Sunflower syndrome: a poorly understood photosensitive epilepsy

The epileptic blip syndrome

We report on the case of an adolescent with juvenile myoclonic epilepsy exhibiting compulsory sporadic voluntary movement. These movements entailed the deliberate act of touching her forehead with her hand and were triggered by a short and indefinable cephalic sensation. Upon inquiry regarding the nature of this movement, the patient reported a sudden perception of a peculiar event localized "inside her head". In the course of a prolonged video-electroencephalographic recording, it appeared that the movements consistently followed the occurrence of diffuse Generalized Spike-and-Wave Bursts (GSWBs), lasting one to three seconds. This observation suggests that the impact of the GSWBs on the patient's stream of consciousness could be detected by the patient herself, who attributed it to an internal sensation, like a "blip on a screen". This clinical observation echoes the "blip syndrome", as described by the neurologist James W. Lance thirty years ago. These findings give some support that "blips" could be of an epileptic origin and lend weight to the notion that some patients could perceive their own EEG discharges. Moreover, this observation should be added to the perennial debate on the cognitive impact of intercritical discharges.

Sunflower Syndrome: A Survey of Provider Awareness and Management Preferences

BACKGROUND

Sunflower syndrome is a rare photosensitive pediatric epilepsy characterized by stereotyped hand-waving in response to bright lights. These stereotyped movements with maintained awareness can be mistaken for a movement disorder. This study assessed neurology providers' diagnostic reasoning, evaluation, and treatment of Sunflower syndrome.

METHODS

A 32-question anonymized electronic survey, including a clinical vignette and video of hand-waving in sunlight, was distributed to child neurology providers to assess (1) initial diagnosis and evaluation based on clinical information, (2) updated diagnosis and management after electroencephalography (EEG), and (3) prior experience with Sunflower syndrome.

RESULTS

Among 277 viewed surveys, 211 respondents provided information about initial diagnosis and evaluation, 200 about updated diagnosis, 191 about management, and 189 about prior clinical experience. Most providers (135, 64%) suspected seizure, whereas fewer suspected movement disorders (29, 14%) or were unsure of the diagnosis (37, 22%). EEG was recommended by 180 (85%). After EEG, 189 (95%) diagnosed epilepsy, 111 of whom specifically diagnosed Sunflower syndrome. The majority (149, 78%) recommended antiseizure medications (ASMs) and sun avoidance (181, 95%). Only 103 (55%) had managed Sunflower syndrome. Epileptologists and those with prior clinical experience were more likely to suspect a seizure, order an EEG, and offer ASMs than those without prior experience.

CONCLUSIONS

Although many providers had not managed Sunflower syndrome, the majority recognized this presentation as concerning for epilepsy. Epilepsy training and prior clinical experience are associated with improved recognition and appropriate treatment. Educational initiatives that increase awareness of Sunflower syndrome may improve patient care.

A novel GABRG2 variant in Sunflower syndrome: A case report and video EEG monitoring

OBJECTIVE

Sunflower syndrome is a unique photosensitive epilepsy, characterized by heliotropism and stereotyped seizures associated with handwaving. These handwaving events (HWE) are thought to be an ictal phenomenon, although current data are contrasting. Photosensitive epilepsy occurs in 2%-5% of the epilepsy forms and several pathogenic gene variants have been associated with photosensitive epilepsy. However, the genetic etiology of Sunflower syndrome remains unknown. Antiseizure medications (ASM) efficacious in treating photosensitive epilepsy are valproic acid (VPA) and levetiracetam (LEV) although some forms, such as Sunflower syndrome, can be drug-resistant.

METHODS AND RESULTS

Here, we report an 8-year-old boy with an early onset of episodes of HWE that was initially categorized as behavioral problems for which risperidone was started. However, the medical history was suggestive of Sunflower syndrome, and subsequent video EEG showed focal mostly temporal and frontotemporal (right and left) epileptiform activity and confirmed the epileptic nature of the HWE. Thus, VPA was started and initially led to seizure frequency reduction. Molecular analyses showed a pathogenic variant in GABRG2 (c.1287G>A p.(Trp429Ter)), which has been associated with photosensitive and generalized epilepsy.

SIGNIFICANCE

Overall, clinicians worldwide should be cautious by interpreting HWE and/or other tic-like movements, since an epileptic origin cannot be ruled out. A prompt and correct diagnosis can be made by performing a video EEG early on in the diagnostic process when epileptic seizures are part of the differential diagnosis. Even though the genetic etiology of Sunflower syndrome remains poorly understood, this constellation supports further genetic testing since the detection of a pathogenic variant can help in making correct decisions regarding ASM management.

Neuropsychiatric comorbidities and cognition in epilepsy with eyelid myoclonia: A retrospective pediatric case series

OBJECTIVE

Epilepsy with eyelid myoclonia (EEM) is a rare epileptic syndrome classified within the Genetic Generalized Epilepsies of childhood. It is characterized by a high drug resistance, and little is known about prognostic factors and neurodevelopmental comorbidities. The aim of this study was to describe the clinical features, cognitive profile, and prognostic factors in a series of children with EEM.

METHODS

This is a retrospective observational study of patients diagnosed with EEM from 2012 to 2022 in a tertiary pediatric hospital.

RESULTS

Seventeen patients were analyzed (mean age at symptom onset 5.8 years). Neuropsychiatric comorbidities were present in 76.4% (attention deficit hyperactivity disorder 58.8%, behavioral disorder 11.8%, autism spectrum disorder 11.8%, and psychotic outbreaks 11.8%). Neurocognitive assessment was performed in 75%, revealing cognitive impairment in 66.6% (62.5% with borderline intellectual function and 37.5% with -IQ <70-), with predominant difficulties in executive functions, comprehensive language, and motor skills. Cognitive deterioration was observed in one patient in parallel onset with psychotic symptoms. High refractoriness to antiseizure medication (ASM) was observed, with only 23.5% of the patients being seizure-free after a mean follow-up of 7 years. The most effective ASM was valproic acid, and two of them received ketogenic diet with good response. Regarding prognostic factors, psychotic symptoms were associated with a greater number of antiseizure medication (p < .05) implying a more drug-resistant epilepsy.

SIGNIFICANCE

In our study, we found a high rate of cognitive and psychiatric comorbidities and high refractoriness. These data support the concept of EEM as an intermediate entity between idiopathic generalized epilepsy and epileptic and/or neurodevelopmental encephalopathy. Making a proper diagnosis and management of these comorbidities is necessary to improve prognosis and quality of life in EEM.

Animal Models of Hypertension (ISIAH Rats), Catatonia (GC Rats), and Audiogenic Epilepsy (PM Rats) Developed by Breeding

Research into genetic and physiological mechanisms of widespread disorders such as arterial hypertension as well as neuropsychiatric and other human diseases is urgently needed in academic and practical medicine and in the field of biology. Nevertheless, such studies have many limitations and pose difficulties that can be overcome by using animal models. To date, for the purposes of creating animal models of human pathologies, several approaches have been used: pharmacological/chemical intervention; surgical procedures; genetic technologies for creating transgenic animals, knockouts, or knockdowns; and breeding. Although some of these approaches are good for certain research aims, they have many drawbacks, the greatest being a strong perturbation (in a biological system) that, along with the expected effect, exerts side effects in the study. Therefore, for investigating the pathogenesis of a disease, models obtained using genetic selection for a target trait are of high value as this approach allows for the creation of a model with a "natural" manifestation of the pathology. In this review, three rat models are described: ISIAH rats (arterial hypertension), GC rats (catatonia), and PM rats (audiogenic epilepsy), which are developed by breeding in the Laboratory of Evolutionary Genetics at the Institute of Cytology and Genetics (the Siberian Branch of the Russian Academy of Sciences).

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

Children and adolescents are the largest at-risk group for the appearance of reflex seizures or epilepsy syndromes with a photoparoxysmal response. The aim of this study was to present an overview of the literature regarding photo-dependent reflex seizures. Epilepsy with seizures provoked by intermittent light stimulation is a distinct group of epilepsies; therefore, we focused on reflex seizures provoked by different factors whose common feature is the patient’s response to intermittent photic stimulation. A qualitative search of PubMed/MEDLINE, Scopus, EBSCO, and Cochrane Library electronic databases for selected terms was carried out for scientific articles published up to May 2020 outlining the outcomes of control, observational, and case studies. This scoping review was developed and followed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. The review of the qualitative evidence for the synthesis of photosensitive epilepsy allowed us to distinguish the following categories: light-induced seizures and light-deprived seizures. Differentiating between intermittent photic stimulation-related epilepsy syndromes and seizures is essential in order to determine the length of appropriate treatment. Photo-dependent reflex seizures make up the majority of this type of disorder among reflex seizures. Since there are many seizures provoking factors in the world around us, it is important to distinguish amongst them in order to be able to protect the patient exposed to this factor. It is recommended that the photostimulation procedure be performed during a routine electroencephalogram study.

Visually sensitive seizures: An updated review by the Epilepsy Foundation

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. Virtual reality and 3D images so far appear benign unless they contain specific provocative content, for example, flashes. Images with flashes brighter than 20 candelas/m² at 3-60 (particularly 15-20) Hz occupying at least 10 to 25% of the visual field are a risk, as are red color flashes or oscillating stripes. Equipment to assay for these characteristics is probably underutilized. Prevention of seizures includes avoiding provocative stimuli, covering one eye, wearing dark glasses, sitting at least two meters from screens, reducing contrast, and taking certain antiseizure drugs. Measurement of PPR suppression in a photosensitivity model can screen putative antiseizure drugs. Some countries regulate media to reduce risk. Visually-induced seizures remain significant public health hazards so they warrant ongoing scientific and regulatory efforts and public education.

Case report: A relevant misdiagnosis: Photosensitive epilepsy mimicking a blinking tic

Blinking in children is most frequently a functional and transient symptom. Nonetheless, sometimes it is the first clinical manifestation of a neurological disorder. The differential diagnosis between voluntary actions, tics and other neurological disorders among which seizures may be challenging and misdiagnosis is common. A 6-year-old girl in good health was admitted for a recent history of bilateral eye blinking. Blinking did not interfere with the girl's activities. The patients reported that blinking seemed to be triggered by sunlight exposure and that girl sometimes seemed to be attracted by the sunlight. Ophthalmological diseases had been already excluded. The girl was addressed to our hospital for neurological consultation, as tic disease was considered the most probable hypothesis. Neurological examination was negative. In the field of differential diagnosis of photosensitive abnormal eyelid movements, the hypothesis of seizures was explored and further investigated with a video-EEG recording with light stimulation. This exam demonstrated a photoparoxysmal response (PPR) to intermittent photic stimulation with appearance on EEG of bilateral spike and polyspike waves associated with eyelid jerks. This girl suffers from generalized epilepsy with photosensitivity. Photosensitivity is a common feature of many epilepsy syndromes, mainly occurring in children and adolescents. To control the seizures, it is essential to avoid the triggering stimulus, by wearing specific glasses. Additional antiseizures treatment is often necessary, at first with valproate and levetiracetam, and ethosuximide, lamotrigine, and benzodiazepines as the second choice. Overlapping phenomenology of seizures and movement disorders is well known in paediatric clinical practice. Moreover, epilepsy and movement disorder may coexist, mainly in children. Seizures with semeiology limited to eye motor manifestations may mimic functional blinking, tics, and other motor events frequently observed in childhood. Differentiating seizures from other non-epileptic paroxysmal movements may be challenging and specialist evaluation is needed for proper treatment and prognostic counselling.

Fenfluramine for seizures associated with Sunflower syndrome

AIM

To determine the efficacy of fenfluramine on seizure frequency in patients with Sunflower syndrome. Secondary endpoints were changes in electroencephalogram (EEG) characteristics, cognitive functioning, executive functioning, and quality of life.

METHOD

In this open-label study, patients underwent a 4-week baseline period, followed by 3 months of treatment. An oral solution of fenfluramine was administered twice daily for 3 months. The dose was titrated up to a maximum dose of 0.7mg/kg/day or 26mg/day. Cardiac safety was monitored by transthoracic echocardiogram and electrocardiogram. EEGs, abbreviated neuropsychological testing, and questionnaires were administered before starting the study medication and again at the end of the treatment period.

RESULTS

Ten patients (eight females, two males; mean age 13y 4mo [SD 4y 11mo], range 7-24y) were enrolled in the study. Nine of the 10 patients completed the core study, eight of whom met the primary endpoint. There were no observations of cardiac valvulopathy or pulmonary hypertension during the study.

INTERPRETATION

Treatment with low-dose fenfluramine resulted in a clinically significant reduction in seizure frequency, including hand-waving episodes. Fenfluramine may be an effective treatment option for patients with Sunflower syndrome. What this paper adds Nine patients with Sunflower syndrome were treated with fenfluramine. Eight patients were responders, displaying a ≥30% reduction in seizure activity. Six patients experienced a ≥70% reduction in hand-waving episodes. Improvements on electroencephalogram were observed after treatment with fenfluramine. None of the patients developed evidence of cardiac valvulopathy or pulmonary hypertension.

Transcriptome of the Krushinsky-Molodkina Audiogenic Rat Strain and Identification of Possible Audiogenic Epilepsy-Associated Genes

Audiogenic epilepsy (AE), inherent to several rodent strains is widely studied as a model of generalized convulsive epilepsy. The molecular mechanisms that determine the manifestation of AE are not well understood. In the present work, we compared transcriptomes from the corpora quadrigemina in the midbrain zone, which are crucial for AE development, to identify genes associated with the AE phenotype. Three rat strains without sound exposure were compared: Krushinsky-Molodkina (KM) strain (100% AE-prone); Wistar outbred rat strain (non-AE prone) and “0” strain (partially AE-prone), selected from F2 KM × Wistar hybrids for their lack of AE. The findings showed that the KM strain gene expression profile exhibited a number of characteristics that differed from those of the Wistar and “0” strain profiles. In particular, the KM rats showed increased expression of a number of genes involved in the positive regulation of the MAPK signaling cascade and genes involved in the positive regulation of apoptotic processes. Another characteristic of the KM strain which differed from that of the Wistar and “0” rats was a multi-fold increase in the expression level of the Ttr gene and a significant decrease in the expression of the Msh3 gene. Decreased expression of a number of oxidative phosphorylation-related genes and a few other genes was also identified in the KM strain. Our data confirm the complex multigenic nature of AE inheritance in rodents. A comparison with data obtained from other independently selected AE-prone rodent strains suggests some common causes for the formation of the audiogenic phenotype.

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

Sensory stimuli can induce seizures in patients with epilepsy and predisposed subjects. Visual stimuli are the most common triggers, provoking seizures through an abnormal response to light or pattern. Sensitive patients may intentionally provoke their seizures through visual stimuli. Self-induction methods are widely described in photo-sensitive patients, while there are only a few reports of those who are pattern-sensitive. We analyzed 73 images of environmental visual triggers collected from 14 pattern-sensitive patients with self-induced seizures. The images were categorized according to their topics: 29 Objects (43%); 19 Patterns (28%); 15 External scenes (22%); 4 TV or computer screens (6%). Six photos were of poor quality and were excluded from analysis. Images were analyzed by an algorithm that calculated the degree to which the Fourier amplitude spectrum differed from that in images from nature. The algorithm has been shown to predict discomfort in healthy observers. The algorithm identified thirty-one images (46%) as "uncomfortable". There were significant differences between groups of images (ANOVA p = .0036; Chi2 p < .0279), with higher values of difference from nature in the images classified as "Objects" (mean 6,81E+11; SD 6,72E+11; n.17, 59%) and "Pattern" (mean 9,05E+11; SD 6,86E+11; n.14, 74%). During the semi-structured face-to-face interviews, all patients described the visual triggers as 'uncomfortable'; the appearance of enjoyable visual epileptic symptoms (especially multi-colored hallucinations) transformed uncomfortable images into pleasant stimuli. Patients considered self-induction as the simplest and most effective way to overcome stressful situations, suggesting that self-inducing pattern-sensitive patients often use uncomfortable visual stimuli to trigger their seizures. Among the reasons for the self-inducing behavior, the accidental discovery of pleasurable epileptic symptoms related to these "uncomfortable" visual stimuli should be considered.