Postoperative Deficits Research Articles

Cortical and subcortical intraoperative-monitoring of the visual pathway under general anesthesia in epilepsy surgery

ObjectiveThe purpose of this study was to evaluate the applicability of visual evoked potentials (VEP) for intraoperative visual pathway monitoring in epilepsy surgery of the posterior hemispheric quadrant (PHQ) and to correlate it with post-operative visual field status. MethodsVEP monitoring was performed in 16 patients (12 females, 7 children). Flash-induced VEP were recorded with strip electrodes from the banks of the calcarine cortex. Latency and amplitude of the first component of VEP (V1-lat, V1-amp) were monitored. Evaluation of the visual field was performed pre- and post-operatively in all patients. ResultsAll procedures were successfully completed without adverse events.In 10 patients the strip covered both the inferior and superior calcarine banks, while only one bank was sampled in 6 cases (inferior in 4, superior in 2). Considering one of the two calcarine banks, at the end of the resection VEP had disappeared in 4 patients, whereas a decrease >33.3% in 4 and <20% of V1-amp was recorded in 5 and in 4 cases respectively. The percentage of V1-amp reduction was significantly higher for the patients who experienced a post-operative visual field reduction (p < 0.001). Post-operative visual field deficits were found in patients presenting a reduction >33.3% of V1-amp. ConclusionsVEP monitoring is possible and safe in epilepsy surgery under general anesthesia. SignificanceIntraoperative recording of VEP from the banks of the calcarine cortex allows monitoring the integrity of post-geniculate visual pathways during PHQ resections for epilepsy and it is pivotal to prevent disabling visual field defects, including hemianopia and inferior quadrantanopia.

Global utilization of biportal spinal endoscopy: Case series on management of lumbar pathology in Soddo, Ethiopia

IntroductionBiportal spinal endoscopy is a safe and cost-effective methodology for the management of lumbar pathology in rural underserved hospitals that have standard orthopaedic arthroscopic equipment, but lack access to microscopy. MethodsThis is a case series noting 1-year outcomes from 5 patients managed with biportal spinal endoscopy during an 11-day mission trip to Soddo, Ethiopia in November 2022. Surgical complications, postoperative assessments, and patient-reported outcomes (PROs) were retrospectively collected and analyzed. Surgical techniques and equipment utilized were shared with residents and faculty at the hospital. ResultsFive Ethiopian patients (4:1, female:male) with no prior spine surgery history elected to undergo biportal surgery for the diagnoses of lumbar stenosis and disc herniation, averaging 31 years of age with Body-Mass-Indices (BMI) <35. Two patients underwent endoscopic discectomy, and three patients underwent endoscopic unilateral laminotomy and bilateral decompression (ULBD). There were no complications. No postoperative functional deficits, infections, readmissions, revisions, or wound dehiscences were noted at 12 months follow-up. VAS-back and VAS-leg scores improved to <2/10 for 80 % of patients. All patients returned to work/activities of daily living. No patients required postoperative pain management beyond the 2-week post-operative follow-up. ConclusionWith these five patients, we found that biportal spinal endoscopy can be safely applied in rural hospital settings with limited resources. This supports biportal spinal endoscopy as a viable minimally invasive modality for the management of lumbar pathology. For hospitals with limited resources, but access to arthroscopic equipment, biportal spinal endoscopy is a feasible option. Level of evidenceIV.

Interventional neurorehabilitation for glioma patients: A systematic review

Abstract Harnessing the neuroplastic potential of the human brain is being increasingly recognized as an important neuro-oncological paradigm to facilitate safe resection of brain tumors while preserving neurological function and quality of life. Interventional neurorehabilitation, employing both invasive and noninvasive neuromodulation techniques, represents an important emerging therapeutic strategy to induce or enhance neural plasticity to promote functional recovery in brain tumor patients. This study aimed to conduct a comprehensive review of interventional neurorehabilitation techniques for glioma patients. Methods: In accordance with PRISMA guidelines, searches of Medline, Embase, Web of Science, APA PsycINFO, and Cochrane were undertaken from database inception to November 28, 2023. Studies reporting on neuromodulation applied to glioma patients were included. Results: Seven studies reporting findings from 118 patients met the inclusion criteria. Three neuromodulation techniques were identified and included transcranial magnetic stimulation (TMS) reported in 5 out of 7 (71.4%) studies; transcranial direct current stimulation (tDCS); and continuous cortical electrical stimulation (cCES) using grid electrodes, reported in one study each. All studies applying noninvasive stimulation to ameliorate postoperative deficits demonstrated an improvement on at least one outcome measure. The 2 studies applying tDCS and cCES to induce plasticity reported evidence of functional reorganization. Conclusions: There is emerging evidence of benefits of neuromodulation to improve postoperative outcome in glioma patients. In the current literature, noninvasive stimulation has shown to have a favorable safety profile. Large-scale, double-blind, sham-controlled trials are warranted to further investigate the effectiveness of these interventions for modulating different cognitive networks in patients undergoing glioma surgery.

Surgical outcomes of trigonal intraventricular meningiomas: a single-centre study.

Trigonal meningiomas are rare intraventricular tumours that present a surgical challenge. There is no consensus on the optimal surgical approach to these lesions, though the transtemporal and transparietal approaches are most frequently employed. We aimed to examine the approach-related morbidity and surgical nuances in treating trigonal meningiomas. This retrospective review assimilated data from 64 trigonal meningiomas operated over 15 years. Details of clinicoradiological presentation, surgical approach and intraoperative impression, pathology and incidence of various postoperative deficits were recorded. In our study, Trigonal meningiomas most frequently presented with headache and visual deterioration. The median volume of tumours was 63.6cc. Thirty-one meningiomas each (48.4%) were WHO Grade 1 and WHO Grade 2, while 2 were WHO Grade 3. The most frequent approach employed was transtemporal (38 patients, 59.4%), followed by transparietal (22 patients, 34.4%). After surgery features of raised ICP and altered mental status resolved in all patients, while contralateral limb weakness resolved in 80%, aphasia in 60%, seizures in 70%, and vision loss in 46.2%. Eighteen patients (28.13%) developed transient postoperative neurological deficits, with one patient (1.5%) developing permanent morbidity. Surgery for IVMs results in rapid improvement of neurological status, though visual outcomes are poorer in patients with low vision prior to surgery, longer duration of complaints and optic atrophy. The new postoperative deficits in some patients tend to improve on follow up. Transtemporal and transparietal approaches may be employed, based on multiple factors like tumour extension, loculation of temporal horn, size of lesion with no significant difference in their safety profile.

National survey on perioperative cognitive dysfunction

BackgroundPerioperative cognitive dysfunction (PCD) is a very prevalent clinical syndrome due to the progressive aging of the surgical population.The aim of our study is to evaluate the clinical practice of Spanish anesthesiologists surveyed regarding this entity. Material and methodsProspective online survey conducted by the Neurosciences Section and distributed by SEDAR. Results544 responses were obtained, with a participation rate of 17%. 54.4% of respondents never make a preoperative assessment of cognitive impairment, only 7.5% always do it. 79.6% lack an intraoperative management protocol for the patient at risk of PCD. In the anesthetic planning, only 23.3% of the patients was kept in mind. Eighty-nine percent considered regional anesthesia with or without sedation preferable to general anesthesia for the prevention of PCD. 88.8% considered benzodiazepines to present a high risk of PCD. 71.7% considered that anesthetic depth monitoring could prevent postoperative cognitive deficit. Routine evaluation of postoperative delirium is low, only 14%. More than 80% recognize that PCD is underdiagnosed. ConclusionsAmong Spanish anesthesiologists surveyed, PCD is still a little known and underappreciated entity. It is necessary to raise awareness of the need to detect risk factors for PCD, as well as postoperative assessment and diagnosis. Therefore, the development of guidelines and protocols and the implementation of continuing education programs in which anesthesiologists should be key members of multidisciplinary teams in charge of perioperative care are suggested.

Resection of meningiomas located in motor eloquent areas – comparative analysis of navigated transcranial magnetic stimulation and conventional neuronavigation

ABSTRACT Background Navigated transcranial magnetic stimulation (nTMS) has been established as a preoperative diagnostic procedure in glioma surgery, increasing the extent of resection and preserving functional outcome. nTMS motor mapping for the resection of motor eloquent meningiomas has not been evaluated in a comparative analysis, yet. Methods We conducted a retrospective matched-pair analysis for tumor location and size in meningioma patients with tumors located over or close to the primary motor cortex. Half of the study population received nTMS motor mapping preoperatively (nTMS-group). The primary endpoint were permanent surgery-related motor deficits. Additional factors associated with new motor deficits were evaluated apart from nTMS. Results 62 patients (mean age 62 ± 15.8 years) were evaluated. 31 patients received preoperative nTMS motor mapping. In this group, motor thresholds (rMT) corresponded with tumor location and preoperative motor status, but could not predict motor outcome. No patient with preoperative intact motor function had a surgery-related permanent deficit in the nTMS group whereas four patients in the non-TMS group with preoperative intact motor status harbored from permanent deficits. 13 patients (21.3%) had a permanent motor deficit postoperatively with no difference between the nTMS and the non-TMS-group. Worsening in motor function was associated with higher patient age (p = 0.01) and contact to the superior sagittal sinus (p = 0.027). Conclusion nTMSmotor mapping did not lead to postoperative preservation in motorfunction. nTMS data corresponded well with the preoperative motorstatus and were associated with postoperative permanent deficits if tumors were located over the motor hotspot according to nTMS.

A Systematic Review &amp; Meta-Analysis on Criteria for Transcranial Motor Evoked Potential for Intraoperative Neuromonitoring during Spine Surgeries

Abstract Background Spine Surgery is the definitive treatment and indication for many traumatic spine illnesses, as well as several pathologies and deformities. Surgery in such a vital organ, formed in its core of the neural pathway that controls the whole of the human body, must be as safe, and least risky as possible, so as to prevent injuries to the neural pathway, or the surrounding vessels, or vital organs. Such great importance of the spine and the spinal cord, has urged surgeons and researchers to create techniques through which spine surgeries are well monitored, and the efficacy and normal physiology is well assessed intraoperatively. Objective to conduct a systematic review and meta-analysis of what has been published of the studies using transcranial motor evoked potential for intraoperative neuromonitoring during spine surgeries. This is for acquiring the best criteria for transcranial motor evoked potential (TcMEP) utilization for intraoperative neuromonitoring, as well as identifying the most accurate alarm point for TcMEP during intraoperative neuromonitoring. Patients and Methods a comprehensive and detailed search of literature was conducted through the Pubmed, Google Scholar, and Research Gate databases including articles related to intraoperative neuromonitoring modalities and transcranial motor evoked potential alarm points and criteria. Searches were performed with a combination of MeSH (medical subject headings). Only Studies published in the English Language with no lower date limit were included. The following search string was used in all databases; (“Intraoperative Neuromonitoring” or “Transcranial Motor Evoked Potential”). Results In a prospective study conducted in 2018, performed on 2867 patients, using a 70 % decrease in amplitude of the TcMEP curve as an alarm point during high-risk spinal surgeries, the number of true positive to false positive cases was found to be 126/234, while the number of true negative cases to false negative cases was found to be 2362/9 cases in total. The study demonstrates the necessity of intraoperative neuromonitoring for high-risk spinal surgery. 136 cases in this study were identified as rescue cases, as intraoperative TcMEP alert occurred and intraoperative maneuverings were done to overcome those alerts, hence hindering occurrence of postoperative neural deficit. Conclusion As regards different TcMEP alarm point values, it has been concluded that an alarm point of 50-60% decrease in amplitude of TcMEP is a more sensitive alarm point, than a higher value alarm point of the same modality. An alarm point of &amp;gt; 70% decrease in amplitude has a much less sensitivity value than lower alarm points, which in turn will result in a lot of missed adverse events, and a higher percentage of false negative values.

Risk predictive score and cord morphology classification for intraoperative neuromonitoring alerts in kyphosis surgery

BACKGROUNDIntraoperative neuromonitoring (IONM) alert is one of the worrying events of kyphosis corrective surgery, which can result in a postoperative neurological deficit. To our knowledge, there is no risk prediction score to predict such events in patients undergoing kyphosis surgery. PURPOSETo develop a new preoperative MRI-based cord morphology classification (CMC) and risk prediction score for predicting IONM alerts in patients with kyphotic deformity. STUDY DESIGNRetrospective analysis of prospectively collected data. PATIENT SAMPLEAbout 114 patients undergoing surgical correction for kyphotic deformity. OUTCOME MEASURESIntraoperative neuromonitoring alerts and postoperative neurological status using AIS grading. METHODSKyphotic deformity patients undergoing posterior spinal fusion were retrospectively reviewed. Based on the morphology of the spinal cord and surrounding CSF in MRI, there are 5 types of cord. Type 1 (normal cord): circular cord with surrounding visible CSF between the cord and the apex, Type 2 (flattened cord): cord with <50% distortion at the apex with obliteration of the anterior CSF; Type 3 (deformed cord): cord with >50% distortion at the apex with complete obliteration of the surrounding CSF; Type 4 (stretched cord): the cord is stretched and atrophied over the apex of the curve. Type 5 (translated cord): horizontal translation of the cord at the apex with buckling collapse of the vertebral column. Preoperative radiographs were used to measure the preoperative sagittal cobbs angle, sagittal deformity angular ratio (S-DAR), sagittal vertical axis (SVA), apex of the curve, and type of kyphosis. Clinical data like the duration of symptoms, clinical signs of myelopathy, neurological status (AIS grade), grade of myelopathy using the mJOA score, and type of osteotomy were documented. Multivariate logistic regression was used to determine the risk factors for IONM alerts and the risk prediction score was developed which was validated with new cohort of 30 patients. RESULTSA total of 114 patients met the inclusion criteria. IONM alerts were documented in 33 patients (28.9%), with full recovery of the signal in 25 patients and a postoperative deficit in 8 patients. Rate of IONM alerts was significantly higher in Type 5 (66%), followed by Type 4 (50%), Type 3 (21.1%), Type 2 (11.1%), and Type 1 (11.1%) (p-value<.001). Based on multiple logistic regression, 7 factors, namely preoperative neurological status, mJOA score≤6, presence of signs of myelopathy, apex of the curve above T5, preoperative sagittal cobbs, S-DAR, and MRI-based CMC, were identified as risk predictors. The value for the risk factors varies from 0 to 4, and the maximum total risk score was 13. The cut-off value of 6 had good sensitivity (84.9%) and specificity (77.8%) indicating a high risk for IONM alerts. The AUC of the predictive model was 0.92, indicating excellent discriminative ability. CONCLUSIONWe developed and validated a risk predictive score that identifies patients at risk of IONM alerts during kyphosis surgery. Identification of such high-risk patients (risk score≥6) helps in proper evaluation and preoperative counselling and helps in providing a proper evidence-based reference for treatment strategies.

Microsurgical anatomy and approaches to thalamic gliomas. Part 2: Maximal safe resection of thalamic gliomas improves outcomes. A single-center experience.

As presented in Part 1 of this series, thalamic gliomas (TGs) are deep-seated, difficult-to-access tumors surrounded by vital neurovascular structures. Given their high operative morbidity, TGs have historically been considered inoperable lesions. Although maximal safe resection (MSR) has become the treatment standard for lobar and even deep-seated mediobasal temporal and insular gliomas, the eloquent location of TGs has precluded this management strategy, with biopsy and adjuvant treatment being the mainstay. The authors hypothesized that MSR can be achieved with low morbidity and mortality for TGs, thus resulting in improved outcomes. A retrospective single-center study was performed on all TG patients from 2006 to 2020. Clinical, imaging, and pathology reports were obtained. Univariate and multivariate analyses were performed to determine prognostic variables. Case examples illustrate various approaches and the rationale for staging resections of more complex TGs. A total of 42 patients (26 males, 16 females), among them 12 pediatric (29%) cases, were included. Their mean age was 36.0 ± 21.4 (median 30, range 3-73) years. The median maximal tumor diameter was 45 (range 19-70) mm. Eighteen patients (43%) had a prior stereotactic needle tumor biopsy, with the ultimate diagnosis changed for 7 patients (39%) following microsurgical resection. The most common surgical approaches were transtemporal (29%), anterior interhemispheric transcallosal (29%), and superior parietal lobule (25%). Overall, the combined subtotal and gross-total resection rate was 95% (n = 40). Low-grade gliomas (LGGs; grades I and II) comprised one-third of the group, whereas half of the patients had glioblastoma multiforme. There were no operative mortalities. Although temporary postoperative motor deficits were observed in 12 patients (28.6%), all improved during the early postoperative period except 1 (2.4%), who had mild residual hemiparesis. Two patients required CSF diversion for hydrocephalus. The 2-year overall survival rate was 90% for LGG patients and 15% for high-grade glioma (HGG) patients. Multivariate analysis revealed that histological grade, age, and extent of resection were independent prognostic factors associated with survival. Management of TGs is challenging, with resection avoided by many, if not most, neurosurgeons, especially for HGGs. The results reported here demonstrate improved outcomes with resection, particularly in younger LGG patients. The authors therefore advocate for MSR for a select cohort of TG patients using carefully planned surgical approaches, contemporary intraoperative adjuncts, and meticulous microsurgical techniques.

Comparison of Different Genioplasty Techniques in Terms of Neurosensory Deficit and Haematoma Formation.

To compare different types of genioplasty techniques (chin advancement, rotation and advancement, setback, and reduction) in terms of neurosensory deficit and haematoma formation. Comparative analytical study. Place and Duration of the Study: Department of Oral and Maxillofacial Surgery, Armed Forces Institute of Dentistry, Rawalpindi, Pakistan, from January 2022 to April 2023. Patients requiring genioplasty and fulfilling the inclusion criteria i.e. both genders aged 16-60 years were included and divided into 4 groups according to the type of genioplasty performed. Genioplasty was planned as per the ortho treatment plan and performed under general anaesthesia. Setback genioplasty was performed on 8 patients, advancement genioplasty on 11 patients, reduction genioplasty on 3, and advancement with rotation genioplasty on 16 patients. Postoperatively neurosensory deficit was recorded on follow-up after 1 month by subjective and objective assessments, and haematoma formation was assessed clinically on the 7th day after the procedure. Advancement with rotation genioplasty showed the highest frequency of neurosensory deficit (almost 50%) and reduction type genioplasty showed the least frequency of neurosensory deficit (<1%, p = 0.49). The frequency of haematoma formation was maximum in the advancement with rotation genioplasty (62.5%) and minimum in equal setback genioplasty (25%, p = 0.61). Advancement with rotation genioplasty had the highest rate of postoperative neurosensory deficit and haematoma formation when compared with other techniques of genioplasty. Genioplasty, Neurosensory deficit, Haematoma, Advancement with rotation genioplasty, Setback genioplasty.

The unseen impact - a deep dive into neurocognitive impairment among patients with intracranial meningiomas: a comprehensive systematic review of the literature.

Meningiomas are the most common intracranial tumors, predominantly affecting adults, with a higher incidence in female and elderly populations. Despite their prevalence, research on neurocognitive impairment in meningioma patients remains limited compared to intra-axial tumors such as gliomas. We conducted a comprehensive systematic review of the current literature on neurocognitive outcomes in meningioma patients pre- and post-surgery. Our review revealed significant disparities in reported neurocognitive outcomes, with prospective studies suggesting tumor-related factors as the primary contributors to postoperative deficits, while retrospective studies imply surgical intervention plays a significant role. Regardless of study design or specifics, most studies lack baseline preoperative neurocognitive assessments and standardized protocols for evaluating neurocognitive function. To address these gaps, we advocate for standardized neurocognitive assessment protocols, consensus on neurocognitive domains to be targeted in this population by tailored test batteries, and more prospective studies to elucidate correlations between tumor characteristics, patient attributes, surgical interventions, neurocognitive status, and planning for implementing tailored neurocognitive rehabilitation strategies early in the postoperative course which is crucial for achieving optimal long-term neurocognitive outcomes and enhancing patients' quality of life.

Long-term Follow-up with MRI Scans After Enucleation of Peripheral Nerve Schwannomas: Results from a Single-center Case Series

BackgroundEnucleation is a surgical technique to resect peripheral nerve schwannomas. The procedure has a low risk for postoperative deficit, but a small chance for recurrence, because tumor cells may remain inside the pseudocapsule that is left after resection. MRI scans are frequently performed after surgery to investigate potential residual tumor, but currently there is little information in the literature on the value of follow-up with MRI. Material and methodsAll patients that underwent enucleation of a peripheral nerve schwannoma between October 2013 and June 2022 were included. Postoperative MRI scans (Gadolinium enhanced) made at different time-points after the surgery were re-examined for residual enhancement. Patients with residual enhancement were contacted to inform whether symptoms had recurred. ResultsA total of 75 schwannoma enucleations in 74 patients were included. The first postoperative MRI scan, performed three months after the surgery, showed no residual enhancement in 50 patients. In the remaining 24 patients, another MRI scan was made one year after the surgery, which still showed a possible remnant in 11 patients. On the third MRI scan, performed two years after enucleation, there were seven suspected cases (9%). None of these patients had clinical symptoms at a mean postoperative follow-up of five years. ConclusionsOur data shows that the value of postoperative MRI scans after enucleation of peripheral nerve schwannomas is limited, because residual enhancement in the beginning can be non-specific and the small percentage of patients, that persistently had a potential remnant, were all asymptomatic.

Improved rates of postoperative ischemia, completeness of aneurysm occlusion and neurological deficits in elective clipping of anterior circulation aneurysms over the past 20 years – association with technical improvements

Background/PurposeSeveral periprocedural adjuncts for elective surgical aneurysm treatment have been introduced over the last 20 years to increase safety and efficacy. Besides the introduction of IONM in the late-1990s, ICG-videoangiography (ICG-VAG) since the mid-2000s and intraoperative CT-angiography/-perfusion (iCT-A/-P) since the mid-2010s are available. We aimed to clarify whether the introduction of ICG-VAG and iCT-A/-P resulted in our department in a stepwise improvement in the rate of radiologically detected postoperative ischemia, complete aneurysm occlusion and postoperative new deficits.MethodsPatients undergoing microsurgical clip occlusion for unruptured anterior circulation aneurysms between 2000 and 2019 were included, with ICG-VAG since 2009 and iCT-A/-P (for selected cases) since 2016. Baseline characteristics and treatment-related morbidity/outcome focusing on differences between the three distinct cohorts (cohort-I: pre-ICG-VAG-era, cohort-II: ICG-VAG-era, cohort-III: ICG-VAG&iCT-A/-P-era) were analyzed.Results1391 patients were enrolled (n = 74 were excluded), 779 patients were interventionally treated, 538 patients were surgically clipped by a specialized vascular team (cohort-I n = 167, cohort-II n = 284, cohort-III n = 87). Aneurysm size was larger in cohort-I (8.9 vs. 7.5/6.8 mm; p < 0.01) without differences concerning age (mean:55years), gender distribution (m: f = 1:2.6) and aneurysm location (MCA:61%, ICA:18%, ACA/AcomA:21%). There was a stepwise improvement in the rate of radiologically detected postoperative ischemia (16.2vs.12.0vs.8.0%; p = 0.161), complete aneurysm occlusion (68.3vs.83.6vs.91.0%; p < 0.01) and postoperative new deficits (10.8vs.7.7vs.5.7%; p = 0.335) from cohort-I to -III. After a mean follow-up of 12months, a median modified Rankin scale of 0 was achieved in all cohorts.DiscussionAssociated with periprocedural technical achievements, surgical outcome in elective anterior circulation aneurysm surgery has improved in our service during the past 20 years.

ACL Reconstruction Using Quadrupled Semitendinosus Versus Double-Stranded Semitendinosus and Gracilis Autograft: 2-Year Results From a Prospective Randomized Controlled Study

Background: A disadvantage of using hamstring tendon autograft consisting of the semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction is pain from tendon harvesting and persistent hamstring weakness. In the tendon-sparing all-inside technique, a quadrupled semitendinosus graft and adjustable-loop cortical fixation are suggested to give less postoperative flexion deficits while displaying overall similar clinical results to the traditional hamstring technique. However, there are a limited number of high-quality studies comparing these techniques with inconsistent results. Purpose: To investigate differences between the all-inside (quadrupled semitendinosus) and traditional hamstring (double-stranded semitendinosus and gracilis) technique regarding (1) self-reported function, (2) hamstring strength, and (3) knee laxity. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 98 patients were randomized to either the all-inside or the traditional hamstring technique. Perioperatively, duration of surgery and graft size were obtained. The International Knee Documentation Committee 2000 Subjective Knee Form score, Knee injury and Osteoarthritis Outcome Score, Tegner Activity Scale score, knee laxity (KT-1000 arthrometer side-to-side difference and pivot shift), range of motion, isokinetic knee strength, and hop test score were collected preoperatively and 2 years postoperatively. Return-to-sport readiness was evaluated 9 months postoperatively. Results: A total of 89 patients completed 2-year follow-up, 45 patients with the all-inside technique and 44 patients with the traditional hamstring technique. There were no significant differences between groups in any of the outcome measures 2 years after surgery, but there was a tendency in the all-inside group toward having increased anterior translation (mean, 3.6 mm vs 2.7 mm), a higher number of revision surgeries (5 patients vs 2 patients), and more patients having +1 and +2 pivot-shift values (29 vs 18 patients) when compared with the traditional group. Conclusion: The all-inside technique yields equivalent results to the traditional hamstring technique 2 years after surgery and should be considered a reliable technique to use for ACL reconstruction. Sparing the gracilis tendon does not lead to less persistent hamstring weakness. Long-term follow-up is needed to further determine whether the tendency of increased anterior translation seen at 2 years postoperatively will lead to a higher risk of graft failure.

Gut Microbiota-Mediated Alterations of Hippocampal CB1R Regulating the Diurnal Variation of Cognitive Impairment Induced by Hepatic Ischemia-Reperfusion Injury in Mice.

Patients suffering from hepatic ischemia-reperfusion injury (HIRI) frequently exhibit postoperative cognitive deficits. Our previous observations have emphasized the diurnal variation in hepatic ischemia-reperfusion injury-induced cognitive impairment, in which gut microbiota-associated hippocampal lipid metabolism plays an important role. Herein, we further investigated the molecular mechanisms involved in the process. Hepatic ischemia-reperfusion surgery was performed under morning (ZT0, 08:00) and evening (ZT12, 20:00). Fecal microbiota transplantation was used to associate HIRI model with pseudo-germ-free mice. The novel object recognition test and Y-maze test were used to assess cognitive function. 16S rRNA gene sequencing and analysis were used for microbial analysis. Western blotting was used for hippocampal protein analysis. Compared with the ZT0-HIRI group, ZT12-HIRI mice showed learning and short term memory impairment, accompanied by down-regulated expression of hippocampal CB1R, but not CB2R. Both gut microbiota composition and microbiota metabolites were significantly different in ZT12-HIRI mice compared with ZT0-HIRI. Fecal microbiota transplantation from the ZT12-HIRI was demonstrated to induce cognitive impairment behavior and down-regulated hippocampal CB1R and β-arrestin1. Intraperitoneal administration of CB1R inhibitor AM251 (1mg/kg) down-regulated hippocampal CB1R and caused cognitive impairment in ZT0-HIRI mice. And intraperitoneal administration of CB1R agonist WIN 55,212-2 (1mg/kg) up-regulated hippocampal CB1R and improved cognitive impairment in ZT12-HIRI mice. In summary, the results suggest that gut microbiota may regulate the diurnal variation of HIRI-induced cognitive function by interfering with hippocampal CB1R.

Factors affecting the extent of resection and neurological outcomes following transopercular resection of insular gliomas

BackgroundSurgical resection of insular gliomas is a challenge. TO resection is considered more versatile and has lower risk of vascular damage. In this study, we aimed to understand the factors that affect resection rates, ischemic changes and neurological outcomes and studied the utility of IONM in patients who underwent TO resection for IGs.MethodsRetrospective analysis of 66 patients with IG who underwent TO resection was performed.ResultsRadical resection was possible in 39% patients. Involvement of zone II and the absence of contrast enhancement predicted lower resection rate. Persistent deficit rate was 10.9%. Although dominant lobe tumors increased immediate deficit and fronto-orbital operculum involvement reduced prolonged deficit rate, no tumor related factor showed significant association with persistent deficits. 45% of patients developed a postoperative infarct, 53% of whom developed deficits. Most affected vascular territory was lenticulostriate (39%). MEP changes were observed in 9/57 patients. 67% of stable TcMEPs and 74.5% of stable strip MEPs did not develop any postoperative motor deficits. Long-term deficits were seen in 3 and 6% patients with stable TcMEP and strip MEPs respectively. In contrast, 25% and 50% of patients with reversible strip MEP and Tc MEP changes respectively had persistent motor deficits. DWI changes were clinically more relevant when accompanied by MEP changes intraoperatively, with persistent deficit rates three times greater when MEP changes occurred than when MEPs were stable.ConclusionRadical resection can be achieved in large, multizone IGs, with reasonable outcomes using TO approach and multimodal intraoperative strategy with IONM.

P.088 Wounded glioma syndrome: neurologic worsening in patients with subtotal resection in high-grade gliomas

Background: For treatment of high-grade gliomas (HGGs), subtotal resection (STR) may be preferred to minimize injury to eloquent areas. We aimed to characterize neurologic deficits developed in STR patients within the first month post-operatively and to establish a potential threshold for a safe volume of residual tumor to avoid neurological worsening. Methods: This is a single institution retrospective chart review, with 146 charts reviewed and 78 patients deemed eligible. Preoperative deficits and postoperative neurological deficits presenting prior to 1 month after surgery were captured. Imaging features such as tumour volume, edema, and other pertinent imaging characteristics were collected from preoperative and postoperative imaging. Results: Most patients that developed a postoperative deficit presented with motor deficits (55.1%), while only 1.3% of patients developed new or worsening tremor after surgery. On average, in patients with a new deficit, 26.5% of tumor was resected, and all patients had more than 19% of residual tumor. Conclusions: Postoperative neurologic deficits may develop after a subtotal resection when an average of 73.5% of tumor remains. The proposed threshold for tumor resection is greater than 26.5% to minimize the potential of neurologic worsening 1 month postoperatively.

A critical event frequent lead to reversible spinal cord injury during vertebral column resection surgery.

To report a "critical phase" (between osteotomy completion and correction beginning) that will frequently lead to the reversible intraoperative neurophysiological monitoring (IOM) change during posterior vertebral column resection (PVCR) surgery. The study sample consisted of 120 patients with severe spine deformity who underwent PVCR and deformity correction surgeries. Those patients were recruited consecutively from 2010 to 2018 January in our spine center. The detailed IOM data (the amplitude of MEP & SEP) and its corresponding surgical points were collected prospectively. Early and long-term postoperative neurologic outcomes were assessed for the following functions: motor, sensory, and pain at immediate postoperative and 1-year post-operation in this cases series. A total of 105 (105/120) patients presented varying degrees of IOM reduction in the critical phase; the mean IOM amplitude retention vs rescue rate was 27% ± 11.2 versus 58% ± 16.9, P < 0.01 (MEP) & 34% ± 8.3 versus 66% ± 12.4 P < 0.01 (SEP). Patients with postoperative spinal deficits often had a significantly longer IOM-alerting duration than the patients without (p < 0.01, Mann-Whitney U-test), and IOM-alerting duration greater than 39.5min was identified as an independent predictor of the risk of postoperative spinal deficits. The reversible IOM events probably often appear in the critical phase during PVCR surgery. The new postoperative spinal deficits are possible for patients without satisfied IOM recovery or alerting duration greater than 39.5min. Timely and suitable surgical interventions are useful for rescuing the IOM alerts.

Schwannoma of Ansa-Cervicalis: A Rare Location for Schwannoma.

Schwannomas are rare neoplasms that originate from the nervous system. We describe a case of schwannoma of the ansa-cervicalis in a patient where preoperative imaging is suggestive of glomus caroticum tumor. A 44-year-old man presented to the surgical oncology department with a recurrent anterior triangle neck swelling. Magnatic resonance ımaging (MRI) demonstrated right enhancing soft tissue mass at the carotid bifurcation consistent with glomus tumor. Intraoperatively, the lesion was found abuting the bifurcatuion and arising from the right ansa-cervicalis. Histopathology evaluation revealed schwannoma. Schwannoma of the ansa-cervicalis is extremely rare. Very few cases have been reported in the literature. Making the preoperative diagnosis is difficult. Preoperative imaging is necessary to rule out other causes of neck masses such as thyroid lesions, lymphadenopathy, and carotid body tumor. Verocay bodies were noted on histology. Schwannoma of cervical region can have origin from any nerve. Any Neurologic post-operative deficit depends on the nerve of origin and the precision of the surgery performed.

Bayesian networks for Risk Assessment and postoperative deficit prediction in intraoperative neurophysiology for brain surgery.

To this day there is no consensus regarding evidence of usefulness of Intraoperative Neurophysiological Monitoring (IONM). Randomized controlled trials have not been performed in the past mainly because of difficulties in recruitment control subjects. In this study, we propose the use of Bayesian Networks to assess evidence in IONM. Single center retrospective study from January 2020 to January 2022. Patients admitted for cranial neurosurgery with intraoperative neuromonitoring were enrolled. We built a Bayesian Network with utility calculation using expert domain knowledge based on logistic regression as potential causal inference between events in surgery that could lead to central nervous system injury and postoperative neurological function. A total of 267 patients were included in the study: 198 (73.9%) underwent neuro-oncology surgery and 69 (26.1%) neurovascular surgery. 50.7% of patients were female while 49.3% were male. Using the Bayesian Network´s original state probabilities, we found that among patients who presented with a reversible signal change that was acted upon, 59% of patients would wake up with no new neurological deficits, 33% with a transitory deficit and 8% with a permanent deficit. If the signal change was permanent, in 16% of the patients the deficit would be transitory and in 51% it would be permanent. 33% of patients would wake up with no new postoperative deficit. Our network also shows that utility increases when corrective actions are taken to revert a signal change. Bayesian Networks are an effective way to audit clinical practice within IONM. We have found that IONM warnings can serve to prevent neurological deficits in patients, especially when corrective surgical action is taken to attempt to revert signals changes back to baseline properties. We show that Bayesian Networks could be used as a mathematical tool to calculate the utility of conducting IONM, which could save costs in healthcare when performed.