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Scientific Reports Feb 2023The nervous system of the Asteroidea (starfish or seastar) consists of radial nerve cords (RNCs) that interconnect with a ring nerve. Despite its relative simplicity, it...
The nervous system of the Asteroidea (starfish or seastar) consists of radial nerve cords (RNCs) that interconnect with a ring nerve. Despite its relative simplicity, it facilitates the movement of multiple arms and numerous tube feet, as well as regeneration of damaged limbs. Here, we investigated the RNC ultrastructure and its molecular components within the of Pacific crown-of-thorns starfish (COTS; Acanthaster sp.), a well-known coral predator that in high-density outbreaks has major ecological impacts on coral reefs. We describe the presence of an array of unique small bulbous bulbs (40-100 μm diameter) that project from the ectoneural region of the adult RNC. Each comprise large secretory-like cells and prominent cilia. In contrast, juvenile COTS and its congener Acanthaster brevispinus lack these features, both of which are non-corallivorous. Proteomic analysis of the RNC (and isolated neural bulbs) provides the first comprehensive echinoderm protein database for neural tissue, including numerous secreted proteins associated with signalling, transport and defence. The neural bulbs contained several neuropeptides (e.g., bombyxin-type, starfish myorelaxant peptide, secretogranin 7B2-like, Ap15a-like, and ApNp35) and Deleted in Malignant Brain Tumor 1-like proteins. In summary, this study provides a new insight into the novel traits of COTS, a major pest on coral reefs, and a proteomics resource that can be used to develop (bio)control strategies and understand molecular mechanisms of regeneration.
Topics: Animals; Radial Nerve; Proteomics; Starfish; Echinodermata; Nerve Tissue; Cone-Rod Dystrophies
PubMed: 36849815
DOI: 10.1038/s41598-023-30425-1 -
Medicina (Kaunas, Lithuania) Oct 2022:Due to the rarity of radial nerve palsy in humeral shaft fractures in the paediatric population and the lack of data in the literature, the purpose of our study was to...
:Due to the rarity of radial nerve palsy in humeral shaft fractures in the paediatric population and the lack of data in the literature, the purpose of our study was to report the treatment results of six children who sustained a radial nerve injury following a humeral shaft fracture. We treated six paediatric patients with radial nerve palsy caused by a humeral shaft fracture in our department from January 2011 to June 2022. The study group consisted of four boys and one girl aged 8.6 to 17.2 (average 13.6). The mean follow-up was 18.4 months. To present our results, we have used the STROBE protocol designed for retrospective observational studies. We diagnosed two open and four closed humeral shaft fractures. Two simple transverse AO 12A3c; one simple oblique AO 12A2c; two simple spiral AO 12A1b/AO 12A1c and one intact wedge AO 12B2c were recognized. The humeral shaft was affected in the distal third five times and in the middle third one time. In our study group, we found two cases of neurotmesis; two entrapped nerves within the fracture; one stretched nerve over the bone fragments and one case of neuropraxia. We found restitution of the motor function in all cases. For all patients, extensor muscle strength was assessed on the grade M4 according to the BMRC scale (except for a patient with neuropraxia-M5). The differences in patients concerned the incomplete extension at the radiocarpal and metacarpophalangeal (MCP) joints. In our small case series, humeral shaft fractures complicated with radial nerve palsy are always challenging medical issues. In paediatric patients, we highly recommend an US examination where it is possible to be carried out to improve the system of decision making. Expectant observation with no nerve exploration is reasonable only in close fractures caused by low-energy trauma. Early surgical nerve exploration related with fracture stabilisation is highly recommended in fractures after high-energy trauma, especially in open fractures and where symptoms of nerve palsy appear at any stage of conservative treatment.
Topics: Male; Female; Humans; Child; Radial Neuropathy; Retrospective Studies; Humeral Fractures; Radial Nerve; Humerus; Fracture Fixation, Internal
PubMed: 36363527
DOI: 10.3390/medicina58111571 -
Brain and Behavior Jan 2014This study focuses on an anatomic variation in which the lateral antebrachial cutaneous nerve (LACN) innervates the radial border of the dorsum of the hand and thumb in...
INTRODUCTION
This study focuses on an anatomic variation in which the lateral antebrachial cutaneous nerve (LACN) innervates the radial border of the dorsum of the hand and thumb in addition to, or replacing, the superficial radial nerve (RSN). Here, we propose a technique of nerve conduction that identifies this variation.
METHODS
We studied nerve conduction in 200 upper limbs of two series of 50 volunteers. We sought evidence of the aforementioned variation on the dorsum of the hand and in the thumb.
RESULTS
We found eight occurrences of this variation on the dorsum of the hand and 11 variants on the thumb within the two respective series of 100 upper limbs studied.
DISCUSSION
The RSN-LACN anatomic variation can be studied using nerve conduction. The knowledge of this variation is particularly important for the evaluation of proximal radial nerve injury.
Topics: Adult; Anatomic Variation; Female; Forearm; Hand; Humans; Male; Musculocutaneous Nerve; Neural Conduction; Radial Nerve; Thumb
PubMed: 24653956
DOI: 10.1002/brb3.195 -
Journal of Neurophysiology Feb 2022Unmyelinated tactile (C-tactile or CT) afferents are abundant in arm hairy skin and have been suggested to signal features of social affective touch. Here, we recorded...
Unmyelinated tactile (C-tactile or CT) afferents are abundant in arm hairy skin and have been suggested to signal features of social affective touch. Here, we recorded from unmyelinated low-threshold mechanosensitive afferents in the peroneal and radial nerves. The most distal receptive fields were located on the proximal phalanx of the third finger for the superficial branch of the radial nerve and near the lateral malleolus for the peroneal nerve. We found that the physiological properties with regard to conduction velocity and mechanical threshold, as well as their tuning to brush velocity, were similar in CT units across the antebrachial ( = 27), radial ( = 8), and peroneal ( = 4) nerves. Moreover, we found that although CT afferents are readily found during microneurography of the arm nerves, they appear to be much more sparse in the lower leg compared with C-nociceptors. We continued to explore CT afferents with regard to their chemical sensitivity and found that they could not be activated by topical application to their receptive field of either the cooling agent menthol or the pruritogen histamine. In light of previous studies showing the combined effects that temperature and mechanical stimuli have on these neurons, these findings add to the growing body of research suggesting that CT afferents constitute a unique class of sensory afferents with highly specialized mechanisms for transducing gentle touch. Unmyelinated tactile (CT) afferents are abundant in arm hairy skin and are thought to signal features of social affective touch. We show that CTs are also present but are relatively sparse in the lower leg compared with C-nociceptors. CTs display similar physiological properties across the arm and leg nerves. Furthermore, CT afferents do not respond to the cooling agent menthol or the pruritogen histamine, and their mechanical response properties are not altered by these chemicals.
Topics: Adult; Affect; Afferent Pathways; Antipruritics; Female; Histamine; Histamine Agonists; Humans; Leg; Male; Mechanoreceptors; Menthol; Nerve Fibers, Unmyelinated; Nociceptors; Peroneal Nerve; Radial Nerve; Touch Perception; Young Adult
PubMed: 35020516
DOI: 10.1152/jn.00310.2021 -
Journal of Orthopaedics and... Mar 2019Little evidence regarding the extent of recovery of radial nerve lesions with associated humerus trauma exists. The aim of this study is to examine the incidence and...
BACKGROUND
Little evidence regarding the extent of recovery of radial nerve lesions with associated humerus trauma exists. The aim of this study is to examine the incidence and resolution of types of radial nerve palsy (RNP) in operative and nonoperative humeral shaft fracture populations.
MATERIALS AND METHODS
Radial nerve lesions were identified as complete (RNPc), which included motor and sensory loss, and incomplete (RNPi), which included sensory-only lesions. Charts were reviewed for treatment type, radial nerve status, RNP resolution time, and follow-up time. Descriptive statistics were used to document incidence of RNP and time to resolution. Independent-samples t-test was used to determine significant differences between RNP resolution time in operative and nonoperative cohorts.
RESULTS
A total of 175 patients (77 operative, 98 nonoperative) with diaphyseal humeral shaft injury between 2007 and 2016 were identified and treated. Seventeen out of 77 (22.1%) patients treated operatively were diagnosed preoperatively with a radial nerve lesion. Two (2.6%) patients developed secondary RNPc postoperatively. Eight out of 98 (8.2%) patients presented with RNP postinjury for nonoperatively treated humeral shaft fracture. All patients who presented with either RNPc, RNPi, or iatrogenic RNP had complete resolution of their RNP. No statistically significant difference was found in recovery time when comparing the operative versus nonoperative RNPc, operative versus nonoperative RNPi, or RNPc versus RNPi patient groups.
CONCLUSIONS
All 27 (100%) patients presenting with or developing radial nerve palsy in our study recovered. No patient required further surgery for radial nerve palsy. Radial nerve exploration in conjunction with open reduction and internal fixation (ORIF) appears to facilitate speedier resolution of RNP when directly compared with observation in nonoperative cases, although not statistically significantly so. These findings provide surgeons valuable information they can share with patients who sustain radial nerve injury with associated humerus shaft fracture or nonunion.
LEVEL OF EVIDENCE
Level III treatment study.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Fracture Fixation, Internal; Humans; Humeral Fractures; Male; Middle Aged; Postoperative Complications; Radial Nerve; Radial Neuropathy; Reoperation; Young Adult
PubMed: 30923949
DOI: 10.1186/s10195-019-0526-2 -
Skeletal Radiology Sep 2023To evaluate the effect of maximal pronation and supination of the forearm on the alignment and anatomic relationship of the deep branch of the radial nerve (DBRN) at the...
OBJECTIVE
To evaluate the effect of maximal pronation and supination of the forearm on the alignment and anatomic relationship of the deep branch of the radial nerve (DBRN) at the superior arcade of the supinator muscle (SASM) by using high-resolution ultrasound (HRUS).
MATERIALS AND METHODS
In this cross-sectional study, HRUS in the long axis of the DBRN was performed in asymptomatic participants enrolled from March to August 2021. DBRN alignment was evaluated by measuring angles of the nerve in maximal pronation and maximal supination of the forearm independently by two musculoskeletal radiologists. Forearm range of motion and biometric measurements were recorded. Student t, Shapiro-Wilk, Pearson correlation, reliability analyses, and Kruskal-Wallis test were used.
RESULTS
The study population included 110 nerves from 55 asymptomatic participants (median age, 37.0 years; age range, 16-63 years; 29 [52.7%] women). There was a statistically significant difference between the DBRN angle in maximal supination and maximal pronation (Reader 1: 95% CI: 5.74, 8.21, p < 0.001, and Reader 2: 95% CI: 5.82, 8.37, p < 0.001). The mean difference between the angles in maximal supination and maximal pronation was approximately 7° for both readers. ICC was very good for intraobserver agreement (Reader1: r ≥ 0.92, p < 0.001; Reader 2: r ≥ 0.93, p < 0.001), as well as for interobserver agreement (phase 1: r ≥ 0.87, p < 0.001; phase 2: r ≥ 0.90, p < 0.001).
CONCLUSION
The extremes of the rotational movement of the forearm affect the longitudinal morphology and anatomic relationships of the DBRN, primarily demonstrating the convergence of the nerve towards the SASM in maximal pronation and divergence in maximal supination.
Topics: Humans; Female; Adult; Adolescent; Young Adult; Middle Aged; Male; Radial Nerve; Pronation; Supination; Cross-Sectional Studies; Reproducibility of Results; Cadaver; Forearm
PubMed: 37010538
DOI: 10.1007/s00256-023-04332-5 -
Journal of Orthopaedic Surgery (Hong... 2018The prevalence of radial nerve injury during surgery is as high as the prevalence of radial nerve injury due to trauma. The aim of this study is to minimize the risk of...
INTRODUCTION
The prevalence of radial nerve injury during surgery is as high as the prevalence of radial nerve injury due to trauma. The aim of this study is to minimize the risk of iatrogenic injury of radial nerve.
MATERIALS AND METHODS
Fifty patients with middle or distal diaphysis fractures of humerus and 18 patients with pseudoarthrosis at the same localizations were treated with surgery. Plate-screw fixation was performed with anterior approach in 43 patients. Eleven patients had minimally invasive plate osteosynthesis, and 14 patients had intramedullary nailing. The localization of the radial nerve was determined with nerve stimulator at the area of dissection.
RESULTS
Iatrogenic radial nerve injury did not occur in patients treated with open reduction or minimally invasive approach.
DISCUSSION
Nerve stimulator may be a method that decreases radial nerve injury, an iatrogenic complication. This method may be used in anterior approach and minimally invasive procedures.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bone Plates; Bone Screws; Equipment Design; Female; Fracture Fixation, Internal; Humans; Humeral Fractures; Intraoperative Period; Male; Middle Aged; Minimally Invasive Surgical Procedures; Postoperative Complications; Radial Nerve; Radial Neuropathy; Transcutaneous Electric Nerve Stimulation; Young Adult
PubMed: 30278806
DOI: 10.1177/2309499018803002 -
CMAJ : Canadian Medical Association... Sep 2011Peripheral nerve palsies of the upper extremities presenting at birth can be distressing for families and care providers. It is therefore important to be able to... (Review)
Review
BACKGROUND
Peripheral nerve palsies of the upper extremities presenting at birth can be distressing for families and care providers. It is therefore important to be able to identify patients whose diagnosis is compatible with full recovery so that their families can be reassured.
METHODS
We conducted a retrospective review of all infants presenting with weakness of the upper extremity to our clinic between July 1995 and September 2009. We also conducted a review of the current literature.
RESULTS
During the study period, 953 infants presented to our clinic. Of these patients, 25 were identified as having isolated radial nerve palsy (i.e., a radial nerve palsy in isolation with good shoulder function and intact flexion of the elbow). Seventeen infants (68.0%) had a subcutaneous nodule representing fat necrosis in the inferior posterolateral portion of the affected arm. Full recovery occurred in all patients within a range of one week to six months, and 72.0% of the patients (18/25) had fully recovered by the time they were two months old.
INTERPRETATION
Although the outcome of obstetrical brachial plexus palsy is highly variable, isolated radial nerve palsy in the newborn carries a uniformly favourable prognosis.
Topics: Female; Humans; Infant, Newborn; Male; Prognosis; Radial Neuropathy; Retrospective Studies
PubMed: 21768251
DOI: 10.1503/cmaj.110272 -
Journal of Clinical Medicine Mar 2024: This study investigates the surgical state-of-the-art procedure for humeral shaft fractures with primary radial nerve palsy based on its own case series in relation to...
: This study investigates the surgical state-of-the-art procedure for humeral shaft fractures with primary radial nerve palsy based on its own case series in relation to the current and established literature. : Retrospective review of treated cases between January 2018 and December 2022 describing radial nerve palsy after humerus shaft fractures, radiological fracture classification, intraoperative findings, surgical procedure, patient follow-up and functional outcome. : A total of 804 patients (463 women and 341 men) with humerus shaft fractures were identified. A total of 33 patients showed symptomatic lesions of the radial nerve (4.1%). The primary lesion was identified in 17 patients (2.1%). A broad and inhomogeneous distribution of fractures according to the AO classification was found. According to the operative reports, the distraction of the radial nerve was found eleven times, bony interposed three times and soft tissue constricted/compressed three times. In every case the radial nerve was surgically explored, there was no case of complete traumatic nerve transection. Four intramedullary nails and thirteen locking plates were used for osteosynthesis. Complete recovery of nerve function was seen in 12 cases within 1 to 36 months. Three patients still showed mild hypesthesia in the thumb area after 18 months. Two patients were lost during follow-up. : With this study, we support the strategy of early nerve exploration and plate osteosynthesis in humeral fractures with primary radial nerve palsy when there is a clear indication for surgical fracture stabilisation. In addition, early exploration appears sensible in the case of palsies in open fractures and secondary palsy following surgery without nerve exposure as well as in the case of diagnostically recognisable nerve damage. Late nerve exploration is recommended if there are no definite signs of recovery after 6 months. An initial wait-and-see strategy with clinical observation seems reasonable for primary radial nerve palsies without indication for surgical fracture stabilisation.
PubMed: 38610658
DOI: 10.3390/jcm13071893 -
PloS One 2021Fixation of humeral shaft fractures with a plate and screws can endanger the neurovascular structure if proper care is not taken. No studies to our knowledge have...
INTRODUCTION
Fixation of humeral shaft fractures with a plate and screws can endanger the neurovascular structure if proper care is not taken. No studies to our knowledge have studied the risk of iatrogenic radial nerve and/or profunda brachii artery (RNPBA) injury from each screw hole of a 4.5 mm narrow dynamic compression plate (narrow DCP). The purpose of this study is to evaluate the risk of RNPBA injury in anterolateral humeral plating with a 4.5 mm narrow DCP.
MATERIAL AND METHODS
18 humeri of 9 fresh-frozen cadavers in the supine position were exposed via the anterolateral approach with 45 degrees of arm abduction. A hypothetical fracture line was marked at the midpoint of each humerus. A precontoured ten-hole 4.5mm narrow DCP was applied to the anterolateral surface of the humerus using the fracture line to position the center of the plate. All screw holes were drilled and screws inserted. The cadaver was then turned over to the prone position with 45 degrees of arm abduction, and the RNPBA exposed. The holes through in which 100% of the screw had contact with or penetrated the RNPBA were identified as dangerous screw holes, while lesser percentages of contact were defined as risky.
RESULTS
The relative distance ratios of the entire humeral length from the lateral epicondyle of the humerus to the 4th, 3rd, 2nd and 1st proximal holes were 0.64, 0.60, 0.56 and 0.52, respectively. The most dangerous screw hole was the 2nd proximal, in which all 18 screws had contacted or penetrated the nerve, followed by the risky 1st (12/18), 3rd (8/18) and 4th (2/18) holes.
CONCLUSION
In humeral shaft plating with the 4.5mm narrow DCP using the anterolateral approach, the 2nd proximal screw hole carries the highest risk of iatrogenic radial nerve and/or profunda brachii artery injury.
Topics: Aged; Bone Plates; Brachial Artery; Cadaver; Female; Fracture Fixation, Internal; Humans; Humeral Fractures; Humerus; Male; Middle Aged; Patient Positioning; Radial Nerve; Risk Factors
PubMed: 34847166
DOI: 10.1371/journal.pone.0260448