Effects of Pacap on Schwann Cells: Focus on Nerve Injury.

Schwann cells, the most abundant glial cells of the peripheral nervous system, represent the key players able to supply extracellular microenvironment for axonal regrowth and restoration of myelin sheaths on regenerating axons. Following nerve injury, Schwann cells respond adaptively to damage by acquiring a new phenotype. In particular, some of them localize in the distal stump to form the Bungner band, a regeneration track in the distal site of the injured nerve, whereas others produce cytokines involved in recruitment of macrophages infiltrating into the nerve damaged area for axonal and myelin debris clearance. Several neurotrophic factors, including pituitary adenylyl cyclase-activating peptide (PACAP), promote survival and axonal elongation of injured neurons. The present review summarizes the evidence existing in the literature demonstrating the autocrine and/or paracrine action exerted by PACAP to promote remyelination and ameliorate the peripheral nerve inflammatory response following nerve injury.

Dextran-based tube-guides for the regeneration of the rat sciatic nerve after neurotmesis injury.

In this work, dextran-based nerve tube-guides were prepared, characterized and used in a standardized animal model of neurotmesis injury. Non-porous and porous transparent tube-guides were obtained by photocrosslinking of two co-macromonomers based on dextran and poly(ε-caprolactone) (PCL). Swelling capacity of the tube-guides ranged from 40-60% with no visible constriction of their inner diameter. In vitro hydrolytic degradation tests showed that the tube-guides maintained their structural integrity up to 6 months. The in vivo performance of the tube-guides was evaluated by entubulation of the rat sciatic nerve after a neurotmesis injury, with a 10 mm-gap between the nerve stumps. The results showed that the tube-guides were able to promote the regeneration of the nerve in a similar manner to what was observed with conventional techniques (nerve graft and end-to-end suture). Stereological analysis proved that nerve regeneration occurred, and both tube-guides presented fibre diameter and g-ratio closer to healthy sciatic nerves. The histomorphometric analysis of Tibialis anterior (TA) skeletal muscle showed decreased neurogenic atrophy in the porous tube-guides treated group, presenting measurements that are similar to the uninjured control.

Pressure Injuries Treated With Anodal and Cathodal High-voltage Electrical Stimulation: the Effect on Blood Serum Concentration of Cytokines and Growth Factors in Patients With Neurological Injuries. A Randomized Clinical Study.

It remains unclear whether electrical currents can affect biological factors that determine chronic wound healing in humans. PURPOSE: The aim of this study was to determine whether anodal and cathodal high-voltage monophasic pulsed currents (HVMPC) provided to the area of a pressure injury (PI) change the blood level of cytokines (interleukin [IL]-1ß, IL-10, and tumor necrosis factor [TNF]-α) and growth factors (insulin-like growth factor [IGF]-1 and transforming growth factor [TGF]-ß1) in patients with neurological injuries and whether the level of circulatory cytokines and growth factors correlates with PI healing progression. METHODS: This study was part of a randomized clinical trial on the effects of HVMPC on PI healing. All patients with neurological injuries (spinal cord injury, ischemic stroke, and blunt trauma to the head) and a stage 2, stage 3, or stage 4 PI of at least 4 weeks' duration hospitalized in one rehabilitation center were eligible to participate if older than 18 years of age and willing to consent to donating blood samples. Exclusion criteria included local contraindications to electrical stimulation (cancer, electronic implants, osteomyelitis, tunneling, necrotic wounds), PIs requiring surgical intervention, patients with poorly controlled diabetes mellitus (HbA1C > 7%), critical wound infection, and/or allergies to standard wound treatment. Participants were randomly assigned to 1 of 3 groups: anodal (AG) or cathodal (CG) HVMPC treatment (154 µs; 100 Hz; 360 µC/sec; 1.08 C/day) or a placebo (PG, sham) applied for 50 minutes a day, 5 days per week, for 8 weeks. TNF-α, IL-1ß, IL-10, TGF-ß1, and IGF-1 levels in blood serum were assessed using the immunoenzyme method (ELISA) and by chemiluminescence, respectively, at baseline and week 4. Wound surface area measurements were obtained at baseline and week 4 and analyzed using a digitizer connected to a personal computer. Statistical analyses were performed using the maximum-likelihood chi-squared test, the analysis of variance Kruskal-Wallis test, the Kruskal-Wallis post-hoc test, and Spearman's rank order correlation; the level of significance was set at P ≤.05. RESULTS: Among the 43 participants, 15 were randomized to AG (mean age 53.87 ± 13.30 years), 13 to CG (mean age 51.08 ± 20.43 years), and 15 to PG treatment (mean age 51.20 ± 14.47 years). Most PIs were located in the sacral region (12, 74.42%) and were stage 3 (11, 67.44%). Wound surface area baseline size ranged from 1.00 cm2 to 58.04 cm2. At baseline, none of the variables were significantly different. After 4 weeks, the concentration of IL-10 decreased in all groups (AG: 9.8%, CG: 38.54%, PG: 27.42%), but the decrease was smaller in the AG than CG group (P = .0046). The ratio of pro-inflammatory IL-10 to anti-inflammatory TNF-α increased 27.29% in the AG and decreased 26.79% in the CG and 18.56% in the PG groups. Differences between AG and CG and AG and PG were significant (AG compared to CG, P = .0009; AG compared to PG, P = .0054). Other percentage changes in cytokine and growth factor concentration were not statistically significant between groups. In the AG, the decrease of TNF-α and IL-1ß concentrations correlated positively with the decrease of PI size (P <.05). CONCLUSION: Anodal HVMPC elevates IL-10/TNF-α in blood serum. The decrease of TNF-α and IL-1ß concentrations in blood serum correlates with a decrease of PI wound area. More research is needed to determine whether the changes induced by anodal HVMPC improve PI healing and to determine whether and how different electrical currents affect the activity of biological agents responsible for specific wound healing phases, both within wounds and in patients' blood. In clinical practice, anodal HVMPC should be used to increase the ratio of anti-inflammatory IL-10 to pro-inflammatory TNF-α , which may promote healing.

Nitrous Oxide Impairs Axon Regeneration after Nervous System Injury in Male Rats.

BACKGROUND: Nitrous oxide can induce neurotoxicity. The authors hypothesized that exposure to nitrous oxide impairs axonal regeneration and functional recovery after central nervous system injury. METHODS: The consequences of single and serial in vivo nitrous oxide exposures on axon regeneration in four experimental male rat models of nervous system injury were measured: in vitro axon regeneration in cell culture after in vivo nitrous oxide administration, in vivo axon regeneration after sharp spinal cord injury, in vivo axon regeneration after sharp optic nerve injury, and in vivo functional recovery after blunt contusion spinal cord injury. RESULTS: In vitro axon regeneration 48 h after a single in vivo 70% N2O exposure is less than half that in the absence of nitrous oxide (mean ± SD, 478 ± 275 um; n = 48) versus 210 ± 152 um (n = 48; P < 0.0001). A single exposure to 80% N2O inhibits the beneficial effects of folic acid on in vivo axonal regeneration after sharp spinal cord injury (13.4 ± 7.1% regenerating neurons [n = 12] vs. 0.6 ± 0.7% regenerating neurons [n = 4], P = 0.004). Serial 80% N2O administration reverses the benefit of folic acid on in vivo retinal ganglion cell axon regeneration after sharp optic nerve injury (1277 ± 180 regenerating retinal ganglion cells [n = 7] vs. 895 ± 164 regenerating retinal ganglion cells [n = 7], P = 0.005). Serial 80% N2O exposures reverses the benefit of folic acid on in vivo functional recovery after blunt spinal cord contusion (estimate for fixed effects ± standard error of the estimate: folic acid 5.60 ± 0.54 [n = 9] vs. folic acid + 80% N2O 5.19 ± 0.62 [n = 7], P < 0.0001). CONCLUSIONS: These data indicate that nitrous oxide can impair the ability of central nervous system neurons to regenerate axons after sharp and blunt trauma.

The Effect of SPTLC2 on Promoting Neuronal Apoptosis is Alleviated by MiR-124-3p Through TLR4 Signalling Pathway.

To investigate the role and mechanism of microRNA-124-3p (miR-124-3p) and serine palmitoyltransferase long chain base subunit 2 (SPTLC2) in neuronal apoptosis induced by mechanical injury. Transient transfection was used to modify the expression of miR-124-3p and SPTLC2. After transfection, neuronal apoptosis was evaluated in an in vitro injury model of primary neurons using TUNEL staining and western blot. The correlation between miR-124-3p and SPTLC2 was identified through a dual luciferase reporter assay in HEK293 cells. A rescue experiment in primary neurons was performed to further confirm the result. To explore the downstream mechanisms, co-immunoprecipitation was performed to identify proteins that interact with SPTLC2 in toll-like receptor 4 (TLR4) signalling pathway. Subsequently, the relative expression levels of TLR4 pathway molecules were measured by western blot. Our results showed that increased miR-124-3p can inhibit neuronal apoptosis, which is opposite to the effect of SPTLC2. In addition, miR-124-3p was proved to negatively regulate SPTLC2 expression and suppress the apoptosis-promoting effect of SPTLC2 via the TLR4 signalling pathway.

When an octopus has MS: Application of neurophysiology and immunology of octopuses for multiple sclerosis.

Multiple sclerosis (MS) is an immune-mediated disease which can cause different symptoms due to the involvement of different regions of the central nervous system (CNS). Although this disease is characterized by the demyelination process, the most important feature of the disease is its degenerative nature. This nature is clinically manifested as progressive symptoms, especially in patients' walking, which can even lead to complete debilitation. Therefore, finding a treatment to prevent the degenerative processes is one of the most important goals in MS studies. To better understand the process and the effect of drugs, scientists use animal models which mostly consisting of mouse, rat, and monkey. In evolutionary terms, octopuses belong to the invertebrates which have many substantial differences with vertebrates. One of these differences is related to the nervous system of these organisms, which is divided into central and peripheral parts. The difference lies in the fact that the main volume of this system expands in the limbs of these organisms instead of their brain. This offers a kind of freedom of action and processing strength in the octopus limbs. Also, the brain of these organisms follows a non-somatotopic model. Although the complex actions of this organism are stimulated by the brain, in contrast to the human brain, this activity is not related to a specific region of the brain; rather the entire brain area of the octopus is activated during a process. Indeed, the brain mapping or the topological perception of a particular action, such as moving the limbs, reflects itself in how that activity is distributed in the octopus brain neurons. Accordingly, various actions are known with varying degrees of activity of neurons in the brain of octopus. Another important feature of octopuses is their ability to regenerate defective tissues including the central and peripheral nervous system. These characteristics raise the question of what features can an octopus show when it is used as an organism to create experimental autoimmune encephalomyelitis (EAE). Can the immune system damage of the octopus brain cause a regeneration process? Will the autonomy of the organs reduce the severity of the symptoms? This article seeks to provide evidence to prove that use of octopuses as laboratory samples for generation of EAE may open up new approaches for researchers to better approach MS.

Autophagy in Neurotrauma: Good, Bad, or Dysregulated.

Autophagy is a physiological process that helps maintain a balance between the manufacture of cellular components and breakdown of damaged organelles and other toxic cellular constituents. Changes in autophagic markers are readily detectable in the spinal cord and brain following neurotrauma, including traumatic spinal cord and brain injury (SCI/TBI). However, the role of autophagy in neurotrauma remains less clear. Whether autophagy is good or bad is under debate, with strong support for both a beneficial and detrimental role for autophagy in experimental models of neurotrauma. Emerging data suggest that autophagic flux, a measure of autophagic degradation activity, is impaired in injured central nervous systems (CNS), and interventions that stimulate autophagic flux may provide neuroprotection in SCI/TBI models. Recent data demonstrating that neurotrauma can cause lysosomal membrane damage resulting in pathological autophagosome accumulation in the spinal cord and brain further supports the idea that the impairment of the autophagy-lysosome pathway may be a part of secondary injury processes of SCI/TBI. Here, we review experimental work on the complex and varied responses of autophagy in terms of both the beneficial and detrimental effects in SCI and TBI models. We also discuss the existing and developing therapeutic options aimed at reducing the disruption of autophagy to protect the CNS after injuries.

Dexterous Hand Movements and Their Recovery After Central Nervous System Injury.

Hand dexterity has uniquely developed in higher primates and is thought to rely on the direct corticomotoneuronal (CM) pathway. Recent studies have shown that rodents and carnivores lack the direct CM pathway but can control certain levels of dexterous hand movements through various indirect CM pathways. Some homologous pathways also exist in higher primates, and among them, propriospinal (PrS) neurons in the mid-cervical segments (C3-C4) are significantly involved in hand dexterity. When the direct CM pathway was lesioned caudal to the PrS and transmission of cortical commands to hand motoneurons via the PrS neurons remained intact, dexterous hand movements could be significantly recovered. This recovery model was intensively studied, and it was found that, in addition to the compensation by the PrS neurons, a large-scale reorganization in the bilateral cortical motor-related areas and mesolimbic structures contributed to recovery. Future therapeutic strategies should target these multihierarchical areas.

Neurite Development and Repair in Worms and Flies.

How the nervous system is wired has been a central question of neuroscience since the inception of the field, and many of the foundational discoveries and conceptual advances have been made through the study of invertebrate experimental organisms, including Caenorhabditis elegans and Drosophila melanogaster. Although many guidance molecules and receptors have been identified, recent experiments have shed light on the many modes of action for these pathways. Here, we summarize the recent progress in determining how the physical and temporal constraints of the surrounding environment provide instructive regulations in nervous system wiring. We use Netrin and its receptors as an example to analyze the complexity of how they guide neurite outgrowth. In neurite repair, conserved injury detection and response-signaling pathways regulate gene expression and cytoskeletal dynamics. We also describe recent developments in the research on molecular mechanisms of neurite regeneration in worms and flies.

Optogenetic Modulation and Reprogramming of Bacteriorhodopsin-Transfected Human Fibroblasts on Self-Assembled Fullerene C60 Nanosheets.

Fullerenes have unique biocompatibility and photoelectric properties and are candidate materials for biomedical applications. Several cell membrane proteins in nature such as bacteriorhodopsin also have photoelectric properties. Highly expressible bacteriorhodopsin (HEBR) is a novel light-sensitive opsin that has the potential to trigger neural activities through optogenetic modulation. Here, HEBR plasmids are delivered to human fibroblasts and the cells are exposed to C60 fullerene self-assembled 2D nanosheets. Results show that the above approach combined with light stimulation (3 s duration and three times per day) may promote reprogramming and differentiation of human fibroblasts into neural-like cells in 7 d without any neural induction medium. The special photoelectric properties of fullerenes as culture substrates and transfected HEBR on the cell membrane may provide a new optogenetic platform for regulating the location (C60 nanosheet) and time (frequency of light illumination) for human fibroblasts to become neural-like cells, and may be applied to improve neural regeneration in the future.

New Insights of a Neuronal Peptidase DINE/ECEL1: Nerve Development, Nerve Regeneration and Neurogenic Pathogenesis.

Our understanding of the physiological relevance of unique Damage-induced neuronal endopeptidase (DINE) [also termed Endothelin-converting enzyme-like 1 (ECEL1)] has recently expanded. DINE/ECEL1 is a type II membrane-bound metalloprotease, belonging to a family including the neprilysin (NEP) and endothelin-converting enzyme (ECE). The family members degrade and/or process peptides such as amyloid ß and big-endothelins, which are closely associated with pathological conditions. Similar to NEP and ECE, DINE has been expected to play an important role in injured neurons as well as in developing neurons, because of its remarkable transcriptional response to neuronal insults and predominant neuronal expression from the embryonic stage. However, the physiological significance of DINE has long remained elusive. In the last decade, a series of genetically manipulated mice have driven research progress to elucidate the physiological aspects of DINE. The mice ablating Dine fail to arborize the embryonic motor axons in some subsets of muscles, including the respiratory muscles, and die immediately after birth. The abnormal phenotype of motor axons is also caused by one amino acid exchanges of DINE/ECEL1, which are responsible for distal arthrogryposis type 5 in a group of human congenital movement disorders. Furthermore, the mature Dine-deficient mice in which the lethality is rescued by genetic manipulation have shown the involvement of DINE in central nervous system regeneration. Here we describe recent research advances that DINE-mediated proteolytic processes are critical for nerve development, regeneration and pathogenesis, and discuss the future potential for DINE as a therapeutic target for axonal degeneration/disorder.

Creative Minds in the Aftermath of the Great War: Four Neurologically Wounded Artists.

Many artists were involved in the First World War. Some of them were mobilized, like millions of soldiers, others enlisted to fight on the battlefield. The stories of writers who returned neurologically wounded from the war, such as Guillaume Apollinaire (1880-1918) or Blaise Cendrars (1887-1961), are well-known. The cases of painters and sculptors who suffered from First World War neurological wounds are scarce. Nevertheless, their injuries led to intense modifications of artistic practice. We detail four examples of artists whose creative mind was impacted by their First World War neurological wounds or diseases. The painter Jean-Julien Lemordant (1878-1968), who suffered from blindness after his injury, stopped his artistic work and became an icon of Franco-American friendship. The sculptor Maurice Prost (1894-1967), suffering from a neuroma due to the loss of his arm, built a special device to continue his work as a wildlife artist. The painter Georges Braque (1882-1963) was trepanned but carried on with his cubist work without ever mentioning the conflict. Conversely, the painter Fernand Léger (1881-1955), who suffered from a war neurosis, produced a significant war testimony through drawings and letters.

The Changes of MicroRNA Expression in the Corpus Cavernosum of a Rat Model With Cavernous Nerve Injury.

BACKGROUND: MicroRNAs (miRs) were found to be dysregulated in erectile dysfunction (ED) related to aging, type 2 diabetes mellitus, and vasculogenic abnormalities. However, miR expression in ED after radical prostatectomy (RP) is not known. AIM: To detect abnormal miR expression in post-RP ED and analyze target genes and pathways. METHODS: 16 Sprague Dawley rats were divided into bilateral cavernous nerve crush (BCNC) and control groups. 4 weeks after surgery, erectile function and histological change in the corpus cavernosum were evaluated. Total RNA from 3 rats from each group was isolated and processed to analyze the miR expression profiling by RNA sequencing. The top 10 up-regulated miR profiles were chosen directly and further validated in another 5 rats per each group by quantitative real-time polymerase chain (PCR) reaction. The target genes were predicted by online databases, including: TargetScan, mirwalk, miRanda, miRDB, and DIANA. The enrichment analysis of gene ontology-term analysis and Kyoto Encyclopedia of Genes and Genomes were performed by DAVID database. OUTCOMES: Intra-cavernosal pressure, mean arterial pressure, smooth muscle content, and miR expression were measured. RESULTS: Compared to the control group, the BCNC group had decreased intra-cavernosal/mean arterial pressure ratio and smooth muscle marker (α-smooth muscle actin). The sequence results showed that 124 miR expression dysregulated in the BCNC group, in which 122 miR expression were up-regulated. Of the 122 miRs, 21 miR expressions were increased above 2-fold. Among the top 10 up-regulated miRs, 4 miRs (miR-101a, miR-138, miR-338, and miR-142) levels were finally validated for over-expression by quantitative (PCR) reaction. The gene ontology analysis results showed that these 4 miRs could regulate the processes of cell apoptosis, fibrosis, endothelium, and smooth muscle cells function. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed the target genes were involved in 7 pathways related to ED. CLINICAL TRANSLATION: Our findings provide novel insights into post-RP ED that may stimulate further studies to develop miR targeted therapy or damage detection for ED. STRENGTHS & LIMITATIONS: To our knowledge, this is the first study to identify the miR profiling and function in the BCNC rat model. The rat model might not represent the human condition and the miR was only detected at 1 period. Besides that, there is a high probability of false positives for RNA sequence results. CONCLUSION: 4 dysregulated miRs were found in the BCNC rat model, which may be related to post-RP ED by regulating apoptosis, fibrosis, endothelial, and smooth muscle cells. Liu C, Cao Y, Ko TC, et al. The Changes of MicroRNA Expression in the Corpus Cavernosum of a Rat Model With Cavernous Nerve Injury. J Sex Med 2018;15:958-965.

'Surface Transplantation' for Nerve Injury and Repair: The Quest for Minimally Invasive Cell Delivery.

Cell transplantation is an ambitious, but arguably realistic, therapy for repair of the nervous system. Cell delivery is a major challenge for clinical translation, especially given the apparently inhibitory astrogliotic environment in degenerated tissue. However, astrogliotic tissue also contains endogenous structural and biochemical cues that can be harnessed for functional repair. Minimizing damage to these cues during cell delivery could enhance cell integration. This theory is supported by studies with an auditory astrocyte scar model, in which cells delivered onto the surface of the damaged nerve were more successfully integrated in the host than those injected into the tissue. We consider the application of this less invasive approach for nerve injury and its potential application to some neurodegenerative disorders.

Long-Term Outcomes of Glenohumeral Arthrodesis.

BACKGROUND: Glenohumeral arthrodesis is associated with a high rate of complications. Although patients experience reasonable pain relief and shoulder stability, they experience marked limitations in their upper-extremity function. The purpose of this study was to examine the clinical outcomes of glenohumeral arthrodesis. METHODS: Twenty-nine patients with 29 affected shoulders underwent primary glenohumeral arthrodesis between 1992 and 2009. Surgical indications included rotator cuff arthropathy and pseudoparalysis (n = 7), neurologic injuries (n = 12), chronic infection (n = 3), recurrent dislocations (n = 3), and proximal humeral or shoulder girdle tumors (n = 4). Surgical fixation techniques included plates and screws in 18 patients and screws only in 11 patients. RESULTS: All patients were examined, with a mean follow-up of 12 years (range, 2 to 22 years). Twelve patients (41%) had postoperative complications, including 6 periprosthetic fractures, 7 nonunions, and 3 infections. Eleven patients (38%) required additional surgical procedures after arthrodesis, including revision internal fixation to achieve glenohumeral fusion after nonunions (n = 7), irrigation and debridement with antibiotic treatment for deep infections (n = 2), open reduction and internal fixation to treat fracture (n = 2), and implant removal to treat symptomatic patients (n = 3). Patients experienced reasonable overall pain relief. The mean postoperative scores were 35 points for the Subjective Shoulder Value, 58 points for the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and 54 points for the Short Form-36. Eighty-seven percent of patients reported postoperative limitations. Patients with neurologic injuries had worse functional outcomes, and an arthrodesis position of ≥25° yielded better functional outcomes. CONCLUSIONS: Glenohumeral arthrodesis is associated with a high rate of patients with complications (41%). Although patients experience reasonable pain relief and shoulder stability, they experience marked limitations in their upper-extremity function. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Long-Term Regular Eccentric Exercise Decreases Neuropathic Pain-like Behavior and Improves Motor Functional Recovery in an Axonotmesis Mouse Model: the Role of Insulin-like Growth Factor-1.

Although training programs with regular eccentric (ECC) exercise are more commonly used for improving muscular strength and mobility, ECC exercise effects upon functional recovery of the sciatic nerve has not yet been determined. After sciatic nerve crush, different mice groups were subjected to run on the treadmill for 30 min at a speed of 6, 10, or 14 m/min with - 16° slope, 5 days per week, over 8 weeks. During the training time, neuropathic pain-like behavior (mechanical and cold hyperalgesia) was assessed and functional recovery was determined with the grip strength test and the Sciatic Functional and Static indexes (SFI and SSI). After 9 weeks, triceps surae muscle weight and morphological alterations were assessed. Tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß), interleukin-4 (IL-4), interleukin-1Ra (IL-1Ra), insulin-like growth factor-1 (IGF-1) levels, and markers pro- and anti-inflammatory and regeneration, respectively, were quantified in the muscle and sciatic nerve on day 14 post-crushing. Exercised groups presented less neuropathic pain-like behavior and better functional recovery than non-exercised groups. Biochemically, ECC exercise reduced TNF-α increase in the muscle. ECC exercise increased sciatic nerve IGF-1 levels in sciatic nerve crush-subjected animals. These findings provide new evidence indicating that treatment with ECC might be a potential approach for neuropathy induced by peripheral nerve injury.

Ubiquitin C-terminal hydrolase-L1 (UCH-L1) as a therapeutic and diagnostic target in neurodegeneration, neurotrauma and neuro-injuries.

INTRODUCTION: Since its discovery as a major CNS-abundant protein 25 years ago, Ubiquitin C-terminal hydrolase-L1 (UCH-L1) has emerged as an important enzyme in regulating brain protein metabolism, by coupling to the proteasome pathway of protein degradation. Areas covered: UCH-L1 is implicated in both familial and sporadic Parkinson disease and other chronic neurodegenerative diseases. Also, UCH-L1 has been recently emerging as a biofluid-based biomarker for various forms of acute neurotrauma and CNS injury. Expert opinion: The loss of UCH-L1 activity coupled with the gain of proteinopathy function are linked to neurodegeneration such as Parkinsonism and Alzheimer's disease. In addition, certain post-translational modifications of UCH-L1 might promote the conversion of the cytosolic UCH-L1(C) to the membrane-associated UCH-L1(M) form, which seems to play a role in alpha-synucleinopathy formation. Thus, targeting the conversion of UCH-L1(C) to the UCH-L1(M) form might be the key to developing therapies for neurodegenerative diseases linked to UCH-L1. In parallel, UCH-L1 is also emerging as a promising neuron-derived biomarker for traumatic brain injury, ischemic and homographic stroke, pediatric hypoxic-ischemic encephalopathy, spinal cord injury, epileptic seizure and cardiac arrest. This shows that UCH-L1 has strong potential as a robust and universal biomarker target for various forms of CNS injury.

A New Combined Technique Reducing the Risk of Paraplegia during Thoracoabdominal Aorta Replacement.

Acute spinal cord ischemia during thoracoabdominal aorta replacement is a dreadful complication. Existing tools (motor evoked potential [MEP] and somatosensory evoked potential [SSEP]) do not allow differentiating between central and peripheral paraplegia. Therefore, the surgeon often performs unnecessary reimplantation of intercostal arteries: this is time consuming, and significantly increases bleeding complications. We present a simple technique combining MEP and peripheral compound muscle action potential induced by posterior tibialis nerve stimulation, enabling the surgeon to quickly discriminate between central and peripheral neurologic injury. The surgeon has one more tool to drive in real time the optimal surgical strategy. This strategy guides the decision as to which side branches ought to be reimplanted, thus minimizing the risk of paraplegia.

Powered Exoskeletons for Walking Assistance in Persons with Central Nervous System Injuries: A Narrative Review.

Individuals with central nervous system injuries are a large and apparently rapidly expanding population-as suggested by 2013 statistics from the American Heart Association. Increasing survival rates and lifespans emphasize the need to improve the quality of life for this population. In persons with central nervous system injuries, mobility limitations are among the most important factors contributing to reduced life satisfaction. Decreased mobility and subsequently reduced overall activity levels also contribute to lower levels of physical health. Braces to assist walking are options for greater-functioning individuals but still limit overall mobility as the result of increased energy expenditure and difficulty of use. For individuals with greater levels of mobility impairment, wheelchairs remain the preferred mobility aid yet still fall considerably short compared with upright bipedal walking. Furthermore, the promise of functional electrical stimulation as a means to achieve walking has yet to materialize. None of these options allow individuals to achieve walking at speeds or levels comparable with those seen in individuals with unimpaired gait. Medical exoskeletons hold much promise to fulfill this unmet need and have advanced as a viable option in both therapeutic and personal mobility state, particularly during the past decade. The present review highlights the major developments in this technology, with a focus on exoskeletons for lower limb that may encompass the spine and that aim to allow independent upright walking for those who otherwise do not have this option. Specifically reviewed are powered exoskeletons that are either commercially available or have the potential to restore upright walking function. This paper includes a basic description of how each exoskeleton device works, a summation of key features, their known limitations, and a discussion of current and future clinical applicability.

Neonatal Factors Associated with a Good Neurodevelopmental Outcome in Very Preterm Infants.

Objective This study aims to examine the association between the absence of neonatal comorbidities, as well as the presence of indicators of clinical progress with good neurodevelopmental (ND) outcomes, at 18 months corrected age in a national cohort of preterm infants of < 29 weeks' gestation. Design Study subjects included preterm infants (< 29 weeks' gestation) born in 2010 and 2011. Univariate analyses were conducted and regression estimates were calculated for variables where odds of a good ND outcome, composite scores ≥ 100 in three domains (cognitive, language, and motor) in the Bayley Scales of Infant and Toddler Development, 3rd ed. (Bayley-III), were estimated. Results In total, 2,069 infants were included in the analyses. For all three domains evaluated on the Bayley-III, cognition, language, motor, respectively, the absence of three major morbidities was associated with a score ≥ 100: bronchopulmonary dysplasia, necrotizing enterocolitis, and severe neurological injury. Less time spent on positive pressure support and on total parenteral nutrition administration were associated with a positive motor outcome and showed a positive trend for both cognition and language scores. Conclusion The absence of neonatal comorbidities was associated with good ND outcome. Less time spent on positive pressure support and parenteral nutrition may also contribute to a good ND outcome.