Intracranial Surgery Research Articles

Feasibility of low-dose dexmedetomidine for prevention of postoperative delirium after intracranial operations: a pilot randomized controlled trial

BackgroundClinical trials have shown that dexmedetomidine might decrease the occurrence of postoperative delirium after major surgery, but neurosurgical patients were excluded from these studies. We aimed to determine the feasibility of conducting a full-scale randomized controlled trial of the effect of prophylactic low-dose dexmedetomidine on postoperative delirium in patients after elective intracranial operation for brain tumors.MethodsIn this single-center, parallel-arm pilot randomized controlled trial, adult patients who underwent an elective intracranial operation for brain tumors were recruited. Dexmedetomidine (0.1 μg/kg/hour) or placebo was continuously infused from intensive care unit (ICU) admission on the day of surgery until 08:00 AM on postoperative day one. Adverse events during the study-drug administration were recorded. The primary feasibility endpoint was the occurrence of study-drug interruption. Delirium was assessed twice daily with the Confusion Assessment Method for the ICU during the first five postoperative days. The assessable rate of delirium evaluation was documented.ResultsSixty participants were randomly assigned to receive either dexmedetomidine (n = 30) or placebo (n = 30). The study-drug was stopped in two patients (6.7%) in the placebo group due to desaturation after new-onset unconsciousness and an unplanned reoperation for hematoma evacuation and in one patient (3.3%) in the dexmedetomidine group due to unplanned discharge from the ICU. The absolute difference (95% confidence interval) of study-drug interruption between the two groups was 3.3% (− 18.6 to 12.0%), with a noninferiority P value of 0.009. During the study-drug infusion, no bradycardia occurred, and hypotension occurred in one patient (3.3%) in the dexmedetomidine group. Dexmedetomidine tended to decrease the incidence of tachycardia (10.0% vs. 23.3%) and hypertension (3.3% vs. 23.3%). Respiratory depression, desaturation, and unconsciousness occurred in the same patient with study-drug interruption in the placebo group (3.3%). Delirium was evaluated 600 times, of which 590 (98.3%) attempts were assessable except in one patient in the placebo group who remained in a coma after an unplanned reoperation.ConclusionsThe low rate of study-drug interruption and high assessable rate of delirium evaluation supported a fully powered trial to determine the effectiveness of low-dose dexmedetomidine on postoperative delirium in patients after intracranial operation for brain tumors.Trial registrationThe trial was registered at ClinicalTrials.gov (NCT04494828) on 31/07/2020.

Tube feeding in patients with dementia is associated with a longer palliative care unit stay

AbstractBackgroundTube feeding (TF) was reported to alter the length of stay (LOS) in a palliative care unit (PCU) in patients with dementia. Admission of dementia patients to the PCU for many reasons including respite is tried to be kept as short as possible due to limited reimbursement in Turkey. Our past observations in our unit have suggested that patients with dementia on TF may be prone to a longer stay in the PCU. Therefore, our objective in this study was to explore the association of TF with the LOS in the PCU in patients with home discharge.MethodIn this single center study at a PCU of a tertiary training hospital, we retrospectively enrolled patients with dementia with a diagnosis on admission, between April 2017 and December 2020. Subjects with a history of intracranial surgery, brain tumors, hemiplegic stroke, hypoxic brain injury, and other neurodegenerative diseases were excluded. Very early (within 4 days) or extremely late (beyond 45 days of hospitalization) discharges were also excluded. The association between TF and LOS in the PCU was examined using logistic regression analysis.ResultThe study included 71 home discharges [mean (SD) age: 82.5 (7.0) years], females 58.1%]. Median (IQR) LOS was 15 (13.0) days (4‐44), and 45 patients (63.4%) were on TF. Median age, gender, and the ration of cancer, infectious etiology, renal failure, hypertension, diabetes mellitus, composite cardiovascular disease, sleep disturbance, depression symptoms, and pain (VAS≥1) were similar patients with and without TF. All patients on TF were bed‐bound and had more pressure ulcers (73.2% vs. 50%) compared to those without TF. Multivariate logistic regression analysis showed that controlling for study covariates TF on admission or TF placement in the PCU was independently associated with highest tertile of LOS in the PCU (OR:4.29, 95%CI: 1.03 ‐ 17.77, P=0.045, Nagelkerke R2=%28.5, Hosöer Lemeshow test p=0.643).ConclusionThe present study showed that, in patients with an established diagnosis of dementia, TF is common and independently associated with a longer length of PCU stay. Nevertheless, the study was underpowered and the results deserve confirmation in larger studies.

Intraoperative Ultrasound Applications in Intracranial Surgery.

The methods and use of intraoperative ultrasound in 33 canine and five feline patients and its ability to localize and identify anatomical structures and pathological lesions in canines and felines undergoing intracranial surgery are described from a case series. All were client-owned referral patients admitted for neurologic evaluation, with an advanced imaging diagnosis of an intracranial lesion, and underwent surgical biopsy or surgical removal of the lesion. Medical records, retrieval and review of imaging reports, and characterization of findings for all canine and feline patients show that intraoperative ultrasound guidance was used in intracranial procedures during the period of 2012 and 2019. Twenty-nine of the canine patients had intracranial tumors. The remainder had various other conditions requiring intracranial intervention. Three of the feline patients had meningiomas, one had a depressed skull fracture, and one had an epidural hematoma. The tumors appeared hyperechoic on intraoperative ultrasound with the exception of cystic portions of the masses and correlated with the size and location seen on advanced imaging. Statistical comparison of the size of images seen on ultrasound and on MRI for 20 of the canine tumors revealed no statistical differences. Neuroanatomical structures, including vascular components, were easily identified, and tumor images correlated well with preoperative advanced imaging. The authors conclude that intraoperative ultrasound is a valuable asset in intracranial mass removals and can augment surgical guidance in a variety of intracranial disorders that require surgery. This is the first known publication in veterinary surgery of using intraoperative ultrasound as a tool in the operating theater to identify, localize, and monitor the removal/biopsy of intracranial lesions in small animals undergoing craniotomy/craniectomy.

Underutilization of advanced presurgical studies and high rates of vagus nerve stimulation for drug-resistant epilepsy: a single-center experience and recommendations.

Epilepsy surgery continues to be profoundly underutilized despite its safety and effectiveness. We sought to investigate factors that may contribute to this phenomenon, with a particular focus on the antecedent underutilization of appropriate preoperative studies. We reviewed patient data from a pediatric epilepsy clinic over an 18-month period. Patients with drug-resistant epilepsy (DRE) were categorized according to brain magnetic resonance imaging (MRI) findings (lesional, MRI-negative, or multifocal abnormalities) and type of epilepsy diagnosis based on semiology and electroencephalography (EEG) (focal or generalized). We then analyzed the rates of diagnostic test utilization, surgical referral, and subsequent epilepsy surgery as well as vagus nerve stimulation (VNS). Of the 249 patients with a diagnosis of epilepsy, 138 (55.4%) were found to have DRE. Excluding the 10 patients with DRE who did not undergo MRI, 76 patients (59.4%) were found to be MRI-negative (non-lesional epilepsy), 37 patients (28.9%) were found to have multifocal abnormalities, and 15 patients (11.7%) were found to have a single epileptogenic lesion on MRI (lesional epilepsy). Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) were each completed in nine patients (7.0%) and magnetoencephalography (MEG) in four patients (3.1%). Despite the low utilization rate of adjunctive studies, over half (56.3%) ultimately underwent VNS alone, and 8.6% ultimately underwent definitive intracranial resection or disconnection surgery. The underutilization of appropriate non-invasive, presurgical testing in patients with focal DRE may in part explain the continued underutilization of definitive, resective/disconnective surgery. For patients without access to a high-volume, multidisciplinary surgical epilepsy center, adjunctive presurgical studies [e.g., PET, SPECT, MEG, electrical source imaging (ESI), EEG-functional magnetic resonance imaging (fMRI)], even when available, are rarely ordered, and this may contribute to excessive rates of VNS in lieu of definitive intracranial surgery.

EPCO-01. MOLECULAR PROFILING OF SPINAL CORD EPENDYMOMA

Abstract BACKGROUND Ependymomas are currently classified into 9 subgroups by DNA methylation profiles. Although spinal cord ependymoma (SP-EPN) is distinct from other tumors, diversity within SP-EPN is still unclear. Here, we used transcriptomic and epigenomic profiles to investigate the diversity among Japanese SP-EPN cases. MATERIALS AND METHODS We analyzed 57 SP-EPN patients (32 males and 25 females, aged from 18 to 78 years, median: 52), including two cases of neurofibromatosis type 2, five cases of grade 3 (WHO grade). We obtained transcriptome (RNA-seq) and DNA methylation (Infinium Methylation EPIC array) data from fresh frozen specimens of SP-EPN resected at the University of Tokyo Hospital and our collaborative groups. RESULTS Three cases had a previous intracranial ependymoma operation. Hierarchical clustering of the DNA methylation data showed that these three cases of intracranial origin as a different cluster from spinal origin. The 45 grade 2 spinal ependymoma showed a relatively homogenous methylation pattern. However, the methylation status of HOX gene cluster regions is compatible with the segment of origin, which reflects the cells of origins are derived after the determination of segment identity. RNA sequencing of 57 cases revealed two subgroups within grade 2. Gene ontology analysis of differentially expressed genes suggested the difference in metabolic state such as rRNA translation and mitochondrial respiration between the two expression subgroups. CONCLUSION Epigenetic analysis indicated the accurate body segment origin of SP-EPN. We observed that metabolic states could divide grade 2 spinal cord ependymoma into 2 subgroups and will present the relationship to clinicopathological information.

Severity Assessment of Complex and Repeated Intracranial Surgery in Rats

Introduction: Evidence-based grading of the impact of intracranial surgery on rat’s well-being is important for ethical and legal reasons. We assessed the severity of complex and repeated intracranial surgery in a 6-hydroxydopamine (6-OHDA) Parkinson’s rat model with subsequent intracranial electrode implantation and in an intracranial tumor model with subsequent resection. Methods: Stereotactic surgery was performed in adult male rats with the same general anesthesia and perioperative pain management. In Parkinson’s model, Sprague Dawley rats received unilateral injection of 6-OHDA (n = 11) or vehicle (n = 7) into the medial forebrain bundle as first operation (1st OP). After four weeks, neural electrodes were implanted in all rats as second operation (2nd OP). For tumor formation, BDIX/UlmHanZtm rats (n = 8) received frontocortical injection of BT4Ca cells as 1st OP, followed by tumor resection as 2nd OP after one week. Multiple measures severity assessment was done two days before and four days after surgery in all rats, comprising clinical scoring, body weight, and detailed behavioral screening. To include a condition with a known burden, rats with intracranial tumors were additionally assessed up to a predefined humane endpoint that has previously been classified as “moderate”. Results: After the 1st OP, only 6-OHDA injection resulted in transient elevated clinical scores, a mild long-lasting weight reduction, and motor disturbances. After the second surgery, body weight was transiently reduced in all groups. All other parameters showed variable results. Principal component analysis showed a separation from the preoperative state driven by motor-related parameters after 6-OHDA injection, while separation after electrode implantation and more clearly after tumor resection was driven by pain-related parameters, although not reaching the level of the humane endpoint of our tumor model. Conclusion: Overall, cranial surgery of different complexity only transiently and rather mildly affects rat’s well-being. Multiple measures assessment allows the differentiation of model-related motor disturbances in Parkinson’s model from potentially pain-related conditions after tumor resection and electrode implantation.

Resting-State Functional Magnetic Resonance Imaging Networks as a Quantitative Metric for Impact of Neurosurgical Interventions.

Objective: Resting-state functional MRI (rs-fMRI) has been used to evaluate brain network connectivity as a result of intracranial surgery but has not been used to compare different neurosurgical procedures. Laser interstitial thermal therapy (LITT) is an alternative to conventional craniotomy for the treatment of brain lesions such as tumors and epileptogenic foci. While LITT is thought of as minimally invasive, its effect on the functional organization of the brain is still under active investigation and its impact on network changes compared to conventional craniotomy has not yet been explored. We describe a novel computational method for quantifying and comparing the impact of two neurosurgical procedures on brain functional connectivity.Methods: We used a previously described seed-based correlation analysis to generate resting-state network (RSN) correlation matrices, and compared changes in correlation patterns within and across RSNs between LITT and conventional craniotomy for treatment of 24 patients with singular intracranial tumors at our institution between 2014 and 2017. Specifically, we analyzed the differences in patient-specific changes in the within-hemisphere correlation patterns of the contralesional hemisphere.Results: In a post-operative follow-up period up to 2 years within-hemisphere connectivity of the contralesional hemisphere after surgery was more highly correlated to the pre-operative state in LITT patients when compared to craniotomy patients (P = 0.0287). Moreover, 4 out of 11 individual RSNs demonstrated significantly higher degrees of correlation between pre-operative and post-operative network connectivity in patients who underwent LITT (all P < 0.05).Conclusion: Rs-fMRI may be used as a quantitative metric to determine the impact of different neurosurgical procedures on brain functional connectivity. Global and individual network connectivity in the contralesional hemisphere may be more highly preserved after LITT when compared to craniotomy for the treatment of brain tumors.

Anatomical evaluation of the craniometric points and dimensions among adult’s populations of the South-Eastern Nigerians and its implication for intracranial surgical procedures

Background: The understanding of Craniometry with its associated craniometric points and dimensions have found immense applicable relevance in anthropology and neuroscience, ranging from growth determination, estimation of cranial deformities, personal biological profile identification and facial reconstructive surgeries, analysis of evolution of the human species in archeology as well as age variations. Objective: The aim of this study was to evaluate the craniometric dimensions among adults’ subjects in Eastern Nigerian State. Methods: Research data was collected from Computed Tomography scans in the Radiological Department of Federal Medical Centre, Umuahia, Nigeria with strict adherence to inclusive and exclusive factors. A total number of 150 human CT scans were used in the findings. Craniometric parameters were calculated - derived from the two and three coordinate points for linear and angular measurements respectively. Results: Results revealed that age group 36-45 had the lowest cranial parameters and age group 56-65 had the highest cranial parameters. Conclusion: It was concluded that cranial parameters does not increase as age increases throughout life. The study findings will be useful to the anatomists, anthropologists and neuroscientists.

Three-staged stereotactic radiosurgery for brain metastases: a single institution experience

Abstract Aims Stereotactic radiosurgery (SRS) using the Leksell Gamma Knife system is a commonly used modality for the treatment of brain metastases (BMs). As the size of the target volume (TV) increases, so too does the dose of radiation delivered to surrounding healthy tissue. Large BMs are therefore a contraindication to the use of SRS. Critical organs adjacent to the TV may also be a contraindication to SRS. Staged SRS was proposed as a novel method of delivering three SRS treatments at a reduced radiation dose with a gap of two weeks between each session as a way of shrinking the TV. This allows treatment of TVs otherwise considered untreatable with standard, single-fraction SRS. Little data exists in the literature as to its efficacy. The objective of this study was to evaluate the efficacy of this novel approach and to identify factors which may predict treatment failure. Method A retrospective analysis was undertaken at a single, tertiary Gamma Knife centre. All patients who underwent treatment of their BMs with three-staged Gamma Knife SRS from January 2014 to December 2020 were identified and included. Patient demographics and primary cancer status was ascertained. SRS treatment details for each lesion were collected, including TV, dose and dosimetric data. The percentage reduction in volume of the TVs between the first and second stage, the second and third stage and the first and third stage were calculated. Follow-up data was collected to include follow-up imaging, further intracranial treatments received and survival status. The percentage reduction in volume between each stage was demonstrated on box-and-whisker plots. Statistical significance in reduction in TV between each stage was ascertained by paired samples T-tests. Correlation between initial TV size and percentage reduction post-SRS was determined by a correlation coefficient. Differences were deemed significant with p-values &amp;lt;0.05. Results 12 patients with 14 staged BMs were identified and included. The median age was 61.5 (range 45-79). Seven had a primary malignancy of breast cancer, five non-small cell lung cancer, one melanoma and one colorectal. Median follow-up was 140.5 days (range 10-821). Median TV was 7.44cc (range 1.14-21.53). All TVs received 10Gy at each stage. The median percentage reduction in size of the TV was 7.41% between 1st-2nd stage (range -16.0-42.49%, p-value 0.06), 19.47% between 2nd-3rd stage (range -5.38-53.53%, p-value &amp;lt;0.01) and 24.25% between 1st-3rd stage (range 10.69-68.67%, p-value &amp;lt;0.01). The correlation coefficient between initial TV size and percentage reduction post-SRS was -0.41 (p-value 0.07). 13/14 lesions showed a partial response on first follow-up scan post-SRS, 1/14 lesions showed a mixed response. One patient died 184 days from completion of treatment but without intracranial progression. Two patients had salvage intracranial surgery, 154 and 536 days from completion of treatment respectively. Conclusion Three-staged Gamma Knife is shown to be effective at shrinking the TV and can therefore be used to treat lesions otherwise considered unsuitable for SRS. The presence of extra-cranial metastases did not predict for poor outcomes. Though local control with SRS is thought to diminish with increasing TV size, all staged lesions showed a reduction in size between first and last treatment, and no significant effect was seen between initial TV size and percentage reduction in TV. No patients experienced disease progression on first follow up scan, with 13 of 14 lesions showing disease response. There were only two cases of intracranial progression, with one occurring 536 days post-SRS. Though limited by small numbers and short median follow up period, our data demonstrate encouraging results for three-stage SRS for lesions otherwise unsuitable for single fraction treatment, and should lead to further study.

Cerebral oxygenation assessed by near-infrared spectroscopy in the sitting and prone positions during posterior fossa surgery: a prospective, randomized clinical study

ObjectivesSitting position (SP) or prone position (PP) are used for posterior fossa surgery. The SP induced reduction in cerebral blood flow and cerebral oxygen saturation (rSO2) has been shown in shoulder surgeries, but there is not enough data in intracranial tumor surgery. Studies showed that PP is safe in terms of cerebral oxygen saturation in patients undergoing spinal surgery. Our hypothesis is that the SP may improve cerebral oxygenation in the patients with intracranial pathologies due to reduction in intracranial pressure. Therefore, we compared the effects of the SP and PP on rSO2 in patients undergoing posterior fossa tumor surgery. MethodsData were collected patients undergoing posterior fossa surgery, 20 patients in SP compared to 21 patients in PP. The rSO2 was assessed using INVOS monitor. Heart rate (HR), mean arterial pressure (MAP), EtCO2, BIS, and bilateral rSO2 were recorded preoperatively, and at 5, 8, and 11.ßminutes after the intubation and every 3.ßminutes after patient positioning until the initial surgical incision. ResultsCerebral oxygenation slowly reduced in both the sitting and prone position patients following the positioning (p.ß<.ß0.002), without any difference between the groups. The HR and MAP were lower in the sitting SP after positioning compared to the PP. ConclusionNeurosurgery in the SP and PP is associated with slight reduction in cerebral oxygenation. We speculate that if we rise the lower limit of MAP, we might have showed the beneficial effect of the SP on rSO2.

Long-Term Hearing Outcomes From Gamma Knife Treatment for Vestibulocochlear Nerve Schwannomas in a Large, Tertiary Care, Academic Hospital.

Describe long-term hearing outcomes with audiologic data with modern stereotactic radiosurgery techniques for vestibular schwannoma tumors. Since the mid-20th century, stereotactic radiosurgery has been an option for central nervous system tumors. Due to the non-invasive manner of treatment, this was extended to treatment for benign vestibular schwannomas without intracranial surgery. Modern advances have localized radiation and reduced dosage, but data are still lacking in the long-term hearing outcomes of this method of treatment. As one of the national leaders in this procedure, we present our full database of these outcomes over the full time period of our institutions utility of this modality. A retrospective review was performed of all patients undergoing stereotactic radiotherapy for vestibular schwannomas within the study period of 1998 to 2019 and their audiograms analyzed along with patient data. Laterality Gardner-Robertson hearing score changes were the primary outcome analyzed for each patient; and controls were placed to accommodate for patient demographic data. Long-term, multi-year audiometric evaluation showed statistically significant loss of serviceable hearing and reduction in hearing ability with the use of stereotactic radiosurgery for treatment of vestibular schwannomas. Little long-term data exists on the audiometric outcomes related to stereotactic radiosurgery treatment for vestibular schwannomas. Our institution has performed more than 300 stereotactic radiosurgery treatments showing a continued reduction over time in serviceable hearing. Practitioners should advise patients undergoing treatment for vestibular schwannomas with this treatment of long-term results.

Reasons for not having epilepsy surgery.

This study was undertaken to determine reasons for adults with drug-resistant focal epilepsy who undergo presurgical evaluation not proceeding with surgery, and to identify predictors of this course. We retrospectively analyzed data on 617 consecutive individuals evaluated for epilepsy surgery at a tertiary referral center between January 2015 and December 2019. We compared the characteristics of those in whom a decision not to proceed with surgical treatment was made with those who underwent definitive surgery in the same period. Multivariate logistic regression was performed to identify predictors of not proceeding with surgery. A decision not to proceed with surgery was reached in 315 (51%) of 617 individuals evaluated. Common reasons for this were an inability to localize the epileptogenic zone (n=104) and the presence of multifocal epilepsy (n=74). An individual choice not to proceed with intracranial electroencephalography (icEEG; n=50) or surgery (n=39), risk of significant deficit (n=33), declining noninvasive investigation (n=12), and coexisting neurological comorbidity (n=3) accounted for the remainder. Compared to 166surgically treated patients, those who did not proceed to surgery were more likely to have a learning disability (odds ratio [OR] = 2.35, 95% confidence interval [CI] = 1.07-5.16), normal magnetic resonance imaging (OR = 4.48, 95% CI = 1.68-11.94), extratemporal epilepsy (OR = 2.93, 95% CI = 1.82-4.71), bilateral seizure onset zones (OR = 3.05, 95% CI = 1.41-6.61) and to live in more deprived socioeconomic areas (median deprivation decile = 40%-50% vs. 50%-60%, p<.05). Approximately half of those evaluated for surgical treatment of drug-resistant focal epilepsy do not proceed to surgery. Early consideration and discussion of the likelihood of surgical suitability or need for icEEG may help direct referral for presurgical evaluation.

Nimodipine reduces delayed cerebral vasospasm after intracranial tumour surgery: A Retrospective Study.

Cerebral vasospasm (CVS) is a frequent and serious neurosurgical complication, without sufficient therapy. This retrospective study was performed to analyze if nimodipine can improve prognosis and reduce ischaemia secondary to delayed CVS after intracranial tumour surgery. A retrospective review was performed over the years 2011 to 2012 for patients with an anterior cranial fossa tumour and underwent intracranial tumour surgery. The surgical field was soaked with nimodipine solution or normal saline. Transcranial Doppler ultrasonography was used to measure velocity in the middle cerebral artery (MCA) and the distal extracranial internal carotid artery (eICA). Follow-up was performed using the Glasgow Outcome Scale (GOS) after discharge. There were 94 patients that met the inclusion criteria. They included 50males and 44 females, with a mean age of 49.6years. In the nimodipine group, CVS occurred in 13 patients; 9 patients had CVS between 4 and 7days, and 4had CVS between 8 and 14days. In the normal saline group, 19 patients had CVS, 3 presented with CVS within 3days, 11 between 4-7days and 5 between 8-14days. A significant difference in the occurrence of CVS was observed between the two groups. Preoperative and postoperative the MCA velocities were compared, revealing a significant change in the normal saline group but not in the nimodipine group. Nimodipine markedly improves prognosis and significantly reduces ischaemia secondary to delayed CVS after intracranial tumour surgery, as well as the risks of mortality and morbidity.

Evaluating the role of Smartpilot® view assisted target-controlled infusion anesthesia during intracranial mass surgery: A comparative retrospective study with bispectral index-guided standard anesthesia

Background/Aim: Neuroanesthesia necessitates the control of both systemic and cerebral hemodynamics, the prevention of intracranial pressure increase, knowledge of anesthetics’ cerebral effects, and early neurological recovery. The titration of anesthetics becomes crucial to optimize the appropriate level of anesthesia required for surgery while reducing postoperative neurological consequences. Smartpilot® View (SPV) is a new decision support system that uses pharmacologic models to optimize anesthetic depth and improve patient outcomes. The goal of this study was to compare the effectiveness of SPV with standard BIS-guided anesthesia administration in terms of intraoperative hemodynamic stabilization, anesthetic consumption, and postoperative recovery times during intracranial mass surgery. Methods: Following ethics committee approval, the records of the patients who underwent elective supratentorial craniotomy between November 15, 2017 and March 15, 2018 were reviewed retrospectively. The demographics of the patients, anesthesia and surgery times, eye opening and extubation times, time to reach an Aldrete score of 9 and anesthetic consumptions were compared between those who were monitored with SPV in addition to BIS (SPV Group) and those who were monitored with solely BIS for standard anesthetic follow-up (BIS Group). Results: A total of 139 subjects were analyzed (SPV (n=71), BIS (n=68)). Hemodynamic responses to induction and intubation were more pronounced in the BIS group (P<0.05). Time until eye opening and extubation were 3.6 (2.4) versus 6.06 (1.63) minutes and 5.76 (1.3) versus 9.16 (1.0) minutes in the SPV and BIS groups (P<0.001). In the SPV Group, it took much less time to achieve an Aldrete score of 9 or above (P<0.001). Total consumed amount of both propofol and remifentanil were significantly lower in the SPV group (P<0.001). Conclusion: Use of SPV compared to BIS-guided routine anesthesia follow-up improved titration and consumption of anesthetic drugs, thereby facilitating the early recovery process in patients who underwent intracranial mass surgery.

Comparison of the Safety of Prophylactic Anticoagulants After Intracranial Surgery.

Venous thromboembolism (VTE) represents a rare but preventable postoperative complication. Unfractionated heparin (UH) and low-molecular-weight heparin (LMWH) are used to prevent VTE, but comparative studies of their safety and efficacy in the neurosurgical context are limited. To determine the relative safety and efficacy of UH and LMWH for prophylaxis after cranial surgery. We performed a retrospective analysis of 3204 elective intracranial surgical admissions in 2901 patients over the period 2013 to 2018. From chart review, we extracted demographic and clinical features, including diagnosis and procedure, drugs administered, and the occurrence of VTE events. To compare postoperative outcomes, we performed propensity score matching of patients receiving different drugs, and reviewed postoperative cranial imaging. To contextualize our results, we selected 14 prior neurosurgical studies of VTE prophylaxis to compare our outcomes to the existing literature. In our sample of 3204 admissions, the overall rate of VTE was 0.8% (n=27). Rates of VTE were not statistically different in matched cohorts receiving UH and LMWH (1.7%vs 1.0%, respectively); however, LMWH was associated with a higher rate of clinically significant intracranial hemorrhage (ICH) (3.4%vs 0.5%, P=.008). Literature review and meta-analysis supported these findings. Across studies, UH and LMWH were associated with similar rates of VTE. Studies in which patients received LMWH reported significantly higher rates of ICH (4.9% higher, P=.005). We find that LMWH and UH show similar efficacy in preventing VTE; however, LMWH is associated with higher rates of ICH.

Long-term mood, quality of life, and seizure freedom in intracranial EEG epilepsy surgery

ObjectivesTo determine the long-term outcomes in patients undergoing intracranial EEG (iEEG) evaluation for epilepsy surgery in terms of seizure freedom, mood, and quality of life at St. Vincent’s Hospital, Melbourne. MethodsPatients who underwent iEEG between 1999 and 2016 were identified. Patients were retrospectively assessed between 2014 and 2017 by specialist clinic record review and telephone survey with standardized validated questionnaires for: 1) seizure freedom using the Engel classification; 2) Mood using the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E); 3) Quality-of-life outcomes using the QOLIE-10 questionnaire. Summary statistics and univariate analysis were performed to investigate variables for significance. ResultsSeventy one patients underwent iEEG surgery: 49 Subdural, 14 Depths, 8 Combination with 62/68 (91.9%) of those still alive, available at last follow-up by telephone survey or medical record review (median of 8.2 years). The estimated epileptogenic zone was 62% temporal and 38% extra-temporal. At last follow-up, 69.4% (43/62) were Engel Class I and 30.6% (19/62) were Engel Class II-IV. Further, a depressive episode (NDDI-E > 15)was observed in 34% (16/47), while a ‘better quality of life’ (QOLIE-10 score < 25) was noted in 74% (31/42). Quality of life (p < 0.001) but not mood (p = 0.24) was associated with seizure freedom. SignificanceLong-term seizure freedom can be observed in patients undergoing complex epilepsy surgery with iEEG evaluation and is associated with good quality of life.

Intraoperative lateral rectus electromyographic recordings optimized by deep intraorbital needle electrodes

ObjectiveWe demonstrate the advantages and safety of long, intraorbitally-placed needle electrodes, compared to standard-length subdermal electrodes, when recording lateral rectus electromyography (EMG) during intracranial surgeries. MethodsInsulated 25 mm and uninsulated 13 mm needle electrodes, aimed at the lateral rectus muscle, were placed in parallel during 10 intracranial surgeries, examining spontaneous and stimulation-induced EMG activities. Postoperative complications in these patients were reviewed, alongside additional patients who underwent long electrode placement in the lateral rectus. ResultsIn 40 stimulation-induced recordings from 10 patients, the 25 mm electrodes recorded 6- to 26-fold greater amplitude EMG waveforms than the 13 mm electrodes. The 13 mm electrodes detected greater unwanted volume conduction upon facial nerve stimulation, typically exceeding the amplitude of abducens nerve stimulation. Except for one case with lateral canthus ecchymosis, no clinical or radiographic complications occurred in 36 patients (41 lateral rectus muscles) following needle placement. ConclusionsIntramuscular recordings from long electrode in the lateral rectus offers more reliable EMG monitoring than 13 mm needles, with excellent discrimination between abducens and facial nerve stimulations, and without significant complications from needle placement. SignificanceLong intramuscular electrode within the orbit for lateral rectus EMG recording is practical and reliable for abducens nerve monitoring.

Using Quicktome for Intracerebral Surgery: Early Retrospective Study and Proof of Concept

Neurosurgeons have limited tools in their armamentarium to visualize critical brain networks during surgical planning. Quicktome was designed using machine-learning to generate robust visualization of important brain networks that can be used with standard neuronavigation to minimize those deficits. We sought to see whether Quicktome could help localize important cerebral networks and tracts during intracerebral surgery. We report on all patients who underwent keyhole intracranial surgery with available Quicktome-enabled neuronavigation. We retrospectively analyzed the locations of the lesions and determined functional networks at risks, including chief executive network, default mode network, salience, corticospinal/sensorimotor, language, neglect, and visual networks. We report on the postoperative neurologic outcomes of the patients and retrospectively determined whether the outcomes could be explained by Quicktome's functional localizations. Fifteen high-risk patients underwent craniotomies for intra-axial tumors, with the exception of one meningioma and one case of leukoencephalopathy. Eight patients were male. The median age was 49.6 years. Quicktome was readily integrated in our existing navigation system in every case. New postoperative neurologic deficits occurred in 8 patients. All new deficits, except for one resulting from a postoperative stroke, were expected and could be explained by preoperative findings by Quicktome. In addition, in those who did not have new neurologic deficits, Quicktome offered explanations for their outcomes. Quicktome helps to visualize complex functional connectomic networks and tracts by seamlessly integrating into existing neuronavigation platforms. The added information may assist in reducing neurological deficits and offer explanations for postsurgical outcomes.

Prognostic value of the Simpson grading scale in modern meningioma surgery: Barrow Neurological Institute experience.

Recently, the prognostic value of the Simpson resection grading scale has been called into question for modern meningioma surgery. In this study, the authors analyzed the relationship between Simpson resection grade and meningioma recurrence in their institutional experience. This study is a retrospective review of all patients who underwent resection of a WHO grade I intracranial meningioma at the authors' institution from 2007 to 2017. Binary logistic regression analysis was used to assess for predictors of Simpson grade IV resection and postoperative neurological morbidity. Cox multivariate analysis was used to assess for predictors of tumor recurrence. Kaplan-Meier analysis and log-rank tests were used to assess and compare recurrence-free survival (RFS) of Simpson resection grades, respectively. A total of 492 patients with evaluable data were included for analysis, including 394 women (80.1%) and 98 men (19.9%) with a mean (SD) age of 58.7 (12.8) years. The tumors were most commonly located at the skull base (n = 302; 61.4%) or the convexity/parasagittal region (n = 139; 28.3%). The median (IQR) tumor volume was 6.8 (14.3) cm3. Simpson grade I, II, III, or IV resection was achieved in 105 (21.3%), 155 (31.5%), 52 (10.6%), and 180 (36.6%) patients, respectively. Sixty-three of 180 patients (35.0%) with Simpson grade IV resection were treated with adjuvant radiosurgery. In the multivariate analysis, increasing largest tumor dimension (p < 0.01) and sinus invasion (p < 0.01) predicted Simpson grade IV resection, whereas skull base location predicted neurological morbidity (p = 0.02). Tumor recurrence occurred in 63 patients (12.8%) at a median (IQR) of 36 (40.3) months from surgery. Simpson grade I resection resulted in superior RFS compared with Simpson grade II resection (p = 0.02), Simpson grade III resection (p = 0.01), and Simpson grade IV resection with adjuvant radiosurgery (p = 0.01) or without adjuvant radiosurgery (p < 0.01). In the multivariate analysis, Simpson grade I resection was independently associated with no tumor recurrence (p = 0.04). Simpson grade II and III resections resulted in superior RFS compared with Simpson grade IV resection without adjuvant radiosurgery (p < 0.01) but similar RFS compared with Simpson grade IV resection with adjuvant radiosurgery (p = 0.82). Simpson grade IV resection with adjuvant radiosurgery resulted in superior RFS compared with Simpson grade IV resection without adjuvant radiosurgery (p < 0.01). The Simpson resection grading scale continues to hold substantial prognostic value in the modern neurosurgical era. When feasible, Simpson grade I resection should remain the goal of intracranial meningioma surgery. Simpson grade IV resection with adjuvant radiosurgery resulted in similar RFS compared with Simpson grade II and III resections.

Fulminant Guillain\u2013Barr\xe9 syndrome developed after surgical treatment of intracranial hemorrhage due to arteriovenous malformation: a case report

Guillain–Barré syndrome (GBS) is a rare autoimmune disorder. GBS after surgical treatment of intracranial hemorrhage due to arteriovenous malformation (AVM) is even rarer. We present a 62-year-old man diagnosed with intracranial AVM and cerebral hemorrhage. He developed GBS after the operation for AVM and cerebral hemorrhage. Following surgical excision of AVM and cerebral hematoma, the patient developed generalized weakness, with subsequent quadriplegia and life-threatening dyspnea. The diagnosis was confirmed to be the acute motor–sensory axonal neuropathy subtype of GBS after cerebrospinal fluid analysis and antibody tests. The patient responded poorly to immunoglobulin and steroid therapy. His family abandoned further management and signed out of the hospital against medical advice. Despite being rare, GBS can occur after intracranial hemorrhage and surgery. Clinicians should rule out GBS when patients show no improvement or develop new neurologic