EEG findings in CACNA1A-negative phenocopies (n = 15) were largely unremarkable (p = 0.03 in the comparison with CACNA1A patients).

Conclusions

EEG abnormalities between attacks are highly prevalent in episodic CACNA1A disorders and especially associated with younger age at examination and earlier disease onset. Our findings underpin an age-dependent effect of CACNA1A variants, with a more severe impairment when P/Q channel dysfunction manifests early in life.

Epilepsy, status epilepticus, and hemiplegic migraine coexisting with a novel SLC4A4 mutation

BACKGROUND

Recessive mutations in the SLC4A4 gene cause a syndrome characterised by proximal renal tubular acidosis (pRTA), mental retardation, dental and ocular abnormalities, and hemiplegic migraine. Rare cases involving the development of epilepsy or its severe complication-status epilepticus-have been described.

METHODS

The clinical and genetic status of four affected members in a Spanish family was studied. The SLC4A4 gene mutation was detected with a next-generation sequencing (NGS) panel in the proband, and Sanger confirmed the putative mutations in affected relatives. In silico analysis was performed to elucidate the putative effect of mutation on the splicing process.

RESULTS

A novel mutation, c.2562+2T>G, was identified in the homozygous state in all diseased members of the family. This mutation affected a canonical splice site and is predicted to abolish the wild-type donor site, which predicts a premature truncated NBCe1 protein with cotransport activity. The resulting protein lacks the 190 amino acids of the carboxyl-terminus, and the effect is likely to be a loss of function. All patients suffered from severe pRTA and ocular abnormalities, and the adults also suffered from neurological complications, such as hemiplegic migraine and/or epilepsy. Two developed life-threatening status epilepticus, although they fully recovered and remained free of seizures with valproate.

CONCLUSION

These results expand the clinical and mutational spectra of SLC4A4-related disease and have implications for understanding the potential role of NBCe1 in the pathophysiologic processes of hemiplegic migraine and epilepsy/status epilepticus associated with the mutation.

Ictal-Interictal Comparison of FDG-PET Findings in Sporadic Hemiplegic Migraine

PURPOSE

Sporadic hemiplegic migraine (SHM) is characterized by a prolonged motor aura that accompanies a migraine attack, and its underlying pathophysiology remains unclear. Functional image during the event can help to explore the mechanism.

CASE REPORT

We report a finding of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in a 15-year-old female with SHM. She presented with recurrent right arm weakness and pain with migrainous headache. A video electroencephalogram showed no evidence of epilepsy during the events. Subtraction of ictal-interictal FDG-PET coregistered to magnetic resonance imaging was performed for the image analysis. In comparison with the interictal state, the FDG-PET image showed decreased glucose metabolism in the bilateral dorsal lateral frontal cortices and bilateral occipital cortices, whereas increased metabolism in the left precentral motor cortex and right premotor cortex.

CONCLUSION

These findings reveal an increase in metabolism in the motor cortex during general cortical dysfunction in the frontal and occipital cortices in SHM. Key words: FDG-PET, hemiplegic migraine, migraine, positron emission tomography, SISCOM.

Neurology Concepts: Young Women and Ischemic Stroke-Evaluation and Management in the Emergency Department

OBJECTIVE

Ischemic stroke is a leading cause of morbidity and mortality worldwide. While the incidence of ischemic stroke is highest in older populations, incidence of ischemic stroke in adults has been rising particularly rapidly among young (e.g., premenopausal) women. The evaluation and timely diagnosis of ischemic stroke in young women presents a challenging situation in the emergency department, due to a range of sex-specific risk factors and to broad differentials. The goals of this concepts paper are to summarize existing knowledge regarding the evaluation and management of young women with ischemic stroke in the acute setting.

METHODS

A panel of six board-certified emergency physicians, one with fellowship training in stroke and one with training in sex- and sex-based medicine, along with one vascular neurologist were coauthors involved in the paper. Each author used various search strategies (e.g., PubMed, PsycINFO, and Google Scholar) for primary research and reviewed articles related to their section. The references were reviewed and evaluated for relevancy and included based on review by the lead authors.

RESULTS

Estimates on the incidence of ischemic stroke in premenopausal women range from 3.65 to 8.9 per 100,000 in the United States. Several risk factors for ischemic stroke exist for young women including oral contraceptive (OCP) use and migraine with aura. Pregnancy and the postpartum period (up to 12 weeks) is also an important transient state during which risks for both ischemic stroke and cerebral hemorrhage are elevated, accounting for 18% of strokes in women under 35. Current evidence regarding the management of acute ischemic stroke in young women is also summarized including use of thrombolytic agents (e.g., tissue plasminogen activator) in both pregnant and nonpregnant individuals.

CONCLUSION

Unique challenges exist in the evaluation and diagnosis of ischemic stroke in young women. There are still many opportunities for future research aimed at improving detection and treatment of this population.

[Altered cortical and subcortical local coherence in migraine with and without aura:evidence from resting-state fMRI]

OBJECTIVE

To compare the interictal spontaneous brain activity between migraine without aura (MwoA) patients, Migraine with visual aura (MA) patients and healthy control subjects in order to provide further insights into the complex migraine pathophysiology.

METHODS

Twenty-three eligible MwoA patients, twelve MA patients who were treated in the neurology clinics in the Second Hospital of Hebei Medical University from March to October 2014 and twenty-five gender-, age- and education- matched healthy volunteers participated in this study.After demographic and clinical characteristics were acquired, a 3.0-T MRI system was used to obtain rfMRI.ReHo method was applied to analyze the synchronization of the BOLD signal in the same time series among neighboring voxels of the brain.

RESULTS

Compared with healthy controls, MwoA patients showed significant decreases in ReHo values in the right thalamus, right putamen, right prefrontal lobe and right hippocampus (P<0.05); while MA patients showed significant decreases in ReHo values in the right thalamus, right putamen, right cerebellum and brainstem, whereas a significant increase in ReHo values in the right occipital lobe (P<0.05). Furthermore, compared with MA patients, increased ReHo values in the right cerebellum and brainstem were shown in the MwoA group (P<0.05).

CONCLUSIONS

The results suggest that the resting-state abnormalities of these regions may be associated with functional impairments in pain processing in migraine.Specifically, the results of brain regions may reflect both the similarities and differences of pathophysiological mechanisms relative to the major subtypes of migraine.

Incidences of aortic and mitral valve strands in patients with migraine with aura

OBJECTIVE

To analyze the potential association between valvular strands and migraine with aura.

METHODS

During a 1-year period,transesophageal echocardiography was performed in 51 consecutive patients with migraine with aura and 75 control subjects who underwent transesophageal echocardiography for other purposes and had no history of migraine. The presence of aortic and mitral valve strands was evaluated.

RESULTS

The incidence of valvular strands was 21.5% (11/51) in migraine patients and 28.0% (21/75) in control subjects (Χ²=0.663, P=0.416). The incidence of patent foramen ovale was significantly higher in patients with migraine with aura than in control subjects (50.9% vs.29.3%) (Χ²=6.302, P=0.012). The incidence of aortic valve strands was significantly higher than that of mitral valve strands in migraine patients (Χ²=4.320,P=0.038).

CONCLUSION

Valvular strands are not associated with migraine with aura and show little clinical significance.

Headaches during pregnancy

Among primary headaches, migraine is the form more sensitive to the ovarian hormonal milieu. Migraine without aura (MO) benefits from the hyperestrogenic state of pregnancy and the lack of hormonal fluctuations, while migraine with aura (MA) presents distinctive features. Indeed, a very strong improvement of MO has been documented across gestation, and only a minority of pregnant women still suffers during the third trimester. On the other hand, fewer women with MA report improvement or remission, and new onset of aura may be observed during pregnancy. After delivery, breastfeeding exerts a protective action on migraine recurrence. The persistence of migraine during gestation seems to affect neonatal outcomes, and several studies indicate a link between migraine and an increased risk of developing gestational hypertension/preeclampsia and other vascular complications.

A homolog of FHM2 is involved in modulation of excitatory neurotransmission by serotonin in C. elegans

The C. elegans eat-6 gene encodes a Na(+), K(+)-ATPase alpha subunit and is a homolog of the familial hemiplegic migraine candidate gene FHM2. Migraine is the most common neurological disorder linked to serotonergic dysfunction. We sought to study the pathophysiological mechanisms of migraine and their relation to serotonin (5-HT) signaling using C. elegans as a genetic model. In C. elegans, exogenous 5-HT inhibits paralysis induced by the acetylcholinesterase inhibitor aldicarb. We found that the eat-6(ad467) mutation or RNAi of eat-6 increases aldicarb sensitivity and causes complete resistance to 5-HT treatment, indicating that EAT-6 is a component of the pathway that couples 5-HT signaling and ACh neurotransmission. While a postsynaptic role of EAT-6 at the bodywall NMJs has been well established, we found that EAT-6 may in addition regulate presynaptic ACh neurotransmission. We show that eat-6 is expressed in ventral cord ACh motor neurons, and that cell-specific RNAi of eat-6 in the ACh neurons leads to hypersensitivity to aldicarb. Electron microscopy showed an increased number of synaptic vesicles in the ACh neurons in the eat-6(ad467) mutant. Genetic analyses suggest that EAT-6 interacts with EGL-30 Galphaq, EGL-8 phospholipase C and SLO-1 BK channel signaling to modulate ACh neurotransmission and that either reduced or excessive EAT-6 function may lead to increased ACh neurotransmission. Study of the interaction between eat-6 and 5-HT receptors revealed both stimulatory and inhibitory 5-HT inputs to the NMJs. We show that the inhibitory and stimulatory 5-HT signals arise from distinct 5-HT neurons. The role of eat-6 in modulation of excitatory neurotransmission by 5-HT may provide a genetic explanation for the therapeutic effects of the drugs targeting 5-HT receptors in the treatment of migraine patients.

Biological science of headache channels

Several episodic neurological diseases, including familial hemiplegic migraine (FHM) and different types of epilepsy, are caused by mutations in ion channels, and hence classified as channelopathies. The classification of FHM as a channelopathy has introduced a new perspective in headache research and has strengthened the idea of migraine as a disorder of neural excitability. Here we review recent studies of the functional consequences of mutations in the CACNA1A and SCNA1A genes (encoding the pore-forming subunit of Ca(V)2.1 and Na(V)1.1 channels) and the ATPA1A2 gene (encoding the alpha(2) subunit of the Na(+)/K(+) pump), responsible for FHM1, FHM3, and FHM2, respectively. These studies show that: (1) FHM1 mutations produce gain-of-function of the Ca(V)2.1 channel and, as a consequence, increased glutamate release at cortical synapses and facilitation of induction and propagation of cortical spreading depression (CSD); (2) FHM2 mutations produce loss-of-function of the alpha(2) Na(+)/K(+)-ATPase; and (3) the FHM3 mutation accelerates recovery from fast inactivation of Na(V)1.5 channels. These findings are consistent with the hypothesis that FHM mutations share the ability to render the brain more susceptible to CSD, by causing excessive synaptic glutamate release (FHM1) or decreased removal of K(+) and glutamate from the synaptic cleft (FHM2) or excessive extracellular K(+) (FHM3).

Genetics of headaches

Insight into the molecular mechanisms involved in primary headaches is important to identify drug targets for improving treatment of patients, but essentially lacking. Genetic research is increasingly successful in pinpointing these mechanisms. Most progress has been made for Familial Hemiplegic Migraine, a rare subtype of migraine with aura. Three genes (CACNA1A, ATP1A2 and SCN1A) have been identified that all encode ion transporters. Cellular and transgenic mouse studies suggest that neuronal hyperexcitability and increased susceptibility to cortical spreading depression, the correlate of migraine aura, are important molecular mechanisms in migraine. Investigating monogenic diseases in which migraine is a prominent feature such as CADASIL, which is caused by mutations in the NOTCH3 gene, can help understanding the pathology of migraine. Candidate gene association studies and linkage studies in the common forms of migraine were less successful. Except for the MTHFR gene no gene variant has been identified yet. Convincingly demonstrated genetic findings in other primary headaches such as cluster headache and tension-type headache are even rarer. However, with current technical possibilities of massive genotyping and international efforts to collect large well-phenotyped patient cohorts, the first gene variants for various primary headache types are likely to be discovered in the coming decade.

[Case of sporadic hemiplegic migraine with cerebellar ataxia]

A 34-year-old man was admitted with his unsteady gait, difficulty in speech and a paroxysmal severe headache accompanied with sensori-motor disturbance of the right extremities and aphasic symptom. His family history was unremarkable. His unsteadiness has progressed very slowly from childhood. He noted to be inarticulate at the age of 18 years. At the age of 33 years, he suddenly had an attack of severe throbbing headache, which was mainly left parietal, with nausea and photophobia. During the headache, his right extremities were paralyzed and he became aphasic. He had lost a partial memory of the event All these symptoms had gone within 24 hours. Thereafter, the same headache occurred about once a month. Neurological examination revealed a mild truncal ataxia and ataxic dysarthria. Electroencephalography (EEG) showed intermittent delta waves restricted over the left fronto-temporal region. Brain MRI showed a moderate atrophy of superior cerebellar vermis and anterior cerebellar lobe. The diagnosis of sporadic hemiplegic migraine (SHM) with cerebellar ataxia was made. Our case was very similar to familial hemiplegic migraine (FHM) 1, of which some families are accompanied with transient amnesia, cerebellar ataxia and EEG abnormality. Although we did not detect any mutations in CACNA1A gene previously reported in FHM1, our case might share same pathogenesis with FHM1.

Isolated bilateral lateral geniculate infarction producing bow-tie visual field defects

CASE REPORT

We examined a unique case of stroke in a 29-year-old woman. Magnetic resonance imaging revealed isolated bilateral acute infarctions of the lateral geniculate bodies (LGB). Visual field testing demonstrated incongruous but homonymous bilateral visual field loss in a bow-tie configuration.

COMMENTS

Isolated bilateral damage to the LGB is a rare event. Literature review has revealed only 4 previous incidents of bilateral damage to both LGB. We present a literature review and a case of bilateral LGB infarction producing visual field defects suggestive of bilateral lateral choroidal artery involvement in an individual with classic migraine.