Electroencephalographic abnormalities in children with type 1 diabetes mellitus: a prospective study

The aim herein was to investigate epileptiform discharges on electroencephalogram (EEG), their correlation with glutamic acid decarboxylase 65 autoantibody (GAD-ab) in newly diagnosed pediatric type 1 diabetes mellitus (T1DM) patients and interpret their medium-term utility in predicting epilepsy.

Children presenting with T1DM between July 2018 and December 2019 were included in this prospective longitudinal study. Patients with a history of head injury, chronic illness, neurological disorder, seizure, autism, or encephalopathy were excluded. EEGs were obtained within the first 7 days of diagnosis and later reviewed by a pediatric neurologist. All of the children were clinically followed-up in pediatric endocrinology and neurology clinics for 2 years after their diagnosis.

A total of 105 children (46 male, 43.8%) were included. The mean age at the time of diagnosis was 9.6 ± 4.1 years (range: 11 months-17.5 years). At the time of admission, 24 (22.9%), 29 (27.6%), and 52 (49.5%) patients had hyperglycemia, ketosis, and diabetic ketoacidosis, respectively. GAD-ab was positive in 55 children (52.4%). No background or sleep architecture abnormalities or focal slowing were present on the EEGs. Of the patients, 3 (2.9%) had focal epileptiform discharges. The mean GAD-ab levels of the remaining 102 patients were 7.48 ± 11.97 U/mL (range: 0.01-50.54) (p = 0.2). All 3 children with EEG abnormality had higher levels of GAD-ab (3.59 U/mL, 31.3 U/mL, and 7.09 U/mL, respectively). None of the patients developed epilepsy during the follow-up, although 1 patient experienced Guillain-Barré syndrome (GBS).

The prevalence of epileptiform discharges in the patients was similar to those of previous studies, in which healthy children were also included. No relationship was found between the epileptiform discharges and GAD-ab, and none of the patients manifested seizures during the first 2 years of follow-up of T1DM. These data support the findings of previous studies reporting that T1DM patients with confirmed electroencephalographic abnormalities do not have an increased risk of epilepsy. On the other hand, GBS might be considered as another autoimmune disease that may be associated with T1DM in children.