Summary:  Purpose: Questioning the presence of any possible prognostic predictors, this study includes a long‐term follow‐up of clinical and EEG characteristics of 16 patients with idiopathic partial epilepsy (IPE) who subsequently developed epilepsy with electrical status epilepticus during slow sleep (ESES) spectrum disorders. Methods: Epilepsy, cognitive and behavioral parameters, and waking and non–rapid eye movement (NREM) EEG data were evaluated and scored for initial stage (i.e., IPE stage), preESES, ESES, and ESES remission periods, individually, on a chronologic basis. Data from 25 healthy subjects who had had IPE at the appropriate ages served for comparison with the patients' data during the IPE stage. Results: Results revealed a higher incidence in seizure frequency and variability in the ESES group and a resistance to a single antiepileptic drug (AED), as compared with controls, during the IPE stage. Mean age at onset of epilepsy was younger in the ESES group versus controls (5.5 and 7.3 years, respectively). At least one of the premonitory clinical features for development of ESES [an increase in the seizure frequency and/or addition of new types of seizures (93%), appearance of cognitive and/or behavioural changes (81.2%), or a progression in EEG abnormalities (66%)] was present in all patients. Epilepsy remitted in patients within the ESES spectrum at a similar age as in controls in 81.2%, as ESES findings in the EEG disappeared by age 13 years in 94%. Seizure prognosis proved to be the most favorable among the questioned parameters. Conclusions: An increase in seizure frequency or development of new seizure types, a deviance in behavior or decrease in cognitive performance, or a spreading tendency of the previously focal abnormalities in control EEGs may be premonitory features of a developing ESES and necessitate close follow‐ups with sleep EEGs in children with IPEs.

Objective: This study aimed to investigate the relationship between autism spectrum disorder (ASD) and vitamin D levels in children and adolescents. Methods: We measured serum 25-hydroxyvitamin D (25-OHD) levels in 1529 patients with ASD aged 3 to 18 years, without any additional chronic diseases. Levels of 25-OHD were compared according to sex, age (<11 or ≥11 years), and birth season. Additionally, laboratory parameters (calcium, phosphorus, alkaline phosphatase, and 25-OHD) of 100 selected patients with ASD were compared with those of the healthy control group. Results: Vitamin D deficiency or insufficiency was found in approximately 95% of all patients. Levels of 25-OHD in adolescent patients with ASD aged 11 to 18 years were significantly lower than those in patients aged younger than 11 years. In the 100 selected patients with ASD, mean serum 25-OHD levels were significantly lower and alkaline phosphatase levels were higher compared with those in healthy children. Conclusion: Our study suggests a relationship between vitamin D and ASD in children. Monitoring vitamin D levels is crucial in autistic children, especially adolescents, to take protective measures and treat this condition early.