RESUMO
PURPOSE: Epilepsy is a common complication of gliomas. The diagnosis of nonconvulsive status epilepticus (NCSE) is challenging because it causes impaired consciousness and mimics glioma progression. NCSE complication rate in the general brain tumor patient population is approximately 2%. However, there are no reports focusing on NCSE in glioma patient population. This study aimed to reveal the epidemiology and features of NCSE in glioma patients to enable appropriate diagnosis. METHODS: We enrolled 108 consecutive glioma patients (45 female, 63 male) who underwent their first surgery between April 2013 and May 2019 at our institution. We retrospectively investigated glioma patients diagnosed with tumor-related epilepsy (TRE) or NCSE to explore disease frequency of TRE/NCSE and patient background. NCSE treatment approaches and Karnofsky Performance Status Scale (KPS) changes following NCSE were surveyed. NCSE diagnosis was confirmed using the modified Salzburg Consensus Criteria (mSCC). RESULTS: Sixty-one out of 108 glioma patients experienced TRE (56%), and five (4.6%) were diagnosed with NCSE (2 female, 3 male; mean age, 57 years old; WHO grade II 1, grade III 2, grade IV 2). All NCSE cases were controlled by stage 2 status epilepticus treatment as recommended in the Clinical Practice Guidelines for Epilepsy by the Japan Epilepsy Society. The KPS score significantly decreased after NCSE. CONCLUSION: Higher prevalence of NCSE in glioma patients was observed. The KPS score significantly decreased after NCSE. Actively taking electroencephalograms analyzed by mSCC may facilitate accurate NCSE diagnosis and improve the activities of daily living in glioma patients.
RESUMO
PURPOSE: Intraoperative electrocorticography (ECoG) in the parahippocampal gyrus is sometimes used as a substitute for intraoperative ECoG in the hippocampus. This study aimed to elucidate the validity of parahippocampal ECoG as an indicator of hippocampal epileptogenicity. METHODS: We retrospectively identified 10 patients with drug-resistant unilateral mesial temporal lobe epilepsy who achieved Engel class I or II after anteromedial temporal lobectomy. Intraoperative ECoG was recorded in the parahippocampal gyrus and hippocampal alveus at sevoflurane concentrations of 1.5-3.0%. We sought to identify the sevoflurane proconvulsant effects on spikes and high-frequency oscillations (HFOs) on spikes in the epileptogenic area. The number of spikes and number of HFOs superimposed on spikes were counted in ECoG recordings of the parahippocampal gyrus, hippocampal alveus, and lateral temporal lobe, and analyzed using two-way repeated-measures analysis of variance. RESULTS: The number of spikes and number of HFOs superimposed on spikes significantly increased as the sevoflurane concentration increased in both the hippocampal alveus and parahippocampal gyrus (spike, p < 0.001; ripple, p < 0.001; Fast ripple (FR), p < 0.001), and the pattern of increase was similar in these two areas. The number of spikes and number of HFOs on spikes were statistically higher in the hippocampal alveus than in the parahippocampal gyrus (spike, p = 0.004; ripple, p = 0.005; FR, p = 0.001). There were almost no spikes or HFOs on spikes in the lateral temporal lobe at sevoflurane concentrations in the range of 1.5-2.5%. CONCLUSIONS: Intraoperative ECoG in the parahippocampal gyrus can serve as an indicator of hippocampal epileptogenicity.