Epileptic seizures and survival in early disease of grade 2 gliomas

Background and purpose:  The aims of this study were (i) to determine the correlation between seizure activity and the metabolic rate of the tumour measured by ¹¹C-methionine PET (MET PET) in patients with grade 2 gliomas, and (ii) to assess the prognostic impact of early seizure manifestations on patient survival.
Methods:  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.
Results:  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.
Conclusion:  The presence and termination of early seizure manifestations may be favourable prognostic factors in patients with low-grade gliomas.