Immunohistochemical markers predicting long-term recurrence following clival and spinal chordoma resection: a multicenter study

OBJECTIVE

Chordomas are rare tumors from notochordal remnants and account for 1%-4% of all primary bone malignancies, often arising from the clivus and sacrum. Despite margin-negative resection and postoperative radiotherapy, chordomas often recur. Further, immunohistochemical (IHC) markers have not been assessed as predictive of chordoma recurrence. The authors aimed to identify the IHC markers that are predictive of postoperative long-term (≥ 1 year) chordoma recurrence by using trained multiple tree-based machine learning (ML) algorithms.

METHODS

The authors reviewed the records of patients who had undergone treatment for clival and spinal chordomas between January 2017 and June 2021 across the Mayo Clinic enterprise (Minnesota, Florida, and Arizona). Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient record. Decision tree and random forest classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split.

RESULTS

One hundred fifty-one patients diagnosed and treated for chordomas were identified: 58 chordomas of the clivus, 48 chordomas of the mobile spine, and 45 chordomas sacrococcygeal in origin. Patients diagnosed with cervical chordomas were the oldest among all groups (58 ± 14 years, p = 0.009). Most patients were male (n = 91, 60.3%) and White (n = 139, 92.1%). Most patients underwent resection with or without radiation therapy (n = 129, 85.4%). Subtotal resection followed by radiation therapy (n = 51, 33.8%) was the most common treatment modality, followed by gross-total resection then radiation therapy (n = 43, 28.5%). Multivariate analysis showed that S100 and pan-cytokeratin are more likely to predict the increase in the risk of postoperative recurrence (OR 3.67, 95% CI 1.09-12.42, p= 0.03; and OR 3.74, 95% CI 0.05-2.21, p = 0.02, respectively). In the decision tree analysis, a clinical follow-up > 1897 days was found in 37% of encounters and a 90% chance of being classified for recurrence (accuracy = 77%). Random forest analysis (n = 500 trees) showed that patient age, type of surgical treatment, location of tumor, S100, pan-cytokeratin, and EMA are the factors predicting long-term recurrence.

CONCLUSIONS

The IHC and clinicopathological variables combined with tree-based ML tools successfully demonstrated a high capacity to identify recurrence patterns with an accuracy of 77%. S100, pan-cytokeratin, and EMA were the IHC drivers of recurrence. This shows the power of ML algorithms in analyzing and predicting outcomes of rare conditions of a small sample size.

Evaluation of Long-Term Follow-Up in Ecchordosis Physaliphora versus Chordoma

OBJECTIVE

Ecchordosis physaliphora (EP) is a non-neoplastic notochord remnant with limited literature. We present a review on surgically resected clival EP to evaluate if available follow-up is adequate to distinguish EP from chordomas.

METHODS

A systematic literature review was completed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Case reports or series of adults with histopathologic and radiographic findings of surgically resected EP were included. Articles including pediatric patients, systematic reviews, chordomas, and without microscopic or radiographic confirmation, or the surgical approach, were excluded. Corresponding authors were contacted twice to further evaluate outcomes.

RESULTS

Eighteen articles were included (n = 25 patients; mean age 47.5 years ± 12.6 [standard deviation] months). All patients had symptomatic, surgically resected EP, with cerebrospinal fluid leak or rhinorrhea the most common symptom (48%). All but 3 had gross total resection, with endoscopic endonasal transsphenoidal transclival the most common approach (80%). All but 3 reported immunohistochemistry findings, with physaliphorous cells the most common. All but 5 patients had definitive follow-up (80%), with average of 19.5 ± 17.2 months. One corresponding author reported longer-term follow-up for 1 patient (57 months). No recurrence or malignant transformation was reported. Mean time to clival chordoma recurrence (53.9 ± 26.8 months) was also evaluated in a review of 8 studies.

CONCLUSIONS

Mean follow-up for resected EP was almost 3 times shorter than mean time to recurrence of chordomas. Available literature is likely inadequate to confirm the suspected benign nature of EP especially in reference to chordoma, precluding treatment and follow-up recommendations.

Stereo-EEG localization of midline onset seizures on scalp EEG

PURPOSE

The objective of this study was to describe the sEEG-defined seizure onset zone (SOZ), seizure semiology, presurgical evaluations, surgical intervention and outcome in patients with midline onset noninvasive phase I monitoring.

METHODS

A single center sEEG database was reviewed to identify patients with seizures onset predominantly involving midline electrodes (FZ, CZ, PZ, OZ) on scalp EEG. Data abstracted included clinical factors, seizure semiology graded into lobar segmentation, imaging and electrographic findings, sEEG plan, interventions, and outcome.

RESULTS

Twelve patients were identified (8 males, median age of sEEG 28 years) out of 100 cases of sEEG performed from January 2015-September 2019. "Frontal lobe" seizure semiology was the most common. sEEG-defined SOZ were frontal (5), diffuse (1), multifocal (1), frontal and insular (1), frontal and cingulate (1), insular (1), cingulate (1), and mesial temporal (1). CZ and/or FZ scalp EEG changes were present for all patients with SOZ involving the frontal, cingulate, and insular regions. PZ/OZ scalp involvement was present in one patient with mesial temporal SOZ. Four patients underwent a definitive resective or ablative surgery, and the remaining patients underwent a palliative intervention. Of those with follow-up information available, 8/11 had seizure reduction by ≥ 50%, including 4 with an Engel I outcome. No clinical factors were associated with outcome.

CONCLUSIONS

SOZ for midline onset seizures from noninvasive phase I monitoring was most commonly in the frontal, cingulate, and insular regions. A complex cortical network between these regions may explain overlap in semiology and scalp EEG findings. While the number rendered seizure-free was limited, a significant proportion experienced a reasonably favorable outcome justifying use of sEEG to identify surgical options in these patients.

A phase 1 open-label trial evaluating focused ultrasound unilateral anterior thalamotomy for focal onset epilepsy

OBJECTIVE

Focused ultrasound ablation (FUSA) is an emerging treatment for neurological and psychiatric diseases. We describe the initial experience from a pilot, open-label, single-center clinical trial of unilateral anterior nucleus of the thalamus (ANT) FUSA in patients with treatment-refractory epilepsy.

METHODS

Two adult subjects with treatment-refractory, focal onset epilepsy were recruited. The subjects received ANT FUSA using the Exablate Neuro (Insightec) system. We determined the safety and feasibility (primary outcomes), and changes in seizure frequency (secondary outcome) at 3, 6, and 12 months. Safety was assessed by the absence of side effects, that is, new onset neurological deficits or performance deterioration on neuropsychological testing. Feasibility was defined as the ability to create a lesion within the anterior nucleus. The monthly seizure frequency was compared between baseline and postthalamotomy.

RESULTS

The patients tolerated the procedure well, without neurological deficits or serious adverse events. One patient experienced a decline in verbal fluency, attention/working memory, and immediate verbal memory. Seizure frequency reduced significantly in both patients; one patient was seizure-free at 12 months, and in the second patient, the frequency reduced from 90-100 seizures per month to 3-6 seizures per month.

SIGNIFICANCE

This is the first known clinical trial to assess the safety, feasibility, and preliminary efficacy of ANT FUSA in adult patients with treatment-refractory focal onset epilepsy.

Predictive Value of K i -67 Index in Evaluating Sporadic Vestibular Schwannoma Recurrence: Systematic Review and Meta-analysis

Introduction  K _i -67 is often used as a proliferation index to evaluate how aggressive a tumor is and its likelihood of recurrence. Vestibular schwannomas (VS) are a unique benign pathology that lends itself well to evaluation with K _i -67 as a potential marker for disease recurrence or progression following surgical resection. Methods  All English language studies of VSs and K _i -67 indices were screened. Studies were considered eligible for inclusion if they reported series of VSs undergoing primary resection without prior irradiation, with outcomes including both recurrence/progression and K _i -67 for individual patients. For published studies reporting pooled K _i -67 index data without detailed by-patient values, we contacted the authors to request data sharing for the current meta-analysis. Studies reporting a relationship between K _i -67 index and clinical outcomes in VS for which detailed patients' outcomes or K _i -67 indices could not be obtained were incorporated into the descriptive analysis, but excluded from the formal (i.e., quantitative) meta-analysis. Results  A systematic review identified 104 candidate citations of which 12 met inclusion criteria. Six of these studies had accessible patient-specific data. Individual patient data were collected from these studies for calculation of discrete study effect sizes, pooling via random-effects modeling with restricted maximum likelihood, and meta-analysis. The standardized mean difference in K _i -67 indices between those with and without recurrence was calculated as 0.79% (95% confidence interval [CI]: 0.28-1.30; p  = 0.0026). Conclusion  K _i -67 index may be higher in VSs that demonstrate recurrence/progression following surgical resection. This may represent a promising means of evaluating tumor recurrence and potential need for early adjuvant therapy for VSs.

Middle Meningeal Artery Aneurysm in a Giant Meningioma

Nontraumatic perilesional aneurysms are thought to occur because of high-flow demands of feeding arteries and neoangiogenesis of hypervascular lesions, most commonly in vascular malformations, but they can rarely be associated with tumors as well. Most of these perilesional aneurysms are from intracranial vasculature associated with branches off the internal carotid artery. We report the unique case of a middle meningeal artery aneurysm associated with a giant convexity meningioma seen on a preoperative angiogram.

Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience

BACKGROUND

Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports.

OBJECTIVE

To report a multicenter experience assessing microsurgery safety/efficacy.

METHODS

Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021).

RESULTS

Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%.

CONCLUSION

Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

Cochlear Implantation After Intralabyrinthine Schwannoma Microsurgical Resection

ABSTRACT

Cochlear implantation after microsurgical resection of intralabyrinthine schwannomas has shown promising results in a limited number of small studies with safe and favorable outcomes. Cochlear implantation is a mainstream treatment for advanced bilateral sensorineural hearing loss and, more recently, has been applied to patients with single-sided deafness.The case presented is a 66-year-old gentleman with a history of progressive right-sided sensorineural hearing loss and bothersome tinnitus with a right intralabyrinthine schwannoma involving the semicircular canals, vestibule, and basal turn of the cochlea. The authors describe concomitant cochlear implantation after microsurgical resection of an intralabyrinthine schwannoma. Intralabyrinthine schwannomas represent an uncommon subtype of benign tumors arising from the terminal branches of the vestibulocochlear nerve. Symptoms often include sensorineural hearing loss, dizziness, and tinnitus, and in this location, symptoms often arise at a small tumor size. In this featured case, we present a patient who underwent gross total tumor resection and cochlear implantation for hearing rehabilitation and treatment of tinnitus. Six months after surgery, the patient achieved good device performance, scoring 46% on consonant-nucleus-consonant word testing and 66% on AzBio sentence testing, and subjective improvement in his tinnitus.

Genomic markers of recurrence risk in atypical meningioma following gross total resection

Background

Meningiomas are the most common primary central nervous system (CNS) tumor in adults and CNS World Health Organization grade 2 (atypical) meningiomas show an intermediate risk of recurrence/progression. Molecular parameters are needed to better inform management following gross total resection (GTR).

Methods

We performed comprehensive genomic analysis of tumor tissue from 63 patients who underwent radiologically confirmed GTR of a primary grade 2 meningioma, including a CLIA-certified target next-generation sequencing panel (n = 61), chromosomal microarray (n = 63), genome-wide methylation profiling (n = 62), H3K27me3 immunohistochemistry (n = 62), and RNA-sequencing (n = 19). Genomic features were correlated with long-term clinical outcomes (median follow-up: 10 years) using Cox proportional hazards regression modeling and published molecular prognostic signatures were evaluated.

Results

The presence of specific copy number variants (CNVs), including -1p, -10q, -7p, and -4p, was the strongest predictor of decreased recurrence-free survival (RFS) within our cohort (P < .05). NF2 mutations were frequent (51%) but did not show a significant association with RFS. DNA methylation-based classification assigned tumors to DKFZ Heidelberg benign (52%) or intermediate (47%) meningioma subclasses and was not associated with RFS. H3K27 trimethylation (H3K27me3) was unequivocally lost in 4 tumors, insufficient for RFS analysis. Application of published integrated histologic/molecular grading systems did not improve prediction of recurrence risk over the presence of -1p or -10q alone.

Conclusions

CNVs are strong predictors of RFS in grade 2 meningiomas following GTR. Our study supports incorporation of CNV profiling into clinical evaluation to better guide postoperative patient management, which can be readily implemented using existing, clinically validated technologies.

Withdrawal of bevacizumab is associated with rebound growth of vestibular schwannomas in neurofibromatosis type 2-related schwannomatosis patients

Background

Neurofibromatosis type 2 (NF2)-related schwannomatosis is an autosomal dominant tumor-predisposition syndrome characterized by bilateral vestibular schwannomas (VS). In patients with VS associated with NF2, vascular endothelial growth factor A inhibitor, bevacizumab, is a systemic treatment option. The aim of this study is to retrospectively evaluate NF2 patient responses to bevacizumab on VS growth and symptom progression.

Methods

This is a retrospective analysis of patients seen at the Mayo Clinic Rochester Multidisciplinary NF2 Clinic.

Results

Out of 76 patients with NF2 evaluated between 2020 and 2022, we identified 19 that received treatment with bevacizumab. Thirteen of these patients discontinued bevacizumab after median treatment duration of 12.2 months. The remaining 6 patients are currently receiving bevacizumab treatment for a median duration of 9.4 months as of March, 2023. Fifteen patients had evaluable brain MRI data, which demonstrated partial responses in 5 patients, stable disease in 8, and progression in 2. Within 6 months of bevacizumab discontinuation, 5 patients had rebound growth of their VS greater than 20% from their previous tumor volume, while 3 did not. Three patients with rebound growth went on to have surgery or irradiation for VS management.

Conclusions

Our single-institution experience confirms prior studies that bevacizumab can control progression of VS and symptoms associated with VS growth. However, we note that there is the potential for rapid VS growth following bevacizumab discontinuation, for which we propose heightened surveillance imaging and symptom monitoring for at least 6 months upon stopping anti-VEGF therapy.

Temporal encephalocele: An epileptogenic focus confirmed by direct intracranial electroencephalography

Several studies have suggested the epileptogenic potential of temporal encephaloceles. However, there is limited literature describing the results of intracranial EEG monitoring for patients with temporal encephaloceles. We describe a 19 year-old right-handed woman with drug-resistant epilepsy who presented with seizure onset at age 16 in the setting of a left temporal encephalocele where the seizure onset zone was confirmed to be the encephalocele via stereo EEG (sEEG). She had focal impaired awareness seizures occurring weekly that would progress to focal to bilateral tonic-clonic seizures monthly. Imaging showed a left anterior inferior temporal lobe encephalocele and a left choroidal fissure cyst that were stable on repeat imaging. Prolonged scalp recorded video EEG recorded seizures that showed either near simultaneous onset in the bitemporal head regions or a transitional left temporal sharp wave followed by maximum evolution in the left temporal region. Invasive monitoring with sEEG electrodes targeting primarily the left limbic system with one electrode directly in the encephalocele captured seizures with onset in the left temporal pole encephalocele. A limited resection was performed based on the results of the sEEG and except for one seizure in the immediate postop period in the setting of infection, patient remains seizure free at her 4 month follow up. This report describes a case of drug-resistant focal epilepsy where sEEG monitoring confirmed a temporal encephalocele to be the seizure onset zone without simultaneous onset at mesial temporal or other neocortical structures that were sampled. Our findings support the potential for epileptogenicity within an encephalocele with direct intracranial monitoring.

Temporal Encephalocele: A Treatable Etiology of Drug-Resistant Pediatric Temporal Lobe Epilepsy

BACKGROUND

Temporal lobe encephaloceles (TEs) are a rare cause of drug-resistant temporal lobe epilepsy (DR-TLE), with head trauma and obesity identified as risk factors in adults. This study evaluated the clinical characteristics of childhood-onset DR-TLE due to TE.

METHODS

This is a single-institution retrospective review of childhood-onset DR-TLE with radiographic TE identified between 2008 and 2020. The epilepsy history, brain imaging features, and surgical outcomes were collected.

RESULTS

Eleven children with DR-TLE due to TE were included (median age at epilepsy onset was 11 years, interquartile range 8.5 to 13.5 years). Median latency between epilepsy diagnosis and TE detection was 3 years (range of 0 to 13 years). None had history of head trauma. Body mass index greater than 85 percentile for age and sex was seen in 36% of the children. No patient had bilateral TE identified. TEs were diagnosed based on epilepsy surgery conference re-review of imaging in 36% of cases. All herniations were contained defects without osseous dehiscence. Regional fluorodeoxyglucose (FDG) hypometabolism ipsilateral to the encephalocele was seen in all children who had FDG-positron emission tomography (PET) of the brain. Of the children who had surgery, 70% were seizure free or had nondisabling seizures at last follow-up (mean follow-up 52 months).

CONCLUSIONS

TE is a surgically remediable etiology of DR-TLE in childhood. TEs are often overlooked at pediatric epilepsy diagnosis, calling for the need to increase awareness of this entity. FDG-PET temporal hypometabolism in children with presumed nonlesional DR-TLE should be carefully examined for occult TEs.

Unrecognized notochordal lesions as a likely cause of idiopathic clival cerebrospinal fluid leaks

OBJECTIVE

To examine an association between idiopathic transclival cerebrospinal fluid (CSF) leak and notochordal lesions.

METHODS

This study consisted of the illustrations of institutional patients who underwent surgery for transclival CSF leak between January 1, 2009 and April 25, 2020 and comprehensive review of the existing literature conducted on April 25, 2020. The cases were classified based on the presumed etiologies that were originally proposed in the articles ("idiopathic" vs. "secondary"). The baseline characteristics were compared between the groups, and the surgical outcomes were summarized.

RESULTS

In 3 institutional cases, ecchordosis physaliphora (EP) was confirmed at the fistula either pathologically (1) or radiologically (2). Among 42 literature cases, 28 were recognized as idiopathic, while 14 were secondary cases with histologically (n = 12) or radiologically (n = 2) confirmed notochordal lesion at the fistula. Thus, any notochordal lesions were histologically confirmed in 13 among a total of 45 cases (28.9%). Fourteen of the idiopathic cases had undescribed radiographic signs suggestive of small ecchordosis physaliphora at the fistula. Both idiopathic and secondary cases demonstrated resemblance in their ages (mean, 51.4 and 56.6 years; p = 0.102), female predominance (male, 36% vs. 25%; P = 0.521), no association with obesity (7% vs. 18%; P = 0.350) or increased intracranial pressure (7% vs. 6%; P = 1.000). All the fistulas were in the midline or paramidline clivus within several millimeters below the dorsum sellae. All the patients were treated surgically with a multilayer closure, resulting in a success rate of 93% with one surgery.

CONCLUSION

Our analyses suggest the association of transclival CSF leak and notochord lesions. A prospective study is needed for definitive conclusion.

Invasive neuromodulation for epilepsy: Comparison of multiple approaches from a single center

BACKGROUND

Drug-resistant epilepsy (DRE) patients not amenable to epilepsy surgery can benefit from neurostimulation. Few data compare different neuromodulation strategies.

OBJECTIVE

Compare five invasive neuromodulation strategies for the treatment of DRE: anterior thalamic nuclei deep brain stimulation (ANT-DBS), centromedian thalamic nuclei DBS (CM-DBS), responsive neurostimulation (RNS), chronic subthreshold stimulation (CSS), and vagus nerve stimulation (VNS).

METHODS

Single center retrospective review and phone survey for patients implanted with invasive neuromodulation for 2004-2021.

RESULTS

N = 159 (ANT-DBS = 38, CM-DBS = 19, RNS = 30, CSS = 32, VNS = 40). Total median seizure reduction (MSR) was 61 % for the entire cohort (IQR 5-90) and in descending order: CSS (85 %), CM-DBS (63 %), ANT-DBS (52 %), RNS (50 %), and VNS (50 %); p = 0.07. The responder rate was 60 % after a median follow-up time of 26 months. Seizure severity, life satisfaction, and quality of sleep were improved. Cortical stimulation (RNS and CSS) was associated with improved seizure reduction compared to subcortical stimulation (ANT-DBS, CM-DBS, and VNS) (67 % vs. 52 %). Effectiveness was similar for focal epilepsy vs. generalized epilepsy, closed-loop vs. open-loop stimulation, pediatric vs. adult cases, and high frequency (>100 Hz) vs. low frequency (<100 Hz) stimulation settings. Delivered charge per hour varied widely across approaches but was not correlated with improved seizure reduction.

CONCLUSIONS

Multiple invasive neuromodulation approaches are available to treat DRE, but little evidence compares the approaches. This study used a uniform approach for single-center results and represents an effort to compare neuromodulation approaches.

Fluorescein-Assisted Microsurgical Resection of Vestibular Schwannoma: A Prospective Feasibility Study

OBJECTIVE

To evaluate the optimal dose and timing of administration of sodium fluorescein (SF) for selective fluorescence of sporadic vestibular schwannoma (VS) during microsurgery with the YELLOW 560-nm microscope filter (YE560) and to characterize the potential benefit of this fluorescence as determined by intraoperative surgeon assessment.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Adult patients undergoing VS microsurgery.

INTERVENTIONS

Intraoperative intravenous administration of SF and visualization with the YE560.

MAIN OUTCOME MEASURES

Time to differential fluorescence, duration of fluorescence, correlation of fluorescence of VS with electrostimulation and white light microscopy visual assessment, and likelihood of surgeons to use SF with the YE560 in future cases.

RESULTS

Novel use of SF and YE560 during microsurgery achieved selective fluorescence of VS with capabilities to differentiate nerve fascicles and tumor approximately 30 minutes after administration. Nuances of SF administration and timing are discussed. Seventy-five percent of surgeons observed an excellent correlation of selective fluorescence with white light microscopy. Representative images and cases are presented.

CONCLUSIONS

SF and YE560 may be used in VS microsurgery to visually differentiate VS from surrounding nerves. Potential benefits include enhanced visualization of the tumor-nerve interface for tumor dissection and detection of any residual disease, such as in the fundus after hearing preservation microsurgery.

Optimizing Quality of Life and Minimizing Morbidity through Nasal Preservation in Endoscopic Skull Base Surgery: A Contemporary Review

Introduction  Endoscopic endonasal approaches (EEAs) are increasingly utilized for intracranial pathology. As opposed to sinonasal tumors, the nasal cavity is being used as a corridor to access these intracranial tumors but is not the site of primary surgical intent. Accordingly, there has been recent interest in preserving intranasal structures not directly involved by tumor and improving postoperative sinonasal quality of life (QOL). Objectives  The aim of the study is to highlight recent advances in EEA techniques focused on improving sinonasal QOL including turbinate preservation, reducing the morbidity of reconstructive techniques, and the development of alternative minimally invasive EEA corridors. Methods  The method of the study involves contemporary literature review and summary of implications for clinical practice. Results  Nasoseptal flap (NSF) harvest is associated with significant morbidity including septal perforation, prolonged nasal crusting, and external nasal deformities. Various grafting and local rotational flaps have demonstrated the ability to significantly limit donor site morbidity. Free mucosal grafts have re-emerged as a reliable reconstructive option for sellar defects with an excellent sinonasal morbidity profile. Middle turbinate preservation is achievable in most EEA cases and has not been shown to cause postoperative obstructive sinusitis. Recently developed minimally invasive EEA techniques such as the superior ethmoidal approach have been described to better preserve intranasal structures while allowing intracranial access to resect skull base tumors and have shown promising sinonasal QOL results. Conclusion  This contemporary review discusses balancing effective skull base reconstructive techniques with associated morbidity, the role of turbinate preservation in EEA, and the development of unique EEA techniques that allow for increased nasal structure preservation.

Retrospective Review of Surgical Site Infections after Endoscopic Endonasal Sellar and Parasellar Surgery: Multicenter Quality Data from the North American Skull Base Society

Introduction  Transnasal access to the anterior skull base provides a minimally invasive approach for sellar and parasellar masses compared with its open counterparts. The unique microbiome of the sinonasal mucosa provides distinct challenges not encountered with other cranial approaches. The use of antibiotics in these cases has not been standardized, and data remain scarce regarding infectious outcomes. Methods  We conducted a multicenter retrospective analysis of shared quality data points for the endoscopic endonasal approach (EEA) for pituitary adenomas, along with other sellar and parasellar region masses that were included by participating institutions. Patient and operative characteristics, perioperative and postoperative antibiotic regimens and their durations, intraoperative and postoperative cerebrospinal fluid leak, and onset of postoperative meningitis and sinusitis were compared. Results  Fifteen institutions participated and provided 6 consecutive months' worth of case data. Five hundred ninety-three cases were included in the study, of which 564 were pituitary adenomectomies. The incidences of postoperative meningitis and sinusitis were low (0.67 and 2.87% for all pathologies, respectively; 0.35% meningitis for pituitary adenomas) and did not correlate with any specific antibiotic regimen. Immunocompromised status posed an increased odds of meningitis in pituitary adenomectomies (28.6, 95% confidence interval [1.72-474.4]). Conclusions  The results show no clear benefit to postoperative antimicrobial use in EEA, with further larger studies needed.

Systematic review and patient-level meta-analysis of radiofrequency ablation for medically refractory epilepsy: Implications for clinical practice and research

BACKGROUND

Radiofrequency thermocoagulation (RF-TC) is a minimally invasive procedure for the treatment of epileptic foci. The aim of this study is to review available evidence on the safety and efficacy of RF-TC for medically refractory epilepsy.

METHODS

A comprehensive literature search (Pubmed/Medline, EMBASE, Cochrane) was conducted for studies with patient-level data on RF-TC for medically refractory epilepsy. Seizure outcome (Engel classification) at last follow-up comprised the primary endpoint. New temporary or permanent post-procedural neurological deficits were the secondary endpoints.

RESULTS

A total of 20 studies (360 patients) were analyzed. Median age at the time of intervention was 29 years (interquartile range (IQR): 21-37) and 57% were males. A lesional MRI was noted in 59% of patients. Median duration of postoperative follow-up was 24 months (IQR: 11-48). The median number of RF-TC lesions per patient was 11 (IQR: 6-19), with bipolar ablation (i.e. between two contiguous contacts) being the most common method (n = 244, 68%). The most common RF-TC location was the mesial temporal structures, without (34%) or with (7%) the temporal neocortex, followed by the insula (13%) and the frontal lobe (12%). Multilobar targets were lesioned in 11% of patients. New neurological deficits developed in 10% of patients (2% remained permanently), with the most common being motor deficits. Among patients with at least 12 months of follow-up (n = 267, 74% of overall cohort), a favorable seizure outcome (Engel I/II class) was achieved in 62% of cases. Patients with a favorable seizure outcome were significantly more likely to have a lesional MRI (71% vs 43% 51%, p < 0.001), have a higher number of RF ablations (15 [IQR 8-31] vs 9 [IQR 4-14], p < 0.001), and undergo monopolar RF-TC (50% vs 30%, p = 0.002).

CONCLUSION

Current evidence supports the promising safety and efficacy profile of RF-TC for medically refractory epilepsy. Randomized controlled trial data are needed to further establish the role of this intervention in preoperative discussions with patients and their families.

Safety and Management of Implanted Epilepsy Devices for Imaging and Surgery

Permanently implanted devices that deliver electrical stimulation are increasingly used to treat patients with drug-resistant epilepsy. Primary care physicians, neurologists, and epilepsy clinicians may encounter patients with a variety of implanted neuromodulation devices in the course of clinical care. Due to the rapidly changing landscape of available epilepsy-related neurostimulators, there may be uncertainty related to how these devices should be handled during imaging procedures and perioperative care. We review the safety and management of epilepsy-related implanted neurostimulators that may be encountered during imaging and surgery. We provide a summary of approved device labeling and recommendations for the practical management of these devices to help guide clinicians as they care for patients treated with bioelectronic medicine.

High Long-Term Mortality Rate in Elderly Patients with Mild Traumatic Brain Injury and Subdural Hematoma due to Ground-Level Fall: Neurosurgery's Hip Fracture?

BACKGROUND

Moderate-to-severe traumatic brain injury (TBI) is a major source of morbidity and mortality in elderly patients. Little is known about long-term mortality in elderly patients following mild, nonfatal TBI and how the injury mechanism predicts survival. This study aimed to compare long-term mortality in elderly patients with mild TBI and traumatic subdural hematoma (tSDH) due to ground-level fall (GLF) versus those with TBI and tSDH due to another cause (i.e., non-ground-level fall [nGLF]).

METHODS

This retrospective study comprised 288 patients ≥60 years old from a single Level I trauma center with tSDH and Glasgow Coma Scale scores 13-15.

RESULTS

Median follow-up after initial TBI presentation was 2.9 years for the GLF group and 2.4 years for the nGLF group. During follow-up, 98 patients died, and median survival for all elderly patients with mild TBI and tSDH was 4.6 years. The GLF group had a higher mortality rate than the nGLF group, with 93 patients in GLF group dying during follow-up compared with 5 in nGLF group (P < 0.0001). The annual death rate for patients in the GLF group was 12.5% per year. For patients 60-69 years old, 39% in GLF group died compared with 4% in nGLF group during follow-up (P = 0.0002). Likewise, for patients 70-79 years old, 29% in GLF group died compared with 7% in nGLF group (P = 0.021). Finally, 56% of patients >80 years old in GLF group compared with 18% in nGLF group (P = 0.11).

CONCLUSIONS

Elderly patients with mild TBI and tSDH due to GLF have significantly higher long-term mortality than patients with injuries due to nGLF.