Continuous Spikes and Waves during Sleep: Electroclinical Presentation and Suggestions for Management

Abstract

Continuous spikes and waves during sleep (CSWS) is an epileptic encephalopathy characterized in most patients by (1) difficult to control seizures, (2) interictal epileptiform activity that becomes prominent during sleep leading to an electroencephalogram (EEG) pattern of electrical status epilepticus in sleep (ESES), and (3) neurocognitive regression. In this paper, we will summarize current epidemiological, clinical, and EEG knowledge on CSWS and will provide suggestions for treatment. CSWS typically presents with seizures around 2–4 years of age. Neurocognitive regression occurs around 5-6 years of age, and it is accompanied by subacute worsening of EEG abnormalities and seizures. At approximately 6–9 years of age, there is a gradual resolution of seizures and EEG abnormalities, but the neurocognitive deficits persist in most patients. The cause of CSWS is unknown, but early developmental lesions play a major role in approximately half of the patients, and genetic associations have recently been described. High-dose benzodiazepines and corticosteroids have been successfully used to treat clinical and electroencephalographic features. Corticosteroids are often reserved for refractory disease because of adverse events. Valproate, ethosuximide, levetiracetam, sulthiame, and lamotrigine have been also used with some success. Epilepsy surgery may be considered in a few selected patients.

Seizures and Brain Regulatory Systems

“…Childhood epilepsy syndromes are frequently associated with increased epileptogenicity during NREM sleep, as seen in continuous spike-waves during sleep (Sanchez Fernandez et al, 2013). Absence seizures preferentially occur during the first phases of NREM sleep (Matos et al, 2010).…”

Electroencephalographic patterns during sleep in children with chromosome 15q11.2-13.1 duplications (Dup15q)

“…It is an age-related condition in children and adolescents occurring in 0.5% of patients with epilepsy [12]. The most common presentation of CSWS is a sleeprelated seizure in a child with normal neurocognitive function prior to CSWS onset [12]. Cognitive regression typically occurs within 2-3 years (age of onset: 4-7.7 years) [12].…”

“…The most common presentation of CSWS is a sleeprelated seizure in a child with normal neurocognitive function prior to CSWS onset [12]. Cognitive regression typically occurs within 2-3 years (age of onset: 4-7.7 years) [12]. The pathophysiology of CSWS is poorly understood.…”

“…Impaired feed-forward inhibition of thalamocortical neurons may create a pathological reinforcing loop in an oscillatory corticothalamocortical network [13]. The ILAE criteria do not specify a minimum percentage value of ESES when diagnosing CSWS; a range of 50-85% of spike and wave activity occupying non-REM sleep is commonly used [12].…”

Acetazolamide for electrical status epilepticus in slow‐wave sleep

“…The treatment of LKS and CSWS can be challenging, often including numerous antiepileptic drugs, immunomodulatory agents, and even surgical interventions . Relapse is common.…”