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Ian Masse, Luc Moquin, Caroline Bouchard, Alain Gratton, and Louis De Beaumont

OBJECTIVE

Alterations in amino acid concentrations are a major contributor to the persistent neurological and behavioral effects induced by concussions and mild traumatic brain injuries (TBIs). Glutamate, the most abundant excitatory amino acid in the CNS, has a major role in the pathophysiological process of concussion. The indiscriminate liberation of glutamate immediately after a concussion triggers an excitotoxic response that leads to cell death, neuronal damage, and the dysfunction of surviving neurons, largely by overactivation of N-methyl-d-aspartate (NMDA) glutamatergic receptors. The aim of the present study was to investigate the efficacy of prophylactic versus therapeutic administration of MK-801, a promising NMDA receptor antagonist, on the acute changes in amino acid extracellular concentrations involved in excitotoxicity resulting from a concussive trauma.

METHODS

The immediate neurochemical response to a concussion cannot be characterized in humans. Therefore, the authors used their previously validated combination of a weight-drop concussion rat model and in vivo cerebral microdialysis. The microdialysis probe was inserted inside the hippocampus and left inserted at impact to allow uninterrupted sampling of amino acids of interest immediately after concussion. The primary outcome included amino acid concentrations and the secondary outcome included righting time. Samples were taken in 10-minute increments for 60 minutes before, during, and 60 minutes after impact, and analyzed for glutamate, gamma-aminobutyric acid, taurine, glycine, glutamine, and serine using high-performance liquid chromatography. Righting time was acquired as a neurological restoration indicator. Physiological saline or 10 mg/kg MK-801 was administrated intraperitoneally 60 minutes before or immediately following induction of sham injury or concussion.

RESULTS

Following induction of concussion, glutamate, taurine, and glycine levels as well as righting times in cases from the MK-801 treatment group were comparable to those of vehicle-treated animals. In contrast, righting times and amino acid concentrations observed within the first 10 minutes after induction of concussion in cases assigned to the MK-801 prophylaxis group were comparable to those of sham-injured animals.

CONCLUSIONS

These results suggest that presynaptic actions and peak availability of MK-801 following prophylactic administration significantly inhibit the immediate and indiscriminate release of glutamate, taurine, and glycine in extracellular fluid after a concussion.

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Siyuan Yu, Mohammad Taghvaei, Sarah Collopy, Keenan Piper, Michael Karsy, Pascal Lavergne, Blair Barton, Chandala Chitguppi, Glen D’Souza, Marc R. Rosen, Gurston G. Nyquist, Mindy Rabinowitz, Christopher J. Farrell, and James J. Evans

OBJECTIVE

While multiple studies have evaluated the length of stay after endonasal transsphenoidal surgery (ETS) for pituitary adenoma, the potential for early discharge on postoperative day 1 (POD 1) remains unclear. The authors compared patients discharged on POD 1 with patients discharged on POD > 1 to better characterize factors that facilitate early discharge after ETS.

METHODS

A retrospective chart review was performed for patients undergoing ETS for pituitary adenoma at a single tertiary care academic center from February 2005 to February 2020. Discharge on POD 1 was defined as a discharge within 24 hours of surgery.

RESULTS

A total of 726 patients (mean age 55 years, 52% male) were identified, of whom 178 (24.5%) patients were discharged on POD 1. These patients were more likely to have pituitary incidentaloma (p = 0.001), require dural substitutes and DuraSeal (p = 0.0001), have fewer intraoperative CSF leaks (p = 0.02), and have lower postoperative complication rates (p = 0.006) compared with patients discharged on POD > 1. POD 1 patients also showed higher rates of macroadenomas (96.1% vs 91.4%, p = 0.03) and lower rates of functional tumors (p = 0.02). POD > 1 patients were more likely to have readmission within 30 days (p = 0.002), readmission after 30 days (p = 0.0001), nasal synechiae on follow-up (p = 0.003), diabetes insipidus (DI; 1.7% vs 9.8%, p = 0.0001), postoperative hypocortisolism (21.8% vs 12.1%, p = 0.01), and postoperative steroid usage (44.6% vs 59.7%, p = 0.003). The number of patients discharged on POD 1 significantly increased during each subsequent time epoch: 2005–2010, 2011–2015, and 2016–2020 (p = 0.0001). On multivariate analysis, DI (OR 7.02, 95% CI 2.01–24.57; p = 0.002) and intraoperative leak (OR 2.02, 95% CI 1.25–3.28; p = 0.004) were associated with increased risk for POD > 1 discharge, while operation epoch (OR 0.46, 95% CI 0.3–0.71; p = 0.0001) was associated with POD 1 discharge.

CONCLUSIONS

This study demonstrates that discharge on POD 1 after ETS for pituitary adenomas was safe and feasible and without increased risk of 30-day readmission. On multivariate analysis, surgical epoch was associated with decreased risk of prolonged length of stay, while factors associated with increased risk of prolonged length of stay included DI and intraoperative CSF leak. These findings may help in selecting patients who are deemed reasonable for safe, early discharge after pituitary adenoma resection.

Open access

Faith C. Robertson, Raahil M. Sha, Jose M. Amich, Walid Ibn Essayed, Avinash Lal, Benjamin H. Lee, Paola Calvachi Prieto, Junichi Tokuda, James C. Weaver, Ramez W. Kirollos, Min Wei Chen, and William B. Gormley

OBJECTIVE

A major obstacle to improving bedside neurosurgical procedure safety and accuracy with image guidance technologies is the lack of a rapidly deployable, real-time registration and tracking system for a moving patient. This deficiency explains the persistence of freehand placement of external ventricular drains, which has an inherent risk of inaccurate positioning, multiple passes, tract hemorrhage, and injury to adjacent brain parenchyma. Here, the authors introduce and validate a novel image registration and real-time tracking system for frameless stereotactic neuronavigation and catheter placement in the nonimmobilized patient.

METHODS

Computer vision technology was used to develop an algorithm that performed near-continuous, automatic, and marker-less image registration. The program fuses a subject’s preprocedure CT scans to live 3D camera images (Snap-Surface), and patient movement is incorporated by artificial intelligence–driven recalibration (Real-Track). The surface registration error (SRE) and target registration error (TRE) were calculated for 5 cadaveric heads that underwent serial movements (fast and slow velocity roll, pitch, and yaw motions) and several test conditions, such as surgical draping with limited anatomical exposure and differential subject lighting. Six catheters were placed in each cadaveric head (30 total placements) with a simulated sterile technique. Postprocedure CT scans allowed comparison of planned and actual catheter positions for user error calculation.

RESULTS

Registration was successful for all 5 cadaveric specimens, with an overall mean (± standard deviation) SRE of 0.429 ± 0.108 mm for the catheter placements. Accuracy of TRE was maintained under 1.2 mm throughout specimen movements of low and high velocities of roll, pitch, and yaw, with the slowest recalibration time of 0.23 seconds. There were no statistically significant differences in SRE when the specimens were draped or fully undraped (p = 0.336). Performing registration in a bright versus a dimly lit environment had no statistically significant effect on SRE (p = 0.742 and 0.859, respectively). For the catheter placements, mean TRE was 0.862 ± 0.322 mm and mean user error (difference between target and actual catheter tip) was 1.674 ± 1.195 mm.

CONCLUSIONS

This computer vision–based registration system provided real-time tracking of cadaveric heads with a recalibration time of less than one-quarter of a second with submillimetric accuracy and enabled catheter placements with millimetric accuracy. Using this approach to guide bedside ventriculostomy could reduce complications, improve safety, and be extrapolated to other frameless stereotactic applications in awake, nonimmobilized patients.

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Massimo Cossu, Michele Nichelatti, Alessandro De Benedictis, and Michele Rizzi

OBJECTIVE

Lateral periinsular hemispherotomy (LPH) and vertical parasagittal hemispherotomy (VPH) are the most popular disconnective techniques for intractable epilepsies associated with unilateral hemispheric pathologies. The authors aimed to investigate possible differences in seizure outcome and complication rates between patients who underwent LPH and VPH.

METHODS

A comprehensive literature search of PubMed and Embase identified English-language articles published from database inception to December 2019 that reported series (minimum 12 patients with follow-up ≥ 12 months) on either LPH or VPH. Pooled rates of seizure freedom and complications (with a particular focus on hydrocephalus) were analyzed using meta-analysis to calculate both fixed and random effects. Heterogeneity (Cochran’s Q test) and inconsistency (fraction of Q due to actual heterogeneity) were also calculated.

RESULTS

Twenty-five studies were included. Data from 825 patients were available for seizure outcome analysis (583 underwent LPH and 242 underwent VPH), and data from 692 patients were available for complication analysis (453 underwent LPH and 239 underwent VPH). No differences were found in the pooled rates of Engel class I seizure outcome between patients who underwent LPH (80.02% and 79.44% with fixed and random effects, respectively) and VPH (79.89% and 80.69% with fixed and random effects, respectively) (p = 0.953). No differences were observed in the pooled rates of shunted hydrocephalus between patients who underwent LPH (11.34% and 10.63% with fixed and random effects, respectively) and VPH (11.07% and 9.98% with fixed and random effects, respectively) (p = 0.898). Significant heterogeneity and moderate inconsistency were determined for hydrocephalus occurrence in patients who underwent both LPH and VPH.

CONCLUSIONS

LPH and VPH techniques present similar excellent seizure outcomes, with comparable and acceptable safety profiles.

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Kuntal Kanti Das, Jaskaran Singh Gosal, Deepak Khatri, and Arun K. Srivastava

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Chidinma M. Wilson, Evalyn S. Mackenzie, Mikhal A. Yudien, Antoinette J. Charles, Marianne I. J. Tissot, Sydney J. Churchill, Nolan J. Brown, Jared M. Shulkin, Donald K. E. Detchou, Vamsi P. Reddy, and Lola B. Chambless

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Hirotaka Hasegawa, Kunal Vakharia, Lucas P. Carlstrom, Jamie J. Van Gompel, Colin L. W. Driscoll, Matthew L. Carlson, Fredric B. Meyer, and Michael J. Link

OBJECTIVE

The authors’ objective was to reevaluate the role of microsurgery for epidermoid tumors by examining the associations between extent of resection (EOR), tumor control, and clinical outcomes.

METHODS

This was a retrospective study of patients with microsurgically treated intracranial epidermoid tumors. The recurrence-free and intervention-free rates were calculated using the Kaplan-Meier method. EOR was graded as gross-total resection (GTR) (total resection without residual on MRI), near-total resection (NTR) (a cyst lining was left in place), subtotal resection (STR) (> 90% resection), and partial resection (PR) (any other suboptimal resection) and used to stratify outcomes.

RESULTS

Sixty-three patients with mean clinical and radiological follow-up periods of 87.3 and 81.8 months, respectively, were included. Sixteen patients underwent second resections, and 5 underwent third resections. The rates of GTR/NTR, STR, and PR were 43%, 35%, and 22%, respectively, for the initial resections; 44%, 13%, and 44% for the second resections; and 40%, 0%, and 60% for the third resections (p < 0.001). The 5- and 10-year cumulative recurrence-free rates after initial resection were 64% and 32%, respectively. When stratified according to EOR, the 10-year recurrence-free rate after GTR/NTR was marginally better than that after STR (61% vs 35%, p = 0.130) and significantly better than that after PR (61% vs 0%, p < 0.001). The recurrence-free rates after initial microsurgery were marginally better than those after second surgery (p = 0.102) and third surgery (p = 0.065). The 5- and 10-year cumulative intervention-free rates after initial resection were 91% and 58%, respectively. When stratified according to EOR, the 10-year intervention-free rate after GTR/NTR was significantly better than that after STR (100% vs 51%, p = 0.022) and PR (100% vs 27%, p < 0.001). The 5-year intervention-free rate after initial surgery was marginally better than that after second surgery (52%, p = 0.088) and significantly better than that after third surgery (0%, p = 0.004). After initial, second, and third resections, permanent neurological complications were observed in 6 (10%), 1 (6%), and 1 (20%) patients, respectively. At the last follow-up visit, 82%, 23%, and 7% of patients were free from radiological recurrence after GTR/NTR, STR, and PR as the initial surgical procedure, respectively.

CONCLUSIONS

GTR/NTR seems to contribute to better disease control without significantly impairing functional status. Initial resection offers the best chance to achieve better EOR, leading to better disease control.

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Saniya S. Godil, Umberto Tosi, Mina Gerges, Andrew L. A. Garton, Georgiana A. Dobri, Ashutosh Kacker, Abtin Tabaee, Vijay K. Anand, and Theodore H. Schwartz

OBJECTIVE

Surgical management of craniopharyngiomas (CPAs) is challenging. Controversy exists regarding the optimal goals of surgery. The purpose of this study was to compare the long-term outcomes of patients who underwent gross-total resection with the outcomes of those who underwent subtotal resection of their CPA via an endoscopic endonasal approach.

METHODS

From a prospectively maintained database of all endoscopic endonasal approaches performed at Weill Cornell Medicine, only patients with CPAs with > 3 years of follow-up after surgery were included. The primary endpoint was radiographic progression. Data were collected on baseline demographics, imaging, endocrine function, visual function, and extent of resection.

RESULTS

A total of 44 patients with a mean follow-up of 5.7 ± 2.6 years were included. Of these patients, 14 (31.8%) had prior surgery. GTR was achieved in 77.3% (34/44) of all patients and 89.5% (34/38) of patients in whom it was the goal of surgery. Preoperative tumor volume < 10 cm3 was highly predictive of GTR (p < 0.001). Radiation therapy was administered within the first 3 months after surgery in 1 (2.9%) of 34 patients with GTR and 7 (70%) of 10 patients with STR (p < 0.001). The 5-year recurrence-free/progression-free survival rate was 75.0% after GTR and 25.0% after STR (45% in subgroup with STR plus radiotherapy; p < 0.001). The time to recurrence after GTR was 30.2 months versus 13 months after STR (5.8 months in subgroup with STR plus radiotherapy; p < 0.001). Patients with GTR had a lower rate of visual deterioration and higher rate of return to work or school compared with those with STR (p = 0.02). Patients with GTR compared to STR had a lower rate of CSF leakage (0.0% vs 30%, p = 0.001) but a higher rate of diabetes insipidus (85.3% vs 50%, p = 0.02).

CONCLUSIONS

GTR, which is possible to achieve in smaller tumors, resulted in improved tumor control, better visual outcome, and better functional recovery but a higher rate of diabetes insipidus compared with STR, even when the latter was supplemented with postoperative radiation therapy. GTR should be the goal of craniopharyngioma surgery, when achievable with minimal morbidity.

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Hideaki Nakajima, Kazuya Honjoh, Shuji Watanabe, Arisa Kubota, and Akihiko Matsumine

OBJECTIVE

The development of diffuse idiopathic skeletal hyperostosis (DISH) often requires further surgery after posterior decompression without fusion because of postoperative intervertebral instability. However, there is no information on whether fusion surgery is recommended for these patients as the standard surgery. The aim of this study was to review the clinical and imaging findings in lumbar spinal canal stenosis (LSS) patients with DISH affecting the lumbar segment (L-DISH) and to assess the indication for fusion surgery in patients with DISH.

METHODS

A total of 237 patients with LSS underwent 1- or 2-level posterior lumbar interbody fusion (PLIF) at the authors’ hospital and had a minimum follow-up period of 2 years. Patients with L-DISH were classified as such (n = 27, 11.4%), whereas those without were classified as controls (non-L-DISH; n = 210, 88.6%). The success rates of short-level PLIF were compared in patients with and those without L-DISH. The rates of adjacent segment disease (ASD), pseudarthrosis, postoperative symptoms, and revision surgery were examined in the two groups.

RESULTS

L-DISH from L2 to L4 correlated significantly with early-onset ASD, pseudarthrosis, and the appearance of postsurgical symptoms, especially at a lower segment and one distance from the segment adjacent to L-DISH, which were associated with the worst clinical outcome. Significantly higher percentages of L-DISH patients developed ASD and pseudarthrosis than those in the non-L-DISH group (40.7% vs 4.8% and 29.6% vs 2.4%, respectively). Of those patients with ASD and/or pseudarthrosis, 69.2% were symptomatic and 11.1% underwent revision surgery.

CONCLUSIONS

The results highlighted the negative impact of short-level PLIF surgery for patients with L-DISH. Increased mechanical stress below the fused segment was considered the reason for the poor clinical outcome.