0000000000498168
AUTHOR
Nadia Bolognini
Visual cortex hyperexcitability in migraine in response to sound-induced flash illusions
Objective: Sound-induced flash illusions depend on visual cortical excitability. In this study, we explored whether sound-induced flash illusions are perceived differently in migraine, a condition associated with pathologic cortical hyperexcitability. Methods: Sound-induced flash illusions were examined in 59 migraine patients (mean age = 32 ± 16 years; 36 females), 32 without aura and 27 with aura, and in 24 healthy controls (mean age = 42 ± 17 years; 16 females). Patients were studied during attacks and interictally. Visual stimuli (flashes) accompanied by sounds (beeps) were presented in different combinations: a single flash with multiple beeps was given to induce the perception of mult…
Cathodal occipital tDCS is unable to modulate the sound induced flash illusion in migraine
Migraine is a highly disabling disease characterized by recurrent pain. Despite an intensive effort, mechanisms of migraine pathophysiology still represent an unsolved issue. Evidence from both animal and human studies suggests that migraine is characterized by hyperresponsivity or hyperexcitability of sensory cortices, especially the visual cortex. This phenomenon, in turn, may affect multisensory processing. Indeed, migraineurs present with an abnormal, reduced, perception of the Sound-induced Flash Illusion (SiFI), a crossmodal illusion that relies on optimal integration of visual and auditory stimuli by the occipital visual cortex. Decreasing visual cortical excitability with transcrani…
O069. Menstrual cycle affects cortical excitability differently in females with migraine and in healthy controls: a new perspective by cross modal sound induced flash illusions
The sound-induced flash illusions (SIFI) represent a valid tool to explore multimodal perception and are critically dependent on visual and acoustic cortical excitability [1, 2]. In a previous study [3], we observed a significant reduction of illusions in migraine patients with respect to healthy controls, probably due to a condition of visual cortex hyperexcitability. Aim of the present study was to evaluate SIFI perceptions in healthy women and patients with menstrual migraine and to describe the effects of cyclical change of steroid hormones and cortical responsiveness.
OnabotulinumtoxinA Modulates Visual Cortical Excitability in Chronic Migraine: Effects of 12-Week Treatment
Chronic migraine is a burdensome disease presenting with episodic pain and several symptoms that may persist even among headache attacks. Multisensory integration is modified in migraine, as assessed by the level of the perception of sound-induced flash illusions, a simple paradigm reflecting changes in cortical excitability which reveals to be altered in migraineurs. OnabotulinumtoxinA is an effective preventive therapy for chronic migraineurs, reducing peripheral and central sensitization, and may influence cortical excitability. Patients affected by chronic migraine who started onabotulinumtoxinA preventive therapy were included. Clinical effects (headache diaries and migraine related qu…
O046. Color vision and visual cortex excitability are impaired in episodic migraine. Simply coexisting or pathophysiologically related dysfunctions?
Background and objectives Evidence of abnormal color vision processing in migraine comes from observation of positive symptoms during visual aura, effects of strong color contrast triggering attacks and of colored-spectacles reducing migraine frequency. Although the central or peripheral basis of such color misperception remains unclear, several authors reported a selective deficit of shortwavelength cones (S-cones) [1]. Sound-induced flash illusions (SIFI) are a simple way to describe visual distorsion induced by acoustic perception. SIFI critically depend on excitability of primary visual cortex (V1) as they are reduced by facilitatory anodal transcranial direct current stimulation (tDCS)…
The effects of estradiol levels on crossmodal perception: a study on the sound induced flash illusion in healthy and menstrually related migraine individuals
Abstract Objective The sound-induced flash illusion (SIFI) is a valid paradigm to study multisensorial perception. In the “fission” SIFI, multiple flashes are perceived when observing a single flash paired with two or more beeps. SIFI is largely dependent on visual and acoustic cortex excitability; in migraine, dysfunctional cortical excitability affects SIFI perception. Since estrogen peak occurring during ovulation can increase neuronal excitability, the present study aims to verify whether cortical excitability shifts linked to the menstrual cycle could influence SIFI. Methods In a comparative prospective study, we tested the effect of estrogens on crossmodal perception using the SIFI. W…
Multisensorial Perception in Chronic Migraine and the Role of Medication Overuse.
Multisensory processing can be assessed by measuring susceptibility to crossmodal illusions such as the Sound-Induced Flash Illusion (SIFI). When a single flash is accompanied by 2 or more beeps, it is perceived as multiple flashes (fission illusion); conversely, a fusion illusion is experienced when more flashes are matched with a single beep, leading to the perception of a single flash. Such illusory perceptions are associated to crossmodal changes in visual cortical excitability. Indeed, increasing occipital cortical excitability, by means of transcranial electrical currents, disrupts the SIFI (ie, fission illusion). Similarly, a reduced fission illusion was shown in patients with episod…
Multisensory integration in hemianopia and unilateral spatial neglect: Evidence from the sound induced flash illusion.
Recent neuropsychological evidence suggests that acquired brain lesions can, in some instances, abolish the ability to integrate inputs from different sensory modalities, disrupting multisensory perception. We explored the ability to perceive multisensory events, in particular the integrity of audio-visual processing in the temporal domain, in brain-damaged patients with visual field defects (VFD), or with unilateral spatial neglect (USN), by assessing their sensitivity to the 'Sound-Induced Flash Illusion' (SIFI). The study yielded two key findings. Firstly, the 'fission' illusion (namely, seeing multiple flashes when a single flash is paired with multiple sounds) is reduced in both left- …
Sound-Induced Flash Illusions Support Cortex Hyperexcitability in Fibromyalgia
Objectives. Fibromyalgia (FM) is characterized by spontaneous chronic widespread pain in combination with hyperalgesia to pressure stimuli. Sound-induced flash illusions (SIFIs) reflect cross-modal interactions between senses allowing to assess a visual cortical hoerexcitability (VCH) by evaluating the fission and fusion illusions disruption. The aims of the present study were to explore whether SIFIs are perceived differently in patients with fibromyalgia as compared to healthy controls (HCs) and how migraine affects fission and fusion illusions in fibromyalgia. Methods. A single flash (F) accompanied by 0 to 4 beeps (B) was presented to induce the fission illusion while multiple flash (i.…