Extradural malignant rhabdoid tumor of the spine in children: A case-based review

BACKGROUND

Extradural malignant rhabdoid tumors of the spine are highly malignant and invasive tumors (WHO grade IV) with poor prognosis, most frequently occurring in young children before 2 years of age. Pain and motor deficit are the most common presenting signs.

CASE DESCRIPTION

We report a case of a 2-year-old girl presenting with axial ataxia and paraparesis related to an extradural malignant rhabdoid tumor causing posterior thoracic spinal cord compression (D3-D6). She underwent two near-total removal of the tumor, adjuvant chemotherapy according to the Eu-Rhab protocol and proton beam therapy. She then developed multiple cranial nerve paresis (meningeal carcinomatosis) after 4 cycles of chemotherapy and died at 4.32 months of follow-up.

DISCUSSION AND CONCLUSION

The role of the PET scan was essential to guide us to remove a residue, while two concomitant spinal MRIs were considered negative. We reviewed the 16 cases reported in the literature. Multiple surgeries and radiotherapy seem to be correlated with longer survival. No child younger than 2 years old had a documented survival higher than 4.32 months.

DIAPH3 predicts survival of patients with MGMT-methylated glioblastoma

Background

Glioblastoma is one of the most aggressive primary brain tumors, with a poor outcome despite multimodal treatment. Methylation of the MGMT promoter, which predicts the response to temozolomide, is a well-established prognostic marker for glioblastoma. However, a difference in survival can still be detected within the MGMT methylated group, with some patients exhibiting a shorter survival than others, emphasizing the need for additional predictive factors.

Methods

We analyzed DIAPH3 expression in glioblastoma samples from the cancer genome atlas (TCGA). We also retrospectively analyzed one hundred seventeen histological glioblastomas from patients operated on at Saint-Luc University Hospital between May 2013 and August 2019. We analyzed the DIAPH3 expression, explored the relationship between mRNA levels and Patient's survival after the surgical resection. Finally, we assessed the methylation pattern of the DIAPH3 promoter using a targeted deep bisulfite sequencing approach.

Results

We found that 36% and 1% of the TCGA glioblastoma samples exhibit copy number alterations and mutations in DIAPH3, respectively. We scrutinized the expression of DIAPH3 at single cell level and detected an overlap with MKI67 expression in glioblastoma proliferating cells, including neural progenitor-like, oligodendrocyte progenitor-like and astrocyte-like states. We quantitatively analyzed DIAPH3 expression in our cohort and uncovered a positive correlation between DIAPH3 mRNA level and patient's survival. The effect of DIAPH3 was prominent in MGMT-methylated glioblastoma. Finally, we report that the expression of DIAPH3 is at least partially regulated by the methylation of three CpG sites in the promoter region.

Conclusion

We propose that combining the DIAPH3 expression with MGMT methylation could offer a better prediction of survival and more adapted postsurgical treatment for patients with MGMT-methylated glioblastoma.

Neurological outcome following delayed traction and fixation in severe tetraparesis consecutive to posterior decompression for Chiari malformation: a case report

BACKGROUND

Chiari malformation type 1 (CM1) is a congenital hindbrain malformation characterized by herniation of the cerebellar tonsils below the foramen magnum. The term Chiari type 1.5 is used when herniation of the brainstem under the McRae line and anomalies of the craniovertebral junction are also present. These conditions are associated with several symptoms and signs, including headache, neck pain, and spinal cord syndrome. For symptomatic patients, surgical decompression is recommended. When radiographic indicators of craniovertebral junction (CVJ) instability or symptoms related to ventral brainstem compression are present, CVJ fixation should also be considered.

CASE DESCRIPTION

We report the case of a 13-year-old girl who presented with severe tetraparesis after posterior decompression for Chiari malformation type 1.5, followed 5 days later by partial C2 laminectomy. Several months after the initial surgery, she underwent two fixations, first without and then with intraoperative cervical traction, leading to significant neurological improvement.

DISCUSSION AND CONCLUSION

This case report underscores the importance of meticulous radiological analysis before CM surgery. For CM 1.5 patients with basilar invagination, CVJ fixation is recommended, and C2 laminectomy should be avoided. In the event of significant clinical deterioration due to nonadherence to these guidelines, our findings highlight the importance of traction with increased extension before fixation, even years after initial destabilizing surgery.

Development of an online calculator for the prediction of seizure freedom following pediatric hemispherectomy using the Hemispherectomy Outcome Prediction Scale (HOPS)

OBJECTIVES

Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy.

METHODS

Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/).

RESULTS

The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%.

SIGNIFICANCE

Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

How to reduce the complication rate of multiple burr holes surgery in moyamoya angiopathy

PURPOSE

This study is aimed at analyzing clinical outcome, absence of stroke recurrence, revascularization, and complications and long-term follow-up in the surgical treatment of moyamoya angiopathy (MMA) using the multiple burr holes (MBH) technique with dura opening and arachnoid preservation as a single procedure. To the best of our knowledge, this is the first to describe an MBH technique with arachnoid preservation.

METHOD

We retrospectively reviewed all patients operated from June 2001 to March 2021, for a symptomatic and progressive MMA operated with opening of the dura but arachnoid preservation. Clinical examinations were obtained in all patients, and radiological monitoring was performed by cerebral 3D-magnetic resonance angiography (MRA) with perfusion or single-photon emission computed tomography (SPECT) with acetazolamide.

RESULTS

In total, 21 consecutive patients (6 children and 15 adults) were included with a mean age of 7.4 years in the pediatric group and 36.9 years in the adult group. Initial presentation was permanent ischemic stroke in 15 cases, transient ischemic attack (TIA) in 5 cases, and cerebral hemorrhage in one case. The MBH with dura opening and arachnoid preservation was performed bilaterally in 9 cases (43%) and unilaterally in 12 cases (57%). One patient died due to intraoperative bilateral ischemic stroke. Of the 20 other patients, 30% demonstrated clinical stability and 70% showed partial or complete recovery. Although one patient experienced a perioperative stroke, we did not observe any pseudomeningocele or postoperative ischemic stroke (IS) recurrence in all surviving cases during the average follow-up period of 55.5 months (range: 1-195). These outcomes emphasize the importance of preoperative monitoring to ensure the effectiveness and safety of the intervention. Postoperative angiography studies showed revascularization in 96.3% of treated hemispheres (100% in the adult group vs 80% in the pediatric group).

CONCLUSIONS

Our results on this small cohort suggest that the MBH technique with opening of the dura and arachnoids preservation can prevent recurrent strokes and reduce the risk of pseudomeningocele.

Natural history and surgical outcome of incidentally discovered clinically nonfunctioning pituitary macroadenomas

Objectives

The incidental diagnosis of nonfunctioning pituitary macroadenomas (NFPMAs) is becoming more prevalent with the spread of modern brain imaging techniques. We sought to uncover new data about their natural history and surgical outcome.

Design

This is a retrospective single-center observational study.

Methods

Among 210 patients seen for a NFPMA between 2010 and 2019, 70 (33%) were discovered incidentally (i-NFPMA). We analyzed outcomes in a total of 65 patients with available follow-up data.

Results

Mean age at diagnosis (± s.d.) was 60 ± 14 years and mean maximal diameter was 20.0 ± 7.3 mm. At diagnosis, 29 patients (45%) had pituitary hormone deficits (LH/FSH 41%, TSH 29%, ACTH 15%) and 12% had visual field deficits. 26 patients underwent initial surgery, while 12 had delayed surgery after initial surveillance. In the surveillance group, the risk of tumor growth was estimated at 10%/year. Patients with hormonal deficits at diagnosis experienced earlier growth at 24 months (P < 0.02). Overall, surgical resection of the i-NFPMA led to stable or improved endocrine function in 91% of patients, with only 6% postoperative permanent diabetes insipidus. Moreover, surgery was more effective in preserving intact endocrine function (10/12) than restoring altered endocrine function to normal (6/22, P = 0.03).

Conclusion

About one-third of NFPMAs are now discovered incidentally and a significant subset may be responsible for unrecognized endocrine and visual deficits. Under surveillance the risk of further tumor growth is significant (10%/year) and seems to occur faster in patients already harboring an endocrine deficit. Early surgical removal before onset of endocrine deficits appears to lead to better endocrine outcome.

Modified Vertical Parasagittal Sub-Insular Hemispherotomy-Case Series and Technical Note

(1) Background: Hemispherotomy is the generally accepted treatment for hemispheric drug-resistant epilepsy (DRE). Lateral or vertical approaches are performed according to the surgeon's preference. Multiple technical variations have been proposed since Delalande first described his vertical technique. We propose a sub-insular variation of the vertical parasagittal hemispherotomy (VPH) and describe our case series of patients operated on using this procedure. (2) Methods: Data from a continuous series of patients with hemispheric DRE who were operated on by the senior author (CR) using the modified sub-insular VPH technique were analyzed retrospectively. Pre-operative demographic and epilepsy characteristics, functional outcome, and surgical complications were extracted from medical charts. (3) Results: Twenty-five patients were operated on between August 2008 and August 2023; 23 have at least 3 months of follow-up. Of this group, 20 (86.9%) patients are seizure-free. Only two patients developed postoperative hydrocephalus (8.7%). All patients who were able to walk autonomously preoperatively and 20 (86.9%) of those with follow-up were able to walk without assistance. A total of 17 (74%) patients were able to perform adapted social activities at the latest follow-up. (4) Conclusions: Modified sub-insular VPH is a successful surgical technique for hemispheric DRE with seizure freedom rates similar to the largest series reported in the literature. Compared to other series, patients who were operated on with our modified technique had a lower rate of postoperative hydrocephalus and excellent long-term motor and cognitive outcomes.

Clinical added value of interictal automated electrical source imaging in the presurgical evaluation of MRI-negative epilepsy: A real-life experience in 29 consecutive patients

OBJECTIVE

During the presurgical evaluation, manual electrical source imaging (ESI) provides clinically useful information in one-third of the patients but it is time-consuming and requires specific expertise. This prospective study aims to assess the clinical added value of a fully automated ESI analysis in a cohort of patients with MRI-negative epilepsy and describe its diagnostic performance, by evaluating sublobar concordance with stereo-electroencephalography (SEEG) results and surgical resection and outcome.

METHODS

All consecutive patients referred to the Center for Refractory Epilepsy (CRE) of St-Luc University Hospital (Brussels, Belgium) for presurgical evaluation between 15/01/2019 and 31/12/2020 meeting the inclusion criteria, were recruited to the study. Interictal ESI was realized on low-density long-term EEG monitoring (LD-ESI) and, whenever available, high-density EEG (HD-ESI), using a fully automated analysis (Epilog PreOp, Epilog NV, Ghent, Belgium). The multidisciplinary team (MDT) was asked to formulate hypotheses about the epileptogenic zone (EZ) location at sublobar level and make a decision on further management for each patient at two distinct moments: i) blinded to ESI and ii) after the presentation and clinical interpretation of ESI. Results leading to a change in clinical management were considered contributive. Patients were followed up to assess whether these changes lead to concordant results on stereo-EEG (SEEG) or successful epilepsy surgery.

RESULTS

Data from all included 29 patients were analyzed. ESI led to a change in the management plan in 12/29 patients (41%). In 9/12 (75%), modifications were related to a change in the plan of the invasive recording. In 8/9 patients, invasive recording was performed. In 6/8 (75%), the intracranial EEG recording confirmed the localization of the ESI at a sublobar level. So far, 5/12 patients, for whom the management plan was changed after ESI, were operated on and have at least one-year postoperative follow-up. In all cases, the EZ identified by ESI was included in the resection zone. Among these patients, 4/5 (80%) are seizure-free (ILAE 1) and one patient experienced a seizure reduction of more than 50% (ILAE 4).

CONCLUSIONS

In this single-center prospective study, we demonstrated the added value of automated ESI in the presurgical evaluation of MRI-negative cases, especially in helping to plan the implantation of depth electrodes for SEEG, provided that ESI results are integrated into the whole multimodal evaluation and clinically interpreted.

Long-term survival in patients with IDH-wildtype glioblastoma: clinical and molecular characteristics

BACKG ROUND

Glioblastoma is an aggressive tumor that has a dismal prognosis even with multimodal treatment. However, some patients survive longer than expected. The objective of this study was to revisit patients diagnosed with glioblastoma according to the 2021 WHO classification and analyze clinical and molecular characteristics associated with long-term survival (LTS).

METHODS

We retrospectively analyzed 120 IDH-wildtype glioblastomas operated on at our institution between 2013 and 2018. We divided them into LTS patients, surviving more than 3 years, and non-LTS patients, and then compared their features. Additionally, we performed DNA methylation-based brain tumor classification in LTS patients.

RESULTS

Sixteen patients were long-term survivors. Age < 70 years, MGMT promoter methylation, extent of resection ≥ 95%, and administration of radiochemotherapy were associated with LTS (P = 0.005, P < 0.001, P = 0.048, and P = 0.008, respectively). In addition, when these factors were combined, the probability of LTS was 74% (95% CI: 62--84). The methylome analysis confirmed the diagnosis of glioblastoma in the majority of the tested LTS patients. Regarding subtypes, 29% of cases were mesenchymal (MES), 43% were RTK1, and 29% were RTK2. Interestingly, RTK1 and RTK2 cases tended to have longer overall survival than MES cases (P = 0.057). Moreover, the only tested LTS patient with an unmethylated MGMT promoter had an "adult-type diffuse high-grade glioma, IDH-wildtype, subtype E" rather than a glioblastoma. This tumor was characterized by multinucleated giant cells and a somatic mutation in POLE.

CONCLUSIONS

We suggest that glioblastoma patients with a combination of favorable prognostic factors can achieve LTS in 74% of cases. In addition, methylome analysis is important to ascertain the type of glioma in LTS patients, especially when the MGMT promoter is unmethylated.

Stereo-electroencephalography implantation using frameless neuronavigation and Varioguide®: prospective analysis of accuracy and safety in a case-series of 11 patient

BACKGROUND

Stereoencephalography (SEEG) is becoming a widespread diagnostic procedure for drug-resistant epilepsy investigation. Techniques include frame-based and robot-assisted implantation, and more recently, frameless neuronavigated systems (FNS). Despite its recent use, the accuracy and safety of FNS are still under investigation.

OBJECTIVE

To assess in a prospective study the accuracy and safety of a specific FNS use for SEEG implantation.

METHODS

Twelve patients who underwent SEEG implantation using FNS (Varioguide ® - Brainlab) were included in this study. Data were collected prospectively and included demographic data, postoperative complications, functional results, and implantation characteristics (i.e. duration, number of electrodes). Further analysis included accuracy at entry point and target using measurements of the Euclidian distance between planned and actual trajectories.

RESULTS

Eleven patients underwent SEEG-FNS implantation from May 2019 to March 2020. One patient did not undergo surgery due to a bleeding disorder. The mean target deviation was 4.06 mm, and mean entry point deviation was 4.2 mm, with insular electrodes significantly more deviated. Results excluding insular electrodes showed a mean target deviation of 3.66mm and a mean entry point deviation of 3.77mm. No severe complications occurred; a few mild to moderate adverse events were reported (1 superficial infection, 1 seizure cluster and 3 transient neurological impairments). The mean implantation duration by electrodes was 18.5 minutes.

CONCLUSION

Implantation of depth electrodes for SEEG using a FNS appears to be safe, but larger prospective studies are needed to validate these results. Accuracy is sufficient for non-insular trajectories but warrant caution for insular trajectories with statistically significantly less accuracy.

Second surgery after vertical paramedian hemispherotomy for epilepsy recurrence

Background

Vertical Paramedian Hemispherotomy (VPH) is considered an effective surgical treatment for drug-resistant epilepsy with 80% of patients experiencing seizure freedom or worthwhile improvement. Identifying persistent connective tracts is challenging in failed VPH.

Methods

We reviewed our series of consecutive patients undergoing VPH for hemispheric drug-resistant epilepsy and included cases with recurrent epileptic seizures undergoing second surgery with at least 6 months of postoperative follow-up. The cases were extensively assessed to propose a targeted complementary resection.

Results

Two children suffering from seizure recurrence following hemispherotomy leading to second surgery were included. After complete assessment, persisting amygdala residue was suspected responsible for the epilepsy recurrence in both patients. Complementary resection of the amygdala residue led to seizure freedom for both patients (Engel IA/ILAE Class 1) without complication. Different diagnostic tools are used to assess patients after failed hemispherotomy including routine EEG, prolonged video EEG, MRI (particularly DTI sequences), SPECT or PET scans and clinical evaluation. These tools allow to rule out epileptic foci in the contralateral hemisphere and to localize a potentially persisting epileptogenic zone. Assessment of these patients should be as systematic and integrated as the initial workup. Although our two patients suffered from Rasmussen's encephalitis, seizure recurrence after VPH has been described in other pathologies.

Conclusion

Lying deep and medially in the surgical corridor of VPH, the amygdala can be incompletely resected and cause recurrent epilepsy. Complementary selective resection of the amygdala residue may safely lead to success in epilepsy control.

Ectopic sphenoidal ACTH-secreting adenoma revealed by 11C Methionine PET scan: case report

BACKGROUND

Ectopic ACTH pituitary adenomas (EAPA), located outside the sella turcica and deriving from cellular remnants of Rathke's pouch are a very rare cause of Cushing's syndrome (CS). The diagnosis is often difficult and delayed, even after comprehensive work-up. To our knowledge, we report for the first time an ectopic corticotroph tumor of the posterior wall of the sphenoid sinus, leading to false positive results of bilateral inferior petrosal sinus sampling (BIPPS) and which was finally localized by a co-registered¹¹ C Methionine PET/MR imaging.

CASE PRESENTATION

A 48-year-old woman was referred for a high clinical suspicion of ACTH-dependent CS. Biological testing comprising low dose dexamethasone suppression and CRH stimulation tests were indicative of pituitary Cushing's disease, but comprehensive pituitary MRI did not reveal any pituitary adenoma. BIPSS confirmed however a central origin of ACTH secretion (central-to-peripheral ACTH ratio > 100) and revealed a significant right-to-left gradient (6.2), leading to a first right-sided exploratory hypophysectomy, that did not cure the patient. BIPSS images were reviewed and revealed preferential drainage of the left pituitary to the right petrosal sinus, leading us to a left sided exploratory hypophysectomy, which was again unsuccessful. A¹¹ C Methionine PET/MRI was performed and revealed a hypermetabolic lesion adjacent to the posterior wall of the sphenoidal sinus. After surgical resection, this polypoid mass was identified as an ectopic ATCH-secreting pituitary adenoma expressing ACTH and T-Pit and complete remission of hypercortisolism was observed.

CONCLUSIONS

In conclusion, we report a case of ACTH-dependent Cushing's syndrome, caused by an ectopic corticotroph adenoma located in the sphenoidal sinus, which perfectly mimicked the biological features of a classical pituitary ACTH adenoma on a comprehensive hormonal evaluation including BIPPS, and the features of a benign naso-sinusal polyp at MRI. We report for the first time a key role of¹¹ C Methionine PET co-registered to high resolution MRI for localizing ectopic adenomas, efficiently guiding surgical removal and leading to complete remission of hypercortisolism.

P10.02.B The fragile balance between proliferation and neoplasia in neural stem cells: role of DIAPH3 in glioblastoma

Background

DIAPH3 belongs to the formin family of proteins that are master regulators of the cell cytoskeleton. DIAPH3 plays a key role in cytokinesis as well karyokinesis. Hence, in the mouse brain, DIAPH3-deficient neural stem cells exhibit abnormal cell division leading to aneuploidy and apoptosis of cells progeny. Given the importance of aneuploidy in cancer development and progression, we asked whether DIAPH3 loss could be involved in the genesis and the aggressiveness of brain tumors.

Material and Methods

We co-inactivated Diaph3 and Trp53 genes in the mouse cerebral cortex using the Emx1-Cre mouse line (Diaph3/Trp53 dcKO). As a control, we inactivated only Trp53 gene using the same Cre mouse line (Trp53 cKO). Mouse survival was analyzed, and tumors were collected for histological analysis as well as molecular characterization. Additionally, we measured DIAPH3 expression in human glioblastoma samples and studied its impact on patient overall survival.

Results

Diaph3/Trp53 dcKO develop brain tumors earlier compared to Trp53 cKO resulting in a decrease of mouse survival. Hematoxylin-eosin staining, as well as GFAP, OLIG2 and KI67 immunostainings strongly suggest that the tumors are glioblastomas. Quantitative reverse transcription PCR performed on biopsies from 73 patients uncover variable DIAPH3 expression levels in glioblastoma samples. Interestingly, multivariate Cox proportional-hazards analysis shows that low DIAPH3 expression predicts a worse overall survival, independently from other known prognosis factors.

Conclusion

On one hand, our study shows that DIAPH3 loss favors glioblastoma development in mouse, strongly suggesting a tumor-suppressor role for DIAPH3. On the other hand, the clinical study shows that DIAPH3 low expression has a negative impact on patient overall survival indicating that DIAPH3 loss may favor resistance to chemotherapy and/or radiotherapy.

Randomized Trial Comparing Burr Hole Craniostomy, Minicraniotomy, and Twist Drill Craniostomy for Treatment of Chronic Subdural Hematoma

BACKGROUND

The mainstay of treatment for symptomatic or large chronic subdural hematoma (CSDH) is surgery, but controversy still exists regarding the best surgical technique. Three different techniques are commonly used: burr hole craniostomy (BHC), minicraniotomy (MC), and twist drill craniostomy (TDC).

OBJECTIVE

To determine which surgical technique for drainage of CSDH offers best results.

METHODS

We set up a multicenter prospective randomized trial (Comparison of Chronic Subdural Hematoma Treatment [COMPACT] trial) comparing BHC, MC, and TDC for the surgical treatment of CSDH. The primary end point was reoperation rate, and secondary end points included complication rates and clinical outcome. Patients were considered to have good outcome when they did not undergo reoperation, suffered no surgical or medical complication, and had no related mortality. Clinical outcome was also evaluated by evolution of the Markwalder score and the modified Rankin score.

RESULTS

Two-hundred forty-five patients were included in the final analysis: 79 BHC, 84 MC, and 82 TDC. Mean duration of surgery was shorter for TDC than for BHC and MC (P < .001). Reoperation rate was 7.6% for BHC, 13.1% for MC, and 19.5% for TDC (P = .07). This trend toward better results for BHC was not statistically significant in logistic regression analysis. The proportion of patients with good outcome was 78.5% for BHC group, 76.2% for MC, and 69.5% for TDC (P = .4). Evolution of the Markwalder score and modified Rankin score were not significantly different between treatment groups.

CONCLUSION

All 3 techniques are effective at treating patients with CSDH with eventual 6-month outcome being similar. Although not reaching statistical significance in our study, BHC offers the lowest recurrence rate combined with manageable complication rate.

Enhancing Safety in Epilepsy Surgery (EASINESS): Study Protocol for a Retrospective, Multicenter, Open Registry

Introduction: Optimizing patient safety and quality improvement is increasingly important in surgery. Benchmarks and clinical quality registries are being developed to assess the best achievable results for several surgical procedures and reduce unwarranted variation between different centers. However, there is no clinical database from international centers for establishing standardized reference values of patients undergoing surgery for mesial temporal lobe epilepsy.

Design: The Enhancing Safety in Epilepsy Surgery (EASINESS) study is a retrospectively conducted, multicenter, open registry. All patients undergoing mesial temporal lobe epilepsy surgery in participating centers between January 2015 and December 2019 are included in this study. The patient characteristics, preoperative diagnostic tools, surgical data, postoperative complications, and long-term seizure outcomes are recorded.

Outcomes: The collected data will be used for establishing standardized reference values (“benchmarks”) for this type of surgical procedure. The primary endpoints include seizure outcomes according to the International League Against Epilepsy (ILAE) classification and defined postoperative complications.

Discussion: The EASINESS will define robust and standardized outcome references after amygdalohippocampectomy for temporal lobe epilepsy. After the successful definition of benchmarks from an international cohort of renowned centers, these data will serve as reference values for the evaluation of novel surgical techniques and comparisons among centers for future clinical trials.

Clinical trial registration: This study is indexed at clinicaltrials.gov (NT 04952298).

The trans superior temporal gyrus approach for selective amygdalohippocamptectomy

BACKGROUND AND OBJECTIVE

Different surgical approaches have been described for selective amygdalohippocampectomy (SeAH) in patients with pharmacoresistant temporal lobe epilepsy (TLE). We report the results of the innovative trans-superior temporal gyrus (trans-STG) approach in a monocentric patients' series.

METHODS

We reviewed the patients' characteristics, post-operative outcomes, and complications in a series of 8 consecutive TLE patients operated on using the trans-STG approach and recruited between November 2015 and April 2017.

RESULTS

Over a mean 2,5-year follow-up period, 7/8 patients (87,5%) remained seizure-free (Engel 1). Only one (12,5%) was not cured (Engel 3) without clear explanation for treatment failure. Mean operative time was 237 minutes, representing a shortage of 80 minutes when compared to our historic trans-sylvian approach. No peri-operative death was recorded nor visual field defect/visual acuity impairment due to the approach. One patient suffered from a left posterior thalamo-capsular stroke.

CONCLUSION

Trans-STG approach is feasible, fast, and safefor SeAH in drug refractory TLE patients. This approach allows preservation of the optic radiation but cuts part of the uncinate fasciculus and potentially the anterior aspect of the anterior bundle of the midlle longitudinal fasciculus.

Automated electrical source imaging with scalp EEG to define the insular irritative zone: Comparison with simultaneous intracranial EEG

OBJECTIVE

To evaluate the accuracy of automatedinterictallow-density electrical source imaging (LD-ESI) to define the insular irritative zone (IZ) by comparing the simultaneous interictal ESI localization with the SEEG interictal activity.

METHODS

Long-term simultaneous scalp electroencephalography (EEG) and stereo-EEG (SEEG) with at least one depth electrode exploring the operculo-insular region(s) were analyzed. Automated interictal ESI was performed on the scalp EEG using standardized low-resolution brain electromagnetic tomography (sLORETA) and individual head models. A two-step analysis was performed: i) sublobar concordance betweencluster-based ESI localization and SEEG-based IZ; ii) time-locked ESI-/SEEG analysis. Diagnostic accuracy values were calculated using SEEG as reference standard. Subgroup analysis wascarried out, based onthe involvement of insular contacts in the seizure onset and patterns of insular interictal activity.

RESULTS

Thirty patients were included in the study. ESI showed an overall accuracy of 53% (C.I. 29-76%). Sensitivity and specificity were calculated as 53% (C.I. 29-76%), 55% (C.I. 23-83%) respectively. Higher accuracy was found in patients with frequent and dominant interictal insular spikes.

CONCLUSIONS

LD-ESI defines with good accuracy the insular implication in the IZ, which is not possible with classical interictalscalpEEG interpretation.

SIGNIFICANCE

Automated LD-ESI may be a valuable additional tool to characterize the epileptogenic zone in epilepsies with suspected insular involvement.

Comparison of the real-world effectiveness of vertical versus lateral functional hemispherotomy techniques for pediatric drug-resistant epilepsy: A post hoc analysis of the HOPS study

Objective

This study was undertaken to determine whether the vertical parasagittal approach or the lateral peri‐insular/peri‐Sylvian approach to hemispheric surgery is the superior technique in achieving long‐term seizure freedom.

Methods

We conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri‐insular/peri‐Sylvian, or lateral trans‐Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time‐to‐event method and calculated using the Kaplan–Meier survival method.

Results

Data for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri‐insular/peri‐Sylvian or trans‐Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%–70.2%) of the entire cohort at 10‐year follow‐up. Seizure freedom was 88.8% (95% CI = 78.9%–94.3%) at 1‐year follow‐up and persisted at 85.5% (95% CI = 74.7%–92.0%) across 5‐ and 10‐year follow‐up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%–91.5%) at 1‐year to 72.1% (95% CI = 66.9%–76.7%) at 5‐year to 57.2% (95% CI = 46.6%–66.4%) at 10‐year follow‐up for the lateral subgroup. Log‐rank test found that vertical hemispherotomy was associated with durable seizure‐free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time‐to‐seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08–6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05–12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique.

Significance

This pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise‐based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long‐term seizure outcomes.

Outcome of pituitary hormone deficits after surgical treatment of nonfunctioning pituitary macroadenomas

OBJECTIVES

Nonfunctionning pituitary macroadenomas (NFPMA) are benign tumors that cause symptoms of mass effects including hypopituitarism. Their primary treatment is transsphenoidal surgery. We aimed to determine the outcome of pituitary hormone deficits after surgical treatment of NFPMA and to identify factors predicting hormonal recovery.

DESIGN

We retrospectively included 246 patients with NFPMA diagnosed and operated in one of the two participating centers. All hormonal axes were evaluated except growth hormone (GH). Postoperative improvement of pituitary endocrine function was considered if at least one hormonal deficit had recovered and a lower total number of deficits was observed 1 year after surgery.

RESULTS

80% (n = 197) of patients had one or more pituitary deficits and 28% had complete anterior hypopituitarism. Besides GH, the gonadotropic and thyrotropic axes were the most commonly affected (68% and 62%, respectively). The number of hypopituitary patients dropped significantly to 61% at 1 year (p < 0.001) and a significant improvement was observed for all hormonal axes, except central diabetes insipidus. Among patients with preoperative hypopituitarism, 88/175 (50%) showed improved pituitary function at 1 year. Both hyperprolactinemia at diagnosis and a lower tumor diameter independently predicted favorable endocrine outcome.

CONCLUSIONS

Hypopituitarism is present in 80% of patients with NFPMA and nearly half of them will benefit from sustained improvement after surgery. Hyperprolactinaemia at diagnosis and lower tumor dimensions are associated with favorable endocrine prognosis. This supports the option of early surgery in NFPMA patients with pituitary deficits independent of the presence of visual disturbances.

Functional Prognostic value of optical coherence tomography in optic chiasmal decompression: A preliminary study

PURPOSE

To assess the predictive value for functional recovery of Ganglion Cell Complex Layer (GCC) and Retinal Nerve Fiber Layer (RNFL) measurements obtained by Optical Coherence Tomography (OCT) in patients undergoing chiasmal decompression and to define potential OCT thresholds for visual recovery.

METHODS

We measured preoperative GCC and RNFL thickness in patients with a sellar and/or perisellar tumor compressing the optic chiasm. Visual recovery was defined as recovery of mean deviation (MD) and pattern standard deviation (PSD) using Humphrey visual field testing after 12 successful decompressions (24 eyes). Receiver operating characteristic curve (ROC) analysis was used to identify the best thresholds.

RESULTS

Robust global and focal OCT thresholds were found. Superior GCC≥63μm had the best functional prognostic value (AUC=1) for visual improvement. Mean GCC ≥ 67μm and mean RNFL≥75μm also had excellent predictive values (AUC>0.9).

CONCLUSION

In this preliminary study, significant preoperative OCT thresholds for early visual recovery after chiasmal decompression were identified, mainly regarding GCC measurements. Further studies on larger cohorts with closely scheduled follow-up could refine our results.

Insular responses to transient painful and non-painful thermal and mechanical spinothalamic stimuli recorded using intracerebral EEG

Brief thermo-nociceptive stimuli elicit low-frequency phase-locked local field potentials (LFPs) and high-frequency gamma-band oscillations (GBOs) in the human insula. Although neither of these responses constitute a direct correlate of pain perception, previous findings suggest that insular GBOs may be strongly related to the activation of the spinothalamic system and/or to the processing of thermal information. To disentangle these different features of the stimulation, we compared the insular responses to brief painful thermonociceptive stimuli, non-painful cool stimuli, mechano-nociceptive stimuli, and innocuous vibrotactile stimuli, recorded using intracerebral electroencephalograpic activity in 7 epileptic patients (9 depth electrodes, 58 insular contacts). All four types of stimuli elicited consistent low-frequency phase-locked LFPs throughout the insula, possibly reflecting supramodal activity. The latencies of thermo-nociceptive and cool low-frequency phase-locked LFPs were shorter in the posterior insula compared to the anterior insula, suggesting a similar processing of thermal input initiating in the posterior insula, regardless of whether the input produces pain and regardless of thermal modality. In contrast, only thermo-nociceptive stimuli elicited an enhancement of insular GBOs, suggesting that these activities are not simply related to the activation of the spinothalamic system or to the conveyance of thermal information.

Holmes tremor: a delayed complication after resection of brainstem cavernomas

OBJECTIVE

In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs).

METHODS

After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT.

RESULTS

From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005).

CONCLUSIONS

Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.

Tonic, Burst, High-Density, and 10-kHz High-Frequency Spinal Cord Stimulation: Efficiency and Patients' Preferences in a Failed Back Surgery Syndrome Predominant Population. Review of Literature

BACKGROUND

Spinal cord stimulation (SCS) is a neuromodulation process to treat neuropathic pain, initially developed on tonic paresthesia-based stimulation. In the last decade, 3 major paresthesia-free SCSs have emerged. Several studies show their superiority over tonic stimulation.

OBJECTIVE

We summarize the data on SCS efficacy and patients' preferences.

METHODS

We selected studies from the last decade to clarify whether the different paresthesia-free SCSs are superior to tonic or not and for which SCS the patient has a preference. Study selection was focused on a failed back surgery syndrome predominant population.

RESULTS

SCS is an effective way to treat intractable neuropathic pain of the limbs and back, compared with conventional medical management and reoperation. Paresthesia-free SCSs as burst, high-density, and 10-kHz frequency are equal to tonic SCS in some studies and superior in most. Analysis of patients' preferences shows a clear trend toward paresthesia-free SCS.

CONCLUSIONS

Recent studies show superiority of paresthesia-free SCS compared with tonic SCS and those results are corroborated by analysis of patients' preferences. Taking these data into account should motivate physicians to opt for multimodal capable devices before implanting SCS.

Postoperative Infections Associated With Prolonged Spinal Cord Stimulation Trial Duration (PROMISE RCT)

Introduction

In the PROMISE study, a multinational randomized controlled trial (RCT) of the effectiveness of spinal cord stimulation (SCS) with multicolumn surgical leads as a treatment of low back pain, clinicians followed their usual practice. An early, unplanned safety analysis revealed that the infection rate in Belgium (5/23), where trial duration was a median 21.5 days, was significantly higher than the 1/64 rate observed in the other study countries (median 5.8 days, p < 0.01). This report reviews infections observed in the PROMISE study after study completion.

Materials and Methods

For all infections related to SCS, we used descriptive statistics and tests of independent variables to analyze potentially contributing factors (age, sex, coexisting medical conditions, tobacco use, lead type, and trial duration) between subjects with infections versus those without. Cumulative incidence curves were created using the Kaplan–Meier method and compared between the two strata using a log‐rank test.

Results

Among nine (5.2%) infections in 174 subjects trialed, the only significant contributing factor to infection was trial duration: median 21 days (range 3–56) for those with infection vs. six days (1–41) for those without (p = 0.001; Wilcoxon rank‐sum test). The cumulative incidence of infection for subjects trialed >10 days was 24.1% vs. 1.4% for subjects trialed ≤10 days (p < 0.001). After the protocol was amended to limit trial duration to 10 days, 14 infection‐free trials were performed in Belgium.

Conclusions

Although not part of the preplanned analysis, our observation supports the hypothesis of a cause‐effect relationship between trial duration and the risk of infection and the conclusion that prolonged SCS trials should be avoided.

Time to Diagnosis in Cushing's Syndrome: A Meta-Analysis Based on 5367 Patients

CONTEXT

Signs and symptoms of Cushing's syndrome (CS) overlap with common diseases, such as the metabolic syndrome, obesity, osteoporosis, and depression. Therefore, it can take years to finally diagnose CS, although early diagnosis is important for prevention of complications.

OBJECTIVE

The aim of this study was to assess the time span between first symptoms and diagnosis of CS in different populations to identify factors associated with an early diagnosis.

DATA SOURCES

A systematic literature search via PubMed was performed to identify studies reporting on time to diagnosis in CS. In addition, unpublished data from patients of our tertiary care center and 4 other centers were included.

STUDY SELECTION

Clinical studies reporting on the time to diagnosis of CS were eligible. Corresponding authors were contacted to obtain additional information relevant to the research question.

DATA EXTRACTION

Data were extracted from the text of the retrieved articles and from additional information provided by authors contacted successfully. From initially 3326 screened studies 44 were included.

DATA SYNTHESIS

Mean time to diagnosis for patients with CS was 34 months (ectopic CS: 14 months; adrenal CS: 30 months; and pituitary CS: 38 months; P < .001). No difference was found for gender, age (<18 and ≥18 years), and year of diagnosis (before and after 2000). Patients with pituitary CS had a longer time to diagnosis in Germany than elsewhere.

CONCLUSIONS

Time to diagnosis differs for subtypes of CS but not for gender and age. Time to diagnosis remains to be long and requires to be improved.

Bilateral Fornical Columns Infarction Secondary to an Arteriovenous Malformation Embolization

BACKGROUND

Three group of perforation branches are described coming out from the anterior communicating artery (AcoA): the hypothalamic branches, chiasmatic branches, and subcallosal artery (ScA). Bilateral anterior fornix infarction with sudden anterograde amnesia after ScA ischemic stroke has been previously described. Although only a few cases are reported in the literature, ScA occlusion has been well described for both noniatrogenic and iatrogenic causes. Several cases of iatrogenic injuries have been reported after AcoA aneurysm clipping or, less frequently, after embolization.

CASE DESCRIPTION

A 43-year-old man was admitted for a subarachnoid hemorrhage secondary to the rupture of a right high-flow anterior cerebral artery (ACA) aneurysm related to a right frontobasal arteriovenous malformation (AVM). The aneurysm was treated early by endovascular embolization. At discharge, the patient was Glasgow Outcome Scale score 1. Five months later, the AVM was treated endovascularly in 3 sessions. The last session was performed through a median branch of the right A2 segment of the ACA, allowing an 80% AVM exclusion. However, the patient woke up with anterograde memory impairment and confusion. Magnetic resonance imaging showed infarction of both anterior columns of the fornix. The clinical condition of the patient 3 years after stroke has improved.

CONCLUSIONS

Bilateral anterior fornix infarction leading to amnestic syndrome is encountered in ScA stroke. We report a rare case of bilateral anterior fornix infarction secondary to an AVM embolization supplied by the ACA, not an anatomic region that provides blood supply of the anterior columns of the fornix.

Middle cerebral artery fenestration: Thromboembolic and hemorrhagic complications

Cerebral artery fenestrations are rare anatomical variants usually detected incidentally on cross-sectional imaging or cerebral angiography. Although considered benign findings, many reports have described their association with vascular abnormalities such as aneurysms or arteriovenous malformations, and to a lesser extent with ischemic or hemorrhagic complications. We report a case of middle cerebral artery fenestration associated with subarachnoid hemorrhage and middle cerebral artery thrombosis. To our knowledge, there has been no prior report of middle cerebral artery fenestration with a similar presentation.

Tonic thermonociceptive stimulation selectively modulates ongoing neural oscillations in the human posterior insula: Evidence from intracerebral EEG

The human insula is an important target for spinothalamic input, but there is still no consensus on its role in pain perception and nociception. In this study, we show that the human insula exhibits activity preferential for sustained thermonociception. Using intracerebral EEG recorded from the insula of 8 patients (2 females) undergoing a presurgical evaluation of focal epilepsy (53 contacts: 27 anterior, 26 posterior), we "frequency-tagged" the insular activity elicited by sustained thermonociceptive and vibrotactile stimuli, by periodically modulating stimulation intensity at a fixed frequency of 0.2 Hz during 75 s. Both types of stimuli elicited an insular response at the frequency of stimulation (0.2 Hz) and its harmonics, whose magnitude was significantly greater in the posterior insula compared to the anterior insula. Compared to vibrotactile stimulation, thermonociceptive stimulation exerted a markedly greater 0.2 Hz modulation of ongoing theta-band (4-8 Hz) and alpha-band (8-12 Hz) oscillations. These modulations were also more prominent in the posterior insula compared to the anterior insula. The identification of oscillatory activities preferential for thermonociception could lead to new insights into the physiological mechanisms of nociception and pain perception in humans.

Granulomatous Reaction on a Double-Level Cervical Total Disc Arthroplasty

BACKGROUND

Cervical total disc arthroplasty (TDA), or cervical artificial disc replacement, is an alternative technique to anterior cervical discectomy and fusion for treatment of symptomatic degenerative cervical spine disease. The main goal of TDA is to maintain cervical motion and lower the risk of deterioration of adjacent levels. Granuloma formation on a cervical TDA is exceptional.

CASE DESCRIPTION

A 48-year-old woman with left cervicobrachialgia underwent a double-level TDA (M6-C Artificial Cervical Disc) on C5-C6 and C6-C7 at another hospital in 2010. Two years later, she reported a recurrence of cervicalgia, which was refractory to conservative treatment by rigid collar and analgesics. Cervical magnetic resonance imaging suggested a granulomatous formation on the C6-C7 prosthesis. She underwent removal of the C6-C7 prosthesis, which showed a rupture with nylon thread extrusion. An arthrodesis with plate was subsequently performed. Follow-up showed improvement of her clinical status. Histopathologic studies showed a giant cell granulomatous formation in contact with nylon threads described in hip, shoulder, and ankle arthroplasty. It has been described in 6 cases following lumbar TDA and 2 cases following cervical TDA.

CONCLUSIONS

We report a third case of granulomatous reaction on nylon thread extrusion after partial breakdown of a prosthesis for cervical TDA.

Gamma-Band Oscillations Preferential for Nociception can be Recorded in the Human Insula

Transient nociceptive stimuli elicit robust phase-locked local field potentials (LFPs) in the human insula. However, these responses are not preferential for nociception, as they are also elicited by transient non-nociceptive vibrotactile, auditory, and visual stimuli. Here, we investigated whether another feature of insular activity, namely gamma-band oscillations (GBOs), is preferentially observed in response to nociceptive stimuli. Although nociception-evoked GBOs have never been explored in the insula, previous scalp electroencephalography and magnetoencephalography studies suggest that nociceptive stimuli elicit GBOs in other areas such as the primary somatosensory and prefrontal cortices, and that this activity could be closely related to pain perception. Furthermore, tracing studies showed that the insula is a primary target of spinothalamic input. Using depth electrodes implanted in 9 patients investigated for epilepsy, we acquired insular responses to brief thermonociceptive stimuli and similarly arousing non-nociceptive vibrotactile, auditory, and visual stimuli (59 insular sites). As compared with non-nociceptive stimuli, nociceptive stimuli elicited a markedly stronger enhancement of GBOs (150-300 ms poststimulus) at all insular sites, suggesting that this feature of insular activity is preferential for thermonociception. Although this activity was also present in temporal and frontal regions, its magnitude was significantly greater in the insula as compared with these other regions.

Spinal intradural extramedullary cavernous hemangioma

Spinal intradural extramedullary cavernous hemangiomas are very rare. Mixed intensities on T1- andT2-weighted images due to repeated hemorrhages and poor to absent contrast-enhancement are the most common imaging features of the disease allowing accurate differentiation from the far more frequent meningiomas and schwannomas of similar location.

Outcome of Transsphenoidal Surgery for Cushing Disease: A Single-Center Experience over 20 Years

BACKGROUND

This study investigated the outcome of transsphenoidal surgery (TSS) for Cushing disease (CD) and the influence of our surgical strategy on remission rates and postoperative pituitary function.

PATIENTS AND METHODS

We retrospectively reviewed data from 71 patients with CD who underwent microscope navigation TSS (MN-TSS) in Saint-Luc Hospital between 1996 and 2017. True remission was defined as normal fasting cortisol level, normal 24-hour urinary free cortisol, or continued need for hydrocortisone replacement for 1 year after surgery.

RESULTS

Overall remission rate after 1 or repeated MN-TSS was 83%. Highest remission rate was found in patients with macroadenomas (92%). Successful first MN-TSS was correlated with a high final remission rate (95%), whereas failed first MN-TSS was correlated with a low final remission rate (36%). Although day 1 cortisol levels were significantly lower in patients with long-term remission, high levels were still observed in a few patients, especially those who had had CD for many years. We found a low rate of postoperative pituitary long-term hypofunction (9.7%).

CONCLUSIONS

MN-TSS is a safe and effective procedure to treat CD, allowing remission rates of 83%. One-year remission period after first surgery is correlated with a final remission rate of 95%. Although day 1 morning cortisol value is the most significant predictor for long-term remission, some patients with CD for many years may keep high postoperative cortisol levels and be in later remission, likely because of secondary adrenal hyperplasia. Our focused approach with microscope navigation resulted in low rates of postoperative pituitary hypofunction and kept a recurrence rate comparable to that in the literature.

Habituation of phase-locked local field potentials and gamma-band oscillations recorded from the human insula

Salient nociceptive and non-nociceptive stimuli elicit low-frequency local field potentials (LFPs) in the human insula. Nociceptive stimuli also elicit insular gamma-band oscillations (GBOs), possibly preferential for thermonociception, which have been suggested to reflect the intensity of perceived pain. To shed light on the functional significance of these two responses, we investigated whether they would be modulated by stimulation intensity and temporal expectation - two factors contributing to stimulus saliency. Insular activity was recorded from 8 depth electrodes (41 contacts) implanted in the left insula of 6 patients investigated for epilepsy. Thermonociceptive, vibrotactile, and auditory stimuli were delivered using two intensities. To investigate the effects of temporal expectation, the stimuli were delivered in trains of three identical stimuli (S1-S2-S3) separated by a constant 1-s interval. Stimulation intensity affected intensity of perception, the magnitude of low-frequency LFPs, and the magnitude of nociceptive GBOs. Stimulus repetition did not affect perception. In contrast, both low-frequency LFPs and nociceptive GBOs showed a marked habituation of the responses to S2 and S3 as compared to S1 and, hence, a dissociation with intensity of perception. Most importantly, although insular nociceptive GBOs appear to be preferential for thermonociception, they cannot be considered as a correlate of perceived pain.

Both invasiveness and proliferation criteria predict recurrence of non-functioning pituitary macroadenomas after surgery: a retrospective analysis of a monocentric cohort of 120 patients

INTRODUCTION

Additional robust criteria to predict early postoperative recurrence of non-functioning pituitary macroadenomas (NFMAs) are needed. Recently, a new classification of pituitary tumors has been proposed, which is based on both radiological and histological criteria and allows the grading into 5 groups of different potential aggressiveness. The aim of this study was to use this classification to further characterize predictive factors of recurrence in an independent series of NFMA.

CASES AND METHODS

120 patients operated for a NFMA were analyzed retrospectively. For each of them, the invasion of the cavernous and/or sphenoidal sinuses by the tumor was studied on the preoperative MRI and the proliferative character was based on precise histological and immunohistological examination.

RESULTS

26% (n = 31) of the adenomas were proliferative and 57% (n = 68) were invasive. The invasive lesions were larger (P < 0.001) and their removal was complete in only 82% of the cases. The distribution of NFMAs was as follows: 32% grade 1a, 11% (proliferative) grade 1b, 42% (invasive) grade 2a and 15% (proliferative and invasive) grade 2b. Their probability of recurrence at 5 years was 20, 39, 44 and 66%, respectively. A young age, the atypical character and the presence of postoperative residual tumor were all independent risk factors of recurrence (P < 0.025).

DISCUSSION

The new clinicopathological classification proves to be very useful in predicting the risk of recurrence of non-functioning pituitary macroadenomas after a first surgery. In particular, grade 2b lesions showed an overall likelihood of recurrence that was 8.6 times greater than those of grade 1a.