Ictal-Interictal Continuum in the Pediatric Intensive Care Unit

Area of Science:

• Neuroscience
• Pediatric Critical Care
• Clinical Electrophysiology

Background:

• The ictal-interictal continuum (IIC) comprises electroencephalogram (EEG) patterns frequently observed in critically ill adults.
• Research on IIC in critically ill children is limited, with prior studies focusing on associations with electrographic seizures (ESs).
• This study investigates the incidence and associations of IIC in the pediatric intensive care unit (PICU).

Purpose of the Study:

• To determine the incidence of IIC in the PICU.
• To compare IIC patterns with rhythmic and periodic patterns (RPPs) not meeting IIC criteria.
• To identify associations between IIC/RPPs and acute cerebral abnormalities, ESs, and in-hospital mortality.

Main Methods:

• Retrospective review of prospectively collected continuous EEG data from PICU patients (July 2021-January 2023).
• Exclusion of patients with pre-existing epilepsy or cerebral injury.
• Application of American Clinical Neurophysiology Society standardized Critical Care EEG terminology for IIC and RPP classification.

Main Results:

• Of 201 patients, 12% (24/201) met IIC criteria, and 21% (42/201) had RPPs.
• IIC patterns were associated with a high incidence of ESs (83%) and cerebral injury (96%).
• Both IIC and RPPs correlated with acute cerebral abnormalities, but only IIC was significantly associated with ESs.

Conclusions:

• Rhythmic and periodic patterns, including IIC, are prevalent in the PICU and linked to cerebral injury.
• The IIC occurs in over 10% of critically ill children and is associated with ESs.
• Further research is needed to understand the independent impact of RPPs and IIC on secondary brain injury and treatment necessity.