Questions and Answers

2000 ◽  
Vol 5 (2) ◽  
pp. 3-3
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Spinal Nerve ◽  
Sensory Loss ◽  
Residual Symptoms ◽  
Additional Information ◽  
Questions And Answers ◽  
Motor Nerves ◽  
Symptoms And Signs ◽  
Limited Motion

Abstract Lesions of the peripheral nervous system (PNS), whether due to injury or illness, commonly result in residual symptoms and signs and, hence, permanent impairment. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) describes procedures for rating upper extremity neural deficits in Chapter 3, The Musculoskeletal System, section 3.1k; Chapter 4, The Nervous System, section 4.4 provides additional information and an example. The AMA Guides also divides PNS deficits into sensory and motor and includes pain within the former. The impairment estimates take into account typical manifestations such as limited motion, atrophy, and reflex, trophic, and vasomotor deficits. Lesions of the peripheral nervous system may result in diminished sensation (anesthesia or hypesthesia), abnormal sensation (dysesthesia or paresthesia), or increased sensation (hyperesthesia). Lesions of motor nerves can result in weakness or paralysis of the muscles innervated. Spinal nerve deficits are identified by sensory loss or pain in the dermatome or weakness in the myotome supplied. The steps in estimating brachial plexus impairment are similar to those for spinal and peripheral nerves. Evaluators should take care not to rate the same impairment twice, eg, rating weakness resulting from a peripheral nerve injury and the joss of joint motion due to that weakness.

scholarly journals Myelination of the motor nerves in the peripheral nervous system of zebrafish embryos

2016 ◽  
Vol 10 ◽  
Author(s):  
Lee Dong-Won ◽  
Kim Suhyun ◽  
Kim Eunmi ◽  
Jeong Inyoung ◽  
Kim Hwan-Ki ◽  
...  
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Zebrafish Embryos ◽  
Motor Nerves

X-Ray Microprobe Analysis of Frozen Hydrated Cryosections for Study of Central and Peripheral Nervous System

1990 ◽  
Vol 48 (2) ◽  
pp. 356-357
Author(s):  
Albert J. Saubermann ◽  
Carolyn M. Castiglia ◽  
Margaret C. Foster ◽  
Robert S. Lagasse ◽  
Richard M. LoPachin
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Microprobe Analysis ◽  
Dry Mass ◽  
Elemental Distribution ◽  
X Ray ◽  
Additional Information ◽  
Electrophysiological Measurements ◽  
Wet Weight ◽  
Elemental Mass

Knowledge of elemental distribution is of great importance to understanding normal and abnormal function of the nervous system. Because elements of biological interest are easily displaced using conventional preparative methods, low temperature preparative methods are necessary to preserve elemental distribution. We have applied our methods for x-ray microprobe analysis of frozen hydrated cryosections to investigations of the central and peripheral nervous system in invertebrate and vertebrate animals. We have applied these methods to several areas of neuroscience including neuroanatomy/neurochemistry neurophysiology, neuropharmacology, neurotoxicology, and neuropathology.X-ray microprobe analysis is not a substitute for electrophysiological measurements. Unfortunately there is often confusion between what is measured by the electron probe and between what is measured with microelectrodes. The information we obtain from x-ray microprobe analysis (XMPA) provides a measure of elemental mass fraction usually on the basis of dry mass, although using frozen hydrated techniques provides additional information by relating elemental mass to wet weight mass.

scholarly journals Stereology of the Peripheral Nervous System

2019 ◽  
Vol 48 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Danielle L. Brown ◽  
Michael Staup ◽  
Cynthia Swanson
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Qualitative Evaluation ◽  
Nerve Fibers ◽  
Neuron Number ◽  
Human Eye ◽  
Additional Information ◽  
Size Number ◽  
Organ Systems ◽  
Tissue Changes

Qualitative histopathology has been the gold standard for evaluation of morphological tissue changes in all organ systems, including the peripheral nervous system. However, the human eye is not sensitive enough to detect small changes in quantity or size. Peripheral nervous system toxicity can manifest as subtle changes in neuron size, neuron number, axon size, number of myelinated or unmyelinated axons, or number of nerve fibers. Detection of these changes may be beyond the sensitivity of the human eye alone, necessitating quantitative approaches in some cases. Although 2-dimensional (2D) histomorphometry can provide additional information and is more sensitive than qualitative evaluation alone, the results are not always representative of the entire tissue and assumptions about the tissue can lead to bias, or inaccuracies, in the data. Design-based stereology provides 3D estimates of number, volume, surface area, or length, and stereological principles can be applied to peripheral nervous system tissues to obtain accurate and precise estimates, such as neuron number and size, axon number, and total intraepidermal nerve fiber length. This review describes practical stereological approaches to 3 compartments of the peripheral nervous system: ganglia, peripheral nerves, and intraepidermal nerve fibers.

scholarly journals STP Position Paper: Recommended Best Practices for Sampling, Processing, and Analysis of the Peripheral Nervous System (Nerves and Somatic and Autonomic Ganglia) during Nonclinical Toxicity Studies

2018 ◽  
Vol 46 (4) ◽  
pp. 372-402 ◽  
Author(s):  
Brad Bolon ◽  
Georg Krinke ◽  
Mark T. Butt ◽  
Deepa B. Rao ◽  
Ingrid D. Pardo ◽  
...  
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Cross Sections ◽  
Best Practice ◽  
Sympathetic Ganglia ◽  
Spinal Nerve ◽  
Toxicity Screening ◽  
Toxicity Studies ◽  
General Toxicity ◽  
Perfusion Fixation

Peripheral nervous system (PNS) toxicity is surveyed inconsistently in nonclinical general toxicity studies. These Society of Toxicologic Pathology “best practice” recommendations are designed to ensure consistent, efficient, and effective sampling, processing, and evaluation of PNS tissues for four different situations encountered during nonclinical general toxicity (screening) and dedicated neurotoxicity studies. For toxicity studies where neurotoxicity is unknown or not anticipated (situation 1), PNS evaluation may be limited to one sensorimotor spinal nerve. If somatic PNS neurotoxicity is suspected (situation 2), analysis minimally should include three spinal nerves, multiple dorsal root ganglia, and a trigeminal ganglion. If autonomic PNS neuropathy is suspected (situation 3), parasympathetic and sympathetic ganglia should be assessed. For dedicated neurotoxicity studies where a neurotoxic effect is expected (situation 4), PNS sampling follows the strategy for situations 2 and/or 3, as dictated by functional or other compound/target-specific data. For all situations, bilateral sampling with unilateral processing is acceptable. For situations 1–3, PNS is processed conventionally (immersion in buffered formalin, paraffin embedding, and hematoxylin and eosin staining). For situation 4 (and situations 2 and 3 if resources and timing permit), perfusion fixation with methanol-free fixative is recommended. Where PNS neurotoxicity is suspected or likely, at least one (situations 2 and 3) or two (situation 4) nerve cross sections should be postfixed with glutaraldehyde and osmium before hard plastic resin embedding; soft plastic embedding is not a suitable substitute for hard plastic. Special methods may be used if warranted to further characterize PNS findings. Initial PNS analysis should be informed, not masked (“blinded”). Institutions may adapt these recommendations to fit their specific programmatic requirements but may need to explain in project documentation the rationale for their chosen PNS sampling, processing, and evaluation strategy.

Complement activation in the peripheral nervous system following the spinal nerve ligation model of neuropathic pain☆

Pain ◽  
2008 ◽  
Vol 137 (1) ◽  
pp. 182-201 ◽  
Author(s):  
Margaret E. Levin ◽  
Jason G. Jin ◽  
Rui-Ru Ji ◽  
Jeifei Tong ◽  
James D. Pomonis ◽  
...  
Keyword(s):  
Nervous System ◽  
Neuropathic Pain ◽  
Peripheral Nervous System ◽  
Complement Activation ◽  
Spinal Nerve ◽  
Spinal Nerve Ligation

Neuromuscular Disorders

2016 ◽  
pp. 185-212
Author(s):  
Mark B. Bromberg ◽  
Douglas J. Gelb
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Peripheral Nervous System ◽  
Neuromuscular Disorders ◽  
Lesion Site ◽  
Fiber Tracts ◽  
The Central Nervous System ◽  
Motor Nerves ◽  
Structural Lesion ◽  
Single Lesion

Unlike the central nervous system, where a single structural lesion may produce widespread effects because of disruption of ascending and descending fiber tracts, a single structural lesion in the peripheral nervous system produces symptoms in a narrowly localized region, often in a single limb. Many diseases affect the peripheral nervous system diffusely, however, and can’t be localized to a single lesion site. The autonomic, somatic sensory and somatic motor nerves are physically intermingled at some levels of the nervous system and separated at others, but it is useful to conceptualize them as distinct path- ways. Each can be associated with a variety of symptoms.

scholarly journals Assessment of Peripheral Nervous System Alterations in Patients with the Fabry Related GLA-Variant p.A143T

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1027
Author(s):  
Tim Godel ◽  
Katharina von Cossel ◽  
Reinhard E. Friedrich ◽  
Markus Glatzel ◽  
Sima Canaan-Kühl ◽  
...  
Keyword(s):  
Nervous System ◽  
Vascular Permeability ◽  
Peripheral Nervous System ◽  
Spinal Nerve ◽  
Healthy Controls ◽  
Fiber Density ◽  
Magnetic Resonance Neurography ◽  
Intraepidermal Nerve Fiber Density ◽  
Gla Gene ◽  
The Right

The purpose of this study is to examine alterations of the peripheral nervous system (PNS) in oligo-symptomatic patients carrying the Fabry related GLA-gene variant p.A143T by Magnetic Resonance Neurography (MRN) and skin biopsy. This prospective study assessed dorsal root ganglia (DRG) volume L3 to S2, vascular permeability of the DRG L5, S1, and the spinal nerve L5 in five patients carrying p.A143T in comparison to patients with classical Fabry mutations and healthy controls. Moreover, skin punch biopsies above the lateral malleolus of the right foot were obtained in four patients and intraepidermal nerve fiber density (IENFD) was counted individually. Compared to controls, DRG volumes of p.A143T patients were enlarged by 30% (L3, p < 0.05), 35% (L4, p < 0.05), 29% (L5, p = 0.15), 36% (S1, p < 0.01), and 18% (S2, p < 0.05), but less pronounced compared to patients carrying a classical Fabry mutation. Compared to healthy controls, vascular permeability was decreased by 40% (L5 right), 49% (L5 left), 48% (S1 right), and 49% (S1) (p < 0.01–p < 0.001), but non-significant less than patients carrying a classical Fabry mutation. Compared to sex-matched 5% lower normative reference values per decade, IENFD was decreased in three of four patients. MRN and determination of IENFD is able to detect early alteration of the PNS segment in oligo-symptomatic patients with the disease-modifying GLA-variant p.A143T on an individual basis. This procedure might also help in further GLA-variants of uncertain significance for early identification of patients with single major organ manifestation.

Neurorehabilitation approaches for disorders of the peripheral nervous system

2015 ◽  
pp. 224-237
Author(s):  
William Huynh ◽  
Michael Lee ◽  
Matthew Kiernan
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Functional Independence ◽  
Spinal Nerve ◽  
Neurological Deficits ◽  
Nerve Lesion ◽  
Lumbosacral Plexus ◽  
System P ◽  
Different Levels

Disorders of the peripheral nervous system comprise both traumatic and non-traumatic aetiologies that may involve different levels in the spinal cord, emerging spinal nerve roots, brachial or lumbosacral plexus, to the peripheral nerves. Lesions can be focal, as in most cases of traumatic aetiology, or multifocal or generalized as commonly seen in non-traumatic causes. Current rehabilitative strategies aim at reversing the underlying cause of the nerve lesion, whilst at the same time, treating the symptoms, and preventing complications. More specifically, the emphasis of rehabilitation is to maximize functional independence, locomotion, prevent physical deformity, facilitate integration into society, and overall, improve quality of life. This chapter provides a basic understanding of the pathophysiology of neurological deficits associated with lesions of the peripheral nervous system, followed by a systematic discussion of the general principles. The aim is to provide the healthcare professional with a template and practical approach to the delivery of such therapy.

Sensory Loss and Paresthesias

2018 ◽  
pp. 174-206
Author(s):  
Andrea C. Adams
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Genetic Disorders ◽  
Sensory Loss ◽  
Prognostic Information ◽  
The Common ◽  
The Many

Diseases of the peripheral nervous system are common. Patients often present with complaints of numbness and tingling. The many diagnostic possibilities include endocrinopathies, malignancies, infections, and metabolic, toxic, inflammatory, and genetic disorders. Diagnosis is essential to avoid missing a correctable neuropathy and to provide accurate prognostic information. This chapter considers the common polyneuropathies and focal neuropathies that ssunderlie patients’ complaints of sensory loss and paresthesias (ie, spontaneous abnormal sensations).

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