HONOLULU – In the first 2 years following pediatric intracerebral hemorrhage, one-third of patients will experience a single remote symptomatic seizure and 13% will develop epilepsy, according to a large prospective study.
Twenty-eight percent of study participants who underwent continuous EEG monitoring were found to have subclinical EEG-only seizures. Additional follow-up will determine whether these subclinical seizures constitute a risk factor for later epilepsy, Dr. Lauren A. Beslow said at the International Stroke Conference sponsored by the American Heart Association.
She presented a three-center prospective cohort study involving 20 neonates and 53 other patients up to 18 years of age who experienced an intracerebral hemorrhage (ICH).
While 73 subjects may not sound like a lot, this is in fact an exceptionally large cohort, as pediatric ICH is an understudied topic. The incidence of stroke in U.S. children is 6.4 cases per 100,000 per year, a rate approaching that of pediatric brain tumors. And while intracerebral hemorrhage accounts for only about 15% of adult strokes, it is the cause of half of all strokes in children, according to Dr. Beslow, a pediatric neurologist at Yale University, New Haven, Conn.
Acute symptomatic seizures – that is, seizures occurring at presentation of ICH or up to 7 days afterward – were documented in 12 of 20 neonates (60%) and 23 of 53 older subjects (43%). The median age of non-neonates with acute symptomatic seizures was 2.2 years, compared with 10.8 years for subjects without such seizures.
Nine of 32 (28%) subjects placed on continuous EEG monitoring experienced EEG-only seizures. These subclinical seizures were treated medically in the same way that’s standard for symptomatic seizures.
Seizures occurring more than 7 days post ICH are deemed "remote." Eighteen percent of study participants experienced a remote symptomatic seizure during the first year of follow-up. At 2 years, 24 subjects (33%) had a remote symptomatic seizure.
Epilepsy, defined as two or more unprovoked remote symptomatic seizures, was diagnosed in 4% of patients during the first year. The cumulative rate through 2 years of follow-up was 13%.
This study contains several important new observations for clinical practice, Dr. Beslow said. One involves the high rate of EEG-only seizures. Previously, the decision to place a child on continuous EEG monitoring following ICH was often based upon physician intuition, and monitoring was more likely in those who presented with seizures at the time of their stroke.
"We hope our findings will encourage clinicians to consider more routine use of continuous EEG monitoring in children with ICH," she said.
The conventional wisdom has been that children who don’t have seizures at the time of their ICH are at reduced likelihood of developing seizures or epilepsy later on; these data suggest otherwise. Also, the parents of a young child with ICH are always deeply distraught and desperate to know what will happen to their child in the future. Now there are concrete risk figures for use in counseling, Dr. Beslow added.
Nearly a dozen prespecified potential risk factors for remote symptomatic seizures and epilepsy were scrutinized in the study. Only one proved statistically significant: elevated intracranial pressure requiring urgent intervention. The investigators anticipate that epilepsy rates will increase at planned 5- and 10-year follow-up. In addition, the researchers plan to recruit additional patients with pediatric ICH in order to strengthen the validity of their findings.
This ongoing study is funded by the National Institutes of Health. Dr. Beslow reported having no relevant financial interests.