The Investigation of Epileptic Encephalopathy Etiologies and Electroclinical Manifestations in Children of Northwest of Iran

Abstract

Tabriz Children's Hospital is currently equipped with vEEG monitoring facilities, therefore, considering that no study has been done in this regard in Iran, as the only center equipped with vEEG in the northwest of the country, we decided to examine the causes, prevalence, and importance of clinical and electroencephalographic manifestations of epileptic encephalopathy patients. Materials and Methods: All patients who have been referred to the neurology clinic of the children's hospital due to treatment-resistant epilepsy were selected by the inclusion and exclusion criteria and underwent vEEG, and then the patients with epileptic encephalopathy confirmation was selected and the study information was collected in the patients and recorded in the questionnaire. If necessary, additional examinations such as imaging and metabolic tests were used to confirm the etiological diagnosis. Results: 111 patients with a median age of 55 months (2-193 months) and male predominance (55.9%) were examined. The most common type of EE with a frequency of 73.9% was related to Generalized and also in 5.4% of cases, the type of EE was unknown. The average age of onset of seizures in patients was 9 months, and in 11.7% of patients, the age of onset of seizures was under 1 month. Significantly, the median age of seizure onset was the lowest in Combined EE and the highest in Unknown EE (5.5 months vs. 16 months; p=0.001). The etiology of EE was known in 34.2% of cases, and the most common etiology was structural (18%) followed by genetic (9%). The most common clinical diagnoses in patients are related to Epileptic Encephalopathy (46.8%), followed by LGS (19.8%) and CSWS (16.2%), and significantly the frequency of EE (47.6%) and LGS (20.7%) diagnoses were higher in Generalized EE (p=0.001). In terms of EEG Background, 85.6% of patients had Slow Background, which was significantly higher in EE (52.6%) and LGS (21.1%) diagnoses (p=0.002). Also, Sleep Features were positive in 18 patients, of which 6 cases were related to the diagnosis of CSWS and 5 cases were related to the diagnosis of EMAS. On the other hand, out of 93 negative cases, the highest frequency was related to the diagnoses of EE (51.6%) and then LGS (22.6%). The most common discharges of awakening and sleeping patients were generalized (87.4%) and then focal (10.8%). Discharge was not detected in 2 patients during sleep and wakefulness.