Clinical and Computerized Volumetric Analysis of Posterior Fossa Decompression for Space-Occupying Cerebellar Infarction.

Background and Purpose: Surgical decompression of the posterior fossa is often performed in cases with a space-occupying cerebellar infarction to prevent coma and death. In this study, we analyzed our institutional experience with this condition. We specifically attempted to address timing issues and investigated the role of cerebellar necrosectomy using imaging data and conducting volumetric analyses. Methods: We retrospectively studied pertinent clinical and imaging data, including computerized volumetric analyses (preoperative/postoperative infarction volume, necrosectomy volume, and posterior fossa volume), from all 49 patients who underwent posterior fossa decompression surgery for cerebellar infarction in our department from January 2012 to January 2021. Results: Thirty-five (71%) patients had a Glasgow Coma Scale (GCS) of 14-15 at admission vs. only 14 (29%) before vs. 41 (84%) following surgery. Seven (14%) patients had preventive surgery (initial GCS 14-15, preoperative GCS change ≤ 1). Only 18 (37%) patients had an mRS score of 0-3 at discharge. Estimated overall survival was 70.5% at 1 year. Interestingly, 18/20 (90%) surviving cases had a modified Rankin Scale (mRS) outcome of 0-3 (mRS 0-2: 12/20 [60%]) 1 year after surgery. Surgical timing, including preventive surgery and mass effect of the infarct, in the posterior fossa assessed semi-quantitatively (Kirollos grade) and with volumetric parameters that were not predictive of the patients' (functional) outcomes. Conclusion: Posterior fossa decompression for cerebellar infarction is a life-saving procedure, but rapid recovery of the GCS after surgery does not necessarily translate into good functional outcome. Many patients died during follow-up, but long-term mRS outcomes of 4-5 are rare. Surgery should probably aim primarily at pressure relief, and our clinical as well as volumetric data suggest that the impact of removing an infarcted tissue may be limited. It is presumably relatively safe to initially withhold surgery in cases with a GCS of 14-15.

Microvascular Decompression of the VII/VIII Cranial Nerve Complex for the Treatment of Intermediate Nerve Neuralgia: A Retrospective Case Series.

BACKGROUND: Intermediate nerve neuralgia (INN) is a rare and often overlooked form of primary otalgia. The pathophysiological mechanism is unknown, although one of the possible contributing factors is a neurovascular conflict at the root entry zone of the intermediate nerve. The pain can be severely debilitating, and the palette of treatment options is small. OBJECTIVE: To assess the outcome of microvascular decompression (MVD) of the VII/VIII cranial nerve complex for treating INN. METHODS: We retrospectively reviewed the records of a group of 8 consecutive patients with INN who underwent MVD of the VII/VIII cranial nerve complex in the period 1994 to 2015. RESULTS: In total, 7 of the 8 patients experienced almost immediate and complete relief of pain, which remained at long-term follow-up (mean 35 mo ± 24 mo, range 8-84 mo). Postoperatively, 1 patient had a cerebrospinal fluid (CSF) leak, 3 patients experienced permanent ipsilateral hearing loss, and 3 patients had temporary complaints associated with excessive drainage of CSF. CONCLUSION: This study suggests MVD as a valid treatment for medically refractory INN. MVD carries surgical risk, but given the severity of complaints of these patients, we believe the treatment benefits outweigh the associated complications.

NKCC1 Regulates Migration Ability of Glioblastoma Cells by Modulation of Actin Dynamics and Interacting with Cofilin.

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults. The mechanisms that confer GBM cells their invasive behavior are poorly understood. The electroneutral Na+-K+-2Cl- co-transporter 1 (NKCC1) is an important cell volume regulator that participates in cell migration. We have shown that inhibition of NKCC1 in GBM cells leads to decreased cell migration, in vitro and in vivo. We now report on the role of NKCC1 on cytoskeletal dynamics. We show that GBM cells display a significant decrease in F-actin content upon NKCC1 knockdown (NKCC1-KD). To determine the potential actin-regulatory mechanisms affected by NKCC1 inhibition, we studied NKCC1 protein interactions. We found that NKCC1 interacts with the actin-regulating protein Cofilin-1 and can regulate its membrane localization. Finally, we analyzed whether NKCC1 could regulate the activity of the small Rho-GTPases RhoA and Rac1. We observed that the active forms of RhoA and Rac1 were decreased in NKCC1-KD cells. In summary, we report that NKCC1 regulates GBM cell migration by modulating the cytoskeleton through multiple targets including F-actin regulation through Cofilin-1 and RhoGTPase activity. Due to its essential role in cell migration NKCC1 may serve as a specific therapeutic target to decrease cell invasion in patients with primary brain cancer.