DOCSLIB.ORG

Journal of Biomechanical Science and Engineering Researches on Biomechanical Properties and Models of Peripheral Nerves

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Journal of Biomechanical Science and Engineering Researches on Biomechanical Properties and Models of Peripheral Nerves Bulletin of the JSME Vol.12, No.1, 2017 Journal of Biomechanical Science and Engineering 【Review Paper】 Researches on biomechanical properties and models of peripheral nerves - a review Ming-Shaung JU*, Chou-Ching K. LIN** and Cheng-Tao CHANG* *Department of Mechanical Engineering, National Cheng Kung University 1 University Road, Tainan 701, Taiwan (R.O.C.) E-mail: [email protected] **Department of Neurology College of Medicine and University Hospital National Cheng Kung University 1 University Road, Tainan 701, Taiwan (R.O.C.) Received: 14 December 2016; Revised: 11 February 2017; Accepted: 6 March 2017 Abstract The biomechanics of peripheral nerve plays an important role in physiology of the healthy and pathology of the diseased such as the diabetic neuropathy, the cauda equine compression and the carpal tunnel syndrome. The other application is recent development of neural prostheses. The goal of this paper is to review researches done by members of Taiwanese Society of Biomechanics on the biomechanics of peripheral nerves in the past two decades. First, a brief introduction of the anatomy of peripheral nerve is given. Then experiment designs and mechanical models for testing the nerves are presented. The material properties ranged from linear elastic to nonlinear visco-elastic and scales ranged from organ level to tissue level are reviewed. Implications of these studies to clinical problems will be addressed and the challenges and future perspective on biomechanics of peripheral nerve are discussed. Key words: Biomechanics, Peripheral nerve, Review, Diabetic mellitus, Cauda equine 1. Introduction Nervous system plays an important role in the human body it can coordinate voluntary and involuntary actions of other tissues and sub-systems. The nervous system can be divided into central nervous system (CNS) and peripheral nervous system (PNS) (Preston and Wilson, 2012). The CNS contains the neurons of the brain and spinal cord and it is the integrative and decision-making part of the nervous system. The PNS refers to parts of the nervous system outside the brain and spinal cord. It is a complicated, extensive network of nerves that collects sensory information and conveys it to the CNS for processing. Nerve tissue is mainly composed of neurons and supporting cells. The neuron can transmit action potential rapidly from one area of the body to the next. It can be divided into four zones as: cell body, dendrite, axon and nerve terminal. Depending on distribution in CNS and PNS the supporting cells have different types. The supporting cells of the PNS are Schwann cells that form myelin to wrap axon of the neuron. In case the peripheral nerve is injured by trauma or neuropathy, the distal zone would be degenerated and the proximal zone may be regenerated to recover the peripheral nerve function. If the affected area is not cared properly it may become a neuroma that causes long-term nerve injury. Drug and physical therapy were commonly utilized to help the injured nerve to recover and regeneration. Diabetic neuropathy, carpal tunnel syndrome, and nerve trauma are common symptoms of nerve injuries in Taiwan and all over the world. The biomechanical properties of peripheral nerves are important factors of the repair and regeneration process of the nerve after injury (Sunderland, 1978). The goal of this paper is to review the researches done by members of Taiwanese Society of Biomechanics on the biomechanics of peripheral nerves in the past two decades. As a background, first, a brief introduction of the anatomy of peripheral nerve is given. Then special experiments designed for in vitro and in situ tests of the nerves are presented. The material properties of peripheral nerves with complexity from linear elastic to nonlinear visco-elastic and scales from organ level to tissue level are also introduced with methods of parameter estimation. Implications of these biomechanics studies to clinical problems will be addressed and the challenges and future perspective on biomechanics of peripheral nerve are discussed. Paper No.16-00678 J-STAGE Advance Publication date: 23 March, 2017 [DOI: 10.1299/jbse.16-00678] © 2017 The Japan Society of Mechanical Engineers 1 Ju, Lin and Chang, Journal of Biomechanical Science and Engineering, Vol.12, No.1 (2017) 2. Anatomy of Peripheral Nerves The axons within the peripheral nerve are long extension of their cell bodies located in the dorsal root ganglia, autonomic ganglia, or the ventral horn of the spinal cord or brain stem (Topp and Boyd, 2006). The axons are insulated from each other, bundled together, and protected by three main connective tissue layers, namely the endoneurium, the perineurium, and the epineurium (Fig. 1). The axon, myelin sheath, and endoneurial components are bundled by a perineurium layer to form a nerve fascicle. Several fascicles are held together by the epineurial connective tissue layer to form a peripheral nerve (Preston and Wilson, 2012). Within the endoneurium, nerve fibers are composed of myelinated and un-myelinated neuron axons. Each fascicle has motor, sensory, and autonomic nerve fibers or just one kind of them. Each myelinated axon is wrapped tightly by a Schwann cell for multiple turns to form a myelin sheath. At node of Ranvier two Schwann cells are separated. Unmyelinated axons are bundled together and enveloped by Schwann cell cytoplasm and plasma membrane. The endoneurium fills the inner space of each fascicle and it is consisted of fibroblasts, type I & II collagen fibrils, few mast cells and macrophages. The collagen fibrils are arranged longitudinally and with a diameter less than 50 nm. It forms an endoneurial tube that contains endoneurial fluid which provides inner pressure of the fascicle. If a fascicle is cut transversely, the inner components of the endoneurium are protruded to a mushroom shape. This pressure can make the fascicle stiffer (Lundborg, 2004; Spencer et al., 1975). The nerve fibers surrounded by the endoneurium have slightly undulating shape such that they can be stretched by a small initial tensile force on the nerve. The endoneurium can resist the outer tensile force but its stiffness is less than that of perineurium and the nerve fibers can be easily compressed and extended by external load (Sunderland, 1978). Fig 1. The ultra-structure and organization of a peripheral nerve. Perineurium is the thinnest but most dense layer of the three connective tissues. It protects the nerve fibers and maintains the inner pressure and stiffness of the fascicle. Fifteen layers of flat perineurial cells are tightly connected to each other within the perineurium. Type I & II collagen fibrils and elastic fibers are filled within the intersection of each layer. Most of these fibers are longitudinally and the rest are cross-over distributed to form dense network. The collagen fibril layers and perineurial cells provided the nerve enough strength against external load. Depending on the size of the fascicle the thickness of the perineurium ranged between of 1.3 to 100 m (Sunderland and Bradley, 1961). The epineurium is an areolar connective tissue to hold nerve fascicles together. For nerves having multiple fascicles, the epineurium is divided into epifascicular epineurium and interfascicular epineurium (Sunderland, 1978; Topp and Boyd, 2006). The epineurium is a loose structure to keep the nerve soft and serves as a buffer barrier to protect the inner fascicles against external load. The epineurium contained type I & III collagen fibrils, elastic fibers, mast cells, and adipose tissue. Most of the collagen fibers were longitudinally distributed and the rest were formed as randomly cross-over arrays. These fibrils were thicker than the other two connective tissues. Similar to many organs, the peripheral nerves are highly vascularized tissues. Transmission of action potential and axonal transport are supported by nutrients supplied by capillary vessels. Intra-neural blood vessels are abundant in all layers of the nerve, forming a pattern of longitudinally oriented vessels (Lundborg, 2004). Based on location the blood vessels can be classified as extrinsic and intrinsic vessels. The extrinsic vessels support vascular plexus superficial and deep layers of the connective tissues. Intrinsic vessels are distributed inside the epineurium, perineurium, and endoneurium. Epineurial arterioles form an anastomotic network running longitudinally within the epifascicular [DOI: 10.1299/jbse.16-00678] © 2017 The Japan Society of Mechanical Engineers 2 Ju, Lin and Chang, Journal of Biomechanical Science and Engineering, Vol.12, No.1 (2017) epineurium and the interfascicular epineurium. Perforating arterioles intersect the perineurium at oblique angles. Peri-neurial arterioles slightly regulated intra-fascicular blood flow with poorly developed smooth muscles. Within the endoneurium the arterioles turn into large-diameter, longitudinally oriented capillaries. After that, venules return blood to the venous system. Generally, the inter-neural blood vessels including arterioles and venules could be defined as vasa nervorum (Moore and Dalley, 2006; Rohkamm, 2014). The peripheral nerves are endured to various mechanical loads under normal physiological conditions imposed by human movements and postures, e.g., the nerve is subjected to tensile stress when joint motion caused elongation of the nerve bed. The carpal tunnel syndrome, a frequently encountered chronic peripheral neuropathy, and neuropathy caused by diabetes mellitus are due to long-term compression of the nerves (Main et al., 2011). When diabetic nerves are subjected to long-term compression, the blood vessels will be damaged followed by injury of the nerve fibers (Dyck et al., 1986; Dyck and Giannini, 1996). 3. Experiment and biomechanical model of peripheral nerves as a whole According to the types of mechanical loads on the peripheral nerves in vivo, two kinds of mechanical tests have been designed, namely, the axial tensile test and transverse compression. The geometry of peripheral nerve is a long string with diameter 1.19 0.10mm for rabbits, rats and 1.2-5mm for human. Therefore, customized testing devices have to be designed to performed in vitro or in vivo tests.
Load more

Recommended publications
  • 685 Mechanisms and Controllers of Eccrine Sweating in Humans Manabu Shiba
    [Frontiers in Bioscience S2, 685-696, January 1, 2010] Mechanisms and controllers of eccrine sweating in humans Manabu Shibasaki1, Craig G. Crandall2,3 1Department of Environmental and Life Sciences, Nara Women's University Graduate School of Humanities and Sciences, Nara Japan, 2Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 3Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital of Dallas, TX TABLE OF CONTENTS 1. Abstract 2. Introduction and historical perspective 3. Neural pathway from the brain to sweat gland 4. Non-thermal modulators of sweat rate 4.1. Effect of exercise in modulating sweat rate 4.2. Effect of baroreceptors in modulating sweat rate 4.3. Effect of body fluid status and osmolality on sweat rate 5. Summary 6. Acknowledgement 7. References 1. ABSTRACT 2. INTRODUCTION AND HISTORICAL PERSPECTIVE Human body temperature is regulated within a very narrow range. When exposed to hyperthermic conditions, via Evaporative heat loss is critical for human survival in environmental factors and/or increased metabolism, heat a hot environment, particularly when environmental dissipation becomes vital for survival. In humans, the temperature is higher than skin temperature. Exercise or primary mechanism of heat dissipation, particularly when exposure to a hot environment elevates internal and skin ambient temperature is higher than skin temperature, is temperatures, and subsequently increases sweat rate and evaporative heat loss secondary to sweat secretion from skin blood flow. Historically it was thought that skin eccrine glands. While the primary controller of sweating is temperature was more important than internal temperature the integration between internal and skin temperatures, a in the control of sweating (24, 109).
    [Show full text]
  • Development of a Functional in Vitro 3D Model of the Peripheral Nerve
    University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2018 Development of a Functional In Vitro 3D Model of the Peripheral Nerve Wesley Anderson University of Central Florida Part of the Disease Modeling Commons Find similar works at: https://stars.library.ucf.edu/etd University of Central Florida Libraries http://library.ucf.edu This Doctoral Dissertation (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Electronic Theses and Dissertations, 2004-2019 by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Anderson, Wesley, "Development of a Functional In Vitro 3D Model of the Peripheral Nerve" (2018). Electronic Theses and Dissertations, 2004-2019. 5946. https://stars.library.ucf.edu/etd/5946 DEVELOPMENT OF A FUNCTIONAL IN VITRO 3D MODEL OF THE PERIPHERAL NERVE by WESLEY ALLEN ANDERSON B.S. UNIVERSITY OF CENTRAL FLORIDA, 2011 M.S. UNIVERSITY OF CENTRAL FLORIDA, 2013 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Burnett School of Biomedical Sciences in the College of Medicine at the University of Central Florida Orlando, Florida Summer Term 2018 Major Professor: Stephen Lambert © 2018 Wesley Anderson ii ABSTRACT Peripheral neuropathies, affect approximately 20 million people in the United States and are often a complication of conditions such as diabetes that can result in amputation of affected areas such as the feet and toes. In vitro methodologies to facilitate the understanding and treatment of these disorders often lack the cellular and functional complexity required to accurately model peripheral neuropathies.
    [Show full text]
  • Fascicular Anatomy of Human Femoral Nerve: Implications for Neural Prostheses Using Nerve Cuff Electrodes
    Volume 46, Number 7, 2009 JRRDJRRD Pages 973–984 Journal of Rehabilitation Research & Development Fascicular anatomy of human femoral nerve: Implications for neural prostheses using nerve cuff electrodes Kenneth J. Gustafson, PhD;1–2* Gilles C. J. Pinault, MD;2–3 Jennifer J. Neville, MD;4 Ishaq Syed, MD;4 John A. Davis Jr, MD;5 Jesse Jean-Claude, MD;2–3 Ronald J. Triolo, PhD1–2,5 1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH; 2Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH; 3Department of Surgery, 4School of Medicine, and 5Department of Orthopedics, Case Western Reserve University, Cleveland, OH Abstract—Clinical interventions to restore standing or stepping ing or walking after paralysis resulting from upper motor by using nerve cuff stimulation require a detailed knowledge of neuron damage secondary to spinal cord injury (SCI), or femoral nerve neuroanatomy. We harvested eight femoral nerves peripheral nerve damage due to trauma, require a detailed with all distal branches and characterized the branching patterns knowledge of the morphology and fascicular anatomy of the and diameters. The fascicular representation of each distal nerve femoral nerve. However, the fascicular anatomy and spe- was identified and traced proximally to create fascicle maps of the cific dimensions of the human femoral nerve have not been compound femoral nerve in four cadaver specimens. Distal nerves fully described and must be quantitatively documented. were consistently represented as individual fascicles or distinct groups of fascicles in the compound femoral nerve. Branch-free The femoral nerve originates from the second, third, length of the compound femoral nerve was 1.50 +/– 0.47 cm and fourth lumbar spinal nerves and innervates the anterior (mean +/– standard deviation).
    [Show full text]
  • A Critical Review of Interfaces with the Peripheral Nervous System for the Control of Neuroprostheses and Hybrid Bionic Systems
    Journal of the Peripheral Nervous System 10:229–258 (2005) REVIEW A critical review of interfaces with the peripheral nervous system for the control of neuroprostheses and hybrid bionic systems Xavier Navarro1, 2 , Thilo B. Krueger3,4,NataliaLago1, Silvestro Micera5, Thomas Stieglitz4,and Paolo Dario5 1Department of Cell Biology, Physiology and Immunology, and Institute of Neurosciences, Universitat Auto` noma de Barcelona (UAB), Bellaterra; 2Institut Guttmann, Badalona, Spain; 3Department of Medical Engineering and Neural Prostheses, Fraunhofer Institute for Biomedical Engineering (IBMT), St. Ingbert; 4Laboratory for Biomedical Microsystems, Institute for Microsystem Technology (IMTEK), University of Freiburg, Freiburg, Germany; and 5ARTS Laboratory, Scuola Superiore Sant’Anna (SSSA), Pisa, Italy Abstract Considerable scientific and technological efforts have been devoted to develop neuroprostheses and hybrid bionic systems that link the human nervous system with electronic or robotic prostheses, with the main aim of restoring motor and sensory functions in disabled patients. A number of neuroprostheses use interfaces with peripheral nerves or muscles for neuromuscular stimulation and signal recording. Herein, we provide a critical overview of the peripheral interfaces available and trace their use from research to clinical application in controlling artificial and robotic prostheses. The first section reviews the different types of non-invasive and invasive electrodes, which include surface and muscular electrodes that can record EMG signals from and stimulate the underlying or implanted muscles. Extraneural electrodes, such as cuff and epineurial electrodes, provide simultaneous interface with many axons in the nerve, whereas intrafascicular, penetrating, and regenerative electrodes may contact small groups of axons within a nerve fascicle. Biological, technological, and material science issues are also reviewed relative to the problems of electrode design and tissue injury.
    [Show full text]
  • Brachial Plexopathies
    British Journal of Medicine & Medical Research 3(4): 928-952, 2013 SCIENCEDOMAIN international www.sciencedomain.org Brachial Plexopathies Josef Finsterer1*, Raffi Topakian2, Julia Wanschitz3, Stefan Quasthoff4, Gerd Bodner5, Wolfgang Grisold6 and Wolfgang N. Löscher3 1Krankenanstalt Rudolfstiftung, Vienna. 2Neurological Department, Wagner-Jauregg Krankenhaus, Linz. 3Neurological Department, Medical University Innsbruck, Innsbruck. 4Neurological Department, Medical University Graz, Graz. 5Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology. Medical University of Vienna, Vienna. 6Neurological Department, Kaiser-Franz-Josef Spital, Vienna, Austria. Authors’ contributions This work was carried out in collaboration between all authors. Author JF designed the study, performed the evaluation of the data, and wrote the first draft of the manuscript. Authors RT, JW, SQ, GB, WG and WNL contributed to the collection and discussion of the data and supported the writing of the manuscript. All authors read and approved the final manuscript Received 1st January 2013 th Review Article Accepted 6 February 2013 Published 11th March 2013 ABSTRACT Lesions of the brachial plexus are most commonly caused by traumatic injuries. Other causes include infiltration by tumors, intrinsic or extrinsic compressions, damage from radiation therapy, or neuralgic amyotrophy (Parsonage-Turner syndrome). Less frequent causes of brachial plexus lesions include metabolic disease (e.g. diabetes), viral infections, immunological reactions to vaccination or infections, drugs, malignancies, paraneoplastic conditions, or hereditary disease (SEPT9 mutations, HNPP). The diagnosis of brachial plexus lesion is based upon history, clinical examination, and instrumental investigations, particularly, nerve conduction studies, electromyography, evoked potentials, magnetic stimulation, and the MRI. Treatment depends on the cause of the plexus lesion and includes prophylactic measures, physiotherapy, drugs, or surgery.
    [Show full text]
  • Interfaces with the Peripheral Nervous System for the Control of a Neuroprosthetic Limb: a Review Kadir A
    Yildiz et al. Journal of NeuroEngineering and Rehabilitation (2020) 17:43 https://doi.org/10.1186/s12984-020-00667-5 REVIEW Open Access Interfaces with the peripheral nervous system for the control of a neuroprosthetic limb: a review Kadir A. Yildiz1, Alexander Y. Shin2 and Kenton R. Kaufman1,3* Abstract The field of prosthetics has been evolving and advancing over the past decade, as patients with missing extremities are expecting to control their prostheses in as normal a way as possible. Scientists have attempted to satisfy this expectation by designing a connection between the nervous system of the patient and the prosthetic limb, creating the field of neuroprosthetics. In this paper, we broadly review the techniques used to bridge the patient’s peripheral nervous system to a prosthetic limb. First, we describe the electrical methods including myoelectric systems, surgical innovations and the role of nerve electrodes. We then describe non-electrical methods used alone or in combination with electrical methods. Design concerns from an engineering point of view are explored, and novel improvements to obtain a more stable interface are described. Finally, a critique of the methods with respect to their long-term impacts is provided. In this review, nerve electrodes are found to be one of the most promising interfaces in the future for intuitive user control. Clinical trials with larger patient populations, and for longer periods of time for certain interfaces, will help to evaluate the clinical application of nerve electrodes. Keywords: amputation, artificial limb, prostheses and implants, neuroprosthesis, peripheral nervous system, neural conduction, electromyography, electric stimulation, electrodes, extremities Background peripheral system.
    [Show full text]
  • Thesis Prodanov
    MORPHOMETRIC ANALYSIS OF THE RAT LOWER LIMB NERVES ANATOMICAL DATA FOR NEURAL PROSTHESIS DESIGN Printing of this thesis was supported by The Biomedical Signals and Systems group, Twente University J.E. Jurriaanse Stichting c D. Prodanov, 2006 No part of this work may be reproduced by print, photocopy, or any other means without a prior written permission from the author. ISBN 90-365-2275-7 NOT FOR SALE This manuscript was typeset by the author with LATEX2ε using type 1 Computer Modern fonts. Refer- ences are formatted with the Natural BiB code using the J. Comp. Neurol. BibTex style shared kindly by P. W. Daly, SI units are formatted using the code of M. Heldoorn. MORPHOMETRIC ANALYSIS OF THE RAT LOWER LIMB NERVES ANATOMICAL DATA FOR NEURAL PROSTHESIS DESIGN PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de rector magnificus, prof. dr. W.H.M. Zijm, volgens besluit van het College voor Promoties in het openbaar te verdedigen op donderdag 26 januari 2006 om 16.45 uur door Dimiter Petkov Prodanov geboren op 16 maart 1975 te Sofia, Bulgarije Dit proefschrift is goedgekeurd door de promotors en assistent promotor prof. dr. E. Marani (promotor) prof. dr. P. Veltink (promotor) dr. H.K.P. Feirabend (assistent promotor) For the less even as for the greater there is some deed that he may accomplish but once only; and in that deed his heart shall rest. J.R.R. Tolkien, The Silmarillion, ch. 9 To my parents andtomyfriendsLuc,Dani,andIvo iii TABLE OF CONTENTS 1 General Introduction 1 1.1Neuralprostheses...................................
    [Show full text]
  • First Report of Peripheral Nerves in Bone from Triceratops Horridus Occipital Condyle
    Downloaded from First Report of Peripheral Nerves in Bone from Triceratops horridus Occipital Condyle https://www.cambridge.org/core Mark H. Armitage DSTRI, Inc. 325 East Washington Street #170, Sequim, WA 98382 [email protected] . IP address: Abstract: Peripheral nerves in vertebrate systems have been studied avian bone (Figure 7). There is disagreement over whether the for centuries. Nerve anatomy, including the connective tissues that epineurium is the site of such crosshatch wrapping [8,13–15] 170.106.40.219 cushion nerves, are well described in the literature. The outer connec- tive tissues, known as the epineurium and perineurium, include a dou- or whether it lies within the perineurium [7,10,11,16,17]. Curi- ble layer of collagen fibers that form a double helical wrapping that is ously, some structural studies of nerve connective tissue fail visible with polarized light microscopy and by other contrast methods. to mention a wrapping pattern at all [9,12,18,19]. Stolinski [15] This wrapping is a diagnostic characteristic of nerve tissues. Decades posits that this weave pattern is restricted to the inner side of , on of research into dinosaur bones have produced interesting endocasts the epineurium. This was visible to him when using reflected 23 Sep 2021 at 11:27:47 of probable brain morphology, but no soft and flexible nerve tissues oblique illumination. However, Glees [7] employed polarized have been reported from dinosaur remains. In this study we provide light examination and illustrated the double helix as part of the evidence of nerve fragments, characterized by a double helical wrap- ping of collagen fibers, from a Triceratops condyle collected at the perineurium (Figure 6).
    [Show full text]
  • Original Article 3D Micro CT Imaging of the Human Peripheral Nerve Fascicle
    Int J Clin Exp Med 2017;10(7):10315-10323 www.ijcem.com /ISSN:1940-5901/IJCEM0048630 Original Article 3D micro CT imaging of the human peripheral nerve fascicle Liwei Yan*, Jian Qi*, Shuang Zhu, Tao Lin, Xiang Zhou, Xiaolin Liu Department of Microsurgery and Orthopaedic Trauma, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, P. R. China. *Equal Contributors. Received July 8, 2016; Accepted April 25, 2017; Epub July 15, 2017; Published July 30, 2017 Abstract: Autologous nerve grafting is the gold standard for the treatment of peripheral nerve injury; however, it in- volves certain complications. With the maturity of three-dimensional (3D) bioprinting techniques, the 3D bioprinting of nerve grafts has become theoretically feasible. The primary 3D bioprinting of nerve grafts results in a 3D nerve structure, in particular, a fascicular 3D structure. The aim of this study was to identify a method for enhancing X- ray micro computed tomography (CT) to reconstruct 3D nerve structures. Here, we used three techniques, Lugol’s iodine solution (I2KI) enhancement, calcium chloride enhancement and freeze-drying (n=6), to identify a better method for obtaining high-resolution 3D images of a normal human peripheral nerve fascicle. Contrast differences were employed to compare the homologous nerve structure with the fascicular structure in each group. Unlike hematoxylin and eosin (H&E) staining and scanning electron microscopy (SEM), the micro CT approach produced continuous serial images, which are necessary for 3D reconstruction. The fascicular increases in the contrast levels were 211.74±31.44%, -6.51±1.46% and 125.41±27.14% for the H&E, SEM and micro CT methods, respectively.
    [Show full text]
  • Structure and Composition of the Outer Connective Tissue Sheaths of Peripheral Nerve
    J. Anat. (1995) 186, pp. 123-130, with 8 figures Printed in Great Britain 123 Structure and composition of the outer connective tissue sheaths of peripheral nerve C. STOLINSKI Department of Anatomy and Cell Biology, St Mary's Hospital Medical School, a Constituent College of Imperial College of Science, Technology and Medicine, London, UK (Accepted 4 August 1994) ABSTRACT A regular pattern of parallel reflections with a periodicity of - 39 gm has been detected on peripheral nerve fascicles. The reflections have been found to originate from a layer of wavy epineurial collagen fibrils arranged in register around the entire circumference of the fascicle. The waves were observed to be disposed in parallel with the plane of the fascicular sheath and along its axis. The pattern was observed in cut or relaxed fascicles in situ as well as in isolated and split layers of the epineurium. The pattern was not observed on nerve fascicles under tension. An additional structural feature consisting of longitudinally disposed elastic fibres was also detected among the epineurial collagen fibrils. The perineurial collagen associated with sheets of cells was found to be disposed in flattened waves as in the inner layer of the epineurium. The period of the waves, however, was much shorter, in the range of 6-9 gm. From the nature of the wavy structure it can be surmised that on stretching or contraction the sheath length may change, thus accommodating displacement and movement of nerve fibres. Key words: Tamarin monkey; rat; human epineurium; perineurium; collagen fibrils; elastic fibres. land, 1965). Thin collagen layers separating the INTRODUCTION perineurial cell laminae were assumed to be arranged The outer epineurial connective tissue layer which in a double spiral system enveloping the entire nerve surrounds peripheral nerve fascicles has been investi- fascicle (Glees, 1943), or to be mainly longitudinal gated rather infrequently (Thomas, 1963; Sunderland, (Thomas, 1963), in all directions (Gamble & Eames, 1965; Ushiki & Ide, 1990).
    [Show full text]
  • Fascicular Perineurium Thickness, Size, and Position Affect
    FASCICULAR PERINEURIUM THICKNESS, SIZE, AND POSITION AFFECT MODEL PREDICTIONS OF NEURAL EXCITATION by YANINA GRINBERG Submitted in partial fulfillment of the requirements For the degree of Masters of Science Thesis Advisor: Dr. Kenneth J. Gustafson Department of Biomedical Engineering CASE WESTERN RESERVE UNIVERSITY May, 2008 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of _____________________________________________________ candidate for the ______________________ degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. Table of Contents I. Introduction ..................................................................................................................... 8 Motivation....................................................................................................................... 8 Peripheral Nerve Anatomy ............................................................................................. 8 Computer Modeling of Neural Anatomy...................................................................... 10 Project Aims and Hypotheses ......................................................................................
    [Show full text]
  • Peripheral Nerve Blockade and the Effects of Paraesthesiae
    00IMRAPT161QOO 10/2/04 7:42 PM Page 3 www.neurorgs.com - Unidad de Neurocirugía RGS Peripheral Nerve Blockade and the Effects of Paraesthesiae MA Reina1, JA De Andrés2, A López1, V Badorrey1 1Department of Anaesthesiology and Critical Care, Hospital de Móstoles, Hospital Madrid Montepríncipe, Madrid & 2Department of Anaesthesiology, Critical Care and Pain Therapy, Consorcio Hospital General Universitario, Valencia, Spain A peripheral nerve consists of bundles of parallel axons, called fas- nucleus. The number of layers depends on the size of the cicles, which are enveloped by a connective tissue sheath. The ensheathed nerve fascicle and is greater around large fascicles of axon distribution within the nerve comprises a plexus in which the nerve fibres. axons are positioned along the path of the fascicles, allowing a close relationship between adjoining axons and their specific The endoneurium location along the nerve [1]. On repeated cuts of a nerve, the The endoneurium is a delicate tubular structure that surrounds topography of the fascicles changes. Generally, the number of the Schwann cells and each capillary within the fascicles [1]. It fascicles increases and the bundle surface area decreases in areas is composed of longitudinally oriented collagen fibres. The where the nerve branches and on the areas next to joints. In con- inner fibres and the ones closest to the Schwann cells have a trast, the number of fascicles decreases and their surface area more disorganised distribution [1]. A basal lamina separates the increases in the areas located between the appearance of the sub- endoneurium from the Schwann and endothelial cells [1]. divisions of the nerve and on the areas between joints.
    [Show full text]