Functional outcomes after resection of middle frontal gyrus diffuse gliomas

A frontal cortical network is critical for language planning during spoken interaction

Many brain areas exhibit activity correlated with language planning, but the impact of these dynamics on spoken interaction remains unclear. Here we use direct electrical stimulation to transiently perturb cortical function in neurosurgical patient-volunteers performing a question-answer task. Stimulating structures involved in speech motor function evoked diverse articulatory deficits, while perturbations of caudal inferior and middle frontal gyri - which exhibit preparatory activity during conversational turn-taking - led to response errors. Perturbation of the same planning-related frontal regions slowed inter-speaker timing, while faster responses could result from stimulation of sites located in other areas. Taken together, these findings further indicate that caudal inferior and middle frontal gyri constitute a critical planning network essential for interactive language use.

The Impact of Endoscopic Endonasal Surgery on Quality of Life in Patients with Malignant Tumors of the Anterior Skull Base: A Prospective Study

Objective

To investigate the effects of endoscopic endonasal surgery (EES) on longitudinal quality of life (QoL) in patients with malignant tumors of the anterior skull base.

Methods

Eligible patients prospectively completed the Anterior Skull Base Surgery Questionnaire (ASBQ) and the 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaires in referring to 3 different periods throughout their treatment and recovery.

Results

Forty patients were included. The median volume coronal maximum length of the tumor was 3.6 cm (95% CI 2.7-4.1cm). Overall QoL significantly worsened at 1 month postoperatively but returned to baseline after 1 year. Unrelieved symptoms in specific domains prompted further evaluation of individual items. Transient worsening of taste (p=0.011) and olfaction (p=0.004) lasted for 1 month but gradually relieved within the first postoperative year, but vision consistently worsened over the course of the treatment (p=0.126). Age>50 years (p<0.001), comorbidities (p<0.001), tumor necrosis (p<0.001) and recurrence (p=0.001) were associated with worse preoperative QoL. Poor long-term QoL was noted in those undergoing adjuvant therapy (p=0.032). Overall ASBQ scores (p=0.024), subdomain scores in specific symptoms (p=0.016), and vision scores (p=0.009) were worse only in patients with the greater coronal maximum diameter at 1-month postoperatively. Greater coronal maximum diameter was related to worse preoperative subdomain scores regarding specific symptoms (p=0.030) and decreased postoperative long-term decreased vision scores (p=0.014).

Conclusion

Long-term site-specific and sinonasal QoL eventually stabilized after EES. Greater coronal maximum diameter was significantly associated with worsened vision function. Temporarily worse olfactory, vision, and taste function may be tied to decreased short-term QoL.

Intraoperative detection of IDH-mutant glioma using fluorescence lifetime imaging

Identifying isocitrate dehydrogenase (IDH)-mutation and glioma subtype during surgery instead of days later can aid in modifying tumor resection strategies for better survival outcomes. We report intraoperative identification of IDH-mutant glioma (N = 12 patients) with a clinically compatible fluorescence lifetime imaging (FLIm) device (excitation: 355 nm; emission spectral bands: 390/40 nm, 470/28 nm, 542/50 nm). The fluorescence-derived parameters were analyzed to study the optical contrast between IDH-mutant tumors and surrounding brain tissue. IDH-mutant oligodendrogliomas exhibited shorter lifetimes (3.3 ± 0.1 ns) than IDH-mutant astrocytomas (4.1 ± 0.1 ns). Both IDH-mutant glioma subtypes had shorter lifetimes than white matter (4.6 ± 0.4 ns) but had comparable lifetimes to cortex. Lifetimes also increased with malignancy grade within IDH-mutant oligodendrogliomas (grade 2: 2.96 ± 0.08 ns, grade 3: 3.4 ± 0.3 ns) but not within IDH-mutant astrocytomas. The current results support the feasibility of FLIm as a surgical adjuvant for identifying IDH-mutant glioma tissue.

Ventricular opening and cerebrospinal fluid circulation accelerate the biodegradation process of carmustine wafers suggesting their immunomodulation potential in the human brain

PURPOSE

Opening the ventricular system during glioblastoma surgery is often necessary, but the consequent effect on the tumor microenvironment of glioblastoma remains unknown. Implantation of carmustine wafer enables direct drug delivery to the tumor site; however, the exact mechanism of the wafer's biodegradation process is unclear, and the available data is limited to in vivo non-human mammalian studies. We hypothesized that the ventricular opening affects the degradation process of the wafer and the glioblastoma tumor microenvironment.

METHODS

This study included 30 glioblastoma patients. 21 patients underwent carmustine wafer implantation during initial surgery. All patients underwent repeated surgical resection upon recurrence, allowing for pathological comparison of changes associated with wafer implantation. Immunohistochemical analyses were performed using CD68, TMEM119, CD163, IBA1, BIN1, and CD31 antibodies to highlight microglia, macrophages, and tumor vascularity, and the quantitative scoring results were correlated with clinical, molecular, and surgical variables, including the effect of the ventricular opening.

RESULTS

The carmustine wafer implanted group presented significantly less TMEM119-positive microglia within the tumor (P = 0.0002). Simple and multiple regression analyses revealed that the decrease in TMEM119-positive microglia was correlated with longer intervals between surgeries and opened ventricular systems. No correlation was observed between age, methylated O6-methylguanine DNA methyltransferase promoter expression, and the extent of surgical resection.

CONCLUSIONS

Our study findings strongly suggest that biomaterials may possess immunomodulation capacity, which is significantly impacted by the ventricular opening procedure. Furthermore, our data highlights the pathophysiological effects of the ventricular opening within the surrounding human brain, especially after the wafer implantation.