Objective: Seizures present in 50-90 % of cases with low-grade brain tumors. Frontal lobe epilepsy is associated with dismal seizure outcomes compared to temporal lobe epilepsy. Our objective is to conduct a systematic review, report our case series, and perform a pooled analysis of clinical predictors of seizure outcomes in frontal lobe low-grade brain tumors.
Methods: Searches of five electronic databases from January 1990 to June 2022 were reviewed following PRISMA guidelines. Individual patient data was extracted from 22 articles that fit the inclusion criteria. A single-surgeon case series from our institution was also retrospectively reviewed and analyzed through a pooled cohort of 127 surgically treated patients with frontal lobe low-grade brain tumors.
Results: The mean age at surgery was 30.8 years, with 50.4 % of patients diagnosed as oligodendrogliomas. The majority of patients (81.1 %) were seizure-free after surgery (Engel I). On the multivariate analysis, gross total resection (GTR) (OR = 8.77, 95 % CI: 1.99-47.91, p = 0.006) and awake resection (OR = 9.94, 95 % CI: 1.93-87.81, p = 0.015) were associated with seizure-free outcome. A Kaplan-Meier curve showed that the probability of seizure freedom fell to 92.6 % at 3 months, and to 85.5 % at 27.3 months after surgery.
Conclusion: Epilepsy from tumor origin demands a balance between oncological management and epilepsy cure. Our pooled analysis suggests that GTR and awake resections are positive predictive factors for an Engel I at more than 6 months follow-up. To validate these findings, a longer-term follow-up and larger cohorts are needed.
Keywords: Brain tumor; Epilepsy; Frontal lobe; Glioma; Seizure.
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