Introduction: Seizures are an important presenting symptom and postoperative morbidity in glioblastoma patients.
Methods: We performed a retrospective study of 492 glioblastoma patients.
Results: Our cohort was 61.8% male and had mean age at operation of 61 (range 4-88). One-hundred and eighty-two (37%) patients presented with seizures. These patients were less likely to have headaches (30% vs. 41%; p=0.005) or motor deficits (17% vs 31%; p=0.009). Patients with seizures had a mean 31 days between presentation and surgery, which was significantly more than the 15 days in patients without seizures (P=0.0043). Tumor size for seizure vs. non-seizure patients was 3.4 vs 4.0 cm (P=0.001). Patients with IDH mutations were more likely to be cured of seizures (14% vs 2%; p=0.041).
In terms of postoperative seizures, sixty-three (15%) patients who did not have a preoperative seizure had a postoperative seizure. Seventeen of the sixty-three patients (30%) had seizures within two weeks of surgery and were considered early while the remaining 70% had late postoperative seizures. Compared to patients without early postop seizures, early postop seizure patients were more likely to have had post-operative hyponatremia (38% vs 14%; p=0.02) and have presented with motor deficits (53% vs 29%; p=0.04). Patients with >15% of Chromosome 10 deleted were more likely to have delayed seizures post-operatively (44% vs 23%; p=0.03), seizing a median 92 days (range: 9 to 411) after surgery.
Conclusions: Glioblastoma patients with seizures experience more time between presentation and surgery and are more likely to have smaller tumors and less likely to have headaches or motor deficits. Patients with IDH mutations are more likely to have their seizures cured with surgery. Variables such as post-operative hyponatremia and motor deficits predicted early seizures, while >15% deletion of Chromosome 10, which harbors both tumor suppressor genes and epilepsy-associated genes, predicted late postoperative seizures.
Patient Care: Seizures are an important and relatively common consequence of glioblastoma. These episodes may dramatically impact quality of life and alter clinical trajectories. Recognizing which patients are at increased risk, and therefore in need of close clinical follow-up, is clinically valuable information.
Learning Objectives: 1) Appreciate that seizures can occur at different times during glioblastoma treatment 2) recognize that seizures may derive from different pathological processes and therefore had different risk factors.