Brain Processing of Visual Self-Motion Stimuli in Patients With Migraine: An fMRI Study

Cerebellar somatotopy of the trigemino-cervical complex during nociception

INTRODUCTION

The somatotopic organization of the human cerebellum processes somato-motoric input. Its role during pain perception for nociceptive input remains ambiguous. A standardized experimental trigeminal nociceptive input in functional imaging might clarify the role of the cerebellum in trigeminal nociception. Also of interest is the greater occipital nerve, which innervates the back of the head, and can influence the trigeminal perception due to functional coupling within the brainstem, forming the so-called trigemino-cervical complex.

METHODS

In our preregistered study (clinicaltrials.gov: NTC03999060), we stimulated the greater occipital as well as the three main branches of the trigeminal nerve during functional magnetic resonance imaging in two independent cohorts of young healthy volunteers without psychiatric, neurological or pain-related disorders to disentangle overlapping somatotopic cerebellar organization of the nerves innervating the human head.

RESULTS

We found a dominant effect of the first trigeminal branch in the cerebellum, underpinning its particular role for headache diseases, and somatotopic representations in bilateral cerebellar lobules I-IV, V, VIIb, VIIIa and Crus I as well as in the brainstem.

SIGNIFICANCE

The study expands the current knowledge on facial and head pain processing by the cerebellum and provides an initial somatotopic map of the trigemino-cervical complex in the human cerebellum with a predominant representation of the first trigeminal branch.

Influence of Role Expectancy on Patient-Reported Outcomes Among Patients With Migraine: A Randomized Clinical Trial

Importance

It is usually assumed that an individual's classification as a patient or a healthy person is determined by the presence or absence of disease, but little is known about whether the mere awareness of being a patient or a healthy control can play an important role for reporting outcomes.

Objective

To investigate whether assignment to the role of a patient or a healthy control has an effect on patient-reported outcomes.

Design, Setting, and Participants

This single center, double-blind, 3-group randomized clinical trial included consecutive patients from a tertiary headache clinic based at a single center in Germany who were invited to participate between October 2019 and June 2023. Statistical analysis was performed from January to March 2024.

Intervention

Patients with migraine were randomized into 2 groups. The first group was told that this study was centered on migraine symptoms, whereas the second group was told that healthy controls were being sought for a study about patients with vertigo. A third group of age- and sex-matched headache-free participants served as controls. All participants viewed 2 standardized roller coaster videos and provided ratings of their perceived levels of motion sickness and dizziness.

Main Outcomes and Measures

The primary outcome was self-reported vestibular symptoms. Secondary outcomes included differences in motion sickness, headache burden, and migraine disability. Outcomes were assessed using standardized questionnaires.

Results

The final sample included 366 participants: 122 patients with migraine assigned the role of patient (MP) (migraine as patient): mean [SD] age, 37.56 [12.93] years; 105 [86.1%] female), 122 patients with migraine assigned the role of healthy participant (MH) (migraine as healthy): mean [SD] age, 37.03 [13.10] years; 107 [87.7%] female), and 122 headache-free controls (HC): mean [SD] age, 37.55 [11.56] years; 100 [82.0%] female). The assigned role of the individuals with migraine (MP vs MH) had a significant effect on self-disclosure of (1) estimation that symptoms (dizziness) will occur under specific conditions (self-reported vestibular symptoms: 79 MP [64.8%]; 29 MH [23.8%]; 9 HC [7.4%]; P < .001), (2) the increase of such symptoms (dizziness) after viewing the roller coaster video, and (3) the reported frequency (median [IQR] self-reported monthly headache days for MP: 7 [4-15] days; for MH: 5 [2-10] days; P = .008) and severity (median [IQR] migraine disability assessment score for MP: 35 [20-64] points; for MH: 25 [11-47] points; P = .005) of migraine symptoms. Statistically significant changes were also found for self-reported headache frequency and disability caused by migraine.

Conclusions and Relevance

This randomized clinical trial found an effect of expectations regarding the role of a patient with respect to clinical and study outcomes. These findings suggest that role expectations should be taken into account when, for example, invasive treatments are discussed.

Trial Registration

ClinicalTrials.gov Identifier: NCT06322550.

Appropriate Vestibular Stimulation in Children and Adolescents-A Prerequisite for Normal Cognitive, Motor Development and Bodily Homeostasis-A Review

The structural development of the vestibular part of the inner ear is completed by birth but its central connections continue to develop until adolescence. Their development is dependent on vestibular stimulation-vestibular experience. Studies have shown that vestibular function, modulated by experience and epigenetic factors, is not solely an instrument for body position regulation, navigation, and stabilization of the head and images but also influences cognition, emotion, the autonomous nervous system and hormones. To emphasize the importance of appropriate vestibular stimulation, we present a literature review of its effect on bodily homeostasis, cognition and emotion.

Network Meta-analysis of Different Treatments for Vestibular Migraine

INTRODUCTION

Although one of the major presentations of vestibular migraine is dizziness with/without unsteady gait, it is still classified as one of the migraine categories. However, in contrast to ordinary migraine, vestibular migraine patients have distinct characteristics, and the detailed treatment strategy for vestibular migraine is different and more challenging than ordinary migraine treatment. Currently, there is no conclusive evidence regarding its management, including vestibular migraine prophylaxis.

AIM

The objective of this current network meta-analysis (NMA) was to compare the efficacy and acceptability of individual treatment strategies in patients with vestibular migraine.

METHODS

The PubMed, Embase, ScienceDirect, ProQuest, Web of Science, ClinicalKey, Cochrane Central, and ClinicalTrials.gov databases were systematically searched for randomized controlled trials (RCTs), with a final literature search date of 30 December 2022. Patients diagnosed with vestibular migraine were included. The PICO of the current study included (1) patients with vestibular migraine; (2) intervention: any active pharmacologic or non-pharmacologic intervention; (3) comparator: placebo-control, active control, or waiting list; and (4) outcome: changes in migraine frequency or severity. This NMA of RCTs of vestibular migraine treatment was conducted using a frequentist model. We arranged inconsistency and similarity tests to re-examine the assumption of NMA, and also conducted a subgroup analysis focusing on RCTs of pharmacological treatment for vestibular migraine management. The primary outcome was changes in the frequency of vestibular migraines, while the secondary outcomes were changes in vestibular migraine severity and acceptability. Acceptability was set as the dropout rate, which was defined as the participant leaving the study before the end of the trial for any reason. Two authors independently evaluated the risk of bias for each domain using the Cochrane risk-of-bias tool.

RESULTS

Seven randomized controlled trials (N = 828, mean age 37.6 years, 78.4% female) and seven active regimens were included. We determined that only valproic acid (standardized mean difference [SMD] -1.61, 95% confidence interval [CI] -2.69, -0.54), propranolol (SMD -1.36, 95% CI -2.55, -0.17), and venlafaxine (SMD -1.25, 95% CI -2.32, -0.18) were significantly associated with better improvement in vestibular migraine frequency than the placebo/control groups. Furthermore, among all the investigated pharmacologic/non-pharmacologic treatments, valproic acid yielded the greatest decrease in vestibular migraine frequency among all the interventions. In addition, most pharmacologic/non-pharmacologic treatments were associated with similar acceptability (i.e. dropout rate) as those of the placebo/control groups.

CONCLUSIONS

The current study provides evidence that only valproic acid, propranolol, and venlafaxine might be associated with beneficial efficacy in vestibular migraine treatment.

TRIAL REGISTRATION

CRD42023388343.

Balance alterations are associated with neck pain and neck muscle endurance in migraine

BACKGROUND

Migraine patients may present with both cervical and balance dysfunctions. The neck plays an important role in balance by providing substantial proprioceptive input, which is integrated in the central nervous system and influences the balance control systems. Whether balance and neck dysfunctions are associated in patients with migraine is still to be explored.

OBJECTIVES

This study aimed to assess the association between the sensory organization test of balance with neck pain features, cervical strength, endurance, and range of motion in patients with migraine.

METHODS

Sixty-five patients with migraine underwent the sensory organization test assessed with the Equitest-Neurocom® device. Maximum voluntary isometric contraction, cervical flexion and extension range of motion, and cervical flexor and extensor endurance were assessed. In addition, the features of migraine and neck pain were collected. Patients were dichotomized according to cut-off scores of balance performance and the association between outcomes were explored.

RESULTS

Patients with reduced balance performance presented a higher frequency of migraine (p = 0.035), a higher frequency of aura (p = 0.002), greater neck pain intensity (p = 0.013), and decreased endurance of cervical flexors (p = 0.010) and extensors (p < 0.0001). The total balance score was correlated with age (r = -0.33; p = 0.007), migraine frequency (r = -0.29; p = 0.021), neck pain intensity (r = -0.26; p = 0.038), and endurance of the cervical flexors (r = 0.39; p = 0.001) and extensors (r = 0.36; p = 0.001). Migraine frequency, neck pain intensity, and endurance of the cervical flexors can predict 21% of the sensory organization test variability.

CONCLUSION

Neck pain features and endurance of the cervical muscles are related to reduced balance performance in patients with migraine. These results shed light to a better understanding of balance alterations in migraine patients.

Balance disorders and migraine

BACKGROUND

Migraine is associated with motion sensitivity symptoms such as kinetosis, vestibular symptoms and balance alterations. While focus is given to headache management, addressing these symptoms is often neglected, although they are related to additional migraine burden and increased disability.

PURPOSE

Our aim is to disseminate the current understanding of the motion sensitivity symptoms among patients with migraine, with focus on balance impairments. We discuss the susceptibility of migraine to motion sensitivity, its suggested mechanisms, the balance alterations during quiet standing, mobility tasks and reactions to external perturbations. The role of migraine subdiagnosis, implications for clinical practice and future perspectives are also acknowledged.

IMPLICATIONS

Balance disorders are one of the signs reflecting a broader and complex spectrum of motion sensitivity, which are present even between attacks. Migraineurs are especially inherent to these symptoms probably due to brain hyperexcitability and to shared pathophysiological mechanisms. Patients, especially with aura and chronic migraine, exhibit balance instability during quiet standing under different surface and visual input conditions. Migraineurs demonstrated reduced limits of stability and lower performance on walk, transposing obstacles and sit to stand tasks. Only patients with aura present impairment of motor control reactions following external perturbations. Balance alterations are associated with falls and are influenced by aura, migraine frequency and psychosocial aspects, but not by vestibular symptoms or vestibular migraine diagnosis. There is a high demand for high quality of evidence regarding the assessment and care of motion sensitivity symptoms in migraineurs, considering approaches to manage not just the pain, but its associated symptoms.

Functional magnetic resonance imaging in migraine: A systematic review

BACKGROUND

Migraine is a highly prevalent primary headache disorder. Despite a high burden of disease, key disease mechanisms are not entirely understood. Functional magnetic resonance imaging is an imaging method using the blood-oxygen-level-dependent signal, which has been increasingly used in migraine research over recent years. This systematic review summarizes recent findings employing functional magnetic resonance imaging for the investigation of migraine.

METHODS

We conducted a systematic search and selection of functional magnetic resonance imaging applications in migraine from April 2014 to December 2021 (PubMed and references of identified articles according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines). Methodological details and main findings were extracted and synthesized.

RESULTS

Out of 224 articles identified, 114 were included after selection. Repeatedly emerging structures of interest included the insula, brainstem, limbic system, hypothalamus, thalamus, and functional networks. Assessment of functional brain changes in response to treatment is emerging, and machine learning has been used to investigate potential functional magnetic resonance imaging-based markers of migraine.

CONCLUSIONS

A wide variety of functional magnetic resonance imaging-based metrics were found altered across the brain for heterogeneous migraine cohorts, partially correlating with clinical parameters and supporting the concept to conceive migraine as a brain state. However, a majority of findings from previous studies have not been replicated, and studies varied considerably regarding image acquisition and analyses techniques. Thus, while functional magnetic resonance imaging appears to have the potential to advance our understanding of migraine pathophysiology, replication of findings in large representative datasets and precise, standardized reporting of clinical data would likely benefit the field and further increase the value of observations.

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.

Prevalence and risk factors of migraine headache among university students: A cross-sectional study in Lebanon

Background Migraine constitutes a major public health concern since it negatively affects both the quality of life and the productivity of patients. Migraine among students can cause impaired academic performance and limit their daily activities. Objective This study aims to assess the prevalence of migraine among university students using the ID Migraine screening tool and to evaluate risk factors associated with migraine. Methods A cross-sectional study was performed over a period of six months targeting 1144 university students recruited from the different faculties. Results Migraine was suggested in 35.8% of subjects based on ID-Migraine. Migraine prevalence was significantly higher among women (42% versus 23.3% of men). After adjusting for covariates, women, daily coffee consumption, having unorganized meals, eating fast food and fasting were the main predictors of migraine.  Almost 41% of migraine students had a family history of migraine and only 26.7% sought medical help. Interestingly, most of the migraine students (84.8%) took headache medications without referring them to their doctor. Conclusion Recognizing headache risk factors among migraine students and adopting lifestyle changes accordingly can be an effective strategy to prevent the chronification of the attacks, decrease headache frequency and improve patients’ quality of life.

Effect of Visually Induced Motion Sickness from Head-Mounted Display on Cardiac Activity

Head-mounted display (HMD) virtual reality devices can facilitate positive experiences such as co-presence and deep immersion; however, motion sickness (MS) due to these experiences hinders the development of the VR industry. This paper proposes a method for assessing MS caused by watching VR content on an HMD using cardiac features. Twenty-eight undergraduate volunteers participated in the experiment by watching VR content on a 2D screen and HMD for 12 min each, and their electrocardiogram signals were measured. Cardiac features were statistically analyzed using analysis of covariance (ANCOVA). The proposed model for classifying MS was implemented in various classifiers using significant cardiac features. The results of ANCOVA reveal a significant difference between 2D and VR viewing conditions, and the correlation coefficients between the subjective ratings and cardiac features have significant results in the range of -0.377 to -0.711 (for SDNN, pNN50, and ln HF) and 0.653 to 0.677 (for ln VLF and ln VLF/ln HF ratio). Among the MS classification models, the linear support vector machine achieves the highest average accuracy of 91.1% (10-fold cross validation) and has a significant permutation test outcome. The proposed method can contribute to quantifying MS and establishing viewer-friendly VR by determining its qualities.