Persistent and Repetitive Visual Disturbances in Migraine: A Review

Beyond Pain: The Effects of OnabotulinumtoxinA Therapy on Sensitization and Interictal Symptoms in Chronic Migraine

Chronic migraine is a disease with a high burden on patients from both a working and quality of life point of view. The pathophysiology of this subtype of migraine is due to several factors, such as medication overuse. Nevertheless, the detrimental recurring of headache attacks with central and peripheral sensitization plays a central role and explains some additional symptoms complained about by these patients even in the interictal phase. OnabotulinumtoxinA is a therapy indicated for chronic migraine since it has proven to reduce peripheral sensitization, showing even efficacy on central symptoms. The aim of this narrative review is to present the current evidence regarding the effect of OnabotulinumtoxinA on sensitization and interictal symptoms.

Visual snow syndrome and its relationship with migraine

INTRODUCTION

Visual snow syndrome (VSS) is a central nervous system disorder that consists of the constant perception of small black and white dots throughout the entire visual field.

DEVELOPMENT

VSS can present from infancy to old age, with greater prevalence in the young population, and shows no difference between sexes. The diagnostic criteria include the presence of visual snow and such other visual phenomena as palinopsia, photophobia, nyctalopia, and other persistent visual phenomena. The pathophysiology of VSS is unknown, but hyperexcitability of the visual cortex and a dysfunction in higher-order visual processing are postulated as potential mechanisms. The prevalence of migraine among patients with VSS is high, compared to the general population, and symptoms are more severe in patients presenting both conditions. No effective treatment is available, but the drug with the best results is lamotrigine, which is recommended only in selected cases with severe functional limitation.

CONCLUSIONS

VSS is a little-known and underdiagnosed entity, but the increasing number of studies in recent years has made it possible to establish diagnostic criteria and begin studying its pathophysiology. This entity is closely related to migraine, with overlapping symptoms and probably shared pathophysiological mechanisms.

From CGRP to PACAP, VIP, and Beyond: Unraveling the Next Chapters in Migraine Treatment

Migraine is a neurovascular disorder that can be debilitating for individuals and society. Current research focuses on finding effective analgesics and management strategies for migraines by targeting specific receptors and neuropeptides. Nonetheless, newly approved calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) have a 50% responder rate ranging from 27 to 71.0%, whereas CGRP receptor inhibitors have a 50% responder rate ranging from 56 to 71%. To address the need for novel therapeutic targets, researchers are exploring the potential of another secretin family peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), as a ground-breaking treatment avenue for migraine. Preclinical models have revealed how PACAP affects the trigeminal system, which is implicated in headache disorders. Clinical studies have demonstrated the significance of PACAP in migraine pathophysiology; however, a few clinical trials remain inconclusive: the pituitary adenylate cyclase-activating peptide 1 receptor mAb, AMG 301 showed no benefit for migraine prevention, while the PACAP ligand mAb, Lu AG09222 significantly reduced the number of monthly migraine days over placebo in a phase 2 clinical trial. Meanwhile, another secretin family peptide vasoactive intestinal peptide (VIP) is gaining interest as a potential new target. In light of recent advances in PACAP research, we emphasize the potential of PACAP as a promising target for migraine treatment, highlighting the significance of exploring PACAP as a member of the antimigraine armamentarium, especially for patients who do not respond to or contraindicated to anti-CGRP therapies. By updating our knowledge of PACAP and its unique contribution to migraine pathophysiology, we can pave the way for reinforcing PACAP and other secretin peptides, including VIP, as a novel treatment option for migraines.

Insights into migraine attacks from neuroimaging

Migraine is one of the most common neurological diseases and it has a huge social and personal impact. Although head pain is the core symptom, individuals with migraine can have a plethora of non-headache symptoms that precede, accompany, or follow the pain. Neuroimaging studies have shown that the involvement of specific brain areas can explain many of the symptoms reported during the different phases of migraine. Recruitment of the hypothalamus, pons, spinal trigeminal nucleus, thalamus, and visual and pain-processing cortical areas starts during the premonitory phase and persists through the headache phase, contributing to the onset of pain and associated symptoms. Once the pain stops, the involvement of most brain areas ends, although the pons, hypothalamus, and visual cortex remain active after acute treatment intake and resolution of migraine symptoms. A better understanding of the correlations between imaging findings and migraine symptomatology can provide new insight into migraine pathophysiology and the mechanisms of novel migraine-specific treatments.

Molecular Mechanisms of Migraine: Nitric Oxide Synthase and Neuropeptides

Migraine is a common condition with disabling attacks that burdens people in the prime of their working lives. Despite years of research into migraine pathophysiology and therapeutics, much remains to be learned about the mechanisms at play in this complex neurovascular condition. Additionally, there remains a relative paucity of specific and targeted therapies available. Many sufferers remain underserved by currently available broad action preventive strategies, which are also complicated by poor tolerance and adverse effects. The development of preclinical migraine models in the laboratory, and the advances in human experimental migraine provocation, have led to the identification of key molecules likely involved in the molecular circuity of migraine, and have provided novel therapeutic targets. Importantly, the identification that vasoconstriction is neither necessary nor required for headache abortion has changed the landscape of migraine treatment and has broadened the therapy targets for patients with vascular risk factors or vascular disease. These targets include nitric oxide synthase (NOS) and several neuropeptides that are involved in migraine. The ability of NO donors and infusion of some of these peptides into humans to trigger typical migraine-like attacks has supported the development of targeted therapies against these molecules. Some of these, such as those targeting calcitonin gene-related peptide (CGRP), have already reached clinical practice and are displaying a positive outcome in migraineurs for the better by offering targeted efficacy without significant adverse effects. Others, such as those targeting pituitary adenylate cyclase activating polypeptide (PACAP), are showing promise and are likely to enter phase 3 clinical trials in the near future. Understanding these nitrergic and peptidergic mechanisms in migraine and their interactions is likely to lead to further therapeutic strategies for migraine in the future.

Visual Disturbances Spectrum in Pediatric Migraine

Migraine is a complex neurological disorder with partially unknown pathophysiological mechanisms. The prevalence in childhood ranges from 7.7% to 17.8%, thus representing the most frequent primary headache. In half of the cases, migraine is accompanied or preceded by various neurological disturbances, among which the visual aura is the best known. In literature, other conditions, such as Alice in Wonderland Syndrome and Visual Snow syndrome, are characterized by visual manifestations and are often associated with migraine. The aim of this narrative review is to describe the spectrum of visual disturbances in pediatric migraine and their pathophysiological mechanisms.

Differential Diagnosis of Visual Phenomena Associated with Migraine: Spotlight on Aura and Visual Snow Syndrome

Migraine is a severe and common primary headache disorder, characterized by pain as well as a plethora of non-painful symptoms. Among these, visual phenomena have long been known to be associated with migraine, to the point where they can constitute a hallmark of the disease itself. In this review we focus on two key visual disorders that are directly or indirectly connected to migraine: visual aura and visual snow syndrome (VSS). Visual aura is characterized by the transient presence of positive and negative visual symptoms, before, during or outside of a migraine attack. VSS is a novel stand-alone phenomenon which has been shown to be comorbid with migraine. We discuss key clinical features of the two disorders, including pathophysiological mechanisms, their differential diagnoses and best treatment practices. Our aim is to provide an aid for clinicians and researchers in recognizing these common visual phenomena, which can even appear simultaneously in patients with an underlying migraine biology.

Evaluating migraine with typical aura with neuroimaging

Objective

To provide an up-to-date narrative literature review of imaging in migraine with typical aura, as a means to understand better migraine subtypes and aura biology.

Background

Characterizing subtypes of migraine with typical aura and appreciating possible biological differences between migraine with and without aura, are important to understanding the neurobiology of aura and trying to advance personalized therapeutics in this area through imaging biomarkers. One means of doing this over recent years has been the use of increasingly advanced neuroimaging techniques.

Methods

We conducted a literature review of neuroimaging studies in migraine with aura, using a PubMed search for terms 'imaging migraine', 'aura imaging', 'migraine with aura imaging', 'migraine functional imaging' and 'migraine structural imaging'. We collated the findings of the main studies, excluding small case reports and series with n < 6, and have summarized these and their implications for better understanding of aura mechanisms.

Results

Aura is likely mediated by widespread brain dysfunction in areas involving, but not limited to, visual cortex, somatosensory and insular cortex, and thalamus. Higher brain excitability in response to sensory stimulation and altered resting-state functional connectivity in migraine sufferers with aura could have a genetic component. Pure visual aura compared to visual aura with other sensory or speech symptoms as well, may involve different functional reorganization of brain networks and additional mitochondrial dysfunction mediating more aura symptoms.

Conclusion

There is a suggestion of at least some distinct neurobiological differences between migraine with and without aura, despite the shared phenotypic similarity in headache and other migraine-associated symptoms. It is clear from the vast majority of aura phenotypes being visual that there is a particular predisposition of the occipital cortex to aura mechanisms. Why this is the case, along with the relationships between cortical spreading depression and headache, and the reasons why aura does not consistently present in affected individuals, are all important research questions for the future.

The not so hidden impact of interictal burden in migraine: A narrative review

Migraine is a highly prevalent neurological disease of varying attack frequency. Headache attacks that are accompanied by a combination of impact on daily activities, photophobia and/or nausea are most commonly migraine. The headache phase of a migraine attack has attracted more research, assessment tools and treatment goals than any other feature, characteristic, or phase of migraine. However, the migraine attack may encompass up to 4 phases: the prodrome, aura, headache phase and postdrome. There is growing recognition that the burden of migraine, including symptoms associated with the headache phase of the attack, may persist between migraine attacks, sometimes referred to as the "interictal phase." These include allodynia, hypersensitivity, photophobia, phonophobia, osmophobia, visual/vestibular disturbances and motion sickness. Subtle interictal clinical manifestations and a patient's trepidation to make plans or commitments due to the unpredictability of migraine attacks may contribute to poorer quality of life. However, there are only a few tools available to assess the interictal burden. Herein, we examine the recent advances in the recognition, description, and assessment of the interictal burden of migraine. We also highlight the value in patients feeling comfortable discussing the symptoms and overall burden of migraine when discussing migraine treatment needs with their provider.

Visual snow: A systematic review and a case series

BACKGROUND

Visual Snow Syndrome is a recently recognized neurological condition presenting, continuous, tiny dots across the entire visual field, accompanied by nyctalopia, photophobia and palinopsia that persist for months. It may be part of migraine aura spectrum, yet its definition is still questionable. Diagnostic criteria for Visual Snow Syndrome are included in the supplemental material of ICHD-3. We aimed to summarize recent data to improve the understanding of Visual Snow Syndrome.

METHODS

After presenting four new cases, we conducted a PRISMA systematic search in PubMed/MEDLINE and Embase databases using the keyword "visual snow" with specific inclusion and exclusion criteria.

RESULTS

From the 855 articles identified 30 were included for the qualitative analysis. These reports covered five aspects related to Visual Snow Syndrome: epidemiology, clinical features, comorbidities, pathophysiology, and treatment. We found limited data concerning Visual Snow Syndrome's epidemiology (one study). Clinical presentation (22 articles) and the comorbidities (migraine with aura and tinnitus most often, five reports) are described in detail. The pathophysiology of Visual Snow Syndrome is only approached with hypotheses, but several neuroimaging studies have been identified (seven articles). Treatment is based on single case reports only.

CONCLUSION

Data for Visual Snow Syndrome are few and not strong enough to support Visual Snow Syndrome as a medical identity. Further investigation is needed.

Persistent monocular visual loss in migraine patients

The relationship between migraine and vision is complex. Besides migraine aura status and persistent visual aura without infarction, recognized by International Headaches Classification 3, cases of persistent monocular alterations have been described in migraineurs. To discuss the role of migraine as a risk factor for persistent monocular visual loss. We present five new cases of persistent monocular visual loss in migraineurs, discuss the differential diagnosis and possible relationship with migraine. Five young healthy patients are reported (three women) with a history of migraine (four with visual aura), that developed persistent monocular visual defects, four during an episode of migraine with aura. All patients were submitted to an extensive investigation. In three patients the scotoma was identified on automated perimetry; one of these patients had retinal hemorrhagic lesions, with fluorescein angiography revealing an isolated retinal vasculitis. In two patients fundoscopy revealed transient cotton wools spots. Except for the patient with retinal vasculitis, etiologic investigation was not conclusive. Monocular visual loss can occur in the setting of multiple pathologies that affect the eye and related structures. Although diseases requiring emergent intervention should always be excluded, we propose migraine should be considered as a contributing factor for unexplained monocular persistent scotoma.Monocular visual loss can occur in the setting of multiple pathologies that affect the eye and related structures. Although diseases requiring emergent intervention should always be excluded, we propose migraine should be considered as a contributing factor for unexplained monocular persistent scotoma.

Clinical approach to vision loss: a review for general physicians

Visual loss describes temporary or permanent reduction in visual acuity and/or field. Its aetiology is diverse due to the contributions of the different neuro-ophthalmic structures (eye, optic nerve, and brain) to image formation and perception, but may be categorised into ocular causes (corneal, lenticular, vitreoretinal and macular) or optic neuropathies. Clinical evaluation of visual loss relies on thorough history and examination to guide further tests. In this article, we provide a practical overview of visual loss assessment for general physicians.

Age- and frequency-dependent changes in dynamic contrast perception in visual snow syndrome

Objective

Patients with visual snow syndrome (VSS) suffer from a debilitating continuous (“TV noise-like”) visual disturbance. They report problems with vision at night and palinopsia despite normal visual acuity. The underlying pathophysiology of VSS is largely unknown. Currently, it is a clinical diagnosis based on the patient’s history, an objective test is not available. Here, we tested the hypothesis that patients with VSS have an increased threshold for detecting visual contrasts at particular temporal frequencies by measuring dynamic contrast detection-thresholds.

Methods

Twenty patients with VSS were compared to age-, gender-, migraine- and aura-matched controls in this case-control study. Subjects were shown bars randomly tilted to the left or right, flickering at six different frequencies (15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz). The contrast threshold (CT) for detection of left or right tilt was measured in a two-alternative adaptive forced-choice procedure (QUEST). The threshold was defined as the Michelson contrast necessary to achieve the correct response in 75% of the cases.

Results

The CT increased for higher flicker frequencies (ANOVA: main effect frequency: F (5,180) = 942; p < 0.001), with an additional significant frequency*diagnosis interaction (ANOVA: F (5,180) = 5.00; p < 0.001). This interaction effect was due to an increased CT at a flicker frequency of 15 Hz in the VSS cohort (VSS: MC = 1.17%; controls: MC = 0.77%). At the other frequencies, group comparisons revealed no differences. Furthermore, in the VSS cohort we observed an increase of CT with higher age (r = 0.69; p < 0.001), which was not seen in controls (r = 0.30; p = 0.20).

Conclusions

This study demonstrates a lower visual contrast sensitivity exclusively at 15 Hz in VSS patients and demonstrates frequency-dependent differences in dynamic contrast vision. The peak sensitivities of both parvo- and magnocellular visual pathways are close to a frequency of about 10 Hz. Therefore, this frequency seems to be of crucial importance in everyday life. Thus, it seems plausible that the impairment of contrast sensitivity at 15 Hz might be an important pathophysiological correlate of VSS. Furthermore, the overall age-related decrease in contrast sensitivity only in VSS patients underscores the vulnerability of dynamic contrast detection in VSS patients. Dynamic CT detection seems to be a promising neurophysiological test that may contribute to the diagnosis of VSS.

Schankin C, Straube A. Visual Phenomena Associated With Migraine and Their Differential Diagnosis

BACKGROUND

Visual phenomena are of many different kinds; their differential diagnosis is usually possible with directed history-taking. In this review, we describe common visual phenomena that must be distinguished from a migraine aura.

METHODS

This review is based on publications retrieved by a selective search in PubMed and the Web of Knowledge/Science, with special attention to the current classification of the International Headache Society and the recommendations of the German Migraine and Headache Society. The following search terms were used: "visual phenomena/phenomenon," "migraine aura," and "persistent/complication/ long-lasting/ongoing."

RESULTS

The most helpful questions for differential diagnosis are whether the symptoms are present in one eye only or in both, whether their onset was sudden or over minutes or days, and whether the phenomenon has occurred only once or repeatedly, or is persistently present. A visual aura associated with migraine must be distinguished, in rare cases, from an isolated epileptic aura, from cerebral/retinal ischemia, or from visual snow. Further differential diagnoses include a persisting perceptual disturbance after hallucinogen use (HPPD, "hallucinogen persisting perception disorder") and the Charles Bonnet syndrome (CBS); the latter arises as a consequence of severely impaired vision. Posterior reversible encephalopathy syndrome (PRES) is rare and generally reveals itself over its further course through the appearance of additional clinical manifestations. Primary ophthalmological causes can usually be readily identified and classified by ophthalmological examination.

CONCLUSION

Patients with visual phenomena typically consult physicians from various medical specialties. A correct differential diagnosis can be made based on the history if the physician views the symptoms in their overall context to determine the particular disease entity that is responsible.

Visual snow syndrome and its relationship with migraine

INTRODUCTION

Visual snow syndrome (VSS) is a central nervous system disorder that consists of the constant perception of small black and white dots throughout the entire visual field.

DEVELOPMENT

VSS can present from infancy to old age, with greater prevalence in the young population, and shows no difference between sexes. The diagnostic criteria include the presence of visual snow and such other visual phenomena as palinopsia, photophobia, nyctalopia, and other persistent visual phenomena. The pathophysiology of VSS is unknown, but hyperexcitability of the visual cortex and a dysfunction in higher-order visual processing are postulated as potential mechanisms. The prevalence of migraine among patients with VSS is high, compared to the general population, and symptoms are more severe in patients presenting both conditions. No effective treatment is available, but the drug with the best results is lamotrigine, which is recommended only in selected cases with severe functional limitation.

CONCLUSIONS

VSS is a little-known and underdiagnosed entity, but the increasing number of studies in recent years has made it possible to establish diagnostic criteria and begin studying its pathophysiology. This entity is closely related to migraine, with overlapping symptoms and probably shared pathophysiological mechanisms.

Maculopathy Masquerading as Migraine

We describe a case of a 23-year-old Caucasian woman with a background history of migraines who presented with bilateral paracentral scotomata. The ophthalmoscopy and MRI head were originally thought to be normal, and the scotomata were attributed to be of migrainous origin: a persistent negative aura. However, persistence of her symptoms prompted further specialist review 10 months later, at which time subtle bilateral perifoveal changes were noted, which had been apparent but overlooked at the initial assessment. Near-infrared reflectance imaging enabled better visualization of the lesions, which were apparent prior to any abnormalities on clinical examination. Spectral-domain optical coherence tomography revealed the early findings of hyperreflectivity in the outer nuclear and outer plexiform layers characteristic of acute macular neuroretinopathy. Our case aims to emphasize the importance of scrutinising ancillary tests of the macula in patients presenting with scotomata or atypical migraine symptoms, and to caution clinicians against diagnosing migraine with persistent negative aura without these investigations.

Two hundred and forty-eight cases of visual snow: A review of potential inciting events and contributing comorbidities

OBJECTIVE

To review characteristics and outcomes of all cases of visual snow seen at our institution, with attention to possible triggering events or comorbidities.

METHODS

This is a retrospective case series of patients seen at our tertiary care center from January 1994 to January 2020. Charts were reviewed if they contained the term "visual snow".

RESULTS

Of the 449 charts reviewed, 248 patients described seeing visual snow in part or all of their vision. Thirty-eight reported transient visual snow as their typical migraine aura. Of the remaining 210 patients, 89 were reported to have either an inciting event or contributing comorbidity for their visual snow symptoms, including: Post-concussion (n = 15), dramatic change in migraine or aura (n = 14), post-infection (n = 13), hallucinogen persisting perception disorder (n = 10), ocular abnormalities (n = 7), idiopathic intracranial hypertension (n = 4), neoplastic (n = 1), and posterior cortical atrophy (n = 1). Some patients had partial improvement with benzodiazepines (n = 6), lamotrigine (n = 5), topiramate (n = 3) and acetazolamide (n = 3). Presenting characteristics were similar, but patients with visual snow attributed to an inciting event or contributing comorbidity were more likely to have some improvement in their symptoms by last follow-up compared to spontaneous visual snow (p < .001).

CONCLUSIONS

Though most cases of visual snow are spontaneous, potential secondary causes should be recognized by clinicians. Patients who develop visual snow after an inciting event or related to an underlying comorbidity may have a better prognosis than those in whom it develops spontaneously. In select cases, treatment of the suspected underlying cause may significantly alleviate the otherwise typical intractable visual disturbances associated with visual snow.

Headache for ophthalmologists: current advances in headache understanding and management

Patients with headache and head pain are often referred to ophthalmologists. These symptoms can either be associated with underlying ophthalmic conditions, or more often are headache disorders unrelated to the eyes. Understanding the phenotype of the headache is critical for advice, safe discharge or onward referral. This review will provide an update on the criteria for common headache disorders that are often seen by ophthalmology and embrace disorders associated with ophthalmic diseases. It will also describe the changing management of migraine and outline recent therapies that are currently available.

Retinal disease in the neurology clinic

PURPOSE OF REVIEW

Retinal disease can manifest with visual symptoms similar to those which result from central nervous system disorders. We provide a framework for considering retinal causes of common visual complaints presenting to a neurology clinic.

RECENT FINDINGS

Technological advances have afforded quicker detection and a more thorough understanding of these retinal entities and are crucial to consider when evaluating visual complaints in the neurology clinic.

SUMMARY

It is essential to maintain a working knowledge of common retinal conditions that symptomatically overlap with common neurologic conditions. Furthermore, the ophthalmoscopic exam and retinal imaging modalities can both aid in the diagnosis and workup of visual complaints and neurologic disease.

Visual snow syndrome: a review on diagnosis, pathophysiology, and treatment

PURPOSE OF REVIEW

Visual snow is considered a disorder of central visual processing resulting in a perturbed perception of constant bilateral whole-visual field flickering or pixelation. When associated with additional visual symptoms, it is referred to as visual snow syndrome. Its pathophysiology remains elusive. This review highlights the visual snow literature focusing on recent clinical studies that add to our understanding of its clinical picture, pathophysiology, and treatment.

RECENT FINDINGS

Clinical characterization of visual snow syndrome is evolving, including a suggested modification of diagnostic criteria. Regarding pathophysiology, two recent studies tested the hypothesis of dysfunctional visual processing and occipital cortex hyperexcitability using electrophysiology. Likewise, advanced functional imaging shows promise to allow further insights into disease mechanisms. A retrospective study now provides Class IV evidence for a possible benefit of lamotrigine in a minority of patients.

SUMMARY

Scientific understanding of visual snow syndrome is growing. Major challenges remain the subjective nature of the disease, its overlap with migraine, and the lack of quantifiable outcome measures, which are necessary for clinical trials. In that context, refined perceptual assessment, objective electrophysiological parameters, as well as advanced functional brain imaging studies, are promising tools in the pipeline.

Cortical and subcortical changes following sphenopalatine ganglion blocks in chronic migraine with medication overuse headache: a preliminary longitudinal study

Objective

The purpose of this pilot study was to investigate potential changes in brain morphology (cortical thickness and cortical/subcortical volume) accompanying a series of sphenopalatine ganglion (SPG) blockade treatments in chronic migraine with medication overuse headaches (CM^w/MOH).

Background

Local anesthetization of the SPG via intranasal application is used for the treatment for multiple types of headache disorders, including CM. Our previous longitudinal fMRI study revealed improved network connectivity after such treatment. However, the impact of SPG blocks on cortical, subcortical gray matter volume and cortical thickness has yet to be assessed.

Methods

Using magnetic resonance imaging (MRI), cortical/subcortical volume were measured in 12 chronic migraine patients before and after a series of 12 SPG blocks administered over a 6-week period (2 per week). The average time between MRI assessments was 6 weeks. Targeted, within-subjects t-tests comparing pre-treatment and post-treatment values in specific apriori brain regions of interest, including the hippocampus, amygdala, basal ganglia, somatosensory cortex, temporal cortex and occipital cortex, were used to estimate the impact of repetitive SPG blocks treatment on brain morphology in CM^w/MOH.

Results

Compared to baseline values, the number of moderate/severe headache days per month, HIT-6, PHQ-9 scores and allodynia scores were all significantly improved at the end of treatment. Analysis of MRI data revealed that the volume of the right hippocampus and the right palladium significantly decreased following SPG block treatment, while the volume of the left nucleus accumbens significantly increased following treatment. Cortical thickness in the left temporal pole and left lateral occipito-temporal gyrus significantly decreased following SPG block treatment.

Conclusion

Our results suggest SPG block treatment is associated with significant symptom improvement as well as significant structural brain changes in regions known to be associated with migraine and chronic pain processing in CM^w/MOH.

Efficacy and safety of percutaneous patent foramen ovale closure devices for recurrent stroke: A systemic review and network metaanalysis

Background:

Randomized controlled trials (RCTs) that directly compare the efficacy and safety of percutaneous patent foramen ovale (PFO) closure devices have not been conducted. Thus, we performed a network meta-analysis to identify the efficacy and safety of occluder devices.

Methods:

From 1st January, 2000 to 1st May, 2018, we searched Embase, PubMed, and Cochrane Library for RCTs about percutaneous closure devices (such as STARFlex, GORE, and Amplatzer) and medical therapy for cryptogenic cerebral ischemic patients with PFO. The occurrence rate of recurrent stroke, atrial fibrillation (AF), major vascular complication (MVC), headache, transient ischemic attack, and bleeding were compared with the frequentist and Bayesian methods using R statistics.

Results:

We included 3747 patients from six RCTs. The GORE and Amplatzer occluders were found to be significantly associated with a decreased risk of recurrent stroke [relative risk (RR): 0.37 and 0.49; 95% confidence interval (CI): 0.17–0.81, 0.29–0.83, respectively]. Moreover, STARFlex was correlated to an increased risk of postoperative AF and MVCs (RR: 11.66 and 7.63; 95% CI: 4.87–21.91, 2.34–24.88).

Conclusions:

Among the three devices, the GORE and Amplatzer occluders are found to be the most effective in preventing secondary stroke in patients with PFO. Meanwhile, STARFlex is the least recommended device because it cannot decrease the risk of recurrent stroke and is the most likely to cause adverse events.

Mirtazapine for treatment of visual snow syndrome: A case series with insights into pathophysiology and therapy

Background:

Patients with visual snow syndrome (VSS) describe tiny flickering dots in the entire visual field resembling the noise of a poorly adjusted channel of analogue television with additional symptoms. Little is known about the pathophysiology and therapeutic options for this debilitating condition.

Objectives:

We present a case series of three patients with VSS taking mirtazapine, one of the most often prescribed antidepressants, and discuss the utility of antidepressants by reviewing our current understanding of pathophysiology and therapy.

Results:

Mirtazapine has no effect on VSS, neither positive nor negative. This is in line with the reports from the literature suggested only some beneficial effects from lamotrigine.

Conclusions:

Since the pathophysiology of VSS is not fully understood, we still rely on the reports of individual cases or patient series. This includes not only the positive, but also the negative results to avoid unnecessary treatment trials. Looking into the literature, antidepressants do not seem to be a solution for the visual symptoms. So far, best data exists for the anticonvulsant lamotrigine.

Reduced Visual Quality of Life Associated with Migraine is Most Closely Correlated with Symptoms of Dry Eye

BACKGROUND AND OBJECTIVE

Patients with migraine frequently report ocular or visual symptoms including aura, photophobia, and eye pain. Using validated instruments, our group previously reported that due to these symptoms, patients have marked reductions in visual quality of life. In chronic migraine, these reductions can be as substantial as those reported for other neuro-ophthalmic diseases such as multiple sclerosis with optic neuritis and idiopathic intracranial hypertension. Because the instruments take several different dimensions into account, we were unable to determine which ocular symptom(s) contributed to reduced visual quality of life. The purpose of this investigation was to attempt to determine which ocular symptom(s) were driving the observed reduction in visual quality of life.

METHODS

We designed a cross-sectional survey-based study to assess visual quality of life, headache impact, aura, dry eye, and photophobia in migraine patients. Subjects were recruited from the Headache Clinic and General Neurology Clinic at a tertiary teaching hospital. Subjects completed validated questionnaires including: The visual functioning questionnaire-25 (VFQ-25), the headache impact test (HIT-6), the visual aura rating scale (VARS), the ocular surface disease index (OSDI), and the Utah photophobia score (UPSIS-17). Associations between VFQ-25 and OSDI, VFQ-25 and VARS, VFQ-25 and UPSIS-17, HIT-6 and OSDI, HIT-6 and VARS, and HIT-6 and UPSIS-17 were calculated.

RESULTS

Of the 62 patients who completed all questionnaires, 17 had episodic migraine and 45 had chronic migraine. Twenty-three patients experienced aura and 39 did not report aura. The most striking correlations were observed between the VFQ-25 and the OSDI (-0.678; P < .001), between the HIT-6 and UPSIS-17 (0.489; P < .001), and between the HIT-6 and OSDI (0.453; P < .001).

CONCLUSIONS

Dry eye seems to be the most important symptom that reduces visual quality of life and worsens headache impact. This symptom may be a form of allodynia, a well-known feature of chronic migraine. Photophobia appears to have modest effects on headache impact. In the future, we hope to determine whether treatment of dry eye symptoms can improve visual quality of life and reduce headache impact.

More Than Meets the Eye: The Eye and Migraine-What You Need to Know

Migraine has long been associated with disturbances of vision, especially migraine with aura. However, the eye plays an important role in sensory processing as well. We have found that the visual quality of life is reduced in migraine. In this review, we discuss how the migraine and eye pain pathways are similar and affect many of the common complaints which are seen in ophthalmology and neuro-ophthalmology offices, such as dry eye and postoperative eye pain. We also review other related phenomena, including visual snow and photophobia, which also are related to altered sensory processing in migraine.

Treating status migrainosus in the emergency setting: what is the best strategy?

INTRODUCTION

Migraine is a disabling primary headache disorder with unknown exact pathomechanism. Status migrainosus (SM) is a complication of migraine (with or without aura), representing an attack that lasts for more than 72 h. There is a paucity of data published with regard to its pathomechanism and therapeutic options.

AREAS COVERED

The authors review the literature on SM from PubMed published between 1999 and January 2018. The authors specifically look at the therapeutic possibilities of SM in the emergency department in patients that have or have not already been treated with serotonergic agents. Additional discussion is given to the rare complications of migraine.

EXPERT OPINION

SM is a devastating condition; therefore, the primary goal is to prevent its development with proper acute and prophylactic migraine medication. If this treatment fails, the patient should be treated in the emergency setting. Due to the severity of the condition, parenteral pharmacotherapy is recommended. However, high-quality randomized trials are lacking. The currently available data suggest the use of intravenous fluids, corticosteroids, magnesium sulfate, anticonvulsive drugs, nonsteroidal anti-inflammatory drugs, antiemetics, and serotonergic agents for the treatment of SM. Still, there is a need for personalized and causal therapy for migraine sufferers.

The role of visual system in migraine

The visual system is involved in different ways in migraine. Visual auras are the most common form of migraine aura. It may consist of positive or negative visual symptoms and cortical spreading depression is felt to be the phenomenon that underlies it. Even in migraine without aura, vision it is not totally excluded given that one of the major criteria for the diagnosis of migraine is photophobia. In persistent visual aura, patients refer symptoms defined as visual snow and television static. In retinal migraine unilateral decreased vision or complete visual loss occurs. Ophthalmoplegic migraine is characterized by palsy of one among the three ocular motor nerves. Migraine visual aura, particularly when occurring without headache, is a diagnosis of exclusion. Imaging studies and laboratory tests should exclude neurologic disease, included seizures and central nervous system tumor, ocular pathologies, carotid or cardiac disease, thrombosis and connective tissue disease.

Visual snow in a paediatric patient

CASE REPORT

The case is presented of an 11 year-old girl referring to a one year history of photophobia and continuously seeing white spots in both eyes. The patient had a visual acuity of unity in both eyes, and a normal eye examination, and was referred to the Neuro-ophthalmology Unit. Once complete laboratory and imaging tests ruled out the possibility of any neurological pathology, she was diagnosed with visual snow (VS).

DISCUSSION

VS is an isolated symptom, possibly part of the migraine aura, that is referred by patients reporting numerous and constant white dots moving in the visual field of BE. It can significantly interfere with patient's daily activities by altering their quality of life, and ending up as a misdiagnosis. Paediatric patients also present a diagnostic challenge due to the complex interpretation that the presence of VS involves in them.