Photosensitivity and CHD2 Variants

Sosa, Rebecca García; Nangia, Srishti

doi:10.15844/pedneurbriefs-29-9-1

Cited by 3 publications

(2 citation statements)

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“…As for other Idiopathic Generalized Epilepsies (IGE), recently renamed as Genetic Generalized Epilepsies (GGEs), in EMA a high prevalence of positive family history for epilepsy has been found, leading to the hypothesis of a genetic etiology [1][2][3]. One of the genes strictly related to the syndrome is CHD2, a gene associated with different phenotypes but particularly linked with epilepsy and photosensitivity [4,5].…”

Section: Introductionmentioning

confidence: 99%

“…Photosensitivity, defined as an abnormal cortical response to flickering light, related to electroencephalography changes and associated or not with seizures [5], is considered one of the main triggering factors of seizures in EMA, and the recent genetic discoveries confirm its role as a distinctive and genetically determined feature of the syndrome. Bright light is the most important precipitating factor in EMA.…”

Section: Introductionmentioning

confidence: 99%

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Abnormal visual sensitivity in eyelid myoclonia with absences: Evidence from electrocortical connectivity and non-linear quantitative analysis of EEG signal

Giuliano¹,

Mostile²,

Fatuzzo

et al. 2019

Seizure

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Eyelid myoclonia with absences (EMA) is an epileptic syndrome characterized by eyelid myoclonia with or without absences, eyes closure-induced EEG paroxysms and photosensitivity. Pathophysiological mechanisms of visual sensitivity in EMA are not-fully understood. The objective of the present study was to analyze the electrophysiological dynamics implicated in the visual sensitivity in patients with EMA. Methods: We analyzed data of 10 subjects with diagnosis of EMA and of 10 healthy control subjects. For both patients and controls, 4-seconds artifacts-free electroencephalographic signal epochs recorded were analyzed, during resting state, eyes-opened and eyes-closed tasks. Resting state networks in EEG have been computed using independent components analysis (ICA) LORETA. Moreover, the power law exponent β was obtained for each coordinate as minus the slope of the power spectrum versus frequency in a Log-Log scale. Results: Using LORETA ICA, patients during resting state showed significant differences as compared to controls with a reduction of the physiological alpha activity over the occipital lobe and of the physiological beta activity over the frontal lobe. Immediately after eye closure, a significant increase of beta activity over the frontal lobe was found in the group of patients compared to controls. Power law exponent β analysis showed a significant increase of β over the frontal regions in patients as compared to controls during resting-state and an increase of β over the parieto-occipital regions after eye closure. Conclusion: Abnormal occipital and frontal cortex activities seem to be related with the visual sensitivity and eyelid myoclonia observed in patients with EMA.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Abnormal visual sensitivity in eyelid myoclonia with absences: Evidence from electrocortical connectivity and non-linear quantitative analysis of EEG signal

Giuliano¹,

Mostile²,

Fatuzzo

et al. 2019

Seizure

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Jeavons syndrome featured with visual sensitivity existing as occipital cortex originating focal-to-generalized continuum epilepsy

Niu

Gong

Jiao

et al. 2022

European Journal of Paediatric Neurology

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Semiology, clustering, periodicity and natural history of seizures in an experimental visual cortical epilepsy model

Chang

Leite

Snowball

et al. 2018

Preprint

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Objective:To characterize a rat model of focal neocortical epilepsy for use in developing novel therapeutic strategies in a type of epilepsy that represents a significant unmet need.Methods: Intracortical tetanus toxin (TeNT) injection was used to induce epilepsy in rats.Seizures and their behavioural manifestations were evaluated with continuous videoelectrocorticography telemetry. Results:TeNT injection into rat primary visual cortex induced focal neocortical epilepsy without preceding status epilepticus. The latency to first seizure ranged from 3 to 7 days.Seizure duration was bimodal, with both short (approximately 30s) and long-lasting (>100s) seizures occurring in the same animals. Seizures were accompanied by non-motor features such as behavioural arrest, or motor seizures with or without evolution to generalized tonicclonic seizures. Seizures were commoner during the sleep phase of a light-dark cycle.Seizure occurrence was not random, and tended to cluster with significantly higher probability of recurrence within 24 hours of a previous seizure. Across animals, the number of seizures in the first week could be used to predict the number of seizures in the following 22 days.Significance: The TeNT model of visual cortical epilepsy is a robust model of acquired focal neocortical epilepsy, and is well suited for preclinical evaluation of novel anti-epileptic strategies. We provide here a detailed analysis of the epilepsy phenotype, seizure activity, electrographic features, and the semiology. In addition we provide a predictive framework that can be used to reduce variation and consequently animal use in pre-clinical studies of potential treatments.3 Key Points Tetanus toxin injection into rat visual cortex induces focal cortical epilepsy. Electrographic seizures were associated with non-motor and motor features with or without evolution to generalized tonic-clonic seizures. Seizures could not be provoked by intermittent photic stimulation.  Seizures were clustered in time and exhibited a circadian variation in frequency. The number of seizures in first week after seizure onset could be used to predict the total number of seizures in the following 3 weeks.

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Photosensitivity and CHD2 Variants

Abstract: Investigators from multinational institutions hypothesized that disruption of CHD2, which encodes chromodomain helicase DNA-binding protein 2, would be associated with common forms of photosensitive epilepsy or photosensitivity manifesting as a photoparoxysmal response alone.

Cited by 3 publications

References 3 publications

Abnormal visual sensitivity in eyelid myoclonia with absences: Evidence from electrocortical connectivity and non-linear quantitative analysis of EEG signal

Abnormal visual sensitivity in eyelid myoclonia with absences: Evidence from electrocortical connectivity and non-linear quantitative analysis of EEG signal

Jeavons syndrome featured with visual sensitivity existing as occipital cortex originating focal-to-generalized continuum epilepsy

Semiology, clustering, periodicity and natural history of seizures in an experimental visual cortical epilepsy model

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