Abstracts

Rationale:
Polysomnography (PSG) is a common study used in children, both with and without neurological comorbidities, to evaluate for sleep-disordered breathing or nighttime episodes. PSG utilizes limited electroencephalogram (EEG) to stage sleep, but it is not known how reliable this EEG coverage is in identifying epileptiform abnormalities. Moreover, there is limited data on the utility of PSG for determining future risk of seizures in children without a prior diagnosis of epilepsy.
Method:
A retrospective chart review was performed at our urban tertiary care children’s hospital from January 2014 to March 2020. PSG results reporting abnormalities on EEG were identified. Children who underwent subsequent routine EEG (rEEG) were included; exclusion criteria included prior diagnosis of seizures or lack of follow up rEEG. The main outcome measures were results on rEEG and subsequent diagnosis of epilepsy.
Results:
A total of 67 children were identified meeting inclusion criteria. Average age was 6 years and 43 (64%) were male. rEEG was normal in 16 (24%). Epileptiform abnormalities were focal in 37 (55%), generalized in 7 (10%), and mixed in 5 (8%). An additional 2 (3%) had slow background rhythm without epileptiform discharges. Thirty-one patients had neurology clinic follow-up with an average duration of 31 months (range 4-65 months). Of these, 9 (29%) developed seizures or had a recent history of episodes recognized as seizures at first clinic visit. All 3 with generalized epileptiform discharges, 4 out of 19 (21%) with focal epileptiform discharges, and 2 out of 5 (40%) with mixed epileptiform discharges or background slowing were subsequently diagnosed with seizures. None of the 4 patients with a normal rEEG and clinic follow up had seizures. A seizure diagnosis was given at the initial Neurology consultation or within 1 month in the majority of patients (n=6). Of the remaining 3 diagnosed with seizures, one developed seizures within 3-6 months and the other two within 1-2 years. Eight of the 9 patients with an abnormal rEEG were treated with antiepileptic drugs (AEDs).
Conclusion:
Children without a prior history of seizures who are noted to have abnormal EEG findings during PSG are likely to have an abnormal rEEG, though not universally so. Furthermore, although limited by duration of follow-up and small sample size, our study found these children had a high risk of developing seizures requiring AEDs. Children with abnormal EEG on PSG should, at a minimum, undergo a rEEG and follow-up with Neurology as needed for seizures. Future research should focus on quantifying the risk of developing seizures and identifying risk factors, including specific EEG findings and comorbidities.
Funding:
:Not applicable