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Background: It is still debatable whether the mechanisms underlying photophobia are related to altered visual cortex excitability or specific abnormalities of colour-related focal macular retino-thalamic information processing. Methods: This cross-sectional study examined Ganzfeld blue-red (B-R) and blue-yellow (B-Y) focal macular cone flash ERG (ffERG) and focal-flash visual evoked potentials (ffVEPs) simultaneously in a group of migraine patients with (n = 18) and without (n = 19) aura during the interictal phase, in comparison to a group of healthy volunteers (HVs) (n = 20). We correlate the resulting retinal and cortical electrophysiological responses with subjective discomfort from exposure to bright light verified on a numerical scale. Results: Compared to HVs, the amplitude and phase of the first and second harmonic of ffERG and ffVEPs were non-significantly different in migraine patients without aura and migraine patients with aura for both the B-R and the B-Y focal stimuli. Pearson's correlation test did not disclose correlations between clinical variables, including the photophobia scale and electrophysiological variables. Conclusions: These results do not favour interictal functional abnormalities in L-M- and S-cone opponent visual pathways in patients with migraine. They also suggest that the discomfort resulting from exposure to bright light is not related to focal macular retinal-to-visual cortex pathway. [ABSTRACT FROM AUTHOR]

Background: To date, a number of studies on migraine have cross-sectionally evaluated sensory sensitivity with aversion thresholds/scores along the migraine cycle, reporting a decreased tolerance to sensory stimuli in different sensory modalities. Our hypothesis was that patients with migraine would exhibit heightened sensitivity to sound, light, touch and smell on days where they reported greater headache intensity. Methods: This is an exploratory, longitudinal study, carried out over the course of 27 days. Aversion thresholds or scores to sound, light, touch and smell were quantified in six patients with migraine (11.33 ± 6.53 headache days/month). Results: Patients reported an increased sensitivity to light (p adj = 0.0297), touch (p adj = 0.0077), and smell (padj = 0.0201) on days with higher headache intensity. However, a greater sensitivity to sound on days with higher headache intensity was only reported when anxiety levels were high (p adj = 1.4e−06). Interestingly, variable levels of tolerance to bothersome light over time can also influence the correlation between light sensitivity and headache intensity (p adj = 1.4e−06). Conclusions: Based on the present findings, future longitudinal studies evaluating sensory threshold changes along the migraine cycle in patients with migraine should account for the increased tolerance to bothersome light over time as well as the effect of anxiety on auditory sensitivity. [ABSTRACT FROM AUTHOR]

Background: Clinical trials on anti-calcitonin gene-related peptide monoclonal antibodies poorly investigated their impact on migraine accompanying symptoms. Objective: To evaluate the impact of basal accompanying symptoms on anti-CGRP monoclonal antibodies treatment response and their evolution after six months of treatment in migraine patients. Methods: Patients with migraine diagnosis seen in the Headache Clinic and treated with erenumab, galcanezumab or fremanezumab were prospectively recruited. They completed a daily eDiary which provided data on headache frequency and the following accompanying symptoms of each day: photophobia, phonophobia, nausea, dizziness, and aura. Patients were classified as responders or non-responders based on 50% or greater reduction in headache days per month at month 6 (≥50% response rate). Accompanying symptoms ratios based on headache days per month were assessed per patient at baseline and after three and six months. Comparisons for basal characteristics, basal accompanying symptoms ratios and their evolution after six months between responders and non-responders were performed. Results: One hundred and fifty-eight patients were included, 44% (69/158) showed ≥50% response rate after six months. A significant reduction in headache days per month in both groups was found at month 6 (−9.4 days/month in ≥50% response rate group; p < 0.001, −2.2 days/month in <50% response rate group; p = 0.004). Additionally, significant decreases in photophobia (−19.5%, p < 0.001), phonophobia (−12.1%, p = 0.010) and aura ratios (−25.1%, p = 0.008) were found in ≥50% response rate group. No statistically significant reductions were found in nausea and dizziness in any group since their reduction was correlated with the decrease in headache days per month. Higher photophobia ratios at baseline were predictive of an increased response between months 3 and 6 (Incidence Risk Ratio = 0.928, p = 0.040). Conclusions: The days per month with photophobia, phonophobia and aura decreased at a higher rate than headache days per month after six months in the ≥50% response group. Higher photophobia ratios were associated with higher response rates between three and six months. It could indicate an involvement of peripheral CGRP in photophobia as well as a central modulation of migraine through these treatments which mainly act on the periphery. [ABSTRACT FROM AUTHOR]

Background and Objectives: Increased sensitivity to light and patterns is typically associated with migraine, but has also been anecdotally reported in cluster headache, leading to diagnostic confusion. We wanted to assess whether visual sensitivity is increased ictally and interictally in cluster headache. Methods: We used the validated Leiden Visual Sensitivity Scale (L-VISS) questionnaire (range 0-36 points) to measure visual sensitivity in people with episodic or chronic cluster headache: (i) during attacks; (ii) in-between attacks; and in episodic cluster headache (iii) in-between bouts. The L-VISS scores were compared with the L-VISS scores obtained in a previous study in healthy controls and participants with migraine. Results: Mean L-VISS scores were higher for: (i) ictal vs interictal cluster headache (episodic cluster headache: 11.9 ± 8.0 vs. 5.2 ± 5.5, chronic cluster headache: 13.7 ± 8.4 vs 5.6 ± 4.8; p < 0.001); (ii) interictal cluster headache vs controls (5.3 ± 5.2 vs 3.6 ± 2.8, p < 0.001); (iii) interictal chronic cluster headache vs interictal ECH in bout (5.9 ± 0.5 vs 3.8 ± 0.5, p = 0.009), and (iv) interictal episodic cluster headache in bout vs episodic cluster headache out-of-bout (5.2 ± 5.5 vs. 3.7 ± 4.3, p < 0.001). Subjective visual hypersensitivity was reported by 110/121 (91%; 9 missing) participants with cluster headache and was mostly unilateral in 70/110 (64%) and ipsilateral to the ictal pain in 69/70 (99%) participants. Conclusion: Cluster headache is associated with increased ictal and interictal visual sensitivity. In contrast to migraine, this is mostly unilateral and ipsilateral on the side of the ictal pain. [ABSTRACT FROM AUTHOR]

Background: Trigeminal autonomic cephalalgias and complex regional pain syndrome are rare conditions, and their co-occurrence has not been reported previously. Clinical findings: In two patients, ipsilateral trigeminal autonomic cephalalgias developed after the onset of upper limb complex regional pain syndrome. Hyperalgesia to thermal and mechanical stimuli extended beyond the affected limb to encompass the ipsilateral forehead, and was accompanied by ipsilateral hyperacusis and photophobia. In addition, examination of the painful limb and bright light appeared to aggravate symptoms of trigeminal autonomic cephalalgias. Detailed examination of the association between facial and upper limb pain indicated that both sources of pain cycled together. Furthermore, in one case, stellate ganglion blockade inhibited pain for an extended period not only in the affected limb but also the face. Conclusions: These findings suggest some overlap in the pathophysiology of complex regional pain syndrome and trigeminal autonomic cephalalgias. Specifically, central sensitization and/or disruption of inhibitory pain modulation on the affected side of the body in complex regional pain syndrome might trigger ipsilateral cranial symptoms and increase vulnerability to trigeminal autonomic cephalalgias. [ABSTRACT FROM AUTHOR]

Objective: There is an unexplained association between disturbed sleep and migraine. In this blinded crossover study, we investigate if experimental sleep restriction has a different effect on pain thresholds and suprathreshold pain in interictal migraineurs and controls. Methods: Forearm heat pain thresholds and tolerance thresholds, and trapezius pressure pain thresholds and suprathreshold pain were measured in 39 interictal migraineurs and 31 healthy controls after two consecutive nights of partial sleep restriction and after habitual sleep. Results: The effect of sleep restriction was not significantly different between interictal migraineurs and controls in the primary analyses. Pressure pain thresholds tended to be lower (i.e., increased pain sensitivity) after sleep restriction in interictal migraineurs compared to controls with a 48-hour preictal-interictal cut-off (p = 0.061). We found decreased pain thresholds after sleep restriction in two of seven migraine subgroup comparisons: heat pain thresholds decreased in migraineurs with lower pain intensity during attacks (p = 0.005) and pressure pain thresholds decreased in migraineurs with higher severity of photophobia during attacks (p = 0.031). Heat pain thresholds tended to decrease after sleep restriction in sleep-related migraine (p = 0.060). Sleep restriction did not affect suprathreshold pain measurements in either group. Conclusion: This study could not provide strong evidence for an increased effect of sleep restriction on pain sensitivity in migraineurs compared to healthy controls. There might be a slightly increased effect of sleep restriction in migraineurs, detectable using large samples or more pronounced in certain migraine subgroups. [ABSTRACT FROM AUTHOR]

Photophobia is one of the most common symptoms in migraine, and the underlying mechanism is uncertain. The discovery of the intrinsically-photosensitive retinal ganglion cells which signal the intensity of light on the retina has led to discussion of their role in the pathogenesis of photophobia. In the current review, we discuss the relationship between pain and discomfort leading to light aversion (traditional photophobia) and discomfort from flicker, patterns, and colour that are also common in migraine and cannot be explained solely by the activity of intrinsically-photosensitive retinal ganglion cells. We argue that, at least in migraine, a cortical mechanism provides a parsimonious explanation for discomfort from all forms of visual stimulation, and that the traditional definition of photophobia as pain in response to light may be too restrictive. Future investigation that directly compares the retinal and cortical contributions to photophobia in migraine with that in other conditions may offer better specificity in identifying biomarkers and possible mechanisms to target for treatment. [ABSTRACT FROM AUTHOR]

Objective: To assess photophobia and allodynia in subjects with post-traumatic headache and examine how these sensory hypersensitivities associate with clinical measures of disease burden. Background: Post-traumatic headache is the most frequent and disabling long-term consequence of mild traumatic brain injury. There is evidence of sensory dysfunction in acute post-traumatic headache, and it is known from other headache conditions that sensory amplifications correlate with more severe disease. However, systematic studies in post-traumatic headache are surprisingly scarce. Methods: We tested light and tactile sensitivity, along with measures of disease burden, in 30 persistent post-traumatic headache subjects and 35 controls. Results: In all, 79% of post-traumatic headache subjects exhibited sensory hypersensitivity based on psychophysical assessment. Of those exhibiting hypersensitivity, 54% exhibited both light and tactile sensitivity. Finally, sensory thresholds were correlated across modalities, as well as with headache attack frequency. Conclusions: In this study, post-traumatic headache subjects with both light and tactile sensitivity had significantly higher headache frequencies and lower sensitivity thresholds to both modalities, compared to those with single or no sensory hypersensitivity. This pattern suggests that hypersensitivity across multiple modalities may be functionally synergistic, reflect a higher disease burden, and may serve as candidate markers of disease. [ABSTRACT FROM AUTHOR]

Purpose: To define the melanopsin and cone luminance retinogeniculate pathway contributions to photophobia in healthy controls and migraineurs. Methods: Healthy controls and migraineurs were categorized according to the International Classification of Headache Disorders criteria. Photophobia was measured under full-field illumination using electromyography in response to narrowband lights spanning the melanopsin and cone luminance action spectra. Migraineurs were tested during their interictal headache-free period. Melanopsin-mediated post-illumination pupil responses quantified intrinsically photosensitive Retinal Ganglion Cell (ipRGC) function. Results: A model combining the melanopsin and cone luminance action spectra best described photophobia thresholds in controls and migraineurs; melanopsin contributions were ∼1.5× greater than cone luminance. In the illumination range causing photophobia, migraineurs had lower photophobia thresholds (∼0.55 log units; p < 0.001) and higher post-illumination pupil response amplitudes (p = 0.03) than controls. Conclusion: Photophobia is driven by melanopsin and cone luminance inputs to the cortex via the retino-thalamocortical pathway. In migraineurs, lower photophobia thresholds reflect hypersensitivity of ipRGC and cone luminance pathways, with the larger and prolonged post-illumination pupil response amplitude indicative of a supranormal melanopsin response. Our findings inform artificial lighting strategies incorporating luminaires with low melanopsin excitation and photopic luminance to limit the lighting conditions leading to photophobia. [ABSTRACT FROM AUTHOR]

Background: Calcitonin gene-related peptide is recognized as a key player in migraine, yet the mechanisms and sites of calcitonin gene-related peptide action remain unknown. The efficacy of calcitonin gene-related peptide-blocking antibodies as preventative migraine drugs supports a peripheral site of action, such as the trigeminovasculature. Given the apparent disconnect between the importance of vasodilatory peptides in migraine and the prevailing opinion that vasodilation is an epiphenomenon, the goal of this study was to test whether vasodilation plays a role in calcitonin gene-related peptide-induced light aversive behavior in mice. Methods: Systemic mean arterial pressure and light aversive behavior were measured after intraperitoneal administration of calcitonin gene-related peptide and vasoactive intestinal peptide in wild-type CD1 mice. The functional significance of vasodilation was tested by co-administration of a vasoconstrictor (phenylephrine, endothelin-1, or caffeine) with calcitonin gene-related peptide to normalize blood pressure during the light aversion assay. Results: Both calcitonin gene-related peptide and vasoactive intestinal peptide induced light aversion that was associated with their effect on mean arterial pressure. Notably, vasoactive intestinal peptide caused relatively transient vasodilation and light aversion. Calcitonin gene-related peptide-induced light aversion was still observed even with normalized blood pressure. However, two of the agents, endothelin-1 and caffeine, did reduce the magnitude of light aversion. Conclusion: We propose that perivascular calcitonin gene-related peptide causes light-aversive behavior in mice by both vasomotor and non-vasomotor mechanisms. [ABSTRACT FROM AUTHOR]

Background: Often concussion/mTBI triggers a chronic headache syndrome called persistent post-traumatic headache (P-PTH) that can last from months to years post-injury, and produce significant disruption of childhood education, social interaction and development. Although prevalent and highly disabling, P-PTH is underrepresented in headache and pain research and lacks clear definition and pathophysiology. Clinical presentation of P-PTH frequently resembles that of other headache disorders, like migraine, yet the pathophysiological mechanisms are distinct and not fully understood, making the disorder difficult to treat in the clinical setting.Methods: In a retrospective analysis of 1506 pediatric patients attending Boston Children's Hospital clinics, demographic trends, symptom features, and the influence of sex on clinical presentation of PTH are presented. We compare clinical characteristics of P-PTH with a published cohort of migraine patients to evaluate the clinical features that are unique to P-PTH.Results: Findings show that despite equivalent representation of sex in the clinic, P-PTH is expressed more in females than males and is weighted towards somatic symptoms. Relative to migraine, PTH is less associated with a family history of headache.Conclusions: The ability to identify persons with PTH can help manage risk factors and identify persons likely to develop persistent post-concussion symptoms. [ABSTRACT FROM AUTHOR]

Background: Fremanezumab, a fully humanized monoclonal antibody targeting calcitonin gene-related peptide, has demonstrated efficacy for the preventive treatment of migraine in adults. Objective: To evaluate the effect of fremanezumab treatment on acute headache medication use and migraine-associated symptoms in patients with episodic migraine. Methods: In the Phase 3 HALO trial, patients with episodic migraine were randomized to receive subcutaneous fremanezumab monthly (225 mg at baseline, weeks 4 and 8), fremanezumab quarterly (675 mg at baseline, placebo at weeks 4 and 8), or placebo over a 12-week period. The secondary endpoint was change from baseline in the monthly number of days with use of any acute headache mediation or migraine-specific acute headache medication; exploratory endpoints were change from baseline in the monthly number of days with nausea or vomiting, photophobia, or phonophobia. Results: Of 875 patients randomized, 865 were included in the analysis (monthly, n = 287; quarterly, n = 288; placebo, n = 290). Baseline mean ± standard deviation days with: Any acute headache medication use (monthly: 7.7 ± 3.4; quarterly: 7.8 ± 3.7; placebo: 7.7 ± 3.6), migraine-specific acute headache medication use (6.1 ± 3.1; 6.6 ± 3.1; 7.1 ± 3.0), nausea or vomiting (4.5 ± 3.6; 4.9 ± 3.7; 4.5 ± 3.3) and photophobia and phonophobia (5.5 ± 4.1; 6.3 ± 4.1; 6.0 ± 3.9) were similar among treatment arms. Fremanezumab reduced the number of days of acute headache medication use ([least-squares mean change vs. placebo] monthly: −1.4 [95% confidence interval: −1.84, −0.89], p < 0.001; quarterly: −1.3 [−1.76, −0.82], p < 0.001) and migraine-specific acute headache medication use (monthly: −2.2 [−2.80, −1.56], p < 0.001; quarterly: −2.2 [−2.81, −1.58], p < 0.001) compared with placebo. Fremanezumab also reduced nausea or vomiting, photophobia, and phonophobia compared with placebo. Conclusions: Fremanezumab reduced the need for acute headache medications, including migraine-specific medications, while treating migraine-associated symptoms in patients with episodic migraine. Trial registration: Clinicaltrials.gov NCT02629861 [ABSTRACT FROM AUTHOR]

Objective: To review and discuss the literature on the role of thalamic structure and function in migraine.Discussion: The thalamus holds an important position in our understanding of allodynia, central sensitization and photophobia in migraine. Structural and functional findings suggest abnormal functional connectivity between the thalamus and various cortical regions pointing towards an altered pain processing in migraine. Pharmacological nociceptive modulation suggests that the thalamus is a potential drug target.Conclusion: A critical role for the thalamus in migraine-related allodynia and photophobia is well established. Additionally, the thalamus is most likely involved in the dysfunctional pain modulation and processing in migraine, but further research is needed to clarify the exact clinical implications of these findings. [ABSTRACT FROM AUTHOR]

Background: Routine assessment of photophobia in the clinical setting may underestimate the presence and severity of this condition. We aimed to develop and validate a questionnaire to improve evaluation of the impact of photophobia on activities of daily living, and to determine the relationship of this questionnaire to psychophysical assessment of light sensitivity thresholds.Methods: We developed the 17-item Utah Photophobia Symptom Impact Scale (UPSIS-17) and compared its psychometric properties to the 8-item Korean Photophobia Questionnaire (KUMC-8). Ninety five subjects with or without light sensitivity completed both questionnaires; 72 also completed laboratory-based assessment of light sensitivity thresholds. We used Rasch analysis to evaluate instrument targeting, including internal consistency and reliability. Correlation analysis was used to assess the relationship between questionnaire scores and light sensitivity thresholds.Results: We observed correlation between UPSIS-17 and KUMC-8, r = 0.72 (p < 0.0001). Higher UPSIS-17 scores correlated with light sensitivity thresholds, r = -0.42 (p < 0.0001), whereas KUMC-8 scores did not significantly correlate with light sensitivity thresholds, r = -0.21 (p = 0.072). UPSIS-17 showed better instrument targeting than KUMC-8 on Rasch analysis. Person-item maps allowed for identification of questions that could be removed without affecting questionnaire validity measures.Conclusion: This study resulted in a shortened, 12-item questionnaire. The UPSIS-12 retained significant correlation with both the KUMC-8 and light sensitivity thresholds, yielding a simpler tool for symptom assessment, while retaining validity. This expanded tool may be useful in clinical, as well as research settings, for collection of data about disability due to photophobia. [ABSTRACT FROM AUTHOR]

Background Transcranial static magnetic field stimulation (tSMS) reduces cortical excitability in humans. Methods The objective of this study was to determine whether tSMS over the occipital cortex is effective in reducing experimental photophobia. In a sham-controlled double-blind crossover study, tSMS (or sham) was applied for 10 minutes with a cylindrical magnet on the occiput of 20 healthy subjects. We assessed subjective discomfort induced by low-intensity and high-intensity visual stimuli presented in a dark room before, during and after tSMS (or sham). Results Compared to sham, tSMS significantly reduced the discomfort induced by high-intensity light stimuli. Conclusions The visual cortex may contribute to visual discomfort in experimental photophobia, providing a rationale for investigating tSMS as a possible treatment for photophobia in migraine. [ABSTRACT FROM AUTHOR]

Background Autonomic dysfunction and light sensitivity are core features of the migraine attack. Growing evidence also suggests changes in these parameters between attacks. Though sensory and autonomic responses likely interact, they have not been studied together across the spectrum of disease in migraine. Methods We performed digital infrared pupillometry while collecting interictal photophobia thresholds (PPT) in 36 migraineurs (14 episodic; 12 chronic; 10 probable) and 24 age and sex-matched non-headache controls. Quantitative pupillary light reflexes (PLR) were assessed in a subset of subjects, allowing distinction of sympathetic vs parasympathetic pupillary function. A structured questionnaire was used to ascertain migraine diagnosis, headache severity, and affective symptoms. Results Photophobia thresholds were significantly lower in migraineurs than controls, and were lowest in chronic migraine, consistent with a disease-related gradient. Lower PPT correlated with smaller dark-adapted pupil size and larger end pupil size at PPT, which corresponded to a reduced diameter change. On PLR testing, measures of both parasympathetic constriction and sympathetic re-dilation were reduced in migraineurs with clinically severe migraine. Conclusions In summary, we show that severity of photophobia in migraine scales with disease severity, in association with shifts in pupillary light responses. These alterations suggest centrally mediated autonomic adaptations to chronic light sensitivity. [ABSTRACT FROM AUTHOR]

Background Visual after-effects are illusions that occur after prolonged viewing of visual displays. The motion after-effect (MAE), for example, is an illusory impression of motion after viewing moving displays: subsequently, stationary displays appear to drift in the opposite direction. After-effects have been used extensively in basic vision research and in clinical settings, and are enhanced in migraine. Objective The objective of this article is to assess associations between ( 1 ) MAE duration and visual symptoms experienced during/between migraine/headache attacks, and ( 2 ) visual stimuli reported as migraine/headache triggers. Methods The MAE was elicited after viewing motion for 45 seconds. MAE duration was tested for three test contrast displays (high, medium, low). Participants also completed a headache questionnaire that included migraine/headache triggers. Results For each test contrast, the MAE was prolonged in migraine. MAE duration was associated with photophobia; visual triggers (flicker, striped patterns); and migraine or headache frequency. Conclusions Group differences on various visual tasks have been attributed to abnormal cortical processing in migraine, such as hyperexcitability, heightened responsiveness and/or a lack of intra-cortical inhibition. The results are not consistent with hyperexcitability simply from a general lack of inhibition. Alternative multi-stage models are discussed and suggestions for further research are recommended, including visual tests in clinical assessments/clinical trials. [ABSTRACT FROM AUTHOR]

Background: Migraine attacks manifest with hypersensitivities to light, sound, touch and odor. Some people with migraine have photosensitivity between migraine attacks, suggesting persistent alterations in the integrity of brain regions that process light. Although functional neuroimaging studies have shown visual stimulus induced "hyperactivation" of visual cortex regions in migraineurs between attacks, whether photosensitivity is associated with alterations in brain structure is unknown.Methods: Levels of photosensitivity were evaluated using the Photosensitivity Assessment Questionnaire in 48 interictal migraineurs and 48 healthy controls. Vertex-by-vertex measurements of cortical thickness were assessed in 28 people with episodic migraine who had interictal photosensitivity (mean age = 35.0 years, SD = 12.1) and 20 episodic migraine patients without symptoms of interictal photosensitivity (mean age = 36.0 years, SD = 11.4) using a general linear model design.Results: Migraineurs have greater levels of interictal photosensitivity relative to healthy controls. Relative to migraineurs without interictal photosensitivity, migraineurs with interictal photosensitivity have thicker cortex in several brain areas including the right lingual, isthmus cingulate and pericalcarine regions, and the left precentral, postcentral and supramarginal regions.Conclusion: Episodic migraineurs with interictal photosensitivity have greater cortical thickness in the right parietal-occipital and left fronto-parietal regions, suggesting that persistent light sensitivity is associated with underlying structural alterations. [ABSTRACT FROM AUTHOR]

Background and aims: Migraine headache is one of the most common primary headache disorders and is three times more prevalent in women than in men, especially during the reproductive ages. The neurobiological basis of the female dominance has been partly established. The present study aimed to investigate the effect of gender on the headache manifestations in migraine patients. Methods: The study group consisted of 2082 adult patients from five different hospitals' tertiary care-based headache clinics. The relationship between headache characteristics and gender was evaluated in migraine with aura (MwA) and migraine without aura (MwoA). The duration, severity, frequency of headache and associated symptoms were evaluated in both genders and age-dependent variations and analyzed in two subgroups. Results: Women with migraine were prone to significantly longer duration and intensity of headache attacks. Nausea, phonophobia and photophobia were more prevalent in women. Median headache duration was also longer in women than in men in MwA (p=0.013) and MwoA (p<0.001). Median headache intensity was higher in women than in men in MwA (p=0.010) and MwoA (p=0.009). The frequency of nausea was significantly higher in women than in men in MwA (p=0.049). Throbbing headache quality and associated features (nausea, photophobia, and phonophobia) were significantly more frequent in women than in men in MwoA. The gender impact varied across age groups and significant changes were seen in female migraineurs after age 30. No age-dependent variation was observed in male migraineurs. Conclusion: Gender has an influence on the characteristics of the headache as well as on the associated symptoms in migraine patients, and this impact varies across the age groups, particularly in women. [ABSTRACT FROM AUTHOR]

The article discusses a study that compared the ictal and interictal visual sensitivity of migraineurs with aura (MWA) and without aura (MwoA) to assess the discomfort and disability experienced by migraine sufferers. The researchers examined the effectiveness of two published survey instruments, the Visual Discomfort Scale and the migraine photophobia scale and of their correlation with a physiologic measure of visual cortex functional activation.

The article presents the study which examined the prevalence, characteristics and clinical correlates of transient visual disturbances (TVD) in adolescents with headaches. The study was part of the Taitung County Adolescent Headache Survey conducted in Taiwan. The study was authorized by the Kaohsiung Medical University Hospital's Institutional Review Board.

Introduction : Increased lumbar cerebrospinal fluid (CSF) sodium has been reported during migraine. We used ultra-high field MRI to investigate cranial sodium in a rat migraine model, and simulated the effects of extracellular sodium on neuronal excitability. Methods : Behavioral changes in the nitroglycerin (NTG) rat migraine model were determined from von Frey hair withdrawal response and photography. Central sensitization was measured by counting cFos-immunoreactive cells in the trigeminal nucleus caudalis (TNC). Sodium was quantified in vivo by ultra-high field sodium MRI at 21 Tesla. Effects of extracellular sodium on neuronal excitability were modeled using NEURON software. Results : NTG decreased von Frey withdrawal threshold (p = 0.0003), decreased eyelid vertical height:width ratio (p < 0.0001), increased TNC cFos stain (p < 0.0001), and increased sodium between 7.5 and 17% in brain, intracranial CSF, and vitreous humor (p < 0.05). Simulated neurons exposed to higher sodium have more frequent and earlier spontaneous action potentials, and corresponding earlier sodium and potassium currents. Conclusions : In the rat migraine model, sodium rises to levels that increase neuronal excitability. We propose that rising sodium in CSF surrounding trigeminal nociceptors increases their excitability and causes pain and that rising sodium in vitreous humor increases retinal neuronal excitability and causes photosensitivity. [ABSTRACT FROM AUTHOR]

Introduction: Photic driving is believed to be increased in migraineurs and has been interpreted as a sign of cortical hyperexcitability. However, most previous studies have included patients in various phases of the migraine cycle. The results are, therefore, difficult to interpret as neurophysiological abnormalities tend to accumulate close to the attack in migraineurs.Subjects and Methods: We recorded steady state visual evoked EEG-responses (SSVEPs) for 6, 12, 18 and 24 Hz flash stimuli from 33 migraineurs without aura, eight migraineurs with aura and 32 healthy controls. Interictal recordings were compared pair-wise with recordings before, during and after attack, as well as with EEGs from healthy controls. Driving power was also correlated with sensory hypersensitivity and severity of migraine.Results: Between attacks, driving responses to 18 Hz and 24 Hz were attenuated in migraineurs without aura. Driving power of 12 Hz increased before the attack. Attack trigger sensitivity, photophobia, pain intensity and a family history of migraine were related to decreased and/or symmetric photic driving.Conclusions: Earlier results may have overestimated the driving response in migraine due to inclusion of recordings during the preictal interval and/or habituation among controls. Abnormal photic driving may be related to the pathophysiology of clinical sensory hypersensitivity. [ABSTRACT FROM PUBLISHER]

Photophobia is an important criterion for the diagnosis of migraine. However, several Asian epidemiological surveys about migraine have shown lesser prevalence of photophobia than that of Western studies. This discrepancy is probably caused by underestimation of photophobia due to inappropriate questioning of patients by physicians. To investigate this issue, we developed a questionnaire about photophobia and evaluated its usefulness in 103 patients with migraine. In phase 1 of the study, we found good repeatability of the questionnaire with a 0.826 κ coefficient. In phase 2, the prevalence of photophobia from interviews and that from the questionnaire were compared. The prevalence of interview-documented photophobia was 51.5% and of questionnaire-documented photophobia 82.5% ( P < 0.001). In phase 3, we attempted to make a short-form questionnaire with the same detection power of the questionnaire study. Two short-form questionnaires were identified as a useful method for detecting photophobia. The prevalence of photophobia could be underreported via interview, especially in Asian migraineurs. Using this questionnaire to test for photophobia, the diagnostic rate of photophobia and migraine could be improved. [ABSTRACT FROM AUTHOR]

Our objective was to compare the presence of self-reported unilateral photophobia or phonophobia, or both, during headache attacks comparing patients with trigeminal autonomic cephalalgias (TACs)—including cluster headache, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and paroxysmal hemicrania—or hemicrania continua, and other headache types. We conducted a prospective study in patients attending a referral out-patient clinic over 5 months and those admitted for an intramuscular indomethacin test. Two hundred and six patients were included. In episodic migraine patients, two of 54 (4%) reported unilateral photophobia or phonophobia, or both. In chronic migraine patients, six of 48 (13%) complained of unilateral photophobia or phonophobia, or both, whereas none of the 24 patients with medication-overuse headache reported these unilateral symptoms, although these patients all had clinical symptoms suggesting the diagnosis of migraine. Only three of 22 patients (14%) suffering from new daily persistent headache (NDPH) experienced unilateral photophobia or phonophobia. In chronic cluster headache 10 of 21 patients (48%) had unilateral photophobia or phonophobia, or both, and this symptom appeared in four of five patients (80%) with episodic cluster headache. Unilateral photophobia or phonophobia, or both, were reported by six of 11 patients (55%) with hemicrania continua, five of nine (56%) with SUNCT, and four of six (67%) with chronic paroxysmal hemicrania. Unilateral phonophobia or photophobia, or both, are more frequent in TACs and hemicrania continua than in migraine and NDPH. The presence of these unilateral symptoms may be clinically useful in the differential diagnosis of primary headaches. [ABSTRACT FROM AUTHOR]

Sensitivity to light was investigated 5 and 8 h after consumption of an amino acid drink which contained L-tryptophan (balanced amino acid condition: 19 controls and 22 migraine sufferers) or which produced a short-term reduction in brain serotonin synthesis by omittingl-tryptophan (tryptophan depletion condition: 16 controls and 16 migraine sufferers). Migraine sufferers reported more intense nausea, headache, glare- and light-induced pain than controls. In addition, glare- and light-induced pain were greater in the tryptophan depletion condition than in the balanced amino acid condition, in both migraine sufferers and controls. Eight hours after the amino acid drink, after participants had completed tests of pain sensitivity and motion sickness provocation, tryptophan depletion augmented headache in migraine sufferers and aggravated nausea in migraine sufferers and controls. These findings suggest that a reduction in brain synthesis of serotonin intensifies photophobia and other migrainous symptoms and thus might contribute to the pathogenesis of migraine. [ABSTRACT FROM AUTHOR]

A double-masked randomized controlled study with cross-over design compared the effectiveness of precision ophthalmic tints in the prevention of headache in migraine sufferers. Seventeen patients chose the colour of light that optimally reduced perceptual distortion of text and maximized clarity and comfort. They were later given glasses with spectral filters providing optimal colour under conventional white lighting ('optimal' tint) or glasses that provided a slightly different colour ('control' tint). The tints were supplied in random order, each for 6 weeks, separated by an interval of at least 2 weeks with no tints. Headache diaries showed that the frequency of headaches was marginally lower when the 'optimal' tint was worn, compared with the 'control'. The trial extends to adults with migraine, the results of a previous double-masked study demonstrating, in children with reading difficulty, beneficial effects of precision tints in reducing symptom frequency. In the present study, however, the effects are suggestive rather than conclusive. [ABSTRACT FROM AUTHOR]

Magnesium sulphate has been used in the acute treatment of migraines; some studies found it to be a highly effective medication in the acute control of migraine pain and associated symptoms. This randomized, double-blind, placebo-controlled study assesses the effect of magnesium sulphate on the pain and associated symptoms in patients with migraine without aura and migraine with aura. Sixty patients in each group were assigned at random to receive magnesium sulphate, 1000 mg intravenously, or 0.9% physiological saline, 10 ml. We used seven parameters of analgesic evaluation and an analogue scale to assess nausea, photophobia and phonophobia. In the migraine without aura group there was no statistically significant difference in the patients who received magnesium sulphate vs. placebo in pain relief. The analgesic therapeutic gain was 17% and number needed to treat was 5.98 at 1 h. There was also no statistical difference in relief of nausea. We did observe a significant lower intensity of photophobia and phonophobia in patients who received magnesium sulphate. In the migraine with aura group patients receiving magnesium sulphate presented a statistically significant improvement of pain and of all associated symptoms compared with controls. The analgesic therapeutic gain was 36.7% at 1 h. A smaller number of patients continued to have aura in the magnesium sulphate group compared with placebo 1 h after the administration of medication. Our data support the idea that magnesium sulphate can be used for the treatment of all symptoms in migraine with aura, or as an adjuvant therapy for associated symptoms in patients with migraine without aura. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether scalp tenderness and photophobia, two well-recognized symptoms of migraine, develop during the motion sickness induced by optokinetic stimulation. To investigate whether motion sickness has a general influence on pain perception, pain was also assessed in the fingertips. After optokinetic stimulation, nausea increased more and headache persisted longer in 21 migraine sufferers than in 15 non-headache controls. Scalp tenderness increased during optokinetic stimulation in nauseated subjects, and pain in the fingertips increased more and photophobia persisted longer in migraine sufferers than controls. These findings suggest that the disturbance responsible for nausea also sensitizes trigeminal nociceptive neurones or releases inhibitory controls on their discharge. A low nausea threshold and a propensity for sensitization to develop rapidly in nociceptive pathways may increase susceptibility to migraine. [ABSTRACT FROM AUTHOR]

We aimed to estimate primary sensory evoked potential (EP) amplitude, amplitude-intensity functions and habituation in migraine patients compared with healthy control subjects and to investigate the possible relation to check size, sound and light discomfort thresholds, and the time to the next attack. Amplitudes of cortical visual evoked potentials (VEP, check size 8' and 33'), cortical long latency auditory evoked potential (AEP NIP1; 40, 55 and 70 dB SL tones) and brainstem auditory evoked potential (BAEP wave IV-V; 40, 55 and 65 dB SL clicks) were recorded and analysed in a blind and balanced design. The difference between the response to the first and the second half of the stimulus sequence was used as a measure of habituation. Twenty-one migraine patients (16 women and five men, mean age 39.3 years, six with aura, 15 without aura) and 22 sex- and age-matched healthy control subjects were studied (18 women and four men, mean age 39.5 years). Low sound discomfort threshold correlated significantly with low levels of BAEP wave IV-V amplitude habituation (r = -0.30, P = 0.05). VEP an AEP amplitudes, habituation, and amplitude-intensity function (ASF) slopes did not differ between groups when ANOVA main factors were considered. Control group VEP habituation was found for small check stimuli (P = 0.04), while potentiation was observed for medium sized checks (P = 0.02). The eight migraine patients who experienced headache within 24 h after the test tended to have increased BAEP wave IV-V ASF slopes (P = 0.08). This subgroup did also have a significant VEP habituation to small checks (P = 0.04). No correlation was found between different modalities. These results suggest that: (i) VEP habituation/potentiation state and brainstem activatio state may depend on the attack-interval cycle in migraine; (ii) VEP habituation/ potentiation may depend on spatial stimulus frequency; (iii) phonophobia (and possibly photophobia) may depend more on subcortical (brainstem) function than on cortical mechanisms; (iv) low cortical preactivation in migraine could not be confirmed; (v) EP habituation and ASF analysis may reflect sensory modality-specific, not generalized, central nervous system states in migraine and healthy control subjects. [ABSTRACT FROM AUTHOR]

Light and sound-induced discomfort and pain thresholds were measured in 26 patients with cervicogenic headache, in 40 patients with tension-type headache, and in 100 headache-free controls. Neither headache group was significantly different as to photophobia and phonophobia, but both were significantly more sensitive to light and sound than controls (p<0.0001), even when patients were tested in the headache-tree period (p<0.05). Episodic and chronic tension-type headache had similar photo- and phonophobia thresholds (p≥0.7). Tension-type headache patients were more photo- and phonophobic during headache than outside attack (p<0.05), but this was not true for cervicogenic headache (p≥0.56). In cervicogenic headache patients, photophobia (p<0.05) but not phonophohia (p=0.28) was greater on the symptomatic side than on the non-symptomatic side. [ABSTRACT FROM AUTHOR]

In order to evaluate photophobia and phonophobia in cluster headache (CH), light and sound-induced discomfort and pain thresholds were measured quantitatively in 50 patients and 50 sex-matched and age-matched headache-free controls. During bout (i.e., during the active period with attacks), CH patients were more sensitive to light and sound than controls (p < 0.001). Outside bout they did not differ significantly from controls except for binaural stimulation. Patients were more photophobic and phonophobic during bout than in the remission period (p < or = 0.05). However, for those tested during bout, the sensitivity to light and sound was not related to the presence of pain during test, usual pain intensity, or pain laterality. In response to a questionnaire about their sensitivity, a significantly higher proportion of patients considered themselves sensitive during bout than outside (91% vs 46% for light [chi 2 = 5.9, p < 0.05] and 89% vs 49% for sound [chi 2 = 4.7, p < 0.05]). These results indicate that photophobia and phonophobia are important accompanying phenomena of cluster bouts. [ABSTRACT FROM AUTHOR]

Quantitative thresholds for discomfort and pain with monocular and binocular light stimuli were measured in 67 controls and 67 migraine patients (37 migraine with aura and 30 migraine without aura). Patients were more photophobic during attack than outside attack (p < 0.03), and they were more sensitive to light than controls even between attacks (p < or = 0.0001). We found no differences in light sensitivity between migraine with aura and migraine without aura (p > or = 0.93). Unilateral pain affected light sensitivity on both sides. When asked with a questionnaire, 74% of patients answered that they were sensitive to light outside attack and 100% were sensitive during attack. Pain thresholds were generally lower among sensitive than non-sensitive patients (p = 0.004), indicating some agreement between subjective opinion and objective measurements of photophobia. Photophobia seems to be an intrinsic property of migraineurs. It is increased by migraine pain, but seems to be unrelated to migraine characteristics such as nausea, severity of attacks, pain character and pain laterality. [ABSTRACT FROM AUTHOR]

This paper reviews both clinical and experimental literature relating to visual dysfunction in migraine, starting with the eye and progressing via the retina and visual pathways to the visual cortex. Migraine is associated with (i) a pupillary sympathetic hypofunction, and (ii) a cortical hypersensitivity to visual stimuli (perhaps only in migraine with aura), the pathogenesis of which remains to be determined. Various hypotheses are discussed, and it is proposed that the methods of visual psychophysics may represent a useful approach in the future study of cortical hyperexcitability in migraine. Paradoxically, little research has been directed towards understanding (i) the photophobia of migraine attacks, and (ii) how migraine may be triggered by visual stimuli. Research aimed at elucidating the mechanisms of these phenomena may enhance understanding of the pathogenes is of migraine. [ABSTRACT FROM AUTHOR]