Nonconvulsive seizures among critically ill children

Seizures are a common manifestation of brain injury from diverse causes. In the intensive care unit (ICU), seizures present a particular diagnostic challenge: among critically ill patients, seizures frequently manifest with only subtle signs, or are entirely nonconvulsive (subclinical), without any clinical manifestations. Clinical assessment may be further clouded by the use of sedative medications or neuromuscular blocking agents. Seizures in this setting may be detectable only by EEG. Identification of nonconvulsive seizures is important because there is reason to believe that they may worsen brain injury, and therefore warrant treatment.^1,–,4

In the current issue of Neurology®, Abend and colleagues⁵ describe a series of critically ill children with altered mental status who underwent continuous EEG (cEEG) monitoring according to locally established clinical practice guidelines. They observed that 46 out of 100 children experienced seizures, of whom 70% had exclusively nonconvulsive seizures and 30% had both convulsive and nonconvulsive seizures. All children who experienced seizures had at least some nonconvulsive seizures. These observations substantiate the findings of several prior retrospective studies of critically ill infants and children that reported nonconvulsive seizure rates of …