The electroclinical features of idiopathic generalized epilepsy patients presenting with fixation‐off sensitivity

Abstract

Aims. To determine the electroclinical features of fixation‐off sensitivity (FOS) in patients with idiopathic generalized epilepsy (IGE). Methods. We searched the EEG database using the terms “fixation‐off sensitivity” and “idiopathic generalized epilepsy” over a four‐year period from March 2014 to April 2018 in the Xijing Hospital, Xi’an, China. FOS was evaluated according to the technique proposed by Panayiotopoulos. Photic stimulation procedure and neuropsychological testing were performed during video‐EEG monitoring. Results. FOS was observed in eight patients with several different IGE syndromes, including four with eyelid myoclonia/Jeavons syndrome, two with juvenile myoclonic epilepsy, one with photosensitivity epilepsy, and one with epilepsy with generalized tonic‐clonic seizures only. FOS was associated with seizures in five patients manifesting with eyelid myoclonic, myoclonic, and myoclonic‐tonic‐clonic seizures, and eyelid myoclonic status. FOS coexisted with photosensitivity in six patients as independent EEG features. Neuropsychological testing revealed transitory cognitive impairments associated with FOS. Conclusions. FOS is associated with several different IGE syndromes and may coexist with photosensitivity in the same patient as independent EEG features. FOS may be associated with both clinical seizures and cognitive impairments. Intermittent photic stimulation and registration of different eye conditions with and without fixation will aid the study of the dynamics of the visual system in epilepsy patients. [Published with video sequences on http://www.epilepticdisorders.com]

Epilepsy with eyelid myoclonias (Jeavons syndrome): An electro-clinical study of 40 patients from childhood to adulthood

“…We also showed a possible circadian influence on the discharges, with a potential activating effect of the sleep-wake transition [26,34,35] as in other absence epilepsies [36]. It is not always easy to distinguish ECS from FOS, considering that the two phenomena can coexist and may be misinterpreted [13,37]. Eye-closure-related paroxysms are self-limited, of brief duration, and are suppressed by complete darkness.…”

“…This phenomenon, known as eye closure sensitivity (ECS), is one of the hallmarks of JS, and it should be distinguished from fixation-off sensitivity (FOS), which consists of EEG abnormalities that are elicited by the elimination of central vision and fixation [12]. In JS patients, FOS phenomenon is reported [13], although it does not seem to represent the primary trigger of EM and/or EEG discharges, as recently reported [14]. Photosensitivity is almost invariably present, although its clinical and EEG expression tends to decrease with age and can be modified by antiseizure drugs (ASDs) [3,10].…”

Photo-Dependent Reflex Seizures—A Scoping Review with Proposal of Classification

“…Seven articles present seizures provoked by lack of light or lack of fixation of eyesight. There are two types of stimulation-fixation-off and scotosensitivity [39][40][41][42][43][44][45].…”

“…Studies presented results for sample with a broad age range including adults without separate data presentation for only pediatric participants were included. Overall, 17 reports were included in the review [5,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] with three of the included articles being case reports. Based on the guidelines, 17 publications linked to the research topic met the criteria for inclusion in the scoping review (Figure 1).…”

EEG Markers of Treatment Resistance in Idiopathic Generalized Epilepsy: From Standard EEG Findings to Advanced Signal Analysis

“…Eye-closure sensitivity must be distinguished by fixation-off sensitivity, which is an exceptional finding in IGE and is defined as the occurrence of occipital or generalized EDs induced by elimination of central vision and fixation (e.g., by keeping the eye closed during routine EEG, wearing Frenzel or spherical lenses, etc.) [ 13 ]. In addition to intermittent photic stimulation-sensitivity, photosensitive IGE patients may also be reactive to visual patterns, typically stripes.…”