Functional outcomes in MRI-guided laser interstitial therapy for temporal lobe epilepsy: a systematic review and meta-analysis.

OBJECTIVE: The use of MRI-guided laser interstitial thermal therapy (MRgLITT) has emerged as a promising treatment option for patients with drug-resistant temporal lobe epilepsy (TLE). Although the minimally invasive approach holds promise as an effective treatment for achieving seizure freedom, a comprehensive review of its impact on functional outcomes is still warranted. To address this need, this review aims to summarize data pertaining to the functional and neurocognitive outcomes following MRgLITT for TLE. METHODS: Four primary electronic databases were screened following PRISMA guidelines by two independent reviewers. All functional data related to cognitive, behavioral, and emotional outcomes were gathered and analyzed as well as the neuropsychological tests issued to assess pre- and postoperative outcomes. The functional outcomes assessed were grouped into the 5 most common categories: verbal cognition, visual cognition, cognitive emotion, visual deficits, and other higher-order cognitive functioning. RESULTS: A total of 4184 studies were screened and ultimately 408 patients from 14 studies were included for analysis. Changes in functional areas were assessed by comparing pre- and postoperative scores across a comprehensive set of 31 different functional and cognitive assessments, and were tabulated as the percentage of patients whose status improved, declined, or was maintained, where possible. In verbal (n = 112) and visual (n = 42) cognition, the rates of patients experiencing a decline were 20.4% and 13.5%, respectively, and the rates of improvement were 24.9% and 16.7%, respectively. Other functional outcomes assessed, including cognitive emotion (n = 150), visual deficits (n = 325), and higher-order cognitive processes like attention/processing (n = 19), motor cognition (n = 18), and general executive function (n = 4), exhibited varying rates of decline, ranging from 10.5% to 25%. CONCLUSIONS: MRgLITT is an effective and minimally invasive surgical alternative treatment for TLE, but there is an observable impact on patient functioning and cognitive status. This review demonstrates the need for standardized methods that can accurately capture and quantify the associated risk of MRgLITT to optimize its effect on patient quality of life moving forward.

Magnetic Resonance Imaging-Guided Laser Interstitial Therapy for In-Field Recurrence After Stereotactic Radiosurgery: Is Complete Ablation Required for Local Control?

BACKGROUND: Magnetic resonance imaging-guided laser interstitial therapy (MrLITT) presents a new valuable treatment alternative when the in-field recurrence (IFR) of metastatic brain tumors is difficult to safely access with open surgery or maximum radiation therapy has already been completed. OBJECTIVE: To examine the effects of MrLITT on longevity outcomes based on volume of ablation. METHODS: A retrospective study was carried out of 35 patients treated with MrLITT for IFR after radiosurgery for metastatic brain tumors at a single institution from 2010 to 2016. Overall survival (OS) and progression-free survival (PFS) were analyzed with Kaplan-Meier and Cox regression analyses according to ablation volume. Univariate and multivariate analyses further assessed risk factors based on ablation volume. RESULTS: Kaplan-Meier analyses showed no significant differences between total and subtotal ablation groups in OS (61.1 vs. 49.7 weeks) and PFS (45.1 and 42.7 weeks), respectively (P > 0.05). In the subtotal ablation group, independent risk factors included preoperative tumor volume (hazard ratio [HR], 1.24; P = 0.05) for OS and residual tumor volume (HR, 2.62; P = 0.01) for PFS. Multivariate Cox regressions suggested no significant differences in OS (HR, 1.03; P = 0.19) and PFS (HR, 1.02; P = 0.24) between total and subtotal ablation groups, whereas preoperative tumor volume remained a risk factor for decreased OS (HR, 1.23; P = 0.004). CONCLUSIONS: MrLITT is an effective treatment option for IFR after radiosurgery for metastatic brain tumors. The benefits of more aggressive gross total ablations of deep targets near eloquent cortices are limited compared with effective subtotal ablations, but the amount of residual tumor volume left must be appropriately balanced.

Examining the benefits of extended reality in neurosurgery: A systematic review.

While well-established in other surgical subspecialties, the benefits of extended reality, consisting of virtual reality (VR), augmented reality (AR), and mixed reality (MR) technologies, remains underexplored in neurosurgery despite its increasing utilization. To address this gap, we conducted a systematic review of the effects of extended reality (XR) in neurosurgery with an emphasis on the perioperative period, to provide a guide for future clinical optimization. Seven primary electronic databases were screened following guidelines outlined by PRISMA and the Institute of Medicine. Reported data related to outcomes in the perioperative period and resident training were all examined, and a focused analysis of studies reporting controlled, clinical outcomes was completed. After removal of duplicates, 2548 studies were screened with 116 studies reporting measurable effects of XR in neurosurgery. The majority (82%) included cranial based applications related to tumor surgery with 34% showing improved resection rates and functional outcomes. A rise in high-quality studies was identified from 2017 to 2020 compared to all previous years (p = 0.004). Primary users of the technology were: 56% neurosurgeon (n = 65), 28% residents (n = 33) and 5% patients (n = 6). A final synthesis was conducted on 10 controlled studies reporting patient outcomes. XR technologies have demonstrated benefits in preoperative planning and multimodal neuronavigation especially for tumor surgery. However, few studies have reported patient outcomes in a controlled design demonstrating a need for higher quality data. XR platforms offer several advantages to improve patient outcomes and specifically, the patient experience for neurosurgery.

Incidental Brain Tumors in the Pediatric Population: A Systematic Review and Reappraisal of Literature.

OBJECTIVES: Management of incidental asymptomatic brain tumors in children is controversial due to lack of clear evidence-based guidelines. We present this systematic review in an attempt to highlight an optimal treatment paradigm. METHODS: This systematic review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Databases were searched up to August 2019 using the keywords "incidental," "brain tumor," and "pediatric." Our main focus was on brain lesions suspected for neoplasm, diagnosed incidentally on neuroimaging in an otherwise asymptomatic patient <18 years old. Cystic, vascular, and inflammatory brain lesions were excluded. RESULTS: Fourteen studies comprising 308 patients were included. All cases were diagnosed using magnetic resonance imaging. The most common indications for imaging were headache (93; 30%) and trauma (72; 23%). Lesion distribution was supratentorial (179; 58%), infratentorial (121; 40%), and intraventricular (8; 3%). Of 308 cases, 243 (79%) were managed with neuroradiological surveillance and 57 (19%) by upfront surgical excision. Of those managed conservatively, 177 (73%) remained stable within a mean follow-up of 30 months, 54 (22%) progressed, and 12 (5%) spontaneously regressed. Meanwhile, upfront excision achieved complete remission in all 57 cases over a mean follow-up of 68.3 months. CONCLUSION: A small body of evidence has emerged, highlighting the marked heterogeneity and contradictory results between the available studies, limiting our ability to draw solid conclusions. At this point, the decision between surgery and "watchful waiting" should be tailored on an individual patient basis depending on suspicion of malignancy, clinical or radiologic progression, and parental preference.

Resection of a posterior fossa arteriovenous malformation complicated by leaked Onyx: a case report and review of literature.

Extravasation of Onyx is a rare complication during embolization of arteriovenous malformations (AVM). We present a case of embolization that was complicated by leakage of Onyx into the cerebellum which was later encountered during surgical excision of the AVM. Our goal is to report this rare event and to outline successful treatment of this complication. The patient's records were reviewed for medical history, laboratory and radiologic workup, and outpatient clinical follow-up. A 62-year-old female presented with Hunt Hess grade 2 and modified Fisher grade 2 subarachnoid hemorrhage (SAH) secondary to ruptured left posterior inferior cerebellar artery (PICA) aneurysm associated with a superior cerebellar vermian AVM. Following endovascular intervention, the aneurysm was completely embolized; however, only 75% of the AVM could be safely obliterated. Extravasation of Onyx from the ruptured aneurysm was noted on her initial angiogram. Elective suboccipital craniectomy was subsequently planned for resection of the residual AVM where the extravasated Onyx posed an operative nuisance during resection. Post-op angiogram confirmed complete resection of the AVM, as well as the bulk of the extravasated Onyx. Patient did well post-operatively, remaining neurologically intact throughout her hospital course. Although infrequently reported in the literature, Onyx extravasation is a potential complication that neurosurgeons should be ready to face. Adherence of Onyx to surrounding parenchyma could hinder optimal surgical resection of AVM and increase complications. Therefore, careful surgical dissection should be performed with special care to delicate neurovasculature. In this case, complete resection of the AVM and Onyx mass was safely achieved.

Efficacy and safety of gamma knife radiosurgery for posterior cranial fossa meningioma: a systematic review.

The management of posterior cranial fossa meningioma [PCFM] is challenging and many neurosurgeons advise gamma knife radiosurgery [GKRS] as a modality for its upfront or adjuvant treatment. Due to the varying radiosurgical response based on lesion location, tumor biology, and radiation dosage, we performed a pioneer attempt in doing a systematic review analyzing the treatment efficacy and safety profile of GKRS for PCFM based on current literature. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses [PRISMA] guidelines. A thorough literature search was conducted on PubMed, Web of science, and Cochrane data base; articles were selected systematically based on PRISMA protocol, reviewed completely, and relevant data was summarized and discussed. A total of 18 publications pertaining to GKRS for PCFM were included with a pooled sample size of 2131 patients. The median pre-GKRS tumor volume ranged from 2.28 to 10.5 cm [3]. Primary GKRS was administered in 61.1% of the pooled study cohorts, adjuvant treatment in 32.9%, and salvage therapy in 6.5% patients. Majority of the meningiomas were WHO grade 1 tumors (99.7%). The pooled mean marginal dose in the studies was 13.6 Gy (range 12-15.2 Gy) while the mean of maximum doses was 28.6 Gy (range 25-35 Gy). Most studies report an excellent radiosurgical outcome including the tumor control rate and the progression-free survival [PFS] of over 90%. The tumor control, PFS, and adverse radiation effect [ARE] rates in author's series were 92.3%, 91%, and 9.6%, respectively. The favorable radiosurgical outcome depends on multiple factors such as small tumor volume, absence of previous radiotherapy, tumor location, elderly patients, female gender, longer time from symptom onset, and decreasing maximal dose. GKRS as primary or adjuvant treatment modality needs to be considered as a promising management strategy for PCFM in selected patients in view of the growing evidence of high tumor control rate, improved neurological functions, and low incidence of ARE. The use of multiple isocenters, 3-D image planning, and limit GKRS treatment to tumors less than 3.5 cm help to avoid complications and achieve the best results. The treatment decisions in PCFM cases must be tailored and should consider the factors such as radiological profile, symptom severity, performance level, and patient preference for a good outcome.

The Origins of Eponymous Aneurysm Clips: A Review.

Aneurysm clips are indispensable tools in the armamentarium of vascular neurosurgeons. The history of the development of aneurysm clips is witness to ingenuity and tenacity in treating a potentially devastating disease. Few know the stories of their innovators and the inspiration behind their designs. Hence, we present this historical vignette in an attempt to shed more light on the pioneers who shaped the evolution of aneurysm clips as we know them. A comprehensive literature search was performed using PubMed, Google Scholar, Google Books, and library historical archives, as well as personal communications with relatives, colleagues, and institutions of the surgeon-designers. We present the following aneurysm clip innovators and chronicle their biographies and contributions: Herbert Olivecrona (1891-1980), Frank Mayfield (1908-1991), Charles Drake (1920-1998), Joseph McFadden (1920-present), Thoralf Sundt Jr. (1930-1992), William M. Lougheed (1923-2004), William B. Scoville (1906-1984), Milton D. Heifetz (1921-2015), Gazi Yasargil (1925-present), Kenichiro Sugita (1932-1994), and Robert Spetzler (1944-present). Although this compilation of eponymous clips is by no means complete, we hope that it provides an informative historical perspective and an inspiration for aspiring neurosurgeons. The history of aneurysm surgery, an entity once deemed inoperable, teaches us the importance of innovation in medicine.

Nocardia amikacinitolerans and cytomegalovirus: distinctive clinical and radiological characterization of the rare etiologies of brain abscesses: report of 2 cases.

Central nervous system infections in immunosuppressed patients are rare but potentially lethal complications that require swift diagnoses and intervention. While the differential diagnosis for new lesions on neuroradiological imaging of immunosuppressed patients typically includes infections and neoplasms, image-based heuristics to differentiate the two has been shown to have variable reliability.The authors describe 2 rare CNS infections in immunocompromised patients with atypical physical and radiological presentations. In the first case, a 59-year-old man, who had recently undergone a renal transplantation, was found to have multifocal Nocardia amikacinitolerans abscesses masquerading as neoplasms on diffusion-weighted imaging (DWI); in the second case, a 33-year-old man with suspected recurrent Hodgkin's lymphoma was found to have a nonpyogenic abscess with cytomegalovirus (CMV) encephalitis.As per review of the literature, this appears to be the first case of brain abscess caused by N. amikacinitolerans, a recently isolated superbug. Despite confirmation through brain biopsy later on in case 1, the initial radiological appearance was atypical, showing subtle diffusion restriction on DWI. Similarly, the authors present a case of CMV encephalitis that presented as a ring-enhancing lesion, which is extremely rare. Both cases draw attention to the reliability of neuroimaging in differentiating an abscess from a neoplasm.