Permanent Cerebrospinal Fluid Diversion in Adults With Posterior Fossa Tumors: Incidence and Predictors.

BACKGROUND: Posterior fossa tumors (PFTs) can cause hydrocephalus. Hydrocephalus can persist despite resection of PFTs in a subset of patients requiring permanent cerebrospinal fluid (CSF) diversion. Characteristics of this patient subset are not well defined. OBJECTIVE: To define preoperative and postoperative variables that predict the need for postoperative CSF diversion in adult patients with PFTs. METHODS: We surveyed the CNS (Central Nervous System) Tumor Outcomes Registry at Emory (CTORE) for patients who underwent PFT resection at 3 tertiary-care centers between 2006 and 2019. Demographic, radiographic, perioperative, and dispositional data were analyzed using univariate and multivariate models. RESULTS: We included 617 patients undergoing PFT resection for intra-axial (57%) or extra-axial (43%) lesions. Gross total resection was achieved in 62% of resections. Approximately 13% of patients required permanent CSF diversion/shunting. Only 31.5% of patients who required pre- or intraop external ventricular drain (EVD) placement needed permanent CSF diversion. On logistic regression, size, transependymal flow, use of perioperative EVD, postoperative intraventricular hemorrhage (IVH), and surgical complications were predictors of permanent CSF diversion. Preoperative tumor size was only independent predictor of postoperative shunting in patients with subtotal resection. In patients with intra-axial tumors, transependymal flow (P = .014), postoperative IVH (P = .001), surgical complications (P = .013), and extent of resection (P = .03) predicted need for shunting. In extra-axial tumors, surgical complications were the major predictor (P = .022). CONCLUSION: Our study demonstrates that presence of preoperative hydrocephalus in patients with PFT does not necessarily entail the need for permanent CSF diversion. We report the major predictive factors for needing permanent CSF diversion.

Magnetic resonance-guided laser interstitial thermal therapy for posterior fossa neoplasms.

PURPOSE: Magnetic resonance-guided laser interstitial thermal therapy (LITT) has been increasingly used to treat a number of intracranial pathologies, though its use in the posterior fossa has been limited to a few small series. We performed a multi-institutional review of targets in the posterior fossa, reporting the efficacy and safety profile associated with laser ablation in this region of the brain. METHODS: A retrospective review of patients undergoing LITT in the posterior fossa was performed from August 2010 to March 2020. Patient demographic information was collected alongside the operative parameters and patient outcomes. Reported outcomes included local control of the lesion, postoperative complications, hospital length of stay, and steroid requirements. RESULTS: 58 patients across four institutions underwent LITT in the posterior fossa for 60 tumors. The median pre-ablation tumor volume was 2.24 cm3. 48 patients (50 tumors) were available for follow-up. An 84% (42/50) overall local control rate was achieved at 9.5 months median follow up. There were two procedural complications, including insertional hemorrhage and laser misplacement and 12/58 (21%) patients developed new neurological deficits. There was one procedure related death. The median length of hospital stay was 1 day, with 20.7% of patients requiring discharge to a rehabilitation facility. CONCLUSIONS: LITT is an effective approach for treating pathology in the posterior fossa. The average target size is smaller than what has been reported in the supratentorial space. Care must be taken to prevent injury to surrounding structures given the close proximity of critical structures in this region.

Emerging and investigational targeted chemotherapy and immunotherapy agents for metastatic brain tumors.

INTRODUCTION: Metastases to the central nervous system are the most common cause of malignant intracranial tumors in adults. Current standard of care includes surgery and radiation, but overall survival remains poor. A range of systemic therapies are emerging as promising treatment options for these patients. AREAS COVERED: This study reviews novel drug regimens that are under investigation in phase 1 and 2 clinical trials. To identify relevant therapies under clinical investigation, a search was performed on http://clinicaltrials.gov and Pubmed with the keywords brain metastasis, Phase I clinical trial, and Phase II clinical trial from 2016 to 2020. The authors detail the mechanisms of action of all trial agents, outline evidence for their utility, and summarize the current state of the field. EXPERT OPINION: Current advancements in the medical management of brain metastases can be categorized into targeted therapies, methods of overcoming treatment resistance, novel combinations of therapies, and modulation of the tumor microenvironment with a specific focus on immunotherapy. Each of these realms holds great promise for the field going forward. A more streamlined structure for enrollment into clinical trials will be a crucial step in accelerating progress in this area.

Percutaneous Trigeminal Stimulation for Intractable Facial Pain: A Case Series.

BACKGROUND: Facial pain syndromes can be refractory to medical management and often need neurosurgical interventions. Neuromodulation techniques, including percutaneous trigeminal ganglion (TG) stimulation, are reversible and have emerged as alternative treatment options for intractable facial pain. OBJECTIVE: To report the complication rates and analgesic effects associated with TG stimulation and identify potential predictors for these outcomes. METHODS: A retrospective chart review of 59 patients with refractory facial pain who underwent TG stimulation was conducted. Outcomes following trial period and permanent stimulation were analyzed. Patients with >50% pain relief during trial stimulation received permanent implantation of the stimulation system. RESULTS: Successful trial stimulation was endorsed by 71.2% of patients. During the trial period, 1 TG lead erosion was identified. History of trauma (facial/head trauma and oral surgery) was the only predictor of a failed trial compared to pain of idiopathic etiology (odds ratio: 0.15; 95% CI: 0.03-0.66). Following permanent implantation, approximately 29.6% and 26.5% of patients were diagnosed with lead erosion and infection of the hardware, respectively. TG lead migrations occurred in 11.7% of the patients. The numeric rating scale score showed a statistically significant reduction of 2.49 (95% CI: 1.37-3.61; P = .0001) at an average of 10.8 mo following permanent implantation. CONCLUSION: TG stimulation is a feasible neuromodulatory approach for the treatment of intractable facial pain. Facial/head trauma and oral surgery may predict a nonsuccessful trial stimulation. Future development of specifically designed electrodes for stimulation of the TG, and solutions to reduce lead contamination are needed to mitigate the relatively high complication rate.

Glioneuronal Tumor With Features of Ganglioglioma and Neurocytoma Arising in the Fourth Ventricle: A Report of 2 Unusual Cases and a Review of Infratentorial Gangliogliomas.

Infratentorial glioneuronal neoplasms are overall quite rare and are more commonly low-grade with surgical excision usually being curative. Multiple distinct histologic entities have been described including rosette-forming glioneuronal tumor, papillary glioneuronal tumor, neurocytoma, dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease), cerebellar liponeurocytoma, and ganglioglioma. While each of these entities has distinct findings, in some instances a tumor may demonstrate overlapping histologic features with mixed components. Herein, we report 2 unusual adult cases of a fourth ventricular glioneuronal tumor with features of ganglioglioma and neurocytoma, with one coming from a surgical resection and one found incidentally at autopsy. To the best of our knowledge, this specific histologic combination has not previously been described. As such, the clinical significance is unknown although in both cases the neoplasms were circumscribed and appeared to be low grade. The presence of the gangliogliomatous component was of particular interest since these are extremely rare occurrences in the fourth ventricle and we provide a comprehensive review of infratentorial gangliogliomas.