Intraoperative Awakening from Endotracheal General Anesthesia for Brain Mapping with Tracheal Tube In Situ

Awake craniotomy (AC) is indicated to excise a lesion close to an eloquent area of the brain. Success of this procedure depends upon the patient’s active participation during the awake phase of the surgery, especially for brain mapping. Occasionally, a patient may refuse to remain awake during the surgical procedure and demand general anesthesia (GA). A 27-year-old male with uncontrolled seizures from recurrent brain tumor near motor area refused to consent for AC citing his past unpleasant experience; so, the decision to administer GA was taken. To avoid straining/coughing on tracheal tube, his airway was anesthetized with transtracheal xylocaine, bilateral superior laryngeal nerve block, and inflation of tracheal tube cuff with xylocaine. GA was maintained with sevoflurane, infusion of fentanyl, and rocuronium. To awaken him, anesthetics were discontinued and rocuronium antagonized with sugammadex. Intravenous lignocaine and midazolam were administered to supress cough reflex and produce amnesia, respectively. He tolerated the entire duration of 30 minutes of brain mapping with electrocorticography and neurological testing comfortably. Upon completion of brain mapping, GA was reintroduced and the lesion excised. The surgical outcome was good with no neurological deficit. When interviewed postoperatively, the patient had no recall of the awake phase.

Distinct Role of CD11b+Ly6G−Ly6C− Myeloid-Derived Cells on the Progression of the Primary Tumor and Therapy-Associated Recurrent Brain Tumor

Myeloid-derived cells have been implicated as playing essential roles in cancer therapy, particularly in cancer immunotherapy. Most studies have focused on either CD11b+Ly6G+Ly6C+ granulocytic or polymorphonuclear myeloid-derived suppressor cells (G-MDSCs or PMN-MDSCs) or CD11b+Ly6G−Ly6C+ monocytic MDSCs (M-MDSCs), for which clear roles have been established. On the other hand, CD11b+Ly6G−Ly6C− myeloid-derived cells (MDCs) have been less well studied. Here, the CD11b-diphtheria toxin receptor (CD11b-DTR) transgenic mouse model was used to evaluate the role of CD11b+ myeloid-derived cells in chemotherapy for an orthotopic murine astrocytoma, ALTS1C1. Using this transgenic mouse model, two injections of diphtheria toxin (DT) could effectively deplete CD11b+Ly6G−Ly6C− MDCs while leaving CD11b+Ly6G+Ly6C+ PMN-MDSCs and CD11b+Ly6G−Ly6C+ M-MDSCs intact. Depletion of CD11b+Ly6G−Ly6C− MDCs in mice bearing ALTS1C1-tk tumors and receiving ganciclovir (GCV) prolonged the mean survival time for mice from 30.7 to 37.8 days, but not the controls, while the effectiveness of temozolomide was enhanced. Mechanistically, depletion of CD11b+Ly6G−Ly6C− MDCs blunted therapy-induced increases in tumor-associated macrophages (TAMs) and compromised therapy-elicited angiogenesis. Collectively, our findings suggest that CD11b+Ly6G−Ly6C− MDCs could be manipulated to enhance the efficacy of chemotherapy for brain tumors. However, our study also cautions that the timing of any MDC manipulation may be critical to achieve the best therapeutic result.

11C-methionine-PET for differentiating recurrent brain tumor from radiation necrosis: radiomics approach with random forest classifier

Differentiating recurrent brain tumor from radiation necrosis is often difficult. This study aims to investigate the efficacy of 11C-methionine (MET)-PET radiomics for distinguishing recurrent brain tumor from radiation necrosis, as compared with conventional tumor-to-normal cortex (T/N) ratio evaluation. We enrolled 41 patients with metastatic brain tumor or glioma treated using radiation therapy who underwent MET-PET. The area with a standardized uptake value > 1.3 times that of the normal brain cortex was contoured. Forty-two PET features were extracted and used in a random forest classifier and the diagnostic performance was evaluated using a 10-fold cross-validation scheme. Gini index was measured to identify relevant PET parameters for classification. The reference standard was surgical histopathological analysis or more than 6 months of follow-up with MRI. Forty-four lesions were used for the analysis. Thirty-three and 11 lesions were confirmed as recurrent brain tumor and radiation necrosis, respectively. Radiomics and T/N ratio evaluation showed sensitivities of 90.1% and 60.6%, and specificities of 93.9% and 72.7% with areas under the curve of 0.98 and 0.73, respectively. Gray level co-occurrence matrix dissimilarity was the most pertinent feature for diagnosis. MET-PET radiomics yielded excellent outcome for differentiating recurrent brain tumor from radiation necrosis, which outperformed T/N ratio evaluation.

Reversible Valproate Induced Pisa Syndrome and Parkinsonism in a Neuro-Oncology Patient with Depression and Epilepsy

Neurological and psychiatric conditions frequently overlap in neuro-oncology. This overlapping negatively affects patients’ quality of life and decreases the ability of providers to manage specific symptoms by therapy modulation, especially when psychopharmacotherapy needs to be prescribed. We describe here a patient with recurrent brain tumor, symptomatic epilepsy and depression who developed Pisa syndrome and parkinsonism after several months of valproic acid use. An accurate recognition of symptoms and treatment side effect allowed an appropriate clinical approach so as to rapidly improve both movement disorder and depression without increasing the risk of developing seizure. This has improved the autonomy and quality of life in a patient with poor prognosis.