The Responses to CGRP in the Territory of the Posterior Cerebral Artery in Migraine

Calcitonin gene-related peptide (CGRP) is important in trigeminovascular (TMV) sensitization with neurogenic inflammation which might be involved in CGRP-induced headache (CGRP-IH). Distribution of white matter lesions, migraine aura, and functional neuroimaging indicate that posterior circulation is especially exposed to TMV sensitization. The transcranial Doppler (TCD) is able to detect changes in the posterior cerebral artery (PCA) during CGRP stimulation. Thus, we studied CGRP-induced hemodynamic changes in PCA and frequency of CGRP-IH. Twenty healthy subjects and 20 patients with migraine participated in our study. TCD was used to monitor mean arterial velocity in posterior cerebral artery (vmPCA). Simultaneously, end-tidal carbon dioxide (Et-CO2), mean arterial pressure (MAP), and heart rate (HR) were measured. During the experiment, we monitored the frequency of CGRP-IH. We determined the values of vmPCA, Et-CO2, MAP, and HR and calculate the response of vmPCA, Et-CO2, MAP, and HR to CGRP. To test the differences and relationships, statistical methods were applied using SSPS. We found significant decrease in vmPCA in migraine and control groups and found the vmPCA response to be significantly lower in migraine (p = 0.018). Et-CO2 decreases in both groups, and it is significantly lower in migraine (p < 0.001). MAP is significantly higher in migraine (p = 0.001), while HR is not significantly higher in migraine (p = 0.570). CGRP-IH is significantly associated with vmPCA responses (p = 0.003) and migraine (p < 0.001). We concluded that hemodynamic changes in PCA are significantly related to CGRP-IH. The TMV sensitization might be pronounced in posterior circulation explaining clinical and morphologic issues in migraine.

Ebstein anomaly associated with retinal venular dilatation, migraine, and visual snow syndrome: a case report

BACKGROUND

To present a case with Ebstein anomaly, a rare congenital heart disorder, with ophthalmological and neurophthalmological signs and symptoms. To date, retinal venous dilatation and visual snow syndrome have not been previously been published in this anomaly.

CASE PRESENTATION

A 10-year-old white girl was diagnosed with Ebstein anomaly. From age 12, she regularly suffered from migraines with auras and photophobia. At age 16 she started to see short-term bouts of white snow, that after a year were present all day. At age 20, she was found to have a decreased retinal arteriovenous ratio.

CONCLUSIONS

Retinal arterial tortuosity and venular dilatation are common in congenital heart disease but have not been described in Ebstein anomaly, nor has the visual snow syndrome.

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.