Perioperative levetiracetam for seizure prophylaxis in seizure-naive brain tumor patients with focus on neurocognitive functioning.

INTRODUCTION: In seizure-naive brain tumor patients, the efficacy of perioperative prophylactic antiepileptic drug treatment remains controversial. In case of administration, the common preferred drug is levetiracetam (LEV) because of its favorable pharmacological profile. Research to date has not sufficiently determined how LEV affects cognition in the short term, as is the case in the perioperative period. The objective of this prospective study was to examine the neurocognitive functioning of seizure-naive brain tumor patients after receiving LEV perioperatively. METHODS: Fortythree patients with supratentorial brain tumor scheduled for surgery received LEV three days before until six days after surgery as seizure prophylaxis. Cognitive functioning (NeuroCogFX), LEV plasma-levels, hematotoxicity, side-effects, as well as health-related quality of life (HRQoL, Qolie31), were recorded preoperatively before (Baseline) and after onset of LEV (Pre-Op), 4-6 days postoperatively (Post-Op) and 21 days postoperatively (Follow-Up). RESULTS: No significant changes in cognitive functioning and HRQoL were seen after onset of preoperative LEV. There was a significant improvement of NeuroCogFX total-score at Follow-Up (p = 0.004) compared to Baseline. The overall-score Qolie31 showed simultaneous improvement patterns as cognitive functioning (p < 0.001). The most frequent side effect related to study drug was somnolence (in 28.6% of patients). CONCLUSIONS: A significant improvement of cognitive functioning, as well as an improvement in HRQoL, were detected postoperatively. This is presumably due to the debulking effect of the surgery. Nevertheless, LEV has no detrimental effect on cognitive functioning in the perioperative phase in seizure-naive brain tumor patients. TRIAL REGISTRATION: This study was registered prospectively (Date: 25/11/2015; EudraCT: 2015-003,916-19).

Nerve root herniation with entrapment in the facet joint gap after lumbar decompression surgery: a case presentation.

BACKGROUND: An incidental dural tear is a well-known complication during spine surgery. A rare consequence is a postoperative nerve root herniation. The purpose of this report is to describe a case of such a herniation with entrapment in the facet gap joint and to present the first MR images of this rare surgical complication. CASE PRESENTATION: We report a case of a patient who underwent lumbar decompression surgery and afterwards suffered a sudden intractable sciatica. Postoperative MRI showed a new facet joint gap effusion. During revision surgery an entrapped nerve root was found in the facet joint gap. In retrospective, the herniated nerve root is visible on postoperative MRI. CONCLUSION: This case report highlights a rare complication during spine surgery. This finding is important as signs suggestive for nerve root herniation can easily be overlooked on MRI. Furthermore, this represents the first MRI documentation of this complication.

Extent of spinal canal obliteration as prognostic factor for functional outcome in patients with spontaneous spinal epidural hematoma: a retrospective study.

BACKGROUND: Spontaneous spinal epidural hematoma (SSEDH) is a rare condition with potentially devastating consequences. Known prognostic factors are short time to surgery, preoperative neurologic condition, and age. The aim of this study was to investigate the impact of the transversal hematoma extent with its subsequent spinal canal obliteration on outcome in patients with SSEDH. METHODS: A retrospective study including all patients that underwent surgery due to SSEDH at the University Hospital of St. Poelten between 1/7/2005 and 30/6/2020 was conducted. The percentage of spinal canal obliteration at the level where the hematoma was most prominent was calculated and correlated to functional outcome. RESULTS: A total of 17 patients could be included in this study. Preoperative ASIA impairment scale showed positive correlation with postoperative outcome (p = 0.005). Patients with a favorable outcome (ASIA D and E) showed a statistically significant lower mean obliteration of the spinal canal by the hematoma with 46.4% (± 8%) in comparison to patients with an unfavorable outcome with 62.1% (± 6%, p = 0.001). A cut-off of 51% yielded a sensitivity and specificity for favorable outcome of 100% and 70% respectively (area under the ROC 0.93, p < 0.001). CONCLUSION: Preoperative percentage of spinal canal obliteration is statistically significant lower in patients with favorable outcome in surgically treated patients with spontaneous spinal epidural hematoma.

Microsurgical and endovascular treatment of un-ruptured cerebral aneurysms by European hybrid neurosurgeons to balance surgical skills and medical staff management.

BACKGROUND: In Europe, aneurysm treatment performed by dually trained neurosurgeons is extremely scarce. We provide outcome data for un-ruptured aneurysm patients treated at a European hybrid center to prove that hybrid neurosurgeons achieve clinical and angiographical results allowing to integrate hybrid neurosurgery into routine aneurysm treatment. This will not only help to maintain neurovascular microsurgical skills but will influence staff costs in related hospitals. METHODS: We retrospectively analyzed all consecutively treated un-ruptured aneurysm patients between 2000 and 2016. The decision-making took into account the pros and cons of both modalities and considered patient and aneurysm characteristics. Clinical outcome was assessed by the modified Rankin scale (mRS). Occlusion rates were stratified into grade I for 100%, grade II for 99-90%, and grade III for <90% occlusion. To account for the introduction of stents, two treatment periods (p1, 2000 to 2008; p2, 2009 to 2016) were defined. RESULTS: The study population consisted of 274 patients (median age 55 years) harboring 338 un-ruptured aneurysms. Microsurgery (MS) was performed in 51.8% and endovascular therapy (EVT) in 43.1%; 5.1% required combined treatment. Overall, 93% showed a favorable clinical outcome (mRS 0-2), 94.3% after MS and 91.5% after EVT. Grade I aneurysm occlusion was achieved in 82.6% patients, 91.9% after MS and 72.9% after EVT. Procedure-related complications occurred after MS in 5.6% and after EVT in 4.4% patients. Mortality was recorded for five (1.8%) patients, one patient after MS and four after EVT. For the EVT cohort, significant improvement from p1 to p2 was seen with clinical outcomes (P=0.030, RR = 0.905, CI: 0.8351-0.9802) and occlusion rates (P=0.039, RR = 0.6790, CI: 0.499-0.923). CONCLUSION: Hybrid neurosurgeons achieve qualified clinical and angiographic results. Dual training will allow to maintain neurovascular caseloads and preserve future aneurysm treatment within neurosurgery. Furthermore economic benefits could be observed in hospital management.

Aneurysm wall thickness measurements of experimental aneurysms: in vivo high-field MR imaging versus direct microscopy.

BACKGROUND: Thin cerebral aneurysm wall thickness (AWT) is connected to high aneurysm rupture risk. MR imaging of AWT leads to overestimations. The aim of the present study was to quantify MR inaccuracy by comparison with accurate light microscopic measurements. METHODS: In 13 experimental microsurgical bifurcation aneurysms in rabbits, 3 Tesla (3 T)-MR imaging using contrast-enhanced T1 Flash sequences (resolution: 0.4 × 0.4 × 1.5 mm³) was performed. The aneurysms were retrieved immediately after MR acquisition, cut longitudinally, and calibrated photographs were obtained. AWT (dome, neck) and parent vessel thickness (PVT) were measured on the MR images and microscopic photographs by independent investigators. All parameters were statistically compared (Wilcoxon test, Spearman correlation). RESULTS: AWT and PVT could be imaged and measured in all aneurysms with good quality. Comparison with the "real" light microscopic measurements showed a progressive tendency of MR AWT overestimation with smaller AWT: AWT at the dome (0.24 ± 0.06 mm vs. MR 0.30 ± 0.08 mm; p = 0.0078; R = 0.6125), AWT at the neck (0.25 ± 0.07 mm vs. MR 0.29 ± 0.07 mm; p = 0.0469; R = 0.7451), and PVT (0.46 ± 0.06 mm vs. MR 0.48 ± 0.06 mm; p = 0.5; R = 0.8568). CONCLUSION: In this experimental setting, 3 T-MR imaging of cerebral AWT showed unacceptable inaccuracies only below the image resolution threshold. Theoretically, AWT for clinical usage could be classified in ranges, defined by the maximum image resolution.

Repeated combined endovascular therapy with milrinone and nimodipine for the treatment of severe vasospasm: preliminary results.

BACKGROUND: Delayed vasospasm (VSP) following aneurysmal subarachnoid hemorrhage (aSAH) remains a major source of morbidity. Milrinone was recently suggested as an invasive VSP treatment option. It is a phosphodiesterase III inhibitor with vasodilating and additional positive inotrope and anti-inflammatory effects. METHODS: In this preliminary series, we included patients with severe VSP and unsuccessful maximum conservative therapy. Inclusion criteria were (1) transcranial Doppler (TCD) mean >180 cm/s; (2) increase of >50 % of TCD mean values within 6 h to values >150 cm/s; and/or (3) neurological deterioration (after exclusion of hemorrhage, hydrocephalus, and other systemic reasons). Patients received endovascular therapy with nimodipine 2 mg followed by milrinone 4-8 mg. Reinterventions were indicated aggressively in cases of persistent neurological deficits or persistent high mean TCD >180 cm/s. RESULTS: Of 121 consecutive aSAH patients, 16 (13.2 %) received endovascular VSP therapy. Of these, 11 patients (68.5 %) received ≥ 3 interventions (median 4; maximum 9); 14 (87.5 %) showed postinterventional angiographic improvement of vessel diameters; and 11 (68.5 %) showed improvement of their neurological deficits after a mean follow-up time of 4.5 months. No cardiovascular adverse events attributed to milrinone were observed. CONCLUSIONS: Milrinone may be a useful supplementary substance for endovascular VSP therapy. Aggressive reintervention indications did not cause additional adverse events.

Evaluation of cerebral aneurysm wall thickness in experimental aneurysms: comparison of 3T-MR imaging with direct microscopic measurements.

BACKGROUND: Thin aneurysm wall thickness (AWT) is thought to portend an elevated risk of intracranial aneurysm rupture. Magnetic resonance imaging (MRI) is biased by AWT overestimations. Previously, this suspected bias has been qualitatively described but never quantified. We aimed to quantify the overestimation of AWT by MRI when compared to the gold standard of AWT as measured by light microscopy of fresh aneurysm specimens (without any embedding procedure). This analysis should help to define the clinical potential of MRI estimates of AWT. METHODS: 3-Tesla (3T) MRI (contrast-enhanced T1 Flash sequences; resolution: 0.4 x 0.4 x 1.5 mm(3)) was performed in 13 experimental aneurysms. After MR acquisition, the aneurysms were retrieved, longitudinally sectioned and calibrated micrographs were obtained immediately. AWT at the dome, AWT at the neck and parent vessel wall thickness (PVT) were measured on precisely correlated MR-images and histologic micrographs by blinded independent investigators. Parameters were statistically compared (Wilcoxon test, Spearman's correlation). RESULTS: AWT was assessed and reliably measured using MRI. Interobserver variability was not significant for either method. MR overestimation was only significant below the image resolution threshold: AWT at the dome (0.24 ± 0.06 mm vs. MR 0.30 ± 0.08 mm; p = 0.0078; R = 0.6125), AWT at the neck (0.25 ± 0.07 mm vs. MR 0.29 ± 0.07 mm; p = 0.0469; R = 0.7451), PVT (0.46 ± 0.06 mm vs. MR 0.48 ± 0.06 mm; p = 0.5; R = 0.8568). CONCLUSION: In this experimental setting, MR overestimations were minimal (mean 0.02 mm) above the image resolution threshold. When AWT is classified in ranges defined by the MR resolution threshold, clinical usage may be beneficial. Further quantitative and comparative experimental and human studies are warranted to confirm these findings.

Experimental Broad-Based Curved Sidewall Aneurysms in Rabbits Mimicking Human Carotid Siphon Aneurysms: Proof of Feasibility and Comparability Using Computational Fluid Dynamics.

BACKGROUND/OBJECTIVE: Broad-based sidewall aneurysms of the carotid artery are primarily treated endovascularly. However, recurrence or rupture after treatment still poses a significant risk. Hence, reliable animal models mimicking this aneurysm type are essential for to evaluate the performance of new advanced endovascular devices. METHODS: Experimental aneurysms were created in 12 New Zealand white rabbits (2.5-3.5 kg). The human carotid siphon was mimicked with an end-to-end anastomosis of both common carotid arteries. A venous pouch was sutured on the convexity to mimic a broad-based side wall aneurysm. Patency and configuration were investigated 4 weeks postoperatively by 3-T magnetic resonance angiography. To compare flow conditions of broad-based sidewall aneurysms in rabbits and humans, exemplary computational fluid dynamics simulations were performed using species-specific blood viscosity values. RESULTS: We were able to achieve 0% peri- or postoperative mortality. Patency was confirmed by 3-T magnetic resonance angiography in 11 of 12 aneurysms (91.7%). Aneurysm lengths ranged from 6.4 to 9.8 mm and aneurysm necks from 7.3 to 9.8 mm. Computational fluid dynamics showed simple flow profiles with one vortex in rabbit as well as in human aneurysms. Wall shear stress rates were comparable using species-specific blood viscosity values (rabbit mean 1.65 Pa vs. human mean 1.7 Pa). CONCLUSIONS: The broad-based curved sidewall aneurysm model mimicking the carotid siphon showed high aneurysm patency rates with low morbidity. High comparability with human flow patterns and human intranaeurysmal biomechanical forces was shown using simulations.

Open Microsurgical Cerebral Aneurysm Treatment After Failed Endovascular Therapy: An Evaluation of Aneurysm Treatment Frequencies in All Neurovascular Centers Across Austria and the Czech Republic Over 20 Years.

BACKGROUND AND OBJECTIVES: Endovascular treatment of cerebral aneurysms has tremendously advanced over the past decades. Nevertheless, aneurysm residual and recurrence remain challenges after embolization. The objective of this study was to elucidate the portion of embolized aneurysms requiring open surgery and evaluate whether newer endovascular treatments have changed the need for open surgery after failed embolization. METHODS: All 15 cerebrovascular centers in Austria and the Czech Republic provided overall aneurysm treatment frequency data and retrospectively reviewed consecutive cerebral aneurysms treated with open surgical treatment after failure of embolization from 2000 to 2022. All endovascular modalities were included. RESULTS: On average, 1362 aneurysms were treated annually in the 2 countries. The incidence increased from 0.006% in 2005 to 0.008% in 2020 in the overall population. Open surgery after failed endovascular intervention was necessary in 128 aneurysms (0.8%), a proportion that remained constant over time. Subarachnoid hemorrhage was the initial presentation in 70.3% of aneurysms. The most common location was the anterior communicating artery region (40.6%), followed by the middle cerebral artery (25.0%). The median diameter was 6 mm (2-32). Initial endovascular treatment included coiling (107 aneurysms), balloon-assist (10), stent-assist (4), intrasaccular device (3), flow diversion (2), and others (2). Complete occlusion after initial embolization was recorded in 40.6%. Seventy-one percent of aneurysms were operated within 3 years after embolization. In 7%, the indication for surgery was (re-)rupture and, in 88.3%, reperfusion. Device removal was performed in 16.4%. Symptomatic intraoperative and postoperative complications occurred in 10.2%. Complete aneurysm occlusion after open surgery was achieved in 94%. CONCLUSION: Open surgery remains a rare indication for cerebral aneurysms after failed endovascular embolization even in the age of novel endovascular technology, such as flow diverters and intrasaccular devices. Regardless, it is mostly performed for ruptured aneurysms initially treated with primary coiling that are in the anterior circulation.

Three-dimensional susceptibility-weighted imaging at 7 T using fractal-based quantitative analysis to grade gliomas.

INTRODUCTION: Susceptibility-weighted imaging (SWI) with high- and ultra-high-field magnetic resonance is a very helpful tool for evaluating brain gliomas and intratumoral structures, including microvasculature. Here, we test whether objective quantification of intratumoral SWI patterns by applying fractal analysis can offer reliable indexes capable of differentiating glial tumor grades. METHODS: Thirty-six patients affected by brain gliomas (grades II-IV, according to the WHO classification system) underwent MRI at 7 T using a SWI protocol. All images were collected and analyzed by applying a computer-aided fractal image analysis, which applies the fractal dimension as a measure of geometrical complexity of intratumoral SWI patterns. The results were subsequently statistically correlated to the histopathological tumor grade. RESULTS: The mean value of the fractal dimension of the intratumoral SWI patterns was 2.086 ± 0.413. We found a trend of higher fractal dimension values in groups of higher histologic grade. The values ranged from a mean value of 1.682 ± 0.278 for grade II gliomas to 2.247 ± 0.358 for grade IV gliomas (p = 0.013); there was an overall statistically significant difference between histopathological groups. CONCLUSION: The present study confirms that SWI at 7 T is a useful method for detecting intratumoral vascular architecture of brain gliomas and that SWI pattern quantification by means of fractal dimension offers a potential objective morphometric image biomarker of tumor grade.