Epileptic seizures and survival in early disease of grade 2 gliomas

The aims of this study were (i) to determine the correlation between seizure activity and the metabolic rate of the tumour measured by C-11-methionine PET (MET PET) in patients with grade 2 gliomas, and (ii) to assess the prognostic impact of early seizure manifestations on patient survival. In this retrospective review, early seizure manifestations were studied in 101 patients with supratentorial grade 2 gliomas subjected to MET PET as part of the pre-treatment tumour investigation. Seizure manifestations as a variable was then used in multivariate survival analyses, together with established prognostic factors for this patient group. Of all 101 cases, 88 patients had seizures at tumour presentation. Forty-seven were seizure free at the early stage of the disease, whereas 54 had recurrent seizures. Patients with seizures at tumour presentation had a more favourable outcome before and after (P = 0.006) adjustment for conventional prognostic factors. However, for those who continued to have seizures early in the disease, the outcome was worse (P = 0.003). We found no significant correlation between MET PET and the seizure manifestations of the patients. The presence and termination of early seizure manifestations may be favourable prognostic factors in patients with low-grade gliomas.