Effects of Levetiracetam and Lacosamide on survival and seizure control in IDH-wild type glioblastoma during temozolomide plus radiation adjuvant therapy

Introduction

There are no clear indications for the best choice of anti-seizure medications to control brain tumor related epilepsy. In vitro studies have shown an antitumoral effect of Levetiracetam and Lacosamide on glioblastoma IDH-wild type.

Research question

This study investigates whether the use of levetiracetam and/or lacosamide impacts survival rates. The secondary aim was to evaluate the efficacy of both ASMs in controlling seizures.

Materials and methods

In this observational retrospective single-cohort study, patients underwent chemoradiation protocol after GBM surgery. They were grouped as follows: (1) use of levetiracetam, (2) use of lacosamide, (3) simultaneous use of levetiracetam and lacosamide, (4) no ASM usage. Survival curves were plotted using the Kaplan-Meier method coupled with a log-rank test for difference assesments. To evaluate the pharmacological efficacy of post-operative seizure control, a negative binomial regression was conducted.

Results

The study included 272 patients, 174 of which underwent adjuvant chemoradiation treatment. Patients without ASM therapy had a non-significant longer median OS (compared to the other groups (log-rank = 0.37). The IRR of seizure relapse was 2.57 (p = 0.007) times higher in lacosamide users, and MGMT promoter methylation demonstrated a protective effect against postoperative seizure onset (p = 0.05), regardless of the aforementioned confounding factors.

Discussion and conclusions

In patients diagnosed with GBM IDH-WT undergoing chemoradiation therapy, the use of levetiracetam or lacosamide for controlling BTRE does not seem to modify survival. Lacosamide users exhibited a higher IRR of postoperative seizures compared to levetiracetam users, and MGMT promoter methylation appears to be a protective factor.

Management of Extramedullary Intradural Spinal Tumors: The Impact of Clinical Status, Intraoperative Neurophysiological Monitoring and Surgical Approach on Outcomes in a 12-Year Double-Center Experience

Objective: Intradural Extramedullary (IDEM) tumors are usually treated with surgical excision. The aim of this study was to investigate the impact on clinical outcomes of pre-surgical clinical conditions, intraoperative neurophysiological monitoring (IONM), surgical access to the spinal canal, histology, degree of resection and intra/postoperative complications.

Methods: This is a retrospective observational study analyzing data of patients suffering from IDEM tumors who underwent surgical treatment over a 12 year period in a double-center experience. Data were extracted from a prospectively maintained database and included: sex, age at diagnosis, clinical status according to the modified McCormick Scale (Grades I-V) at admission, discharge, and follow-up, tumor histology, type of surgical access to the spinal canal (bilateral laminectomy vs. monolateral laminectomy vs. laminoplasty), degree of surgical removal, use and type of IONM, occurrence and type of intraoperative complications, use of Ultrasonic Aspirator (CUSA), radiological follow-up.

Results: A total number of 249 patients was included with a mean follow-up of 48.3 months. Gross total resection was achieved in 210 patients (84.3%) mostly in Schwannomas (45.2%) and Meningiomas (40.4%). IONM was performed in 162 procedures (65%) and D-wave was recorded in 64.2% of all cervical and thoracic locations (99 patients). The linear regression diagram for McCormick grades before and after surgery (follow-up) showed a correlation between preoperative and postoperative clinical status. A statistically significant correlation was found between absence of worsening of clinical condition at follow-up and use of IONM at follow-up (p = 0.01) but not at discharge. No associations were found between the choice of surgical approach and the extent of resection (p = 0.79), the presence of recurrence or residual tumor (p = 0.14) or CSF leakage (p = 0.25). The extent of resection was not associated with the use of IONM (p = 0.91) or CUSA (p = 0.19).

Conclusion: A reliable prediction of clinical improvement could be made based on pre-operative clinical status. The use of IONM resulted in better clinical outcomes at follow-up (not at discharge), but no associations were found with the extent of resection. The use of minimally invasive approaches such as monolateral laminectomy showed to be effective and not associated with worse outcomes or increased complications.

Exploring the anatomy of negative motor areas (NMAs): Findings in awake surgery

Positive motor responses have been used in neurosurgery for the identification of motor structures. With the term "negative motor responses" (NMRs) a complete inhibition of movement without loss of muscle tone or consciousness is meant. Papers already exist in the literature regarding cortical areas in which such NMRs are evoked, the so-called "negative motor areas" (NMAs), but their location and functional meaning are still poorly understood. This paper discusses the anatomy of the NMAs of the human brain, in light of our brain mapping experience. 21 patients underwent awake surgery and direct electrical stimulation (DES) was performed using bipolar electrodes. Excision was interrupted when functional responses were intraoperatively identified through DES. The labeled mapping sites were recorded by photography prior to and following tumor resection. Results depicting a probabilistic map of negative motor network anatomy were retrospectively analyzed. Our findings strongly support the fact that the precentral gyrus, classical site of the of the Primary Motor Areas, is also strongly involved in generating NMRs. The distribution of NMAs was noted not to be as rigid as previously described, ranging in different brain areas with a somatotopic arrangement. Presented anatomical results are consistent with the literature, but the exact functional meaning of NMAs and their subcortical connectivity is still far from being completely understood.