title: Electroencephalographic (EEG) Photoparoxysmal Responses Under 5 Years of Age: Diagnostic Implications and Peculiarities.
abstract: Electroencephalographic (EEG) photoparoxysmal response has been little investigated in very young patients. We studied 5055 patients aged less than 5 years with no acquired brain damage, who underwent EEG recording. We determined the prevalence and significance of photoparoxysmal response induced by 1 to 20 Hz photic stimulation. Fifty-three showed photoparoxysmal response and were diagnosed as having Dravet syndrome (11), epileptic encephalopathy with myoclonic seizures (8), neurodegenerative disorders (8), benign idiopathic epilepsies (9), and static disorders with a known or suspected genetic origin (17). Photoparoxysmal response occurred in response to 1 to 5 Hz trains in 41.5% subjects. In most patients with epileptic encephalopathies, photoparoxysmal response was a transient finding: in 53.2%, it failed to be replicated in the recordings performed more than 6 months after initial evaluation. Photoparoxysmal response is rare in patients aged less than 5 years and has some peculiarities such as occurrence with low-frequency stimuli. Its distribution in specific conditions indicates that photoparoxysmal response may be useful in diagnostic workup.
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Binelli
authors.affiliation: Unit of Neuropsychiatry, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ragona
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Canafoglia
authors.affiliation: Unit of Neuropsychiatry, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Freri
authors.affiliation: Unit of Developmental Neurology, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Saletti
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Casazza
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Gilioli
authors.affiliation: Unit of Developmental Neurology, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: D'Arrigo
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Visani
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Panzica
authors.affiliation: Unit of Neuropsychiatry, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Granata
authors.affiliation: Unit of Developmental Neurology, C. Besta Foundation Neurological Institute, Milan, Italy.
authors.forename: Daria
authors.initials: D
authors.lastname: Riva
authors.affiliation: Department of Neurophysiopathology, Epilepsy Centre, C. Besta Foundation Neurological Institute, Milan, Italy franceschetti@istituto-besta.it.
authors.forename: Silvana
authors.initials: S
authors.lastname: Franceschetti
mesh_terms: D001921:Brain / Q000503:physiopathology*; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods*; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D010775:Photic Stimulation / Q000379:methods*
keywords: Dravet syndrome; genetic disorders; intermittent photic stimulation; neurodegenerative disorders; photoparoxysmal response