Citations

OBJECTIVE Although it is still early in its application, laser interstitial thermal therapy (LiTT) has increasingly been employed as a surgical option for patients with mesial temporal lobe epilepsy. This study aimed to describe mesial temporal lobe ablation volumes and seizure outcomes following LiTT across the Mayo Clinic’s 3 epilepsy surgery centers. METHODS This was a multi-site, single-institution, retrospective review of seizure outcomes and ablation volumes following LiTT for medically intractable mesial temporal lobe epilepsy between October 2011 and October 2015. Pre-ablation and post-ablation follow-up volumes of the hippocampus were measured using FreeSurfer, and the volume of ablated tissue was also measured on intraoperative MRI using a supervised spline-based edge detection algorithm. To determine seizure outcomes, results were compared between those patients who were seizure free and those who continued to experience seizures. RESULTS There were 23 patients who underwent mesial temporal LiTT within the study period. Fifteen patients (65%) had left-sided procedures. The median follow-up was 34 months (range 12–70 months). The mean ablation volume was 6888 mm 3 . Median hippocampal ablation was 65%, with a median amygdala ablation of 43%. At last follow-up, 11 (48%) of these patients were seizure free. There was no correlation between ablation volume and seizure freedom (p = 0.69). There was also no correlation between percent ablation of the amygdala (p = 0.28) or hippocampus (p = 0.82) and seizure outcomes. Twelve patients underwent formal testing with computational visual fields. Visual field changes were seen in 67% of patients who underwent testing. Comparing the 5 patients with clinically noticeable visual field deficits to the rest of the cohort showed no significant difference in ablation volume between those patients with visual field deficits and those without (p = 0.94). There were 11 patients with follow-up neuropsychological testing. Within this group, verbal learning retention was 76% in the patients with left-sided procedures and 89% in those with right-sided procedures. CONCLUSIONS In this study, there was no significant correlation between the ablation volume after LiTT and seizure outcomes. Visual field deficits were common in formally tested patients, much as in patients treated with open temporal lobectomy. Further studies are required to determine the role of amygdalohippocampal ablation.

Abstract Objective . An ability to map seizure-generating brain tissue, i.e. the seizure onset zone (SOZ), without recording actual seizures could reduce the duration of invasive EEG monitoring for patients with drug-resistant epilepsy. A widely-adopted practice in the literature is to compare the incidence (events/time) of putative pathological electrophysiological biomarkers associated with epileptic brain tissue with the SOZ determined from spontaneous seizures recorded with intracranial EEG, primarily using a single biomarker. Clinical translation of the previous efforts suffers from their inability to generalize across multiple patients because of (a) the inter-patient variability and (b) the temporal variability in the epileptogenic activity. Approach . Here, we report an artificial intelligence-based approach for combining multiple interictal electrophysiological biomarkers and their temporal characteristics as a way of accounting for the above barriers and show that it can reliably identify seizure onset zones in a study cohort of 82 patients who underwent evaluation for drug-resistant epilepsy. Main results . Our investigation provides evidence that utilizing the complementary information provided by multiple electrophysiological biomarkers and their temporal characteristics can significantly improve the localization potential compared to previously published single-biomarker incidence-based approaches, resulting in an average area under ROC curve (AUC) value of 0.73 in a cohort of 82 patients. Our results also suggest that recording durations between 90 min and 2 h are sufficient to localize SOZs with accuracies that may prove clinically relevant. Significance . The successful validation of our approach on a large cohort of 82 patients warrants future investigation on the feasibility of utilizing intra-operative EEG monitoring and artificial intelligence to localize epileptogenic brain tissue. Broadly, our study demonstrates the use of artificial intelligence coupled with careful feature engineering in augmenting clinical decision making.

AbstractBackgroundThe purpose of this study was to determine the clinical outcomes and review the management strategies for metastatic esthesioneuroblastoma.MethodsWe conducted a systematic review and meta‐analysis.ResultsForty‐eight studies totaling 118 patients met inclusion criteria. Chemotherapy in combination with surgery and/or radiation exhibited the best overall survival when compared to monotherapy and no treatment (P < .001). However, most patients (66%) received either monotherapy or no therapy. The number and location of metastases among the 3 treatment groups did not significantly differ (P = .85). Treatment modality remained significantly associated with overall survival on multivariable analysis (P < .001). Platinum‐based chemotherapy was most commonly utilized but did not provide a survival benefit when compared with all other regimens (P = .88).ConclusionDistant metastases with esthesioneuroblastoma portend a poor prognosis. Chemotherapy in combination with surgery and/or radiation was associated with improved overall survival. Further research into the optimal systemic therapeutic regimen for patients with distant metastases is critical.

ObjectivesPrimary skull base lymphoma (PSBL) represents a rare manifestation of extranodal lymphoma. Presenting with nonspecific symptomatology and imaging findings, PSBL often masquerades as more common cranial base pathology and thus can present a diagnostic challenge. The objectives of this study were to characterize the manifestations and clinical outcomes of PSBL.Study DesignCase series and chart review.SettingTertiary referral center.Subjects and MethodsReview of 48 patients with PSBL treated between 1994 and 2016.ResultsThe median age at diagnosis was 60 years. Diffuse large B‐cell lymphoma comprised the most common subtype (56%). Presenting symptoms included diplopia (52%), trigeminal hypesthesia (38%), headache (29%), facial nerve weakness (25%), B‐symptoms (fevers, night sweats, and/or weight loss) (25%), and hearing loss (21%). Discrete lesions commonly mimicked meningioma, schwannoma, and nasopharyngeal carcinoma. Diffuse lesions imitated neurosarcoidosis, granulomatosis with polyangiitis, and carcinomatosis meningitis. Only 26% of all initial clinical evaluations suspected lymphoma. The combination of restricted diffusion on diffusion‐weighted imaging, an absence of flow voids or surrounding hyperostosis, bony erosion and/or marrow signal replacement, and heterogeneous contrast enhancement facilitated delineation between PSBL and common skull base pathology. Cerebrospinal fluid (CSF) analysis was diagnostic of lymphoma in 24% of cases. Lymphoma within CSF portended significantly worse overall survival (85% vs 18% at 3‐years; P <. 001).ConclusionA history significant for multiple cranial nerve palsies, B‐symptoms, and imaging findings inconsistent with common skull base pathology should raise suspicion for PSBL. CSF analysis in the setting of PSBL can provide diagnostic and prognostic value for patients.

Objective(1) Assess 3‐dimensional volumetric growth of untreated sporadic vestibular schwannomas (VSs) in a large cohort of patients treated with conservative observation. (2) Compare volumetric and conventional linear diameter measurements for detecting tumor growth.Study DesignCase series with chart review.SettingTertiary skull base referral center.Subjects and MethodsPatients with sporadic VS who elected initial conservative treatment with at least 2 serial magnetic resonance imaging (MRI) scans were included. Tumor volume was determined with 3‐dimensional segmentation of MRI sequences. The volumetric threshold for tumor growth was an increase ≥20% from baseline tumor volume. Tumor size based on linear diameter was assessed with the 1995 American Academy of Otolaryngology—Head and Neck Surgery Foundation guidelines for VS outcome reporting, with growth defined as an increase ≥2 mm.ResultsA total of 361 patients were included with a median radiologic follow‐up of 4.1 years (interquartile range [IQR], 2.5‐6.8). At diagnosis, 232 VSs (64%) were purely intracanalicular, and 129 (36%) extended into the cerebellopontine angle. The median baseline tumor volume was 0.161 cm3 (IQR, 0.054‐0.418). Overall, 69% of tumors demonstrated volumetric growth at a median of 1.1 years (IQR, 0.6‐2.1) after initial MRI. In contrast, based on linear measurement assessment, 48% of tumors demonstrated growth at a median of 1.8 years (IQR, 0.8‐3.1) from first MRI scan. Disequilibrium, facial hypoesthesia, aural fullness, initial tumor size, and nonincidental diagnosis were associated with tumor growth.ConclusionThree‐dimensional volumetric assessment of VS provides a more sensitive measure of tumor growth when compared with linear diameter assessment. Through volumetric analysis, the current study revealed that a significant proportion of VSs demonstrate growth during observation.

Objectives Neck metastases in patients with esthesioneuroblastoma (ENB) constitute the most significant predictor of poor long-term survival. Recently, researchers discovered the existence of dural lymphatic channels that drain to the cervical lymph nodes. From this physiologic basis, we hypothesized that patients with ENB who develop dural invasion (DI) would exhibit a proclivity for neck metastases. Design Retrospective review. Setting Tertiary referral center. Participants All patients treated for ENB from January 1, 1994 to December 31, 2015. Main Outcome Measures Incidence, laterality, and recurrence rate of neck metastases by DI status. Results Sixty-one patients were identified (38% female; median age 49, range, 10–80), 34 (56%) of whom had DI and 27 (44%) did not. Of patients with DI, 50% presented with or developed neck disease following treatment compared with just 22% of those without DI (p = 0.026). Bilateral neck disease was more common in patients with DI (11/34, 32%) compared with those without (2/27, 7%) (p = 0.018). Five-year regional recurrence-free survival rates were 88% for those without and 64% for those with DI (p = 0.022). Kadish C patients with DI were more likely to develop regional recurrence when compared with Kadish C without DI and Kadish A/B (p = 0.083). Further, Kadish C patients with DI displayed worse overall survival than Kadish C without DI and Kadish A/B. Kadish D patients displayed the worst overall survival. The difference in overall survival among these four groups was significant (p < 0.001). Conclusion DI by ENB is associated with increased incidence of cervical nodal metastases, bilateral neck disease, worse regional recurrence-free survival, and poorer overall survival. These data support the division of Kadish C by DI status.