BANGKOK – presented by Maggie Lo Yee Yau, MD, at the International Epilepsy Congress.
“Death in these children usually occurred within the first few days after admission to the pediatric ICU,” she said at the congress sponsored by the International League Against Epilepsy.
The study included 15 consecutive patients aged between 1 month and 17 years treated for superrefractory status epilepticus (SRSE) during 2011-2017 at the Chinese University of Hong Kong, where Dr. Yau practices. Seven children died during their index hospital admission, with a median time to death of 8 days. Two more died within several years post discharge.
Morbidity was substantial: At follow-up 1 year after the index episode of SRSE, two patients had a Glasgow Outcome Scale (GOS) score of 3, indicative of severe disability; three patients had moderate disability, with a GOS of 4; and two patients were in a vegetative state, with a GOS of 2, both of whom subsequently died of aspiration pneumonia. Only 1 of the 15 patients had a good recovery. Through 8 years of follow-up, all six survivors had epilepsy. Common nonneurologic deficits included a predisposition to a variety of infections.
By way of background, Dr. Yau noted that convulsive status epilepticus is the most common neurologic emergency in children, with an incidence of about 20 episodes per 100,000. Of affected children, 10%-40% develop refractory status, with reported mortality rates of 16%-43%. SRSE is a term reserved for persistent or recurrent seizures 24 hours or more after onset of general anesthesia for management of refractory status.
The impetus for Dr. Yau’s study was the dearth of data on SRSE in children. The literature consists of a few case series totaling well under 100 patients.
The Hong Kong case series included 15 patients with SRSE who had a median age of 7.9 years, only 1 of whom had preexisting epilepsy, a case of epileptic encephalopathy with severe developmental delay. Of the 15, 12 were boys. The patients were placed on a median of four antiepileptic drugs. Those who survived to discharge spent a median of 17.8 days under general anesthesia and 42.5 days in the pediatric ICU.
The SRSE etiologies included febrile infection–related epilepsy syndrome in two cases, four serious infections, four cases of autoimmune etiology, two cases of epileptic encephalopathy, one patient with hypoxia caused by severe croup, and two of unknown origin despite intensive work-up.
The four in-hospital deaths caused by acute cerebral edema occurred a median 6.5 days after admission. There were also two deaths because of uncontrolled sepsis and one because of intraventricular bleeding secondary to thrombotic thrombocytopenic purpura thought to have occurred as a complication of interactions between the numerous prescribed medications. All six children with an infectious or unknown etiology died in hospital, whereas none of those with an autoimmune etiology, epileptic encephalopathy, or hypoxia did. Duration of anesthesia did not predict mortality.
Other investigators have reported that younger age is associated with higher mortality, but that was not true in the Hong Kong experience. Neither of the two children aged less than 3 years died during their index hospitalization. All 7 deaths occurred in the 13 children age 3 years or older.
When asked whether she thought SRSE or the underlying disorder was the bigger contributor to mortality, Dr. Yau replied that she believes the prolonged refractory seizures may have worsened cerebral edema in some patients and thereby have been the cause of death.
She reported having no financial conflicts regarding her study.