Tumor-associated epilepsy in patients with brain metastases: necrosis-to-tumor ratio forecasts postoperative seizure freedom.

Surgical resection is highly effective in the treatment of tumor-related epilepsy (TRE) in patients with brain metastases (BM). Nevertheless, some patients suffer from postoperative persistent epilepsy which negatively impacts health-related quality of life. Therefore, early identification of patients with potentially unfavorable seizure outcome after BM resection is important. Patients with TRE that had undergone surgery for BM at the authors' institution between 2013 and 2018 were analyzed with regard to preoperatively identifiable risk factors for unfavorable seizure outcome. Tumor tissue and tumor necrosis ratios were assessed volumetrically. According to the classification of the International League Against Epilepsy (ILAE), seizure outcome was categorized as favorable (ILAE 1) and unfavorable (ILAE 2-6) after 3 months in order to avoid potential interference with adjuvant cancer treatment. Among all 38 patients undergoing neurosurgical treatment for BM with concomitant TRE, 34 patients achieved a favorable seizure outcome (90%). Unfavorable seizure outcome was significantly associated with larger tumor volumes (p = 0.012), a midline shift > 7 mm (p = 0.025), and a necrosis/tumor volume ratio > 0.2 (p = 0.047). The present study identifies preoperatively collectable risk factors for unfavorable seizure outcome in patients with BM and TRE. This might enable to preselect for highly vulnerable patients with postoperative persistent epilepsy who might benefit from accompanying neuro-oncological expertise during further systemical treatment regimes.

The necessity for routine intensive care unit admission following elective craniotomy for epilepsy surgery: a retrospective single-center observational study.

OBJECTIVE: Traditionally, patients who underwent elective craniotomy for epilepsy surgery are monitored postoperatively in an intensive care unit (ICU) overnight in order to sufficiently respond to potential early postoperative complications. In the present study, the authors investigated the frequency of early postoperative events that entailed ICU monitoring in patients who had undergone elective craniotomy for epilepsy surgery. In a second step, they aimed at identifying pre- and intraoperative risk factors for the development of unfavorable events to distinguish those patients with the need for postoperative ICU monitoring at the earliest possible stage. METHODS: The authors performed a retrospective observational cohort study assessing patients with medically intractable epilepsy (n = 266) who had undergone elective craniotomy for epilepsy surgery between 2012 and 2019 at a tertiary care epilepsy center, excluding those patients who had undergone invasive diagnostic approaches and functional hemispherectomy. Postoperative complications were defined as any unfavorable postoperative surgical and/or anesthesiological event that required further ICU therapy within 48 hours following surgery. A multivariate analysis was performed to reveal preoperatively identifiable risk factors for postoperative adverse events requiring an ICU setting. RESULTS: Thirteen (4.9%) of 266 patients developed early postoperative adverse events that required further postoperative ICU care. The most prevalent event was a return to the operating room because of relevant postoperative intracranial hematoma (5 of 266 patients). Multivariate analysis revealed intraoperative blood loss ≥ 325 ml (OR 6.2, p = 0.012) and diabetes mellitus (OR 9.2, p = 0.029) as risk factors for unfavorable postoperative events requiring ICU therapy. CONCLUSIONS: The present study revealed routinely collectable risk factors that would allow the identification of patients with an elevated risk of postsurgical complications requiring a postoperative ICU stay following epilepsy surgery. These findings may offer guidance for a stepdown unit admission policy following epilepsy surgical interventions after an external validation of the results.

Temporal lobe epilepsy surgery: Piriform cortex resection impacts seizure control in the long-term.

OBJECTIVE: Recently, we showed that resection of at least 27% of the temporal part of piriform cortex (PiC) strongly correlated with seizure freedom 1 year following selective amygdalo-hippocampectomy (tsSAHE) in patients with mesial temporal lobe epilepsy (mTLE). However, the impact of PiC resection on long-term seizure outcome following tsSAHE is currently unknown. The aim of this study was to evaluate the impact of PiC resection on long-term seizure outcome in patients with mTLE treated with tsSAHE. METHODS: Between 2012 and 2017, 64 patients were included in the retrospective analysis. Long-term follow-up (FU) was defined as at least 2 years postoperatively. Seizure outcome was assessed according to the International League against Epilepsy (ILAE). The resected proportions of hippocampus, amygdala, and PiC were volumetrically assessed. RESULTS: The mean FU duration was 3.75 ± 1.61 years. Patients with ILAE class 1 revealed a significantly larger median proportion of resected PiC compared to patients with ILAE class 2-6 [46% (IQR 31-57) vs. 16% (IQR 6-38), p = 0.001]. Resected proportions of hippocampus and amygdala did not significantly differ for these groups. Among those patients with at least 27% resected proportion of PiC, there were significantly more patients with seizure freedom compared to the patients with <27% resected proportion of PiC (83% vs. 39%, p = 0.0007). CONCLUSIONS: Our results show a strong impact of the extent of PiC resection on long-term seizure outcome following tsSAHE in mTLE. The authors suggest the PiC to constitute a key target volume in tsSAHE to achieve seizure freedom in the long term.

A Validation Study for SHE Score for Acute Subdural Hematoma in the Elderly.

OBJECTIVE: The aim of this study was the verification of the Subdural Hematoma in the Elderly (SHE) score proposed by Alford et al. as a mortality predictor in patients older than 65 years with nontraumatic/minor trauma acute subdural hematoma (aSDH). Additionally, we evaluated further predictors associated with poor outcome. METHODS: Patients were scored according to age (1 point is given if patients were older than 80 years), GCS by admission (1 point for GCS 5-12, 2 points for GCS 3-4), and SDH volume (1 point for volume 50 mL). The sum of points determines the SHE score. Multivariate logistic regression analysis was performed to identify additional independent risk factors associated with 30-day mortality. RESULTS: We evaluated 131 patients with aSDH who were treated at our institution between 2008 and 2020. We observed the same 30-day mortality rates published by Alford et al.: SHE 0: 4.3% vs. 3.2%, p = 1.0; SHE 1: 12.2% vs. 13.1%, p = 1.0; SHE 2: 36.6% vs. 32.7%, p = 0.8; SHE 3: 97.1% vs. 95.7%, p = 1.0 and SHE 4: 100% vs. 100%, p = 1.0. Additionally, 18 patients who developed status epilepticus (SE) had a mortality of 100 percent regardless of the SHE score. The distribution of SE among the groups was: 1 for SHE 1, 6 for SHE 2, 9 for SHE 3, and 2 for SHE 4. The logistic regression showed the surgical evacuation to be the only significant risk factor for developing the seizure. All patients who developed SE underwent surgery (p = 0.0065). Furthermore, SHE 3 and 4 showed no difference regarding the outcome between surgical and conservative treatment. CONCLUSIONS: SHE score is a reliable mortality predictor for minor trauma acute subdural hematoma in elderly patients. In addition, we identified status epilepticus as a strong life-expectancy-limiting factor in patients undergoing surgical evacuation.

The Role of Intraoperative Image Guidance Systems (Three-Dimensional C-arm versus O-arm) in Spinal Surgery: Results of a Single-Center Study.

OBJECTIVE: Spinal dorsal instrumentation is an established treatment option for a range of spinal disorders. In combination with navigation, intraoperative fluoroscopy reduces the risk of incorrectly placing screws. This study aimed to evaluate the efficacy and validity of fluoroscopy (intraoperative navigation with three-dimensional rotation of C-arm vs. O-arm). METHODS: In this retrospective single-center study, 240 patients were included between July 2017 and April 2020. Intraoperative images were acquired using a Siemens-Arcadis Orbic 3D C-arm with a navigation system (Brainlab, AG, Munich, Germany) or using O-arm (Medtronic, Minneapolis, Minnesota, USA) with a navigation system (S7 StealthStation). Finally, we compared mismatches between intraoperative and postoperative computed tomography imaging results using Rampersaud-grade (A-D). RESULTS: A total of 1614 screws were included: 94 patients in the C-arm group (cAG) and 146 in the O-arm group (oAG). In cAG, 3% (n = 20) of the screws had to be replaced directly due to inadequate positioning with median or lateral breaches, and 3.5 % of screws in oAG (n = 35). An A-score was achieved for 85.7% in the cAG and 87.4% in the oAG. A B-score was found in 11.5% in the cAG and 11.9% in the oAG. In the cAG, a C-score was achieved for 2.5% and in oAG for 0.7%. For 0.3% of the screws, a D-score was found in cAG and for none in oAG. CONCLUSIONS: Our study shows that placement of screws using intraoperative imaging in combination with a navigation tool is accurate. Furthermore, navigation coupled with the O-arm had significant advantages in accuracy over navigation with 3D C-arm fluoroscopy. However, both systems offer a high level of accuracy.