Questionnaire-Based Assessment of the Masticatory Function and Facial Nerve Recovery Post Pterional Approach in Brain Tumors Surgery

Background: The pterional approach for craniotomy, one of the most used surgical intervention in neurosurgery, results in a series of postoperative changes that, if they persist, affect the patient’s life, social reintegration, and his/her physical and mental recovery. The aim of the present study was to develop and validate a questionnaire for indicating directly affected masticatory muscles groups and facial nerve branches, in patients undergoing the pterional approach in neurosurgery, so that the recovery therapy can be monitored and personalized. Methods: A self-reporting questionnaire consisting of 18 items (12 for postoperative masticatory status and 6 for facial nerve branches involvement), validated on fifteen patients, following three steps: items development, scale development, and scale evaluation, was prospectively applied twice, at a one-year interval (T0 and T1), with thirty-two patients suffering from vascular or tumoral pathology and surgically treated through a pterional approach. Results: No statistically significant correlation could be found between postoperative outcomes and age or gender. Facial nerve branch involvement could not be correlated with any of the assessed variables. Pathology and time elapsed from surgery were statistically significantly correlated to preauricular pain on the non-operated side (p = 0.008 and p = 0.034, respectively). Time elapsed from surgery was statistically significantly correlated to the ability to chew hard food, pain while yawning, and preauricular pain during back and forward jaw movements and gradual mouth opening. Conclusions: We created and validated a valuable patient-centered questionnaire that can be employed as a tool for postoperative assessment of directly affected masticatory muscles and groups of facial nerve branches.

A Case Series of Intraneural Ganglion Cyst Involving the Common Peroneal Nerve: Potential Cause for Foot Drop

Background: Intraneural ganglion cysts (IGC) are non-neoplastic mucinous cysts that form when thick mucinous fluid accumulates in the epineurium of peripheral nerves, with the majority of cases occurring in the para-articular or articular areas. Case Presentation: The two cases of a 69-year-old man and a 59-year-old man who acquired peroneal nerve neuropathy as a result of an intraneural ganglion cyst are presented here. The L.L.R.M. Medical College Department of Orthopedics provided care for them. There was complete nerve recovery in all patients after substantial cyst wall dissection and secretion removal. Conclusion: An intraneural ganglion cyst and trauma may exacerbate nerve damage, despite the fact that it is difficult to detect the cyst before surgery. An early diagnosis and prophylactic actions are typically associated with better outcomes. KEY WORDS: Intraneural ganglion, Common peroneal nerve, Foot drop.

Nerve recovery from treatment with a vascularized nerve graft compared to an autologous non-vascularized nerve graft in animal models: A systematic review and meta-analysis

Background Treatment of nerve injuries proves to be a worldwide clinical challenge. Vascularized nerve grafts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous non-vascularized nerve graft. However, there is no adequate clinical evidence for the beneficial effect of vascularized nerve grafts and they are still disputed in clinical practice. Objective To systematically review whether vascularized nerve grafts give a superior nerve recovery compared to non-vascularized nerve autografts regarding histological and electrophysiological outcomes in animal models. Material and methods PubMed and Embase were systematically searched. The inclusion criteria were as follows: 1) the study was an original full paper which presented unique data; 2) a clear comparison between a vascularized and a non-vascularized autologous nerve transfer was made; 3) the population study were animals of all genders and ages. A standardized mean difference and 95% confidence intervals for each comparison was calculated to estimate the overall effect. Subgroup analyses were conducted on graft length, species and time frames. Results Fourteen articles were included in this review and all were included in the meta-analyses. A vascularized nerve graft resulted in a significantly larger diameter, higher nerve conduction velocity and axonal count compared to an autologous non-vascularized nerve graft. However, during sensitivity analysis the effect on axonal count disappeared. No significant difference was observed in muscle weight. Conclusion Treating a nerve gap with a vascularized graft results in superior nerve recovery compared to non-vascularized nerve autografts in terms of axon count, diameter and nerve conduction velocity. No difference in muscle weight was seen. However, this conclusion needs to be taken with some caution due to the inherent limitations of this meta-analysis. We recommend future studies to be performed under conditions more closely resembling human circumstances and to use long nerve defects.

SIRT6 inhibition delays peripheral nerve recovery by suppressing migration, phagocytosis and M2-polarization of macrophages

Background Silent information regulator 6 (SIRT6) is a mammalian homolog of the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin family. Prior evidences suggested that the anti-inflammatory function of SIRT6 after spinal cord and brain injury, and it plays a crucial role in macrophages polarization of adipose tissue and skin. However, the role of SIRT6 in macrophages involved peripheral nerve injury is still unknown. Given the prominent role of macrophages in peripheral nerve recovery, we aim to investigate the role of SIRT6 in the regulation of phenotypes shift and functions in macrophages after peripheral nerve injury. Results In the present study, we first identified a significant increase of SIRT6 expression during nerve degeneration and macrophages phagocytosis. Next, we found nerve recovery was delayed after SIRT6 silencing by injected shRNA lentivirus into the crushed sciatic nerve, which exhibited a reduced expression of myelin-related proteins (e.g., MAG and MBP), severer myoatrophy of target muscles, and inferior nerve conduction compared to the shRNA control injected mice. In vitro, we found that SIRT6 inhibition by being treated with a selective inhibitor OSS_128167 or lentivirus transfection impairs migration and phagocytosis capacity of bone marrow-derived macrophages (BMDM). In addition, SIRT6 expression was discovered to be reduced after M1 polarization, but SIRT6 was enhanced after M2 polarization in the monocyte-macrophage cell line RAW264.7 and BMDM. Moreover, SIRT6 inhibition increased M1 macrophage polarization with a concomitant decrease in M2 polarization both in RAW264.7 and BMDM via activating NF-κB and TNF-α expression, and SIRT6 activation by UBCS039 treatment could shift the macrophages from M1 to M2 phenotype. Conclusion Our findings indicate that SIRT6 inhibition impairs peripheral nerve repair through suppressing the migration, phagocytosis, and M2 polarization of macrophages. Therefore, SIRT6 may become a favorable therapeutic target for peripheral nerve injury.

Compound motor action potentials in transient and persistent phrenic nerve injury - metanalysis.

Background: The right phrenic nerve is vulnerable to injury (rPNI) during cryoballoon ablation (CBA) isolation of the right pulmonary veins. The complication can be transient or persistent. The reported incidence of rPNI fluctuates from 4.73% to 24.7% depending on changes over time, CBA-generation, and selected protective methods. Methods: Through September 2019, a database search was performed on MEDLINE, EMBASE, and Cochrane Database. In the selected articles, the references were also extensively searched. The study provides a comprehensive meta-analysis of the overall prevalence of rPNI, assesses the transient to persistent PNI-ratio, the outcome of using compound motor action potentials (CMAP), and estimated average time to nerve recovery. Results: From 2008 to 2019, 10,341 records from 48 trials were included. Out of 783 eighty- PNI (7.7%), 589 (5.7%) were transient, and 194 (1.9%) were persistent. CMAP caused a significant reduction in the risk of persistent PNI from 2.3% to 1.1% (p = 0.05; odds ratio [OR] 2.13) in all CBA groups. The mean time to rPNI recovery extended beyond the hospital discharge was significantly shorter in CMAP group at three months on average versus non CMAP at six months (p = 0.012). CMAP (in contrast to non-CMAP procedures) detects PNI earlier from 4 to 16 sec (p < 0.05; I2 = 74.53%) and 3 to 9º (p < 0.05; I2 = 97.24%) earlier. Conclusions: rPNI extending beyond hospitalization is a relatively rare complication. CMAP use causes a significant decrease in the risk of prolonged injury and shortens the time to recovery

Two-Dimensional Nanomaterials for Peripheral Nerve Engineering: Recent Advances and Potential Mechanisms

Peripheral nerve tissues possess the ability to regenerate within artificial nerve scaffolds, however, despite the advance of biomaterials that support nerve regeneration, the functional nerve recovery remains unsatisfactory. Importantly, the incorporation of two-dimensional nanomaterials has shown to significantly improve the therapeutic effect of conventional nerve scaffolds. In this review, we examine whether two-dimensional nanomaterials facilitate angiogenesis and thereby promote peripheral nerve regeneration. First, we summarize the major events occurring after peripheral nerve injury. Second, we discuss that the application of two-dimensional nanomaterials for peripheral nerve regeneration strategies by facilitating the formation of new vessels. Then, we analyze the mechanism that the newly-formed capillaries directionally and metabolically support neuronal regeneration. Finally, we prospect that the two-dimensional nanomaterials should be a potential solution to long range peripheral nerve defect. To further enhance the therapeutic effects of two-dimensional nanomaterial, strategies which help remedy the energy deficiency after peripheral nerve injury could be a viable solution.

Comparison of Functional Recovery of Infraorbital Nerve Paresthesia Following Open and Closed Reduction of Zygomaticomaxillary Complex Fractures

Objective: To compare the functional recovery of infraorbital nerve paresthesia following open reduction as compared to closed reduction in zygomaticomaxillary complex fracture management. Study Design: Randomized controlled trial. Place and Duration of Study: Oral and Maxillofacial Surgery Dept. Dentistry Section, Ayub Medical College & Teaching Hospital, Abbottabad from 1st April 2016 to 30th September 2016. Methodology: Eighty two patients of infraorbital nerve recovery were included. They were divided in two groups; group A was treated by closed reduction technique, and group B was treated by open reduction with internal fixation technique using mini plates. Permuted blocks of 6 were used to ensure equal representation in both groups. All patients were underwent surgical management within 1-7 days following trauma. Patients were assessed post-surgery for infraorbital nerve recovery. Results: There were 63.4% males and 36.6% females in group A while 60.9% males and 39.1% females were included in group B with mean age was 28.44±7.15 years in group A and 27.93±7.33 in group B respectively. 51.2% patients have infraorbial nerve recovery in group A while 65.8% have infraorbital nerve recovery in group B. Conclusion: Closed reduction approach was found to be the best reduction technique and open reduction was effective in terms of stability, prevention of relaps and functional recovery of infraorbital nerve injuries. Key words: Functional recovery, Infraorbital nerve, Paresthesia, Closed reduction, Zygomaticomaxillary complex fracture