Childhood brain tumor survivors are susceptible to seizures, according to a study published online ahead of print August 31 in Epilepsia. Among 298 survivors of pediatric brain tumors, seizures were seen in 24% at presentation and were ongoing in 14%. “Seizures are one of the most significant neurologic complications of childhood brain tumors, as they can occur frequently at any time from diagnosis to years after completion of treatment,” said Nicole J. Ullrich, MD, PhD, Director of Neurologic Neuro-Oncology at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center.
Dr. Ullrich and colleagues conducted a retrospective, longitudinal review of consecutive patients examined during a 12-month period who were at least two years post initial diagnosis of a brain tumor. Data collected included age at diagnosis, length of follow-up, extent of initial resection, tumor histology, and treatment modalities. The timing and frequency of seizures, seizure semiology, EEG results, and anticonvulsant use also were recorded. Average duration of follow-up was 7.6 years.
The study cohort included 298 patients; nearly half (140) were female. Initial surgical resection was gross-total in 109 patients and subtotal in 143. Twenty-nine patients underwent biopsy alone, and 17 had no surgical intervention. Tumor location included posterior fossa in 104 (36%), midline in 98 (34%), cortical in 85 (29%), and other in 11 (3%). The most frequent diagnoses were low-grade glioma, medulloblastoma, and ependyoma.
Thirty patients had seizures at the time of tumor diagnosis (10% of the entire cohort, 42% of those with seizures), whereas seizure onset occurred during treatment in 12 patients (3% of entire cohort, 17% of those with seizures) and more than two years after completion of treatment in 16 patients (5.3% of entire cohort, 22% of those with seizures). Ongoing seizures at the time of most recent follow-up were present in 43 patients (14% of entire cohort, 58% of those with seizures).
Factors predisposing to seizures included tumor pathology (low- or high-grade glioma, glioneuronal tumor), cortical location, and subtotal initial resection of the tumor. Seizures were mostly well controlled by antiepileptic drugs.
Dr. Ullrich and colleagues proposed that earlier identification of seizure-eliciting factors in tumor survivors could help in weaning the patients from anticonvulsant medication to reduce the probability of continuing seizures sooner after treatment.