Characteristics of visual evoked potentials related to the electro-clinical expression of reflex seizures in photosensitive patients with idiopathic occipital lobe epilepsy

Brinciotti, M.; Mittica, A.; Matricardi, M.

doi:10.1016/j.eplepsyres.2020.106345

Cited by 9 publications

(7 citation statements)

References 41 publications

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“…Several observations indicate that the occipital cortex or visual system in patients with photosensitive epilepsy is hyperexcitable. Visual evoked potentials (VEPs) have a higher amplitude in photosensitive patients with generalized or occipital lobe epilepsies when compared to healthy controls or patients without photosensitive epilepsy 198,201–203 . The increase in VEP amplitude depends on factors such as the contrast of the stimuli used and eye closure.…”

Section: Mechanisms Of Photosensitivitymentioning

confidence: 99%

“…Visual evoked potentials (VEPs) have a higher amplitude in photosensitive patients with generalized or occipital lobe epilepsies when compared to healthy controls or patients without photosensitive epilepsy. 198,[201][202][203] The increase in VEP amplitude depends on factors such as the contrast of the stimuli used and eye closure. In addition, VEPs in patients with photosensitive epilepsy respond differently to repetitive transcranial magnetic stimulation (rTMS) than VEPs in controls.…”

Section: Sensitivitymentioning

confidence: 99%

“…Inciting stimuli in photosensitive individuals can be light flashes, color changes, or certain moving patterns. 203 In 2005, a panel convened by the Epilepsy Foundation of America 259,260 concluded that a flash is a potential hazard if it is brighter than 20 candelas per square meter, occupies at least 10% of the visual field, flashes or changes color at a frequency between 3 and 60 Hz, and endures for at least half a second. Similar parameters apply to color changes, which are particularly problematic when to and from saturated red 195 with a large chromaticity difference.…”

Section: Stimulus Characteristicsmentioning

confidence: 99%

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Visually sensitive seizures: An updated review by the Epilepsy Foundation

et al. 2022

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Light flashes, patterns, or color changes can provoke seizures in up to 1 in 4000 persons. Prevalence may be higher because of selection bias. The Epilepsy Foundation reviewed light-induced seizures in 2005. Since then, images on social media, virtual reality, three-dimensional (3D) movies, and the Internet have proliferated. Hundreds of studies have explored the mechanisms and presentations of photosensitive seizures, justifying an updated review. This literature summary derives from a nonsystematic literature review via PubMed using the terms "photosensitive" and "epilepsy." The photoparoxysmal response (PPR) is an electroencephalography (EEG) phenomenon, and photosensitive seizures (PS) are seizures provoked by visual stimulation. Photosensitivity is more common in the young and in specific forms of generalized epilepsy. PS can coexist with spontaneous seizures. PS are hereditable and linked to recently identified genes. Brain imaging usually is normal, but special studies imaging white matter tracts demonstrate abnormal connectivity. Occipital cortex and connected regions are hyperexcitable in subjects with light-provoked seizures. Mechanisms remain unclear. Video games, social media clips, occasional movies, and natural stimuli can provoke PS.

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Section: Mechanisms Of Photosensitivitymentioning

confidence: 99%

Section: Sensitivitymentioning

confidence: 99%

Section: Stimulus Characteristicsmentioning

confidence: 99%

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Visually sensitive seizures: An updated review by the Epilepsy Foundation

et al. 2022

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“…Low-frequency visual evoked potentials (VEP) is mostly limited for testing the functional integrity of the visual system (47), and is less explored in epilepsy. Studies in patients with photosensitive occipital lobe epilepsy reported increased VEP amplitudes consistent with hypersynchrony (48, 49), and abnormal latencies possibly due to failure of cortical gain control (48). VEP may be a valuable tool to investigate brain excitability, especially sub-seizure-threshold network dynamics.…”

Section: Discussionmentioning

confidence: 99%

Elevated photic response is followed by a rapid decay and depressed state in ictogenic networks

Myren‐Svelstad

Jamali

Ophus

et al. 2022

Preprint

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The switch between non-seizure and seizure states involves profound alterations in network excitability and synchrony. Both increased and decreased excitability may underlie the state transitions, as shown in epilepsy patients and animal models. Inspired by video-electroencephalography recordings in patients, we developed a framework to study spontaneous and photic-evoked neural and locomotor activity in zebrafish larvae. We combined high-throughput behavioral tracking and whole-brain in vivo two-photon calcium imaging to perform side-by-side comparison of multiple zebrafish seizure and epilepsy models. Our setup allowed us to dissect behavioral and physiological features that are divergent or convergent across multiple seizure models. We observed that locomotor and neural activity during interictal and spontaneous ictal periods exhibit great diversity across seizure models. Yet, during photic stimulation, hyperexcitability and rapid response dynamics was well conserved across multiple seizure models, highlighting the reliability of photic-evoked seizure activity for high-throughput assays. Intriguingly, in several seizure models, we observed that the initial elevated photic response is often followed by fast decay of neural activity and a prominent depressed state. We argue that such depressed states are likely due to homeostatic mechanisms triggered by excessive neural activity. An improved understanding of the interplay between elevated and depressed excitability states might suggest tailored epilepsy therapies.

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“…Each frequency was tested by separate trains of flashes with an inter-stimulus free period of five seconds, with eyes opened, eyes closed, and during eye closure. Pattern sensitivity was tested using a standard procedure of stimulation, according to recommended guidelines [17] , as reported elsewhere [18]. Briefly, we used three types of black-and-white full-field pattern (checks, horizontal stripes, vertical stripes), two black-andwhite hemi-field patterns (left and right, horizontal stripes), and one red/blue full-field pattern (horizontal stripes).…”

Section: Commission On Classification and Terminology Commission Of T...mentioning

confidence: 99%

Pattern-sensitive patients with epilepsy use uncomfortable visual stimuli to self-induce seizures

Brinciotti

Wilkins

Penacchio

et al. 2021

Epilepsy & Behavior

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Characteristics of visual evoked potentials related to the electro-clinical expression of reflex seizures in photosensitive patients with idiopathic occipital lobe epilepsy

Abstract: Characteristics of visual evoked potentials related to the electro-clinical expression of reflex seizures in photosensitive patients with idiopathic occipital lobe epilepsy,

Cited by 9 publications

References 41 publications

Visually sensitive seizures: An updated review by the Epilepsy Foundation

Visually sensitive seizures: An updated review by the Epilepsy Foundation

Elevated photic response is followed by a rapid decay and depressed state in ictogenic networks

Pattern-sensitive patients with epilepsy use uncomfortable visual stimuli to self-induce seizures

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