Traumatic peripheral nerve injuries: a classification proposal.

BACKGROUND: Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery. MATERIALS: The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities. RESULTS: An alphanumeric code was produced, similar to that used in the AO classification of fractures. CONCLUSIONS: The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach. LEVEL OF EVIDENCE: according to the Oxford 2011 level of evidence, level 2.

Mesenchymal Stem Cell Treatment Perspectives in Peripheral Nerve Regeneration: Systematic Review.

Traumatic peripheral nerve lesions affect hundreds of thousands of patients every year; their consequences are life-altering and often devastating and cause alterations in movement and sensitivity. Spontaneous peripheral nerve recovery is often inadequate. In this context, nowadays, cell therapy represents one of the most innovative approaches in the field of nerve repair therapies. The purpose of this systematic review is to discuss the features of different types of mesenchymal stem cells (MSCs) relevant for peripheral nerve regeneration after nerve injury. The published literature was reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A combination of the keywords "nerve regeneration", "stem cells", "peripheral nerve injury", "rat", and "human" were used. Additionally, a "MeSH" research was performed in PubMed using the terms "stem cells" and "nerve regeneration". The characteristics of the most widely used MSCs, their paracrine potential, targeted stimulation, and differentiation potentials into Schwann-like and neuronal-like cells are described in this paper. Considering their ability to support and stimulate axonal growth, their remarkable paracrine activity, their presumed differentiation potential, their extremely low immunogenicity, and their high survival rate after transplantation, ADSCs appear to be the most suitable and promising MSCs for the recovery of peripheral nerve lesion. Clinical considerations are finally reported.

Principles of Cortical Plasticity in Peripheral Nerve Surgery.

Cortical plasticity is a finely regulated process that allows the central nervous system (CNS) to change in response to internal and external stimuli. While these modifications occur throughout normal brain development, interestingly, they are also elicited after peripheral nerve injury and surgery. This article provides an overview of the principle mechanisms of synaptic, neuronal, cortical and subcortical neuroplasticity, with special attention to cortical and subcortical modifications-as suggested by modern neuroimaging techniques-after peripheral nerve surgery. The main nerve transfer techniques for the superior extremities and their effect on cortical plasticity are also described.

Biopsy of the anterior interosseous motor branch for the pronator quadratus muscle: a safe and minimally invasive diagnostic tool for peripheral neuropathies. Anatomical surgery and surgical technique.

BACKGROUND AND OBJECTIVES: Choosing the correct site for a nerve biopsy remains a challenge due to nerve sacrifice and major donor site complications, such as neuroma, as seen in sural nerve biopsy. Selecting a deeper donor nerve can help in burying nerve stumps in deep soft tissues, preventing neuroma. Moreover, using an expendable, deeply situated motor nerve can aid indiagnosis when a motor neuropathy is suspected. The authors propose using the pronator quadratus (PQ) branch for this purpose, as it is located deep between the bellies of the flexor muscles and the interosseous membrane in the forearm. This branch is expendable since the denervation of the PQ has a negligible effect on forearm pronation, which is primarily sustained by the pronator teres. METHODS: The surgical approach is the same as the approach for anterior interosseous nerve transfer to the motor component of the ulnar nerve in the distal forearm: access is in the midline in the middle third of the forearm under local anesthesia Blunt dissection is performed, separating and retracting the flexor musculotendinous junction to reach the interosseous membrane where the PQ branch is identified. A careful dissection of the nerve branch is performed, allowing a 2 cm long segment to be cut and removed. The proximal stump is then buried into an adjacent muscle belly and the surgical site is closed. RESULTS: The technique is safe and reproducible in experienced hands. CONCLUSION: This technique may be especially applicable in cases where neurologists need to study motor neuropathies. Contraindications of the technique include wrist instability and high median nerve palsies.

Virtual-Augmented Reality and Life-Like Neurosurgical Simulator for Training: First Evaluation of a Hands-On Experience for Residents.

Background: In the recent years, growing interest in simulation-based surgical education has led to various practical alternatives for medical training. More recently, courses based on virtual reality (VR) and three-dimensional (3D)-printed models are available. In this paper, a hybrid (virtual and physical) neurosurgical simulator has been validated, equipped with augmented reality (AR) capabilities that can be used repeatedly to increase familiarity and improve the technical skills in human brain anatomy and neurosurgical approaches. Methods: The neurosurgical simulator used in this study (UpSurgeOn Box, UpSurgeOn Srl, Assago, Milan) combines a virtual component and a physical component with an intermediate step to provide a hybrid solution. A first reported and evaluated practical experience on the anatomical 3D-printed model has been conducted with a total of 30 residents in neurosurgery. The residents had the possibility to choose a specific approach, focus on the correct patient positioning, and go over the chosen approach step-by-step, interacting with the model through AR application. Next, each practical surgical step on the 3D model was timed and qualitatively evaluated by 3 senior neurosurgeons. Quality and usability-grade surveys were filled out by participants. Results: More than 89% of the residents assessed that the application and the AR simulator were very helpful in improving the orientation skills during neurosurgical approaches. Indeed, 89.3% of participants found brain and skull anatomy highly realistic during their tasks. Moreover, workshop exercises were considered useful in increasing the competency and technical skills required in the operating room by 85.8 and 84.7% of residents, respectively. Data collected confirmed that the anatomical model and its application were intuitive, well-integrated, and easy to use. Conclusion: The hybrid AR and 3D-printed neurosurgical simulator could be a valid tool for neurosurgical training, capable of enhancing personal technical skills and competence. In addition, it could be easy to imagine how patient safety would increase and healthcare costs would be reduced, even if more studies are needed to investigate these aspects. The integration of simulators for training in neurosurgery as preparatory steps for the operating room should be recommended and further investigated given their huge potential.

Modified constraint induced movement therapy in children with obstetric brachial plexus palsy: a systematic review.

INTRODUCTION: Obstetric brachial plexus palsy (OBPP) is a flaccid paralysis occurring in the upper limb during birth. The OBPP includes mild lesions with complete spontaneous recovery and severe injuries with no regain of arm function. Among the most promising rehabilitation treatments aimed at improving upper extremity motor activities in individuals with neurological dysfunctions, there is the modified constraint-induced movement therapy (mCIMT). The aim of this systematic review is to assess and synthesize the critical aspects of the use of mCIMT in children with OBPP. EVIDENCE ACQUISITION: This systematic review has been carried out according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis). A comprehensive search of the literature was conducted using PubMed, MEDLINE and Evidence Based Medicine Reviews, databases. We enclosed experimental and original articles, case reports and book chapters. Four articles were finally included. EVIDENCE SYNTHESIS: One case report tested the feasibility of mCIMT to encourage use of the affected arm in a child with Erb-Duchenne palsy and documented the clinical changes observed. A case series had the purpose to determine if mCIMT in combination with botulinum toxin (BTX-A) improved arm function in 2 children with OBPP. A cohort study compared the use of mCIMT in 19 OBPP and 18 unilateral Cerebral Palsy. A prospective single-blind RCT described mCIMT versus conventional therapy in a group of 39 children with OBPP. CONCLUSIONS: This systematic review on the use of mCIMT in children with OBPP shows that there is unanimous agreement that a program should last 2 weeks at least. However, there is no scientific evidence supporting a single common mCIMT protocol in the management of OBPP because of a considerable heterogeneity. Further high methodological studies regarding the application of mCIMT for OBPP and based on larger patients' sample should have the potential to optimize the appropriateness of care provided to infants with OBPP and, therefore, their quality of life.

Transfer of the peroneal component of the sciatic nerve in total brachial plexus lesion: An anatomical feasibility study.

Closed brachial plexus lesions (BPLs) are generally associated with a traumatic mechanism of forced traction between the neck and the shoulder-arm complex. For brachial plexus reconstruction different techniques have been proposed with donor motor nerves like intercostal nerves, or the ipsilateral cervical plexus, the phrenic nerve, the contralateral C7 root, and many others. Despite all these surgical possibilities, the overall recovery is generally poor and not satisfactory. The principal drawback is linked to the loss of upper limb proprioception, in a way that dramatically influences even a good motor recovery, so in complete BPLs the sensory loss still represents a debilitating problem. In this anatomical feasibility study, the possibility to transfer the peroneal component of the sciatic nerve as a donor for complete BPLs has been evaluated. This technique would conceptually bring an important motor and sensory contribution to the upper limb using pure motor and sensory branches of the sciatic nerve. Performing immediate tendon transfer for foot drop palsy could significantly decrease the morbidity of the surgical procedure.

The Era of Cortical Bone Trajectory Screws in Spine Surgery: A Qualitative Review with Rating of Evidence.

The use of cortical bone trajectory (CBT) pedicle screws for posterior fixation and fusion seems to constitute a viable alternative for spinal procedures, with the potential to mitigate risks, be minimally invasive, and cause less tissue damage than the traditional technique. This review analyzes the literature regarding CBT according to the rate of evidence of articles and their main focus. CBT has proved to be a safe and viable option for screw fixation in spine surgery. Given the denser bone interception, high-quality biomechanics studies show equal or even better properties compared with classic pedicle screw fixation, depending on several factors such as screw size and length. Through the years, surgical technique has improved to gain a longer and safer trajectory than first described. Level 2 and 3 clinical studies suggest equal clinical and radiologic outcomes compared with pedicle trajectory fixation, but high-quality, level 1, randomized controlled trials are needed to confirm these results.

Cortical bone trajectory technique's outcomes and procedures for posterior lumbar fusion: A retrospective study.

Cortical Bone Trajectory screws allow a limited soft tissue dissection with mechanical properties comparable to traditional pedicle screws. However, clinical results are still reported on limited samples. The study aimed to evaluate perioperative and mid-term follow up outcomes, clinical results and complications in 238 consecutive patients underwent CBT fusion for degenerative lumbosacral disease. Pre- and intraoperative data, clinical outcomes and complications were collected. The patients were stratified in three groups. The original technique was performed in the first 43 cases without a preoperative CT scan planning. The second group includes the patients who underwent preoperative CT scan for entry point and screw trajectory planning (158 patients). Surgical procedures in the last group were performed with patient-matched 3D printed guide (37 patients). The accuracy in screws positioning was evaluated on postoperative CT scan. The mean follow-up was 32.3 months. Mean ODI and VAS index improved with statistical significance. Mean procedural time was 187, 142 and 124 min in the three subgroups. The total amount of recorded complications was 4.2% (16.3%, 3.8% and 0.0% respectively). Screws entirely within the cortex of the pedicle were 78.9%, 90.5% and 93.9% in the three groups. Fusion was obtained in 92.4% of cases. The CBT technique is a safe procedure, especially with an accurate preoperative CT scan-based planning. This seems more evident with the 3D template patient-matched guide. More studies are needed to directly compare traditional pedicle screws and CBT screws on long-term outcomes.

TRANS-FRONTAL SINUS APPROACH FOR OLFACTORY GROOVE MENINGIOMAS: A 19 YEAR EXPERIENCE.

INTRODUCTION: Olfactory groove meningiomas (OGMs) account for 8-13 % of all intracranial meningiomas. The gold standard of treatment is generally surgery, however various approaches have been used and the literature is still uncertain about the superiority of one treatment over the others. The most debated techniques are traditional microscopic open approaches versus the endoscopic endonasal ones. The aim of this paper is to prove a valid surgical route that gathers the benefits of both endoscopic and transcranial routes. METHODS: Fifty consecutive patients underwent trans-frontal sinus surgical removal of an OGM between January 2000 and January 2019 at the Neurosurgical Departments in Torino, Brescia and Legnano (Italy). The clinical features were collected in a database and compared with neuroimaging and outcomes. All patients were investigated with neuroimaging techniques. Clinical evaluations were performed 3-4 months and 1 year after surgery, together with neuroradiological follow-up. RESULTS: All patients with OGM underwent Simpson grade I resection. The most common neurological symptom leading to neuroradiological evaluations were headaches (36 %), followed by behavioural changes (30 %), hyposmia/anosmia (12 %), visual impairments (6%) and focal deficits (6%). At 3-4 months follow-up 48 patients underwent a brain MRI (2 patients underwent a brain CT), and a complete resection was confirmed in 45 patients (94 %). CONCLUSIONS: Despite different techniques and studies supported by good evidence, there is no consensus on the best surgical approach for OGMs. The data shown in this article suggests that the trans-frontal sinus approach is a valid alternative to an endoscopic approach and the classical transcranial routes, collecting benefits from both approaches.

Intraneural Ewing Sarcoma of Fibular Nerve: Case Report, Radiologic Findings and Review of Literature.

BACKGROUND: Intraneural Ewing sarcoma (ES) was first described in 1918 by Stout in a tumor of the ulnar nerve. These tumors are in the category of ES family of tumors, together with ES of bone, extraosseous ES, and primitive neuroectodermal tumor. ES typically occurs in the second decade of life; only 20% of cases affect elder people. The most frequently involved sites are the craniospinal vault and cauda equina, while the peripheral nerve location is extremely rare (only 11 cases mentioned in the literature to date). CASE DESCRIPTION: This case report documents a rare case of a 46-year-old woman with an intraneural extraosseous ES and offers a complete radiologic documentation including contrast magnetic resonance imaging and microbubble contrast-enhanced ultrasonographic data. A review of the literature about diagnostic and treatment management is presented. CONCLUSIONS: The challenge of intraneural extraosseous ES consists of the right balance between the necessity to consider a potential malignant nature of the lesion and perform adequate surgical excision in a relatively brief time from the first clinical examination and the fact that these are extremely rare pathologic entities among most frequent cases of completely benign tumors, which could even have the same clinical and radiologic presentation. For this reason, a multidisciplinary setting with a team of neurosurgeons, orthopedic specialists, radiologists, pathologists, and oncologists should manage these cases as soon as a pathologic diagnosis is available. More attention should be focused on other therapies that effectively manage microscopic pathologic involvement, without increasing the risk of postoperative morbidity.