Gharibi Loron, Ali

Abstract Background Cerebrospinal fluid cell-free DNA (cfDNA) can detect and monitor leptomeningeal disease but has not been previously used to monitor parenchymal lesions. Methods Herein, we report our initial experience with CSF cfDNA monitoring for 2 patients with colorectal cancer (CRC) metastases to the thalamus, causing obstructive hydrocephalus. Results CSF samples were obtained during ventriculoperitoneal shunt placement, demonstrating high levels of cfDNA in both cases. Several genomic alterations detected in the cfDNA sequencing matched those in the tumor tissue biopsy. Follow-up CSF evaluations after subsequent therapy were used to help adjudicate pseudo-progression versus true progression. Conclusions Neither patient developed leptomeningeal disease, demonstrating CSF’s utility in evaluating solitary brain metastases in direct contact with a CSF compartment.

BACKGROUND Posttraumatic retroclival hematomas are rare pathologies among pediatric patients and can result in cranial nerve palsies. The authors sought to survey the literature and characterize the risk factors, treatment considerations, and overall outcomes for pediatric patients experiencing posttraumatic retroclival hematomas. OBSERVATIONS A search of the Ovid Embase, Scopus, PubMed, and Web of Science databases from January 1986 to May 2024 was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Additionally, the authors report a novel case of pediatric retroclival hematoma. The systematic review identified 41 eligible articles describing 64 individual cases of posttraumatic clival/retroclival hematoma in pediatric patients. The incidence of abducens nerve palsy in the setting of posttraumatic retroclival hematoma was 40%, and the rate of complete recovery of abducens nerve function was 73%. Analyses revealed that a higher initial Glasgow Coma Scale (GCS) score correlated with general neurological recovery (p < 0.05). However, no significant difference was found in GCS scores between patients with complete and those with incomplete abducens nerve recovery. LESSONS There is a high rate of spontaneous recovery of abducens nerve function in patients with abducens palsy in the setting of posttraumatic retroclival hematoma. While initial GCS scores can predict general neurological recovery, factors influencing abducens nerve palsy resolution remain unclear. https://thejns.org/doi/10.3171/CASE24474

BACKGROUND The management of cystic brain metastases remains challenging, with high recurrence rates following treatment with resection and/or stereotactic radiosurgery (SRS). Tumor resection and adjuvant radiation provide superior outcomes in comparison to those for each therapy alone, but large cystic tumor en bloc removal is difficult. Cyst aspiration can be used to decrease the radiation target volume, enabling safer delivery of a therapeutic radiation dose with improved local tumor control. However, cysts can rapidly recur following aspiration. Herein, the authors present a case in which cyst aspiration, radiation, and resection were combined within a single procedure. OBSERVATIONS During a single anesthesia episode, a 70-year-old female underwent stereotactic cyst aspiration, single-fraction SRS, and resection of a 3.7-cm cystic temporal lobe breast metastasis. The lesion volume exceeded 40 cm 3 before cyst aspiration, decreasing by 62.5% afterward. LESSONS Definitive management of large cystic brain metastases including aspiration, radiation, and resection is feasible under a single anesthesia session. This approach, compared to traditional management, could help minimize challenges associated with large cystic lesions, including recurrence and/or radiation necrosis. https://thejns.org/doi/10.3171/CASE24357

Aberrant metabolism is a hallmark of malignancies including gliomas. Intracranial microdialysis enables the longitudinal collection of extracellular metabolites within CNS tissues including gliomas and can be leveraged to evaluate changes in the CNS microenvironment over a period of days. However, delayed metabolic impacts of CNS injury from catheter placement could represent an important covariate for interpreting the pharmacodynamic impacts of candidate therapies. Intracranial microdialysis was performed in patient-derived glioma xenografts of glioma before and 72 h after systemic treatment with either temozolomide (TMZ) or a vehicle. Microdialysate from GBM164, an IDH-mutant glioma patient-derived xenograft, revealed a distinct metabolic signature relative to the brain that recapitulated the metabolic features observed in human glioma microdialysate. Unexpectedly, catheter insertion into the brains of non-tumor-bearing animals triggered metabolic changes that were significantly enriched for the extracellular metabolome of glioma itself. TMZ administration attenuated this resemblance. The human glioma microdialysate was significantly enriched for both the PDX versus brain signature in mice and the induced metabolome of catheter placement within the murine control brain. These data illustrate the feasibility of microdialysis to identify and monitor the extracellular metabolome of diseased versus relatively normal brains while highlighting the similarity between the extracellular metabolome of human gliomas and that of CNS injury.

Abstract Background Bevacizumab is commonly used to manage cerebral edema associated with brain tumors. However, its long half-life poses challenges for patients requiring urgent surgery due to wound complications. We present a case of utilizing therapeutic plasma exchange (TPE) to remove bevacizumab in a patient with recurrent glioblastoma requiring urgent surgery. Methods A 58-year-old male with recurrent glioblastoma, IDH-wildtype, presented with clinical and radiographic concern for ventriculitis requiring urgent wound washout only 4 days after his last bevacizumab infusion. TPE was performed for 3 sessions after surgery using a centrifugation-based cell separator. Replacement fluids included normal serum albumin, normal saline, and fresh frozen plasma. Bevacizumab levels were quantified using an enzyme-linked immunoabsorbent assay before and after each TPE session. Results TPE effectively removed bevacizumab, enabling safe surgery without new complications. Plasma bevacizumab levels decreased from 1087.63 to 145.35 ng/mL (13.4% of original) by the end of the last TPE session. This decline is consistent with nearly 3 half-lives, which compares favorably to the expected timeline of natural decline given the 21-day half-life. Conclusions We report a complex clinical scenario of a patient requiring urgent wound washout 4 days after last bevacizumab infusion for CNS infection. Surgery was successfully performed without new complications with use of TPE to remove bevacizumab immediately following surgery. This case highlights the feasibility of this approach, which may be utilized effectively in patients requiring surgery after having recently received bevacizumab.