Electrical Status Epilepticus in Sleep (ESES)

What It Is, Causes, Treatment, and More

Author: Emily Miao, PharmD
Editor: Alyssa Haag
Editor: Józia McGowan, DO
Editor: Kelsey LaFayette, DNP
Illustrator: Jessica Reynolds, MS
Modified: Jan 06, 2025

What is electrical status epilepticus in sleep (ESES)?

Electrical status epilepticus in sleep (ESES) is a rare, self-limiting form of non-convulsive status epilepticus (i.e., a seizure of five minutes or more of continuous clinical and/or electrographic seizure discharges) characterized by a specific pattern on electroencephalogram (EEG) during non-rapid eye movement (NREM) sleep. ESES is typically found in children, between 2 and 12 years of age; and can be present with or without clinically apparent seizures. Many children with ESES also have Landau-Kleffner Syndrome (LKS), a rare epilepsy syndrome characterized by the sudden or gradual development of aphasia (e.g., inability to understand or express language) and recurrent epileptic seizures. Recently, the International League Against Epilepsy adopted the term “continuous waves and spikes during sleep” (CSWS) to describe the clinical phenotype (i.e., global development regression) in addition to the EEG pattern of ESES.
Brain waves on an electroencephalogram (EEG).

What causes electrical status epilepticus in sleep (ESES)?

While the pathogenesis of ESES is not fully understood, it is thought to be related to disruptions in the normal electrical activity and neural networks within the brain, especially during the slow-wave sleep phase. Studies have identified various etiologies including structural abnormalities of the brain; concurrent genetic variants; and an imbalance between excitatory (i.e., glutamate) and inhibitory (i.e., GABA) neurotransmitters.  

What are the signs and symptoms of electrical status epilepticus in sleep (ESES)?

Children with ESES mainly present with EEG abnormalities, which can go undetected in those without an apparent preceding seizure event. Individuals with a preceding seizure may experience different types of seizures, including tonic-clonic seizures (i.e., grand mal) which involve rhythmic stiffening and violent jerking of the limbs along with loss of consciousness; and absence seizures (i.e., petit mal), which are characterized by a blank stare into space which lasts for a few seconds. 

Most children meet developmental milestones prior to onset of the condition but experience irreversible neurocognitive impairments and delays following the first seizure. In rare cases, neurocognitive and behavioral regression may appear without any evidence of clinical seizures. During the first few years of the onset, children have higher seizure frequency, which is also associated with a higher risk of global developmental regression. Children with widespread, generalized spike-wave discharges on EEG are more likely to experience severe developmental issues compared to individuals with more focal discharges. 

While ESES can last from months to years and eventually resolve prior to adulthood, the neurocognitive sequelae may be irreversible.

How is electrical status epilepticus in sleep (ESES) diagnosed?

Diagnosing ESES begins with a thorough medical history and physical exam. Early diagnosis of ESES is crucial since there is a significant correlation between irreversible neurocognitive impairments with delayed recognition. A detailed history of the individual’s neurodevelopmental milestones may be elicited, especially following the first seizure, if apparent, and any signs of regression may be noted. 

Diagnosis is confirmed with EEG showing continuous or near-continuous spike-wave discharges during NREM sleep; and intermittent focal and/or multifocal epileptiform discharges during REM sleep. For diagnosis, the spike-wave discharges should also be present in over 50% of the NREM phase. Adequate EEG sampling is essential (i.e., must capture both REM and NREM phases) otherwise the diagnosis may be missed altogether. Brain imaging (e.g., magnetic resonance imaging) can help determine if any structural abnormalities (e.g., neoplasm) are present which may contribute to abnormal EEG findings. 

Finally, because of its association with childhood electroclinical syndromes, LKS and Lennox-Gastaut syndrome should also be considered on the differential. Genetic testing with an epilepsy gene panel for Lennox-Gastaut syndrome pathologic variants (e.g., CDKL5, DNM1) may aid in the diagnosis. Additionally, while the EEGs of individuals with LKS and CSWS both usually show ESES, individuals with LKS typically experience predominant language regression as opposed to global developmental regression seen in CSWS. 

How is electrical status epilepticus in sleep (ESES) treated?

Treatment for ESES is aimed at suppressing EEG abnormalities and improving seizure control in order to prevent long-term neurocognitive sequelae. Current recommendations are based on small retrospective studies and primarily consist of pharmacotherapy with antiseizure agents (e.g., valproic acid and levetiracetam) for the treatment and prevention of seizures. Certain anticonvulsant medications (e.g., phenytoin, phenobarbital, carbamazepine) have been noted to worsen seizure control in ESES, although the mechanisms are not fully understood. High-dose benzodiazepines (e.g.., diazepam) and corticosteroids are also used in treating ESES in order to reduce the percentage of continuous spike-wave discharges. Finally, there are other potentially effective treatments being studied, including a ketogenic diet which consists of consuming a low amount of carbohydrates and a high amount of fat and/or protein; and intravenous immunoglobulin (IVIG), which is an infusion of antibodies taken from the plasma of healthy donors. 

What are the most important facts to know about electrical status epilepticus in sleep (ESES)?

ESES is a rare, self-limiting form of non-convulsive status epilepticus characterized by a specific pattern of continuous epileptic discharges during NREM sleep. While the pathogenesis of ESES is not fully understood, it is thought to be related to disruptions in the normal electrical activity and neural networks within the brain, especially during the slow-wave sleep phase. Various etiologies have been suggested, including structural abnormalities of the brain; concurrent genetic mutations; and an imbalance between counterregulatory neurotransmitters, resulting in disruptions in information processing and memory consolidation. Diagnosis is confirmed with an EEG showing continuous or near-continuous spike-wave discharges during NREM sleep and intermittent focal and/or multifocal epileptiform discharges during REM sleep. Treatment for ESES is aimed at suppressing EEG abnormalities and improving seizure control with antiseizure medications, high-dose benzodiazepines, and corticosteroids, to prevent the long-term neurocognitive sequelae

References


Gencpinar P, Arican P, Olgac Dundar N, Tekgul H. Electrical status epilepticus during slow-wave sleep (ESES): Current perspectives. Journal of Pediatric Neurosciences. 2021;16(2):91. doi:https://doi.org/10.4103/jpn.jpn_137_20


Tassinari CA, Rubboli G. Cognition and paroxysmal EEG activities: From a single spike to electrical status epilepticus during sleep. Epilepsia. 2006;47(s2):40-43. doi:https://doi.org/10.1111/j.1528-1167.2006.00686.x


Scheltens-de Boer M. Guidelines for EEG in encephalopathy related to ESES/CSWS in children. Epilepsia. 2009;50:13-17. doi:https://doi.org/10.1111/j.1528-1167.2009.02211.x


Sánchez Fernández I, Loddenkemper T, Peters JM, Kothare SV. Electrical status epilepticus in sleep: Clinical presentation and pathophysiology. Pediatr Neurol. 2012 Dec;47(6):390-410. doi: 10.1016/j.pediatrneurol.2012.06.016.