Etiology and Management of Recurrent and Persistent Hemifacial Spasm-A Single-Center Experience.

BACKGROUND AND OBJECTIVES: Despite a 90% success rate, microvascular decompression occasionally fails to resolve hemifacial spasm (HFS), necessitating revision surgery. We investigated recurrent cases to identify underlying causes. METHODS: We evaluated patients at our institution who underwent revision microvascular decompression because of recurrent or persistent HFS, assessing recurrence causes, decompression techniques, complications, and outcomes. Data considered included demographics, preoperative symptoms, disease duration, offending vessel, and magnetic resonance findings. Surgical notes and intraoperative videos were reviewed, and telephone interviews were conducted for recent outcomes. RESULTS: Out of our ongoing series of 493 patients, 43 patients (8.7%) required revision surgery with a patient cohort of 33 females and 10 males. The average symptom duration was 10 years. The median time between primary and revision surgery was 14 months. Thirteen patients (30.2%) underwent initial surgery elsewhere. Adhesions of Teflon pledgets to the facial nerve were the primary cause of nonresolution in 23 patients (53.5%), while in 13 (30.2%), a missed vascular compression was identified. Sixteen patients (37.2%) had sufficient decompression by removing the conflicting pledgets. During 10 revisions (23.3%), additional Teflon pledgets were necessary. After a median follow-up of 67 months after revision surgery, 27 patients (62.8%) reported complete spasm resolution. Six patients (14.0%) had a good outcome with over 90% reduction of their spasms, 3 patients (7.0%) stated a fair outcome (50% improvement), while 7 patients (16.3%) had no improvement. CONCLUSION: According to our results, adhesions of Teflon to the facial nerve may cause HFS recurrence. Therefore, whenever possible, Teflon should be placed without nerve contact between the brainstem and the offending vessel. Using a sling or bridge technique seems to be beneficial because it leaves the facial nerve completely free. Persistent symptoms often result from missed offending vessels in the pontomedullary sulcus indicating the benefit of endoscopic inspection of this area with an endoscope.

MET receptor serves as a promising target in melanoma brain metastases.

The development of brain metastases hallmarks disease progression in 20-40% of melanoma patients and is a serious obstacle to therapy. Understanding the processes involved in the development and maintenance of melanoma brain metastases (MBM) is critical for the discovery of novel therapeutic strategies. Here, we generated transcriptome and methylome profiles of MBM showing high or low abundance of infiltrated Iba1high tumor-associated microglia and macrophages (TAMs). Our survey identified potential prognostic markers of favorable disease course and response to immune checkpoint inhibitor (ICi) therapy, among them APBB1IP and the interferon-responsive gene ITGB7. In MBM with high ITGB7/APBB1IP levels, the accumulation of TAMs correlated significantly with the immune score. Signature-based deconvolution of MBM via single sample GSEA revealed enrichment of interferon-response and immune signatures and revealed inflammation, stress and MET receptor signaling. MET receptor phosphorylation/activation maybe elicited by inflammatory processes in brain metastatic melanoma cells via stroma cell-released HGF. We found phospho-METY1234/1235 in a subset of MBM and observed a marked response of brain metastasis-derived cell lines (BMCs) that lacked druggable BRAF mutations or developed resistance to BRAF inhibitors (BRAFi) in vivo to MET inhibitors PHA-665752 and ARQ197 (tivantinib). In summary, the activation of MET receptor in brain colonizing melanoma cells by stromal cell-released HGF may promote tumor self-maintenance and expansion and might counteract ICi therapy. Therefore, therapeutic targeting of MET possibly serves as a promising strategy to control intracranial progressive disease and improve patient survival.

Rare clival localization of an eosinophilic granuloma: illustrative case.

BACKGROUND: Eosinophilic granuloma (EG) belongs to the family of Langerhans cell histiocytosis (LCH) and is considered to be a benign disease typically found in children younger than 15 years of age. Here, the authors describe an EG of unusual localization and clinical presentation. OBSERVATIONS: The authors report a 9-year-old girl with an EG presenting as an osteolytic lesion of the clivus. After transsphenoidal resection and histological confirmation, adjuvant chemotherapy was initiated. Presenting signs and symptoms were weight loss, episodic grimacing, and moderate ballism-like movements. After a follow-up-period of 32 months, the patient presented with a total resolution of initial symptoms and no further tumor growth. LESSONS: Although these lesions are rare, one should consider EG as a differential diagnosis when confronted with osteolytic lesions of the clivus.

Duration of Surgery and Intraoperative Blood Pressure Management Are Modifiable Risk Factors for Postoperative Neurocognitive Disorders After Spine Surgery: Results of the Prospective CONFESS Study.

STUDY DESIGN: Prospective quasi-experimental observational study. OBJECTIVE: The objective of this study was to evaluate whether duration of surgery is a modifiable risk factor for postoperative delirium (POD) after spine surgery and explore further modifiable risk factors. In addition, we sought to investigate the association between POD and postoperative cognitive dysfunction and persistent neurocognitive disorders. SUMMARY OF BACKGROUND DATA: Advances in spine surgery enable technically safe interventions in elderly patients with disabling spine disease. The occurrence of POD and delayed neurocognitive complications ( e.g. postoperative cognitive dysfunction/persistent neurocognitive disorder) remain a concern since these contribute to inferior functional outcomes and long-term care dependency after spine surgery. MATERIALS AND METHODS: This prospective single-center study recruited patients aged 60 years or above and scheduled for elective spine surgery between February 2018 and March 2020. Functional (Barthel Index, BI) and cognitive outcomes [Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test battery; telephone Montréal Cognitive Assessment] were assessed at baseline, three (V3), and 12 months postoperatively. The primary hypothesis was that the duration of surgery predicts POD. Multivariable predictive models of POD included surgical and anesthesiological parameters. RESULTS: Twenty-two percent of patients developed POD (n=22/99). In a multivariable model, duration of surgery [OR adj =1.61/h (95% CI, 1.20-2.30)], age [OR adj =1.22/yr (95% CI, 1.10-1.36)], and baseline deviations of intraoperative systolic blood pressure [25th percentile: OR adj =0.94/mm Hg (95% CI, 0.89-0.99); 90th percentile: OR adj =1.07/mm Hg (95% CI, 1.01-1.14)] were significantly associated with POD. Postoperative cognitive scores generally improved (V3, ΔCERAD total z -score: 0.22±0.63). However, this positive group effect was counteracted by POD [beta: -0.87 (95% CI, -1.31 to 0.42)], older age [beta: -0.03/yr (95% CI, -0.05 to 0.01)], and lack of functional improvement [ΔBI; beta: -0.04/point (95% CI, -0.06 to 0.02)]. Cognitive scores at twelve months remained inferior in the POD group, adjusted for baseline cognition/age. CONCLUSIONS: This study identified distinct neurocognitive effects after spine surgery, which are influenced by perioperative risk factors. Potential cognitive benefits are counteracted by POD, rendering its prevention critical in an aging population.

Pharmacologic Inhibition of ADAM10 Attenuates Brain Tissue Loss, Axonal Injury and Pro-inflammatory Gene Expression Following Traumatic Brain Injury in Mice.

The α-secretase A disintegrin and metalloprotease 10 (ADAM10) regulates various physiological and pathophysiological processes. Despite its broad functional implications during development, plasticity, and disease, no pharmacological approaches to inhibit ADAM10 in acute brain injury have been reported. Here, we examined the effects of the ADAM10 inhibitor GI254023X on the neurological and histopathological outcome after experimental traumatic brain injury (TBI). C57BL/6N mice were subjected to the controlled cortical impact (CCI) model of TBI or sham procedure and received GI254023X or vehicle during the acute phase of injury (n = 40, 100 mg/kg, 25% DMSO, 0.1 M Na2CO3, intraperitoneal, 30 min and 24 h after TBI). GI254023X treatment did not improve neurological deficits from 1 to 7 days post-injury (dpi) but animals treated with GI254023X exhibited smaller brain lesions compared to vehicle treatment. Determination of brain mRNA expression by quantitative PCR showed that TBI-induced up-regulation of Adam10 and Adam17 was not influenced by GI254023X but the up-regulation of the matrix metalloproteinase genes Mmp2 and Mmp9 was attenuated. GI254023X treatment further increased the T cell marker Cd247 but did not affect blood brain barrier integrity, as assessed by Occludin mRNA expression and IgG brain extravasation. However, in agreement with neuroprotective effects of ADAM10 inhibition, GI254023X treatment attenuated axonal injury, as indicated by decreased generation of spectrin breakdown products (SBDPs) and decreased immunostaining using anti-non-phosphorylated neurofilament (SMI-32). Interestingly, reduced axonal injury in GI254023X-treated animals coincided with subtle mRNA dysregulation in the glutamate receptor subunit genes Gria1 and Grin2b. Quantitative PCR also revealed that GI254023X mitigated up-regulation of the pro-inflammatory markers Il6, Tnfa, and Lcn2 but not the up-regulation of the pan-microglia marker Aif1, the M2 microglia marker Arg1 and the reactive astrocyte marker Gfap. Taken together, the ADAM10 inhibitor GI254023X attenuates brain tissue loss, axonal injury and pro-inflammatory gene expression in the CCI model of TBI. These results suggest that ADAM10 may represent a therapeutic target in the acute phase of TBI.

Tear-drop technique in iliac screw placement: a technical analysis.

BACKGROUND: Instrumentation of the lumbosacral region is one of the more challenging regions due to the complex anatomical structures and biomechanical forces. Screw insertion can be done both navigated and based on X-ray verification. In this study, we demonstrate a fast and reliable open, low exposure X-ray-guided technique of iliac screw placement. METHODS: Between October 2016 and August 2019, 48 patients underwent sacropelvic fixation in tear-drop technique. Screw insertion was performed in open technique by using an X-ray converter angulated 25-30° in coronal and sagittal view. The anatomical insertion point was the posterior superior iliac spine. Verification of correct screw placement was done by intraoperative 3D scan. RESULTS: In total, 95 iliac screws were placed in tear-drop technique with a correct placement in 98.1%. CONCLUSIONS: The tear-drop technique showed a proper screw position in the intraoperative 3D scan and therefore may be considered an alternative technique to the navigated screw placement.

GD2 targeting by dinutuximab beta is a promising immunotherapeutic approach against malignant glioma.

PURPOSE: Disialoganglioside GD2 is expressed by glioblastoma multiforme (GBM) cells representing a promising target for anti-GD2 immunotherapeutic approaches. The aim of the present study was to investigate anti-tumor efficacy of the chimeric anti-GD2 antibody (Ab) dinutuximab beta against GBM. METHODS: Expression levels of GD2 and complement regulatory proteins (CRP; CD46, CD55 and CD59) on well-known and newly established primary tumor originated GBM cell lines were analyzed by flow cytometry. Ab-dependent cellular (ADCC) and complement-dependent cytotoxicity (CDC) mediated by dinutuximab beta against GBM cells were determined by a non-radioactive calcein-AM-based assay. RESULTS: Analysis of primary GBM cells revealed a heterogeneous GD2 expression that varied between the cell lines analyzed with higher expression levels in the tumor surface compared to the core originated cells. Both GD2-positive and -negative tumor cells were detected in every cell line analyzed. In contrast to CDC, ADCC mediated by dinutuximab beta was observed against the majority of GBM cells. Importantly, CDC-resistant cells showed high expression of the CRP CD46, CD55 and CD59. CONCLUSION: Our present data show anti-tumor effects mediated by dinutuximab beta against GBM cells providing a rationale for a GD2-directed immunotherapy against GBM. Due to high CRP expression, a combining of GD2-targeting with CRP blockade might be a further treatment option for GBM.