Optimization of a Protocol for Isolating Cell-free DNA From Cerebrospinal Fluid.

A standardized protocol for the isolation of cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) is lacking. Therefore, we established a cfDNA isolation protocol optimized for clinical CSF specimens, integrating acceptable modifications and using artificial CSF generated from remnant CSF spiked with reference cell-free tumor DNA (ctDNA). We compared the isolation yields of in vitro diagnostic (IVD)-certified column-based (CB) and magnetic bead-based (MB) isolation. Furthermore, we modified both methods, including pre- and post-elution steps. To confirm ctDNA integrity and quantify the variant allele frequency after isolation, we performed droplet digital PCR (ddPCR) targeting IDH1 R132C in the reference ctDNA. MB isolation had a higher yield than CB isolation (P<0.0001), and post-isolation vacuum increased the final concentration in both methods, with little effect on cfDNA integrity. Our study provides a protocol to maximize CSF-ctDNA concentrations in IVD testing and future studies.

Preliminary Report of Fully Endoscopic Microvascular Decompression.

Objective: Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia (TN). But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. Methods: A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid (CSF) leakage, were also examined. Results: The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery (PICA) in 8 cases (32.0%), vertebral artery (VA) in 1 case (4.0%), tandem lesions involving the AICA and VA in 1 case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and 8 patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Conclusion: Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

Assessing the Suitability of Artificial Intelligence-Based Chatbots as Counseling Agents for Patients with Brain Tumor: A Comprehensive Survey Analysis.

OBJECTIVE: The internet, particularly social media, has become a popular resource for learning about health and investigating one's own health conditions. The development of artificial intelligence (AI) chatbots has been fueled by the increasing availability of digital health data and advances in natural language processing techniques. While these chatbots are more accessible than before, they sometimes fail to provide accurate information. METHODS: We used representative chatbots currently available (Chat Generative Pretrained Transformer-3.5, Bing Chat, and Google Bard) to answer questions commonly asked by brain tumor patients. The simulated situations with questions were made and selected by the brain tumor committee. These questions are commonly asked by brain tumor patients. The goal of the study was introduced to each chatbot, the situation was explained, and questions were asked. All responses were collected without modification. The answers were shown to the committee members, and they were asked to judge the responses while blinded to the type of chatbot. RESULTS: There was no significant difference in accuracy and communication ability among the 3 groups (P = 0.253, 0.090, respectively). For empathy, Bing Chat and Google Bard were superior to Chat Generative Pretrained Transformer (P = 0.004, 0.002, respectively). The purpose of this study was not to assess or verify the relative superiority of each chatbot. Instead, the aim was to identify the shortcomings and changes needed if AI chatbots are to be used for patient medical purposes. CONCLUSION: AI-based chatbots are a convenient way for patients and the general public to access medical information. Under such circumstances, medical professionals must ensure that the information provided to chatbot users is accurate and safe.

Strategy of stretched Coils: Insights from a single center experience.

OBJECTIVE: A stretched coil, characterized by excessive elongation within the parent artery during a coil embolization procedure, poses a significant risk of forming a thrombus. This study reports on cases of stretched coils spanning 16 years and discusses effective assessment methods and treatment strategies. METHOD: Retrospective analysis of the institutional database comprising 14 cases where stretched coils were observed during coil embolization procedures was conducted, starting from January 2007. RESULTS: Among the 14 cases, four involved coil embolization for subarachnoid hemorrhage due to ruptured aneurysm, while the remaining cases were unruptured aneurysms. Starting in 2017, vaso-computed tomography (vaso-CT) was employed in nine cases to evaluate the proximal end of the stretched coils. Reimplantation was performed in 3 cases. Among them, two cases were relieved by pushing the coil delivery wire or microwire, while one case underwent balloon-assisted reimplantation. The stretched coils were removed in three cases by pulling. A rescue gooseneck microsnare technique was applied in one case. The stent was fixed in five cases. In two cases, no additional procedures were performed. Thrombosis is a potential complication that occurred in three cases of stretched coils. CONCLUSION: Many studies have addressed coil stretching and introduced various rescue methods, but relying solely on angiography for diagnosis or applying an inappropriate rescue technique can lead to ischemic stroke. This study emphasized the importance of vaso-CT as a tool for accurately identifying the proximal end of a stretched coil. Additionally, we aimed to facilitate the selection of an appropriate rescue technique.