Sourbron Jo, Proost Renee, Jansen Katrien, Riva Antonella, Eschermann Kirsten, Barnett James Richard, Lagae Lieven
Section Pediatric Neurology, Department of Development and Regeneration, University Hospital KU Leuven, Leuven, Belgium.
Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.
Epileptic Disord. 2023 Dec;25(6):815-822. doi: 10.1002/epd2.20154. Epub 2023 Sep 15.
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.
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.
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.
向日葵综合征是一种独特的光敏性癫痫，其特征为向阳性和与挥手动作相关的刻板发作。尽管目前的数据存在矛盾，但这些挥手动作（HWE）被认为是一种发作期现象。光敏性癫痫在2%-5%的癫痫类型中出现，并且几种致病基因变异与光敏性癫痫有关。然而，向日葵综合征的遗传病因仍然未知。治疗光敏性癫痫有效的抗癫痫药物（ASM）是丙戊酸（VPA）和左乙拉西坦（LEV），尽管某些类型，如向日葵综合征，可能对药物耐药。
在此，我们报告一名8岁男孩，其早期出现HWE发作，最初被归类为行为问题并开始使用利培酮治疗。然而，病史提示为向日葵综合征，随后的视频脑电图显示主要为局灶性颞叶和额颞叶（右侧和左侧）癫痫样活动，并证实了HWE的癫痫性质。因此，开始使用VPA，最初导致发作频率降低。分子分析显示GABRG2基因存在致病变异（c.1287G>A p.(Trp429Ter)），该变异与光敏性和全身性癫痫有关。
总体而言，全球临床医生在解释HWE和/或其他抽动样动作时应谨慎，因为不能排除癫痫起源。当癫痫发作是鉴别诊断的一部分时，在诊断过程早期进行视频脑电图检查可做出快速、正确的诊断。尽管向日葵综合征的遗传病因仍了解甚少，但这一情况支持进一步的基因检测，因为检测到致病变异有助于就ASM治疗做出正确决策。
