Electrical status epilepticus during sleep: A study of 67 patients

Objectives: We aimed to study clinical features, etiology, neuroimaging findings, treatment, and outcome in patients with electrical status epilepticus during sleep (ESES). Methods: The study included 67 patients diagnosed with ESES pattern on EEG (40 males, 27 females) between 2015-2020 at our center. We retrospectively reviewed data on clinical, EEG and neuroimaging findings and neuropsychometric tests. Results: The median age at the initial admission was 60 months (0.03-124). Main symptom at admission was seizure 86.5% (n=58). The median age at the onset of ESES, and follow-up duration was 97 months (22-193), and 28 months (4-69) respectively. At the time of ESES diagnosis, 48 patients had ongoing seizures; 13 had focal onset, 35 had generalized seizures. Of 67 patients, 25 were on monotherapy, 40 were on polytherapy, 2 patients were not on anti seizure medication (ASM). After ESES diagnosis, ASM treatments were adjusted. Most common ASMs were valproate and benzodiazepines. Median duration of recovery from ESES was 24.5 months (range 4–69 months) in 42/67 (62%) of the patients. The leading etiology was structural causes (n= 18 acquired, n= 4 congenital) detected in 22 patients (32.8%). At final visit; 5 patients showed improved cognition, 28 patients had cognitive decline, and 34 patients remained similar compared to baseline evaluation. Conclusion: ESES has a complex etiological profile, and cognitive impairment is seen in majority of patients. The treatment choices are based on the centers' experience, mostly retrospective studies, and case studies. To reduce the risk of cognitive impairment, standard treatment algorithms are required.
Keywords: Electrical status epilepticus in sleep (ESES), Seizure, Neurocognitive outcome