The lateral retrocanthal transorbital endoscopic approach to the middle fossa: cadaveric stepwise approach and review of quantitative cadaveric data

OBJECTIVE

The lateral retrocanthal transorbital endoscopic approach (LRCTEA) facilitates trajectory to the middle fossa, preserving the lateral canthal tendon and thus avoiding postoperative complications such as eyelid malposition. Here, the authors sought to define the surgical anatomy and technique of LRCTEA using a stepwise approach in cadaveric heads and offer an in-depth examination of existing quantitative data from cadaveric studies.

METHODS

The authors performed LRCTEA to the middle cranial fossa under neuronavigation in 7 cadaveric head specimens that underwent high-resolution (1-mm) CT scans preceding the dissections.

RESULTS

The LRCTEA provided access to middle fossa regions including the cavernous sinus, Meckel's cave, and medial temporal lobe. The trajectories and endpoints of the approach were confirmed using electromagnetic neuronavigation. A stepwise approach was delineated and recorded.

CONCLUSIONS

The authors' cadaveric study delineates the surgical anatomy and technique of the LRCTEA, providing a stepwise approach for its implementation. As these approaches continue to evolve, their development and refinement will play an important role in expanding the surgical options available to neurosurgeons, ultimately improving outcomes for patients with complex skull base pathologies. The LRCTEA presents a promising advancement in skull base surgery, particularly for accessing challenging middle fossa regions. However, surgeons must remain vigilant to potential complications, including transient diplopia, orbital hematoma, or damage to the optic apparatus.

Rate of pachymeningeal failure following adjuvant WBRT vs SRS in patients with brain metastases

Background

Stereotactic radiosurgery (SRS) has supplanted whole brain radiotherapy (WBRT) as standard-of-care adjuvant treatment following surgery for brain metastasis (BrM). Concomitant with the adoption of adjuvant SRS, a new pattern of failure termed "Pachymeningeal failure" (PMF) has emerged.

Methods

We reviewed a prospective registry of 264 BrM patients; 145 and 119 were treated adjuvantly with WBRT and SRS, respectively. The Cox proportional hazards model was used to identify variables correlating to outcomes. Outcomes were calculated using the cumulative incidence (CI) method. Univariate (UVA) and multivariate analyses (MVA) were done to identify factors associated with PMF.

Results

CI of PMF was 2 % and 18 % at 12 months, and 2 % and 23 % at 24 months for WRBT and SRS, respectively (p < 0.001). The CI of classic leptomeningeal disease (LMD) was 3 % and 4 % at 12 months, and 6 % and 6 % at 24 months for WBRT and SRS, respectively (P = 0.67). On UVA, adjuvant SRS [HR 9.75 (3.43-27.68) (P < 0.001)]; preoperative dural contact (PDC) [HR 6.78 (1.64-28.10) (P = 0.008)]; GPA score [HR 1.64 (1.11-2.42) (P = 0.012)]; and lung EGFR/ALK status [HR 3.11 (1.02-9.45) (P = 0.045)]; were associated with PMF risk. On MVA, adjuvant SRS [HR 8.15 (2.69-24.7) (P < 0.001)]; and PDC [HR 6.28 (1.51-26.1) (P = 0.012)] remained associated with PMF.

Conclusions

Preoperative dural contact and adjuvant SRS instead of adjuvant WBRT were associated with an increased risk of PMF. Strategies to improve pachymeningeal radiation coverage to sterilize at risk pachymeninges should be investigated.

Endoscopic endonasal surgery for prolactinomas: prognostic factors for disease control and management of persistent disease

Only a limited number of studies have focused on the results of the Endoscopic Endonasal Approach (EEA) for treatment of prolactinomas. We sought to assess the effectiveness of EEA for prolactinoma surgery, identify factors for disease remission, and present our approach for the management of persistent disease. Forty-seven prolactinomas operated over 10 years, with a mean follow-up of 59.9 months, were included. The primary endpoints were early disease remission and remission at last follow-up. Resistance/intolerance to DA were surgical indications in 76.7%. Disease remission was achieved in 80% of microprolactinomas and 100% of microprolactinomas enclosed by the pituitary. Early disease remission was correlated with female gender (p=0.03), lower preoperative PRL levels (p=0.014), microadenoma (p=0.001), lack of radiological hemorrhage (p=0.001), absence of cavernous sinus (CS) invasion (p<0.001), and extent of resection (EOR) (p<0.001). Persistent disease was reported in 48.9% of patients, with 47% of them achieving remission at last follow-up with DA therapy alone. Repeat EEA and/or radiotherapy were utilized in 6 patients, with 66.7% achieving remission. Last follow-up remission was achieved in 76.6%, with symptomatic improvement in 95.8%. Factors predicting last follow-up remission were no previous operation (p=0.001), absence of CS invasion (p=0.01), and EOR (p<0.001). Surgery is effective for disease control in microprolactinomas. In giant and invasive tumors, it may significantly reduce the tumor volume. A multidisciplinary approach may lead to long-term disease control in three-quarters of patients, with symptomatic improvement in an even greater proportion.

The anatomy of the four streams of the prefrontal cortex. Preliminary evidence from a population based high definition tractography study

The model of the four streams of the prefrontal cortex proposes 4 streams of information: motor through Brodmann area (BA) 8, emotion through BA 9, memory through BA 10, and emotional-related sensory through BA 11. Although there is a surge of functional data supporting these 4 streams within the PFC, the structural connectivity underlying these neural networks has not been fully clarified. Here we perform population-based high-definition tractography using an averaged template generated from data of 1,065 human healthy subjects acquired from the Human Connectome Project to further elucidate the structural organization of these regions. We report the structural connectivity of BA 8 with BA 6, BA 9 with the insula, BA 10 with the hippocampus, BA 11 with the temporal pole, and BA 11 with the amygdala. The 4 streams of the prefrontal cortex are subserved by a structural neural network encompassing fibers of the anterior part of the superior longitudinal fasciculus-I and II, corona radiata, cingulum, frontal aslant tract, and uncinate fasciculus. The identified neural network of the four streams of the PFC will allow the comprehensive analysis of these networks in normal and pathological brain function.

Radiographic predictors of occult intracranial involvement in olfactory neuroblastoma patients

BACKGROUND

Traditional management of olfactory neuroblastoma (ONB) includes margin-negative resection with removal of cribriform plate, dura, and olfactory bulb, regardless of intracranial disease. This approach may be overtreating certain patients. Our investigation examines risk factors associated with occult intracranial disease to optimize therapeutic outcomes.

METHODS

This retrospective, multi-institutional cohort study examined clinical covariates associated with occult intracranial involvement. Patient demographics, staging, Hyam's grade, and pathologic involvement of dura, olfactory bulb/tract, and brain were collected. Diagnostic imaging was reviewed. Positive and negative predictive value (NPV) were estimated along with effect size estimates. Cox hazard regression examined associations with overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 224 subjects with new diagnoses of ONB (2005-2021) were identified. Skull base bone involvement on computed tomography (CT) had the highest NPV for pathologic dura (88.0%), olfactory bulb (88%), and brain involvement (97.3%). Hyam's grade category was significantly associated with dural involvement (φC  = 0.26; 95% confidence interval [CI]: 0.16, 0.42). Subjects without radiologic skull base involvement (n = 66) had pathologic positivity of 12.1%. Within this subgroup, Hyam's grade was clinically significant for dural positivity (φ = 0.34; 95% CI: -0.12, 0.71) with 28.6% involvement in high grade tumors. Neither clinical nor pathologic positivity of intracranial structures were associated with significantly different OS or DFS.

CONCLUSIONS

Both CT and magnetic resonance imaging (MRI) had reasonably good NPV for involvement of dura and olfactory bulb. Higher Hyam's grade was associated with dural involvement. Patients with low-grade tumors not involving the skull base may be suitable for avoiding skull base resection; however, further investigation is warranted.

Pachymeningeal disease: a systematic review and metanalysis

BACKGROUND

Pachymeningeal disease (PMD) is a newly recognized pattern of brain metastasis (BrM) failure that specifically occurs following surgery with adjuvant stereotactic radiosurgery (SRS) and has unique prognostic implications relative to leptomeningeal disease (LMD). Here, we report its prevalence, prognostic implications, and associated risk factors.

METHODS

A literature search was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses on PUBMED and Cochrane from January 2000 to June 2023.

RESULTS

We identified 12 studies that included a total of 3992 BrM patients, 659 (16.5%) of whom developed meningeal disease (MD) following surgery plus adjuvant SRS, including either PMD or LMD. The mean prevalence of MD across studies was 20.9% (7.9-38.0%), with PMD accounting for 54.6% of this prevalence and LMD comprising the remaining 45.4%. Mean of the median overall survivals following diagnosis of PMD and LMD was 10.6 months and 3.7 months p = 0.007, respectively, a significant difference. Only 2 risk factors for PMD were reported in ≥ 2 studies and also identified as statistically significant per our meta-analysis: infratentorial location and controlled systemic disease status.

CONCLUSION

While PMD has a superior prognosis to LMD, it is nevertheless a critical oncologic event associated with significant mortality and remains poorly recognized. PMD is predominantly observed in patients with controlled systemic disease status and infratentorial location. Future treatment strategies should focus on reducing surgical seeding and sterilizing surgical cavities.

Multicenter Survival Analysis and Application of an Olfactory Neuroblastoma Staging Modification Incorporating Hyams Grade

Importance

Current olfactory neuroblastoma (ONB) staging systems inadequately delineate locally advanced tumors, do not incorporate tumor grade, and poorly estimate survival and recurrence.

Objective

The primary aims of this study were to (1) examine the clinical covariates associated with survival and recurrence of ONB in a modern-era multicenter cohort and (2) incorporate Hyams tumor grade into existing staging systems to assess its ability to estimate survival and recurrence.

Design, Setting, and Participants

This retrospective, multicenter, case-control study included patients with ONB who underwent treatment between January 1, 2005, and December 31, 2021, at 9 North American academic medical centers.

Intervention

Standard-of-care ONB treatment.

Main Outcome and Measures

The main outcomes were overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) as C statistics for model prediction.

Results

A total of 256 patients with ONB (mean [SD] age, 52.0 [15.6] years; 115 female [44.9%]; 141 male [55.1%]) were included. The 5-year rate for OS was 83.5% (95% CI, 78.3%-89.1%); for DFS, 70.8% (95% CI, 64.3%-78.0%); and for DSS, 94.1% (95% CI, 90.5%-97.8%). On multivariable analysis, age, American Joint Committee on Cancer (AJCC) stage, involvement of bilateral maxillary sinuses, and positive margins were associated with OS. Only AJCC stage was associated with DFS. Only N stage was associated with DSS. When assessing the ability of staging systems to estimate OS, the best-performing model was the novel modification of the Dulguerov system (C statistic, 0.66; 95% CI, 0.59-0.76), and the Kadish system performed most poorly (C statistic, 0.57; 95% CI, 0.50-0.63). Regarding estimation of DFS, the modified Kadish system performed most poorly (C statistic, 0.55; 95% CI, 0.51-0.66), while the novel modification of the AJCC system performed the best (C statistic, 0.70; 95% CI, 0.66-0.80). Regarding estimation of DSS, the modified Kadish system was the best-performing model (C statistic, 0.79; 95% CI, 0.70-0.94), and the unmodified Kadish performed the worst (C statistic, 0.56; 95% CI, 0.51-0.68). The ability for novel ONB staging systems to estimate disease progression across stages was also assessed. In the novel Kadish staging system, patients with stage VI disease were approximately 7 times as likely to experience disease progression as patients with stage I disease (hazard ratio [HR], 6.84; 95% CI, 1.60-29.20). Results were similar for the novel modified Kadish system (HR, 8.99; 95% CI, 1.62-49.85) and the novel Dulguerov system (HR, 6.86; 95% CI, 2.74-17.18).

Conclusions and Relevance

The study findings indicate that 5-year OS for ONB is favorable and that incorporation of Hyams grade into traditional ONB staging systems is associated with improved estimation of disease progression.

Anatomical and surgical characteristics correlate with pachymeningeal failure in patients with brain metastases after neurosurgical resection and adjuvant stereotactic radiosurgery

PURPOSE

Neurosurgery (NS) is an essential modality for large brain metastases (BM). Postoperative stereotactic radiosurgery (SRS) is the standard of care adjuvant treatment. Pachymeningeal failure (PMF) is a newly described entity, distinct from classical leptomeningeal failure (LMF), that is uniquely observed in postoperative patients treated with adjuvant SRS. We sought to identify risk factors for PMF in patients treated with NS + SRS.

METHODS

From a prospective registry (2009 to 2021), we identified all patients treated with NS + SRS. Clinical, imaging, pathological, and treatment factors were analyzed. PMF incidence was evaluated using a competing risks model.

RESULTS

144 Patients were identified. The median age was 62 (23-90). PMF occurred in 21.5% (31/144). Female gender [Hazard Ratio (HR) 2.65, p = 0.013], higher Graded Prognostic Assessment (GPA) index (HR 2.4, p < 0.001), absence of prior radiation therapy (HR N/A, p = 0.018), controlled extracranial disease (CED) (HR 3.46, p = 0.0038), and pia/dura contact (PDC) (HR 3.30, p = 0.0053) were associated with increased risk for PMF on univariate analysis. In patients with PDC, wider target volumes correlated with reduced risk of PMF. Multivariate analysis indicated PDC (HR 3.51, p = 0.0053), piecemeal resection (HR 2.38, p = 0.027), and CED (HR 3.97, p = 0.0016) independently correlated with PMF risk. PMF correlated with reduced OS (HR 2.90, p < 0.001) at a lower rate compared to LMF (HR 10.15, p < 0.001).

CONCLUSION

PMF correlates with tumor PDC and piecemeal resection in patients treated with NS + SRS. For unclear reasons, it is also associated with CED. In tumors with PDC, wider dural radiotherapy coverage was associated with a lower risk of PMF.

Investigation of neurophysiologic and functional connectivity changes following glioma resection using magnetoencephalography

Background

In patients with glioma, clinical manifestations of neural network disruption include behavioral changes, cognitive decline, and seizures. However, the extent of network recovery following surgery remains unclear. The aim of this study was to characterize the neurophysiologic and functional connectivity changes following glioma surgery using magnetoencephalography (MEG).

Methods

Ten patients with newly diagnosed intra-axial brain tumors undergoing surgical resection were enrolled in the study and completed at least two MEG recordings (pre-operative and immediate post-operative). An additional post-operative recording 6-8 weeks following surgery was obtained for six patients. Resting-state MEG recordings from 28 healthy controls were used for network-based comparisons. MEG data processing involved artifact suppression, high-pass filtering, and source localization. Functional connectivity between parcellated brain regions was estimated using coherence values from 116 virtual channels. Statistical analysis involved standard parametric tests.

Results

Distinct alterations in spectral power following tumor resection were observed, with at least three frequency bands affected across all study subjects. Tumor location-related changes were observed in specific frequency bands unique to each patient. Recovery of regional functional connectivity occurred following glioma resection, as determined by local coherence normalization. Changes in inter-regional functional connectivity were mapped across the brain, with comparable changes in low to mid gamma-associated functional connectivity noted in four patients.

Conclusion

Our findings provide a framework for future studies to examine other network changes in glioma patients. We demonstrate an intrinsic capacity for neural network regeneration in the post-operative setting. Further work should be aimed at correlating neurophysiologic changes with individual patients' clinical outcomes.

Effectiveness of pharmacologic interventions for prevention of cerebral hyperperfusion syndrome following bypass surgery

BACKGROUND

Cerebral hyperperfusion syndrome (CHS) following bypass surgery is a major cause of neurological morbidity and mortality. However, data regarding its prevention have not been assorted until date.

OBJECTIVE

The objective of this study was to review the literature and evaluate whether any conclusion can be drawn regarding the effectiveness of any measure on preventing bypass-related CHS.

METHODS

We systematically reviewed PubMed and Cochrane Library from September 2008 to September 2018 to collect data regarding the effectiveness of pharmacologic interventions on the refers to pretreatment (PRE) of bypass-related CHS. We categorized interventions regarding their class of drugs and their combinations and calculated overall pooled estimates of proportions of CHS development through random-effects meta-analysis of proportions.

RESULTS

Our search yielded 649 studies, of which 23 fulfilled inclusion criteria. Meta-analysis included 23 studies/2,041 cases. In Group A (blood pressure [BP] control), 202 out of 1,174 pretreated cases developed CHS (23.3% pooled estimate; 95% confidence interval [CI]: 9.9-39.4), Group B (BP control + free radical scavenger [FRS]) 10/263 (0.3%; 95% CI: 0.0-14.1), Group C (BP control + antiplatelet) 22/204 (10.3%; 95% CI: 5.1-16.7), and Group D (BP control + postoperative sedation) 29/400 (6.8%; 95% CI: 4.4-9.6)].

CONCLUSIONS

BP control alone has not been proven effective in preventing CHS. However, BP control along with either a FRS or an antiplatelet agent or postoperative sedation seems to reduce the incidence of CHS.

LITTing up Gliomas- Is the future Bright?

Background

Laser interstitial thermal therapy (LITT) represents an attractive therapeutic strategy for several intracranial pathologies; however, there is a paucity of literature regarding its efficacy for the treatment of gliomas.

Methods

MEDLINE, EMBASE, Scopus, and Web of Science were searched from inception until March 19, 2021. Studies specifically relating to the use of LITT in treatment of glioma were eligible for inclusion. A meta-analysis of means was performed to assess the progression-free survival (PFS) and overall survival (OS) following LITT and descriptive statistics relating to patients undergoing LITT were collated and a meta-analysis of proportions was also performed to assess the rate of complications.

Results

In total, 17 studies were included for the meta-analysis, comprising 401 patients with 408 gliomas of which 88 of 306 (28.8%) were grade 1 or 2 and 218 of 306 (71.2%) were grade 3 or 4. Of these, 256 of 408 (62.8%) were primary presentation and 152 of 408 (37.2%) were recurrent. The pooled mean OS was 13.58 months (95% confidence interval [CI] 9.77–17.39) and the PFS was 4.96 months (95% CI 4.19–5.72). The OS and PFS of recurrent glioblastoma were 12.4 months (95% CI 9.61–16.18) and 4.84 months (95% CI 0.23–9.45), respectively. Complications occurred in 114 of 411 (24%; 95% CI 14–41), of which 44 (11%) were transient deficits.

Conclusions

There is an increasing body of evidence demonstrating the use of LITT in the surgical management of deep-seated gliomas in patients of poor performance status. However, further studies are required to interrogate the clinical effectiveness of LITT in the setting of gliomas as well as assessing the survival benefit versus standard treatment alone.

MMAP-09 CHARACTERISTICS CORRELATING WITH SURVIVAL IN PATIENTS TREATED FOR LARGE BRAIN METASTASES

BACKGROUND

We aimed to identify factors predicting survival following treatment to large (>4cc) BrM.

METHODS

From a prospective registry database, we identified 364 adult patients treated for brain metastases (BrM) or surgical cavities larger than >4 cc: 127 and 237 treated with surgery plus stereotactic radiosurgery (S+SRS) and SRS alone, respectively. We compared the 2 treatment arms using propensity score-matched (PSMA) and multivariate analyses (MVA). P values <0.05 were considered statistically significant.

RESULTS

Median target volume was 6.6cc (4-36.9cc) for intact BrM and 15cc (4-54) for cavities. Median OS was 19 and 12 months for the S+SRS and SRS groups, respectively [HR 1.73 (1.35-2.22) (P<0.001)]. On UVA, number of BrM [HR 1.13 (1.06-1.22) (P<0.001)], ECOG 3-4 [HR 2.78 (1.73-4.46) (P<0.001)], and extracranial disease (ECD) at BrM treatment [HR 1.82 (1.37,2.40) (P<0.001)], correlated inversely with OS. GPA [HR 0.61 (0.52,0.70) (P<0.001)] and receipt of systemic therapy after BrM treatment[HR 0.58 (0.45-0.75) (P<0.001)] correlated to improved OS. On MVA, S+SRS [HR 1.81 (1.19,2.74) (P<0.0054)], reduced target volume [HR 1.03 (1.01,1.06) (P<0.0042)], and receipt of immune/targeted therapy [HR 0.68 (0.50,0.93) (P<0.015)] correlated with OS. PSMA comparing the treatment arms matched by ECD, number of BrM, ECOG, and SRS target volume, demonstrated that treatment arm remained correlated to OS [HR 1.62 (1.20-2.19) (P=0.0015)]. The cumulative incidence (CI) of LF requiring surgical resection at 12 months was 3% versus 7% for S+SRS and SRS groups, respectively [(HR 2.04 (0.89-4.69) (P =0.091)]. CI of PMD at 12 months was 16% versus 0% for S+SRS and SRS groups, respectively.

CONCLUSION

Reduced SRS target volume, treatment with systemic therapy following BrM treatment, and surgical resection prior to SRS correlate with survival in patients with large BrM. PMSA supports the hypothesis that surgery prior to SRS improves survival in patients with large BrM.

CLRM-20 IDENTIFYING RISK FACTORS AND ANALYZING SURVIVAL FOLLOWING PACHYMENINGEAL FAILURE

OBJECTIVE

Neurosurgery (NS) is an essential modality for large brain metastases (BM). As an adjuvant treatment, stereotactic radiosurgery (SRS) reduces neurocognitive toxicity without affecting post-treatment overall survival (OS) compared to whole brain radiation therapy. Pachymeningeal failure (PMF) beyond the SRS field is a relatively newly described entity, distinct from classical leptomeningeal failure (LMF), and unique to postoperative patients treated with adjuvant SRS. We sought to identify risk factors for PMF in patients treated with NS+SRS.

METHODS

We reviewed a prospective registry (2009 to 2020) and identified all patients treated with NS+SRS. Clinical, radiological, pathological and treatment factors were analyzed. PMF incidence was evaluated using a competing risks model and differences between cohorts were measured using the Fine-Gray method.

RESULTS

144 Patients were identified. Median age was 62 (23-90). PMF occurred in 22.2% (32/144) patients). Univariate analysis indicated female gender (HR 2.65, p=0.013), higher GPA status (HR 2.4, p<0.001), absence of prior radiation therapy (HR N/A, p=0.018), controlled extracranial disease (CED) (HR 3.46, p=0.0038), and contact with the pia/dura (HR 3.30, p=0.0053) as risk factors for PMF. Piecemeal (vs En-bloc) resection also trended towards correlation (HR 2.07, p=0.054). Multivariate Analysis identified contact with pia/dura (HR 3.51, p=0.0053), piecemeal resection (HR 2.38, p=0.027), and CED (HR 3.97, p=0.0016) as significant correlates to PMF. PMF correlated with reduced OS (HR 2.90, p<0.001) but was improved compared to patients who developed LMF (HR 10.15, p= p<0.001).

CONCLUSIONS

PMF is an underrecognized phenomenon that correlates with pre-operative pia/dura contact and piecemeal resection in patients treated with NS+SRS for BM. While less morbid than LMF, it is a critical event that deserves increased vigilance and analysis.

LOCL-13 SURGICAL RESECTION PLUS STEREOTACTIC RADIOSURGERY (SRS) VERSUS SRS ALONE FOR LARGE POSTERIOR FOSSA BRAIN METASTASES: OUTCOMES AND FACTORS GUIDING THE DECISION OF TREATMENT MODALITY

INTRODUCTION

Approximately 20% of brain metastases (BM) occur in the posterior fossa (PF). However, the criteria to treat large PF BM with surgery (S) followed by stereotactic radiosurgery (SRS) or SRS alone are still unclear. We aim to identify parameters that can help in the decision of treating PF BM with S+SRS or SRS and to compare outcomes between the two groups.

METHODOLOGY

We reviewed a prospective registry database (2009 to 2020) and identified all patients with PF BM (≥4cc in volume) treated with SRS or S+SRS. Clinical and radiological, parameters were analyzed. We examined two endpoints: Overall Survival (OS) and Local Failure (LF).

RESULTS

64 patients were identified; 30 were treated with S+ SRS and 34 with SRS. Gait imbalance and Intracranial pressure symptoms were significantly different between the groups; 97% and 80% for S+SRS vs 47% and 35% for SRS, respectively. Radiologically, there were significant differences in the mean volume of the lesions [6.7 cm3 in SRS vs 29.8cm3 in S+SRS cohort] (p&lt;0.001), compression of the IV ventricle (47% in SRS vs 96% in S+SRS cohort, (p&lt;0.001)) and hydrocephalus (0% in SRS vs 29% in S+SRS cohort, (p&lt;0.001)). One surgical patient required salvage SRS and two SRS patients required salvage S. Patients with S+SRS (HR 0.35, p&lt;0.001) and higher GPA scores (HR 0.62, p=0.007) correlated with better OS. There was no significant difference in rates of LF between the 2 groups.

CONCLUSIONS

Patients treated with S+SRS were more likely to be symptomatic, have larger tumors, and have compression of the IV ventricle with hydrocephalus. Non-symptomatic patients with moderately sized lesions were safely managed with SRS. S+SRS treatment and higher GPA were associated with improved OS.

Multiplicity does not significantly affect outcomes in brain metastasis patients treated with surgery

Background

Brain metastasis quantity may be a negative prognostic factor for patients requiring resection of at least one lesion.

Methods

We retrospectively reviewed patients who underwent surgical resection of brain metastases from July 2018 to June 2019 at our institution, and examined outcomes including overall survival (OS), progression free survival (PFS) and rates of local failure (LF). Patients were grouped according to the number of metastases at the time of surgery (single vs multiple).

Results

We identified 130 patients who underwent surgical resection as the initial treatment modality. At the time of surgery, 87 patients had only one lesion (control) and 43 had multiple (&gt;1). Two-year OS for the entire cohort was 46%, with equal rates in both the multiple metastases group and the control group (p=0.335). 2-year PFS was 27%; 21% in the multiple metastases group and 31% in the control group (p=0.766). The rate of LF at 2-years was 32%, with equal rates in both the multiple lesion group and control group (p=0.889). On univariate analysis, multiplicity was not significantly correlated to OS (HR=0.80, 95% CI: 0.51-1.26, p=0.336), PFS (HR=1.06, 95% CI: 0.71-1.59, p=0.766) or LF (HR=1.06, 95% CI: 0.57-1.97, p=0.840). Multivariate analysis revealed preoperative tumor volume of the resected lesion to be the single correlate for OS (p=0.0032) and PFS (p=0.0081).

Conclusions

Having more than one metastasis does not negatively impact outcomes in patients treated with surgery. In carefully selected patients, especially those with large tumors, surgery should be considered regardless of the total number of lesions.

Defining the limits and indications of the Draf III endoscopic approach to the lateral frontal sinus and maximizing visualization and maneuverability: a cadaveric and radiological study

PURPOSE

The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure.

METHODS

Seven cadaver heads were imaged with computed tomography scan. The distance from midline to the medial orbital wall (MOWD), midline to the lateral end of the frontal sinus (MLD), the sum of MLDs (SMLD), interorbital distance (IOD) and the shortest anteroposterior distance of the frontal recess (APD) were utilized. The ratios MLD/MOWD, and SMLD/IOD were calculated. The same distances were measured on 41 CT scans. Orbital transposition (OT) and partial resection of the piriform aperture (PAR) were performed; the visualization and reach were assessed. The angle of insertion was measured before and after the modifications.

RESULTS

Only the ratio MLD/MOWD was consistently predictive of access to the lateral, superior and posterior wall of the frontal sinus. Following the modifications, a visualization of 100% laterally was achieved with the 30- and 45 degree endoscopes and every lateral recess could be reached with the 70 degree suction. A mean increase of the angle of insertion of 25.3 and 59.6% was recorded after OT and PAR, respectively.

CONCLUSIONS

IOD rather than APD defines the limits of the Draf III approach to the lateral frontal sinus and MLD/MOWD ratio can serve as a useful preoperative tool. Along to the already described OT, PAR increases visualization and reach of the lateral frontal sinus.

Pneumomediastinum as a Complication of Oral and Maxillofacial Injuries: Report of 3 Cases and a 50-Year Systematic Review of Case Reports

Objectives

Pneumomediastinum (PM) secondary to oromaxillofacial trauma (OMF) is a rare but well-described complication/pathologic finding. The aim of this study was twofold: first, to report our experience in treatment of maxillofacial trauma patients with PM, and second, to review the literature regarding the clinical features, severity, course, and management of the aforementioned complication.

Material and methods

We retrospectively reviewed the medical records and charts of patients who suffered from maxillofacial trauma and treated in our hospital between September 1, 2013 and September 31, 2017. The inclusion criteria were patients with radiologically confirmed PM. In addition, the electronic databases PubMed, Scopus, and Science Direct were queried for articles reporting PM cases secondary to OMF injuries and published in English, French, and German language.

Results

Three cases of PM out of 3,514 cases of craniomaxillofacial trauma were found; there were 3 male patients who presented in our emergency department with the chief complaint of cervicofacial swelling. Literature search isolated 58 selected articles and 63 cases were assessed in total; posttraumatic repeated blowing of nose was proved as most frequent triggering factor among them. Furthermore, the outcomes of review showed that thoracic pain, respiratory distress, and swallowing difficulties were not frequently reported in patients with ME due to facial trauma.

Conclusions

Both our experience and the results of systematic literature review indicated that patients with PM due to OMF injuries present mild clinical course. If properly managed, this specific pathologic condition may have no further complications or relative comorbidities. The exact etiology and mechanism of PM in the context of maxillofacial injuries always needs to be identified. Radiographic, laboratory, and endoscopic examinations should be applied to rule out the more serious and frequently diagnosed aerodigestive, thoracic, and abdominal causes of PM.

Endoscopic treatment of sellar arachnoid cysts via a simple cyst-opening technique: Long-term outcomes from a single center

BACKGROUND

Sellar arachnoid cysts (SACs) are rare lesions that require treatment only if symptomatic. The endoscopic endonasal approach has been widely utilized. Despite their simple cystic appearance and the straight-forward surgical intervention there are important associated risks, with CSF leak being the prevalent one.

METHODS

A retrospective analysis of patients with pathologically confirmed SAC between January 2006 and December 2019 was conducted. A homogeneous simple cyst-opening technique and skull base reconstruction utilizing nasoseptal flaps was used.

RESULTS

Ten patients were identified (7 female and 3 male, median age was 54.5 years, range 20-77); 8 had newly diagnosed SACs whereas 2 recurrences from a previously microsurgically fenestrated SAC. Eight patients presented with visual symptoms (VS), 1 with VS and fatigue, and 1 with headaches. Neuro-ophthalmological and endocrinological assessments revealed visual field (VF) deficits in 6, visual acuity (VA) decline in 5 and hypopituitarism in 2 patients. Median calculated volume was 1.71 ml (range 0.27 - 2.54 ml). Postoperatively, no CSF leak and no further surgical complications were noted. VF improved in 4/6 while VA improved in 4/5 patients. Anterior pituitary function improved in 1, worsened in 1 and remained stable in 8 patients. One patient suffered diabetes insipidus. One recurrence was recorded 54 months postoperatively.

CONCLUSION

SACs can be effectively treated with a simple cyst-opening technique. The routine use of nasoseptal flaps significantly reduces the risk of CSF leak without compromising nasal quality of life in the long-term or mandating additional incisions. A long-term follow-up is important to monitor for late recurrences.

OUP accepted manuscript

BACKGROUND

We sought to identify variates correlating with overall survival (OS) in patients treated with surgery (S) plus adjuvant stereotactic radiosurgery (SRS) versus definitive SRS for large (&gt;4 cc) brain metastases (BrM).

METHODS

We used univariate (UVA) and multivariate analyses (MVA) to identify survival correlates among eligible patients identified from a prospective registry and compared definitive SRS to S+ adjuvant SRS cohorts using propensity score-matched analysis (PSMA). Secondary outcomes were measured using the cumulative incidence (CI) method.

RESULTS

We identified 364 patients; 127 and 237 were treated with S+SRS and definitive SRS, respectively. On UVA, SRS alone [HR1.73 (1.35,2.22) P &lt; .001), BrM quantity [HR 1.13 (1.06-1.22) (P &lt; .001)]; performance status (PS) [HR 2.78 (1.73-4.46) (P &lt; .001)]; extracranial disease (ECD) [HR 1.82 (1.37,2.40) (P &lt; .001)]; and receipt of systemic treatment after BrM therapy, [HR 0.58 (0.46-073) (P &lt; .001)] correlated with OS. On MVA, SRS alone [HR 1.81 (1.19,2.74) (P &lt; .0054)], SRS target volume [HR 1.03 (1.01,1.06) (P &lt; .0042)], and receipt of systemic treatment [HR 0.68 (0.50,0.93) (P &lt; .015)] correlated with OS. When PSMA was used to balance ECD, BrM quantity, PS, and SRS target volume, SRS alone remained correlated with worsened OS [HR 1.62 (1.20-2.19) (P = 0.0015)]. CI of local failure requiring resection at 12 months was 3% versus 7% for S+SRS and SRS cohorts, respectively [(HR 2.04 (0.89-4.69) (P = .091)]. CI of pachymeningeal failure at 12 months was 16% versus 0% for S+SRS and SRS.

CONCLUSION

SRS target volume, receipt of systemic therapies, and treatment with S+SRS instead of definitive SRS correlated with improved survival in patients with large BrM.

Introducing the Posterior Condylar Emissary Vein as an Effective Surgical Landmark for Optimizing the Standard Retrosigmoid Approach: An Anatomo-Imaging Study

OBJECTIVE

There is a lack of definite anatomical landmarks for the inferior extension of the standard retrosigmoid approach. In this study, we evaluated whether the posterior condylar emissary vein (PCEV) can be used as an intraoperative landmark for optimizing the surgical corridor.

METHODS

We performed the standard retrosigmoid approach on 5 formalin-fixed and latex-injected cadaveric specimens and measured the distance between the PCEV near its bony canal and the vertebral artery (VA). In addition, vascular reconstructions of thin-sliced preoperative computed tomography (CT) scans were studied in 40 patients and the relationship between these 2 vessels was evaluated. An illustrative case is also included.

RESULTS

The PCEV was consistently identified on both sides of cadaveric specimens and in 87.5% and 82.5% of the left and right sides of the included CT scans, respectively. The average distance between the part of the PCEV near its osseous canal and the VA was measured to be between 8.4 mm and 8.6 mm in the specimens and between 9.2 mm and 9.3 mm in the CT scans. This distance offers a safe and effective plane of dissection during the standard retrosigmoid approach and allows easy access to the foramen magnum.

CONCLUSIONS

The PCEV near its bony canal proved to be an easy, straightforward, safe, and effective operative landmark with which the surgeon can extend the soft tissue dissection and bony exposure towards the foramen magnum. This maneuver provides ample access to the cisterna magna for cerebrospinal fluid drainage and increases visibility and surgical maneuverability to the entire cerebellopontine angle.

Dissociation between visuospatial neglect assessment tasks and its neuroanatomical substrates: a case report

Visuospatial neglect possesses significant heterogeneity in clinical features and neuroanatomical substrates. Behavioral dissociations on different neglect tasks have been reported in the past, and the investigation of their respective anatomical correlates at cortical and, to a lesser degree, subcortical levels has been attempted in stroke studies. We report a patient with a neoplasm occupying the right ventral post-central gyrus and anterior supramarginal gyrus. The patient was admitted preoperatively with dissociation on the performance of neglect tasks, showing clinical deficits in the line bisection task and clock drawing, but not on the cancelation task. The patient underwent an awake craniotomy for tumor excision. Intraoperative visuospatial mapping was employed by applying direct electrical stimulation (DES) to the supramarginal gyrus and the ventral branch of the superior longitudinal fasciculus (SLF III) during the line bisection task. According to our findings, DES was ineffective at the cortical level, but it induced strong rightward bias when applied subcortically at the SLF III. By combining our preoperative and intraoperative anatomical and clinical data, we suggest that the posterior part of the SLF III might have a distinct role in the perceptual component of neglect. Our findings are discussed within the context of previous literature supporting the notion that particular behavioral features of spatial neglect are mediated by different white-matter connections.

MLTI-06. Surgical resection plus stereotactic radiosurgery versus SRS alone for large brain metastases: a comparative study

Purpose

Large brain metastases (BRM) are challenging to manage. Therapeutic options include Stereotactic Radiosurgery (SRS) or surgery (S) with adjuvant SRS. We sought to compare overall survival (OS), radionecrosis (RN), local failure (LF), pachymeningeal (PMD) and leptomeningeal (LMD) disease in patients treated with SRS vs. S+SRS.

Methods

We reviewed a prospective registry database from 2009 to 2020 and identified all patients with BRM (≥4cc in volume) treated with SRS or S+SRS. WBRT or SRS re-targeting the index lesion were censoring events. Survival percentages were calculated using the Kaplan-Meier method. Differences between groups were tested using the Cox proportional hazards model.

Results

383 patients were identified, 128 and 255 were treated with S+SRS and SRS, respectively. Median ages in the S+SRS and SRS groups were 62.2 (23.6–98.5) and 60.2 (20.2–97.4) (P 0.33). OS at 12 and 24 months was 69% and 41% vs 55% and 20% for the S+SRS and SRS groups, respectively hazard ratio (HR) 1.64 (1.23–2.18) (P<0.001). LF requiring salvage surgery at 12 and 24 months were 3% and 5% vs 8% and 10% for S+SRS and SRS groups, respectively (P 0.067). RN at 12 and 24 months were 9% and 17% vs 15% and 21% for S+SRS and SRS groups, respectively 1.32 HR (0.77–2.29) (P =0.32). PMD disease at 12 and 24 months were 16% and 21% vs 3% and 7% for S+SRS and SRS groups, respectively HR 0.26(0.12–0.56) (P < 0.001). LMD at 12 and 24 months were 4% and 6% vs 2% and 4% for S+SRS and SRS groups, respectively HR 0.73(0.25–2.17) (P 0.57).

Conclusion

Surgical resection plus SRS correlated with improved OS and a trend towards a decreased incidence of LF compared to SRS alone. However, patients treated with S experienced an increased incidence of PMD.

SURG-13. Multiplicity does not affect outcomes in patients with surgically treated brain metastases

Background

Having multiple brain lesions has been considered a negative prognostic factor in patients with brain metastases. The role of surgery in the management of these patients remains a matter of debate.

Methods

We retrospectively reviewed our patients who underwent surgical resection of brain metastases from January 2018 to December 2019, and examined outcomes including overall survival (OS), progression free survival (PFS) and rates of local failure.

Results

We identified 130 patients who underwent surgical resection as the primary treatment modality of brain metastases. At the time of surgery, 117 patients harbored 1–3 lesions, 13 had more than 3 lesions. Overall survival at two years for our entire cohort was 46%. The difference in OS between patients with > 3 metastases (21%) and 1–3 metastases (49%) was not statistically significant (HR=1.34, 95% CI: 0.67–2.68, p=0.41). Similarly, 27% of patients had PFS at two years, with 25% in the multiple metastases group and 28% in the comparison group (HR=1.19, 95% CI: 0.63–2.23, p=0.59). Additionally, 32% of patients overall experienced local failure at two years and there was no significant difference between patients with >3 metastases (15%) and those with fewer (33%) (HR=0.68, 95% CI: 0.21–2.19, p=0.52). A multivariate regression model examining multiple preoperative features revealed large tumor volume to be the only independent predictor of limited OS (p = 0.017) and PFS (p = 0.023), and local failure (p = 0.031).

Conclusions

In carefully selected patients, surgical resection is a reasonable management option for patients with multiple brain metastases.

Endoscopic extra-capsular resection of a giant pituitary adenoma: how I do it

BACKGROUND

Giant pituitary adenomas are characterized by their large size and potential to invade parasellar and suprasellar regions leading to visual decline and hypopituitarism. Thus, they remain a significant surgical challenge, and gross total removal is only achieved in the minority of cases.

METHOD

We aim to describe the key surgical steps for endoscopic extra-capsular resection of a giant pituitary adenoma with the aim of achieving complete tumor resection with description of the relevant surgical anatomy, indications and limitations.

CONCLUSION

Endoscopic extra-capsular resection of giant pituitary tumors when feasible allows for complete tumor resection, early identification of the gland and avoidance of manipulation of the optic apparatus.

The Importance of Long Term Follow Up After Endoscopic Pituitary Surgery: Durability of Results and Tumor Recurrence

Introduction

Endoscopic endonasal approach (EEA) has become the preferred surgical approach for resection of pituitary adenomas in most centers. This technique has a number of advantages such as improved visualization and maneuverability, when compared to microscopic transsphenoidal approach. However, the long-term results of this approach are still scarce. Ten years ago, we published our initial series of patients having undergone an endoscopic removal of their pituitary adenomas reporting favorable short-term results. This project aims to revisit the results of that series, addressing the long-term results regarding recurrence of pituitary adenomas.

Methods

A retrospective analysis of consecutive, endoscopically managed pituitary adenomas in a single center from 2004-2007. Only patients with >5 years of follow up (FU) and complete follow up data were included in this study. Recurrences were defined as evidence of any new tumor growth or enlargement of previously noted residual adenoma and/or biochemical recurrence of disease activity, in cases of functioning adenomas.

Results

A total of 98 patients matched the inclusion criteria for this study. The median follow-up period was 144 months. Nonfunctioning adenoma was the most common subtype (n = 66, 67.3%), followed by GH-secreting tumors (n = 19, 19.4%), ACTH-secreting tumors (n = 7, 7.1%), prolactinomas (n = 4, 4.1%) and TSH-secreting adenomas (n = 2, 2%). Age ranges from 23 to 82 years, with median age of 53 years. Preoperative visual deficits were observed in 46 patients (46.9%) and hormonal deficits were identified in 31% of cases. 22.4% of patients had undergone a previous pituitary adenomas resection prior to treatment in our center. Surgery achieved gross total resection (GTR) and near total resection (NTR) in 89 cases (90.8%) (56.1% and 34.7%, respectively). A total of 37 cases had recurrences during FU (mean recurrence free survival: 80 months). Recurrences were observed in 34% of patients who had had GTR while recurrences were observed in 39.5% of cases that underwent subtotal resection. Most recurrences occurred after 5 years of FU and univariate analysis demonstrated previous surgery (P = 0.005), cavernous sinus invasion (P = 0.05) and Ki-67 >5% (P = 0.01) to be factors associated with higher chance of recurrence. Multivariate Cox-regression analysis demonstrate that previous surgery and Ki-67 >5% are factors associated with recurrences. Surgery and/or radiation were utilized for management of recurrences in 29/37 cases.

Conclusion

Long-term FU analysis demonstrates that progression/recurrence of previously resected adenomas is observed in a significant number of patients, especially in those with previous/multiple surgical resections, elevated ki-67 and cavernous sinus invasion. Short-term FU may shadow real tumor control rates achieved after EEA and underscores the importance of long-term FU in these patients. Therefore, long-term FU should be pursued in all cases.

Current Results of Surgical Treatment of Craniopharyngiomas: The Impact of Endoscopic Endonasal Approaches

Surgery is the main treatment option for the management of craniopharyngiomas. Transcranial microsurgical approaches, such as pterional and subfrontal approaches, have constituted the classic operative strategy for resection of these tumors. However, the development of endoscopic endonasal approaches has revolutionized the treatment of craniopharyngiomas in the last 15 years, and endoscopic resection is favored for most craniopharyngiomas. In this article, we discuss our experience with the management of craniopharyngiomas and review the current results of the surgical treatment of those tumors, including discussion of goals of surgery, complications, recurrences, and the role of adjuvant treatment.

Adult isocitrate dehydrogenase-mutant brainstem glioma: illustrative case

BACKGROUND

Adult brainstem gliomas are rare entities that demonstrate heterogeneous biology and appear to be distinct from both their pediatric counterparts and adult supratentorial gliomas. Although the role of histone 3 mutations is being increasingly understood in this disease, the effect of isocitrate dehydrogenase (IDH) mutations remains unclear, largely because of limited data.

OBSERVATIONS

The authors present the case of a 29-year-old male with an IDH1-mutant, World Health Organization grade III anaplastic astrocytoma in the dorsal medulla, and they provide a review of the available literature on adult IDH-mutant brainstem glioma. The authors have amassed a cohort of 15 such patients, 7 of whom have survival data available. Median survival is 56 months in this small cohort, which is similar to that for IDH wild-type adult brainstem gliomas.

LESSONS

The authors' work reenforces previous literature suggesting that the role of IDH mutation in glioma differs between brainstem and supratentorial lesions. Therefore, the authors advocate that adult brainstem gliomas be studied in terms of major molecular subgroups (including IDH mutant) because these gliomas may exhibit fundamental differences from each other, from pediatric brainstem gliomas, and from adult supratentorial gliomas.

Expanded Endoscopic Endonasal Approach for Removal of a Tuberculum Sella Meningioma

This 46-year-old female patient presented after a 6-month progressive right-sided visual loss, with a visual acuity of 20/60, a temporo/infranasal visual field deficit, and optic atrophy. The magnetic resonance imaging disclosed a tuberculum sella meningioma with minimal right medial canal invasion, however, no encasement of carotid arteries. Tuberculum sella meningiomas represent 5%-10% of intracranial meningiomas and are surgically challenging tumors that can severely hinder vision. The endoscopic approach allows for early coagulation of the tumor meningeal supply, and importantly, facilitates gross total removal without any manipulation of the optic nerve while preserving the superior hypophyseal arteries.^1-9.

A systematic review of surgical treatments of idiopathic intracranial hypertension (IIH)

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

Dissecting the default mode network: direct structural evidence on the morphology and axonal connectivity of the fifth component of the cingulum bundle

OBJECTIVE

Although a growing body of data support the functional connectivity between the precuneus and the medial temporal lobe during states of resting consciousness as well as during a diverse array of higher-order functions, direct structural evidence on this subcortical circuitry is scarce. Here, the authors investigate the very existence, anatomical consistency, morphology, and spatial relationships of the cingulum bundle V (CB-V), a fiber tract that has been reported to reside close to the inferior arm of the cingulum (CingI).

METHODS

Fifteen normal, formalin-fixed cerebral hemispheres from adults were treated with Klingler's method and subsequently investigated through the fiber microdissection technique in a medial to lateral direction.

RESULTS

A distinct group of fibers is invariably identified in the subcortical territory of the posteromedial cortex, connecting the precuneus and the medial temporal lobe. This tract follows the trajectory of the parietooccipital sulcus in a close spatial relationship with the CingI and the sledge runner fasciculus. It extends inferiorly to the parahippocampal place area and retrosplenial complex area, followed by a lateral curve to terminate toward the fusiform face area (Brodmann area [BA] 37) and lateral piriform area (BA35). Taking into account the aforementioned subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial, facial, and mnemonic information to the precuneal hub. Although robust clinical evidence on the functional role of this stream is lacking, the modern neurosurgeon should be aware of this tract when manipulating cerebral areas en route to lesions residing in or around the ventricular trigone.

CONCLUSIONS

Through the fiber microdissection technique, the authors were able to provide original, direct structural evidence on the existence, morphology, axonal connectivity, and correlative anatomy of what proved to be a discrete white matter pathway, previously described as the CB-V, connecting the precuneus and medial temporal lobe.

Mapping the human middle longitudinal fasciculus through a focused anatomo-imaging study: shifting the paradigm of its segmentation and connectivity pattern

Τhe middle longitudinal fasciculus (MdLF) was initially identified in humans as a discrete subcortical pathway connecting the superior temporal gyrus (STG) to the angular gyrus (AG). Further anatomo-imaging studies, however, proposed more sophisticated but conflicting connectivity patterns and have created a vague perception on its functional anatomy. Our aim was, therefore, to investigate the ambiguous structural architecture of this tract through focused cadaveric dissections augmented by a tailored DTI protocol in healthy participants from the Human Connectome dataset. Three segments and connectivity patterns were consistently recorded: the MdLF-I, connecting the dorsolateral Temporal Pole (TP) and STG to the Superior Parietal Lobule/Precuneus, through the Heschl's gyrus; the MdLF-II, connecting the dorsolateral TP and the STG with the Parieto-occipital area through the posterior transverse gyri and the MdLF-III connecting the most anterior part of the TP to the posterior border of the occipital lobe through the AG. The lack of an established termination pattern to the AG and the fact that no significant leftward asymmetry is disclosed tend to shift the paradigm away from language function. Conversely, the theory of "where" and "what" auditory pathways, the essential relationship of the MdLF with the auditory cortex and the functional role of the cortical areas implicated in its connectivity tend to shift the paradigm towards auditory function. Allegedly, the MdLF-I and MdLF-II segments could underpin the perception of auditory representations; whereas, the MdLF-III could potentially subserve the integration of auditory and visual information.

Management of Giant Pituitary Adenomas: Role and Outcome of the Endoscopic Endonasal Surgical Approach

Giant adenomas represent a significant surgical challenge. Although traditionally several transcranial and transsphenoidal microscopic approaches have had a central role in their management, in the last 2 decades here have been increasing reports of the endoscopic endonasal approach for giant adenomas, citing its improved resection rates and lower complication profile. However, its role as the preferred approach has not been fully established and there is currently a paucity of evidence-based recommendations available in the literature. This article reviews the current literature and attempts to define the role and outcomes of the endoscopic endonasal surgical approach for giant pituitary adenomas.

Angiosarcoma-related cerebral metastases: a systematic review of the literature

Angiosarcoma-related cerebral metastases have only been recorded in a few case reports and case series and have not been systematically reviewed to date. Our objective was therefore to perform a systematic literature review on cases of angiosarcomas metastasizing to the brain to inform current practice. All three major libraries-PubMed/MEDLINE, Embase, and Cochrane-were systematically searched, until January 2019. Articles in English reporting angiosarcoma-related cerebral metastases via hematogenous route were included. Our search yielded 45 articles (38 case reports, 5 retrospective studies, 1 case series and 1 letter to the editor), totaling 48 patients (mean age 47.9 years). The main primary site was the heart. The mean time of diagnosis of cerebral metastases following primary tumor identification was 4.9 months. In 15 cases, the brain was the only metastatic site. In cases of multiple extracerebral metastases, the most common sites were the lung and bone. Acute intracerebral supratentorial hemorrhage was the most common presenting radiological feature. Treatment strategies were almost equally divided between the surgical (with or without adjuvant treatment) and the medical arm. Mean overall survival was 7.2 months while progression-free survival was 1.5 months. To our knowledge, this is the first systematic literature review on angiosarcoma-related cerebral metastases. This pathology proves to be an extremely rare clinical entity and carries a poor prognosis, and no consensus has been reached regarding treatment.

The Parieto-Occipital Artery Revisited: A Microsurgical Anatomic Study

BACKGROUND

The parieto-occipital artery (PoA) is the terminal posterior cerebral artery branch, which typically runs in the parieto-occipital sulcus. Previous studies have highlighted variation in the PoA origin and branching pattern and their clinical implications. Nevertheless, PoA anastomoses have not been systematically investigated. The present study aimed to assess whether putative variation in PoA origin and its branching as well as anastomotic pattern is associated with differences in demographic/anthropometric variables.

METHODS

In 15 cadaveric heads, PoA anatomic features were quantified and assessed in relation to demographic/anthropometric variables.

RESULTS

The mean distance of PoA origin from the posterior limit of the splenium and the occipital pole (OP) is 3.1 and 53.1 mm, respectively. The latter is significantly longer in taller individuals. The PoA supplies a mean of 10.5 and 9.1 branches to the precuneus and cuneus, respectively. PoA anastomoses primarily involve the precuneal artery complex (PAc) and the calcarine artery. The analysis indicated significant, positive correlations between the distance of PoA origin from the OP and the number of PoA anastomoses and between the number of PoA precuneal and cuneal branches.

CONCLUSIONS

Although the PoA invariably supplies the precuneus and almost always the cuneus, its direct contribution to the former seems inferior to PAc. Nevertheless, the PoA frequently shows putative collateral supply networks to the precuneus and cuneus via anastomoses with the PAc and calcarine artery, respectively. The distance between PoA origin and OP varies with an individual's height; the frequency of intrahemispheric PoA anastomoses varies with its site of origin.

The carotico-clinoid bar: A systematic review and meta-analysis of its prevalence and potential implications in cerebrovascular and skull base surgery

BACKGROUND

The caroticoclinoid bar (CCB) is implicated in both transcranial and endonasal surgery. Its morphology reflects differences in the microsurgical anatomy of the parasellar area while its manipulation during an anterior or middle clinoidectomy can result in ICA injury. Although safe surgical access to the paraclinoidal region is related to adjustment of surgical technique according to CCB anatomical variants, a review of the literature indicates the lack of a systematic assortment of published data regarding the prevalence of this variable structure. As such the topic needs further investigation.

OBJECTIVE

To systematically review and document the prevalence of the CCB and its anatomic variations.

METHODS

3 Databases were systematically reviewed according to the PRISMA statement through August of 2018 for the identification of relevant studies.

RESULTS

A total of 27 articles (7,521 subjects/specimens, 14,449 sides) were included in this meta-analysis. The overall pooled prevalence of the CCB was 32.6% (95% CI 26.6% - 38.8%) when measured over subjects/specimens and 23.6% (95% CI 19.7% - 27.6%) when measured over sides. Overall prevalence of the CCB reported from imaging studies was 23.1% (95% CI 8.9% - 41.4%) when measured over subjects/specimens and 18.7% (95% CI 12.6% - 25.7%) when measured over sides. Moreover, the CCB was slightly more prevalent (p = 0.050), on the right side.

CONCLUSION

Our results indicate considerable CCB prevalence rates and that imaging studies report lower prevalence rates. Although meticulous preoperative investigation is mandatory, surgeons carrying for patients with parasellar pathologies should always be vigilant about this structure.

Survival effects of a strategy favoring second-line multimodal treatment compared to supportive care in glioblastoma patients at first progression

OBJECTIVEData on the survival effects of supportive care compared to second-line multimodal treatment for glioblastoma progression are scarce. Thus, the authors assessed survival in two population-based, similar cohorts from two European university hospitals with different treatment strategies at first progression.METHODSThe authors retrospectively identified patients with newly diagnosed glioblastoma treated at two neurooncological centers. After diagnosis, patients from both centers received identical treatments, but at tumor progression each center used a different approach. In the majority of cases, at center A (Greece), supportive care or a single therapeutic modality was offered at progression, whereas center B (Germany) provided multimodal second-line therapy. The main outcome measure was survival after progression (SaP). The influence of the treatment strategy on SaP was assessed by multivariate analysis.RESULTSOne hundred three patients from center A and 156 from center B were included. Tumor progression was observed in 86 patients (center A) and 136 patients (center B). At center A, 53 patients (72.6%) received supportive care alone, while at center B, 91 patients (80.5%) received second-line treatment. Progression-free survival at both centers was similar (9.4 months [center A] vs 9.0 months [center B]; p = 0.97), but SaP was significantly improved in the patients treated with multimodal second-line therapy at center B (7 months, 95% CI 5.3-8.7 months) compared to those treated with supportive care or a single therapeutic modality at center A (4.5 months, 95% CI 3.5-5.5 months; p = 0.003). In the multivariate analysis, the treatment center was an independent prognostic factor for overall survival (HR 1.59, 95% CI 0.17-2.15; p = 0.002).CONCLUSIONSTreatment strategy favoring multimodal second-line treatment over minimal treatment or supportive care at glioblastoma progression is associated with significantly better overall survival.

Finger tapping and verbal fluency post-tap test improvement in INPH: its value in differential diagnosis and shunt-treatment outcomes prognosis

BACKGROUND

Idiopathic normal pressure hydrocephalus (INPH) diagnosis is challenging as it can be mimicked by other neurological conditions, such as neurodegenerative dementia and motor syndromes. Additionally, outcomes after lumbar puncture (LP) tap test and shunt treatment may vary due to the lack of a common protocol in INPH assessment. The present study aimed to assess whether a post-LP test amelioration of frontal cognitive dysfunctions, characterizing this syndrome, can differentiate INPH from similar neurological conditions and whether this improvement can predict INPH post-shunt outcomes.

METHOD

Seventy-one consecutive patients referred for INPH suspicion and LP testing, were enrolled. According to the consensus guidelines criteria, 29 patients were diagnosed as INPH and 42 were assigned an alternative diagnosis (INPH-like group) after reviewing clinical, neuropsychological and imaging data, and before LP results. A comprehensive neuropsychological assessment for frontal executive, upper extremity fine motor functions, aphasias, apraxias, agnosias and gait evaluation were administered at baseline. Executive, fine motor functions and gait were re-examined post-LP test in all patients and post-shunt placement in INPH patients.

RESULTS

Of the INPH patients, 86.2% showed cognitive amelioration in the post-LP test; in addition, all but one (97%) presented with neurocognitive and gait improvement post-shunt. Verbal phonological fluency and finger tapping task post-LP improvement predicted positive clinical outcome post-shunt. None of the INPH-like group presented with neurocognitive improvement post-LP.

CONCLUSIONS

Post-LP amelioration of verbal fluency and finger tapping deficits can differentiate INPH from similar disorders and predict positive post-shunt clinical outcome in INPH. This becomes of great importance when gait assessment is difficult to perform in clinical practice.