Midtveisevaluering Kristin M. Knudsen-Baas

Epilepsy and epilepsy treatment in adult patients with glioma

Gliomas arise from glial or precursor cells and represent about 40% of all new brain tumors. Epileptic seizures may occur as an initial symptom that leads to the diagnosis of the tumor, or later during the disease. The risk of epileptic seizures is 70-90% for patients with low grade glioma (LGG) and 30-60% for patients with high grade glioma (HGG).

Glioblastoma (GBM) is the most aggressive, but also the most common, malignant primary brain tumor in adults. A debated issue is whether epilepsy and using anti-epileptic drugs (AEDs) is associated with improved prognosis in GBM. Data from the Cancer registry of Norway and The Norwegian Prescription Database were used in this study to obtain an unselected, national study population. We found no significant survival benefit in patients with GBM neither from having epilepsy nor from treatment with six separate AEDs.

Status epilepticus (SE) is prolonged seizure activity, or seizures which recur before clinical recovery from the preceding seizure. In a prospective study of patients with glioma and epilepsy in Western Norway, SE was more frequent in HGG than LGG. Patients with a stable glioma had SE as often as patients with untreated tumor or tumor in progression. Response to treatment was good, and SE triggered by tumor progression was not more refractory to treatment. To prevent worsened outcome, SE secondary to glioma must be treated as aggressively as other SE.

Although the median survival time for LGG may extend to more than 10 years, these patients cannot be cured of their disease. Quality of life is reported to be low, but to what extent medication is prescribed to treat depression and anxiety is not known. We further plan to investigate medication use and comorbidity in patients with LGG, with and without secondary epilepsy.