Interictal eye movement alterations in migraine with aura: impact of perceptual and cognitive load during reading

Abstract

Background

Migraine with aura (MwA) is a common neurological disorder often accompanied by visual and cognitive difficulties, including impaired attention and reading. Although previous studies have examined oculomotor function in migraine using specific and highly controlled paradigms, findings have been mixed, and eye movements during more natural tasks like reading remain understudied. The aim of this study was to explore interictal characteristics of eye movements in individuals with MwA during reading under increased cognitive and perceptual load.

Methods

This study recruited 40 MwA patients and 30 age- and sex-matched healthy controls (HCs). MwA patients were tested during their interictal phase. Participants read short texts presented on an external monitor, consisting of six slides with varying background colors and contrast ratio, while their eye movements were recorded. The obtained data, including fixation and saccade parameters, were analyzed using a MANOVA, followed by non-parametric tests (Mann–Whitney U and Wilcoxon signed-rank tests).

Results

Results indicated a trend of impairments in eye-tracking parameters in MwA patients, which was most pronounced at the end of the reading session on the slide with the lowest contrast ratio, and manifested as lower fixation and saccade frequencies and longer average fixation durations. Further analysis of individual slides revealed consistent within-group differences in the MwA group, with patients showing poorer performance on most eye-tracking parameters on colored slides compared to white, a pattern not observed in HCs.

Conclusion

This study reveals subtle eye movement imprairments in MwA patients during demanding reading tasks, particularly with colored backgrounds. These findings suggest that increased cognitive and perceptual load disproportionately impacts the visual system in MwA. Such delicate oculomotor dysfunctions could serve as observable markers for visual processing deficits in the interictal phase, and could guide a more personalized approach for a certain MwA subtype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-025-02171-4.

Introduction

Migraine is one of the most prevalent neurological disorders, characterized with varying symptomatology and interictal burden [1]. Cognitive functioning in individuals with migraine is often affected, particularly in the domains of visual processing, concentration, and comprehension of written material [2–5]. Moreover, visual disturbances in migraine with aura (MwA) are commonly associated with visual aura, the most prominent manifestation of visual impairment, along with other related symptoms such as photophobia, palinopsia, and visual snow [6, 7].

Beyond the specific aura-related visual phenomena, a particularly compelling question is whether MwA is associated with more fundamental visual deficits, especially in the domain of eye movement control, such as saccadic and smooth pursuit movements. For instance, a study using electronystagmography found that migraine patients exhibited both hypometric and hypermetric saccadic inaccuracies compared to healthy controls (HCs), although saccadic latencies and peak velocities did not differ significantly between the groups [8]. Similarly, research on smooth pursuit in migraine patients without aura during the interictal phase revealed no differences in saccadic frequency or velocity gain, but did report an altered phase relative to HCs [9]. Further evidence of subtle oculomotor abnormalities comes from a study that analyzed interictal saccadic latency distributions and found that migraine patients exhibited reduced variability in reaction times and a lower incidence of early saccades compared to controls [10].

However, a horizontal pursuit investigation of a sinusoidal target and reflexive saccades under various visual background conditions (solid gray, sinusoidal grating, and random noise) found no differences between migraine patients (with and without aura) and HCs [11]. These findings were supported by another study, which also reported no differences in reflexive saccade parameters between groups [12]. Nevertheless, in the same study, migraine patients showed increased latencies in an anti-saccade task, requiring the suppression of a reflexive response and the generation of a voluntary saccade in the opposite direction. These findings suggest that more cognitively demanding tasks may be better suited to revealing subtle oculomotor differences associated with migraine. Supporting this notion, a study employing three challenging paradigms observed increased variability in saccadic latencies during reflexive tasks among migraine patients suggesting impaired visual attention [13].

Although certain colors are thought to help ease migraine discomfort [14], there is evidence that some colors are perceived as particularly aversive or appear to worsen migraine symptoms. For instance, a study investigating background color manipulation (hue and saturation, with luminance held constant) for high-contrast text found that individuals with migraine tend to avoid reddish colors, describing them as the least comfortable [15]. However, the range of colors that tend to worsen migraine symptoms seems to be broader, as it was found that white, blue, amber, and red lights exacerbated headaches in a large number of migraine patients during the ictal phase [16, 17].

While previous studies have explored oculomotor function in migraine through specialized paradigms, often focusing on reflexive and voluntary saccades or smooth pursuit, relatively little attention has been given to eye movements during common visual tasks encountered in daily life, such as reading. To our knowledge, no study has specifically examined the characteristics of eye movements in migraine patients during reading in the interictal phase. This represents a notable gap, especially considering suggestions from prior research that certain oculomotor features may serve as potential clinical markers relevant to migraine diagnosis and monitoring. Building on this gap, and given the inconsistent findings regarding eye movement parameters, we sought to determine whether more demanding reading conditions might reveal subtle but meaningful group differences. In alignment with previous research [12] demonstrating that cognitively challenging tasks can expose latent impairments in migraine, a relatively complex text was selected that was presented to the subjects. We further increased reading difficulty by presenting the text on highly saturated colors, thereby reducing contrast and making the text harder to read. This dual manipulation, involving both the content of the text and its visual presentation, was intended to elevate cognitive and perceptual load and thus increase the likelihood of detecting differences between patients with episodic MwA and HCs.

Methods

Participants

A total of 40 MwA patients were recruited from the Headache Center at the Neurology Clinic, University Clinical Center of Serbia. The inclusion criteria included only participants without neurological, psychiatric, cardiovascular, or metabolic disorders, who were native speakers of Serbian with normal or corrected-to-normal vision. Only individuals who were migraine-free and medication-free for at least three days prior to and on the day of testing were included. Additionaly, all MwA participants were followed up after testing via electronic questionnaires, and no migraine attacks were reported within the 72 h following the experimental session. The control group consisted of 30 HCs matched for age, sex, and education level. Their health status was confirmed through brief physical and neurological examinations to rule out any neurological (with the exception of possible infrequent tension-type headache during their lifetime) or chronic systemic conditions. HCs were also screened for personal migraine occurrence, as well as migraine in their parents and siblings, and only those with a negative personal and family history were included in the study. Additional information on subjects, including clinical features, is presented in the Supplementary Materials, Table S1.

Ethical approval for the study was obtained from the Scientific Ethics Committee of the Clinical Center of Serbia and the Neurology Clinic (reference number: 23–690). The research was carried out in full accordance with the Declaration of Helsinki. All participants gave their written informed consent prior to taking part in the study.

Procedures

Stimulus presentation and data acquisition were conducted using a Lenovo ThinkPad Edge E530c laptop computer, which was connected to an external keyboard and 21.5 in LED monitor (AOC E2270SW) used by participants. Below the external monitor, an SMI RED-m 120-Hz portable remote eye tracker (iMotions, Copenhagen, Denmark) was positioned. To minimize head movement, an adjustable chin-rest was employed. Stimulus presentation was carried out using Experiment Centre 3.7 SMI software, while data collection was performed using iViewRED-m, and BeGaze 3.7 was used for data analysis and visualization. The experimental material consisted of five slides, each presenting a consecutive portion of the article about Bitcoin formatted as a six-line paragraph in black text (Times New Roman, 22pt). We selected a text about Bitcoin because of its specificity and the fact that most people are generally unfamiliar with the topic. As a relatively new concept, it was even less familiar at the time of this study, making it a complex and technical topic that is challenging to understand, even for well-educated readers. The background colors followed a fixed sequence: white, white, orange, white, and purple (Figure S1 in the Supplementary Materials). Colors were defined using RGB triplets, following the model used in previous research [18]. The orange background had an RGB value of [255, 128, 0], while the purple background was set to [128, 0, 255]. Both colors were presented at full opacity. The choice of these highly saturated colors was based on contrast ratios obtained by WebAIM contrast checker [19]. We implemented a gradual increase in reading difficulty by selecting an orange background with a moderate decrease in contrast ratio (8.33:1), making the text slightly harder to read, and a purple background with a substantial decrease (3.36:1), making reading more challenging. For context, black text on a white background has a contrast ratio of 21:1, and the minimum acceptable contrast according to Web Content Accessibility Guidelines (WCAG) is 4.5:1 [20]. Additional information about the slide text, such as character and word counts, can be found in the Supplementary Materials (Table S2).

Prior to the experimental task, participants were introduced to the equipment and provided with a brief explanation of the procedure. They were informed that they would read a short passage presented across multiple slides and instructed to read silently at their own pace. After completing each slide, they were to press the spacebar to advance to the next. Participants were seated in front of an external monitor with their heads stabilized using a chin rest and one hand placed on the spacebar of an external keyboard. The chair height was adjusted to ensure proper alignment and comfort. The distance from the monitor was approximately 70 cm, corresponding to a visual angle of approximately 0.635 degrees for the 22pt font height, considering font size on a 21.5-inch monitor (1920 × 1080 resolution, 476.64 × 268.11 mm active screen area). Prior to data collection, a four-point calibration and validation procedure was performed and repeated as needed to ensure optimal accuracy. Deviations slightly above 1° of visual angle were considered acceptable. Detailed descriptive statistics on calibration accuracy and tracking ratio are provided in Supplementary Materials, Table S3. After calibration, participants read on-screen instructions reiterating the task and explaining that the upcoming text would describe what Bitcoin is and how it functions. During the task, the experimenter sat behind and to the left of the participant, outside the participant’s visual field, and monitored the session to provide assistance if necessary. The mean recording time was 219 s (range: 124–319 s). When including the setup and instruction period, each session lasted approximately 10 min per participant.

Data processing

In total, eight eye-tracking parameters were extracted from the SMI system: fixation count, fixation frequency, total fixation duration, average fixation duration, saccade count, saccade frequency, total saccade duration, and average saccade duration.

Fixation count refers to the total number of fixations within a given time window, area of interest, or data segment. Usually, a higher number of fixations overall is considered an indication of more difficult text and less efficient visual search [21, 22]. Fixation frequency (also termed fixation rate) is defined as the number of fixations divided by the observation period in seconds, expressed in units of s⁻¹. Fixation rate is closely associated with reading speed [22], and evidence shows that it decreases with increasing task difficulty as well as with prolonged time on task [23–25]. Fixation duration is a positional duration measure that indicates how long the gaze remains at a specific location. Total fixation duration refers to the cumulative fixation time, whereas average fixation duration represents the mean fixation time; both measures expressed in ms. Fixation duration increases with text difficulty [26, 27], and longer fixations indicate that participants spend relatively more time processing the information [21] and experience difficulties in retrieving information [28]. As for saccadic measures, saccade count denotes the total number of saccades within a given time window, area of interest, or data segment. Greater saccade counts, whether overall or within an AOI, may indicate that participants spent relatively more time searching for information [21] and exerted greater effort in information integration [29]. Saccade frequency (also termed saccadic rate) refers to the number of saccades per second. It has been shown that saccadic rate decreases with increasing task difficulty or mental workload [25], as well as with higher fatigue levels [30]. Saccade duration (also termed saccadic duration) refers to the time required for a saccade to move between fixations or smooth pursuit instances. Total saccade duration represents the cumulative time spent in saccades, whereas average saccade duration reflects the mean saccade time; both measures are in ms. Task difficulty and impairments in processing capacity have been shown to increase saccade duration [22].

Statistical analysis

Statistical analyses were conducted using IBM SPSS Statistics (Version 26). In the first stage of the analysis, we examined whether overall reading profiles differed between MwA and HCs by considering all eye-tracking parameters simultaneously. To this end, we conducted a multivariate analysis of variance (MANOVA) with group (MwA vs. HCs) as the fixed factor and eight eye-tracking measures, calculated for the entire text, as dependent variables. In the next stage, we compared the performance of the groups on individual slides, and finally, we examined within-group differences between colored and white slides. The normality of the distributions of the variables of interest was assessed using the Shapiro–Wilk test, and based on these results, nonparametric tests were applied, including the Mann–Whitney U test for independent samples and the Wilcoxon signed-rank test for related samples. Visualisations were created using MATLAB (Version R2023a), with raincloud plots [31] used where appropriate to illustrate distributional patterns.

Results

Clinical data

Forty MwA patients were matched with thirty HCs by age (35.88 ± 8.53 vs. 36.07 ± 8.91 years, p =.928) and sex (67.5% vs. 70.0% females, p =.824). Additionally, participants’ educational level was assessed, and no group differences were observed (χ²(1, N = 70) = 0.36, p =.546). Notably, the majority of participants in both groups had completed some form of higher education (university or college), with 77.5% in the MwA group and 83.3% among HCs.

Complete text analysis

The overall MANOVA did not reveal statistically significant group differences across the combined set of dependent variables, Wilks’ Λ = 0.87, F(8, 61) = 1.14, p =.353, η_p² = 0.13. Follow-up univariate ANOVAs suggested initial group differences (Fig. 1) with MwA exhibiting lower fixation frequency, F(1, 68) = 5.55, p =.021, η_p² = 0.075, longer average fixation duration, F(1, 68) = 4.81, p =.032, η_p² = 0.066, and lower saccade frequency, F(1, 68) = 4.56, p =.036, η_p² = 0.063. After controlling for multiple comparisons using the false discovery rate (FDR) across the eight tests, none of the effects remained statistically significant.

Fig. 1.

Violin plots of eye-tracking parameters showing initial differences between MwA and HC across all text stimuli

To explore potential relationships between eye-tracking parameters and clinical features, correlational analyses were conducted, but these did not yield significant results.

Analysis of individual slides

Initial analyses revealed group differences between MwA and HCs across multiple slides, with MwA showing lower fixation frequency, longer average and total fixation durations, lower saccade frequency, and shorter initial total saccade duration (Supplementary Materials, Table S4). Following FDR correction, only effects on Slide 5 (Purple) remained significant, with MwA displaying lower fixation frequency (U = 391.00, Z = − 2.49, p =.013), prolonged average fixation duration (U = 396.50, Z = − 2.42, p =.016), and lower saccade frequency (U = 398.50, Z = − 2.40, p =.016) relative to HCs. Although most initial differences did not survive correction, the convergence of results points to a systematic trend in the same direction, which was statistically confirmed on the final slide (Fig. 2). More information on the distributions of eye-tracking parameters for individual slides is provided in the Supplementary Materials (Table S5).

Fig. 2.

Repeated-measures raincloud plots of eye-tracking parameters across slides. Panel (A) shows fixation parameters, while panel (B) shows saccade parameters. HCs are represented in blue, and MwA in red. The plots display individual data points, distribution density, and group means (solid line). Orange small asterisks (✱) below the distributions indicate uncorrected significance, whereas black asterisks (✱) indicate p < .05 after correction for multiple comparisons

White vs. colored slides analysis

Finally, we investigated whether reading patterns differed between colored and white slides within groups, specifically examining the effect of background color in participants with MwA compared to HCs. To test this, we averaged all measures across the white slides and across the colored slides, creating two sets of data for comparison. Analysis revealed that most of the eye-tracking parameters differed significantly in the MwA group, with poorer performance on colored slides compared to white ones (Fig. 3). Regarding fixation parameters, MwA showed higher fixation counts (Z = −2.64, p =.008), lower fixation frequency values (Z = −2.53, p =.011), and prolonged total fixation duration (Z = −3.17, p =.002) on colored slides. Similar trends were observed for saccadic parameters, with MwA showing longer total saccade duration (Z = −2.78, p =.005), and longer average saccade duration (Z = −2.68, p =.007) for colored slides. Initial testing also showed MwA exibiting lower saccade frequency in colored slides, but did not survive multiple comparison correction. Among HCs, none of the eye-tracking parameters differed significantly between white and colored slides. More information on the distributions of eye-tracking parameters for white and colored slides is provided in the Supplementary Materials (Table S6).

Fig. 3.

Violin plots of selected eye-tracking parameters in MwA participants comparing white and colored slides. Panel (A) shows fixation parameters, while panel (B) shows saccade parameters. Medians are indicated by solid, and means by dashed lines. Orange small asterisks (✱) next to the names of eye-tracking parameters indicate uncorrected significance, whereas black asterisks (✱) indicate p < .05 after correction for multiple comparisons

As in the overall experiment analysis, a correlational analysis was performed to examine the relationships between eye-tracking parameters and clinical features. This analysis revealed two significant correlations. First, a significant positive correlation was found between the frequency of MwA attacks per year and average saccade duration on white slides, r(38) = 0.39, p =.012, indicating that patients experiencing more frequent attacks tend to have prolonged saccades on white slides. Second, a significant negative correlation was observed between pain intensity and average saccade duration on colored slides, r(38) = −0.33, p =.036, suggesting that patients reporting higher pain intensity exhibit shorter average saccade duration on colored slides.

Discussion

In this study, we explored the characteristics of eye movements in MwA patients during the interictal phase while reading. Previous research on eye movements in migraine has yielded inconsistent results, with some studies reporting no differences between individuals with migraine and HCs [11], while others have identified subtle impairments in oculomotor function under more cognitively demanding conditions [12, 13]. In our study, cognitive and perceptual load was increased by presenting a text with a complex topic on highly saturated backgrounds with varying contrast to examine potential impairments in eye movement patterns in individuals with MwA. Our findings revealed a subtle yet consistent trend of MwA underperforming on most eye-tracking parameters compared to HCs. Although the combined eye-tracking measures showed no significant group differences, a few preliminary differences were noted but did not survive correction for multiple comparisons. This result aligns with previous research, which also found that differences in eye-tracking parameters between individuals with migraine and HCs are often elusive and extremely subtle, only manifesting when task demands are substantially increased [12, 13].

Further insight was gained through a more detailed analysis examining performance across individual slides. Similar to the overall analysis, multiple initial differences were observed in both fixation and saccade parameters that did not remain significant after correction for multiple comparisons. Nevertheless, the final slide provided clear confirmation of the previously noted trend, with MwA exhibiting significantly lower fixation frequency, longer average fixation durations, and reduced saccade frequency. The combination of these findings suggests that MwA participants spend more time processing written text, indicating that the task becomes increasingly challenging for them over time. This pattern of differences, observed as a consistent trend throughout the experiment, culminated on the final colored slide, likely reflecting visual or attentional fatigue and strain. The analysis of colored versus white backgrounds provided additional support, with MwA showing significant impairments across most eye-tracking measures, whereas the HCs group showed no differences. Interestingly, statistical analyses also revealed deviations from normality in many of the eye-tracking measures, particularly in the MwA group. However, this is not completely unexpected, as a substantial disruption in oculomotor control, such as that triggered by colored and low contrast backgrounds in sensitive individuals, can produce skewed distributions, with values clustering toward extremes due to pronounced performance decrements. Taken together, these findings suggest that the introduction of a saturated background color and lower contrast ratio may disproportionately tax the visual system of individuals with MwA, leading to measurable impairments in both fixation and saccadic behavior.

A substantial body of research that has grown over the years supports the previously hypothesized link between visual system impairments and migraine, often reflected in abnormal functioning of the visual network [32–34]. As these insights span various methodologies and approaches, they provide a multifaceted context for understanding the eye movement abnormalities observed in the present study. For instance, resting-state functional magnetic resonance imaging study has shown that individuals with MwA exhibit significantly increased functional connectivity in the extrastriate cortex compared to both HCs and those with migraine without aura [35]. Taken together, these findings can, at least to some extent, help identify some of the underlying neural sources of the differences in fixation and saccade patterns observed in the present study. In addition, this finding potentially suggests that altered network connectivity contributes to the less efficient visual scanning and reduced dynamic visual exploration seen in MwA during demanding reading tasks.

Structural imaging provides additional support for alterations in the visual pathways associated with migraine. An MRI study reported regional volume changes in both episodic and chronic migraine, with a significant reduction in the volume of the optic chiasm in chronic migraine patients, indicating structural disruption within a key component of the visual processing system [36]. Supporting this notion, a positron emission tomography - visual evoked potential study demonstrated that despite reduced resting metabolism in the visual cortex, migraine patients showed an increased activation-to-metabolism ratio and greater visual evoked potential area under the curve, further indicating visual cortical hyperresponsiveness [37].

Interestingly, the interplay between visual processing and pain pathways has emerged as a critical area of investigation, offering further insight into the cortical hyperreactivity and altered excitability often observed in migraine. A high-resolution functional magnetic resonance imaging study of the brainstem, which employed repeated presentations of a rotating checkerboard, revealed stronger activation within the spinal trigeminal nucleus in patients with chronic migraine [38]. The authors proposed that this enhanced activation reflects a functional link between visual and pain processing systems, suggesting a hypersensitivity within this pathway that may explain why neutral visual stimuli, such as light, are often perceived as unpleasant by those suffering from migraine. Consistent with this interpretation, our findings demonstrated that the most pronounced differences in eye movement patterns were observed on colored backgrounds. Although this effect is not immediately apparent, it emerges over time, indicating a possible influence of fatigue and depletion of attentional resources, ultimately leading to a deterioration in visual scanning, particularly on highly saturated, low-contrast backgrounds. This suggests that visual properties such as color and contrast may exert a disproportionately strong influence on individuals with migraine, potentially contributing to the discomfort and altered visual behavior seen during cognitively demanding tasks.

The findings of this study carry several potential implications. For research, they highlight the utility of eye-tracking as a tool to detect subtle visual processing alterations in MwA, which could guide future studies aimed at differentiating migraine subtypes through the application of a relatively simple and cost-effective method. Specifically, eye-tracking can be used as a supportive tool to investigate the complexity of neuropathophysiological mechanisms in MwA, particularly in the domain of visual pathways. Clinically, the observed subtle impairments in visual scanning, likely resulting from fatigue and depletion of attentional resources, suggest the potential benefit of personalized strategies during interictal periods in certain MwA subtype. These strategies might include limiting exposure to highly saturated backgrounds, adjusting contrast levels to a personally comfortable setting, and selecting an appropriate reading medium or device with a high degree of visual customization.

One of the key points that inevitably emerges from the current findings is whether they can be applied to individuals with migraine without aura (MwoA). There is a substantial body of research supporting more affected visual pathways and functionality in individuals with MwA compared to MwoA, indicating stronger oculomotor problems, visual hypersensitivity, distinct visual cortex excitability and hyper-responsivity [8, 39–42]. However, research on eye-tracking indicators so far, although showing impaired performance compared with HCs, does not support differences between MwA and MwoA [12, 13]. Considering the very complex, subtle, and intricate neurological and pathophysiological mechanisms at play in MwA and MwoA, it is difficult to make any firm statement or hypothesis about whether the same deficits observed in MwA in this study would be evident in MwoA. Future studies including both groups are needed to clarify the specificity of these effects.

This study has several limitations. First stems from the fact that, to the best of our knowledge, no similar studies involving the use of eye-tracking devices in MwA during reading have been conducted. As a result, there was no prior information on expected effect sizes that could be used in the power analysis for determining the sample size. Therefore, we opted for a conventional sample size of 40 participants. Although relatively small, we believe this represents a valuable first step toward more complex and clinically relevant research on eye movement patterns in MwA. Second, our study aimed to simulate everyday reading, but it was conducted in a highly controlled, stationary laboratory setting. While this approach provides better control over confounding variables, it lacks the ecological validity and real-time data collection afforded by wearable technologies [43]. For example, the use of eye-tracking glasses could provide a more natural and mobile framework for future research, particularly relevant given the shift in reading habits from print and monitors to mobile phones and tablets. Third, due to time constraints, we did not include a condition involving reading simple text on a white background, which could have served as a true baseline for comparison with cognitively and perceptually demanding conditions. While the white-background slides in this study may be viewed as a proxy for regular reading conditions and were used for comparison with the colored ones, future studies would benefit from including a separate baseline or control task to yield more detailed insights. Finally, as our sample included only MwA participants, the generalizability of the obtained results to MwoA remains uncertain, as previously discussed, highlighting the need for further research.

Conclusion

Collectively, these findings underscore the complex neurobiological landscape of MwA, characterized by a range of structural, functional, and connectivity alterations within visual, somatosensory, and pain processing networks. Our study’s findings, which reveal differences in fixation and saccade patterns, particularly under increased cognitive and perceptual load, contribute to this growing understanding by showing how these underlying neural alterations may manifest as observable oculomotor dysfunctions during everyday tasks such as reading. This work provides further evidence that subtle impairments in visual processing pathways may emerge more clearly under challenging perceptual and cognitive conditions in individuals with MwA during the interictal phase.

Abbreviations

CI

Confidence interval

HCs

Healthy controls

MwA

Migraine with aura

MwoA

Migraine without aura

RGB

Red green blue

SMI

SensoMotoric Instruments

Authors’ contributions

VJ: Data Curation, Formal Analysis, Investigation, Visualization, Writing – Original Draft. VK: Conceptualization, Methodology, Resources, Supervision, Writing – Review & Editing. AMS: Software, Supervision, Writing – Review & Editing. IP: Conceptualization, Investigation, Resources, Writing – Review & Editing.

Funding

There are no funds related to this research paper.

Data availability

The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was approved by the Medical Ethics Committee of the Neurology Clinic, Clinical Center of Serbia (reference number: 23–690), and was conducted following the Declaration of Helsinki. Informed consent forms were completed by all the participants after receiving an explanation of the study.

Competing interests

IP serves as member of the Editorial Board of The Journal of Headache and Pain, Head of Imaging Section of the SN Comprehensive Clinical Medicine journal and as the Guest Editor in The Journal of Headache and Pain. VJ, VK and AMS have no competing interests.