scholarly journals Neurotoxic Agents and Peripheral Neuropathy

2021 ◽  
Author(s):  
Neslihan Eskut ◽  
Asli Koskderelioglu
Keyword(s):  
Heavy Metals ◽  
Nervous System ◽  
Peripheral Neuropathy ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Treatment Options ◽  
Nerve Fibers ◽  
Pattern Of Injury ◽  
Extrapyramidal Signs ◽  
Neurobehavioral Symptoms

Neurotoxicity may develop with exposure to various substances such as antibiotics, chemotherapeutics, heavy metals, and solvents. Some plants and fungi are also known to be neurotoxic. Neurotoxicity can develop acutely within hours, or it can develop as a result of exposure for years. Neurotoxicity can be presented with central or peripheral nervous system findings such as neurobehavioral symptoms, extrapyramidal signs, peripheral neuropathy. Peripheral nerve fibers are affected in different ways by neurotoxicant injury. The pattern of injury depends on the target structure involved. The focus of this chapter includes signs, symptoms, pathophysiology, and treatment options of neurotoxicity.

scholarly journals Clinical aspects of B vitamin use

2021 ◽  
Vol 5 (9) ◽  
pp. 579-585
Author(s):  
E.V. Biryukova ◽  
◽  
M.V. Shinkin ◽  
Keyword(s):  
Nervous System ◽  
Diabetic Neuropathy ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Nerve Fibers ◽  
B Vitamins ◽  
Clinical Aspects ◽  
Vegetative Nervous System ◽  
High Blood Glucose ◽  
B Vitamin

Polyneuropathy is a common disorder of the peripheral nervous system. Diabetic neuropathy is the most common and most studied variant of polyneuropathies. The duration of carbohydrate metabolism disorders and inadequate glycemic control are risk factors for nervous system damage in diabetes. Distal neuropathy is a common type of neuropathy associated with diabetes. Interconnecting pathological mechanisms initiated by high blood glucose result in the damage of peripheral nerve fibers. Clinical presentations of distal neuropathy depend on the damage of proximal or distal and sensory or motor nerve fibers and the involvement of the vegetative nervous system. Medications improving metabolic processes in nerve fibers and reducing the severity of peripheral nerve damage are beneficial in addressing the harmful effects of hyperglycemia. Neurometabolic therapy includes thiamine, pyridoxine, and cyanocobalamin (B vitamins) which provide neurotropic effects. B vitamins acting as co-factors in many enzymatic reactions significantly affect the normal functioning of nerve fibers. B vitamins are effective and safe agents used to treat peripheral nervous system diseases for many years. This paper discusses the potential use of B vitamins for diabetic neuropathy and the COVID-19 treatment and rehabilitation. KEYWORDS: polyneuropathy, hyperglycemia, diabetes, distal neuropathy, B vitamins, thiamine, pyridoxine, cyanocobalamin, COVID-19. FOR CITATION: Biryukova E.V., Shinkin M.V. Clinical aspects of B vitamin use. Russian Medical Inquiry. 2021;5(9):579–585 (in Russ.). DOI: 10.32364/2587-6821-2021-5-9-579-585.

scholarly journals Dependence on Schwann Cell-Derived Laminin-γ1 Differentiates Early Lymphoid and Myeloid Development

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 37-37
Author(s):  
Kristin Komnick ◽  
Jennifer May ◽  
Pouneh Kermani ◽  
Sreemanti Basu ◽  
Irene Hernandez ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Nervous System ◽  
Schwann Cell ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Schwann Cells ◽  
Adrenergic Nerve ◽  
Spleen Size ◽  
Mouse Line ◽  
Myeloid Development

Blood cell production is regulated by peripheral nerve fibers that innervate the bone marrow. However, little is known about the development or maintenance of hematopoietic innervation. Schwann cells (SCs) are the primary axon 'support cells' of the peripheral nervous system (PNS), and abnormal SC development is sufficient to impair peripheral nerve function. SCs are also the primary repair cell for the PNS which makes them an attractive therapeutic target for normalization of drug or malignancy-induced 'hematopoietic neuropathy'. We hypothesized that neural regulation of hematopoiesis is dependent on SC development. To test this hypothesis, we used the Myelin Protein Zero-Cre (MP0-Cre); Lamc1fl/fl mouse line in which laminin-γ1 expression is deleted from SC precursors and their progeny1. Early SC maturation is dependent on autocrine SC precursor-derived molecules such as laminin-γ1. SC differentiation arrests prior to axon sorting and ensheathment in MP0-Cre; Lamc1fl/fl mice, and causes a global peripheral neuropathy that persists throughout the lifetime of the animal. Preliminary hematopoietic analysis of 'steady state' MP0-Cre; Lamc1fl/fl and littermate control mice has shown the following: (1) MP0-Cre; Lamc1fl/fl bone marrow is innervated, and Cre-mediated gene recombination occurs in cells immunophenotypically consistent with SCs throughout the peripheral nervous system, including those in the bone marrow; (2) MP0-Cre; Lamc1fl/fl mice are lymphopenic but not neutropenic; (3) MP0-Cre; Lamc1fl/fl mice have significantly reduced spleen size and cellularity; and (4) MP0-Cre; Lamc1fl/fl bone marrow has an ~50% reduction in Lin-Sca-1+Kit+(LSK) cells (measured as a percentage of the Lin- compartment of the bone marrow). These results are consistent with earlier work by our groups in which we found that global Lamc1 gene deletion in adult mice induced peripheral blood lymphopenia, reduced spleen size, and a niche-dependent reduction of lymphoid progenitor and precursor cells that was secondary to increased lymphoid precursor cell apoptosis and reduced proliferation (UBC-CreERT2; Lamc1fl/fl mouse line). As with the SC-specific laminin-γ1 deficient mice, myelopoiesis was preserved in the UBC-CreERT2; Lamc1fl/fl mice. Based on results from MP0-Cre; Lamc1fl/fl and UBC-CreERT2; Lamc1fl/fl mice, we conclude that early lymphoid but not myeloid development requires laminin-γ1 expression by MP0-Cre-targetted niche cells, i.e. Schwann Cells. Our results are consistent with reports from other labs that hematopoietic sympathetic neuropathy promotes aberrant myeloid expansion at the expense of lymphopoiesis2. Going forward, we will determine whether lymphopoietic development is dependent on global versus laminin-specific SC-derived cues, and whether these signals are transmitted directly between SCs and lymphoid biased HSPCs or indirectly via other components of the hematopoietic niche. We anticipate that this line of investigation will provide molecular insights and pharmacologic targets for prevention and or normalization of the 'hematopoietic neuropathy' induced by diabetes, aging, neurotoxic chemotherapies and myeloid malignancies. REFERENCES: 1 Yu, W. M., Feltri, M. L., Wrabetz, L., Strickland, S. & Chen, Z. L. Schwann cell-specific ablation of laminin gamma1 causes apoptosis and prevents proliferation. J Neurosci25, 4463-4472, doi:10.1523/JNEUROSCI.5032-04.2005 (2005). 2 Maryanovich, M. et al. Adrenergic nerve degeneration in bone marrow drives aging of the hematopoietic stem cell niche. Nat Med24, 782-791, doi:10.1038/s41591-018-0030-x (2018). Disclosures No relevant conflicts of interest to declare.

A Case of Fever and a Wrist Drop

2018 ◽  
pp. 69-74
Author(s):  
Aaron E. Miller ◽  
Tracy M. DeAngelis ◽  
Michelle Fabian ◽  
Ilana Katz Sand
Keyword(s):  
Nervous System ◽  
Gastrointestinal Tract ◽  
Peripheral Neuropathy ◽  
Peripheral Nerve ◽  
Polyarteritis Nodosa ◽  
Joint Pain ◽  
Immunosuppressive Agents ◽  
Nerve Biopsy ◽  
Definitive Diagnosis ◽  
Wrist Drop

Polyarteritis nodosa (PAN) is a systemic illness that most often involves the skin, kidneys, and gastrointestinal tract, in addition to the peripheral nervous system. It most often affects middle-aged individuals, men more than women. The particular type of peripheral neuropathy is often mononeuropathy or mononeuritis multiplex—a condition in which there is discrete involvement of multiple individual nerves. Definitive diagnosis of the vascular nature of the neuropathy requires peripheral nerve biopsy, which will demonstrate inflammation throughout the walls of small and medium-sized arteries. The CNS is also frequently involved in PAN. Constitutional symptoms, including fever, fatigue, and diffuse muscle and joint pain, are common and raise the suspicion of a systemic illness. Treatment generally involves the use of corticosteroids and immunosuppressive agents such as cyclophosphamide or azathioprine.

Peripheral Nerve

2016 ◽  
pp. 119-134
Author(s):  
Robert J. Spinner
Keyword(s):  
Nervous System ◽  
Neuropathic Pain ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Systematic Approach ◽  
Major Focus ◽  
Inflammatory Conditions ◽  
The Common ◽  
Oral Examinations

Peripheral nerve is an important and historical part of neurosurgery. It also has been a major focus of both the written and oral examinations administered by the American Board of Neurological Surgeons (ABNS). The Oral Board candidate must be prepared for potentially one to several questions on some of the common disorders of the peripheral nervous system. In this chapter, a systematic approach to peripheral nerve problems is presented. Common areas that might be examined include tumors, injuries, inflammatory conditions, entrapments, and neuropathic pain. Five cases are illustrated, and “pearls” are provided. At the conclusion of the chapter are nine photographs representing problems the Oral Board candidate should be able to identify and answer.

scholarly journals Propylthiouracil and peripheral neuropathy

1992 ◽  
Vol 50 (2) ◽  
pp. 239-240
Author(s):  
Valentina Van Boekel ◽  
José Maurício Godoy ◽  
Luiz A. Lamy ◽  
Samira Assuf ◽  
João G. Corrêa Meyer Neto ◽  
...  
Keyword(s):  
Nervous System ◽  
Peripheral Neuropathy ◽  
Toxic Effect ◽  
Peripheral Nervous System ◽  
Graves Disease ◽  
Neurological Manifestations ◽  
Neurological Signs ◽  
Rare Manifestation

Peripheral neuropathy is a rare manifestation in hyperthyroidism. We describe the neurological manifestations of a 38 year old female with Graves' disease who developed peripheral neuropathy in the course of her treatment with propylthiouracil. After the drug was tapered off, the neurological signs disappeared. Therefore, we call attention for a possible toxic effect on peripheral nervous system caused by this drug.

scholarly journals ДИНАМИКА ИЗМЕНЕНИЙ СТРУКТУР ПАРАНЕВРИЯ В ПОСТНАТАЛЬНОМ ОНТОГЕНЕЗЕ

Innova ◽  
2020 ◽  
pp. 26-28
Author(s):  
Бородина К.А. ◽  
Затолокина М.А. ◽  
Харченко В.В. ◽  
Затолокина М.А. ◽  
Мишина Е.С. ◽  
...  
Keyword(s):  
Nervous System ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Peripheral Nerves ◽  
Full Range ◽  
Structural Features ◽  
Morphological Features ◽  
Depth Data ◽  
Age Related

Currently, there is a lot of literature and research that reflects data on the structure of the peripheral nervous system. However, it should be noted that the results available in the sources do not contain a full range of data on the structural features of paraneural structures and have some contradictions. In addition, data on the morphological features of the structure of the paranephrium of peripheral nerves in ontogenesis are practically absent. This was the beginning of our research, in order to obtain new, more in-depth data on the age-related variability of the peripheral nerve paraneurium.

scholarly journals Long-term Follow-up and Histological Correlation of Peripheral Nervous System Alterations in Neurofibromatosis Type 2

2021 ◽  
Author(s):  
Tim Godel ◽  
Philipp Bäumer ◽  
Said Farschtschi ◽  
Klaus Püschel ◽  
Barbara Hofstadler ◽  
...  
Keyword(s):  
Nervous System ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Nerve Lesions ◽  
Peripheral Nerve Lesions

Abstract Purpose To examine long-term alterations of the dorsal root ganglia (DRG) and the peripheral nerve in patients with neurofibromatosis type 2 (NF2) by in vivo high-resolution magnetic resonance neurography (MRN) and their correlation to histology. Methods In this prospective study the lumbosacral DRG, the right sciatic, tibial, and peroneal nerves were examined in 6 patients diagnosed with NF2 and associated polyneuropathy (PNP) by a standardized MRN protocol at 3 T. Volumes of DRG L3–S2 as well as peripheral nerve lesions were assessed and compared to follow-up examinations after 14–100 months. In one patient, imaging findings were further correlated to histology. Results Follow-up MRN examination showed a non-significant increase of volume for the DRG L3: +0.41% (p = 0.10), L4: +22.41% (p = 0.23), L5: +3.38% (p = 0.09), S1: +10.63% (p = 0.05) and S2: +1.17% (p = 0.57). Likewise, peripheral nerve lesions were not significantly increased regarding size (2.18 mm2 vs. 2.15 mm2, p = 0.89) and number (9.00 vs. 9.33, p = 0.36). Histological analyses identified schwannomas as the major correlate of both DRG hyperplasia and peripheral nerve lesions. For peripheral nerve microlesions additionally clusters of onion-bulb formations were identified. Conclusion Peripheral nervous system alterations seem to be constant or show only a minor increase in adult NF2. Thus, symptoms of PNP may not primarily attributed to the initial schwannoma growth but to secondary long-term processes, with symptoms only occurring if a certain threshold is exceeded. Histology identified grouped areas of Schwann cell proliferations as the correlate of DRG hyperplasia, while for peripheral nerve lesions different patterns could be found.

Peripheral Nerves: Not Only Cross-sectional Area in the Era of Radiomics

2020 ◽  
Vol 24 (02) ◽  
pp. 175-180
Author(s):  
Alberto Stefano Tagliafico ◽  
Raquel Prada González ◽  
Federica Rossi ◽  
Bianca Bignotti ◽  
Carlo Martinoli
Keyword(s):  
Nervous System ◽  
Peripheral Nerve ◽  
Peripheral Nervous System ◽  
Internal Control ◽  
Peripheral Nerves ◽  
Imaging Techniques ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Musculoskeletal Radiology ◽  
Cross Sectional

AbstractThe peripheral nervous system is increasingly being investigated using medical imaging as a complement or in association with electrodiagnostics tests. The application of imaging techniques, such as ultrasound (US) and magnetic resonance imaging (MRI), allows detailed visualization of the peripheral nervous system. According to the European Society of Musculoskeletal Radiology, the use of US for nerve evaluation is strongly encouraged. In addition, the role of US is further enhanced by the wide application of US-guided techniques to diagnose or to treat peripheral nerve disorders.Standard evaluation of peripheral nerves on US usually relies on cross-sectional area evaluation with different cutoff values in the osteofibrous tunnels and outside them. In several anatomical areas, side-to-side comparison is highly recommended because it helps distinguish subtle variations by using the unaffected limb as an internal control.US is widely used to perform US-guided interventional procedures on peripheral nerves. The recent development of radiomics and machine and deep learning applied to peripheral nerves may reveal new insights beyond the capabilities of the human eye. Radiomics may have a role in expanding the diagnostic capabilities of US and MRI in the study of peripheral nerve pathology, especially when the cross-sectional area is not markedly increased.

Rating Peripheral Neuropathy

2003 ◽  
Vol 8 (1) ◽  
pp. 1-10
Author(s):  
Christopher R. Brigham
Keyword(s):  
Nervous System ◽  
Peripheral Neuropathy ◽  
Medical Condition ◽  
Nerve Fibers ◽  
Sensory Loss ◽  
Toxic Exposure ◽  
Fourth Edition ◽  
Afferent Nerve Fibers ◽  
Discrimination Testing ◽  
Underlying Medical Condition

Abstract This article discusses the evaluation of peripheral nerve impairment and focuses on assessing peripheral polyneuropathies. Although peripheral neuropathy is a common neurological disorder, no uniform criteria exist for either evaluation or diagnosis, and 30% of cases remain idiopathic. The patient must be at maximum medical improvement (MMI) before permanent impairment is rated, but determining MMI is challenging, particularly if neuropathy is secondary to an underlying medical condition such as hypothyroid or diabetic neuropathy or toxic exposure. A table in this article directs readers to specific tables from the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) for determining maximum motor and sensory loss. Sensory dysfunction is evaluated by whether it interferes with performance of daily functions, and another table compares sensory gradings according to the AMA Guides, Fifth Edition (Tables 16-10 and 13-23) and the Fourth Edition (Table 11). When using these tables, evaluators should be aware of differences in terminology: sensation is the acceptance and activation of impulses in the afferent nerve fibers of the nervous system, and sensibility is the conscious appreciation and interpretation of the stimulus. In addition, a box discusses two-point discrimination testing and steps the examiner can take to minimize the variability of this procedure. Grading a sensory deficit requires considerable judgment and interpretation, which makes the findings less objective than findings that are independently verifiable.

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