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Sample records for acrylamide-induced axonal neuropathy

  1. Neuroprotective Effect of Calpeptin on Acrylamide-Induced Neuropathy in Rats.

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    Wei, Xiaomin; Yan, Fengfeng; E, Meng; Zhang, Cuili; Li, Guozhen; Yang, Xiwei; Zhang, Fengmei; Wang, Shue; Yu, Sufang

    2015-11-01

    Acrylamide (ACR) is a vinyl monomer with established human neurotoxic effects, which is characterized by the accumulation of neurofilaments (NFs) in the distal swellings of large axons in peripheral and central nervous systems. However, the mechanisms of neurotoxicity remain unclear. The objective is to investigate the neuroprotective effect of calpeptin (CP) on ACR-induced neuropathy and its mechanism. Female adult Wistar rats were randomly divided into four groups (control, CP, ACR, and ACR + CP group). Control group received 0.9 % saline, ACR and ACR + CP groups received 30 mg/kg ACR by intraperitoneal injection. In addition, CP and ACR + CP groups also received 200 µg/kg CP. Gait analysis and hind limb splay were measured weekly to analyze neurobehavioral changes. The calpain activity and the changes of NFs protein levels in spinal cord are determined. Compared with control group, body weight of rats in ACR group decreased by 11.3 % (P < 0.01), while in ACR + CP group body weight increased significantly by 8.3 % (P < 0.01) compared with ACR group by the end of the 4th week; gait score of rats in both ACR and ACR + CP groups increased significantly by 167 % and 100 % (P < 0.01) compared with control group, while it decreased significantly by 25.1 % (P < 0.01) in ACR + CP group compared with ACR group; the distance of hind limb splay in both ACR and ACR + CP groups increased by 76.7 % and 49.5 % (P < 0.01) compared with control group, while it decreased by 15.4 % (P < 0.01) in ACR + CP group compared with ACR group; calpain activity of spinal cord at ACR and ACR + CP groups increased significantly by 14.9 % and 10.0 % (P < 0.01) compared with control group, while it decreased 4.2 % (P < 0.01) in ACR + CP group compared with ACR group; compared with control group, the levels of light NF (NF-L), medium NF (NF-M) and heavy NF (NF-H) subunits increased by 81.2 %, 263.6 % and 22.6 % (P < 0.01) in the supernatant of ACR group in spinal cord tissue and increased by 28

  2. Giant Axonal Neuropathy Among Two Siblings - A Case Report

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    John Jhon. K

    2001-01-01

    Full Text Available Giant axonal neuropathy is a rate disorder with an autosomal recessive inheritance. It should be differentiated from toxic neuropathies, and hereditary degenerative disorders of nervous system like Friedreich′s ataxia and HMSN. Thick curly hair, though may not be present always is a useful clinical clue to identify cases. Prognosis is generally poor though course of the illness is variable. We report here a clinically and hisopathologically characteristic familial case of giant axonal neuropathy, which occurred in a 17-year-old boy, and his 21-year-old sister.

  3. Uncovering sensory axonal dysfunction in asymptomatic type 2 diabetic neuropathy.

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    Sung, Jia-Ying; Tani, Jowy; Chang, Tsui-San; Lin, Cindy Shin-Yi

    2017-01-01

    This study investigated sensory and motor nerve excitability properties to elucidate the development of diabetic neuropathy. A total of 109 type 2 diabetes patients were recruited, and 106 were analyzed. According to neuropathy severity, patients were categorized into G0, G1, and G2+3 groups using the total neuropathy score-reduced (TNSr). Patients in the G0 group were asymptomatic and had a TNSr score of 0. Sensory and motor nerve excitability data from diabetic patients were compared with data from 33 healthy controls. Clinical assessment, nerve conduction studies, and sensory and motor nerve excitability testing data were analyzed to determine axonal dysfunction in diabetic neuropathy. In the G0 group, sensory excitability testing revealed increased stimulus for the 50% sensory nerve action potential (Pmotor excitability only had significantly increased stimulus for the 50% compound motor nerve action potential (Pdevelopment of axonal dysfunction in sensory axons occurred prior to and in a different fashion from motor axons. Additionally, sensory nerve excitability tests can detect axonal dysfunction even in asymptomatic patients. These insights further our understanding of diabetic neuropathy and enable the early detection of sensory axonal abnormalities, which may provide a basis for neuroprotective therapeutic approaches.

  4. Sodium Channels, Mitochondria, and Axonal Degeneration in Peripheral Neuropathy.

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    Persson, Anna-Karin; Hoeijmakers, Janneke G J; Estacion, Mark; Black, Joel A; Waxman, Stephen G

    2016-05-01

    Peripheral neuropathy results from damage to peripheral nerves and is often accompanied by pain in affected limbs. Treatment represents an unmet medical need and a thorough understanding of the mechanisms underlying axonal injury is needed. Longer nerve fibers tend to degenerate first (length-dependence), and patients carrying pathogenic mutations throughout life usually become symptomatic in mid- or late-life (time-dependence). The activity of voltage-gated sodium channels can contribute to axonal injury and sodium channel gain-of-function mutations have been linked to peripheral neuropathy. Recent studies have implicated sodium channel activity, mitochondrial compromise, and reverse-mode Na(+)/Ca(2+) exchange in time- and length-dependent axonal injury. Elucidation of molecular mechanisms underlying axonal injury in peripheral neuropathy may provide new therapeutic strategies for this painful and debilitating condition.

  5. Uncovering sensory axonal dysfunction in asymptomatic type 2 diabetic neuropathy

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    Sung, Jia-Ying; Tani, Jowy; Chang, Tsui-San; Lin, Cindy Shin-Yi

    2017-01-01

    This study investigated sensory and motor nerve excitability properties to elucidate the development of diabetic neuropathy. A total of 109 type 2 diabetes patients were recruited, and 106 were analyzed. According to neuropathy severity, patients were categorized into G0, G1, and G2+3 groups using the total neuropathy score-reduced (TNSr). Patients in the G0 group were asymptomatic and had a TNSr score of 0. Sensory and motor nerve excitability data from diabetic patients were compared with data from 33 healthy controls. Clinical assessment, nerve conduction studies, and sensory and motor nerve excitability testing data were analyzed to determine axonal dysfunction in diabetic neuropathy. In the G0 group, sensory excitability testing revealed increased stimulus for the 50% sensory nerve action potential (P<0.05), shortened strength-duration time constant (P<0.01), increased superexcitability (P<0.01), decreased subexcitability (P<0.05), decreased accommodation to depolarizing current (P<0.01), and a trend of decreased accommodation to hyperpolarizing current in threshold electrotonus. All the changes progressed into G1 (TNSr 1–8) and G2+3 (TNSr 9–24) groups. In contrast, motor excitability only had significantly increased stimulus for the 50% compound motor nerve action potential (P<0.01) in the G0 group. This study revealed that the development of axonal dysfunction in sensory axons occurred prior to and in a different fashion from motor axons. Additionally, sensory nerve excitability tests can detect axonal dysfunction even in asymptomatic patients. These insights further our understanding of diabetic neuropathy and enable the early detection of sensory axonal abnormalities, which may provide a basis for neuroprotective therapeutic approaches. PMID:28182728

  6. Antiretroviral Therapy-Associated Acute Motor and Sensory Axonal Neuropathy

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    Kimberly N. Capers

    2011-01-01

    Full Text Available Guillain-Barré syndrome (GBS has been reported in HIV-infected patients in association with the immune reconstitution syndrome whose symptoms can be mimicked by highly active antiretroviral therapy (HAART-mediated mitochondrial toxicity. We report a case of a 17-year-old, HIV-infected patient on HAART with a normal CD4 count and undetectable viral load, presenting with acute lower extremity weakness associated with lactatemia. Electromyography/nerve conduction studies revealed absent sensory potentials and decreased compound muscle action potentials, consistent with a diagnosis of acute motor and sensory axonal neuropathy. Lactatemia resolved following cessation of HAART; however, neurological deficits minimally improved over several months in spite of immune modulatory therapy. This case highlights the potential association between HAART, mitochondrial toxicity and acute axonal neuropathies in HIV-infected patients, distinct from the immune reconstitution syndrome.

  7. Pili canaliculi as manifestation of giant axonal neuropathy*

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    de Almeida Jr., Hiram Larangeira; Garcias, Gilberto; Silva, Ricardo Marques e; Batista, Stela Laner; Pasetto, Fernanda

    2016-01-01

    Giant axonal neuropathy is a rare autosomal recessive neurodegenerative disease. The condition is characterized by neurons with abnormally large axons due to intracellular filament accumulation. The swollen axons affect both the peripheral and central nervous system. A 6-year old female patient had been referred to a geneticist reporting problems with walking and hypotonia. At the age of 10, she became wheelchair dependent. Scanning electron microscopy of a curly hair classified it as pili canaliculi. GAN gene sequencing demonstrated mutation c.1456G>A (p.GLU486LYS). At the age of 12, the patient died due to respiratory complications. Dermatologists should be aware of this entity since hair changes are considered suggestive of GAN.

  8. Pyridoxine neuropathy in rats: specific degeneration of sensory axons.

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    Windebank, A J; Low, P A; Blexrud, M D; Schmelzer, J D; Schaumburg, H H

    1985-11-01

    When rats received pyridoxine in doses large enough to cause neuropathy in humans, the animals developed gait ataxia that subsided after the toxin was withdrawn. By using quantitative histologic techniques, we found axonal degeneration of sensory system fibers and that the fibers derived from the ventral root were spared. Although the degeneration approached the dorsal root ganglion, neurons in the ganglion did not degenerate. We found no early decrease in oxygen consumption of nerve, suggesting that impaired oxidative metabolism was not the primary event.

  9. New form of autosomal-recessive axonal hereditary sensory motor neuropathy.

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    Eckhardt, S M; Hicks, E M; Herron, B; Morrison, P J; Aicardi, J

    1998-09-01

    Two siblings, a male and a female, had severe axonal neuropathy and sideroblastic anemia. Despite a distinct clinical picture with areflexia, ataxia, hypotonia, optic atrophy, and progressive sensory neural hearing loss, no definite diagnosis could be reached and the older sibling died at 6 years of age of respiratory failure. It is proposed that the two affected siblings have a new form of autosomal-recessive axonal hereditary sensory motor neuropathy.

  10. Defective axonal transport: A common pathological mechanism in inherited and acquired peripheral neuropathies.

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    Prior, Robert; Van Helleputte, Lawrence; Benoy, Veronick; Van Den Bosch, Ludo

    2017-09-01

    Peripheral neuropathies are characterized by a progressive and length-dependent loss of peripheral nerve function. This can be caused either by genetic defects, classified as 'inherited peripheral neuropathies', or they can be acquired throughout life. In that case, the disease is caused by various insults such as toxins and mechanical injuries, or it can arise secondary to medical conditions such as metabolic disorders, nutritional deficiencies, inflammation and infections. Peripheral neuropathies are not only very heterogeneous in etiology, but also in their pathology and clinical presentation. A commonality amongst all peripheral neuropathies is that no pharmacological disease-modifying therapies currently exist that can reverse or cure these diseases. Moreover, the length-dependent nature of the disease, affecting the longest nerves at the most distal sites, suggests an important role for disturbances in axonal transport, directly or indirectly linked to alterations in the cytoskeleton. In this review, we will give a systematic overview of the main arguments for the involvement of axonal transport defects in both inherited and acquired peripheral neuropathies. In addition, we will discuss the possible therapeutic strategies that can potentially counteract these disturbances, as this particular pathway might be a promising strategy to find a cure. Since counteracting axonal transport defects could limit the axonal degeneration and could be a driving force for neuronal regeneration, the benefits might be twofold. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Truncated HSPB1 causes axonal neuropathy and impairs tolerance to unfolded protein stress

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    Emil Ylikallio

    2015-06-01

    General significance: sHSPs have important roles in prevention of protein aggregates that induce toxicity. We showed that C-terminal part of HSPB1 is critical for tolerance of unfolded protein stress, and when lacking causes axonal neuropathy in patients.

  12. Pure motor axonal neuropathy triggered by antituberculous therapy in an undiagnosed case of acute intermittent porphyria.

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    Babar, Masood Uz Zaman; Hakeem, Haris; Khan, Sara

    2017-03-27

    A man aged 22 years misdiagnosed as suffering from recurrent abdominal tuberculosis, in view of recurrent abdominal pain was treated for abdominal tuberculosis in the past. The patient was prescribed antituberculous therapy. 2 months after starting treatment, he developed progressive weakness of all 4 limbs. Electrodiagnostic examination revealed an acute severe motor axonal neuropathy. Further workup revealed elevated porphyrin precursors in urine.

  13. Aberrant Schwann cell lipid metabolism linked to mitochondrial deficits leads to axon degeneration and neuropathy.

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    Viader, Andreu; Sasaki, Yo; Kim, Sungsu; Strickland, Amy; Workman, Cayce S; Yang, Kui; Gross, Richard W; Milbrandt, Jeffrey

    2013-03-06

    Mitochondrial dysfunction is a common cause of peripheral neuropathy. Much effort has been devoted to examining the role played by neuronal/axonal mitochondria, but how mitochondrial deficits in peripheral nerve glia (Schwann cells [SCs]) contribute to peripheral nerve diseases remains unclear. Here, we investigate a mouse model of peripheral neuropathy secondary to SC mitochondrial dysfunction (Tfam-SCKOs). We show that disruption of SC mitochondria activates a maladaptive integrated stress response (ISR) through the actions of heme-regulated inhibitor (HRI) kinase, and causes a shift in lipid metabolism away from fatty acid synthesis toward oxidation. These alterations in SC lipid metabolism result in depletion of important myelin lipid components as well as in accumulation of acylcarnitines (ACs), an intermediate of fatty acid β-oxidation. Importantly, we show that ACs are released from SCs and induce axonal degeneration. A maladaptive ISR as well as altered SC lipid metabolism are thus underlying pathological mechanisms in mitochondria-related peripheral neuropathies.

  14. Mitochondrial biogenesis and fission in axons in cell culture and animal models of diabetic neuropathy.

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    Vincent, Andrea M; Edwards, James L; McLean, Lisa L; Hong, Yu; Cerri, Federica; Lopez, Ignazio; Quattrini, Angelo; Feldman, Eva L

    2010-10-01

    Mitochondrial-mediated oxidative stress in response to high glucose is proposed as a primary cause of dorsal root ganglia (DRG) neuron injury in the pathogenesis of diabetic neuropathy. In the present study, we report a greater number of mitochondria in both myelinated and unmyelinated dorsal root axons in a well-established model of murine diabetic neuropathy. No similar changes were seen in younger diabetic animals without neuropathy or in the ventral motor roots of any diabetic animals. These findings led us to examine mitochondrial biogenesis and fission in response to hyperglycemia in the neurites of cultured DRG neurons. We demonstrate overall mitochondrial biogenesis via increases in mitochondrial transcription factors and increases in mitochondrial DNA in both DRG neurons and axons. However, this process occurs over a longer time period than a rapidly observed increase in the number of mitochondria in DRG neurites that appears to result, at least in part, from mitochondrial fission. We conclude that during acute hyperglycemia, mitochondrial fission is a prominent response, and excessive mitochondrial fission may result in dysregulation of energy production, activation of caspase 3, and subsequent DRG neuron injury. During more prolonged hyperglycemia, there is evidence of compensatory mitochondrial biogenesis in axons. Our data suggest that an imbalance between mitochondrial biogenesis and fission may play a role in the pathogenesis of diabetic neuropathy.

  15. Severe acute axonal neuropathy following treatment with arsenic trioxide for acute promyelocytic leukemia: a case report

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    Marcus Kuhn

    2016-05-01

    Full Text Available Peripheral neuropathy is a common complication of arsenic toxicity. Symptoms are usually mild and reversible following discontinuation of treatment. A more severe chronic sensorimotor polyneuropathy characterized by distal axonal-loss neuropathy can be seen in chronic arsenic exposure. The clinical course of arsenic neurotoxicity in patients with coexistence of thiamine deficiency is only anecdotally known but this association may potentially lead to severe consequences. We describe a case of acute irreversible axonal neuropathy in a patient with hidden thiamine deficiency who was treated with a short course of arsenic trioxide for acute promyelocytic leukemia. Thiamine replacement therapy and arsenic trioxide discontinuation were not followed by neurological recovery and severe polyneuropathy persisted at 12-month follow-up. Thiamine plasma levels should be measured in patients who are candidate to arsenic trioxide therapy. Prophylactic administration of vitamin B1 may be advisable. The appearance of polyneuropathy signs early during the administration of arsenic trioxide should prompt electrodiagnostic testing to rule out a pattern of axonal neuropathy which would need immediate discontinuation of arsenic trioxide.

  16. Asymmetric Acute Motor Axonal Neuropathy With Unilateral Tongue Swelling Mimicking Stroke.

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    Chi, Man Sum; Ng, Shi Hon; Chan, Lok Yiu

    2016-11-01

    A 60-year-old man presented with acute onset of left hemiparesis and left hypoglossal nerve palsy with ipsilateral tongue swelling. He then progressed to tetraparesis in a few days. Cerebrospinal fluid showed cell protein dissociation. A nerve conduction study showed motor axonal neuropathy with sensory sparing. A subsequent blood test revealed anti-GD1b IgG antibody positivity. He was diagnosed to have acute motor axonal neuropathy (AMAN) and treated with a course of intravenous immunoglobulin with slow improvement. This is probably the first AMAN with asymmetrical presentation mimicking stroke reported in the literature in detail. The anti-GD1b IgG antibody is also not commonly associated with AMAN.

  17. Acute Motor Axonal Neuropathy (Aman) With Motor Conduction Blocks In Childhood; Case Report

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    Yildirim, Serhan; Adviye, Rahşan; Gül, Hakan Levent; Türk Börü, Ülkü

    2016-01-01

    Objective Acute motor axonal neuropathy (AMAN), characterized with decreased compound muscle action potentials (CMAP) and absence of demyelinating findings in electrophysiological studies, is a subtype of Guillain-Barre Syndrome (GBS). A 4 yr-old male patient presented with ascending weakness, dysarthria and dysphagia to İstanbul Dr. Lütfi Kırdar Kartal Training and Research Hospital Neurology outpatient for three days to in 2012. Dysphonia, restricted eye movements, flaccid tetraplegia and a...

  18. DNA Single-Strand Break Repair and Spinocerebellar Ataxia with Axonal Neuropathy-1

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    Caldecott, K. W.

    2007-01-01

    DNA single-strand breaks (SSBs) are the commonest DNA lesions arising spontaneously in cells, and if not repaired may block transcription or may be converted into potentially lethal/clastogenic DNA double-strand breaks (DSBs). Recently, evidence has emerged that defects in the rapid repair of SSBs preferentially impact the nervous system. In particular, spinocerebellar ataxia with axonal neuropathy (SCAN1) is a human disease that is associated with mutation of TDP1 (tyrosyl DNA phosphodiester...

  19. DNA single-strand break repair and spinocerebellar ataxia with axonal neuropathy-1

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    El-Khamisy, S.F.; Caldecott, K. W.

    2007-01-01

    DNA single-strand breaks (SSBs) are the commonest DNA lesions arising spontaneously in cells, and if not repaired may block transcription or may be converted into potentially lethal/clastogenic DNA double-strand breaks (DSBs). Recently, evidence has emerged that defects in the rapid repair of SSBs preferentially impact the nervous system. In particular, spinocerebellar ataxia with axonal neuropathy (SCAN1) is a human disease that is associated with mutation of TDP1 (tyrosyl DNA phosphodiester...

  20. New mutations, genotype phenotype studies and manifesting carriers in giant axonal neuropathy

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    Houlden, Henry; Groves, Mike; Miedzybrodzka, Zosia; Roper, Helen; Willis, Tracey; Winer, John; Cole, Gaynor; Reilly, Mary M

    2007-01-01

    Giant axonal neuropathy (GAN; MIM 256850) is a severe childhood onset autosomal recessive sensorimotor neuropathy affecting both the peripheral nerves and the central nervous system. Bomont and colleagues identified a novel ubiquitously expressed gene they named Gigaxonin on chromosome 16q24 as the cause of GAN in a number of families. We analysed five families with GAN for mutations in the Gigaxonin gene and mutations were found in four families; three families had homozygous mutations, one had two compound heterozygous mutations and one family had no mutation identified. All families had the typical clinical features, kinky hair and nerve biopsy. We report some unusual clinical features associated with GAN and Gigaxonin mutations as well as confirm the heterogeneity in GAN and the identification of two families with manifesting carriers. PMID:17578852

  1. Giant axonal neuropathy alters the structure of keratin intermediate filaments in human hair.

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    Soomro, Asfia; Alsop, Richard J; Negishi, Atsuko; Kreplak, Laurent; Fudge, Douglas; Kuczmarski, Edward R; Goldman, Robert D; Rheinstädter, Maikel C

    2017-04-01

    Giant axonal neuropathy (GAN) follows an autosomal recessive genetic inheritance and impedes the peripheral and central nervous system due to axonal swellings that are packed with neurofilaments. The patients display a number of phenotypes, including hypotonia, muscle weakness, decreased reflexes, ataxia, seizures, intellectual disability, pale skin and often curled hair. We used X-ray diffraction and tensile testing to determine potential changes to the structure of keratin intermediate filaments (IFs) in the hair of patients with GAN. A statistically significant decrease in the 47 and the 27 Å diffraction signals were observed. Tensile tests determined that the hair was slightly stiffer, stronger and more extensible in GAN patients. These results suggest that the structure of keratin IFs in hair is altered in GAN, and the findings are compatible with an increased positional disorder of the keratin tetramers within the hair fibres. © 2017 The Author(s).

  2. A Case of Acute Motor Axonal Neuropathy Mimicking Brain Death and Review of the Literature.

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    Ravikumar, Sandhya; Poysophon, Poysophon; Poblete, Roy; Kim-Tenser, May

    2016-01-01

    We describe a case report of fulminant Guillain-Barré syndrome (GBS) mimicking brain death. A previously healthy 60-year-old male was admitted to the neurointensive care unit after developing rapidly progressive weakness and respiratory failure. On presentation, the patient was found to have absent brainstem and spinal cord reflexes resembling that of brain death. Acute motor axonal neuropathy, a subtype of GBS, was diagnosed by cerebrospinal fluid and nerve conduction velocity testing. An electroencephalogram showed that the patient had normal, appropriately reactive brain function. Transcranial Doppler (TCD) ultrasound showed appropriate blood flow to the brain. GBS rarely presents with weakness so severe as to mimic brain death. This article provides a review of similar literature. This case demonstrates the importance of performing a proper brain death examination, which includes evaluation for irreversible cerebral injury, exclusion of any confounding conditions, and performance of tests such as electroencephalography and TCDs when uncertainty exists about the reliability of the clinical exam.

  3. Recent advances in the genetics of hereditary axonal sensory-motor neuropathies type 2.

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    Ajroud-Driss, Senda; Deng, Han-Xiang; Siddique, Teepu

    2011-06-01

    Hereditary axonal motor and sensory neuropathies or Charcot-Marie-Tooth disease type 2 (CMT2) are characterized clinically by distal muscle weakness and atrophy, sensory loss, and foot deformities. Conduction velocities are usually in the normal range or mildly slowed. The majority of CMT2 are autosomal-dominant but autosomal-recessive forms have been described. The number of genes associated with CMT2 have significantly increased in the past decade, with the gene causing CMT2C/SPSMA being the last one discovered. More than 10 genes are now associated with different subtypes of CMT2, which are classified from CMT2A to CMT2N. These genes have distinct functions, but some appear to be involved in common biological pathways, therefore, providing important clues for understanding the pathogenic mechanism of these heterogeneous disorders.

  4. Mitochondrial abnormality in sensory, but not motor, axons in paclitaxel-evoked painful peripheral neuropathy in the rat.

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    Xiao, W H; Zheng, H; Zheng, F Y; Nuydens, R; Meert, T F; Bennett, G J

    2011-12-29

    The dose-limiting side effect of the anti-neoplastic agent, paclitaxel, is a chronic distal symmetrical peripheral neuropathy that produces sensory dysfunction (hypoesthesia and neuropathic pain) but little or no distal motor dysfunction. Similar peripheral neuropathies are seen with chemotherapeutics in the vinca alkaloid, platinum-complex, and proteasome inhibitor classes. Studies in rats suggest that the cause is a mitotoxic effect on axonal mitochondria. If so, then the absence of motor dysfunction may be due to mitotoxicity that affects sensory axons but spares motor axons. To investigate this, paclitaxel exposure levels in the dorsal root, ventral root, dorsal root ganglion, peripheral nerve, and spinal cord were measured, and the ultrastructure and the respiratory function of mitochondria in dorsal roots and ventral roots were compared. Sensory and motor axons in the roots and nerve had comparably low exposure to paclitaxel and exposure in the spinal cord was negligible. However, sensory neurons in the dorsal root ganglion had a very high and remarkably persistent (up to 10 days or more after the last injection) exposure to paclitaxel. Paclitaxel evoked a significant increase in the incidence of swollen and vacuolated mitochondria in the myelinated and unmyelinated sensory axons of the dorsal root (as seen previously in the peripheral nerve) but not in the motor axons of the ventral root. Stimulated mitochondrial respiration in the dorsal root was significantly depressed in paclitaxel-treated animals examined 2-4 weeks after the last injection, whereas respiration in the ventral root was normal. We conclude that the absence of motor dysfunction in paclitaxel-evoked peripheral neuropathy may be due to the absence of a mitotoxic effect in motor neuron axons, whereas the sensory dysfunction may be due to a mitotoxic effect resulting from the primary afferent neuron's cell body being exposed to high and persistent levels of paclitaxel.

  5. Sensory neuropathy in progressive motor neuronopathy (pmn) mice is associated with defects in microtubule polymerization and axonal transport.

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    Schäfer, Michael K; Bellouze, Sarah; Jacquier, Arnaud; Schaller, Sébastien; Richard, Laurence; Mathis, Stéphane; Vallat, Jean-Michel; Haase, Georg

    2016-08-04

    Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter mice and electron microscopy, we demonstrate axonal discontinuities, bead-like spheroids and ovoids in pmn suralis nerves indicating prominent sensory neuropathy. The axonal alterations qualitatively resemble those in phrenic motor nerves but do not culminate in the loss of myelinated fibers. We further show that the pmn mutation decreases the level of TBCE, impedes microtubule polymerization in dorsal root ganglion (DRG) neurons and causes progressive loss of microtubules in large and small caliber suralis axons. Live imaging of axonal transport using GFP-tagged tetanus toxin C-fragment (GFP-TTC) demonstrates defects in microtubule-based transport in pmn DRG neurons, providing a potential explanation for the axonal alterations in sensory nerves. This study unravels sensory neuropathy as a pathological feature of mouse pmn, and discusses the potential contribution of cytoskeletal defects to sensory neuropathy in human motor neuron disease.

  6. Axonal loss and blood flow disturbances in the natural course of indirect traumatic optic neuropathy

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    SHI Wei; WANG Huai-zhou; SONG Wei-xian; YANG Wen-li; LI Wei-ye; WANG Ning-li

    2013-01-01

    Background Indirect traumatic optic neuropathy (TON) is an acute injury of the optic nerve associated with severe visual dysfunction,which may be a result of secondary mechanical injury and vascular disorder of the optic nerve due to trauma.We analyzed the natural course of axonal loss and blood flow disturbances in patients with indirect TON to find a possible therapeutic window.Methods A cohort of 54 patients with indirect TON recruited between October 2008 and October 2010 at Beijing Tongren Hospital was retrospectively analyzed.The patients were divided into no light perception group (NLP) and better than NLP (btNLP) group.Specifically,the thickness of the retinal nerve fiber layer (RNFL) measured by spectral domain optical coherence tomography (SD-OCT),and hemodynamic parameters of the ophthalmic artery (OA),central retinal artery (CRA) and posterior ciliary artery (PCA) were determined.Results Two weeks after injury,there was a statistically significant decrease in the thickness of RNFL in the btNLP group as compared with the fellow control eyes (P <0.05).In contrast,in the NLP group,RNFL thickness slightly increased for 2 weeks following injury,then overtly reduced after 4 weeks (P <0.05).Peak systolic velocity (PSV) of CRA was significantly decreased 4 weeks after injury (P <0.05) in both the NLP group and btNLP group (P <0.05).The thickness of RNFL in the NLP group was negatively correlated with PSV of CRA after 1 week of injury (P <0.05,r=-0.962).Conclusions SD-OCT is a useful supplement in detecting the axonal loss in TON.The dynamic change of the thickness of RNFL appears to correlate with the hemodynamic disturbances in the natural course of TON.The first 2 weeks following an injury is critical and should be considered as the therapeutic window for TON patients.

  7. Ischemic optic neuropathy as a model of neurodegenerative disorder: A review of pathogenic mechanism of axonal degeneration and the role of neuroprotection.

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    Khalilpour, Saba; Latifi, Shahrzad; Behnammanesh, Ghazaleh; Majid, Amin Malik Shah Abdul; Majid, Aman Shah Abdul; Tamayol, Ali

    2017-04-15

    Optic neuropathy is a neurodegenerative disease which involves optic nerve injury. It is caused by acute or intermittent insults leading to visual dysfunction. There are number of factors, responsible for optic neuropathy, and the optic nerve axon is affected in all type which causes the loss of retinal ganglion cells. In this review we will highlight various mechanisms involved in the cell loss cascades during axonal degeneration as well as ischemic optic neuropathy. These mechanisms include oxidative stress, excitotoxicity, angiogenesis, neuroinflammation and apoptosis following retinal ischemia. We will also discuss the effect of neuroprotective agents in attenuation of the negative effect of factors involve in the disease occurrence and progression.

  8. A Case of Acute Motor Axonal Neuropathy Mimicking Brain Death and Review of the Literature

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    Sandhya eRavikumar

    2016-04-01

    Full Text Available We describe a case report of fulminant Guillain-Barré syndrome mimicking brain death. A previously healthy 60-year-old male was admitted to the neurointensive care unit after developing rapidly progressive weakness and respiratory failure. On presentation, the patient was found to have absent brainstem and spinal cord reflexes resembling that of brain death. Acute motor axonal neuropathy (AMAN, a subtype of Guillain-Barré syndrome, was diagnosed by cerebrospinal fluid and nerve conduction velocity testing. An electroencephalogram showed that the patient had normal, appropriately reactive brain function. Transcranial Doppler ultrasound showed appropriate blood flow to the brain. Guillain-Barré syndrome rarely presents with weakness so severe as to mimic brain death. This article provides a review of similar literature. This case demonstrates the importance of performing a proper brain death examination, which includes evaluation for irreversible cerebral injury, exclusion of any confounding conditions, and performance of tests such as electroencephalography and transcranial dopplers when uncertainty exists about the reliability of the clinical exam.

  9. Abnormal intermediate filament organization alters mitochondrial motility in giant axonal neuropathy fibroblasts.

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    Lowery, Jason; Jain, Nikhil; Kuczmarski, Edward R; Mahammad, Saleemulla; Goldman, Anne; Gelfand, Vladimir I; Opal, Puneet; Goldman, Robert D

    2016-02-15

    Giant axonal neuropathy (GAN) is a rare disease caused by mutations in the GAN gene, which encodes gigaxonin, an E3 ligase adapter that targets intermediate filament (IF) proteins for degradation in numerous cell types, including neurons and fibroblasts. The cellular hallmark of GAN pathology is the formation of large aggregates and bundles of IFs. In this study, we show that both the distribution and motility of mitochondria are altered in GAN fibroblasts and this is attributable to their association with vimentin IF aggregates and bundles. Transient expression of wild-type gigaxonin in GAN fibroblasts reduces the number of IF aggregates and bundles, restoring mitochondrial motility. Conversely, silencing the expression of gigaxonin in control fibroblasts leads to changes in IF organization similar to that of GAN patient fibroblasts and a coincident loss of mitochondrial motility. The inhibition of mitochondrial motility in GAN fibroblasts is not due to a global inhibition of organelle translocation, as lysosome motility is normal. Our findings demonstrate that it is the pathological changes in IF organization that cause the loss of mitochondrial motility.

  10. Cryptic Amyloidogenic Elements in the 3′ UTRs of Neurofilament Genes Trigger Axonal Neuropathy

    Science.gov (United States)

    Rebelo, Adriana P.; Abrams, Alexander J.; Cottenie, Ellen; Horga, Alejandro; Gonzalez, Michael; Bis, Dana M.; Sanchez-Mejias, Avencia; Pinto, Milena; Buglo, Elena; Markel, Kasey; Prince, Jeffrey; Laura, Matilde; Houlden, Henry; Blake, Julian; Woodward, Cathy; Sweeney, Mary G.; Holton, Janice L.; Hanna, Michael; Dallman, Julia E.; Auer-Grumbach, Michaela; Reilly, Mary M.; Zuchner, Stephan

    2016-01-01

    Abnormal protein aggregation is observed in an expanding number of neurodegenerative diseases. Here, we describe a mechanism for intracellular toxic protein aggregation induced by an unusual mutation event in families affected by axonal neuropathy. These families carry distinct frameshift variants in NEFH (neurofilament heavy), leading to a loss of the terminating codon and translation of the 3′ UTR into an extra 40 amino acids. In silico aggregation prediction suggested the terminal 20 residues of the altered NEFH to be amyloidogenic, which we confirmed experimentally by serial deletion analysis. The presence of this amyloidogenic motif fused to NEFH caused prominent and toxic protein aggregates in transfected cells and disrupted motor neurons in zebrafish. We identified a similar aggregation-inducing mechanism in NEFL (neurofilament light) and FUS (fused in sarcoma), in which mutations are known to cause aggregation in Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis, respectively. In summary, we present a protein-aggregation-triggering mechanism that should be taken into consideration during the evaluation of stop-loss variants. PMID:27040688

  11. Mechanisms of acrylamide induced rodent carcinogenesis.

    Science.gov (United States)

    Klaunig, James E; Kamendulis, Lisa M

    2005-01-01

    observed carcinogenicity of acrylamide. SHE cell studies showed that glutathione (GSH) modulation by acrylamide was important in the cell transformation process. Treatment with a sulfhydryl donor compound (NAC) reduced acrylamide transformation while depletion of GSH (BSO) resulted in an enhancement of transformation. In summary, acrylamide caused both an increase in DNA synthesis and DNA damage in mammalian tissues and cells suggesting that DNA reactivity and cell proliferation, in concert, may contribute to the observed acrylamide-induced carcinogenicity in the rat and has implication on the possible risk for human neoplasm development.

  12. The Activation of RAGE and NF-KB in Nerve Biopsies of Patients with Axonal and Vasculitic Neuropathy.

    Science.gov (United States)

    Bekircan-Kurt, Can Ebru; Tan, Ersin; Erdem Özdamar, Sevim

    2015-09-01

    The receptor for advanced glycation end products (RAGE) is a pattern recognition receptor expressed in tissues and cells, which plays a role in immunity. The activation of RAGE results in the translocation of nuclear factor kappa B (NF-κB) to the nucleus for expression of proinflammatory molecules. The role of the RAGE pathway in the pathogenesis of diabetic complications is well determined. We aimed to investigate the role of the RAGE pathway in axonal and vasculitic neuropathy. We immunoreacted nerve biopsy samples from 17 axonal neuropathy (AN), 11 vasculitic neuropathy (VN) and 12 hereditary neuropathy (as a control group) with liability to pressure palsy (HNPP) patients with antibodies to NF-κB and RAGE. Subsequently, we performed double staining with the antibodies to NF-κB or RAGE and T cells, macrophages and Schwann cells. RAGE and NF-κB immunoreactivities were higher in the perivascular cuff and in endoneurial cells in VN than in AN and HNPP. Although there is no significant difference, nerve biopsies with AN showed higher NFκB and RAGE immunoreactivities than HNPP. The colocalization study showed that most of the NFκB- and RAGE-positive cells were CD8 (+) T cells in VN. In AN, all NFκB- and RAGE-positive cells were macrophages, whereas all NFκB- and RAGE-positive cells were Schwann cells in HNPP. The activation of the RAGE pathway predominant in CD8 (+) T cells underscores its role in VN. In AN patients, the immunoreactivity to NFκB and RAGE in macrophages may support their role in axonal degeneration without inflammatory milieu.

  13. Axonal neuropathy in female carriers of the fragile X premutation with fragile x-associated tremor ataxia syndrome.

    Science.gov (United States)

    Ram, Suresh; Devapriya, Inoka A; Fenton, Grace; Mcvay, Lindsey; Nguyen, Danh V; Tassone, Flora; Maselli, Ricardo A; Hagerman, Randi J

    2015-08-01

    In this study we examined whether females with the fragile X-associated tremor ataxia syndrome (FXTAS) and non-FXTAS premutation carriers have electrophysiological signs of underlying peripheral neuropathy. Nerve conduction studies (NCS) were performed on 19 women with FXTAS, 20 non-FXTAS carriers, and 26 age-matched controls. The results were compared with existing data on corresponding male carriers. Women with FXTAS and non-FXTAS carriers had reduced sensory nerve action potential amplitudes. Also, there was a strong trend for reduced compound muscle action potential amplitudes in women with FXTAS, but not in non-FXTAS carriers. No significant slowing of nerve conduction velocities, prolongation of F-wave latencies, or associations with molecular measures was observed. This study suggests an underlying axonal neuropathy in women with FXTAS. However, in comparison to men with FXTAS, the NCS abnormalities in women were less severe, possibly due to the effect of a normal X chromosome. © 2014 Wiley Periodicals, Inc.

  14. GRS defective axonal distribution as a potential contributor to distal spinal muscular atrophy type V pathogenesis in a new model of GRS-associated neuropathy.

    Science.gov (United States)

    Seo, Ah Jung; Park, Byung Sun; Jung, Junyang

    2014-11-01

    Distal spinal muscular atrophy type V (dSMA-V), a hereditary axonal neuropathy, is a glycyl-tRNA synthetase (GRS)-associated neuropathy caused by a mutation in GRS. In this study, using an adenovirus vector system equipped with a neuron-specific promoter, we constructed a new GRS-associated neuropathy mouse model. We found that wild-type GRS (WT) is distributed in peripheral axons, dorsal root ganglion (DRG) cell bodies, central axon terminals and motor neuron cell bodies in the mouse model. In contrast, the L129P mutant GRS was localized in DRG and motor neuron cell bodies. Thus, we propose that the disease-causing L129P mutant is linked to a distribution defect in peripheral nerves in vivo.

  15. Axonal neuropathy with optic atrophy is caused by mutations in mitofusin 2

    NARCIS (Netherlands)

    S. Zuchner; P. de Jonghe; A. Jordanova; K.G. Claeys; V. Guergueltcheva; S. Cherninkova; S.R. Hamilton; G. van Stavern; K.M. Krajewski; J. Stajich; I. Tournev; K. Verhoeven; C.T. Langerhorst; M. de Visser; F. Baas; T. Bird; V. Timmerman; M. Shy; J.M. Vance

    2006-01-01

    Objective: Charcot-Marie-Tooth (CMT) neuropathy with visual impairment due to optic atrophy has been designated as hereditary motor and sensory neuropathy type VI (HMSN VI). Reports of affected families have indicated autosomal dominant and recessive forms, but the genetic cause of this disease has

  16. Clinical pathological and genetic analysis of 2 cases of mitochondrial myopathy presented as acute motor axonal neuropathy

    Directory of Open Access Journals (Sweden)

    Hou-min YIN

    2014-06-01

    Full Text Available Background The main clinical manifestations of mitochondrial myopathy are chronic limb weakness and muscular soreness. Subclinical peripheral nerve injury is also reported, but acute axonal neuropathy.like syndrome concurrent with lactic acidosis is rare. In this paper the clinical features of 2 patients presenting as acute lactic acidosis and sudden muscle weakness were analyzed. Pathological changes and genetic mutations were detected.  Methods Electromyography (EMG and muscle biopsy were performed. Modified Gomori trichrome (MGT and succinodehydrogenase (SDH staining were used to identify pathological changes. Changes of ultra microstructure of muscular tissue were observed under electron microscope. Mitochondrial DNA (mtDNA full length sequencing was performed using 24 pairs of partially overlapping primers.  Results EMG showed a coexistence of neurogenic and myogenic changes. Dramatic decrease of motor nerve amplitude and moderately reduced sensory nerve amplitude were observed but nerve conduction velocity was normal in both patients. Impressive ragged red fibers were seen on MGT staining. Electron microscope showed dramatic mitochondrial abnormalities in Case 1 and paracrystaline inclusions in Case 2. mtDNA sequencing showed 3243A > G mutation in Case 1 and 8344A > G mutation in Case 2. Conclusions Mitochondrial myopathy can present as metabolic crisis like acute lactic acidosis, dyspnea and acute motor axonal neuropathy.like syndrome. It is a life.threatening phenotype that needs more attention. doi: 10.3969/j.issn.1672-6731.2014.06.007

  17. 4-Hydroxy-2-nonenal induces mitochondrial dysfunction and aberrant axonal outgrowth in adult sensory neurons that mimics features of diabetic neuropathy.

    Science.gov (United States)

    Akude, Eli; Zherebitskaya, Elena; Roy Chowdhury, Subir K; Girling, Kimberly; Fernyhough, Paul

    2010-01-01

    Modification of proteins by 4-hydroxy-2-nonenal (4-HNE) has been proposed to cause neurotoxicity in a number of neurodegenerative diseases, including distal axonopathy in diabetic sensory neuropathy. We tested the hypothesis that exposure of cultured adult rat sensory neurons to 4-HNE would result in the formation of amino acid adducts on mitochondrial proteins and that this process would be associated with impaired mitochondrial function and axonal regeneration. In addition, we compared 4-HNE-induced axon pathology with that exhibited by neurons isolated from diabetic rats. Cultured adult rat dorsal root ganglion (DRG) sensory neurons were incubated with varying concentrations of 4-HNE. Cell survival, axonal morphology, and level of axon outgrowth were assessed. In addition, video microscopy of live cells, western blot, and immunofluorescent staining were utilized to detect protein adduct formation by 4-HNE and to localize actively respiring mitochondria. 4-HNE induced formation of protein adducts on cytoskeletal and mitochondrial proteins, and impaired axon regeneration by approximately 50% at 3 microM while having no effect on neuronal survival. 4-HNE initiated formation of aberrant axonal structures and caused the accumulation of mitochondria in these dystrophic structures. Neurons treated with 4-HNE exhibited a distal loss of active mitochondria. Finally, the distal axonopathy and the associated aberrant axonal structures generated by 4-HNE treatment mimicked axon pathology observed in DRG sensory neurons isolated from diabetic rats and replicated aspects of neurodegeneration observed in human diabetic sensory neuropathy.

  18. Vasculitic neuropathy.

    Science.gov (United States)

    Sampaio, Luzia; Silva, Lã Gia; Terroso, Georgina; Nadais, Goreti; Mariz, Eva; Ventura, Francisco

    2011-01-01

    Vasculitic neuropathy corresponds to the occurrence of vasculitis at the level of vasa nervorum, resulting in ischemic damage of the peripheral nerve and axonal degeneration. Vasculitic neuropathy commonly occurs in association with systemic diseases and may be the initial manifestation or arise in the course of established disease. Although rare, vasculitis can be confined to the peripheral nervous system - non-systemic vasculitic neuropathy. This paper aims to review the classification, diagnosis and treatment of vasculitic neuropathy.

  19. Peripheral Neuropathy in the Twitcher Mouse Involves the Activation of Axonal Caspase 3

    Directory of Open Access Journals (Sweden)

    Benjamin Smith

    2011-09-01

    Full Text Available Infantile Krabbe disease results in the accumulation of lipid-raft-associated galactosylsphingosine (psychosine, demyelination, neurodegeneration and premature death. Recently, axonopathy has been depicted as a contributing factor in the progression of neurodegeneration in the Twitcher mouse, a bona fide mouse model of Krabbe disease. Analysis of the temporal-expression profile of MBP (myelin basic protein isoforms showed unexpected increases of the 14, 17 and 18.5 kDa isoforms in the sciatic nerve of 1-week-old Twitcher mice, suggesting an abnormal regulation of the myelination process during early postnatal life in this mutant. Our studies showed an elevated activation of the pro-apoptotic protease caspase 3 in sciatic nerves of 15- and 30-day-old Twitcher mice, in parallel with increasing demyelination. Interestingly, while active caspase 3 was clearly contained in peripheral axons at all ages, we found no evidence of caspase accumulation in the soma of corresponding mutant spinal cord motor neurons. Furthermore, active caspase 3 was found not only in unmyelinated axons, but also in myelinated axons of the mutant sciatic nerve. These results suggest that axonal caspase activation occurs before demyelination and following a dying-back pattern. Finally, we showed that psychosine was sufficient to activate caspase 3 in motor neuronal cells in vitro in the absence of myelinating glia. Taken together, these findings indicate that degenerating mechanisms actively and specifically mediate axonal dysfunction in Krabbe disease and support the idea that psychosine is a pathogenic sphingolipid sufficient to cause axonal defects independently of demyelination.

  20. Peripheral neuropathy in the Twitcher mouse involves the activation of axonal caspase 3

    Directory of Open Access Journals (Sweden)

    Ernesto R Bongarzone

    2011-10-01

    Full Text Available Infantile Krabbe disease results in the accumulation of lipid-raft-associated galactosylsphingosine (psychosine, demyelination, neurodegeneration and premature death. Recently, axonopathy has been depicted as a contributing factor in the progression of neurodegeneration in the Twitcher mouse, a bona fide mouse model of Krabbe disease. Analysis of the temporal-expression profile of MBP (myelin basic protein isoforms showed unexpected increases of the 14, 17 and 18.5 kDa isoforms in the sciatic nerve of 1-week-old Twitcher mice, suggesting an abnormal regulation of the myelination process during early postnatal life in this mutant. Our studies showed an elevated activation of the pro-apoptotic protease caspase 3 in sciatic nerves of 15- and 30-day-old Twitcher mice, in parallel with increasing demyelination. Interestingly, while active caspase 3 was clearly contained in peripheral axons at all ages, we found no evidence of caspase accumulation in the soma of corresponding mutant spinal cord motor neurons. Furthermore, active caspase 3 was found not only in unmyelinated axons, but also in myelinated axons of the mutant sciatic nerve. These results suggest that axonal caspase activation occurs before demyelination and following a dying-back pattern. Finally, we showed that psychosine was sufficient to activate caspase 3 in motor neuronal cells in vitro in the absence of myelinating glia. Taken together, these findings indicate that degenerating mechanisms actively and specifically mediate axonal dysfunction in Krabbe disease and support the idea that psychosine is a pathogenic sphingolipid sufficient to cause axonal defects independently of demyelination.

  1. Novel High-Throughput Drug Screening Platform for Chemotherapy-Induced Axonal Neuropathy

    Science.gov (United States)

    2013-05-01

    COVERED 1 May 201 - 30 Apr 201 4. TITLE AND SUBTITLE : Novel High-Throughput Drug Screening Platform for Chemotherapy-Induced axonal...Introduction-page 1 Results- page 1,2,3 Conclusion-page 3 Introduction: Taxol is an antineoplastic agent, which is used for the treatment of

  2. A critical appraisal of the mild axonal peripheral neuropathy of late neurologic Lyme disease.

    Science.gov (United States)

    Wormser, Gary P; Strle, Franc; Shapiro, Eugene D; Dattwyler, Raymond J; Auwaerter, Paul G

    2017-02-01

    In older studies, a chronic distal symmetric sensory neuropathy was reported as a relatively common manifestation of late Lyme disease in the United States. However, the original papers describing this entity had notable inconsistencies and certain inexplicable findings, such as reports that this condition developed in patients despite prior antibiotic treatment known to be highly effective for other manifestations of Lyme disease. More recent literature suggests that this entity is seen rarely, if at all. A chronic distal symmetric sensory neuropathy as a manifestation of late Lyme disease in North America should be regarded as controversial and in need of rigorous validation studies before acceptance as a documented clinical entity. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Acquired inflammatory demyelinating neuropathies.

    Science.gov (United States)

    Ensrud, E R; Krivickas, L S

    2001-05-01

    The acquired demyelinating neuropathies can be divided into those with an acute onset and course and those with a more chronic course. The acute neuropathies present as Guillain-Barré syndrome and include acute inflammatory demyelinating polyradiculoneuropathy (AIDP), Miller Fisher syndrome, acute motor axonal neuropathy (AMAN), acute motor and sensory axonal neuropathy (AMSAN), and acute pandysautonomia. The chronic neuropathies are collectively known as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and include MADSAM (multifocal acquired demyelinating sensory and motor neuropathy, also know as Lewis-Sumner syndrome) and DADS (distal acquired demyelinating symmetric neuropathy) as variants. The clinical features, pathology, pathogenesis, diagnosis, treatment, rehabilitation, and prognosis of these neuropathies are discussed.

  4. Increased axonal regeneration and swellings in intraepidermal nerve fibers characterize painful phenotypes of diabetic neuropathy

    OpenAIRE

    Cheng, H.T.; Dauch, J.R.; Porzio, M.T.; Yanik, B.M.; Hsieh, W; Smith, A.G.; Singleton, J.R.; Feldman, E.L.

    2013-01-01

    We examined changes in intraepidermal nerve fibers (IENFs) to differentiate patients with diabetic neuropathy (DN) and neuropathic pain (DN-P) from those with DN without pain (DN-NOP). Punch skin biopsies were collected from the proximal thigh (PT) and distal leg (DL) of normal subjects (NS), patients with type 2 diabetes without evidence of DN (DM), or DN-P and DN-NOP patients. Protein gene product 9.5 (PGP) immunohistochemistry was used to quantify total IENF, and growth associated protein ...

  5. Disulfiram neuropathy.

    OpenAIRE

    1980-01-01

    Disulfiram (Antabuse) can produce neuropathy in daily doses of less than the usually recommended 500 mg. The four recent cases reported in this paper emphasize the need for greater recognition of this condition. Nerve biopsies showed axonal degeneration. The neuropathy is difficult to distinguish from that associated with ethanol abuse. Disulfiram neuropathy occurs after a variable latent period (mean 5 to 6 months) and progresses steadily. Slow improvement may occur when the drug's use is st...

  6. HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation.

    Science.gov (United States)

    Kim, Ji-Yon; Woo, So-Youn; Hong, Young Bin; Choi, Heesun; Kim, Jisoo; Choi, Hyunjung; Mook-Jung, Inhee; Ha, Nina; Kyung, Jangbeen; Koo, Soo Kyung; Jung, Sung-Chul; Choi, Byung-Ok

    2016-01-01

    The Charcot-Marie-Tooth disease 2F (CMT2F) and distal hereditary motor neuropathy 2B (dHMN2B) are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1) gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs) of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.

  7. HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation

    Directory of Open Access Journals (Sweden)

    Ji-Yon Kim

    2016-01-01

    Full Text Available The Charcot-Marie-Tooth disease 2F (CMT2F and distal hereditary motor neuropathy 2B (dHMN2B are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1 gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.

  8. Recommendations to enable drug development for inherited neuropathies: Charcot-Marie-Tooth and Giant Axonal Neuropathy [v1; ref status: indexed, http://f1000r.es/33n

    Directory of Open Access Journals (Sweden)

    Lori Sames

    2014-04-01

    Full Text Available Approximately 1 in 2500 Americans suffer from Charcot-Marie-Tooth (CMT disease. The underlying disease mechanisms are unique in most forms of CMT, with many point mutations on various genes causing a toxic accumulation of misfolded proteins. Symptoms of the disease often present within the first two decades of life, with CMT1A patients having reduced compound muscle and sensory action potentials, slow nerve conduction velocities, sensory loss, progressive distal weakness, foot and hand deformities, decreased reflexes, bilateral foot drop and about 5% become wheelchair bound. In contrast, the ultra-rare disease Giant Axonal Neuropathy (GAN is frequently described as a recessively inherited condition that results in progressive nerve death. GAN usually appears in early childhood and progresses slowly as neuronal injury becomes more severe and leads to death in the second or third decade. There are currently no treatments for any of the forms of CMTs or GAN. We suggest that further clinical studies should analyse electrical impedance myography as an outcome measure for CMT. Further, additional quality of life (QoL assessments for these CMTs are required, and we need to identify GAN biomarkers as well as develop new genetic testing panels for both diseases. We propose that using the Global Registry of Inherited Neuropathy (GRIN could be useful for many of these studies. Patient advocacy groups and professional organizations (such as the Hereditary Neuropathy Foundation (HNF, Hannah's Hope Fund (HHF, The Neuropathy Association (TNA and the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM can play a central role in educating clinicians and patients. Undertaking these studies will assist in the correct diagnosis of disease recruiting patients for clinical studies, and will ultimately improve the endpoints for clinical trials. By addressing obstacles that prevent industry investment in various forms of inherited neuropathies

  9. Recommendations to enable drug development for inherited neuropathies: Charcot-Marie-Tooth and Giant Axonal Neuropathy [v2; ref status: indexed, http://f1000r.es/3am

    Directory of Open Access Journals (Sweden)

    Lori Sames

    2014-04-01

    Full Text Available Approximately 1 in 2500 Americans suffer from Charcot-Marie-Tooth (CMT disease. The underlying disease mechanisms are unique in most forms of CMT, with many point mutations on various genes causing a toxic accumulation of misfolded proteins. Symptoms of the disease often present within the first two decades of life, with CMT1A patients having reduced compound muscle and sensory action potentials, slow nerve conduction velocities, sensory loss, progressive distal weakness, foot and hand deformities, decreased reflexes, bilateral foot drop and about 5% become wheelchair bound. In contrast, the ultra-rare disease Giant Axonal Neuropathy (GAN is frequently described as a recessively inherited condition that results in progressive nerve death. GAN usually appears in early childhood and progresses slowly as neuronal injury becomes more severe and leads to death in the second or third decade. There are currently no treatments for any of the forms of CMTs or GAN. We suggest that further clinical studies should analyse electrical impedance myography as an outcome measure for CMT. Further, additional quality of life (QoL assessments for these CMTs are required, and we need to identify GAN biomarkers as well as develop new genetic testing panels for both diseases. We propose that using the Global Registry of Inherited Neuropathy (GRIN could be useful for many of these studies. Patient advocacy groups and professional organizations (such as the Hereditary Neuropathy Foundation (HNF, Hannah's Hope Fund (HHF, The Neuropathy Association (TNA and the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM can play a central role in educating clinicians and patients. Undertaking these studies will assist in the correct diagnosis of disease recruiting patients for clinical studies, and will ultimately improve the endpoints for clinical trials. By addressing obstacles that prevent industry investment in various forms of inherited neuropathies

  10. Two different pathogenic mechanisms, dying-back axonal neuropathy and pancreatic senescence, are present in the YG8R mouse model of Friedreich’s ataxia

    Directory of Open Access Journals (Sweden)

    Belén Mollá

    2016-06-01

    Full Text Available Frataxin (FXN deficiency causes Friedreich’s ataxia (FRDA, a multisystem disorder with neurological and non-neurological symptoms. FRDA pathophysiology combines developmental and degenerative processes of dorsal root ganglia (DRG, sensory nerves, dorsal columns and other central nervous structures. A dying-back mechanism has been proposed to explain the peripheral neuropathy and neuropathology. In addition, affected individuals have non-neuronal symptoms such as diabetes mellitus or glucose intolerance. To go further in the understanding of the pathogenic mechanisms of neuropathy and diabetes associated with the disease, we have investigated the humanized mouse YG8R model of FRDA. By biochemical and histopathological studies, we observed abnormal changes involving muscle spindles, dorsal root axons and DRG neurons, but normal findings in the posterior columns and brain, which agree with the existence of a dying-back process similar to that described in individuals with FRDA. In YG8R mice, we observed a large number of degenerated axons surrounded by a sheath exhibiting enlarged adaxonal compartments or by a thin disrupted myelin sheath. Thus, both axonal damage and defects in Schwann cells might underlie the nerve pathology. In the pancreas, we found a high proportion of senescent islets of Langerhans in YG8R mice, which decreases the β-cell number and islet mass to pathological levels, being unable to maintain normoglycemia. As a whole, these results confirm that the lack of FXN induces different pathogenic mechanisms in the nervous system and pancreas in the mouse model of FRDA: dying back of the sensory nerves, and pancreatic senescence.

  11. Research progress of acute motor axonal neuropathy%急性运动轴索性神经病的研究进展

    Institute of Scientific and Technical Information of China (English)

    张刚; 秦新月

    2014-01-01

    急性运动轴索性神经病(AMAN)是吉兰-巴雷综合征(GBS)的主要亚型之一,与GBS主要亚型急性炎症性脱髓鞘性多发性神经病(AIDP)在临床表现、免疫病理生理机制、神经电生理检查、血清学抗体等方面均有不同。本文就AMAN相关研究进展做一综述。%Acute motor axonal neuropathy (AMAN) is one of the main subtypes of Guillain-Barré syndrome (GBS), which presents with acute ascending flaccid paralysis like acute inflammatory demyelinating polyneuropathy (AIDP). But AMAN can be different with AIDP in clinical manifestation, immunopathogenesis, electrophysiology, serum antibody, prognosis, et al. This review focused on the research progress of AMAN.

  12. Mitochondrial dynamics and peripheral neuropathy.

    Science.gov (United States)

    Baloh, Robert H

    2008-02-01

    Peripheral neuropathy is perhaps the archetypal disease of axonal degeneration, characteristically involving degeneration of the longest axons in the body. Evidence from both inherited and acquired forms of peripheral neuropathy strongly supports that the primary pathology is in the axons themselves and points to disruption of axonal transport as an important disease mechanism. Recent studies in human genetics have further identified abnormalities in mitochondrial dynamics--the fusion, fission, and movement of mitochondria--as a player in the pathogenesis of inherited peripheral neuropathy. This review provides an update on the mechanisms of mitochondrial trafficking in axons and the emerging relationship between the disruption of mitochondrial dynamics and axonal degeneration. Evidence suggests mitochondria are a "critical cargo" whose transport is necessary for proper axonal and synaptic function. Importantly, understanding the regulation of mitochondrial movement and the consequences of decreased axonal mitochondrial function may define new paths for therapeutic agents in peripheral neuropathy and other neurodegenerative diseases.

  13. Poor efficacy of the phosphorylated high-molecular-weight neurofilament heavy subunit serum level, a biomarker of axonal damage, as a marker of chemotherapy-induced peripheral neuropathy

    Science.gov (United States)

    SUMITANI, MASAHIKO; OGATA, TORU; NATORI, AKINA; HOZUMI, JUN; SHIMOJO, NOBUTAKE; KIDA, KUMIKO; YAMAUCHI, HIDEKO; YAMAUCHI, TERUO

    2016-01-01

    The phosphorylated form of the high-molecular-weight neurofilament heavy subunit (pNF-H) is a major structural protein in axons. The pNF-H level is elevated in the serum of certain patients with central nervous disorders, including chemotherapy-induced cognitive impairment. The present study was conducted to elucidate the potential role of pNF-H as a marker of chemotherapy-induced peripheral neuropathy (CIPN). A total of 71 patients with early breast cancer in various stages of treatment (following 1, 3 or 7 cycles of chemotherapy, or a previous history of breast cancer chemotherapy) were assessed with a self-administered PainDETECT questionnaire [pain location, pain intensity on an 11-point numeric rating scale (NRS), and various pain qualities] and a single serum pNF-H measurement. Patients were divided into two groups based on the presence or absence of bilateral symmetric pain in the distal portions of the extremities [CIPN(+) or CIPN(−)]. The χ2 and Mann-Whitney tests were used for statistical analyses. Among the participants, only 8 patients complained of CIPN. Their pain intensity was 3.5±1.9 (mean ± standard deviation) compared with 1.5±1.8 in the CIPN(−) group (P<0.01). The NRS of numbness in the CIPN(+) group was significantly higher (2.4±1.4) than that of the CIPN(−) group (1.0±1.0). Increased pNF-H levels were observed in 37.5% of the CIPN(+) patients and in 23.8% of CIPN(−) patients (P=0.40). In conclusion, CIPN is observed in the most distal portions of the peripheral nerves that are composed of dendrites but not axons. Although serum pNF-H is a biomarker of axonal damage, it is not useful as a marker of CIPN. PMID:27284419

  14. Comparison of Nerve Excitability Testing, Nerve Conduction Velocity, and Behavioral Observations for Acrylamide Induced Peripheral Neuropathy

    Science.gov (United States)

    Nerve excitability (NE) testing is a sensitive method to test for peripheral neurotoxicity in humans,and may be more sensitive than compound nerve action potential (CNAP) or nerve conduction velocity (NCV).We used acrylamide to compare the NE and CNAP/NCV methods. Behavioral test...

  15. Comparison of Nerve Excitability Testing, Nerve Conduction Velocity, and Behavioral Observations for Acrylamide Induced Peripheral Neuropathy

    Science.gov (United States)

    Nerve excitability (NE) testing is a sensitive method to test for peripheral neurotoxicity in humans,and may be more sensitive than compound nerve action potential (CNAP) or nerve conduction velocity (NCV).We used acrylamide to compare the NE and CNAP/NCV methods. Behavioral test...

  16. Acrylamide induces locomotor defects and degeneration of dopamine neurons in Caenorhabditis elegans.

    Science.gov (United States)

    Li, Jia; Li, Dan; Yang, Yongsheng; Xu, Tiantian; Li, Ping; He, Defu

    2016-01-01

    Acrylamide can form in foods during the cooking process and cause multiple adverse effects. However, the neurotoxicity and mechanisms of acrylamide have not been fully elucidated. In Caenorhabditis elegans, we showed that 48 h exposure to 10-625 mg l(-1) acrylamide resulted in a significant decline in locomotor frequency of body bending, head thrashing and pharynx pumping. In addition, acrylamide exposure reduced crawling speeds and changed angles of body bending. It indicates that acrylamide induces locomotor defects, along with parkinsonian-like movement impairment, including bradykinesia and hypokinesia. Acrylamide also affected chemotaxis plasticity and reduced learning ability. Using transgenic nematodes, we found that acrylamide induced downexpression of P(dat-1) and led to the degeneration of dopaminergic neurons. Moreover, the enhanced expression of unc-54, encoding a subunit of α-synuclein was found. It illustrates that acrylamide is efficient in inducing crucial parkinsonian pathology, including dopaminergic damage and α-synuclein aggregation. These findings suggest the acrylamide-induced locomotor defects and neurotoxicity are associated with Parkinson's disease. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Protective property of mulberry digest against oxidative stress - A potential approach to ameliorate dietary acrylamide-induced cytotoxicity.

    Science.gov (United States)

    Zhang, Linxia; Xu, Yang; Li, Yuting; Bao, Tao; Gowd, Vemana; Chen, Wei

    2017-09-01

    The aim of this study was investigating the protective effect of mulberry digest (MBD) on acrylamide-induced oxidative stress. Composition analysis of MBD revealed that it contained six major phenolic compounds (quercetin-3-O-rutinoside, quercetin hexoside, quercetin rhamnosylhexoside hexoside, kaempferol rhamnosylhexoside, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside). After in vitro digestion, the contents of two anthocyanins were both decreased significantly, while the contents of four flavonoid glycosides were all increased. In addition, MBD was found to successfully suppress acrylamide-induced ROS overproduction, restore the mitochondrial membrane potential, and inhibit the mitochondrial membrane lipid peroxidation and glutathione depletion. More interestingly, the protective effect of MBD against acrylamide-induced oxidative damage was enhanced compared with mulberry fruits without digestion (MBE). Further study revealed that MBD enhanced the cell resistance capacity to acrylamide-induced oxidative stress, rather than its direct reaction with acrylamide. Overall, our results indicate that MBD provides a potent protection against acrylamide-induced oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Peripheral neuropathies.

    Science.gov (United States)

    Hanewinckel, R; Ikram, M A; Van Doorn, P A

    2016-01-01

    Peripheral neuropathies are diseases of the peripheral nervous system that can be divided into mononeuropathies, multifocal neuropathies, and polyneuropathies. Symptoms usually include numbness and paresthesia. These symptoms are often accompanied by weakness and can be painful. Polyneuropathies can be divided into axonal and demyelinating forms, which is important for diagnostic reasons. Most peripheral neuropathies develop over months or years, but some are rapidly progressive. Some patients only suffer from mild, unilateral, slowly progressive tingling in the fingers due to median nerve compression in the wrist (carpal tunnel syndrome), while other patients can be tetraplegic, with respiratory insufficiency within 1-2 days due to Guillain-Barré syndrome. Carpal tunnel syndrome, with a prevalence of 5% and incidence of 1-2 per 1000 person-years, is the most common mononeuropathy. Population-based data for chronic polyneuropathy are relatively scarce. Prevalence is estimated at 1% and increases to 7% in persons over 65 years of age. Incidence is approximately 1 per 1000 person-years. Immune-mediated polyneuropathies like Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are rare diseases, with an annual incidence of approximately 1-2 and 0.2-0.5 per 100 000 persons respectively. Most peripheral neuropathies are more prevalent in older adults and in men, except for carpal tunnel syndrome, which is more common in women. Diabetes is a common cause of peripheral neuropathy and is associated with both mono- and polyneuropathies. Among the group of chronic polyneuropathies, in about 20-25% no direct cause can be found. These are slowly progressive axonal polyneuropathies. © 2016 Elsevier B.V. All rights reserved.

  19. Electrodiagnosis of peripheral neuropathy.

    Science.gov (United States)

    Ross, Mark A

    2012-05-01

    Electrodiagnostic studies are an important component of the evaluation of patients with suspected peripheral nerve disorders. The pattern of findings and the features that are seen on the motor and sensory nerve conduction studies and needle electromyography can help to identify the type of neuropathy, define the underlying pathophysiology (axonal or demyelinating), and ultimately help to narrow the list of possible causes. This article reviews the electrodiagnostic approach to and interpretation of findings in patients with peripheral neuropathies.

  20. [Developments in hereditary neuropathies].

    Science.gov (United States)

    Dubourg, O

    2012-12-01

    Hereditary sensorimotor neuropathies, or Charcot-Marie-Tooth disease (CMT) comprise a group of diseases with heterogeneous clinical, electrophysiological and genetic expression. They are classified by the mode of inheritance (autosomal dominant, X-linked dominant, autosomal recessive) and their electrophysiological characteristics taking into account the speed of motor conduction of the median nerve (demyelinating, intermediary and axonal forms). Certain purely motor forms are called spinal CMT or hereditary distal motor neuropathy, or distal spinal amyotrophy. CMT involving an important sensorial component, trophic disorders, or signs of dysautonomia are included in the classification of hereditary sensory and autonomic neuropathies.

  1. Olive oil abrogates acrylamide induced nephrotoxicity by modulating biochemical and histological changes in rats.

    Science.gov (United States)

    Ghorbel, Imen; Elwej, Awatef; Fendri, Nesrine; Mnif, Héla; Jamoussi, Kamel; Boudawara, Tahia; Grati Kamoun, Naziha; Zeghal, Najiba

    2017-11-01

    Acrylamide (ACR) is one of the most important contaminants occurring in foods heated at high temperatures. The aim of this study is to investigate the protective efficacy of extra virgin olive oil (EVOO), a main component of the Mediterranean diet, against nephrotoxicity induced by ACR. Rats have received by gavage during 21 days either ACR (40 mg/kg body weight) or ACR-associated with EVOO (300 μl) or only EVOO (300 μl). Acrylamide induced nephrotoxicity as evidenced by an increase in malondialdehyde (MDA), hydrogen peroxide (H2O2), protein carbonyls (PCOs) and a decrease in glutathione, non-protein thiols (NPSHs), and vitamin C levels. Activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) were also decreased. Lactate dehydrogenase (LDH) activity, creatinine, urea, and uric acid, urinary volume and creatinine clearance levels were modified. EVOO supplementation improved all the parameters indicated above. Kidney histoarchitecture confirmed the biochemical parameters and the beneficial role of EVOO. EVOO, when added to the diet, may have a beneficial role against kidney injury by scavenging free radicals and by its potent antioxidant power.

  2. Curcumin and (-)-epigallocatechin-3-gallate attenuate acrylamide-induced proliferation in HepG2 cells.

    Science.gov (United States)

    Shan, Xiaoyun; Li, Yuan; Meng, Xulian; Wang, Pengqi; Jiang, Pan; Feng, Qing

    2014-04-01

    Acrylamide, a proven rodent carcinogen, is present in carbohydrate-rich food heated at high temperatures. It can be metabolized into glycidamide mainly by cytochrome P450 2E1 (CYP2E1). The fact that acrylamide is a potential carcinogen to human-beings draws public attention recently. This study aimed to elucidate the effect of acrylamide at low doses on proliferation of HepG2 cells, and to test whether the two well-studied chemopreventive agents, curcumin and (-)-epigallocatechin-3-gallate (EGCG), would have antagonistic effects against acrylamide. The results showed that lower concentration of acrylamide (⩽100μM) significantly increased the proliferation of HepG2 cells, but not of the other cancer cells (MDA-231, HeLa, A549, and PC-3). Only in HepG2 cells, low concentration of acrylamide was able to induce CYP2E1 expression significantly. Knockdown of CYP2E1 restrained acrylamide to increase viability of HepG2 cells. In addition, acrylamide raised expression of epidermal growth factor receptor (EGFR), cyclin D1 and nuclear factor-κB (NF-κB), which contributed to cell proliferation. Both curcumin and EGCG effectively reduced acrylamide-induced proliferation, as well as protein expression of CYP2E1, EGFR, cyclin D1 and NF-κB. All these results suggest that low concentration of acrylamide may contribute to progression of hepatocellular carcinoma (HCC). Curcumin or EGCG could prevent acrylamide triggering this effect.

  3. De novo mutations in the motor domain of KIF1A cause cognitive impairment, spastic paraparesis, axonal neuropathy, and cerebellar atrophy

    NARCIS (Netherlands)

    Lee, Jae Ran; Srour, Myriam; Kim, Doyoun; Hamdan, Fadi F.; Lim, So Hee; Brunel-Guitton, Catherine; Décarie, Jean Claude; Rossignol, Elsa; Mitchell, Grant A.; Schreiber, Allison; Moran, Rocio; Van Haren, Keith; Richardson, Randal; Nicolai, Joost; Oberndorff, Karin M E J; Wagner, Justin D.; Boycott, Kym M.; Rahikkala, Elisa; Junna, Nella; Tyynismaa, Henna; Cuppen, Inge; Verbeek, Nienke E.; Stumpel, Connie T R M; Willemsen, Michel A.; de Munnik, Sonja A.; Rouleau, Guy A.; Kim, Eunjoon; Kamsteeg, Erik Jan; Kleefstra, Tjitske; Michaud, Jacques L.

    2015-01-01

    KIF1A is a neuron-specific motor protein that plays important roles in cargo transport along neurites. Recessive mutations in KIF1A were previously described in families with spastic paraparesis or sensory and autonomic neuropathy type-2. Here, we report 11 heterozygous de novo missense mutations (p

  4. Thalidomide neuropathy in childhood.

    Science.gov (United States)

    Fleming, Fiona J; Vytopil, Michal; Chaitow, Jeffrey; Jones, H Royden; Darras, Basil T; Ryan, Monique M

    2005-02-01

    Thalidomide was withdrawn from world markets in 1961 following recognition of its teratogenic effects. More recently, however, thalidomide treatment has been reintroduced to adult and paediatric practice for a variety of dermatologic, immunologic, rheumatologic and neoplastic disorders. Neuropathy is a significant side effect of thalidomide therapy, which may limit its clinical use. We report four cases of sensorimotor axonal neuropathy in children aged 10-15 years, treated with thalidomide for myxopapillary ependymoma, Crohn's disease and recurrent giant aphthous ulceration. Thalidomide neuropathy is often associated with proximal weakness and may progress even after discontinuation of treatment, in the phenomenon of 'coasting'. Children treated with thalidomide should undergo regular neurophysiologic studies in order to detect presymptomatic or progressive peripheral neuropathy.

  5. [Diabetic neuropathy].

    Science.gov (United States)

    Lechleitner, Monika; Abrahamian, Heidemarie; Francesconi, Claudia; Kofler, Markus

    2016-04-01

    These are the guidelines for diagnosis and treatment of diabetic neuropathy. This diabetic late complication comprises a number of mono- and polyneuropathies, plexopathies, radiculopathies and autonomic neuropathy. The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensorimotor neuropathy, are provided.

  6. Peripheral Neuropathy

    Science.gov (United States)

    ... neuropathy are caused by inborn mistakes in the genetic code or by new genetic mutations. × Definition Peripheral neuropathy ... neuropathy are caused by inborn mistakes in the genetic code or by new genetic mutations. View Full Definition ...

  7. Metabolic neuropathies

    Science.gov (United States)

    Neuropathy - metabolic ... can be caused by many different things. Metabolic neuropathy may be caused by: A problem with the ... one of the most common causes of metabolic neuropathies. People who are at the highest risk for ...

  8. Ocular neuropathy in peripheral neuropathies.

    Science.gov (United States)

    Evliyaoglu, Ferhat; Karadag, Remzi; Burakgazi, Ahmet Z

    2012-11-01

    Ocular movements and coordination require complex and integrated functions of somatic and autonomic nervous systems. Neurological disorders affecting these nervous systems may cause ocular dysfunction involving extraocular muscles and pupils. In this article, the prevalence, clinical presentations, and management of ocular neuropathy related to certain peripheral neuropathies, including diabetic neuropathy, Guillain-Barré syndrome (GBS), chronic inflammatory neuropathies, human immunodeficiency virus (HIV)-associated neuropathy, and hereditary neuropathies, are examined in detail. Copyright © 2012 Wiley Periodicals, Inc.

  9. Restoration of optic neuropathy

    Directory of Open Access Journals (Sweden)

    You SW

    2017-03-01

    Full Text Available Si-Wei You,1 Ming-Mei Wu,2 Fang Kuang,2 Kin-Sang Cho,3 Kwok-Fai So4,5 1Department of Ophthalmology, Xijing Hospital, 2Institute of Neurosciences, The Fourth Military Medical University, Xi’an, China; 3Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; 4GHM Institute of CNS Regeneration, Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, 5Department of Ophthalmology, The State Key laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong SAR, China Abstract: Optic neuropathy refers to disorders involving the optic nerve (ON. Any damage to ON or ON-deriving neurons, the retinal ganglion cells (RGCs, may lead to the breakdown of the optical signal transmission from the eye to the brain, thus resulting in a partial or complete vision loss. The causes of optic neuropathy include trauma, ischemia, inflammation, compression, infiltration, and mitochondrial damages. ON injuries include primary and secondary injuries. During these injury phases, various factors orchestrate injured axons to die back and become unable to regenerate, and these factors could be divided into two categories: extrinsic and intrinsic. Extrinsic inhibitory factors refer to the environmental conditions that influence the regeneration of injured axons. The presence of myelin inhibitors and glial scar, lack of neurotrophic factors, and inflammation mediated by injury are regarded as these extrinsic factors. Extrinsic factors need to trigger the intracellular signals to exert inhibitory effect. Proper regulation of these intracellular signals has been shown to be beneficial to ON regeneration. Intrinsic factors of RGCs are the pivotal reasons that inhibit ON regeneration and are closely linked with extrinsic factors. Intracellular cyclic adenosine monophosphate (cAMP and calcium levels affect axon guidance and growth cone response to guidance molecules

  10. Diabetic neuropathy part 1: overview and symmetric phenotypes.

    Science.gov (United States)

    Pasnoor, Mamatha; Dimachkie, Mazen M; Kluding, Patricia; Barohn, Richard J

    2013-05-01

    Diabetes is the most common cause of neuropathy in United States and neuropathies are the most common complication of diabetes mellitus, affecting up to 50% of patients with type 1 and type 2 diabetes mellitus. Symptoms usually include numbness, tingling, pain, and weakness. Dizziness with postural changes can be seen with autonomic neuropathy. Metabolic, vascular, and immune theories have been proposed for the pathogenesis of diabetic neuropathy. Axonal damage and segmental demyelination can be seen with diabetic neuropathies. Management of diabetic neuropathy should begin at the initial diagnosis of diabetes and mainly requires tight and stable glycemic control.

  11. [Hereditary peripheral neuropathies].

    Science.gov (United States)

    Vallat, Jean-Michel; Tazir, Mériem; Calvo, Judith; Funalot, Benoît

    2009-09-01

    Currently more than 30 genes are known to be responsible for genetically determined neuropathies. Charcot-Marie-Tooth (CMT) disease is the most frequent of these hereditary neuropathies, with a prevalence of 4.7 to 36 per 100 000. In its demyelinating forms (CMT1), approximately 70% of cases are associated with a duplication of the PMP22gene. In its axonal forms (CMT2), 10-20% of the cases may be associated with a mutation of the MFN2gene. For North African patients with recessive transmission, a mutation of the LMNA gene must be sought. It is essential to stress the great variability of the phenotype--clinical, electrophysiological, and histologic--between and within families. A detailed analysis of these criteria, together with consideration of ethnic origin, may guide the search for the causal mutation. Whether the case involves certainly hereditary transmission or a sporadic form, it is desirable to be able to examine the maximum number of the patient's kin, both clinically and electrophysiologically. The forms with recessive transmission usually have a very early onset and are more serious than the dominant forms. The early- and very early-onset forms of CMT are increasingly better distinguished: congenital hypomyelination neuropathy (mutations of PMP22, MPZ or EGR2), or more axonal forms, including SMARD1 (Spinal muscle atrophy with respiratory distress; mutations of IGHMBP2) and EOHMSN (Early-onset hereditary motor and sensory neuropathy; mutations of MFN2). The prevention of cutaneous (ulcerations), bone, and amputation complications is very important in patients with hereditary sensory and autonomic neuropathies, because of the severity of the sensory disorders.

  12. Peripheral Neuropathy

    Science.gov (United States)

    ... can be associated with peripheral neuropathy. Metabolic and endocrine disorders impair the body’s ability to transform nutrients into ... to neuropathies as a result of chemical imbalances. Endocrine disorders that lead to hormonal imbalances can disturb normal ...

  13. 27. Molecular spectra of acrylamide-induced mutation at hprt locus in human promyelocytic leukemia HL-60 and NB4. cell lines

    Institute of Scientific and Technical Information of China (English)

    刘胜学; 曹佳; 杨梦苏; 方志俊; 安辉

    2001-01-01

    The genotoxicity of acrylamide was investigated by methods of single cell clone culturing, two-way screening count, multiplex PCR amplification and electrophoresis technique. Acrylamide only showed clear mutagenesis until dose raised 700 mg*L-1 in HL-60 cells. The most frequent spontaneous mutation were point mutation (≥90.0%) and acrylamide-induced mutation mainly included partial deletion and point mutation (respectively 40.0%~66.7%/33.3%~60.0%). Total gene deletion wasn't discovered in both of cells. There were deletion mutation in all exons of hprt gene(except 7/8 exon), and toward the 3' end of the hprt gene. The most frequent acrylamide-induced mutation were point mutation and single exon deletion (93.3%/86.1%). There were not clear difference in both of cells. The results suggest that the spectra of spontaneous and acrylamide-induced mutants were different. and the smaller changes in genetic structure have something to do with mechanism.

  14. Diagnostic approach to peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Misra Usha

    2008-01-01

    Full Text Available Peripheral neuropathy refers to disorders of the peripheral nervous system. They have numerous causes and diverse presentations; hence, a systematic and logical approach is needed for cost-effective diagnosis, especially of treatable neuropathies. A detailed history of symptoms, family and occupational history should be obtained. General and systemic examinations provide valuable clues. Neurological examinations investigating sensory, motor and autonomic signs help to define the topography and nature of neuropathy. Large fiber neuropathy manifests with the loss of joint position and vibration sense and sensory ataxia, whereas small fiber neuropathy manifests with the impairment of pain, temperature and autonomic functions. Electrodiagnostic (EDx tests include sensory, motor nerve conduction, F response, H reflex and needle electromyography (EMG. EDx helps in documenting the extent of sensory motor deficits, categorizing demyelinating (prolonged terminal latency, slowing of nerve conduction velocity, dispersion and conduction block and axonal (marginal slowing of nerve conduction and small compound muscle or sensory action potential and dennervation on EMG. Uniform demyelinating features are suggestive of hereditary demyelination, whereas difference between nerves and segments of the same nerve favor acquired demyelination. Finally, neuropathy is classified into mononeuropathy commonly due to entrapment or trauma; mononeuropathy multiplex commonly due to leprosy and vasculitis; and polyneuropathy due to systemic, metabolic or toxic etiology. Laboratory investigations are carried out as indicated and specialized tests such as biochemical, immunological, genetic studies, cerebrospinal fluid (CSF examination and nerve biopsy are carried out in selected patients. Approximately 20% patients with neuropathy remain undiagnosed but the prognosis is not bad in them.

  15. [Autonomic peripheral neuropathy].

    Science.gov (United States)

    Adams, David; Cauquil, Cecile; Lozeron, Pierre

    2012-11-01

    The mechanisms of dysautonomic disturbances are varied and mostly acquired. They can result from lesions of sympathetic or parasympathetic vegetative fibers located in the peripheral contingent, or in the somatic contingent by demyelination or axonal loss; or more rarely by cellular bodies in the sympathetic or parasympathetic ganglia. Several chronic peripheral neuropathies can be associated with dysautonomia. Only some causes need to be known because they can be clinically significant. Dysautonomia may be seen during chronic acquired neuropathies but also acute or subacute ones. The most frequent cause in the world is the dysautonomia of the diabetes; it affects all the systems; the cardiovascular dysfunction has an impact on the prognosis for survival when it is severe. Hereditary autonomic neuropathies are rare; they can declare themselves very early during the Riley-Day syndrome or very late during amyloid polyneuropathies due to transthyretin gene mutation. The diagnosis can be confirmed by molecular biology. The dysautonomia is frequent and often severe. These neuropathies justify symptomatic treatment to improve quality of life. For some of them, a specific treatment can be proposed to treat the causal affection to try to stop the progression of the disease.

  16. Vasculitic peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Mona Amini

    2014-02-01

    Full Text Available Primary systemic vasculitis in pre-capillary arteries is associated with peripheral neuropathy. In some types of systematic vasculitis about 60 % of patients have peripheral nervous system (PNS involvement. In vasculitic peripheral neuropathies (VPN a necrotizing and inflammatory process leads to narrowing of vasa nervorum lumen and eventually the appearance of ischemic lesions in peripheral nerves. Some features might be suggestive of VPN, like: axonal nerve degeneration, wallerian-like degeneration, and diameter irregularity of nerve. Peripheral nervous system (PNS destruction during systemic vasculitides should be considered, due to its frequency and early occurrence in vasculitis progression. The first line treatment of non systematic VPNs is corticosteroid agents, but these drugs might worsen the VPNs or systemic vasculitis.

  17. Trigonella foenum-graecum ameliorates acrylamide-induced toxicity in rats: Roles of oxidative stress, proinflammatory cytokines, and DNA damage.

    Science.gov (United States)

    Abdel-Daim, Mohamed M; Abd Eldaim, Mabrouk A; Hassan, Abeer G A

    2015-06-01

    Acrylamide is a hazardous substance inducing oxidative stress. Based on some evidence on the antioxidant properties of fenugreek, Trigonella foenum-graecum, this study was conducted to investigate the protective effect of fenugreek seed oil against acrylamide toxicity. Thirty-two male Wistar rats were randomly assigned into four groups. The control group was given normal saline. The second group was administered acrylamide (20 mg/kg bw orally). The third and fourth groups were administered acrylamide (20 mg/kg bw) and supplemented with 2.5% and 5% fenugreek seed oil in their diets, respectively. Acrylamide intoxication significantly increased serum levels of LDH, AST, ALT, APL, γ-GT, cholesterol, uric acid, urea, creatinine, 8-oxo-2'-deoxyguanosine, interleukin 1 beta, interleukin 6, and tumor necrosis factor α. Moreover, it increased hepatic, renal, and brain lipid peroxidation, while it impaired the activities and concentrations of the antioxidant biomarkers. Fenugreek oil supplementation normalized the altered serum parameters, prevented lipid peroxidation, and enhanced the antioxidant biomarker concentrations and activities in the hepatic, renal, and brain tissues of acrylamide-intoxicated rats in a dose-dependent manner. Thus, these results indicate that Trigonella foenum-graecum oil has a protective effect against acrylamide-induced toxicity through its free radical scavenging and potent antioxidant activities.

  18. Purple pigments: the pathophysiology of acute porphyric neuropathy.

    Science.gov (United States)

    Lin, Cindy S-Y; Lee, Ming-Jen; Park, Susanna B; Kiernan, Matthew C

    2011-12-01

    The porphyrias are inherited metabolic disorders arising from disturbance in the haem biosynthesis pathway. The neuropathy associated with acute intermittent porphyria (AIP) occurs due to mutation involving the enzyme porphobilinogen deaminase (PBGD) and is characterised by motor-predominant features. Definitive diagnosis often encompasses a combination of biochemical, enzyme analysis and genetic testing, with clinical neurophysiological findings of a predominantly motor axonal neuropathy. Symptomatic and supportive treatment are the mainstays during an acute attack. If administered early, intravenous haemin may prevent progression of neuropathy. While the pathophysiology of AIP neuropathy remains unclear, axonal dysfunction appears intrinsically linked to the effects of neural energy deficits acquired through haem deficiency coupled to the neurotoxic effects of porphyrin precursors. The present review will provide an overview of AIP neuropathy, including discussion of recent advances in understanding developed through neurophysiological approaches that have further delineated the pathophysiology of axonal degeneration.

  19. Ultrasound of the peripheral nerves in systemic vasculitic neuropathies.

    Science.gov (United States)

    Grimm, Alexander; Décard, Bernhard F; Bischof, Antje; Axer, Hubertus

    2014-12-15

    Ultrasound of the peripheral nerves (PNUS) can be used to visualize nerve pathologies in polyneuropathies (PNP). The aim of this study was to investigate, whether PNUS provides additional information in patients with proven systemic vasculitic neuropathies (VN). Systematic ultrasound measurements of several peripheral nerves, the vagal nerve and the 6th cervical nerve root were performed in 14 patients and 22 healthy controls. Nerve conduction studies of the corresponding nerves were undertaken. Finally, the measured results were compared to a study population of demyelinating immune-mediated and axonal neuropathies. Patients with VN displayed significant smaller amplitudes of compound muscle action potentials (CMAP) (pneuropathies than in other axonal neuropathies, but significantly rarer than in demyelinating neuropathies. Focal CSA enlargement in one or more nerves in electrophysiologically axonal neuropathies can be a hint for VN and thus facilitate diagnostic and therapeutic procedures. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Inflammatory neuropathies.

    Science.gov (United States)

    Whitesell, Jackie

    2010-09-01

    Inflammatory neuropathies are acquired disorders of peripheral nerves and occasionally of the central nervous system that can affect individuals at any age. The course can be monophasic, relapsing, or progressive. Inflammatory neuropathies are classified as acute or chronic. The acute form reaches a nadir by 4 weeks and the chronic form over 8 weeks or greater. The most common example of an acute inflammatory neuropathy is acute inflammatory demyelinating polyradiculoneuropathy (AIDP), which is part of the Guillain-Barré syndrome (GBS). The most common chronic inflammatory neuropathy is chronic inflammatory demyelinating polyradiculopathy (CIDP). Other chronic inflammatory neuropathies are multifocal motor neuropathy (MMN) and the Lewis-Sumner syndrome. The Fisher syndrome and Bickerstaff brainstem encephalitis occur acutely and have clinical overlap with AIDP.

  1. Autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1980-01-01

    In order to elucidate the physiological significance of autonomic neuropathy in juvenile diabetics, cardiovascular, hormonal and metabolic functions have been investigated in three groups of juvenile diabetics: One group had no signs of neuropathy, one group had presumably slight autonomic...... neuropathy (reduced beat-to-beat variation in heart rate during hyperventilation) and one group had clinically severe autonomic neuropathy, defined by presence of orthostatic hypotension. In all three experimental situations we found sympathetic dysfunction causing cardiovascular and/or hormonal...... maladjustments in patients with autonomic neuropathy. Regarding metabolic functions we found normal responses to graded exercise and insulin-induced hypoglycemia in patients with autonomic neuropathy in spite of blunted catecholamine responses, suggesting increased sensitivity of glycogen stores and adipose...

  2. Sensory correlates of pain in peripheral neuropathies.

    Science.gov (United States)

    Ng Wing Tin, Sophie; Ciampi de Andrade, Daniel; Goujon, Colette; Planté-Bordeneuve, Violaine; Créange, Alain; Lefaucheur, Jean-Pascal

    2014-05-01

    To characterize sensory threshold alterations in peripheral neuropathies and the relationship between these alterations and the presence of pain. Seventy-four patients with length-dependent sensory axonal neuropathy were enrolled, including 38 patients with painful neuropathy (complaining of chronic, spontaneous neuropathic pain in the feet) and 36 patients with painless neuropathy. They were compared to 28 age-matched normal controls. A standardized quantitative sensory testing protocol was performed in all individuals to assess large and small fiber function at the foot. Large fibers were assessed by measuring mechanical (pressure and vibration) detection thresholds and small fibers by measuring pain and thermal detection thresholds. Between patients with neuropathy and controls, significant differences were found for mechanical and thermal detection thresholds but not for pain thresholds. Patients with painful neuropathy and those with painless neuropathy did not differ regarding mechanical or thermal thresholds, but only by a higher incidence of thermal or dynamic mechanical allodynia in case of painful neuropathy. Pain intensity correlated with the alteration of thermal detection and mechanical pain thresholds. Quantitative sensory testing can support the diagnosis of sensory neuropathy when considering detection threshold measurement. Thermal threshold deterioration was not associated with the occurrence of pain but with its intensity. There is a complex relationship between the loss or functional deficit of large and especially small sensory nerve fibers and the development of pain in peripheral neuropathy. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Amyloid neuropathies.

    Science.gov (United States)

    Shin, Susan C; Robinson-Papp, Jessica

    2012-01-01

    Peripheral neuropathy is a common complication of many of the systemic amyloidoses. Although the cause of neuropathy is not entirely clear, it is likely related to amyloid deposition within the nerve. This may lead to focal, multifocal, or diffuse neuropathies involving sensory, motor and/or autonomic fibers. The presenting symptoms depend on the distribution of nerves affected. One of the most common phenotypes is sensorimotor polyneuropathy, which is characterized by symptoms of neuropathic pain, numbness, and in advanced cases weakness. Symptoms begin in the feet and ultimately progress to the proximal legs and hands. The most common focal neuropathy is a median neuropathy at the wrist, clinically known as carpal tunnel syndrome. Carpal tunnel symptoms may include pain and sensory disturbances in the lateral palm and fingers; hand weakness may ensue if the focal neuropathy is severe. Autonomic neuropathy may affect a variety of organ systems such as the cardiovascular, gastrointestinal, and genitourinary systems. Symptoms may be non-specific making the diagnosis of autonomic neuropathy more difficult to identify. However, it is important to recognize and distinguish autonomic neuropathy from diseases of the end-organs themselves. This article reviews the inherited and acquired amyloidoses that affect the peripheral nervous system including familial amyloid polyneuropathy, and primary, secondary and senile amyloidosis. We emphasize the clinical presentation of the neurologic aspects of these diseases, physical examination findings, appropriate diagnostic evaluation, treatment and prognosis. © 2012 Mount Sinai School of Medicine.

  4. [Autonomic neuropathies].

    Science.gov (United States)

    Siepmann, T; Penzlin, A I; Illigens, B M W

    2013-07-01

    Autonomic neuropathies are a heterogeneous group of diseases that involve damage of small peripheral autonomic Aδ- and C-fibers. Causes of autonomic nerve fiber damage are disorders such as diabetes mellitus and HIV-infection. Predominant symptoms of autonomic neuropathy are orthostatic hypotension, gastro-intestinal problems, urogenital dysfunction, and cardiac arrhythmia, which can severely impair the quality of life in affected patients. Furthermore, autonomic neuropathies can be induced by autoimmune diseases such as acute inflammatory demyelinating polyneuropathy, hereditary disorders such as the lysosomal storage disorder Fabry disease and hereditary sensory and autonomic neuropathies, as well as certain toxins and drugs.

  5. Genetics Home Reference: giant axonal neuropathy

    Science.gov (United States)

    ... Case Rep. 2014 Sep 12;2014. pii: bcr2014204481. doi: 10.1136/bcr-2014-204481. Citation on PubMed Mussche S, De Paepe B, Smet J, Devreese K, Lissens W, Rasic VM, Murnane M, Devreese B, Van Coster R. ... Citation on PubMed Neuromuscular ...

  6. Paraneoplastic neuropathies.

    Science.gov (United States)

    Antoine, Jean-Christophe; Camdessanché, Jean-Philippe

    2017-10-01

    To review recent advances in paraneoplastic neuropathies with emphasis on their definition, different forms and therapeutic development. A strict definition of definite paraneoplastic neuropathies is necessary to avoid confusion. With carcinoma, seronegative sensory neuronopathies and neuronopathies and anti-Hu and anti-CV2/Contactin Response Mediator Protein 5 antibodies are the most frequent. With lymphomas, most neuropathies occur with monoclonal gammopathy including AL amyloidosis, Polyneuropathy-Organomegaly-Endocrinopathy-M component-Skin changes (POEMS) syndrome, type I cryoglobulinemia and antimyelin-associated glycoprotein (MAG) neuropathies and Waldenström's disease. Neuropathies improving with tumor treatment are occasional, occur with a variety of cancer and include motor neuron disease, chronic inflammatory demyelinating neuropathy and nerve vasculitis. If antibodies toward intracellular antigens are well characterized, it is not the case for antibodies toward cell membrane proteins. Contactin-associated protein-2 antibodies occur with neuromyotonia and thymoma with the Morvan's syndrome in addition to Netrin 1 receptor antibodies but may not be responsible for peripheral nerve hyperexcitability. The treatment of AL amyloidosis, POEMS syndrome, anti-MAG neuropathy and cryoglobulinemia is now relatively well established. It is not the case with onconeural antibodies for which the rarity of the disorders and a short therapeutic window are limiting factors for the development of clinical trials. A strict definition of paraneoplastic neuropathies helps their identification and is necessary to allow an early diagnosis of the underlying tumor.

  7. [Diabetic neuropathy].

    Science.gov (United States)

    Chudzik, Wiesław; Kaczorowska, Beata; Przybyła, Monika; Chudzik, Bartosz; Gałka, Małgorzata

    2007-01-01

    Diabetic neuropathy is most common chronic complication of diabetes mellitus. It is responsible for substantial morbidity, increased mortality and impaired quality of life. Patogenesis of diabetic neuropathy is complex. Chronic hyperglycemia is a major factor induces nerve fibers injury. High level of glucose stimulate the polyol pathway causing osmotic stress and enhance reactive oxygen species generation, as well as it play an important role in diabetic angiopathy development. Distal symmetric polineuropathy is most common type of diabetic neuropathy. Many patient may develop combinations of neuropathies concerning somatic and autonomic system. Early diagnosis and administered suitable treatment are necessary to reduce severe complication of diabetic neuropathy as well as strict glycemic control and risk factor increased.

  8. [Hereditary neuropathies].

    Science.gov (United States)

    Vallat, Jean-Michel; Calvo, Judith; Ghorab, Karima; Tazir, Meriem

    2008-11-15

    Although there are many human hereditary neuropathies, most of them with the exception of Charcot-Marie-Tooth disease or hereditary sensorimotor neuropathy, are rare. Irrespective of their type, the mode of transmission may be autosomal dominant or recessive, or X-linked. The most difficult to diagnose, however, are the sporadic forms. It is customary to distinguish the cases in which the neuropathy is the sole clinical expression from multisystemic diseases where neuropathy is one component of multi-organ involvement. The complexity and the multiplicity of genes involved and the lack of understanding of their exact functions hinder logical presentation of these hereditary neuropathies. For understandable technical reasons, the stage of specific treatment, namely the repair of the mutated gene, has yet to be attained.

  9. Hereditary neuropathies: An update.

    Science.gov (United States)

    Stojkovic, T

    2016-12-01

    Hereditary neuropathies are the most common inherited neuromuscular diseases. Charcot-Marie-Tooth (CMT) disease represents the most common form with an average prevalence ranging from 1/2500 to 1/1200, depending on the studies. To date and with the advances of the latest generation sequencing, more than 80 genes have been identified. Although the common clinical phenotype comprises a progressive distal muscle weakness and sensory loss, foot deformities and decreased or absent tendon reflexes, clinical and electrophysiological phenotypes exhibit great variability. Moreover, atypical phenotypes are arising, overlapping with spastic paraplegia, hereditary sensory neuropathies or amyotrophic lateral sclerosis. The causative genes are involved in various biological processes such as myelin development and maintenance, biosynthesis and degradation of proteins, neuronal structural maintenance, axonal transport, endocytosis, membrane dynamics, ion-channel function and the mitochondrial network. An accurate genetic diagnosis is important for appropriate genetic counselling and treatment options. Therapeutic advances, particularly small interfering RNA therapy, are encouraging in hereditary transthyretin amyloid neuropathy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Neuropathy of nitroimidazole radiosensitizers: clinical and pathological description

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    Wasserman, T.H.; Nelson, J.S.; VonGerichten, D.

    1984-09-01

    The dose limiting toxicity of the nitroimidazole radiosensitizers is peripherial neuropathy. Improved pharmacology of newer drugs has eliminated the encephalopathy. Peripheral neuropathies are predominently mild to moderate paresthesias of both hands and feet. Subjective changes occur with or without minimal objective changes on neurologic exam. All of the neuropathies occurred within 30 days of the last drug dose and are of varible duration. Sural nerve biopsies from patients indicate progressive axonal degeneration affecting both large and small caliber myelinated fibers. Axonal damage appears to be more severe in the distal portion of the nerves. More data are needed for correlation of clinical and pathological changes.

  11. Peripheral neuropathy associated with mitochondrial disease in children.

    Science.gov (United States)

    Menezes, Manoj P; Ouvrier, Robert A

    2012-05-01

    Mitochondrial diseases in children are often associated with a peripheral neuropathy but the presence of the neuropathy is under-recognized because of the overwhelming involvement of the central nervous system (CNS). These mitochondrial neuropathies are heterogeneous in their clinical, neurophysiological, and histopathological characteristics. In this article, we provide a comprehensive review of childhood mitochondrial neuropathy. Early recognition of neuropathy may help with the identification of the mitochondrial syndrome. While it is not definite that the characteristics of the neuropathy would help in directing genetic testing without the requirement for invasive skin, muscle or liver biopsies, there appears to be some evidence for this hypothesis in Leigh syndrome, in which nuclear SURF1 mutations cause a demyelinating neuropathy and mitochondrial DNA MTATP6 mutations cause an axonal neuropathy. POLG1 mutations, especially when associated with late-onset phenotypes, appear to cause a predominantly sensory neuropathy with prominent ataxia. The identification of the peripheral neuropathy also helps to target genetic testing in the mitochondrial optic neuropathies. Although often subclinical, the peripheral neuropathy may occasionally be symptomatic and cause significant disability. Where it is symptomatic, recognition of the neuropathy will help the early institution of rehabilitative therapy. We therefore suggest that nerve conduction studies should be a part of the early evaluation of children with suspected mitochondrial disease.

  12. Autonomic neuropathies

    Science.gov (United States)

    Low, P. A.

    1998-01-01

    A limited autonomic neuropathy may underlie some unusual clinical syndromes, including the postural tachycardia syndrome, pseudo-obstruction syndrome, heat intolerance, and perhaps chronic fatigue syndrome. Antibodies to autonomic structures are common in diabetes, but their specificity is unknown. The presence of autonomic failure worsens prognosis in the diabetic state. Some autonomic neuropathies are treatable. Familial amyloid polyneuropathy may respond to liver transplantation. There are anecdotal reports of acute panautonomic neuropathy responding to intravenous gamma globulin. Orthostatic hypotension may respond to erythropoietin or midodrine.

  13. Peripheral Neuropathy in Rats Exposed to Dichloroacetate

    Science.gov (United States)

    Calcutt, Nigel A.; Lopez, Veronica L.; Bautista, Arjel D.; Mizisin, Leah M.; Torres, Brenda R.; Shroads, Albert L.; Mizisin, Andrew P.; Stacpoole, Peter W.

    2009-01-01

    The use of dichloroacetate (DCA) for treating patients with mitochondrial diseases is limited by the induction of peripheral neuropathy. The mechanisms of DCA-induced neuropathy are not known. Oral DCA treatment (50–500 mg/kg/day for up to 16 weeks) induced tactile allodynia in both juvenile and adult rats; concurrent thermal hypoalgesia developed at higher doses. Both juvenile and adult rats treated with DCA developed nerve conduction slowing that was more pronounced in adult rats. No overt axonal or glial cell abnormalities were identified in peripheral nerves or spinal cord of any DCA-treated rats but morphometric analysis identified a reduction of mean axonal caliber of peripheral nerve myelinated fibers. DCA treatment also caused accumulation of oxidative stress markers in the nerves. These data indicate that behavioral, functional and structural indices of peripheral neuropathy may be induced in both juvenile and adult rats treated with DCA at doses similar to those in clinical use. DCA-induced peripheral neuropathy primarily afflicts axons and involves both metabolic and structural disorders. The DCA-treated rat may provide insight into the pathogenesis of peripheral neuropathy and facilitate development of adjuvant therapeutics to prevent this disorder that currently restricts the clinical use of DCA. PMID:19680144

  14. Why Are Sensory Axons More Vulnerable for Ischemia than Motor Axons?

    NARCIS (Netherlands)

    Hofmeijer, Jeannette; Franssen, H.; van Schelven, L.J.; van Putten, Michel Johannes Antonius Maria

    2013-01-01

    Objective:In common peripheral neuropathies, sensory symptoms usually prevail over motor symptoms. This predominance of sensory symptoms may result from higher sensitivity of sensory axons to ischemia.Methods:We measured median nerve compound sensory action potentials (CSAPs), compound muscle action

  15. Vasculitic neuropathies.

    Science.gov (United States)

    Gwathmey, Kelly Graham; Burns, Ted Michael; Collins, Michael Paul; Dyck, P James Bonham

    2014-01-01

    The vasculitic neuropathies are a diverse group of disorders characterised by the acute-to-subacute onset of painful sensory and motor deficits that result from inflammatory destruction of nerve blood vessels and subsequent ischaemic injury. They are common in patients with primary systemic vasculitis and are seen in vasculitis secondary to disorders such as rheumatoid arthritis, viral infections, and diabetic inflammatory neuropathies. It is imperative that neurologists recognise these disorders to initiate treatment promptly and thereby prevent morbidity and mortality. To simplify the approach to patients with vasculitis of the peripheral nerves, a straightforward, dichotomous classification scheme can be used in which the vasculitic neuropathies are divided into two groups-nerve large arteriole vasculitis and nerve microvasculitis-on the basis of the size of the involved vessels. The size of the affected blood vessels correlates with the clinical course and prognosis in patients with vasculitic neuropathy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Autonomic Neuropathy

    Science.gov (United States)

    ... harm. Alpha-lipoic acid Preliminary research suggests this antioxidant may be helpful in slowing or even reversing ... electrical waves transmitted through electrodes placed on the skin, may help ease pain associated with diabetic neuropathy. ...

  17. Pyridoxine neuropathy.

    Science.gov (United States)

    Waterston, J A; Gilligan, B S

    1987-06-15

    A case of sensory neuropathy in a young woman due to long-term ingestion of pyridoxine, with subsequent recovery, is described. Pyridoxine neuropathy may occur after the long-term ingestion of doses as low as 200 mg a day. Because of its widespread use in the community, both the general public and the medical community need to be aware of this recently described complication of megavitamin therapy.

  18. L-cysteine, N-acetyl-L-cysteine, and glutathione protect Xenopus laevis embryos against acrylamide-induced malformations and mortality in the frog embryo teratogenesis assay.

    Science.gov (United States)

    Rayburn, James R; Friedman, Mendel

    2010-10-27

    Dietary acrylamide is largely derived from heat-induced reactions between the amino group of the free amino acid asparagine and carbonyl groups of glucose and fructose during heat processing (baking, frying) of plant-derived foods such as potato fries and cereals. After consumption, acrylamide is absorbed into the circulation and is then distributed to various organs, where it can react with DNA, neurons, hemoglobin, and essential enzymes. In the present study, we explored the potential of L-cysteine (CySH), N-acetyl-L-cysteine (NAC), reduced glutathione (GSH), and the amino acid glycine (Gly) to protect frog embryos against acrylamide-induced developmental toxicity in the frog embryo teratogenesis assay - Xenopus (FETAX). To test the antiteratogenic potential, based on concentration-response study ranging from 0.07 to 4.22 mM acrylamide in FETAX solution (pH 8.1), we selected concentrations of acrylamide that induced 100% malformations and mortality. At the end of 96 h, we counted survivors and malformed embryos and measured embryo length. The data show that CySH, NAC, and GSH protected the embryos against acrylamide induced malformations and mortality to different degrees. CySH and GSH protected the embryos against both malformations and mortality, whereas NAC protected only against mortality. Gly had no protective effect. Possible mechanisms of the protective effects and the dietary significance of the results of this and related studies for food safety and human health are discussed.

  19. [Chronic inflammatory demyelinating neuropathies and their variants

    Science.gov (United States)

    Vallat, J.-M.; Tabaraud, F.; Magy, L.; Macian, F.

    2002-12-01

    The Chronic Inflammatory Demyelinating Polyradiculoneuropathies (CIDP) constitute a syndrome whose incidence is difficult to evaluate, and is probably underestimated. In the course of this presentation, we deliberately restricted discussion to issues raised in recent years concerning the extent of this syndrome. We discuss diagnostic criteria, especially electrophysiological ones. As the criteria proposed by the ad hoc committee of the American Academy of Neurology in 1991 have been questioned due to lack of sensitivity, new ones have been proposed recently. We briefly discuss the different types of chronic dysimmune demyelinating neuropathy: not only the CIDP, but also the Lewis and Sumner syndrome or multifocal inflammatory demyelinating neuropathy and the multiple conduction block neuropathies. At last, we point out the consistent finding of axonal involvement in the course of a chronic demyelinating neuropathy; over time, it can become predominant, which may make diagnosis difficult by suggesting a chronic axonal neuropathy that may be assumed to be primary. Consideration of these points may help clinicians recognize more chronic dysimmune neuropathies, for which immunosuppressive therapy has been found to be effective.

  20. Acquired versus familial demyelinative neuropathies in children.

    Science.gov (United States)

    Miller, R G; Gutmann, L; Lewis, R A; Sumner, A J

    1985-01-01

    The electrophysiologic differences between chronic acquired demyelinative neuropathy and the demyelinative form of Charcot-Marie-Tooth disease have recently been reported. The present report extends these observations to include the genetically determined demyelinating neuropathies seen in metachromatic leukodystrophy, Krabbe's leukodystrophy, and Cockayne's syndrome. The electrophysiologic features of metachromatic leukodystrophy (five patients), Krabbe's (four patients), and Cockayne's syndrome (three patients) were all similar. There was uniform slowing of conduction (both in different nerves and in different nerve segments), and conduction block was not seen. These findings are consistent with a uniform degree of demyelination in multiple nerves and throughout the entire length of individual axons. Thus, uniform slowing of nerve conduction constitutes strong evidence for a familial demyelinative neuropathy, as opposed to the multifocal slowing seen in acute and chronic acquired demyelinative neuropathy.

  1. [Evidence-based Treatment for Vasculitic Neuropathies].

    Science.gov (United States)

    Koga, Michiaki

    2016-03-01

    Vasculitic neuropathies are caused by ischemic damage due to vessel wall inflammation. This damage may cause axonal degeneration leading to permanent neurological disabilities. Therefore, early initiation of effective treatment is crucial. For primary systemic vasculitis, a combined treatment of corticosteroid and immunosuppressive agents is recommended in the evidence-based guidelines as initial standard therapy for induction of remission. However, limited data are available regarding therapies for vasculitic neuropathies and it remains unclear whether combined treatment should be employed as an initial therapy for all patients with vasculitic neuropathies. In approximately half the patients with vasculitic neuropathies, monotherapy with corticosteroids is insufficient in preventing long-lasting neurological disabilities. Addition of intravenous immunoglobulin at an early stage of the disease may be a promising treatment option obviating the need for potent but potentially harmful immunosuppressive agents in some mild or localized cases.

  2. Diabetic Neuropathies.

    Science.gov (United States)

    Izenberg, Aaron; Perkins, Bruce A; Bril, Vera

    2015-08-01

    Diabetes mellitus is a common condition and diabetics are prone to develop a spectrum of neuropathic complications ranging from symmetric and diffuse to asymmetric and focal neuropathies that may be associated with significant morbidity. Diabetic sensorimotor polyneuropathy is the most common of these complications, occurring in patients with type 1 and 2 diabetes mellitus, as well as in those with prediabetes and glucose intolerance. In this review, the authors discuss the wide variety of neuropathies that can present in the context of diabetes, including the clinical manifestations, diagnostic features, and approach to management. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. Treatment of immune-mediated, dysimmune neuropathies.

    Science.gov (United States)

    Finsterer, J

    2005-08-01

    This review focuses on the actual status and recent advances in the treatment of immune-mediated neuropathies, including: Guillain-Barre syndrome (GBS) with its subtypes acute inflammatory demyelinating polyradiculoneuropathy, acute motor axonal neuropathy, acute motor and sensory axonal neuropathy, Miller Fisher syndrome, and acute pandysautonomia; chronic inflammatory demyelinating polyneuropathy (CIDP) with its subtypes classical CIDP, CIDP with diabetes, CIDP/monoclonal gammopathy of undetermined significance (MGUS), sensory CIDP, multifocal motor neuropathy (MMN), multifocal acquired demyelinating sensory and motor neuropathy or Lewis-Sumner syndrome, multifocal acquired sensory and motor neuropathy, and distal acquired demyelinating sensory neuropathy; IgM monoclonal gammopathies with its subtypes Waldenstrom's macroglobulinemia, myelin-associated glycoprotein-associated gammopathy, polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome, mixed cryoglobulinemia, gait ataxia, late-onset polyneuropathy syndrome, and MGUS. Concerning the treatment of GBS, there is no significant difference between intravenous immunoglobulins (IVIG), plasma exchange or plasma exchange followed by IVIG. Because of convenience and absent invasiveness, IVIG are usually preferred. In treating CIDP corticosteroids, IVIG, or plasma exchange are equally effective. Despite the high costs and relative lack of availability, IVIG are preferentially used. For the one-third of patients, who does not respond, other immunosuppressive options are available. In MMN IVIG are the treatment of choice. Inadequate response in 20% of the patients requires adjunctive immunosuppressive therapies. Neuropathies with IgM monoclonal gammopathy may respond to various chemotherapeutic agents, although the long-term effects are unknown. In addition, such treatment may be associated with serious side effects. Recent data support the use of rituximab, a monoclonal antibody against the B

  4. Peripheral neuropathy and antiretroviral drugs.

    Science.gov (United States)

    Dalakas, M C

    2001-03-01

    Patients treated with nucleoside analogue reverse transcriptase inhibitors (NRTIs) develop a varying degree of myopathy or neuropathy after long-term therapy. Zidovudine (AZT) causes myopathy; zalcitabine (ddC), didanosine (ddl) and lamuvidine (3TC) cause neuropathy; stavudine (d4T) and fialuridine (FIAU) cause neuropathy or myopathy and lactic acidosis. The tissue distribution of phosphorylases responsible for phosphorylation of NRTIs relates to their selective tissue toxicity. The myopathy is characterized by muscle wasting, myalgia, fatigue, weakness and elevation of CK. The neuropathy is painful, sensory and axonal. In vitro, NRTIs inhibit the gamma-DNA polymerase, responsible for replication of mtDNA, and cause mtDNA dysfunction. In vivo, patients treated with AZT, the best studied NRTI, develop a mitochondrial myopathy with mtDNA depletion, deficiency of COX (complex IV), intracellular fat accumulation, high lactate production and marked phosphocreatine depletion, as determined with in vivo MRS spectroscopy, due to impaired oxidative phosphorylation. Animals or cultured cells treated with NRTIs develop neuropathy, myopathy, or cell destruction with similar changes in the mitochondria. There is evidence that the NRTI-related neuropathy is also due to mitochondrial toxicity. The NRTIs (AZT, ddC, ddl, d4T, 3TC) contain azido groups that compete with natural thymidine triphosphate as substrates of DNA pol-gamma and terminate mtDNA synthesis. In contrast, FIAU that contains 3'-OH groups serves as an alternate substrate for thymidine triphosphate with DNA pol-gamma and is incorporated into the DNA causing permanent mtDNA dysfunction. The NRTI-induced mitochondrial dysfunction has an influence on the clinical application of these agents, especially at high doses and when combined. They have produced in humans a new category of acquired mitochondrial toxins that cause clinical manifestations resembling the genetic mitochondrial disorders.

  5. [Diagnosis of immune-mediated neuropathies].

    Science.gov (United States)

    Diószeghy, Péter

    2011-09-25

    Separate discussion of immune-mediated neuropathies from other neuropathies is justified by the serious consequences of the natural course of these diseases, like disability and sometimes even life threatening conditions. On the other hand nowadays effective treatments already exist, and with timely and correct diagnosis an appropriately chosen treatment may result in significant improvement of quality of life, occasionally even complete recovery. These are rare diseases, and the increasing number of different variants makes it more difficult to recognize them. Their diagnosis is based on the precise knowledge of clinical signs and symptoms, and it is verified by the help of neurophysiologic and laboratory, first of all CSF examinations. Description of clinical features of the classic acute immune-mediated neuropathy, characterized by ascending paresis and demyelination is followed by a summary of characteristics of newly recognized axonal, regional and functional variants. Chronic immune-mediated demyelinating polyneuropathies are not diagnosed in due number even today. This paper does not only present the classic form but it also introduces the ever increasing special variants, like distal acquired demyelinating sensory neuropathy, Lewis-Sumner syndrome, multifocal motor neuropathy and paraproteinemic neuropathies. Vasculitic neuropathies can be divided into two groups: systemic and non-systemic ones. The first sign of a vasculitic neuropathy is a progressive, painful mononeuropathy; the classic clinical presentation is the mononeuritis multiplex. It is characterized by general signs like fever, loss of weight, fatigue. In systemic vasculitis organ specific symptoms are also present. From the paraneoplastic diseases the subacute sensory neuropathy and the sensory neuronopathy are members of the immune-mediated neuropathies, being most frequently associated with small cell lung cancer.

  6. Motor neuropathies and lower motor neuron syndromes.

    Science.gov (United States)

    Verschueren, A

    2017-05-01

    Motor or motor-predominant neuropathies may arise from disease processes affecting the motor axon and/or its surrounding myelin. Lower motor neuron syndrome (LMNS) arises from a disease process affecting the spinal motor neuron itself. The term LMNS is more generally used, rather than motor neuronopathy, although both entities are clinically similar. Common features are muscle weakness (distal or proximal) with atrophy and hyporeflexia, but no sensory involvement. They can be acquired or hereditary. Immune-mediated neuropathies (multifocal motor neuropathy, motor-predominant chronic inflammatory demyelinating polyneuropathy) are important to identify, as effective treatments are available. Other acquired neuropathies, such as infectious, paraneoplastic and radiation-induced neuropathies are also well known. Focal LMNS is an amyotrophic lateral sclerosis (ALS)-mimicking syndrome especially affecting young adults. The main hereditary LMNSs in adulthood are Kennedy's disease, late-onset spinal muscular atrophy and distal hereditary motor neuropathies. Motor neuropathies and LMNS are all clinical entities that should be better known, despite being rare diseases. They can sometimes be difficult to differentially diagnose from other diseases, particularly from the more frequent ALS in its pure LMN form. Nevertheless, correct identification of these syndromes is important because their treatment and prognoses are definitely different. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Early onset (childhood) monogenic neuropathies.

    Science.gov (United States)

    Landrieu, Pierre; Baets, Jonathan

    2013-01-01

    Hereditary neuropathies (HN) with onset in childhood are categorized according to clinical presentation, pathogenic mechanism based on electrophysiology, genetic transmission and, in selected cases, pathological findings. Especially relevant to pediatrics are the items "secondary" versus "primary" neuropathy, "syndromic versus nonsyndromic," and "period of life." Different combinations of these parameters frequently point toward specific monogenic disorders. Ruling out a neuropathy secondary to a generalized metabolic disorder remains the first concern in pediatrics. As a rule, metabolic diseases include additional, orienting symptoms or signs, and their biochemical diagnosis is based on logical algorithms. Primary, motor sensory are the most frequent HN and are dominated by demyelinating autosomal dominant (AD) forms (CMT1). Other forms include demyelinating autosomal recessive (AR) forms, axonal AD/AR forms, and forms with "intermediate" electrophysiological phenotype. Peripheral motor neuron disorders are dominated by AR SMN-linked spinal muscular atrophies. (Distal) hereditary motor neuropathies represent 40 genes with various biological functions have been found to be responsible for primary HN. Many are responsible for various phenotypes, including some without the polyneuropathic trait, and some for various types of transmission.

  8. Autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1983-01-01

    The diagnosis of autonomic neuropathy is often difficult to establish, since clinical symptoms generally appear late in the course of the disease, and may be non-specific. A number of recently developed quantifiable and reproducible autonomic nerve function tests are reviewed, with emphasis on th...

  9. CONGENITAL SENSORY NEUROPATHY (HSAN II

    Directory of Open Access Journals (Sweden)

    Venkata Chalam

    2015-08-01

    Full Text Available A 5 year old girl having hereditary sensory neuropathy, type II manifesting as congenital absence of pain sensation and trophic changes in the skin is reported. This child presented with presented with multiple ulcers over hands and feet since 2 years of age. The ulcers were non - healing type with serosanguineous discharge. There is abnormal gait and weakness in upper and lower limbs. On examination there are deep ulcers measuring 5x7x2cms over left feet. Fingers of both hands and feet were mutilated with loss of phalanges, sensations to fine touch, pain and temperature are decreased bilaterally below the mid arm and feet, vibration sensations were normal, proprioception could not be tested due to deformities. Sensory and motor nerve conduction studies showed evidence of sensorimotor axonal neuropathy.

  10. Abnormal calcium homeostasis in peripheral neuropathies.

    Science.gov (United States)

    Fernyhough, Paul; Calcutt, Nigel A

    2010-02-01

    Abnormal neuronal calcium (Ca2+) homeostasis has been implicated in numerous diseases of the nervous system. The pathogenesis of two increasingly common disorders of the peripheral nervous system, namely neuropathic pain and diabetic polyneuropathy, has been associated with aberrant Ca2+ channel expression and function. Here we review the current state of knowledge regarding the role of Ca2+ dyshomeostasis and associated mitochondrial dysfunction in painful and diabetic neuropathies. The central impact of both alterations of Ca2+ signalling at the plasma membrane and also intracellular Ca2+ handling on sensory neurone function is discussed and related to abnormal endoplasmic reticulum performance. We also present new data highlighting sub-optimal axonal Ca2+ signalling in diabetic neuropathy and discuss the putative role for this abnormality in the induction of axonal degeneration in peripheral neuropathies. The accumulating evidence implicating Ca2+ dysregulation in both painful and degenerative neuropathies, along with recent advances in understanding of regional variations in Ca2+ channel and pump structures, makes modulation of neuronal Ca2+ handling an increasingly viable approach for therapeutic interventions against the painful and degenerative aspects of many peripheral neuropathies.

  11. Histopathological heterogeneity of neuropathy in insulin-dependent and non-insulin-dependent diabetes, and demonstration of axo-glial dysjunction in human diabetic neuropathy.

    OpenAIRE

    Sima, A A; Nathaniel, V; Bril, V; McEwen, T A; Greene, D A

    1988-01-01

    Altered sorbitol and myo-inositol metabolism, (Na,K)-ATPase function, electrochemical sodium gradients, axonal swelling, and distortion and disruption of the node of Ranvier ("axo-glial dysjunction") directly implicate hyperglycemia in the pathogenesis of neuropathy in diabetic rats, but the relevance of this sequence to clinical neuropathy in heterogeneous groups of diabetic patients remains to be established. Fascicular sural nerve morphometry in 11 patients with neuropathy complicating ins...

  12. Genes for hereditary sensory and autonomic neuropathies : a genotype-phenotype correlation

    NARCIS (Netherlands)

    Rotthier, Annelies; Baets, Jonathan; De Vriendt, Els; Jacobs, An; Auer-Grumbach, Michaela; Levy, Nicolas; Bonello-Palot, Nathalie; Kilic, Sara Sebnem; Weis, Joachim; Nascimento, Andres; Swinkels, Marielle; Kruyt, Moyo C.; Jordanova, Albena; De Jonghe, Peter; Timmerman, Vincent

    2009-01-01

    Hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders characterized by axonal atrophy and degeneration, exclusively or predominantly affecting the sensory and autonomic neurons. So far, disease-associated mutations have been identified in seven g

  13. Axonopathy in peripheral neuropathies: Mechanisms and therapeutic approaches for regeneration.

    Science.gov (United States)

    Landowski, Lila M; Dyck, P James B; Engelstad, JaNean; Taylor, Bruce V

    2016-10-01

    Peripheral neuropathies (PNs) are injuries or diseases of the nerves which arise from varied aetiology, including metabolic disease, trauma and drug toxicity. The clinical presentation depends on the type of neuropathy, and may include the loss of motor, sensory and autonomic functions, or development of debilitating neuropathic pain distal to the injury site. It can be challenging to identify the aetiology of PNs, as the clinical syndromes are often indistinct. However, the mechanisms that underlie pathological changes in peripheral neuropathy are fundamentally different, depending on the trigger. This review focuses on the axonopathy observed in two frequently encountered forms of peripheral neuropathy, diabetic neuropathy and chemotherapy-induced neuropathy. A key manifestation of axonopathy in PN is the degeneration of terminal arbors of peripheral nerves, resulting in a loss of epidermal nerve fibres and inappropriate termination of nerve endings. Many symptoms of PN arise from aberrant termination of nerve endings, and the underlying axonopathy may be non-reversible, as nerve regeneration after injury and disease is often poor, absent, or aberrant. Directed guidance of terminal arbors back into the epidermis is therefore a suggested approach to treat peripheral neuropathy. This review will outline potential strategies to enhance and guide axonal regeneration and reinnervation in the skin. Using diabetic neuropathy and chemotherapy-induced neuropathy as specific examples, this review examines the setbacks encountered with the translation of growth factors into therapeutics for human neuropathy, and suggests a number of approaches for topical drug delivery.

  14. Lyme borreliosis neuropathy. A case report.

    Science.gov (United States)

    Deltombe, T; Hanson, P; Boutsen, Y; Laloux, P; Clerin, M

    1996-01-01

    Lyme borreliosis is responsible for a large variety of peripheral neurologic manifestations including axonal polyneuropathy, radiculopathy, and facial nerve palsy. The prevalence of the disease must draw our attention on the possible responsibility of Borrelia burgdorferi in the pathogenesis of such symptomatology. Electrophysiologic studies demonstrate a proximal and distal axonal involvement, whereas neuropathologic studies suggest that vasculitis might be one of the primary pathophysiologic mechanisms. Electromyography provides a useful diagnostic tool and an important measure of response to treatment. Although peripheral neuropathy usually improves, our case report confirms the fact that chronic neurologic manifestations may not consistently resolve with appropriate treatment.

  15. Upregulation of inward rectifying currents and Fabry disease neuropathy.

    Science.gov (United States)

    Geevasinga, Nimeshan; Tchan, Michel; Sillence, David; Vucic, Steve

    2012-12-01

    Peripheral neuropathy and neuropathic pain are common clinical manifestations of Fabry disease (FD). Although the mechanisms underlying the development of sensory neuropathy remain to be fully elucidated, a chronic ischemic process was proposed. Consequently, this study utilized axonal excitability techniques to gain further insights into the pathophysiological mechanisms underlying the development of FD neuropathy. Median motor and sensory axonal excitability studies were undertaken in 13 FD patients and results were compared to 19 healthy subjects. A "fanning-in" of threshold electrotonus, suggestive of membrane depolarization, was evident only in motor axons in FD patients. In contrast, the sensory axons exhibited a lower threshold in FD (p < 0.05) and a significantly increased hyperpolarizing current/threshold (I/V) gradient (FD 0.48 ± 0.03; controls, 0.31 ± 0.02, p < 0.001), which correlated with clinical scores of disease severity (Rho = 0.65, p < 0.05), neuropathy (Rho = 0.54, p < 0.05) and neuropathic pain (Rho = 0.56, p < 0.05). These findings indicate that upregulation of I(h) , rather than ischemia, may underlie the sensory symptoms and possibly development of neuropathy in FD. Modulation of sensory I(h) may prove therapeutically useful in Fabry disease.

  16. Pathogenic mechanisms in inflammatory and paraproteinaemic peripheral neuropathies.

    Science.gov (United States)

    Rinaldi, Simon; Bennett, David L H

    2014-10-01

    This review summarizes the major recent developments in understanding of pathogenic mechanisms in inflammatory and paraproteinaemic neuropathies. In the inflammatory neuropathies, there has been a particular focus on antibody-mediated disease affecting the nodal/paranodal regions. Disruption of electrical integrity at these sites on the axonal membrane can cause conduction block without other electrophysiological features of demyelination, which has led to calls for a revision in the classification of axonal versus demyelinating neuropathies to include the new category of 'nodo-paranodopathies'. There has likewise been an expansion in knowledge regarding the diverse disease mechanisms of the paraproteinaemic neuropathies. These also include disease mediated by antibodies binding to peripheral nerve antigens, but additionally encompass immune complex deposition, cellular infiltration, and cytokine production. An increasing range of laboratory tests for antibodies, growth factors, and cytokines are proposed as useful in the management of inflammatory and paraproteinaemic neuropathies. Furthermore, the traditional electrodiagnostic classification into axonal and demyelinating neuropathy may not always accurately reflect the underlying disease process. Understanding how these paraclinical tests aid in identifying the underlying disease has relevance to the practising clinician both in terms of diagnosis and for the selection of rational treatments.

  17. Cobalt inhibits motility of axonal mitochondria and induces axonal degeneration in cultured dorsal root ganglion cells of rat.

    Science.gov (United States)

    Kikuchi, Shin; Ninomiya, Takafumi; Kohno, Takayuki; Kojima, Takashi; Tatsumi, Haruyuki

    2017-06-27

    Cobalt is a trace element that localizes in the human body as cobalamin, also known as vitamin B12. Excessive cobalt exposure induces a peripheral neuropathy, the mechanisms of which are yet to be elucidated. We investigated how cobalt may affect mitochondrial motility in primary cultures of rat dorsal root ganglion (DRG). We observed mitochondrial motility by time-lapse imaging after DsRed2 tagging via lentivirus, mitochondrial structure using transmission electron microscopy (TEM), and axonal swelling using immunocytochemical staining. The concentration of cobaltous ion (Co(2+)) required to significantly suppress mitochondrial motility is lower than that required to induce axonal swelling following a 24-h treatment. Exposure to relatively low concentrations of Co(2+) for 48 h suppressed mitochondrial motility without leading to axonal swelling. TEM images indicated that Co(2+) induces mitochondrial destruction. Our results show that destruction of the axonal mitochondria precedes the axonal degeneration induced by Co(2+) exposure.

  18. The distal hereditary motor neuropathies.

    Science.gov (United States)

    Rossor, Alexander M; Kalmar, Bernadett; Greensmith, Linda; Reilly, Mary M

    2012-01-01

    The distal hereditary motor neuropathies (dHMN) comprise a heterogeneous group of diseases that share the common feature of a length-dependent predominantly motor neuropathy. Many forms of dHMN have minor sensory abnormalities and/or a significant upper-motor-neuron component, and there is often an overlap with the axonal forms of Charcot-Marie-Tooth disease (CMT2) and with juvenile forms of amyotrophic lateral sclerosis and hereditary spastic paraplegia. Eleven causative genes and four loci have been identified with autosomal dominant, recessive and X-linked patterns of inheritance. Despite advances in the identification of novel gene mutations, 80% of patients with dHMN have a mutation in an as-yet undiscovered gene. The causative genes have implicated proteins with diverse functions such as protein misfolding (HSPB1, HSPB8, BSCL2), RNA metabolism (IGHMBP2, SETX, GARS), axonal transport (HSPB1, DYNC1H1, DCTN1) and cation-channel dysfunction (ATP7A and TRPV4) in motor-nerve disease. This review will summarise the clinical features of the different subtypes of dHMN to help focus genetic testing for the practising clinician. It will also review the neuroscience that underpins our current understanding of how these mutations lead to a motor-specific neuropathy and highlight potential therapeutic strategies. An understanding of the functional consequences of gene mutations will become increasingly important with the advent of next-generation sequencing and the need to determine the pathogenicity of large amounts of individual genetic data.

  19. [Inflammatory neuropathies and multineuritis].

    Science.gov (United States)

    Kuntzer, Thierry; Chofflon, Michel

    2009-12-02

    Inflammatory neuropathies include those neuropathies in which the diagnosis, outcome and type of treatment are badly known, the reason of this review. They are expressed as diffuse (such as CIDP and ganglionopathies), multifocal (vasculitic neuropathy) or focal (MMN; plexopathies; immune reconstitution inflammatory syndrome). These forms of neuropathies are important to be known because the beneficial therapeutic possibilities of immunosuppression.

  20. Diabetic autonomic neuropathy.

    Science.gov (United States)

    Freeman, Roy

    2014-01-01

    Diabetes mellitus is the commonest cause of an autonomic neuropathy in the developed world. Diabetic autonomic neuropathy causes a constellation of symptoms and signs affecting cardiovascular, urogenital, gastrointestinal, pupillomotor, thermoregulatory, and sudomotor systems. Several discrete syndromes associated with diabetes cause autonomic dysfunction. The most prevalent of these are: generalized diabetic autonomic neuropathy, autonomic neuropathy associated with the prediabetic state, treatment-induced painful and autonomic neuropathy, and transient hypoglycemia-associated autonomic neuropathy. These autonomic manifestations of diabetes are responsible for the most troublesome and disabling features of diabetic peripheral neuropathy and result in a significant proportion of the mortality and morbidity associated with the disease.

  1. Cranial nerves palsy as an initial feature of an early onset distal hereditary motor neuropathy--a new distal hereditary motor neuropathy phenotype.

    Science.gov (United States)

    Haberlová, J; Claeys, K G; De Jonghe, P; Seeman, P

    2009-06-01

    Distal hereditary motor neuropathy is a heterogeneous group of disorders characterised by a pure motor axonal neuropathy. It is occasionally associated with additional signs such as facial weakness, vocal cord paralysis, weakness of the diaphragm, and pyramidal signs. Although predominantly the inheritance is autosomal dominant, all types of inheritance have been described. Here we report a Czech family with cranial nerves palsy as an initial feature of a non progressive infantile onset dominant distal hereditary motor neuropathy. This family may represent a new subtype of distal hereditary motor neuropathy.

  2. Management of Diabetic Neuropathy

    OpenAIRE

    Ali, Raymond Azman

    2003-01-01

    Diabetes mellitus is the commonest cause of neuropathy worldwide. Diabetic neuropathy (DN) develops in about 4–10% of diabetic patients after 5 years and in 15% after 20 years. Four main mechanisms have been postulated to underlie the pathogenesis of DN. Diabetic neuropathy can be divided into symmetrical and asymmetrical neuropathies. Diabetic Autonomic Neuropathy (DAN) parallels the severity of DSN, and affects primarily the cardiovascular, gastrointestinal, genitourinary and integumentary ...

  3. Histological, Scanning And Transmission Electron Microscopic Studies On The Possible Protective Role Of Ginger Extract Against AcrylamideInduced Intestinal Damage In Mice

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    Hala Galal El-Tantawi

    2007-12-01

    Full Text Available Objective: This study was carried out to evaluate the protective effect of ginger Zingeber officinale extract (ZOE against the acrylamide (AC which is an industrial chemical used in water treatment and it is synthesized during cooking of starch food at high temperature. Method: Thirty adult male albino mice, each weighs 20-25 g were divided into three groups (10 mice/group: (Icontrol group. (IIacrylamide treated group. (III acrylamide & ginger group. Acrylamide was given to experimental animals in the drinking water at a non-lethal dose of 200 p.p.m for 10 weeks (3 days/week. Ginger extract was orally administrated at 50 mg/L (~5 ml/day for 10 weeks (3 days/week. The ileum samples were collected for light microscope study and for scanning and transmission electron microscope examination. Results: This study revealed that acrylamide induces pathological changes of the ileum of the treated mice specially the absorptive epithelial cells. The scanning electron microscopic study revealed damage of the ileal villi, some red blood corpuscles appeared at the site of damage. The transmission electron microscopic examination clearly demonstrated degeneration of most cell organelles as mitochondria, deterioration and degranulation of the rough endoplasmic reticulum, dilatation of Golgi apparatus. Conclusion: The administration of ginger extract decreased the histological alterations and ensuring the anti-inflammatory, and antitoxic effects of ZOE at its chosen dosage level

  4. Optic neuropathies: characteristic features and mechanisms of retinal ganglion cell loss.

    Science.gov (United States)

    You, Yuyi; Gupta, Vivek K; Li, Jonathan C; Klistorner, Alexander; Graham, Stuart L

    2013-01-01

    Optic neuropathy refers to dysfunction and/or degeneration of axons of the optic nerve with subsequent optic nerve atrophy. A common feature of different optic neuropathies is retinal ganglion cell (RGC) apoptosis and axonal damage. Glaucoma and optic neuritis are the two major degenerative causes of optic nerve damage. Here, we review the anatomy and pathology of the optic nerve, and etiological categories of optic neuropathies, and discuss rodent models that can mimic these conditions. Electrophysiology can reveal signature features of RGC damage using the pattern electroretinogram (PERG), scotopic threshold response (STR) and photopic negative response (PhNR). The amplitude of the visual evoked potential (VEP) also reflects RGC axonal damage. The neurotrophin-mediated survival pathways, as well as the extrinsic and intrinsic cell apoptotic pathways, play a critical role in the pathogenesis of RGC loss. Finally, promising neuroprotective approaches based on the molecular signaling are analyzed for the treatment of optic neuropathies.

  5. Anatomy of the optic nerve head and glaucomatous optic neuropathy.

    Science.gov (United States)

    Radius, R L

    1987-01-01

    The mechanism of axon damage in eyes with glaucomatous optic neuropathy remains undefined. Interestingly, it has been observed that, although the entire nerve cross-section may be involved by the nerve damage, in many instances, the superior and inferior axon bundles are preferentially affected by the pressure insult. Thus, recent studies by many investigators have stressed a re-examination of the optic nerve head anatomy, including the nerve head microcirculation, the glial and connective tissue elements within the nerve head, and the morphology of the axons themselves. Any correlation between regional differences in this anatomy and the preferential involvement by specific axon bundles within the nerve head by the pressure insult may suggest some further insight into the mechanisms underlying the pressure-induced axon loss in glaucomatous eyes.

  6. Pathogenesis of immune-mediated neuropathies.

    Science.gov (United States)

    Dalakas, Marinos C

    2015-04-01

    Autoimmune neuropathies occur when immunologic tolerance to myelin or axonal antigens is lost. Even though the triggering factors and the underling immunopathology have not been fully elucidated in all neuropathy subsets, immunological studies on the patients' nerves, transfer experiments with the patients' serum or intraneural injections, and molecular fingerprinting on circulating autoantibodies or autoreactive T cells, indicate that cellular and humoral factors, either independently or in concert with each other, play a fundamental role in their cause. The review is focused on the main subtypes of autoimmune neuropathies, mainly the Guillain-Barré syndrome(s), the Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), the Multifocal Motor Neuropathy (MMN), and the IgM anti-MAG-antibody mediated neuropathy. It addresses the factors associated with breaking tolerance, examines the T cell activation process including co-stimulatory molecules and key cytokines, and discusses the role of antibodies against peripheral nerve glycolipids or glycoproteins. Special attention is given to the newly identified proteins in the nodal, paranodal and juxtaparanodal regions as potential antigenic targets that could best explain conduction failure and rapid recovery. New biological agents against T cells, cytokines, B cells, transmigration and transduction molecules involved in their immunopathologic network, are discussed as future therapeutic options in difficult cases. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.

  7. Peripheral neuropathy in Whipples disease: a case report.

    Science.gov (United States)

    Rusina, R; Keller, O; Síma, R; Zámečník, J

    2012-04-01

    Whipples disease is a chronic multisystem inflammatory disease with predominantly gastrointestinal manifestations due to Tropheryma whipplei infection. Typical neurological abnormalities include dementia, eye movement abnormalities, hypothalamic dysfunction and oculomasticatory myorhythmias. The literature on peripheral neuropathy in Whipples disease is sparse and the involvement of peripheral nerves in Whipples disease has not been documented convincingly so far. We present a case of Whipples disease presenting by axonal peripheral neuropathy without gastrointestinal involvement. The diagnosis was confirmed by a sural nerve biopsy and consequent PCR of the sample. All clinical signs disappeared progressively during the antibiotic therapy. Two years after the T. whipplei infection, the patient developed dopa-sensitive Parkinson's disease, although these two events seem to be unrelated. This case illustrates the value of peripheral nerve biopsy in cases of axonal neuropathy of unexplained origin and extends the clinical spectrum of Whipples disease to a new modality.

  8. Computing along the axon

    Institute of Scientific and Technical Information of China (English)

    Chen Haiming; Tseren-Onolt Ishdorj; Gheorghe Pǎun

    2007-01-01

    A special form of spiking neural P systems, called axon P systems, corresponding to the activity of Ranvier nodes of neuron axon, is considered and a class of SN-like P systems where the computation is done along the axon is introduced and their language generative power is investigated.

  9. Charcot-Marie-Tooth disease and other inherited neuropathies.

    Science.gov (United States)

    Saporta, Mario A

    2014-10-01

    Inherited peripheral neuropathies are among the most common genetic neuromuscular disorders worldwide. However, their diagnosis can be challenging due to genotypic and phenotypic variability. Charcot-Marie-Tooth disease (CMT), the most common form, is associated with mutations or copy-number variations in over 70 genes, representing proteins with fundamental roles in the development and function of Schwann cells and peripheral axons. Other genetic peripheral neuropathies are associated with multisystem manifestations, including familial amyloid neuropathy and neuropathies associated with metabolic or other genetic syndromes. This article reviews the most recent discoveries in the field and how they are changing the way neurologists diagnose this specific group of peripheral neuropathies. In the past few years, several large cohort studies on the molecular diagnosis of CMT have been published, providing guidelines for genetic testing in clinical practice. In the same period, next-generation sequencing technology has accelerated the discovery of new CMT genes, expanding our knowledge on genotype-phenotype correlations. Recent advances in sequencing technology and genotype-phenotype correlation studies are changing the way neurologists diagnose inherited neuropathies. New therapeutic strategies for familial amyloid neuropathy are paving the way for innovative treatments for genetic neuropathies.

  10. [Acute Sensory Neuropathies and Acute Autonomic Neuropathies].

    Science.gov (United States)

    Koike, Haruki

    2015-11-01

    From the perspective of neuropathies with an acute onset mimicking that of Guillain-Barré syndrome (GBS), cases with profound sensory and/or autonomic impairment without any significant weakness have been reported. Although the possibility of infectious or toxic etiologies should be carefully excluded, immune mechanisms similar to those in GBS are suggested to be involved in these so-called acute sensory neuropathies and acute autonomic neuropathies. The types of neuropathy include those with predominant sensory manifestations, predominant autonomic manifestations such as autoimmune autonomic ganglionopathy, and both sensory and autonomic manifestations such as acute autonomic and sensory neuropathy. Neuronopathy in the sensory and/or autonomic ganglia (i.e., ganglionopathy) has been commonly suggested in patients with these types of neuropathies. The presence of Anti-GD1b antibodies has been reported in some of the patients with acute sensory neuropathy with deep sensory impairment, whereas anti-ganglionic acetylcholine receptor antibodies are reported to be present in half of the patients with autoimmune autonomic ganglionopathy. The discovery of anti-ganglionic acetylcholine receptor antibodies significantly expanded the spectrum of autoimmune autonomic ganglionopathy. This is because some of the patients with chronic progression mimicking neurodegenerative diseases such as pure autonomic failure were positive for these antibodies. In contrast, pathologically significant autoantibodies have not been identified in acute autonomic and sensory neuropathy. Further studies are needed to clarify the pathogenesis and the spectrum of these types of neuropathies.

  11. [Multifocal-motor neuropathy and motor neuropathy with multifocal conduction block (Lewis-Sumner syndrome)].

    Science.gov (United States)

    Finsterer, J; Mamoli, B

    1995-01-01

    Multifocal motor neuropathy, which mimics lower motor neuron disease, is a rare and curious demyelinating neuropathy characterised by slowly progressive, asymmetric limb weakness within the distribution of individual peripheral nerves, wasting, cramps, fasciculations and rare sensory involvement, but without upper motor neuron signs. The cardinal feature and primary pathophysiological basis for the weakness is the multifocal motor conduction block which remains stable for years at the same site and is confined to motor axons. It is defined as > 50% reduction in both the CMAP and the negative peak area on proximal stimulation, as compared with the distal stimulus response without any change in the negative peak duration. Nerves at the site of the conduction block show demyelination, endoneural edema, rudimentary onion bulbs and lymphocytic inflammation. Sensory nerves may show mild demyelination, axon loss and lymphocytic inflammation. The majority of patients shows elevated titers of anti-glycolipid antibodies, which may block the Na+ channels, produce demyelination or interfere with remyelination. However, their role in the pathogenesis of multifocal motor neuropathy remains uncertain. Multifocal motor neuropathy is regarded as the predominantly motor variant of chronic inflammatory demyelinating polyneuropathy and can be treated best with immunoglobulins and cyclophosphamide.

  12. Clinicopathological study of vasculitic peripheral neuropathy

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    Rong-fang DONG

    2014-06-01

    Full Text Available Objective To summarize the clinical features and neuropathological characteristics in patients with vasculitic peripheral neuropathy (VPN. Methods Clinical manifestations, laboratory examination and neuromuscular biopsy characteristics of 11 patients with VPN were retrospectively analyzed. The lesion of nerve, muscle and skin was observed under optical and electron microscope. Immunohistochemical analyses were carried out to detect neurofilament (NF, myelin basic protein (MBP, peripheral myelin protein 22 (PMP22 and S-100 protein (S-100 and further observing the neuropathy of neuraxon, myelin sheath and Schwann cells, and to detect human leukocyte antigen DR (HLA-DR, CD68, CD3 and CD20 to observe inflammatory cell infiltration. Immunofluorescent staining was used to detect the deposition of IgA, IgM, IgG and addiment C3 on vascular wall. The staining of periodic acid-Schiff (PAS, NADH-tetrazolium reductase (NADH-TR and modified Gomori trichrome (MGT were used to judge the myopathy. Results 1 Angiopathies were mainly manifested by small vessels of epineurium and perineurium, and infiltrated inflammatory cells were mainly CD3 + T cells. Three patients had active vasculitis, and 8 patients had non-active vasculitis. Among these 8 patients, 4 patients mainly presented fibrous obliteration of blood vessel, with slight inflammatroy cell infiltration, and the other 4 patients mainly showed perivascular inflammation. 2 Neuropathy: 6 patients had axon degeneration, and 5 patients had axon degeneration associated with demyelination. All of them demonstrated a reduction in myelinated fibers, mainly large diameter myelinated fibers, even on end-stage. 3 Muscle biopsy showed neurogenic atrophy. 4 Clinicopathologic diagnosis: among these 11 patients, 8 patients were diagnosed as systemic vasculitic peripheral neuropathy (SVPN, among whom 5 patients were diagnosed as primary systemic vasculitis [including 1 patient as Churg-Strauss syndrome (CSS, 2 patients as

  13. Fcγ receptor-mediated inflammation inhibits axon regeneration.

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    Gang Zhang

    Full Text Available Anti-glycan/ganglioside antibodies are the most common immune effectors found in patients with Guillain-Barré Syndrome, which is a peripheral autoimmune neuropathy. We previously reported that disease-relevant anti-glycan autoantibodies inhibited axon regeneration, which echo the clinical association of these antibodies and poor recovery in Guillain-Barré Syndrome. However, the specific molecular and cellular elements involved in this antibody-mediated inhibition of axon regeneration are not previously defined. This study examined the role of Fcγ receptors and macrophages in the antibody-mediated inhibition of axon regeneration. A well characterized antibody passive transfer sciatic nerve crush and transplant models were used to study the anti-ganglioside antibody-mediated inhibition of axon regeneration in wild type and various mutant and transgenic mice with altered expression of specific Fcγ receptors and macrophage/microglia populations. Outcome measures included behavior, electrophysiology, morphometry, immunocytochemistry, quantitative real-time PCR, and western blotting. We demonstrate that the presence of autoantibodies, directed against neuronal/axonal cell surface gangliosides, in the injured mammalian peripheral nerves switch the proregenerative inflammatory environment to growth inhibitory milieu by engaging specific activating Fcγ receptors on recruited monocyte-derived macrophages to cause severe inhibition of axon regeneration. Our data demonstrate that the antibody orchestrated Fcγ receptor-mediated switch in inflammation is one mechanism underlying inhibition of axon regeneration. These findings have clinical implications for nerve repair and recovery in antibody-mediated immune neuropathies. Our results add to the complexity of axon regeneration in injured peripheral and central nervous systems as adverse effects of B cells and autoantibodies on neural injury and repair are increasingly recognized.

  14. Genetic dysfunction of MT-ATP6 causes axonal Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Pitceathly, Robert D S

    2012-09-11

    Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder, affecting 1 in 2,500 individuals. Mitochondrial DNA (mtDNA) mutations are not generally considered within the differential diagnosis of patients with uncomplicated inherited neuropathy, despite the essential requirement of ATP for axonal function. We identified the mtDNA mutation m.9185T>C in MT-ATP6, encoding the ATP6 subunit of the mitochondrial ATP synthase (OXPHOS complex V), at homoplasmic levels in a family with mitochondrial disease in whom a severe motor axonal neuropathy was a striking feature. This led us to hypothesize that mutations in the 2 mtDNA complex V subunit encoding genes, MT-ATP6 and MT-ATP8, might be an unrecognized cause of isolated axonal CMT and distal hereditary motor neuropathy (dHMN).

  15. Peripheral neuropathies 1988

    Energy Technology Data Exchange (ETDEWEB)

    Assal, J.P.; Liniger, C.

    1990-01-01

    The authors present results and experience in sixteen specific disciplines related to the study of nerve physiopathology, diagnosis and treatment. Twenty-two different peripheral neuropathies are presented, and different models related to health care strategies are discussed. The authors report on Inflammatory and autoimmune neuropathies and Genetic neuropathies.

  16. Diabetic radiculoplexus neuropathies.

    Science.gov (United States)

    Laughlin, Ruple S; Dyck, P James B

    2014-01-01

    Diabetic radiculoplexus neuropathies (DRPN) are neuropathies clinically and pathologically distinct from the neuropathy typically associated with diabetes (DPN). DRPN are usually subacute in onset, painful, and often demonstrate a monophasic course with incomplete recovery. Pathologically, these neuropathies are due to ischemic injury from altered immunity and often have features suggestive or diagnostic of microvasculitis. Unlike DPN, immune therapy may be helpful in treatment of these conditions given their pathological substrate and therefore are important to identify early and distinguish from other neuropathies that occur in patient with diabetes.

  17. CIDP and other inflammatory neuropathies in diabetes - diagnosis and management.

    Science.gov (United States)

    Rajabally, Yusuf A; Stettner, Mark; Kieseier, Bernd C; Hartung, Hans-Peter; Malik, Rayaz A

    2017-09-15

    Distal symmetric polyneuropathy (DSPN) is the most common neuropathy to occur in diabetes mellitus. However, patients with diabetes can also develop inflammatory neuropathies, the most common and most treatable of which is chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Whether diabetes is a risk factor for CIDP remains under debate. Early studies suggested that patients with diabetes were at increased risk of CIDP, but epidemiological studies failed to confirm the association, and subsequent data have re-opened the debate. Inadequate interpretation of investigations and differentials between CIDP and other neuropathies that can occur in diabetes, such as DSPN, diabetic radiculoplexus neuropathies and vasculitic multiple mononeuropathy, might mean that CIDP is under-recognized. Despite a response rate of >80% to first-line therapies for CIDP in patients with or without diabetes, those with diabetes often present with greater disability owing to late referral and axonal pathology attributed to DSPN. The increasing worldwide prevalence of diabetes creates an urgent need to improve identification of potentially treatable neuropathies, such as CIDP. In this Review, we consider the features of CIDP in patients with diabetes, and discuss how these features can be used to differentiate the condition from other neuropathies. We also review the management options for CIDP and other inflammatory neuropathies in patients with diabetes.

  18. Molecular genetics of distal hereditary motor neuropathies.

    Science.gov (United States)

    Irobi, Joy; De Jonghe, Peter; Timmerman, Vincent

    2004-10-01

    Inherited peripheral neuropathies comprise a wide variety of diseases primarily affecting the peripheral nervous system. The best-known peripheral neuropathy is Charcot-Marie-Tooth disease (CMT) described in 1886 by J.-M. Charcot, P. Marie and H.H. Tooth. In 1980, A.E. Harding and P.K. Thomas showed that in a large group of individuals with CMT, several only had motor abnormalities on clinical and electrophysiological examination, whereas sensory abnormalities were absent. This exclusively motor variant of CMT was designated as spinal CMT or hereditary distal spinal muscular atrophy, and included in the distal hereditary motor neuropathies (distal HMN). The distal HMN are clinically and genetically heterogeneous and are subdivided according to the mode of inheritance, age at onset and clinical evolution. Since the introduction of positional cloning, 12 chromosomal loci and seven disease-causing genes have been identified for autosomal dominant and recessive distal HMN. Most of the genes involved have housekeeping functions, as in RNA processing, translation synthesis, glycosylation, stress response, apoptosis, but also axonal trafficking and editing. Functional characterization of the mutations will help to unravel the cellular processes that underlie the specificity of motor neuropathies leading to neurogenic muscular atrophy of distal limb muscles. Here we review the recent progress of the molecular genetics of distal HMN and discuss the genes implicated.

  19. Role of calpains in the injury-induced dysfunction and degeneration of the mammalian axon.

    Science.gov (United States)

    Ma, Marek

    2013-12-01

    Axonal injury and degeneration, whether primary or secondary, contribute to the morbidity and mortality seen in many acquired and inherited central nervous system (CNS) and peripheral nervous system (PNS) disorders, such as traumatic brain injury, spinal cord injury, cerebral ischemia, neurodegenerative diseases, and peripheral neuropathies. The calpain family of proteases has been mechanistically linked to the dysfunction and degeneration of axons. While the direct mechanisms by which transection, mechanical strain, ischemia, or complement activation trigger intra-axonal calpain activity are likely different, the downstream effects of unregulated calpain activity may be similar in seemingly disparate diseases. In this review, a brief examination of axonal structure is followed by a focused overview of the calpain family. Finally, the mechanisms by which calpains may disrupt the axonal cytoskeleton, transport, and specialized domains (axon initial segment, nodes, and terminals) are discussed.

  20. Autoimmune neuropathies associated to rheumatic diseases.

    Science.gov (United States)

    Martinez, Alberto R M; Faber, Ingrid; Nucci, Anamarli; Appenzeller, Simone; França, Marcondes C

    2017-04-01

    Systemic manifestations are frequent in autoimmune rheumatic diseases and include peripheral nervous system damage. Neuron cell body, axons and myelin sheath may all be affected in this context. This involvement results in severe and sometimes disabling symptoms. Sensory, motor and autonomic features may be present in different patterns that emerge as peculiar clinical pictures. Prompt recognition of these neuropathies is pivotal to guide treatment and reduce the risks of long term disability. In this review, we aim to describe the main immune-mediated neuropathies associated to rheumatic diseases: sensory neuronopathies, multiple mononeuropathies and chronic inflammatory demyelinating polyradiculoneuropathy, with an emphasis on clinical features and therapeutic options. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. [Genetics of neuropathies].

    Science.gov (United States)

    Gess, B; Schirmacher, A; Young, P

    2013-02-01

    Hereditary neuropathies belong to the most common neurogenetic disorders. They appear mostly as sensory and motor neuropathies but there are also pure sensory, pure motor as well as sensory and autonomic hereditary neuropathies. In clinical practice, knowledge of hereditary neuropathies is important in order to recognize them among polyneuropathies and achieve a successful genetic diagnosis. The molecular genetics of hereditary neuropathies are very heterogeneous with currently more than 40 known disease-causing genes. The 4 most common genes account for almost 90% of the genetically diagnosed hereditary neuropathies. In this review article we provide an overview of the currently known genes and propose a rational genetic work-up protocol of the most common genes.

  2. Use of pyridoxine and pyridostigmine in children with vincristine-induced neuropathy.

    Science.gov (United States)

    Akbayram, Sinan; Akgun, Cihangir; Doğan, Murat; Sayin, Refah; Caksen, Huseyin; Oner, Ahmet Faik

    2010-06-01

    Four children with vincristine (VCR)-induced neuropathy are being reported. All cases were followed with the diagnosis of acute lymphoblastic leukemia. Two were boys aged between 2 and 13 year. Electromyographic examination consisted of sensoriomotor polyneuropathy with axonal involvement in three patients. In another patient, it consisted of motor axonal polyneuropathy. In all patients, pyridoxine and pyridostigmine were successfully used in the treatment of VCR-induced neuropathy. They recovered completely with this drug combination. Recovering period of symptoms was between 1-2 week.

  3. Inherited Peripheral Neuropathies

    Science.gov (United States)

    Saporta, Mario A.; Shy, Michael E.

    2013-01-01

    SYNOPSIS Charcot Marie Tooth disease (CMT) is a heterogeneous group of inherited peripheral neuropathies in which the neuropathy is the sole or primary component of the disorder, as opposed to diseases in which the neuropathy is part of a more generalized neurological or multisystem syndrome. Due to the great genetic heterogeneity of this condition, it can be challenging for the general neurologist to diagnose patients with specific types of CMT. Here, we review the biology of the inherited peripheral neuropathies, delineate major phenotypic features of the CMT subtypes and suggest strategies for focusing genetic testing. PMID:23642725

  4. Axonal GABAA receptors.

    Science.gov (United States)

    Trigo, Federico F; Marty, Alain; Stell, Brandon M

    2008-09-01

    Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.

  5. Morphologic Changes in Autonomic Nerves in Diabetic Autonomic Neuropathy

    Directory of Open Access Journals (Sweden)

    Heung Yong Jin

    2015-12-01

    Full Text Available Diabetic neuropathy is one of the major complications of diabetes, and it increases morbidity and mortality in patients with both type 1 diabetes mellitus (T1DM and type 2 diabetes mellitus (T2DM. Because the autonomic nervous system, for example, parasympathetic axons, has a diffuse and wide distribution, we do not know the morphological changes that occur in autonomic neural control and their exact mechanisms in diabetic patients with diabetic autonomic neuropathy (DAN. Although the prevalence of sympathetic and parasympathetic neuropathy is similar in T1DM versus T2DM patients, sympathetic nerve function correlates with parasympathetic neuropathy only in T1DM patients. The explanation for these discrepancies might be that parasympathetic nerve function was more severely affected among T2DM patients. As parasympathetic nerve damage seems to be more advanced than sympathetic nerve damage, it might be that parasympathetic neuropathy precedes sympathetic neuropathy in T2DM, which was Ewing's concept. This could be explained by the intrinsic morphologic difference. Therefore, the morphological changes in the sympathetic and parasympathetic nerves of involved organs in T1DM and T2DM patients who have DAN should be evaluated. In this review, evaluation methods for morphological changes in the epidermal nerves of skin, and the intrinsic nerves of the stomach will be discussed.

  6. Severe peripheral neuropathy following gastric bypass surgery for morbid obesity.

    OpenAIRE

    Maryniak, O.

    1984-01-01

    Severe weakness in the limbs developed in a young woman 3 1/2 months after successful gastric bypass surgery for morbid obesity. Electromyography confirmed the clinical impression of generalized axonal polyneuropathy. Vitamin B replacement therapy was started. The gastric bypass was not reversed, and the patient continued to lose weight while undergoing rehabilitation. After 10 months she had almost fully recovered. Her total weight loss was 76 kg. Neuropathy is an uncommon but serious compli...

  7. Anterior ischemic optic neuropathy precipitated by acute primary angle closure

    Directory of Open Access Journals (Sweden)

    Choudhari Nikhil

    2010-01-01

    Full Text Available A 59-year-old man with a history of longstanding systemic hypotension developed asymmetric non-arteritic anterior ischemic optic neuropathy (NAION apparently precipitated by bilateral sequential acute primary angle closure. NAION is very rarely reported in association with raised intraocular pressure. In contrast to optical coherence tomography, the failure of scanning laser polarimetry to detect axonal swelling was another interesting finding. Possible reasoning for these observations is discussed.

  8. [Review of the recent literature on hereditary neuropathies].

    Science.gov (United States)

    Birouk, N

    2014-12-01

    The recent literature included interesting reports on the pathogenic mechanisms of hereditary neuropathies. The axonal traffic and its abnormalities in some forms of Charcot-Marie-Tooth (CMT) disease were particularly reviewed by Bucci et al. Many genes related to CMT disease code for proteins that are involved directly or not in intracellular traffic. KIF1B controls vesicle motility on microtubules. MTMR2, MTMR13 and FIG4 regulate the metabolism of phosphoinositide at the level of endosomes. The HSPs are involved in the proteasomal degradation. GDAP1 and MFN2 regulate the mitochondrial fission and fusion respectively and the mitochondial transport within the axon. Pareyson et al. reported a review on peripheral neuropathies in mitochondrial disorders. They used the term of "mitochondrial CMT" for the forms of CMT with abnormal mitochondrial dynamic or structure. Among the new entities, we can draw the attention to a proximal form of hereditary motor and sensory neuropathy with autosomal dominant inheritance, which is characterized by motor deficit with cramps and fasciculations predominating in proximal muscles. Distal sensory deficit can be present. The gene TFG on chromosome 3 has been recently identified to be responsible for this form. Another rare form of axonal autosomal recessive neuropathy due to HNT1 gene mutation is characterized by the presence of hands myotonia that appears later than neuropathy but constitute an interesting clinical hallmark to orientate the diagnosis of this form. In terms of differential diagnosis, CMT4J due to FIG4 mutation can present with a rapidly progressive and asymmetric weakness that resembles CIDP. Bouhy et al. made an interesting review on the therapeutic trials, animal models and the future therapeutic strategies to be developed in CMT disease.

  9. Axons take a dive

    Science.gov (United States)

    Tong, Cheuk Ka; Cebrián-Silla, Arantxa; Paredes, Mercedes F; Huang, Eric J; García-Verdugo, Jose Manuel; Alvarez-Buylla, Arturo

    2015-01-01

    In the walls of the lateral ventricles of the adult mammalian brain, neural stem cells (NSCs) and ependymal (E1) cells share the apical surface of the ventricular–subventricular zone (V–SVZ). In a recent article, we show that supraependymal serotonergic (5HT) axons originating from the raphe nuclei in mice form an extensive plexus on the walls of the lateral ventricles where they contact E1 cells and NSCs. Here we further characterize the contacts between 5HT supraependymal axons and E1 cells in mice, and show that suprependymal axons tightly associated to E1 cells are also present in the walls of the human lateral ventricles. These observations raise interesting questions about the function of supraependymal axons in the regulation of E1 cells. PMID:26413556

  10. Reproducibility of axon reflex-related vasodilation assessed by dynamic thermal imaging in healthy subjects

    NARCIS (Netherlands)

    M.D. Nieuwenhoff (Mariska D.); Y. Wu; F.J.P.M. Huygen (Frank); A.C. Schouten (A.); F.C.T. van der Helm (Frans); S.P. Niehof (Sjoerd)

    2016-01-01

    textabstractIntroduction Small nerve fiber dysfunction is an early feature of diabetic neuropathy. There is a strong clinical need for a non-invasive method to assess small nerve fiber function. Small nerve fibers mediate axon reflex-related vasodilation and play an important role in thermoregulati

  11. Reproducibility of axon reflex-related vasodilation assessed by dynamic thermal imaging in healthy subjects

    NARCIS (Netherlands)

    M.D. Nieuwenhoff (Mariska D.); Wu, Y.; F.J.P.M. Huygen (Frank); A.C. Schouten (A.); F.C.T. van der Helm (Frans C.); S.P. Niehof (Sjoerd)

    2016-01-01

    textabstractIntroduction: Small nerve fiber dysfunction is an early feature of diabetic neuropathy. There is a strong clinical need for a non-invasive method to assess small nerve fiber function. Small nerve fibers mediate axon reflex-related vasodilation and play an important role in thermoregulati

  12. Genetically determined optic neuropathies

    DEFF Research Database (Denmark)

    Milea, Dan; Amati-Bonneau, Patrizia; Reynier, Pascal

    2010-01-01

    The present review focuses on recent advances in the knowledge of hereditary optic neuropathies resulting from retinal ganglion cell degeneration, mostly due to mitochondrial dysfunctions.......The present review focuses on recent advances in the knowledge of hereditary optic neuropathies resulting from retinal ganglion cell degeneration, mostly due to mitochondrial dysfunctions....

  13. HIV Associated Sensory Neuropathy

    OpenAIRE

    G, Amruth; S, Praveen-kumar; B, Nataraju; BS, Nagaraja

    2014-01-01

    Background: In the era of highly active antiretroviral therapy, sensory neuropathies have increased in prevalence. We have documented the frequency and profile of the two most common forms of sensory neuropathies associated with Human Immunodeficiency Virus (HIV) infection and looked into clinicoelectrophysiological correlates to differentiate the two entities.

  14. Propylthiouracil and peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Valentina Van Boekel

    1992-06-01

    Full Text Available 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.

  15. Painful Traumatic Trigeminal Neuropathy.

    Science.gov (United States)

    Rafael, Benoliel; Sorin, Teich; Eli, Eliav

    2016-08-01

    This article discusses neuropathic pain of traumatic origin affecting the trigeminal nerve. This syndrome has been termed painful traumatic trigeminal neuropathy by the International Headache Society and replaces atypical odontalgia, deafferentation pain, traumatic neuropathy, and phantom toothache. The discussion emphasizes the diagnosis and the early and late management of injuries to the trigeminal nerve and subsequent painful conditions.

  16. Nutritional optic neuropathy.

    Science.gov (United States)

    Sawicka-Pierko, Anna; Obuchowska, Iwona; Mariak, Zofia

    2014-01-01

    Nutritional optic neuropathy (aka deficiency optic neuropathy) is a dysfunction of the optic nerve resulting from improper dietary content of certain nutrients essential for normal functioning of the nerve fibers. Most commonly, it results from folic acid and vitamin B complex deficiency associated with malnutrition or poor dietary habits, incorrectly applied vegetarian diet, or chronic alcohol abuse. Obese patients after bariatric surgery constitute another risk group of optic neuropathy. Nutritional optic neuropathy is characterized by painless, gradually progressing, bilateral and symmetrical decrease in visual acuity, which can be accompanied by the color vision dysfunction. Progression of the neuropathy is associated with optic nerve atrophy, manifesting as complete disc pallor. Treatment of nutritional neuropathy includes dietary supplementation, aimed at compensating for the deficient nutrients. The treatment is mostly based on folic acid, vitamin B complex, and protein replacement, as well as eliminating risk factors of neuropathy. Early treatment commencement, prior to irreversible optic nerve atrophy, is a prerequisite of effective treatment. We would like to highlight this problem by presenting the case of a young woman in whom chronic use "water-based" diet resulted in anemia and bilateral nutritional optic neuropathy.

  17. Genetically determined optic neuropathies

    DEFF Research Database (Denmark)

    Milea, Dan; Amati-Bonneau, Patrizia; Reynier, Pascal

    2010-01-01

    The present review focuses on recent advances in the knowledge of hereditary optic neuropathies resulting from retinal ganglion cell degeneration, mostly due to mitochondrial dysfunctions.......The present review focuses on recent advances in the knowledge of hereditary optic neuropathies resulting from retinal ganglion cell degeneration, mostly due to mitochondrial dysfunctions....

  18. Reversible Axonal Dystrophy by Calcium Modulation in Frataxin-Deficient Sensory Neurons of YG8R Mice

    Directory of Open Access Journals (Sweden)

    Belén Mollá

    2017-08-01

    Full Text Available Friedreich’s ataxia (FRDA is a peripheral neuropathy involving a loss of proprioceptive sensory neurons. Studies of biopsies from patients suggest that axonal dysfunction precedes the death of proprioceptive neurons in a dying-back process. We observed that the deficiency of frataxin in sensory neurons of dorsal root ganglia (DRG of the YG8R mouse model causes the formation of axonal spheroids which retain dysfunctional mitochondria, shows alterations in the cytoskeleton and it produces impairment of axonal transport and autophagic flux. The homogenous distribution of axonal spheroids along the neurites supports the existence of continues focal damages. This lead us to propose for FRDA a model of distal axonopathy based on axonal focal damages. In addition, we observed the involvement of oxidative stress and dyshomeostasis of calcium in axonal spheroid formation generating axonal injury as a primary cause of pathophysiology. Axonal spheroids may be a consequence of calcium imbalance, thus we propose the quenching or removal extracellular Ca2+ to prevent spheroids formation. In our neuronal model, treatments with BAPTA and o-phenanthroline reverted the axonal dystrophy and the mitochondrial dysmorphic parameters. These results support the hypothesis that axonal pathology is reversible in FRDA by pharmacological manipulation of intracellular Ca2+ with Ca2+ chelators or metalloprotease inhibitors, preventing Ca2+-mediated axonal injury. Thus, the modulation of Ca2+ levels may be a relevant therapeutic target to develop early axonal protection and prevent dying-back neurodegeneration.

  19. Molecular mechanisms of retinal ganglion cell degeneration in glaucoma and future prospects for cell body and axonal protection

    Science.gov (United States)

    Munemasa, Yasunari; Kitaoka, Yasushi

    2013-01-01

    Glaucoma, which affects more than 70 million people worldwide, is a heterogeneous group of disorders with a resultant common denominator; optic neuropathy, eventually leading to irreversible blindness. The clinical manifestations of primary open-angle glaucoma (POAG), the most common subtype of glaucoma, include excavation of the optic disc and progressive loss of visual field. Axonal degeneration of retinal ganglion cells (RGCs) and apoptotic death of their cell bodies are observed in glaucoma, in which the reduction of intraocular pressure (IOP) is known to slow progression of the disease. A pattern of localized retinal nerve fiber layer (RNFL) defects in glaucoma patients indicates that axonal degeneration may precede RGC body death in this condition. The mechanisms of degeneration of neuronal cell bodies and their axons may differ. In this review, we addressed the molecular mechanisms of cell body death and axonal degeneration in glaucoma and proposed axonal protection in addition to cell body protection. The concept of axonal protection may become a new therapeutic strategy to prevent further axonal degeneration or revive dying axons in patients with preperimetric glaucoma. Further study will be needed to clarify whether the combination therapy of axonal protection and cell body protection will have greater protective effects in early or progressive glaucomatous optic neuropathy (GON). PMID:23316132

  20. Molecular mechanisms of retinal ganglion cell degeneration in glaucoma and future prospects for cell body and axonal protection

    Directory of Open Access Journals (Sweden)

    Yasunari eMunemasa

    2013-01-01

    Full Text Available Glaucoma, which affects more than 70 million people worldwide, is a heterogeneous group of disorders with a resultant common denominator; optic neuropathy, eventually leading to irreversible blindness. The clinical manifestations of primary open-angle glaucoma (POAG, the most common subtype of glaucoma, include excavation of the optic disc and progressive loss of visual field. Axonal degeneration of retinal ganglion cells (RGCs and apoptotic death of their cell bodies are observed in glaucoma, in which the reduction of intraocular pressure is known to slow progression of the disease. A pattern of localized retinal nerve fiber layer defects in glaucoma patients indicates that axonal degeneration may precede RGC body death in this condition. The mechanisms of degeneration of neuronal cell bodies and their axons may differ. In this review, we addressed the molecular mechanisms of cell body death and axonal degeneration in glaucoma and proposed axonal protection in addition to cell body protection. The concept of axonal protection may become a new therapeutic strategy to prevent further axonal degeneration or revive dying axons in patients with preperimetric glaucoma. Further study will be needed to clarify whether the combination therapy of axonal protection and cell body protection will have greater protective effects in early or progressive glaucomatous optic neuropathy.

  1. Axonal bleb recording

    Institute of Scientific and Technical Information of China (English)

    Wenqin Hu; Yousheng Shu

    2012-01-01

    Patch-clamp recording requires direct accessibility of the cell membrane to patch pipettes and allows the investigation of ion channel properties and functions in specific cellular compartments.The cell body and relatively thick dendrites are the most accessible compartments of a neuron,due to their large diameters and therefore great membrane surface areas.However,axons are normally inaccessible to patch pipettes because of their thin structure; thus studies of axon physiology have long been hampered by the lack of axon recording methods.Recently,a new method of patchclamp recording has been developed,enabling direct and tight-seal recording from cortical axons.These recordings are performed at the enlarged structure (axonal bleb) formed at the cut end of an axon after slicing procedures.This method has facilitated studies of the mechanisms underlying the generation and propagation of the main output signal,the action potential,and led to the finding that cortical neurons communicate not only in action potential-mediated digital mode but also in membrane potential-dependent analog mode.

  2. Immunotherapy in Peripheral Neuropathies.

    Science.gov (United States)

    Léger, Jean-Marc; Guimarães-Costa, Raquel; Muntean, Cristina

    2016-01-01

    Immunotherapy has been investigated in a small subset of peripheral neuropathies, including an acute one, Guillain-Barré syndrome, and 3 chronic forms: chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and neuropathy associated with IgM anti-myelin-associated glycoprotein. Several experimental studies and clinical data are strongly suggestive of an immune-mediated pathogenesis. Either cell-mediated mechanisms or antibody responses to Schwann cell, compact myelin, or nodal antigens are considered to act together in an aberrant immune response to cause damage to peripheral nerves. Immunomodulatory treatments used in these neuropathies aim to act at various steps of this pathogenic process. However, there are many phenotypic variants and, consequently, there is a significant difference in the response to immunotherapy between these neuropathies, as well as a need to improve our knowledge and long-term management of chronic forms.

  3. [Immune-mediated neuropathies].

    Science.gov (United States)

    Stoll, G; Reiners, K

    2016-08-01

    The Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are the most common immune-mediated polyneuropathies, which can show variable clinical and electrophysiological manifestations. Rarer immune-mediated neuropathies encompass paraproteinemic neuropathies (PPN), multifocal motor neuropathy (MMN) and vasculitic neuropathies. The diagnosis usually relies on the history of symptom evolution, distribution of nerve dysfunction and particularly on characteristic features in nerve conduction studies, aided by cerebrospinal fluid (CSF) examination and nerve biopsy findings. The therapeutic toolbox encompasses corticosteroids, immunoglobulins and plasmapheresis often accompanied by long-term immunosuppression. It is important to note that immune-mediated neuropathies selectively respond to treatment and contraindications need to be considered. Despite treatment a considerable number of patients suffer from permanent neurological deficits.

  4. Pyridoxine induced neuropathy by subcutaneous administration in dogs.

    Science.gov (United States)

    Chung, Jin-Young; Choi, Jung-Hoon; Hwang, Cheol-Yong; Youn, Hwa-Young

    2008-06-01

    To construct a sensory neuropathy model, excess pyridoxine (150 mg/kg s.i.d.) was injected subcutaneously in dogs over a period of 7 days. During the administrations period, the dogs experienced body weight reduction and proprioceptive loss involving the hindquarters. After pyridoxine administration was completed, electrophysiological recordings showed that the M wave remained at a normal state, but the H-reflex of the treated dogs disappeared at 7 days. The dorsal funiculus of L(4) was disrupted irregularly in the axons and myelin with vacuolation. The dorsal root ganglia of L(4), and sciatic and tibial nerves showed degenerative changes and vacuolation. However, the lateral and ventral funiculi of L(4) showed a normal histopathologic pattern. Although this subcutaneous administration method did not cause systemic toxicity and effectively induced sensory neuropathy, this study confirmed the possibility of producing a pyridoxine-induced sensory neuropathy model in dogs with short-term administration.

  5. Disease mechanisms in hereditary sensory and autonomic neuropathies.

    Science.gov (United States)

    Verpoorten, Nathalie; De Jonghe, Peter; Timmerman, Vincent

    2006-02-01

    Inherited peripheral neuropathies are common monogenically inherited diseases of the peripheral nervous system. In the most common variant, i.e., the hereditary motor and sensory neuropathies, both motor and sensory nerves are affected. In contrast, sensory abnormalities predominate or are exclusively present in hereditary sensory and autonomic neuropathies (HSAN). HSAN are clinically and genetically heterogeneous and are subdivided according to mode of inheritance, age of onset and clinical evolution. In recent years, 6 disease-causing genes have been identified for autosomal dominant and recessive HSAN. However, vesicular transport and axonal trafficking seem important common pathways leading to degeneration of sensory and autonomic neurons. This review discusses the HSAN-related genes and their biological role in the disease mechanisms leading to HSAN.

  6. Pyridoxine-induced toxicity in rats: a stereological quantification of the sensory neuropathy.

    Science.gov (United States)

    Perry, Tracy Ann; Weerasuriya, Ananda; Mouton, Peter R; Holloway, Harold W; Greig, Nigel H

    2004-11-01

    Excess ingestion of pyridoxine (vitamin B6) causes a severe sensory neuropathy in humans. The mechanism of action has not been fully elucidated, and studies of pyridoxine neuropathy in experimental animals have yielded disparate results. Pyridoxine intoxication appears to produce a neuropathy characterized by necrosis of dorsal root ganglion (DRG) sensory neurons and degeneration of peripheral and central sensory projections, with large diameter neurons being particularly affected. The major determinants affecting the severity of the pyridoxine neuropathy appear to be duration and dose of pyridoxine administration, differential neuronal vulnerability, and species susceptibility. The present study used design-based stereological techniques in conjunction with electrophysiological measures to quantify the morphological and physiological changes that occur in the DRG and the distal myelinated axons of the sciatic nerve following pyridoxine intoxication. This combined stereological and electrophysiological method demonstrates a general approach that could be used for assessing the correlation between pathophysiological and functional parameters in animal models of toxic neuropathy.

  7. Etiologic spectrum of biopsy-proven peripheral neuropathies in childhood from a resource-poor setting.

    Science.gov (United States)

    Krishnan, Pramod; Mahadevan, Anita; Bindu, Parayil Sankaran; Chickabasaviah, Yasha T; Taly, Arun B

    2015-05-01

    There are only a few studies describing the etiologic spectrum of biopsy-proven peripheral neuropathies in children. This study reviewed the clinical, electrophysiological, and pathologic profile of 239 children (≤18 years of age) who have undergone nerve biopsy in a tertiary care centre for neurologic disorders and analyzed the etiologic spectrum and utility of nerve biopsy. The clinical profile, neuropathologic findings, and other investigations were combined to infer the final diagnosis. Neuropathy was detected in 199 biopsies; axonal pathology in 43%; demyelination in 41%; mixed pattern in 8%; and nonspecific findings in 8%. The major diagnostic categories included hereditary neuropathies (48%), heredodegenerative and metabolic disorders (27%), and inflammatory neuropathies (12%). Nerve biopsy proved most helpful in diagnosis of demyelinating and inflammatory neuropathies, reiterating its usefulness in specific situations.

  8. Medical management of hereditary optic neuropathies

    Directory of Open Access Journals (Sweden)

    Chiara eLa Morgia

    2014-07-01

    Full Text Available Hereditary optic neuropathies are diseases of the optic nerve. The most common are mitochondrial hereditary optic neuropathies, i.e. the maternally inherited Leber’s Hereditary Optic Neuropathy (LHON and Dominant Optic Atrophy (DOA. They both share a mitochondrial pathogenesis that leads to the selective loss of retinal ganglion cells and axons, in particular of the papillo-macular bundle. Typically, LHON is an acute/subacute loss of central vision associated with impairment of color vision and swelling of retinal nerve fibers followed by optic atrophy. DOA, instead, is characterized by a childhood-onset and slowly progressive loss of central vision, worsening over the years, leading to optic atrophy. The diagnostic workup includes neuro-ophthalmologic evaluation and genetic testing of the three most common mitochondrial DNA mutations affecting complex I (11778/ND4, 3460/ND1 and 14484/ND6 for LHON and sequencing of the nuclear gene OPA1 for DOA. Therapeutic strategies are limited including agents that bypass the complex I defect and exert an antioxidant effect (idebenone. Further strategies are aimed at stimulating compensatory mitochondrial biogenesis. Gene therapy is also a promising venue that still needs to be validated.

  9. Medical Management of Hereditary Optic Neuropathies

    Science.gov (United States)

    La Morgia, Chiara; Carbonelli, Michele; Barboni, Piero; Sadun, Alfredo Arrigo; Carelli, Valerio

    2014-01-01

    Hereditary optic neuropathies are diseases affecting the optic nerve. The most common are mitochondrial hereditary optic neuropathies, i.e., the maternally inherited Leber’s hereditary optic neuropathy (LHON) and dominant optic atrophy (DOA). They both share a mitochondrial pathogenesis that leads to the selective loss of retinal ganglion cells and axons, in particular of the papillo-macular bundle. Typically, LHON is characterized by an acute/subacute loss of central vision associated with impairment of color vision and swelling of retinal nerve fibers followed by optic atrophy. DOA, instead, is characterized by a childhood-onset and slowly progressive loss of central vision, worsening over the years, leading to optic atrophy. The diagnostic workup includes neuro-ophthalmologic evaluation and genetic testing of the three most common mitochondrial DNA mutations affecting complex I (11778/ND4, 3460/ND1, and 14484/ND6) for LHON and sequencing of the nuclear gene OPA1 for DOA. Therapeutic strategies are still limited including agents that bypass the complex I defect and exert an antioxidant effect (idebenone). Further strategies are aimed at stimulating compensatory mitochondrial biogenesis. Gene therapy is also a promising avenue that still needs to be validated. PMID:25132831

  10. Inherited peripheral neuropathies due to mitochondrial disorders.

    Science.gov (United States)

    Cassereau, J; Codron, P; Funalot, B

    2014-05-01

    Mitochondrial disorders (MIDs) are frequently responsible for neuropathies with variable severity. Mitochondrial diseases causing peripheral neuropathies (PNP) may be due to mutations of mitochondrial DNA (mtDNA), as is the case in MERRF and MELAS syndromes, or to mutations of nuclear genes. Secondary abnormalities of mtDNA (such as multiple deletions of muscle mtDNA) may result from mitochondrial disorders due to mutations in nuclear genes involved in mtDNA maintenance. This is the case in several syndromes caused by impaired mtDNA maintenance, such as Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO) due to recessive mutations in the POLG gene, which encodes the catalytic subunit of mtDNA polymerase (DNA polymerase gamma), or Mitochondrial Neuro-Gastro-Intestinal Encephalomyopathy (MNGIE), due to recessive mutations in the TYMP gene, which encodes thymidine phosphorylase. The last years have seen a growing list of evidence demonstrating that mitochondrial bioenergetics and dynamics might be dysfunctional in axonal Charcot-Marie-Tooth disease (CMT2), and these mechanisms might present a common link between dissimilar CMT2-causing genes. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  11. Medical management of hereditary optic neuropathies.

    Science.gov (United States)

    La Morgia, Chiara; Carbonelli, Michele; Barboni, Piero; Sadun, Alfredo Arrigo; Carelli, Valerio

    2014-01-01

    Hereditary optic neuropathies are diseases affecting the optic nerve. The most common are mitochondrial hereditary optic neuropathies, i.e., the maternally inherited Leber's hereditary optic neuropathy (LHON) and dominant optic atrophy (DOA). They both share a mitochondrial pathogenesis that leads to the selective loss of retinal ganglion cells and axons, in particular of the papillo-macular bundle. Typically, LHON is characterized by an acute/subacute loss of central vision associated with impairment of color vision and swelling of retinal nerve fibers followed by optic atrophy. DOA, instead, is characterized by a childhood-onset and slowly progressive loss of central vision, worsening over the years, leading to optic atrophy. The diagnostic workup includes neuro-ophthalmologic evaluation and genetic testing of the three most common mitochondrial DNA mutations affecting complex I (11778/ND4, 3460/ND1, and 14484/ND6) for LHON and sequencing of the nuclear gene OPA1 for DOA. Therapeutic strategies are still limited including agents that bypass the complex I defect and exert an antioxidant effect (idebenone). Further strategies are aimed at stimulating compensatory mitochondrial biogenesis. Gene therapy is also a promising avenue that still needs to be validated.

  12. [Hereditary optic neuropathies].

    Science.gov (United States)

    Milea, D; Verny, C

    2012-10-01

    Hereditary optic neuropathies are a group of heterogeneous conditions affecting both optic nerves, with an autosomal dominant, autosomal recessive, X-related or mitochondrial transmission. The two most common non-syndromic hereditary optic neuropathies (Leber's hereditary optic neuropathy and autosomal dominant optic atrophy) are very different in their clinical presentation and their genetic transmission, leading however to a common, non-specific optic nerve atrophy. Beyond the optic atrophy-related visual loss, which is the clinical hallmark of this group of diseases, other associated neurological signs are increasingly recognized.

  13. Genes for Hereditary Sensory and Autonomic Neuropathies: A Genotype-Phenotype Correlation

    Science.gov (United States)

    Rotthier, Annelies; Baets, Jonathan; De Vriendt, Els; Jacobs, An; Auer-Grumbach, Michaela; Levy, Nicolas; Bonello-Palot, Nathalie; Kilic, Sara Sebnem; Weis, Joachim; Nascimento, Andres; Swinkels, Marielle; Kruyt, Moyo C.; Jordanova, Albena; De Jonghe, Peter; Timmerman, Vincent

    2009-01-01

    Hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders characterized by axonal atrophy and degeneration, exclusively or predominantly affecting the sensory and autonomic neurons. So far, disease-associated mutations have been identified in seven genes: two genes for autosomal dominant ("SPTLC1"…

  14. Genes for Hereditary Sensory and Autonomic Neuropathies: A Genotype-Phenotype Correlation

    Science.gov (United States)

    Rotthier, Annelies; Baets, Jonathan; De Vriendt, Els; Jacobs, An; Auer-Grumbach, Michaela; Levy, Nicolas; Bonello-Palot, Nathalie; Kilic, Sara Sebnem; Weis, Joachim; Nascimento, Andres; Swinkels, Marielle; Kruyt, Moyo C.; Jordanova, Albena; De Jonghe, Peter; Timmerman, Vincent

    2009-01-01

    Hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders characterized by axonal atrophy and degeneration, exclusively or predominantly affecting the sensory and autonomic neurons. So far, disease-associated mutations have been identified in seven genes: two genes for autosomal dominant ("SPTLC1"…

  15. Nerve Damage (Diabetic Neuropathies)

    Science.gov (United States)

    ... normally. A woman may have difficulty with arousal, lubrication, or orgasm. Sweat Glands Autonomic neuropathy can affect ... performed in people with diabetes. Comprehensive foot care programs can reduce amputation rates by 45 to 85 ...

  16. Clinical and electrophysiological characteristics of neuropathy associated with Tangier disease.

    Science.gov (United States)

    Zyss, Julie; Béhin, Anthony; Couvert, Philippe; Bouhour, Françoise; Sassolas, Agnès; Kolev, Ivan; Denys, Violaine; Vial, Christophe; Lacour, A; Carrié, Alain; Stojkovic, Tanya

    2012-06-01

    Tangier disease (TD) (OMIM#205400) is a rare autosomal recessive disorder resulting from mutations in the ABCA1 gene, leading to decreased levels of plasma high-density lipoproteins (HDL). Peripheral neuropathy is a common finding in this disease, and may present as relapsing/remitting mono/polyneuropathies or as syringomyelia-like neuropathy. We retrospectively analyzed four patients, and report here their clinical, biological, electrophysiological, imaging, and genetic findings. Three patients had a typical pseudosyringomyelic neuropathy including facial diplegia, but asymmetrical onset was observed in one patient who had first been misdiagnosed with Lewis-Sumner syndrome. Electrophysiological pattern was heterogeneous, showing both signs of demyelination and axonal degeneration. Truncating mutations of the ABCA1 gene, including two previously undescribed mutations, were constantly found. Atypical symptom onset and demyelinating features on electrophysiological examination can be misleading in case of pseudosyringomyelic neuropathy. These reports illustrate two different neurological phenotypes in TD, namely the pseudosyringomyelic type and the Lewis-Sumner-like type, and advocate for a systematic assessment of lipid profile including HDL cholesterol in demyelinating neuropathies.

  17. Neuropathy in multiple myeloma treated with thalidomide: a prospective study.

    Science.gov (United States)

    Plasmati, R; Pastorelli, F; Cavo, M; Petracci, E; Zamagni, E; Tosi, P; Cangini, D; Tacchetti, P; Salvi, F; Bartolomei, I; Michelucci, R; Tassinari, C A

    2007-08-07

    Thalidomide is effective as a first-line therapy for the treatment of multiple myeloma (MM), but its use is limited by peripheral neurotoxicity. To study the occurrence of both myeloma-related neuropathy and thalidomide-induced neuropathy in 31 patients with newly diagnosed MM. Clinical and electrophysiologic examinations were performed in 31 patients with newly diagnosed MM before and after 4 months of therapy with thalidomide (200 mg/day, total dose: 21 g) aimed at debulking MM, before autologous transplantation. After transplantation, the patients took thalidomide, 200 mg/day for another 3 months (total dose over three months: 18 g) and then underwent a final clinical and electrophysiologic checkup. At baseline, four patients presented a mild sensorimotor peripheral neuropathy related to MM, which tended to worsen slightly during treatment with thalidomide. At the end of treatment, 83% of the patients had clinical and electrophysiologic evidence of a mild sensory rather than motor, axonal, length-dependent polyneuropathy, whereas 100% of the patients showed improvement to the basic pathology (>or=partial response). Peripheral neuropathy, sometimes subclinical, and mild in our patients, is a common, early side effect of thalidomide therapy. The high doses (21 g) used in all patients for a relatively short time (4 months) rule out any correlations between neuropathy, total dose, and duration of treatment.

  18. Diabetic neuropathy in children.

    Science.gov (United States)

    Mah, Jean K; Pacaud, Danièle

    2014-01-01

    The worldwide burden of diabetes and its complications in children continues to increase due to the rise in type 1 and type 2 diabetes. Although overt diabetic neuropathy is rarely present in children and adolescents with diabetes, subclinical diabetic neuropathy has been estimated to occur in approximately half of all children with type 1 diabetes with a duration of 5 years or longer and up to 25% of pediatric patients with newly diagnosed diabetes have abnormal findings on nerve conduction studies. The present review on the state of pediatric diabetic neuropathy covers the definition, prevalence, pathogenesis, diagnosis, risk factors, and possible treatment approaches specific to children and adolescents with diabetes. It also highlights the many unknowns in this field. Nonetheless, new emerging interventions that can either prevent or delay the progression of diabetic microvascular and macrovascular complications may become available in the near future. Until specific interventions for diabetic neuropathy are available for use in children, it will be hard to justify screening for neuropathy other than through clinical assessment. Meanwhile, the search for quicker, easily administered, and quantifiable tests for diabetic neuropathy and efforts to establish valid pediatric norms for well-established measures used in adults will need to continue.

  19. Glia to axon RNA transfer.

    Science.gov (United States)

    Sotelo, José Roberto; Canclini, Lucía; Kun, Alejandra; Sotelo-Silveira, José Roberto; Calliari, Aldo; Cal, Karina; Bresque, Mariana; Dipaolo, Andrés; Farias, Joaquina; Mercer, John A

    2014-03-01

    The existence of RNA in axons has been a matter of dispute for decades. Evidence for RNA and ribosomes has now accumulated to a point at which it is difficult to question, much of the disputes turned to the origin of these axonal RNAs. In this review, we focus on studies addressing the origin of axonal RNAs and ribosomes. The neuronal soma as the source of most axonal RNAs has been demonstrated and is indisputable. However, the surrounding glial cells may be a supplemental source of axonal RNAs, a matter scarcely investigated in the literature. Here, we review the few papers that have demonstrated that glial-to-axon RNA transfer is not only feasible, but likely. We describe this process in both invertebrate axons and vertebrate axons. Schwann cell to axon ribosomes transfer was conclusively demonstrated (Court et al. [2008]: J. Neurosci 28:11024-11029; Court et al. [2011]: Glia 59:1529-1539). However, mRNA transfer still remains to be demonstrated in a conclusive way. The intercellular transport of mRNA has interesting implications, particularly with respect to the integration of glial and axonal function. This evolving field is likely to impact our understanding of the cell biology of the axon in both normal and pathological conditions. Most importantly, if the synthesis of proteins in the axon can be controlled by interacting glia, the possibilities for clinical interventions in injury and neurodegeneration are greatly increased.

  20. Peripheral neuropathies in Sjögren's syndrome: a critical update on clinical features and pathogenetic mechanisms.

    Science.gov (United States)

    Pavlakis, P P; Alexopoulos, H; Kosmidis, M L; Mamali, I; Moutsopoulos, H M; Tzioufas, A G; Dalakas, M C

    2012-08-01

    Sjögren's syndrome is a systemic autoimmune disease that, apart from exocrine glands, may affect every organ or system. Involvement of different sections of the peripheral nervous system results in a wide spectrum of neuropathic manifestations. Based on distinct clinical, electrophysiological and histological criteria, the types of neuropathies seen in Sjögren's syndrome include: a) pure sensory which presents with distal symmetric sensory loss due to axonal degeneration of sensory fibers; sensory ataxia due to loss of proprioceptive large fibers (ganglionopathy); or with painful dysethesias (small fiber sensory neuropathy) due to degeneration of cutaneous axons. The latter appears to be the most common neuropathy in Sjögren's syndrome and requires skin biopsy for diagnosis to document loss or reduction of nerve fiber density; b) sensorimotor polyneuropathy affecting sensory and motor axons, often associated with severe systemic or pro-lymhomatous manifestations, such as palpable purpura and cryoglobulinemia, and c) rare types that include autoimmune demyelinating neuropathy, mononeuropathy, mononeuropathy multiplex and autonomic neuropathy. In this review, the frequency, prevalence and diagnostic criteria for each neuropathy subset are discussed and possible pathogenetic mechanisms are outlined.

  1. Evidence of GLP-1-mediated neuroprotection in an animal model of pyridoxine-induced peripheral sensory neuropathy

    OpenAIRE

    2006-01-01

    Pyridoxine (vitamin B6) intoxicated rodents develop a peripheral neuropathy characterized by sensory nerve conduction deficits associated with disturbances of nerve fiber geometry and axonal atrophy. To investigate the possibility that glucagon-like peptide-1 (7-36)-amide (GLP-1) receptor agonism may influence axonal structure and function through neuroprotection neurotrophic support, effects of GLP-1 and its long acting analog, Exendin-4 (Ex4) treatment on pyridoxine-induced peripheral neuro...

  2. The mitochondrial connection in auditory neuropathy.

    Science.gov (United States)

    Cacace, Anthony T; Pinheiro, Joaquim M B

    2011-01-01

    'Auditory neuropathy' (AN), the term used to codify a primary degeneration of the auditory nerve, can be linked directly or indirectly to mitochondrial dysfunction. These observations are based on the expression of AN in known mitochondrial-based neurological diseases (Friedreich's ataxia, Mohr-Tranebjærg syndrome), in conditions where defects in axonal transport, protein trafficking, and fusion processes perturb and/or disrupt mitochondrial dynamics (Charcot-Marie-Tooth disease, autosomal dominant optic atrophy), in a common neonatal condition known to be toxic to mitochondria (hyperbilirubinemia), and where respiratory chain deficiencies produce reductions in oxidative phosphorylation that adversely affect peripheral auditory mechanisms. This body of evidence is solidified by data derived from temporal bone and genetic studies, biochemical, molecular biologic, behavioral, electroacoustic, and electrophysiological investigations.

  3. Pyridoxine-induced sensory ataxic neuronopathy and neuropathy: revisited.

    Science.gov (United States)

    Kulkantrakorn, Kongkiat

    2014-11-01

    High dose pyridoxine is neurotoxic. Previous case reports were sparse and little is known about the clinical and electrodiagnostic findings. Three patients with pyridoxine-induced sensory ataxic neuropathy were studied and a review of the involved literature was performed. Three patients, aged 80, 83 and 83 years old, presented with sensory ataxia for 3-8 months. Examination showed signs of polyneuropathy and sensory ataxia. Six hundred milligrams of pyridoxine was consumed each day for 3-10 years, in the form of vitamin B1-6-12 combination tablet. Investigations for other causes of neuropathy were unremarkable. Blood levels of vitamin B6 were markedly elevated at 104.6, 81.4 and 66.9 times of upper normal limits. Electrodiagnostic tests showed symmetric axonal sensory polyneuropathy in two patients. Two years after vitamin discontinuation, all patients showed no significant improvement in the neuropathy and gait. In conclusion, consumption of high dose pyridoxine can cause sensory neuronopathy and axonal sensorimotor polyneuropathy, leading to sensory ataxia which may not be reversible.

  4. Current issues in peripheral neuropathy.

    Science.gov (United States)

    Brannagan, Thomas H

    2012-05-01

    Twenty million people in the United States are estimated to have peripheral neuropathy. However, many patients are not aware of their diagnosis, are not given the diagnosis or being treated, or the diagnosis is delayed. Currently, the only treatments available for neuropathy are aimed at treating the underlying medical conditions that cause the neuropathy or treating symptoms such as pain. Neither treats the actual nerve fiber dysfunction or fiber loss, or helps nerve fibers regenerate. Idiopathic neuropathy, that is neuropathy for which a cause is not identified, is common, accounting in referral series for 25% in all neuropathy patients and 50% or more of patients with small fiber neuropathy. Currently, there is only one FDA-approved medication for a specific neuropathy (chronic inflammatory demyelinating polyneuropathy) while there are two FDA approved medications for diabetic neuropathy pain and four that are approved for post-herpetic neuralgia pain. For many patients with painful neuropathy, these medications are ineffective or not tolerated. Continued research into the underlying mechanisms of neuropathy and an increased understanding of nerve regeneration and neuropathic pain are needed to address this unmet medical need among patients with neuropathy.

  5. Entrapment neuropathies in sports medicine

    OpenAIRE

    2001-01-01

    The more frequent entrapment neuropathies related to sport are described: thoracic outlet syndrome in aquatic athletes and pitchers, long thoracic neuropathy in tennis players, suprascapular neuropathy in volleyball and tennis players, ulnar nerve entrapment at the elbow in pitchers and at the wrist in cyclists, Morton's syndrome in runners and dancers. Peer reviewed

  6. Diabetic neuropathies: diagnosis and management.

    Science.gov (United States)

    Deli, Gabriella; Bosnyak, Edit; Pusch, Gabriella; Komoly, Samuel; Feher, Gergely

    2013-01-01

    Changes in human behaviour and lifestyle over the last century have resulted in a dramatic increase in the incidence of diabetes worldwide. Neuropathy is a common and costly complication of both type 1 and type 2 diabetes. The prevalence of neuropathy is estimated to be about 8% in newly diagnosed patients and greater than 50% in patients with long-standing disease. There are two main types of diabetic neuropathies, named as sensorimotor and autonomic neuropathies. Sensorimotor neuropathy is marked by pain, paraesthesia and sensory loss, and autonomic neuropathy may contribute to myocardial infarction, malignant arrhythmia and sudden death. In this article we reviewed the pathogenesis, clinical manifestations diagnosis and treatment of diabetic neuropathies. Sensorimotor and autonomic neuropathies (cardiovascular, gastrointestinal and genitourinary autonomic neuropathies) are common in diabetic patients. Apart from strict glycaemic control, no further therapeutic approach exists in the prevention of this phenomenon. Intensive diabetes therapy, intensive multifactorial cardiovascular risk reduction and lifestyle intervention are recommended in patients with cardiovascular autonomic neuropathy. Gastroparesis is the most debilitating complication of gastrointestinal autonomic neuropathy and genitourinary autonomic neuropathy can cause sexual dysfunction and neurogenic bladder; these conditions are hard to manage. The symptomatic treatment of sensory symptoms includes tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors, gabapentin, pregabalin and opioids. Other treatment strategies are not so effective. © 2013 S. Karger AG, Basel.

  7. Functional deficits in peripheral nerve mitochondria in rats with paclitaxel- and oxaliplatin-evoked painful peripheral neuropathy.

    Science.gov (United States)

    Zheng, Huaien; Xiao, Wen Hua; Bennett, Gary J

    2011-12-01

    Cancer chemotherapeutics like paclitaxel and oxaliplatin produce a dose-limiting chronic sensory peripheral neuropathy that is often accompanied by neuropathic pain. The cause of the neuropathy and pain is unknown. In animal models, paclitaxel-evoked and oxaliplatin-evoked painful peripheral neuropathies are accompanied by an increase in the incidence of swollen and vacuolated mitochondria in peripheral nerve axons. It has been proposed that mitochondrial swelling and vacuolation are indicative of a functional impairment and that this results in a chronic axonal energy deficiency that is the cause of the neuropathy's symptoms. However, the significance of mitochondrial swelling and vacuolation is ambiguous and a test of the hypothesis requires a direct assessment of the effects of chemotherapy on mitochondrial function. The results of such an assessment are reported here. Mitochondrial respiration and ATP production were measured in rat sciatic nerve samples taken 1-2 days after and 3-4 weeks after induction of painful peripheral neuropathy with paclitaxel and oxaliplatin. Significant deficits in Complex I-mediated and Complex II-mediated respiration and significant deficits in ATP production were found for both drugs at both time points. In addition, prophylactic treatment with acetyl-l-carnitine, which inhibited the development of paclitaxel-evoked and oxaliplatin-evoked neuropathy, prevented the deficits in mitochondrial function. These results implicate mitotoxicity as a possible cause of chemotherapy-evoked chronic sensory peripheral neuropathy.

  8. Hypertension-induced peripheral neuropathy and the combined effects of hypertension and diabetes on nerve structure and function in rats.

    Science.gov (United States)

    Gregory, Joshua A; Jolivalt, Corinne G; Goor, Jared; Mizisin, Andrew P; Calcutt, Nigel A

    2012-10-01

    Diabetic neuropathy includes damage to neurons, Schwann cells and blood vessels. Rodent models of diabetes do not adequately replicate all pathological features of diabetic neuropathy, particularly Schwann cell damage. We, therefore, tested the hypothesis that combining hypertension, a risk factor for neuropathy in diabetic patients, with insulin-deficient diabetes produces a more pertinent model of peripheral neuropathy. Behavioral, physiological and structural indices of neuropathy were measured for up to 6 months in spontaneously hypertensive and age-matched normotensive rats with or without concurrent streptozotocin-induced diabetes. Hypertensive rats developed nerve ischemia, thermal hyperalgesia, nerve conduction slowing and axonal atrophy. Thinly myelinated fibers with supernumerary Schwann cells indicative of cycles of demyelination and remyelination were also identified along with reduced nerve levels of myelin basic protein. Similar disorders were noted in streptozotocin-diabetic rats, except that thinly myelinated fibers were not observed and expression of myelin basic protein was normal. Superimposing diabetes on hypertension compounded disorders of nerve blood flow, conduction slowing and axonal atrophy and increased the incidence of thinly myelinated fibers. Rats with combined insulinopenia, hyperglycemia and hypertension provide a model for diabetic neuropathy that offers an opportunity to study mechanisms of Schwann cell pathology and suggests that hypertension may contribute to the etiology of diabetic neuropathy.

  9. Docetaxel-induced neuropathy

    DEFF Research Database (Denmark)

    Eckhoff, Lise; Feddersen, Søren; Knoop, Ann

    2015-01-01

    Background. Docetaxel is a highly effective treatment of a wide range of malignancies but is often associated with peripheral neuropathy. The genetic variability of genes involved in the transportation or metabolism of docetaxel may be responsible for the variation in docetaxel-induced peripheral...... neuropathy (DIPN). The main purpose of this study was to investigate the impact of genetic variants in GSTP1 and ABCB1 on DIPN. Material and methods. DNA was extracted from whole blood from 150 patients with early-stage breast cancer who had received adjuvant docetaxel from February 2011 to May 2012. Two...

  10. Loss of function mutations in HARS cause a spectrum of inherited peripheral neuropathies.

    Science.gov (United States)

    Safka Brozkova, Dana; Deconinck, Tine; Griffin, Laurie Beth; Ferbert, Andreas; Haberlova, Jana; Mazanec, Radim; Lassuthova, Petra; Roth, Christian; Pilunthanakul, Thanita; Rautenstrauss, Bernd; Janecke, Andreas R; Zavadakova, Petra; Chrast, Roman; Rivolta, Carlo; Zuchner, Stephan; Antonellis, Anthony; Beg, Asim A; De Jonghe, Peter; Senderek, Jan; Seeman, Pavel; Baets, Jonathan

    2015-08-01

    Inherited peripheral neuropathies are a genetically heterogeneous group of disorders characterized by distal muscle weakness and sensory loss. Mutations in genes encoding aminoacyl-tRNA synthetases have been implicated in peripheral neuropathies, suggesting that these tRNA charging enzymes are uniquely important for the peripheral nerve. Recently, a mutation in histidyl-tRNA synthetase (HARS) was identified in a single patient with a late-onset, sensory-predominant peripheral neuropathy; however, the genetic evidence was lacking, making the significance of the finding unclear. Here, we present clinical, genetic, and functional data that implicate HARS mutations in inherited peripheral neuropathies. The associated phenotypic spectrum is broad and encompasses axonal and demyelinating motor and sensory neuropathies, including four young patients presenting with pure motor axonal neuropathy. Genome-wide linkage studies in combination with whole-exome and conventional sequencing revealed four distinct and previously unreported heterozygous HARS mutations segregating with autosomal dominant peripheral neuropathy in four unrelated families (p.Thr132Ile, p.Pro134His, p.Asp175Glu and p.Asp364Tyr). All mutations cause a loss of function in yeast complementation assays, and p.Asp364Tyr is dominantly neurotoxic in a Caenorhabditis elegans model. This study demonstrates the role of HARS mutations in peripheral neuropathy and expands the genetic and clinical spectrum of aminoacyl-tRNA synthetase-related human disease. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Mechanisms of diabetic neuropathy: Schwann cells.

    Science.gov (United States)

    Mizisin, Andrew P

    2014-01-01

    As ensheathing and secretory cells, Schwann cells are a ubiquitous and vital component of the endoneurial microenvironment of peripheral nerves. The interdependence of axons and their ensheathing Schwann cells predisposes each to the impact of injury in the other. Further, the dependence of the blood-nerve interface on trophic support from Schwann cells during development, adulthood, and after injury suggests these glial cells promote the structural and functional integrity of nerve trunks. Here, the developmental origin, injury-induced changes, and mature myelinating and nonmyelinating phenotypes of Schwann cells are reviewed prior to a description of nerve fiber pathology and consideration of pathogenic mechanisms in human and experimental diabetic neuropathy. A fundamental role for aldose-reductase-containing Schwann cells in the pathogenesis of diabetic neuropathy, as well as the interrelationship of pathogenic mechanisms, is indicated by the sensitivity of hyperglycemia-induced biochemical alterations, such as polyol pathway flux, formation of reactive oxygen species, generation of advanced glycosylation end products (AGEs) and deficient neurotrophic support, to blocking polyol pathway flux.

  12. Painful neuropathies: the emerging role of sodium channelopathies.

    Science.gov (United States)

    Brouwer, Brigitte A; Merkies, Ingemar S J; Gerrits, Monique M; Waxman, Stephen G; Hoeijmakers, Janneke G J; Faber, Catharina G

    2014-06-01

    Pain is a frequent debilitating feature reported in peripheral neuropathies with involvement of small nerve (Aδ and C) fibers. Voltage-gated sodium channels are responsible for the generation and conduction of action potentials in the peripheral nociceptive neuronal pathway where NaV 1.7, NaV 1.8, and NaV 1.9 sodium channels (encoded by SCN9A, SCN10A, and SCN11A) are preferentially expressed. The human genetic pain conditions inherited erythromelalgia and paroxysmal extreme pain disorder were the first to be linked to gain-of-function SCN9A mutations. Recent studies have expanded this spectrum with gain-of-function SCN9A mutations in patients with small fiber neuropathy and in a new syndrome of pain, dysautonomia, and small hands and small feet (acromesomelia). In addition, painful neuropathies have been recently linked to SCN10A mutations. Patch-clamp studies have shown that the effect of SCN9A mutations is dependent upon the cell-type background. The functional effects of a mutation in dorsal root ganglion (DRG) neurons and sympathetic neuron cells may differ per mutation, reflecting the pattern of expression of autonomic symptoms in patients with painful neuropathies who carry the mutation in question. Peripheral neuropathies may not always be length-dependent, as demonstrated in patients with initial facial and scalp pain symptoms with SCN9A mutations showing hyperexcitability in both trigeminal ganglion and DRG neurons. There is some evidence suggesting that gain-of-function SCN9A mutations can lead to degeneration of peripheral axons. This review will focus on the emerging role of sodium channelopathies in painful peripheral neuropathies, which could serve as a basis for novel therapeutic strategies.

  13. Depletion of Mitofusin-2 Causes Mitochondrial Damage in Cisplatin-Induced Neuropathy.

    Science.gov (United States)

    Bobylev, Ilja; Joshi, Abhijeet R; Barham, Mohammed; Neiss, Wolfram F; Lehmann, Helmar C

    2017-01-21

    Sensory neuropathy is a relevant side effect of the antineoplastic agent cisplatin. Mitochondrial damage is assumed to play a critical role in cisplatin-induced peripheral neuropathy, but the pathomechanisms underlying cisplatin-induced mitotoxicity and neurodegeneration are incompletely understood. In an animal model of cisplatin-induced neuropathy, we determined in detail the extent and spatial distribution of mitochondrial damage during cisplatin treatment. Changes in the total number of axonal mitochondria during cisplatin treatment were assessed in intercostal nerves from transgenic mice that express cyan fluorescent protein. Further, we explored the impact of cisplatin on the expression of nuclear encoded molecules of mitochondrial fusion and fission, including mitofusin-2 (MFN2), optic atrophy 1 (OPA1), and dynamin-related protein 1 (DRP1). Cisplatin treatment resulted in a loss of total mitochondrial mass in axons and in an abnormal mitochondrial morphology including atypical enlargement, increased vacuolization, and loss of cristae. These changes were observed in distal and proximal nerve segments and were more prominent in axons than in Schwann cells. Transcripts of fusion and fission proteins were reduced in distal nerve segments. Significant reduced expression levels of the fusion protein MFN2 was detected in nerves of cisplatin-exposed animals. In summary, we provide for the first time an evidence that cisplatin alters mitochondrial dynamics in peripheral nerves. Loss of MFN2, previously implicated in the pathogenesis of other neurodegenerative diseases, also contributes to the pathogenesis in cisplatin-induced neuropathy.

  14. Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy.

    Science.gov (United States)

    Chance, Phillip F

    2006-01-01

    Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or "sausage-like" formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often

  15. HANSENS DISEASE : STUDY OF CLINICAL, NEUROPATHOLOGICAL, NEUROPHYSIOLOGICAL PATTERN OF LEPROUS NEUROPATHY

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2015-07-01

    Full Text Available A need still exists to determine the clinical and neurophysiological characteristics of leprosy neuropathy at distinct times of the disease by different methods that measure the various nerve fiber functions. A prospective clinical study was performed 100 patients of clinically proven Hansen’s will take in study and given diagnosis is made by dermatologist and neurologist. For Study of Clinical, Neuropathological , Neurophysiological Pattern of leprous neuropathy and results shows that Peripheral neuropath y is common neurological disorder, although population based studies are scarce. It is a diverse group of disorder with varying etiologies. Many of these are amenable to treatment while others are not. It affects all age groups are different etiologies in various age groups. Disorder is more common in males. Leprosy is still most common cause of peripheral neuropathy in this part of world. GBS is commonest cause in acutely presenting patients of peripheral neuropathy. Vacuities is also common especially in undiagnosed peripheral neuropathy patients and revealed by nerve biopsy. Tingling and numbness are two most common sensory complains. On objective sensory examination impairment of pain/temperature was most common. Evidence of large fiber dysfunction was less common. Almost half of leprous neuropathy had impaired joint position and vibration. Anesthetic patches and thickened nerve are two commonest indicators of leprous neuropathy. Among DTRs ankle jerk was most commonly affected. Almost half of GBS patie nts had history of preceding illness. Overall sensorimotor polyneuropathy was most common type of pattern after clinical - electrophysiological evaluation. Multiple mononeuropathy was most common in leprous neuropathy. Most patients had axonal type of invo lvement. In GBS patients predominantly motor neuropathy was found Skin smear examination is readily available and easy test to diagnosed leprosy, if done carefully. Sural nerve biopsy

  16. [Pathophysiology of sensory ataxic neuropathy].

    Science.gov (United States)

    Sobue, G

    1996-12-01

    The main lesions of sensory ataxic neuropathy such as chronic idiopathic sensory ataxic neuropathy, (ISAN), carcinomatous neuropathy, Sjögren syndrome-associated neuropathy and acute autonomic and sensory neuropathy (AASN) are the large-diameter sensory neurons and dosal column of the spinal cord and the large myelinated fibers in the peripheral nerve trunks. In addition, afferent fibers to the Clarke's nuclei are also severely involved, suggesting Ia fibers being involved in these neuropathies. In NT-3 knockout mouse, an animal model of sensory ataxia, large-sized la neurons as well as muscle spindle and Golgi tendon organs are depleted, and are causative for sensory ataxia. Thus, the proprioceptive Ia neurons would play a role in pathogenesis of sensory ataxia in human sensory ataxic neuropathies, but the significance of dorsal column involvement in human sensory ataxia is still needed to evaluate.

  17. Recurrence Quantification Analysis of F-Waves and the Evaluation of Neuropathies

    Directory of Open Access Journals (Sweden)

    Morris A. Fisher

    2015-01-01

    Full Text Available Electrodiagnostic (EDX patterns of neuropathic dysfunction have been based on axonal/demyelinating criteria requiring prior assumptions. This has not produced classifications of desired sensitivity or specificity. Furthermore, standard nerve conduction studies have limited reproducibility. New methodologies in EDX seem important. Recurrent Quantification Analysis (RQA is a nonlinear method for examining patterns of recurrence. RQA might provide a unique method for the EDX evaluation of neuropathies. RQA was used to analyze F-wave recordings from the abductor hallucis muscle in 61 patients with neuropathies. Twenty-nine of these patients had diabetes as the sole cause of their neuropathies. In the other 32 patients, the etiologies of the neuropathies were diverse. Commonly used EDX variables were also recorded. RQA data could separate the 29 patients with diabetic neuropathies from the other 32 patients (P<0.009. Statistically significant differences in two EDX variables were also present: compound muscle action potential amplitudes (P<0.007 and F-wave persistence (P<0.001. RQA analysis of F-waves seemed able to distinguish diabetic neuropathies from the other neuropathies studied, and this separation was associated with specific physiological abnormalities. This study would therefore support the idea that RQA of F-waves can distinguish between types of neuropathic dysfunction based on EDX data alone without prior assumptions.

  18. Recurrence Quantification Analysis of F-Waves and the Evaluation of Neuropathies.

    Science.gov (United States)

    Fisher, Morris A; Patil, Vijaya K; Webber, Charles L

    2015-01-01

    Electrodiagnostic (EDX) patterns of neuropathic dysfunction have been based on axonal/demyelinating criteria requiring prior assumptions. This has not produced classifications of desired sensitivity or specificity. Furthermore, standard nerve conduction studies have limited reproducibility. New methodologies in EDX seem important. Recurrent Quantification Analysis (RQA) is a nonlinear method for examining patterns of recurrence. RQA might provide a unique method for the EDX evaluation of neuropathies. RQA was used to analyze F-wave recordings from the abductor hallucis muscle in 61 patients with neuropathies. Twenty-nine of these patients had diabetes as the sole cause of their neuropathies. In the other 32 patients, the etiologies of the neuropathies were diverse. Commonly used EDX variables were also recorded. RQA data could separate the 29 patients with diabetic neuropathies from the other 32 patients (P neuropathies from the other neuropathies studied, and this separation was associated with specific physiological abnormalities. This study would therefore support the idea that RQA of F-waves can distinguish between types of neuropathic dysfunction based on EDX data alone without prior assumptions.

  19. Diagnostic value of sonography in treatment-naive chronic inflammatory neuropathies.

    Science.gov (United States)

    Goedee, H Stephan; van der Pol, W Ludo; van Asseldonk, Jan-Thies H; Franssen, Hessel; Notermans, Nicolette C; Vrancken, Alexander J F E; van Es, Michael A; Nikolakopoulos, Stavros; Visser, Leo H; van den Berg, Leonard H

    2017-01-10

    To determine the diagnostic value of high-resolution ultrasound (HRUS) for detection of chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis-Sumner syndrome (LSS), and multifocal motor neuropathy (MMN). Between January 2013 and January 2015, we enrolled 75 consecutive treatment-naive patients with chronic inflammatory neuropathies and 70 disease controls. We performed extensive nerve conduction and standardized HRUS studies bilaterally of large arm and leg nerves and brachial plexus. We determined optimal sonographic cutoff values of nerve size and used receiver operating characteristic analysis and logistic regression models to identify nerve combinations with optimal diagnostic performance. Enlargement of median nerve at forearm >10 mm(2), upper arm >13 mm(2), and any trunk of brachial plexus >8 mm(2) was 99% specific for chronic inflammatory neuropathies. A shortened HRUS protocol for detecting this abnormal nerve enlargement showed high sensitivity (83%-95%), positive predictive value (100%), and negative predictive value (98%) in discriminating CIDP, LSS, and MMN from clinical mimics. Sonographic enlargement of proximal median nerve segments in the arms and brachial plexus is a key feature of chronic inflammatory neuropathies, which helps to reliably distinguish them from axonal neuropathies and amyotrophic lateral sclerosis. This study provides Class II evidence that, in absence of clinical features that suggest a hereditary demyelinating neuropathy, sonographic enlargement of proximal median nerve segments and brachial plexus accurately identifies patients with chronic inflammatory neuropathies. © 2016 American Academy of Neurology.

  20. Experimental therapeutics in hereditary neuropathies: the past, the present, and the future.

    Science.gov (United States)

    Herrmann, David N

    2008-10-01

    Hereditary neuropathies represent approximately 40% of undiagnosed neuropathies in a tertiary clinic setting. The Charcot-Marie-Tooth neuropathies (CMT) are the most common. Mutations in more than 40 genes have been identified to date in CMT. Approximately 50% of CMT cases are accounted for by CMT type 1A, due to a duplication within the peripheral myelin protein 22 gene (PMP22). Mutations in the gap junction beta 1 gene (GJB1), the myelin protein zero gene (MPZ), and the mitofusin 2 gene (MFN2) account for a substantial proportion of other genetically definable CMT. Some 15% of demyelinating CMT and 70% of axonal CMT await genetic clarification. Other hereditary neuropathies include the hereditary sensory and autonomic neuropathies, the familial amyloid polyneuropathies, and multisystem disorders (e.g., lipid storage diseases and inherited ataxias) that have peripheral neuropathy as a major or minor component. This review surveys the challenges of developing effective therapies for hereditary neuropathies in terms of past, present, and future experimental therapeutics in CMT.

  1. Microfluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Black, Bryan; Ordonez, Simon; Mondal, Argha; Jain, Ankur; Mohanty, Samarendra

    2014-10-01

    The precision of axonal pathfinding and the accurate formation of functional neural circuitry are crucial for an organism during development as well as during adult central and peripheral nerve regeneration. While chemical cues are believed to be primarily responsible for axonal pathfinding, we hypothesize that forces due to localized fluid flow may directly affect neuronal guidance during early organ development. Here, we report direct evidence of fluid flow influencing axonal migration, producing turning angles of up to 90°. Microfluidic flow simulations indicate that an axon may experience significant bending force due to cross-flow, which may contribute to the observed axonal turning. This method of flow-based guidance was successfully used to fasciculate one advancing axon onto another, showcasing the potential of this technique to be used for the formation of in vitro neuronal circuits.

  2. Blocking mitochondrial calcium release in Schwann cells prevents demyelinating neuropathies.

    Science.gov (United States)

    Gonzalez, Sergio; Berthelot, Jade; Jiner, Jennifer; Perrin-Tricaud, Claire; Fernando, Ruani; Chrast, Roman; Lenaers, Guy; Tricaud, Nicolas

    2016-03-01

    Schwann cells produce myelin sheath around peripheral nerve axons. Myelination is critical for rapid propagation of action potentials, as illustrated by the large number of acquired and hereditary peripheral neuropathies, such as diabetic neuropathy or Charcot-Marie-Tooth diseases, that are commonly associated with a process of demyelination. However, the early molecular events that trigger the demyelination program in these diseases remain unknown. Here, we used virally delivered fluorescent probes and in vivo time-lapse imaging in a mouse model of demyelination to investigate the underlying mechanisms of the demyelination process. We demonstrated that mitochondrial calcium released by voltage-dependent anion channel 1 (VDAC1) after sciatic nerve injury triggers Schwann cell demyelination via ERK1/2, p38, JNK, and c-JUN activation. In diabetic mice, VDAC1 activity was altered, resulting in a mitochondrial calcium leak in Schwann cell cytoplasm, thereby priming the cell for demyelination. Moreover, reduction of mitochondrial calcium release, either by shRNA-mediated VDAC1 silencing or pharmacological inhibition, prevented demyelination, leading to nerve conduction and neuromuscular performance recovery in rodent models of diabetic neuropathy and Charcot-Marie-Tooth diseases. Therefore, this study identifies mitochondria as the early key factor in the molecular mechanism of peripheral demyelination and opens a potential opportunity for the treatment of demyelinating peripheral neuropathies.

  3. Small Heat Shock Proteins and Distal Hereditary Neuropathies.

    Science.gov (United States)

    Nefedova, V V; Muranova, L K; Sudnitsyna, M V; Ryzhavskaya, A S; Gusev, N B

    2015-12-01

    Classification of small heat shock proteins (sHsp) is presented and processes regulated by sHsp are described. Symptoms of hereditary distal neuropathy are described and the genes whose mutations are associated with development of this congenital disease are listed. The literature data and our own results concerning physicochemical properties of HspB1 mutants associated with Charcot-Marie-Tooth disease are analyzed. Mutations of HspB1, associated with hereditary motor neuron disease, can be accompanied by change of the size of HspB1 oligomers, by decreased stability under unfavorable conditions, by changes in the interaction with protein partners, and as a rule by decrease of chaperone-like activity. The largest part of these mutations is accompanied by change of oligomer stability (that can be either increased or decreased) or by change of intermonomer interaction inside an oligomer. Data on point mutation of HspB3 associated with axonal neuropathy are presented. Data concerning point mutations of Lys141 of HspB8 and those associated with hereditary neuropathy and different forms of Charcot-Marie-Tooth disease are analyzed. It is supposed that point mutations of sHsp associated with distal neuropathies lead either to loss of function (for instance, decrease of chaperone-like activity) or to gain of harmful functions (for instance, increase of interaction with certain protein partners).

  4. Testing for autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1984-01-01

    Autonomic neuropathy is a common complication in long-term diabetes, about 30% of the patients showing measurable signs of autonomic dysfunction after 10 years duration of disease. The diagnosis is often difficult to establish because clinical symptoms generally occur late in the course...

  5. Hereditary motor-sensory, motor, and sensory neuropathies in childhood.

    Science.gov (United States)

    Landrieu, Pierre; Baets, Jonathan; De Jonghe, Peter

    2013-01-01

    Hereditary neuropathies (HN) are categorized according to clinical presentation, pathogenic mechanism based on electrophysiology, genetic transmission, age of occurrence, and, in selected cases, pathological findings. The combination of these parameters frequently orients towards specific genetic disorders. Ruling out a neuropathy secondary to a generalized metabolic disorder remains the first pediatric concern. Primary, motor-sensory are the most frequent HN and are dominated by demyelinating AD forms (CMT1). Others are demyelinating AR forms, axonal AD/AR forms, and forms with "intermediate" electrophysiological phenotype. Pure motor HN represent40 genes with various biological functions have been found responsible for HN. Many are responsible for various phenotypes, including some without the polyneuropathic trait: for the pediatric neurologist, phenotype/genotype correlations constitute a permanent bidirectional exercise.

  6. Dorsal Root Ganglia Sensory Neuronal Cultures: a tool for drug discovery for peripheral neuropathies

    Science.gov (United States)

    Melli, Giorgia; Höke, Ahmet

    2010-01-01

    Background Peripheral neuropathies affect many people worldwide and are caused by or associated with a wide range of conditions, both genetic and acquired. Current therapies are directed at symptomatic control because no effective regenerative treatment exists. Primary challenge is that mechanisms that lead to distal axonal degeneration, a common feature of all peripheral neuropathies, are largely unknown. Objective/Methods To address the role and specific characteristics of dorsal root ganglia (DRG) derived sensory neuron culture system as a useful model in evaluating the pathogenic mechanisms of peripheral neuropathies and examination and validation of potential therapeutic compounds. A thorough review of the recent literature was completed and select examples of the use of DRG neurons in different peripheral neuropathy models were chosen to highlight the utility of these cultures. Conclusion Many useful models of different peripheral neuropathies have been developed using DRG neuronal culture and potential therapeutic targets have been examined, but so far none of the potential therapeutic compounds have succeeded in clinical trials. In recent years, focus has changed to evaluation of axon degeneration as the primary outcome measure advocating a drug development strategy starting with phenotypic drug screening, followed by validation in primary complex co-cultures and animal models. PMID:20657751

  7. Diagnosis of acute neuropathies

    DEFF Research Database (Denmark)

    Crone, Clarissa; Krarup, Christian

    2007-01-01

    Acute and subacute polyneuropathies present diagnostic challenges since many require prompt initiation of treatment in order to limit axonal degeneration and since an exact and detailed diagnosis is a prerequisite for making the correct choice of treatment. It is for instance of utmost importance...... to recognize whether the underlying pathological changes are due to demyelination or to axonal degeneration and electrodiagnostic tests can thus in most cases contribute considerably to the securing of an exact diagnosis. The specific and characteristic electrophysiological findings in the different types...

  8. Activity-Dependent Excitability Changes Suggest Na[superscript +]/K[superscript +] Pump Dysfunction in Diabetic Neuropathy

    Science.gov (United States)

    Krishnan, Arun V.; Lin, Cindy S.-Y.; Kiernan, Matthew C.

    2008-01-01

    The present study was undertaken to evaluate the role of Na[superscript +]/K[superscript +] pump dysfunction in the development of diabetic neuropathy (DN). Nerve excitability techniques, which provide information about membrane potential and axonal ion channel function, were undertaken in 15 patients with established DN and in 10 patients with…

  9. Autoimmune reactions in patients with M-component and peripheral neuropathy

    DEFF Research Database (Denmark)

    Jønsson, V; Schrøder, H D; Trojaborg, W;

    1992-01-01

    A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, Waldenström's disease in one patient......, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M...

  10. Nodes of ranvier and paranodes in chronic acquired neuropathies.

    Directory of Open Access Journals (Sweden)

    Carmen Cifuentes-Diaz

    Full Text Available Chronic acquired neuropathies of unknown origin are classified as chronic inflammatory demyelinating polyneuropathies (CIDP and chronic idiopathic axonal polyneuropathies (CIAP. The diagnosis can be very difficult, although it has important therapeutic implications since CIDP can be improved by immunomodulating treatment. The aim of this study was to examine the possible abnormalities of nodal and paranodal regions in these two types of neuropathies. Longitudinal sections of superficial peroneal nerves were obtained from biopsy material from 12 patients with CIDP and 10 patients with CIAP and studied by immunofluorescence and in some cases electron microscopy. Electron microscopy revealed multiple alterations in the nodal and paranodal regions which predominated in Schwann cells in CIDP and in axons in CIAP. In CIDP paranodin/Caspr immunofluorescence was more widespread than in control nerves, extending along the axon in internodes where it appeared intense. Nodal channels Nav and KCNQ2 were less altered but were also detected in the internodes. In CIAP paranodes, paranodin labeling was irregular and/or decreased. To test the consequences of acquired primary Schwann cells alteration on axonal proteins, we used a mouse model based on induced deletion of the transcription factor Krox-20 gene. In the demyelinated sciatic nerves of these mice we observed alterations similar to those found in CIDP by immunofluorescence, and immunoblotting demonstrated increased levels of paranodin. Finally we examined whether the alterations in paranodin immunoreactivity could have a diagnosis value. In a sample of 16 biopsies, the study of paranodin immunofluorescence by blind evaluators led to correct diagnosis in 70 ± 4% of the cases. This study characterizes for the first time the abnormalities of nodes of Ranvier in CIAP and CIDP, and the altered expression and distribution of nodal and paranodal proteins. Marked differences were observed between CIDP and CIAP

  11. Genetics Home Reference: ataxia neuropathy spectrum

    Science.gov (United States)

    ... Understand Genetics Home Health Conditions ataxia neuropathy spectrum ataxia neuropathy spectrum Enable Javascript to view the expand/ ... boxes. Download PDF Open All Close All Description Ataxia neuropathy spectrum is part of a group of ...

  12. Inherited autonomic neuropathies.

    Science.gov (United States)

    Axelrod, Felicia B; Hilz, Max J

    2003-12-01

    Inherited autonomic neuropathies are a rare group of disorders associated with sensory dysfunction. As a group they are termed the "hereditary sensory and autonomic neuropathies" (HSAN). Classification of the various autonomic and sensory disorders is ongoing. In addition to the numerical classification of four distinct forms proposed by Dyck and Ohta (1975), additional entities have been described. The best known and most intensively studied of the HSANs are familial dysautonomia (Riley-Day syndrome or HSAN type III) and congenital insensitivity to pain with anhidrosis (HSAN type IV). Diagnosis of the HSANs depends primarily on clinical examinations and specific sensory and autonomic assessments. Pathologic examinations are helpful in confirming the diagnosis and in differentiating between the different disorders. In recent years identification of specific genetic mutations for some disorders has aided diagnosis. Replacement or definitive therapies are not available for any of the disorders so that treatment remains supportive and directed toward specific symptoms.

  13. Inherited mitochondrial optic neuropathies

    Science.gov (United States)

    Yu-Wai-Man, P; Griffiths, P G; Hudson, G; Chinnery, P F

    2009-01-01

    Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (DOA) are the two most common inherited optic neuropathies and they result in significant visual morbidity among young adults. Both disorders are the result of mitochondrial dysfunction: LHON from primary mitochondrial DNA (mtDNA) mutations affecting the respiratory chain complexes; and the majority of DOA families have mutations in the OPA1 gene, which codes for an inner mitochondrial membrane protein critical for mtDNA maintenance and oxidative phosphorylation. Additional genetic and environmental factors modulate the penetrance of LHON, and the same is likely to be the case for DOA which has a markedly variable clinical phenotype. The selective vulnerability of retinal ganglion cells (RGCs) is a key pathological feature and understanding the fundamental mechanisms that underlie RGC loss in these disorders is a prerequisite for the development of effective therapeutic strategies which are currently limited. PMID:19001017

  14. Diabetic Neuropathy: Mechanisms to Management

    OpenAIRE

    2008-01-01

    Neuropathy is the most common and debilitating complication of diabetes and results in pain, decreased motility, and amputation. Diabetic neuropathy encompasses a variety of forms whose impact ranges from discomfort to death. Hyperglycemia induces oxidative stress in diabetic neurons and results in activation of multiple biochemical pathways. These activated pathways are a major source of damage and are potential therapeutic targets in diabetic neuropathy. Though therapies are available to al...

  15. Catecholamines and diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1995-01-01

    In diabetic patients with autonomic neuropathy plasma noradrenaline concentration, used as an index of sympathetic nervous activity, is low. This decrease is, however, only found in patients with a long duration of diabetes with clinically severe autonomic neuropathy. This apparent insensitivity...... of plasma catecholamine measurements is not due to changes in the clearance of catecholamines in diabetic autonomic neuropathy. The physiological responses to infused adrenaline and to noradrenaline are enhanced, for noradrenaline mainly cardiovascular responses. Adrenoceptors (alpha and beta adrenoceptors...

  16. Study of Autophagy and Microangiopathy in Sural Nerves of Patients with Chronic Idiopathic Axonal Polyneuropathy

    Science.gov (United States)

    Samuelsson, Kristin; Osman, Ayman A. M.; Angeria, Maria; Risling, Mårten; Mohseni, Simin; Press, Rayomand

    2016-01-01

    Twenty-five percent of polyneuropathies are idiopathic. Microangiopathy has been suggested to be a possible pathogenic cause of chronic idiopathic axonal polyneuropathy (CIAP). Dysfunction of the autophagy pathway has been implicated as a marker of neurodegeneration in the central nervous system, but the autophagy process is not explored in the peripheral nervous system. In the current study, we examined the presence of microangiopathy and autophagy-related structures in sural nerve biopsies of 10 patients with CIAP, 11 controls with inflammatory neuropathy and 10 controls without sensory polyneuropathy. We did not find any significant difference in endoneurial microangiopathic markers in patients with CIAP compared to normal controls, though we did find a correlation between basal lamina area thickness and age. Unexpectedly, we found a significantly larger basal lamina area thickness in patients with vasculitic neuropathy. Furthermore, we found a significantly higher density of endoneurial autophagy-related structures, particularly in patients with CIAP but also in patients with inflammatory neuropathy, compared to normal controls. It is unclear if the alteration in the autophagy pathway is a consequence or a cause of the neuropathy. Our results do not support the hypothesis that CIAP is primarily caused by a microangiopathic process in endoneurial blood vessels in peripheral nerves. The significantly higher density of autophagy structures in sural nerves obtained from patients with CIAP and inflammatory neuropathy vs. controls indicates the involvement of this pathway in neuropathy, particularly in CIAP, since the increase in density of autophagy-related structures was more pronounced in patients with CIAP than those with inflammatory neuropathy. To our knowledge this is the first report investigating signs of autophagy process in peripheral nerves in patients with CIAP and inflammatory neuropathy. PMID:27662650

  17. Painful peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    SUN Bo

    2013-09-01

    Full Text Available Painful peripheral neuropathy (PPN is characterized by neuropathic pain (NP, which is accompanied by dysfunction of motor, sensory and autonomic nervous system. It always involves small nerve fibers, including A δ and C fibers. PPN can be classified into two types according to etiology: hereditary and acquired. Pain of PPN can manifest as spontaneous pain and stimulus-evoked pain (allodynia, hyperalgesia and hyperpathia. The manifestation of typical cases is length-dependent, which firstly involves the feet, and then progresses proximally and to the hands, presenting a glove-stock pattern. PPN can be either an isolated disease entity or part of other diseases. The former indicates idiopathic small fiber neuropathy (SFN, while the latter contains various diseases involving peripheral nerve fibers, including systemic diseases such as diabetes mellitus and peripheral neuropathy with other causes. The accessory examinations of PPN include quantitative sensory testing (QST, intraepidermal nerve fiber density (IENFD, sympathetic skin response (SSR, etc. Among them, IENFD is the "golden standard" for SFN. The major therapeutic methods are to control primary diseases and relieve pain. Medications alleviating neuropathic pain consist of carbamazepine, pregabalin, gabapentin and amitriptyline, etc.

  18. Drug-induced peripheral neuropathy

    DEFF Research Database (Denmark)

    Vilholm, Ole Jakob; Christensen, Alex Alban; Zedan, Ahmed;

    2014-01-01

    Peripheral neuropathy can be caused by medication, and various descriptions have been applied for this condition. In this MiniReview, the term 'drug-induced peripheral neuropathy' (DIPN) is used with the suggested definition: Damage to nerves of the peripheral nervous system caused by a chemical...... substance used in the treatment, cure, prevention or diagnosis of a disease. Optic neuropathy is included in this definition. A distinction between DIPN and other aetiologies of peripheral neuropathy is often quite difficult and thus, the aim of this MiniReview is to discuss the major agents associated...

  19. Prediction of Functional Outcome in Axonal Guillain-Barre Syndrome

    Science.gov (United States)

    2016-01-01

    Objective To identify the factors that could predict the functional outcome in patients with the axonal type of Guillain-Barre syndrome (GBS). Methods Two hundred and two GBS patients admitted to our university hospital between 2003 and 2014 were reviewed retrospectively. We defined a good outcome as being "able to walk independently at 1 month after onset" and a poor outcome as being "unable to walk independently at 1 month after onset". We evaluated the factors that differed between the good and poor outcome groups. Results Twenty-four patients were classified into the acute motor axonal neuropathy type. There was a statistically significant difference between the good and poor outcome groups in terms of the GBS disability score at admission, and GBS disability score and Medical Research Council sum score at 1 month after admission. In an electrophysiologic analysis, the good outcome group showed greater amplitude of median, ulnar, deep peroneal, and posterior tibial nerve compound muscle action potentials (CMAP) and greater amplitude of median, ulnar, and superficial peroneal sensory nerve action potentials (SNAP) than the poor outcome group. Conclusion A lower GBS disability score at admission, high amplitude of median, ulnar, deep peroneal, and posterior tibial CMAPs, and high amplitude of median, ulnar, and superficial peroneal SNAPs were associated with being able to walk at 1 month in patients with axonal GBS. PMID:27446785

  20. Diagnosis and management of neuropathies associated with plasma cell dyscrasias.

    Science.gov (United States)

    Rosenbaum, Evan; Marks, Douglas; Raza, Shahzad

    2017-04-10

    Neuropathies associated with plasma cell dyscrasias are a major cause of morbidity for patients managed by medical oncologists. Because of similarities in clinical presentation and on nerve conduction studies, identifying the underlying disease leading to a paraproteinemic neuropathy can often be difficult. In addition, the degree of neurologic deficit does not strictly correlate with the extent of abnormalities on common clinical laboratory testing. Fortunately, with increasing understanding into the biologic mechanisms of underlying hematologic diseases, additional biomarkers have recently been developed, thus improving our diagnostic capacity. Neuropathies associated with plasma cells dyscrasias are seen with Monoclonal gammopathy of undetermined significance (MGUS) particularly IgM subtype, followed by IgG and IgA MGUS, multiple myeloma, Waldenström's macroglobulinemia, amyloid, Castleman's disease, and POEMS syndrome. The mechanisms of neuronal injury associated with plasma cell dyscrasia vary based on underlying diagnosis and include malignant infiltration, immune-mediated antibody deposition, or local compression of nerve roots. The polyneuropathies are frequently demyelinating, although axonal and mixed neuropathies can also be seen. As demonstrated by the cases included in this review, patients frequently present with symmetric sensory disturbance, followed by progressive motor weakness. Unfortunately, because of the complexity of diagnostic testing, patients are frequently examined late, often after receiving several ineffective therapies. The aim of this case-based review is to provide clinicians with insight on how to properly recognize these atypical neuropathies and send the appropriate diagnostic work, increasing the likelihood of accurately classify the patient's underlying hematologic disorder. Copyright © 2017 John Wiley & Sons, Ltd.

  1. The genetics of axonal transport and axonal transport disorders.

    Directory of Open Access Journals (Sweden)

    Jason E Duncan

    2006-09-01

    Full Text Available Neurons are specialized cells with a complex architecture that includes elaborate dendritic branches and a long, narrow axon that extends from the cell body to the synaptic terminal. The organized transport of essential biological materials throughout the neuron is required to support its growth, function, and viability. In this review, we focus on insights that have emerged from the genetic analysis of long-distance axonal transport between the cell body and the synaptic terminal. We also discuss recent genetic evidence that supports the hypothesis that disruptions in axonal transport may cause or dramatically contribute to neurodegenerative diseases.

  2. Myanmarese Neuropathy: Clinical Description of Acute Peripheral Neuropathy Detected among Myanmarese Refugees in Malaysia.

    Science.gov (United States)

    Fu Liong, Hiew; Santhi, Datuk Puvanarajah; Shanthi, Viswanathan; Mohd Hanip, Rafia

    2014-01-01

    Background. Since 2008, we have observed an increasing number of Myanmarese refugees in Malaysia being admitted for acute/subacute onset peripheral neuropathy. Most of them had a preceding history of starvation. Methods. We retrospectively studied the clinical features of all Myanmarese patients admitted with peripheral neuropathy from September 2008 to January 2014. Results. A total of 24 patients from the Chin, Rohingya, and Rakhine ethnicities (mean age, 23.8 years; male, 96%) had symmetrical, ascending areflexic weakness with at least one additional presenting symptom of fever, lower limb swelling, vomiting, abdominal pain, or difficulty in breathing. Twenty (83.3%) had sensory symptoms. Ten (41.6%) had cranial nerve involvement. Nineteen patients had cerebrospinal fluid examinations but none with evidence of albuminocytological dissociation. Neurophysiological assessment revealed axonal polyneuropathy, predominantly a motor-sensory subtype. Folate and vitamin B12 deficiencies were detected in 31.5% of them. These findings suggested the presence of a polyneuropathy related to nutrition against a backdrop of other possible environmental factors such as infections, metabolic disorders, or exposure to unknown toxin. Supportive treatment with appropriate vitamins supplementation improved functional outcome in most patients. Conclusion. We report a spectrum of acquired reversible neurological manifestations among Myanmarese refugees likely to be multifactorial with micronutrient deficiencies playing an important role in the pathogenesis.

  3. The Highwire ubiquitin ligase promotes axonal degeneration by tuning levels of Nmnat protein.

    Directory of Open Access Journals (Sweden)

    Xin Xiong

    Full Text Available Axonal degeneration is a hallmark of many neuropathies, neurodegenerative diseases, and injuries. Here, using a Drosophila injury model, we have identified a highly conserved E3 ubiquitin ligase, Highwire (Hiw, as an important regulator of axonal and synaptic degeneration. Mutations in hiw strongly inhibit Wallerian degeneration in multiple neuron types and developmental stages. This new phenotype is mediated by a new downstream target of Hiw: the NAD+ biosynthetic enzyme nicotinamide mononucleotide adenyltransferase (Nmnat, which acts in parallel to a previously known target of Hiw, the Wallenda dileucine zipper kinase (Wnd/DLK MAPKKK. Hiw promotes a rapid disappearance of Nmnat protein in the distal stump after injury. An increased level of Nmnat protein in hiw mutants is both required and sufficient to inhibit degeneration. Ectopically expressed mouse Nmnat2 is also subject to regulation by Hiw in distal axons and synapses. These findings implicate an important role for endogenous Nmnat and its regulation, via a conserved mechanism, in the initiation of axonal degeneration. Through independent regulation of Wnd/DLK, whose function is required for proximal axons to regenerate, Hiw plays a central role in coordinating both regenerative and degenerative responses to axonal injury.

  4. Inflammatory neuropathies: pathology, molecular markers and targets for specific therapeutic intervention.

    Science.gov (United States)

    Ubogu, Eroboghene E

    2015-10-01

    Inflammatory neuropathies encompass groups of heterogeneous disorders characterized by pathogenic immune-mediated hematogenous leukocyte infiltration of peripheral nerves, nerve roots or both, with resultant demyelination or axonal degeneration or both. Inflammatory neuropathies may be divided into three major disease categories: Guillain-Barré syndrome (particularly the acute inflammatory demyelinating polyradiculoneuropathy variant), chronic inflammatory demyelinating polyradiculoneuropathy and nonsystemic vasculitic neuropathy (or peripheral nerve vasculitis). Despite major advances in molecular biology, pathology and genetics, the pathogenesis of these disorders remains elusive. There is insufficient knowledge on the mechanisms of hematogenous leukocyte trafficking into the peripheral nervous system to guide the development of specific molecular therapies for immune-mediated inflammatory neuropathies compared to disorders such as psoriasis, inflammatory bowel disease, rheumatoid arthritis or multiple sclerosis. The recent isolation and characterization of human endoneurial endothelial cells that form the blood-nerve barrier provides an opportunity to elucidate leukocyte-endothelial cell interactions critical to the pathogenesis of inflammatory neuropathies at the interface between the systemic circulation and peripheral nerve endoneurium. This review discusses our current knowledge of the classic pathological features of inflammatory neuropathies, attempts at molecular classification and genetic determinants, the utilization of in vitro and in vivo animal models to determine pathogenic mechanisms at the interface between the systemic circulation and the peripheral nervous system relevant to these disorders and prospects for future potential molecular pathology biomarkers and targets for specific therapeutic intervention.

  5. DGAT2 Mutation in a Family with Autosomal-Dominant Early-Onset Axonal Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Hong, Young Bin; Kang, Junghee; Kim, Ji Hyun; Lee, Jinho; Kwak, Geon; Hyun, Young Se; Nam, Soo Hyun; Hong, Hyun Dae; Choi, Yu-Ri; Jung, Sung-Chul; Koo, Heasoo; Lee, Ji Eun; Choi, Byung-Ok; Chung, Ki Wha

    2016-05-01

    Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral neuropathy and is a genetically and clinically heterogeneous disorder. We examined a Korean family in which two individuals had an autosomal-dominant axonal CMT with early-onset, sensory ataxia, tremor, and slow disease progression. Pedigree analysis and exome sequencing identified a de novo missense mutation (p.Y223H) in the diacylglycerol O-acyltransferase 2 (DGAT2) gene. DGAT2 encodes an endoplasmic reticulum-mitochondrial-associated membrane protein, acyl-CoA:diacylglycerol acyltransferase, which catalyzes the final step of the triglyceride (TG) biosynthesis pathway. The patient showed consistently decreased serum TG levels, and overexpression of the mutant DGAT2 significantly inhibited the proliferation of mouse motor neuron cells. Moreover, the variant form of human DGAT2 inhibited the axonal branching in the peripheral nervous system of zebrafish. We suggest that mutation of DGAT2 is the novel underlying cause of an autosomal-dominant axonal CMT2 neuropathy. This study will help provide a better understanding of the pathophysiology of axonal CMT and contribute to the molecular diagnostics of peripheral neuropathies. © 2016 WILEY PERIODICALS, INC.

  6. Profound and persistent painful paclitaxel peripheral neuropathy in a premenopausal patient.

    LENUS (Irish Health Repository)

    Quintyne, K I

    2011-01-01

    The authors herein report the case of a 35-year-old woman undergoing adjuvant therapy for node positive breast cancer, who presented with short and rapidly progressive history of bilateral lower limb symptoms of peripheral neuropathy following therapy with paclitaxel. MRI of her neural axis revealed no leptomeningeal enhancement or focal metastatic lesions. Neurophysiological tests favoured toxic sensory axonal polyneuropathy. She remains symptomatic following discontinuation of therapy 20 months ago, and is under review with pain management.

  7. Peripheral neuropathy in a copper-deficient goat

    Directory of Open Access Journals (Sweden)

    Valdir Morais de Almeida

    2017-09-01

    Full Text Available ABSTRACT: This report aimed to describe a case of peripheral neuropathy in a copper-deficient goat, and highlights the clinical, and pathological features of the disease. The goat had low body score, hyporexia, alopecia, achromotrichia, left hindlimb protraction, paralysis with dragging of digit and difficulty to stand up and microcytic normochromic anemia. Copper concentration in serum was markedly lower (2.0µmol L-1 whereas the iron serum content was significantly increased (51.0µmol L-1. The main gross alteration was the reduction of the quadriceps vastus laterallis muscle volume. Histologically, there was atrophy of the quadriceps vastus laterallis muscle and presence of satellite cells, infiltration of lymphocytes, macrophages and replacement of the fibers by connective tissue. In the femoral nerve, there was axonal degeneration with myelin sheath expansion and presence of vacuoles, usually in chains and containing axonal debris or macrophages. Clinical, laboratorial and pathologic findings are consistent with peripheral neuropathy due to a severy copper deficiency.

  8. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons

    DEFF Research Database (Denmark)

    Alvarez Herrero, Susana; Pinchenko, Volodymyr; Klein, Dennis

    2011-01-01

    by pharmacologic block using the subtype-selective Na(V)1.8 blocker A-803467 and chronically in Na(V)1.8 knock-outs. We found that in the context of dysmyelination, abnormal potassium ion currents and membrane depolarization, the ectopic Na(V)1.8 channels further impair the motor axon excitability in protein zero...... and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which...... is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies...

  9. [Atypical neuropathies associated with diabetes].

    Science.gov (United States)

    Lozeron, P

    2014-12-01

    Diabetes is the leading cause of neuropathy worldwide and, due to the epidemic progression of the affection, prevalence of diabetic neuropathies will increase in the near future. Beside the typical diabetic neuropathy pattern and the common entrapment neuropathies, several unusual clinical forms have been described with either a symmetrical or an asymmetrical pattern. Treatment-induced neuropathy is an acute sensory affection most commonly related to acute glycemic control. Pain is debilitating and associated with vegetative dysfunction. Prevention is important, as resolution is often incomplete. Several patterns or asymmetrical neuropathies of inflammatory and ischemic origin were described long ago in the lower limb. They are debilitating, most often painful and require steroid treatment. Other patterns affecting the thoracolumbar region or the upper limbs or involving a painless motor deficit must be identified as specific treatments are sometimes needed. An association between diabetes and chronic inflammatory demyelinating polyneuropathy has not been demonstrated but diagnosis may be suggested due to the misleading low conduction velocities seen in classical diabetic neuropathy. Like any other patient, the diabetic patient may present a neuropathy unrelated to diabetes. To facilitate patient care, neurologists should be aware of such clinical entities. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. [Surgical therapy for entrapment neuropathy].

    Science.gov (United States)

    Tachibana, Shigekuni

    2012-01-01

    Entrapment neuropathy is not uncommon, and surgical treatment is followed by favorite result. Therefore, to obtain an accurate diagnosis based on precise knowledge of the peripheral nervous system is very important. The most popular and useful symptoms and signs of the entrapment neuropathy is paresthesia, dysesthesia and Tinel's like sign at the lesion site. Nerve conduction study is also valuable for the accurate diagnosis. For the last 30 years, the author operated on 1,399 lesions of entrapment neuropathy. They consist of 877 carpal tunnel syndrome (63%), 284 tarsal tunnel syndrome (20%), 135 ulnar neuropathy at the elbow (10%), 53 piriformis syndrome (4%), 15 thoracic outlet syndrome (1%), and others. From the pathophysiological point to view, except for the carpal tunnel syndrome, several locations and factors come into play producing the entrapment of the nerve. The author would like to stress that the entrapment neuropathy is not severe disease, though, it strongly insult the patient's quality of life.

  11. Leprosy neuropathy evaluated by NCS is independent of the patient's infectious state.

    Science.gov (United States)

    Jardim, M R; Vital, R; Hacker, M A; Nascimento, M; Balassiano, S L; Sarno, E N; Illarramendi, X

    2015-04-01

    Leprosy causes nerve injury, which mimics clinical and neurophysiological conditions, rendering it an excellent model of peripheral neuropathy. A retrospective study including 822 nerve conduction studies (NCS) of 509 patients was developed to appraise the electrophysiological pattern of leprosy neuropathy. NCS of motor and sensory nerves performed before, during, and after multidrug therapy (MDT) were analyzed. During the three periods of MDT, while NCS alterations were similar regarding extension, topography, damage severity, and type of lesion, NCS showed that sensory was more frequent (sural nerve) (92-96%) than motor impairment (70-77%) (ulnar nerve). Once axonal loss has been installed, nerve function is little affected by inflammatory, immune and/or bacterial events since chronic neuropathy has been established, inevitably leading to the well-known leprosy sequelae occurring at any time before and/or after leprosy diagnosis. Published by Elsevier B.V.

  12. Painful neuropathy: Mechanisms.

    Science.gov (United States)

    Lee-Kubli, Corinne A; Calcutt, Nigel A

    2014-01-01

    Painful neuropathy, like the other complications of diabetes, is a growing healthcare concern. Unfortunately, current treatments are of variable efficacy and do not target underlying pathogenic mechanisms, in part because these mechanisms are not well defined. Rat and mouse models of type 1 diabetes are frequently used to study diabetic neuropathy, with rats in particular being consistently reported to show allodynia and hyperalgesia. Models of type 2 diabetes are being used with increasing frequency, but the current literature on the progression of indices of neuropathic pain is variable and relatively few therapeutics have yet been developed in these models. While evidence for spontaneous pain in rodent models is sparse, measures of evoked mechanical, thermal and chemical pain can provide insight into the pathogenesis of the condition. The stocking and glove distribution of pain tantalizingly suggests that the generator site of neuropathic pain is found within the peripheral nervous system. However, emerging evidence demonstrates that amplification in the spinal cord, via spinal disinhibition and neuroinflammation, and also in the brain, via enhanced thalamic activity or decreased cortical inhibition, likely contribute to the pathogenesis of painful diabetic neuropathy. Several potential therapeutic strategies have emerged from preclinical studies, including prophylactic treatments that intervene against underlying mechanisms of disease, treatments that prevent gains of nociceptive function, treatments that suppress enhancements of nociceptive function, and treatments that impede normal nociceptive mechanisms. Ongoing challenges include unraveling the complexity of underlying pathogenic mechanisms, addressing the potential disconnect between the perceived location of pain and the actual pain generator and amplifier sites, and finding ways to identify which mechanisms operate in specific patients to allow rational and individualized choice of targeted therapies.

  13. Delayed radiation neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  14. Experimental germanium dioxide-induced neuropathy in rats.

    Science.gov (United States)

    Matsumuro, K; Izumo, S; Higuchi, I; Ronquillo, A T; Takahashi, K; Osame, M

    1993-01-01

    We report an experimental model of germanium dioxide (GeO2)-induced neuropathy in rats. More than 6 months administration of GeO2 to young rats produced neuropathy characterized by segmental demyelination/remyelination and nerve edema. Electron microscopic studies demonstrated that changes in Schwann cells, such as an increased cytoplasmic volume or disintegration of the cytoplasm, were the earliest pathological findings. Schwann cell mitochondria contained high electron-dense materials. Subsequent removal of necrotic Schwann cell debris and myelin by invading macrophages was evident. These findings suggested that the Schwann cells themselves are the primary target of the toxin. The deposition of electron-dense granules in the intra-axonal vesicles, which was suggestive of glycogen granules in mitochondria, was observed in the advanced stage of the neuropathy. The findings of endoneurial edema with splitting of myelin lamellae were noted at the early stage of demyelination. Nerve edema may be the result of GeO2-induced endothelial cell injury.

  15. Organophosphorus agent induced delayed neuropathy: a case report

    Directory of Open Access Journals (Sweden)

    Harshit Acharya

    2016-02-01

    Full Text Available A 40-year old male, was presented with complaint of difficulty in walking with inability to flex foot and toes in bilateral feet ( and ldquo;foot drop and rdquo;, which was acute at the onset and gradually progressive since the past 7 days. The patient's wife and their 2 children had similar complaint with the same period of onset. At home, his family used cottonseed oil as cooking oil with wheat grain mixed with castor oil. On neurological examination, he was found to have lower motor neuron weakness with spasticity. After ruling out other common causes of polyneuropathy and lower motor weakness; due to high suspicion of poisoning by food adulterant, RBC acetyl cholinesterase (AChE and plasma cholinesterase (BuChE were tested at National Institute of Occupational Health (NIOH, which came low and confirmed diagnosis of Organophosphorus (OP poisoning. Nerve conduction study was done; which showed decreased amplitude of conduction in bilateral peroneal and right tibial nerve along with decreased mean nerve conduction velocity of bilateral median nerve. Thus patient was diagnosed with organophosphorus agent induced delayed axonal type of polyneuropathy and physiotherapy was started as treatment. OP compounds are a diverse group of chemicals which are principally used as insecticides in agriculture. Following organophosphate poisoning (OPP, 3 well-defined neurological syndromes are recognised: cholinergic crisis, intermediate syndrome and delayed polyneuropathy. Some organophosphates, particularly triorthocresyl phosphate (TOCP and tricresyl phosphate (TCP, produce delayed neuropathy. On ingestion, they do not produce significant cholinergic crisis, but 7 to 20 days later it leads to a pure motor axonal neuropathy with wrist and foot drop. The mechanism may involve inhibition of neuropathy target esterase (NTE, which is found in the brain, peripheral nerves, and lymphocytes. This form of toxicity has been seen occasionally in small epidemics in

  16. A Stochastic Multiscale Model That Explains the Segregation of Axonal Microtubules and Neurofilaments in Neurological Diseases.

    Directory of Open Access Journals (Sweden)

    Chuan Xue

    2015-08-01

    Full Text Available The organization of the axonal cytoskeleton is a key determinant of the normal function of an axon, which is a long thin projection of a neuron. Under normal conditions two axonal cytoskeletal polymers, microtubules and neurofilaments, align longitudinally in axons and are interspersed in axonal cross-sections. However, in many neurotoxic and neurodegenerative disorders, microtubules and neurofilaments segregate apart from each other, with microtubules and membranous organelles clustered centrally and neurofilaments displaced to the periphery. This striking segregation precedes the abnormal and excessive neurofilament accumulation in these diseases, which in turn leads to focal axonal swellings. While neurofilament accumulation suggests an impairment of neurofilament transport along axons, the underlying mechanism of their segregation from microtubules remains poorly understood for over 30 years. To address this question, we developed a stochastic multiscale model for the cross-sectional distribution of microtubules and neurofilaments in axons. The model describes microtubules, neurofilaments and organelles as interacting particles in a 2D cross-section, and is built upon molecular processes that occur on a time scale of seconds or shorter. It incorporates the longitudinal transport of neurofilaments and organelles through this domain by allowing stochastic arrival and departure of these cargoes, and integrates the dynamic interactions of these cargoes with microtubules mediated by molecular motors. Simulations of the model demonstrate that organelles can pull nearby microtubules together, and in the absence of neurofilament transport, this mechanism gradually segregates microtubules from neurofilaments on a time scale of hours, similar to that observed in toxic neuropathies. This suggests that the microtubule-neurofilament segregation can be a consequence of the selective impairment of neurofilament transport. The model generates the

  17. The Ultrasound pattern sum score - UPSS. A new method to differentiate acute and subacute neuropathies using ultrasound of the peripheral nerves.

    Science.gov (United States)

    Grimm, Alexander; Décard, Bernhard F; Axer, Hubertus; Fuhr, Peter

    2015-11-01

    Ultrasound differentiation of neuropathies is a great challenge. We, therefore, suggest a standardized score to operationalize differentiation between several acute and subacute onset neuropathies. We retrospectively analyzed the ultrasound data of 61 patients with acute or subacute neuropathies, e.g. chronic immune-mediated neuropathies, Guillain-Barré syndrome (GBS), and axonal/vasculitic neuropathies. We compared these data to 28 healthy controls. Based on these results an ultrasound pattern sum score (UPSS) with three sub-scores (UPS-A for the sensorimotor nerves, UPS-B for the cervical roots and the vagal nerve and UPS-C for the sural nerve) was developed. Afterwards, the applicability of the score was prospectively validated in 10 patients with chronic neuropathies and in 14 patients with unknown acute and subacute PNP before performing additional tests. UPS-A and UPSS were significantly higher in CIDP than in other neuropathies and controls (pneuropathies (p85%. Vasculitic neuropathies showed an intermediate type of UPSS compared to other axonal neuropathies (p<0.001). In the prospective application the pattern score could be used with good accuracy in several types of neuropathy. UPS-A and UPSS operationalize to diagnose acute and subacute-onset CIDP and its variants with high sensitivity, specificity, and PPV. An increased UPS-B with normal UPSS and other sub scores may point to the diagnosis of GBS with high PPV and enables the differentiation from CIDP. Using the UPSS and its sub-scores gives a new diagnostic power to the method of the peripheral nerve ultrasound. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  18. A controlled investigation of the cause of chronic idiopathic axonal polyneuropathy.

    Science.gov (United States)

    Hughes, R A C; Umapathi, T; Gray, I A; Gregson, N A; Noori, M; Pannala, A S; Proteggente, A; Swan, A V

    2004-08-01

    To investigate the aetiology of chronic idiopathic axonal polyneuropathy (CIAP), 50 consecutive patients were compared with 50 control subjects from the same region. There were 22 patients with painful neuropathy and 28 without pain, 26 with sensory neuropathy and 24 with sensory and motor neuropathy. The typical picture was a gradually progressive sensory or sensory and motor neuropathy. It caused mild or sometimes moderate disability, and reduced the quality of life. There was no evidence that alcohol, venous insufficiency, arterial disease or antibodies to peripheral nerve antigens played a significant part. There was a possible history of peripheral neuropathy in the first or second-degree relatives of six patients and no controls (P = 0.01), and claw toes were present in 12 patients and four controls (P = 0.03). Thirty-two per cent of the patients and 14% of the controls had impaired glucose tolerance or fasting hyperglycaemia but, after adjusting for age and sex, the difference was not significant (P = 0.45), even in the painful neuropathy subgroup. The mean (SD) fasting insulin concentrations were significantly (P = 0.01) higher in the patients [75.9 (44.4) mmol/l] than the controls [47.3 (37.9) mmol/l], and the mean was higher still in the painful neuropathy subgroup [92.2 (37.1) mmol/l] (P environmental toxin exposure and hypertriglyceridaemia, but not glucose intolerance or alcohol overuse as significant risk factors that deserve further investigation as possible causes of CIAP.

  19. A global in vivo Drosophila RNAi screen identifies a key role of ceramide phosphoethanolamine for glial ensheathment of axons.

    Directory of Open Access Journals (Sweden)

    Aniket Ghosh

    Full Text Available Glia are of vital importance for all complex nervous system. One of the many functions of glia is to insulate and provide trophic and metabolic support to axons. Here, using glial-specific RNAi knockdown in Drosophila, we silenced 6930 conserved genes in adult flies to identify essential genes and pathways. Among our screening hits, metabolic processes were highly represented, and genes involved in carbohydrate and lipid metabolic pathways appeared to be essential in glia. One critical pathway identified was de novo ceramide synthesis. Glial knockdown of lace, a subunit of the serine palmitoyltransferase associated with hereditary sensory and autonomic neuropathies in humans, resulted in ensheathment defects of peripheral nerves in Drosophila. A genetic dissection study combined with shotgun high-resolution mass spectrometry of lipids showed that levels of ceramide phosphoethanolamine are crucial for axonal ensheathment by glia. A detailed morphological and functional analysis demonstrated that the depletion of ceramide phosphoethanolamine resulted in axonal defasciculation, slowed spike propagation, and failure of wrapping glia to enwrap peripheral axons. Supplementing sphingosine into the diet rescued the neuropathy in flies. Thus, our RNAi study in Drosophila identifies a key role of ceramide phosphoethanolamine in wrapping of axons by glia.

  20. [2012 literature review on peripheral neuropathies: immune neuropathies (treatments excluded)].

    Science.gov (United States)

    Nicolas, G

    2013-12-01

    In 2012, interest remains high in the field of dysimmune neuropathies, chiefly concerning Guillain-Barré syndrome (GBS). The pathophysiological mechanisms are now better known but electrophysiological criteria should be updated. The risk of GBS in H1N1 vaccination is now well evaluated. Nerve ultrasonography provides new prospects for diagnosis and follow-up of dysimmune neuropathies but cannot substitute for electrophysiology. This paper aims to present some noteworthy articles published in 2012 in the field of dysimmune neuropathies. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?

    Science.gov (United States)

    Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

    2003-05-01

    Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency.

  2. Treatment of hereditary optic neuropathies.

    Science.gov (United States)

    Newman, Nancy J

    2012-10-01

    The hereditary optic neuropathies are inherited disorders in which optic nerve dysfunction is a prominent feature in the phenotypic expression of disease. Optic neuropathy may be primarily an isolated finding, such as in Leber hereditary optic neuropathy and dominant optic atrophy, or part of a multisystem disorder. The pathophysiological mechanisms underlying the hereditary optic neuropathies involve mitochondrial dysfunction owing to mutations in mitochondrial or nuclear DNA that encodes proteins essential to mitochondrial function. Effective treatments are limited, and current management includes therapies directed at enhancing mitochondrial function and preventing oxidative damage, as well as genetic counselling, and supportive and symptomatic measures. New therapies, including gene therapy, are emerging via animal models and human clinical trials. Leber hereditary optic neuropathy, in particular, provides a unique model for testing promising treatments owing to its characteristic sequential bilateral involvement and the accessibility of target tissue within the eye. Lessons learned from treatment of the hereditary optic neuropathies may have therapeutic implications for other disorders of presumed mitochondrial dysfunction. In this Review, the natural history of the common inherited optic neuropathies, the presumed pathogenesis of several of these disorders, and the literature to date regarding potential therapies are summarized.

  3. Auditory Neuropathy - A Case of Auditory Neuropathy after Hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Maliheh Mazaher Yazdi

    2007-12-01

    Full Text Available Background and Aim: Auditory neuropathy is an hearing disorder in which peripheral hearing is normal, but the eighth nerve and brainstem are abnormal. By clinical definition, patient with this disorder have normal OAE, but exhibit an absent or severely abnormal ABR. Auditory neuropathy was first reported in the late 1970s as different methods could identify discrepancy between absent ABR and present hearing threshold. Speech understanding difficulties are worse than can be predicted from other tests of hearing function. Auditory neuropathy may also affect vestibular function. Case Report: This article presents electrophysiological and behavioral data from a case of auditory neuropathy in a child with normal hearing after bilirubinemia in a 5 years follow-up. Audiological findings demonstrate remarkable changes after multidisciplinary rehabilitation. Conclusion: auditory neuropathy may involve damage to the inner hair cells-specialized sensory cells in the inner ear that transmit information about sound through the nervous system to the brain. Other causes may include faulty connections between the inner hair cells and the nerve leading from the inner ear to the brain or damage to the nerve itself. People with auditory neuropathy have OAEs response but absent ABR and hearing loss threshold that can be permanent, get worse or get better.

  4. Sodium and Potassium Currents Influence Wallerian Degeneration of Injured Drosophila Axons

    Science.gov (United States)

    Mishra, Bibhudatta; Carson, Ross; Hume, Richard I.

    2013-01-01

    Axons degenerate after injury and in neuropathies and disease via a self-destruction program whose mechanism is poorly understood. Axons that have lost connection to their cell bodies have altered electrical and synaptic activities, but whether such changes play a role in the axonal degeneration process is not clear. We have used a Drosophila model to study the Wallerian degeneration of motoneuron axons and their neuromuscular junction synapses. We found that degeneration of the distal nerve stump after a nerve crush is greatly delayed when there is increased potassium channel activity (by overexpression of two different potassium channels, Kir2.1 and dORKΔ-C) or decreased voltage-gated sodium channel activity (using mutations in the para sodium channel). Conversely, degeneration is accelerated when potassium channel activity is decreased (by expressing a dominant-negative mutation of Shaker). Despite the effect of altering voltage-gated sodium and potassium channel activity, recordings made after nerve crush demonstrated that the distal stump does not fire action potentials. Rather, a variety of lines of evidence suggest that the sodium and potassium channels manifest their effects upon degeneration through changes in the resting membrane potential, which in turn regulates the level of intracellular free calcium within the isolated distal axon. PMID:24285879

  5. Transcellular degradation of axonal mitochondria.

    Science.gov (United States)

    Davis, Chung-ha O; Kim, Keun-Young; Bushong, Eric A; Mills, Elizabeth A; Boassa, Daniela; Shih, Tiffany; Kinebuchi, Mira; Phan, Sebastien; Zhou, Yi; Bihlmeyer, Nathan A; Nguyen, Judy V; Jin, Yunju; Ellisman, Mark H; Marsh-Armstrong, Nicholas

    2014-07-01

    It is generally accepted that healthy cells degrade their own mitochondria. Here, we report that retinal ganglion cell axons of WT mice shed mitochondria at the optic nerve head (ONH), and that these mitochondria are internalized and degraded by adjacent astrocytes. EM demonstrates that mitochondria are shed through formation of large protrusions that originate from otherwise healthy axons. A virally introduced tandem fluorophore protein reporter of acidified mitochondria reveals that acidified axonal mitochondria originating from the retinal ganglion cell are associated with lysosomes within columns of astrocytes in the ONH. According to this reporter, a greater proportion of retinal ganglion cell mitochondria are degraded at the ONH than in the ganglion cell soma. Consistently, analyses of degrading DNA reveal extensive mtDNA degradation within the optic nerve astrocytes, some of which comes from retinal ganglion cell axons. Together, these results demonstrate that surprisingly large proportions of retinal ganglion cell axonal mitochondria are normally degraded by the astrocytes of the ONH. This transcellular degradation of mitochondria, or transmitophagy, likely occurs elsewhere in the CNS, because structurally similar accumulations of degrading mitochondria are also found along neurites in superficial layers of the cerebral cortex. Thus, the general assumption that neurons or other cells necessarily degrade their own mitochondria should be reconsidered.

  6. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Science.gov (United States)

    Ayhan, Ziya; Yaman, Aylin; Söylev Bajin, Meltem; Saatci, A. Osman

    2015-01-01

    Optic disc drusen (ODD) are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION) who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION. PMID:26550507

  7. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Directory of Open Access Journals (Sweden)

    Ziya Ayhan

    2015-01-01

    Full Text Available Optic disc drusen (ODD are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION.

  8. [Leber's hereditary optic neuropathy].

    Science.gov (United States)

    Leo-Kottler, B; Wissinger, B

    2011-12-01

    Leber's hereditary optic neuropathy (LHON) is a rare disease primarily affecting the retinal ganglion cells. In most cases patients with LHON develop permanent visual loss with a large central scotoma in the visual field of both eyes. The optic disc becomes partially or completely pale. At the onset of the disease many patients are considered to suffer from an optic neuritis and are treated under the diagnostic and therapeutic regimen of optic neuritis. LHON is mostly only considered when high dose cortisone therapy fails to be effective or the second eye is affected. Thereafter, molecular genetic analysis will prove LHON in these cases. Detailed anamnesis including pedigree analysis in combination with observance of the peripapillary microangiopathic alterations at the fundus will help to speed up the diagnosis of LHON, but even after exact clinical and molecular genetic diagnosis of LHON some aspects of the disease still remain a mystery today.

  9. Two Novel De Novo GARS Mutations Cause Early-Onset Axonal Charcot-Marie-Tooth Disease.

    Directory of Open Access Journals (Sweden)

    Yi-Chu Liao

    Full Text Available Mutations in the GARS gene have been identified in a small number of patients with Charcot-Marie-Tooth disease (CMT type 2D or distal spinal muscular atrophy type V, for whom disease onset typically occurs during adolescence or young adulthood, initially manifesting as weakness and atrophy of the hand muscles. The role of GARS mutations in patients with inherited neuropathies in Taiwan remains elusive.Mutational analyses of the coding regions of GARS were performed using targeted sequencing of 54 patients with molecularly unassigned axonal CMT, who were selected from 340 unrelated CMT patients. Two heterozygous mutations in GARS, p.Asp146Tyr and p.Met238Arg, were identified; one in each patient. Both are novel de novo mutations. The p.Asp146Tyr mutation is associated with a severe infantile-onset neuropathy and the p.Met238Arg mutation results in childhood-onset disability.GARS mutations are an uncommon cause of CMT in Taiwan. The p.Asp146Tyr and p.Met238Arg mutations are associated with early-onset axonal CMT. These findings broaden the mutational spectrum of GARS and also highlight the importance of considering GARS mutations as a disease cause in patients with early-onset neuropathies.

  10. Two Novel De Novo GARS Mutations Cause Early-Onset Axonal Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Liao, Yi-Chu; Liu, Yo-Tsen; Tsai, Pei-Chien; Chang, Chia-Ching; Huang, Yen-Hua; Soong, Bing-Wen; Lee, Yi-Chung

    2015-01-01

    Mutations in the GARS gene have been identified in a small number of patients with Charcot-Marie-Tooth disease (CMT) type 2D or distal spinal muscular atrophy type V, for whom disease onset typically occurs during adolescence or young adulthood, initially manifesting as weakness and atrophy of the hand muscles. The role of GARS mutations in patients with inherited neuropathies in Taiwan remains elusive. Mutational analyses of the coding regions of GARS were performed using targeted sequencing of 54 patients with molecularly unassigned axonal CMT, who were selected from 340 unrelated CMT patients. Two heterozygous mutations in GARS, p.Asp146Tyr and p.Met238Arg, were identified; one in each patient. Both are novel de novo mutations. The p.Asp146Tyr mutation is associated with a severe infantile-onset neuropathy and the p.Met238Arg mutation results in childhood-onset disability. GARS mutations are an uncommon cause of CMT in Taiwan. The p.Asp146Tyr and p.Met238Arg mutations are associated with early-onset axonal CMT. These findings broaden the mutational spectrum of GARS and also highlight the importance of considering GARS mutations as a disease cause in patients with early-onset neuropathies.

  11. Treatment of chronic inflammatory neuropathies

    NARCIS (Netherlands)

    F. Eftimov

    2015-01-01

    This thesis focuses on the efficacy of existing and alternative treatments in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) and explores predictors of treatment response in patients with CIDP treated with corticosteroids. The efficacy of intra

  12. Axon density and axon orientation dispersion in children born preterm

    NARCIS (Netherlands)

    Kelly, Claire E.; Thompson, Deanne K.; Chen, Jian; Leemans, Alexander; Adamson, Christopher L.; Inder, Terrie E.; Cheong, Jeanie L Y; Doyle, Lex W.; Anderson, Peter J.

    2016-01-01

    Background Very preterm birth (VPT, <32 weeks' gestation) is associated with altered white matter fractional anisotropy (FA), the biological basis of which is uncertain but may relate to changes in axon density and/or dispersion, which can be measured using Neurite Orientation Dispersion and Density

  13. Organophosphate-induced delayed neuropathy: case report Neuropatia tardia por organofosforado: relato de caso

    Directory of Open Access Journals (Sweden)

    Luiz Felipe R Vasconcellos

    2002-12-01

    Full Text Available Organophosphate induced delayed neuropathy (OPIDN is an uncommon clinical condition. It occurs in association with the ingestion of great amounts of organophosphate after the stimulation of cholinergic receptor. The clinical picture is characterized by a distal paresis in lower limbs associated with sensitive symptoms. Electrodiagnostic studies show a motor axonal neuropathy. Involvement of the central nervous system may occur. We describe a 39 years-old female patient who developed hyperesthesia associated with lower limbs paresis, fourteen days after she had ingested a Dichlorvos-based insecticide. Electrophysiological study was characterized by an axonal polyneuropathy pattern. Pyramidal tract dysfunction was observed later in upper limbs. Considering that both peripheral and central nervous systems are involved we believe that the more appropriated term would be organophosphate induced delayed neuropathy (OPIDN instead of organophosphate induced delayed polyneuropathy (OPIDP.A neuropatia tardia dos organofosforados (NTOF é condição clinica incomum. Geralmente ocorre após a intoxicação aguda por organofosforados, seguindo-se a fase de hiperestimulação colinérgica. O quadro clínico é caracterizado por déficit motor distal nos membros inferiores associado a sintomas sensitivos. O estudo eletroneuromiográfico tem demonstrado padrão axonal motor na maioria dos casos. Podem ocorrer sinais de comprometimento do sistema nervoso central. Descrevemos o caso de uma paciente de 39 anos que ingeriu inseticida a base de Dichlorvos e quatorze dias após apresentou quadro de hiperestesia associado a paresia distal nos membros inferiores. Realizou eletroneuromiografia que se caracterizou por padrão compatível com polineuropatia axonal. Sinais piramidais, de aparecimento mais tardio, foram observados nos membros superiores. Diante do comprometimento do sistema nervoso periférico e central, também consideramos o termo neuropatia tardia por

  14. Action-potential modulation during axonal conduction.

    Science.gov (United States)

    Sasaki, Takuya; Matsuki, Norio; Ikegaya, Yuji

    2011-02-04

    Once initiated near the soma, an action potential (AP) is thought to propagate autoregeneratively and distribute uniformly over axonal arbors. We challenge this classic view by showing that APs are subject to waveform modulation while they travel down axons. Using fluorescent patch-clamp pipettes, we recorded APs from axon branches of hippocampal CA3 pyramidal neurons ex vivo. The waveforms of axonal APs increased in width in response to the local application of glutamate and an adenosine A(1) receptor antagonist to the axon shafts, but not to other unrelated axon branches. Uncaging of calcium in periaxonal astrocytes caused AP broadening through ionotropic glutamate receptor activation. The broadened APs triggered larger calcium elevations in presynaptic boutons and facilitated synaptic transmission to postsynaptic neurons. This local AP modification may enable axonal computation through the geometry of axon wiring.

  15. Novel systems for in vivo monitoring and microenvironmental investigations of diabetic neuropathy in a murine model.

    Science.gov (United States)

    Amit, Sharon; Yaron, Avraham

    2012-11-01

    Peripheral neuropathy is a devastating complication of diabetes conferring vast morbidity and mortality. Despite prolonged efforts to elucidate the mechanisms underlying diabetic related neuropathic phenomena and develop effective therapies, current treatment is for the most part glycemic control and symptomatic care. This is partially due to the intricate pathophysiology of diabetic neuropathy and the scarcity of valid experimental models. The aim of the study was to establish novel systems enabling monitoring and dissection of significant processes in the development of diabetic neuropathy. In a non-invasive in vivo model, two-photon microscopy is applied to evaluate mechanoreceptors (Meissner corpuscles) within an intact footpad of transgenic mice expressing a fluorescent neuronal tracer. By applying this advanced technology, which couples potent tissue penetration with superb resolution, we documented qualitative and quantitative diabetes-specific alterations in these sensory structures. Detection of such changes previously required laborious invasive histopathological techniques. In parallel, we present an ex vivo system that mimics the native microenvironment of the nerve ending via a unique co-culture of primary sensory neurons and thin skin slices. In conjunction with innovative high-throughput digital axonal measurements and computerized quantification tools, this method enables an unbiased exploration of neuronal autonomous and non-autonomous malfunctions. Using this setup we demonstrate that while the diabetic nerve retains a near-normal growth and regeneration capacities, the diabetic skin exhibits a decreased ability to support axonal outgrowth. Thus, an early target organ failure rather than intrinsic neuronal failure may initiate the neuropathy. Overall, the illustrated experimental platforms may greatly facilitate the holistic investigation of diabetic neuropathy.

  16. Peripheral Neuropathy in Spinocerebellar Ataxia Type 1, 2, 3, and 6.

    Science.gov (United States)

    Linnemann, Christoph; Tezenas du Montcel, Sophie; Rakowicz, Maryla; Schmitz-Hübsch, Tanja; Szymanski, Sandra; Berciano, Jose; van de Warrenburg, Bart P; Pedersen, Karine; Depondt, Chantal; Rola, Rafal; Klockgether, Thomas; García, Antonio; Mutlu, Gurkan; Schöls, Ludger

    2016-04-01

    Spinocerebellar ataxias (SCAs) are characterized by autosomal dominantly inherited progressive ataxia but are clinically heterogeneous due to variable involvement of non-cerebellar parts of the nervous system. Non-cerebellar symptoms contribute significantly to the burden of SCAs, may guide the clinician to the underlying genetic subtype, and might be useful markers to monitor disease. Peripheral neuropathy is frequently observed in SCA, but subtype-specific features and subclinical manifestations have rarely been evaluated. We performed a multicenter nerve conduction study with 162 patients with genetically confirmed SCA1, SCA2, SCA3, and SCA6. The study proved peripheral nerves to be involved in the neurodegenerative process in 82 % of SCA1, 63 % of SCA2, 55 % of SCA3, and 22 % of SCA6 patients. Most patients of all subtypes revealed affection of both sensory and motor fibers. Neuropathy was most frequently of mixed type with axonal and demyelinating characteristics in all SCA subtypes. However, nerve conduction velocities of SCA1 patients were slower compared to other genotypes. SCA6 patients revealed less axonal damage than patients with other subtypes. No influence of CAG repeat length or biometric determinants on peripheral neuropathy could be identified in SCA1, SCA3, and SCA6. In SCA2, earlier onset and more severe ataxia were associated with peripheral neuropathy. We proved peripheral neuropathy to be a frequent site of the neurodegenerative process in all common SCA subtypes. Since damage to peripheral nerves is readily assessable by electrophysiological means, nerve conduction studies should be performed in a longitudinal approach to assess these parameters as potential progression markers.

  17. Optofluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Ordonez, Simon; Black, Bryan; Mohanty, Samarendra K.

    2013-03-01

    Significant efforts are being made for control on axonal guidance due to its importance in nerve regeneration and in the formation of functional neuronal circuitry in-vitro. These include several physical (topographic modification, optical force, and electric field), chemical (surface functionalization cues) and hybrid (electro-chemical, photochemical etc) methods. Here, we report comparison of the effect of linear flow versus microfluidic flow produced by an opticallydriven micromotor in guiding retinal ganglion axons. A circularly polarized laser tweezers was used to hold, position and spin birefringent calcite particle near growth cone, which in turn resulted in microfluidic flow. The flow rate and resulting shear-force on axons could be controlled by a varying the power of the laser tweezers beam. The calcite particles were placed separately in one chamber and single particle was transported through microfluidic channel to another chamber containing the retina explant. In presence of flow, the turning of axons was found to strongly correlate with the direction of flow. Turning angle as high as 90° was achieved. Optofluidic-manipulation can be applied to other types of mammalian neurons and also can be extended to stimulate mechano-sensing neurons.

  18. Evaluation of cochleo-vestibular functions in patients with auditory neuropathy

    Directory of Open Access Journals (Sweden)

    Namea M. Ismail

    2014-07-01

    Conclusion: Patients with auditory neuropathy could also have vestibular neuropathy. Vestibular neuropathy could be classified into three groups: superior vestibular neuropathy, inferior vestibular neuropathy and superior/inferior vestibular neuropathy.

  19. Painful Charcot-Marie-Tooth neuropathy type 2E/1F due to a novel NEFL mutation.

    Science.gov (United States)

    Doppler, Kathrin; Kunstmann, Erdmute; Krüger, Stefan; Sommer, Claudia

    2017-05-01

    Charcot-Marie-Tooth neuropathy (CMT) 2E/1F is caused by mutations in the neurofilament light-chain polypeptide (NEFL) gene. Giant axons are a histological hallmark frequently seen in nerves of patients with CMT2E. We describe the case of a 43-year-old patient with a painful, predominantly sensory neuropathy. The patient's sural nerve biopsy showed multiple giant axons. Genetic sequencing of the NEFL gene revealed that the patient was heterozygous for an altered sequence of the gene, c.816C>G, p.Asn272Lys, which has not yet been described in CMT2E/1F. In contrast to other cases of CMT2E/1F, where motor symptoms are predominant, pain was the most disabling symptom in this patient. Muscle Nerve 55: 752-755, 2017. © 2016 Wiley Periodicals, Inc.

  20. Hypothyroidism: Can It Cause Peripheral Neuropathy?

    Science.gov (United States)

    Hypothyroidism: Can it cause peripheral neuropathy? Can hypothyroidism cause peripheral neuropathy and, if so, how is it treated? Answers from Todd B. Nippoldt, M.D. Hypothyroidism — a condition in which your ...

  1. Peripheral neuropathy: the importance of rare subtypes

    Science.gov (United States)

    Callaghan, Brian C.; Price, Ray S.; Chen, Kevin S.; Feldman, Eva L.

    2016-01-01

    Importance Peripheral neuropathy is a prevalent condition that usually warrants a thorough history and examination, but limited diagnostic evaluation. Rare localizations of peripheral neuropathy, however, often require more extensive diagnostic testing and different treatments. Objective To describe rare localizations of peripheral neuropathy, including the appropriate diagnostic evaluation and available treatments. Evidence Review References were identified from PubMed searches with an emphasis on systematic reviews and randomized clinical trials. Articles were also identified through the use of the author's own files. Search terms included common rare neuropathy localizations and their causes, as well as epidemiology, pathophysiology, diagnosis, and treatment. Findings Diffuse, non-length dependent neuropathies, multiple mononeuropathies, polyradiculopathies, plexopathies, and radiculoplexus neuropathies are rare peripheral neuropathy localizations that often require extensive diagnostic testing. Atypical neuropathy features, such as acute/subacute onset, asymmetry, and/or motor predominant signs, are frequently present. The most common diffuse, non-length dependent neuropathies are Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and amyotrophic lateral sclerosis (ALS). Effective disease modifying therapies exist for many diffuse, non-length dependent neuropathies including GBS, CIDP, MMN, and some paraprotein-associated demyelinating neuropathies. Vasculitic neuropathy (multiple mononeuropathy) also has efficacious treatment options, but definitive evidence of a treatment effect for IgM anti-MAG neuropathy and diabetic amyoptrophy (radiculoplexus neuropathy) is lacking. Conclusions and Relevance Recognition of rare localizations of periperhal neuropathy is essential given the implications for diagnostic testing and treatment. Electrodiagnostic studies are an important early step in the

  2. An update on electrophysiological studies in neuropathy

    DEFF Research Database (Denmark)

    Krarup, Christian

    2003-01-01

    The review concentrates on the use of clinical neurophysiology in peripheral nerve disorders covered in the present issue. It is pertinent to distinguish different types of involvement of fibers in diabetic neuropathy, including the involvement of small and large fibers, to outline the diagnostic...... criteria of inflammatory neuropathies, and to describe the spectrum of peripheral nerve pathophysiology in inherited neuropathies. Painful neuropathies represent a particular challenge to clinical neurophysiology since it is mainly small fibers, which are difficult to study, that are affected....

  3. [Diagnosis and treatment of multifocal motor neuropathy (Lewis-Sumner)].

    Science.gov (United States)

    Kaji, R

    1999-01-01

    We made a retrospective long-term follow-up study of 25 patients with multifocal motor neuropathy (Lewis-Sumner). The diagnosis was based upon criteria modified from those of AAEM (Sumner 1997). The electrophysiological findings indicating conduction block or focal demyelinative lesions were more diagnostic than anti-GM 1 antibody titers, which were elevated in only 40% of these patients. Demonstration of definite conduction block was not always possible in those patients who responded favorably to intravenous immunoglobulins (IVIg), whereas indirect pieces of evidence such as F-wave abnormalities or focal conduction delay or dispersion were equally helpful. IVIg had superior outcome to cyclophosphamide, which sometimes caused serious adverse effects. Three patients with severe axonal involvement showed elevated monospecific antibodies to GalNAc-GD1a.

  4. New Horizons in Diabetic Neuropathy: Mechanisms, Bioenergetics, and Pain

    DEFF Research Database (Denmark)

    Feldman, Eva L; Nave, Klaus-Armin; Jensen, Troels Staehelin

    2017-01-01

    the mechanisms underlying diabetic neuropathy (DN). In this review, we present the structural components of the peripheral nervous system that underlie its susceptibility to metabolic insults and then discuss the pathways that contribute to peripheral nerve injury in DN. We also discuss systems biology insights......Pre-diabetes and diabetes are a global epidemic, and the associated neuropathic complications create a substantial burden on both the afflicted patients and society as a whole. Given the enormity of the problem and the lack of effective therapies, there is a pressing need to understand...... gleaned from the recent advances in biotechnology and bioinformatics, emerging ideas centered on the axon-Schwann cell relationship and associated bioenergetic crosstalk, and the rapid expansion of our knowledge of the mechanisms contributing to neuropathic pain in diabetes. These recent advances in our...

  5. Behavioral and pharmacological characteristics of bortezomib-induced peripheral neuropathy in rats

    Directory of Open Access Journals (Sweden)

    Shota Yamamoto

    2015-09-01

    Full Text Available Bortezomib, an effective anticancer drug for multiple myeloma, often causes peripheral neuropathy which is mainly characterized by numbness and painful paresthesia. Nevertheless, there is no effective strategy to escape or treat bortezomib-induced peripheral neuropathy (BIPN, because we have understood few mechanism of this side effect. In this study, we evaluated behavioral and pathological characteristics of BIPN, and investigated pharmacological efficacy of various analgesic drugs and adjuvants on mechanical allodynia induced by bortezomib treatment in rats. The repeated administration of bortezomib induced mechanical and cold allodynia. There was axonal degeneration of sciatic nerve behind these neuropathic symptoms. Furthermore, the exposure to bortezomib shortened neurite length in PC12 cells. Finally, the result of evaluation of anti-allodynic potency, oral administration of tramadol (10 mg/kg, pregabalin (3 mg/kg, duloxetine (30 mg/kg or mexiletine (100 mg/kg, but not amitriptyline or diclofenac, transiently relieved the mechanical allodynia induced by bortezomib. These results suggest that axonal degeneration of the sciatic nerve is involved in BIPN and that some analgesic drugs and adjuvants are effective in the relief of painful neuropathy.

  6. P-ANCA vasculitic neuropathy with 12-year latency between onset of neuropathy and systemic symptoms

    Directory of Open Access Journals (Sweden)

    Greenberg Steven A

    2002-10-01

    Full Text Available Abstract Background The differential diagnosis of chronic progressive multifocal asymmetric neuropathies is challenging. Vasculitic neuropathies, multifocal forms of chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathies, and asymmetric lower motor neuron disorders are important considerations. Case presentation We report a patient with an unusually long 12-year course of nonsystemic vasculitic neuropathy prior to the development of systemic manifestations. Conclusion We discuss some of the difficulties involved in the diagnosis of chronic progressive multifocal asymmetric neuropathies.

  7. The Relationship between Dyslipidemia and Acute Axonal Function in Type 2 Diabetes Mellitus In Vivo.

    Science.gov (United States)

    Kwai, Natalie C G; Nigole, William; Poynten, Ann M; Brown, Christopher; Krishnan, Arun V

    2016-01-01

    Diabetic peripheral neuropathy (DPN) is a common and debilitating complication of diabetes mellitus. Treatment largely consists of symptom alleviation and there is a need to identify therapeutic targets for prevention and treatment of DPN. The objective of this study was to utilise novel neurophysiological techniques to investigate axonal function in patients with type 2 diabetes and to prospectively determine their relationship to serum lipids in type 2 diabetic patients. Seventy-one patients with type 2 diabetes were consecutively recruited and tested. All patients underwent thorough clinical neurological assessments including nerve conduction studies, and median motor axonal excitability studies. Studies were also undertaken in age matched normal control subjects(n = 42). Biochemical studies, including serum lipid levels were obtained in all patients. Patient excitability data was compared to control data and linear regression analysis was performed to determine the relationship between serum triglycerides and low density lipoproteins and excitability parameters typically abnormal in type 2 diabetic patients. Patient mean age was 64.2±2.3 years, mean glycosylated haemoglobin (HbA1c%) was 7.8±0.3%, mean triglyceride concentration was 1.6±0.1 mmol/L and mean cholesterol concentration was 4.1±0.2mmol/L. Compared to age matched controls, median motor axonal excitability studies indicated axonal dysfunction in type 2 diabetic patients as a whole (T2DM) and in a subgroup of the patients without DPN (T2DM-NN). These included reduced percentage threshold change during threshold electrotonus at 10-20ms depolarising currents (TEd10-20ms)(controls 68.4±0.8, T2DM63.9±0.8, T2DM-NN64.8±1.6%,Plipoprotein concentration when adjusted for renal function, a separate risk factor for neuropathy development. Our findings indicate that acutely, serum lipids do not exert an acute effect on axonal function in type 2 diabetic patients: TEd(10-20ms)(1.2(-1.4,3.8);P = 0.4) and

  8. [Small fibre neuropathy: knowledge is power].

    NARCIS (Netherlands)

    Hoeijmakers, J.G.; Bakkers, M.; Blom, E.W.; Drenth, J.P.H.; Merkies, I.S.; Faber, C.G.

    2012-01-01

    Small fibre neuropathy is a neuropathy of the small non-myelinated C-fibres and myelinated Adelta-fibres. Clinically, an isolated small fibre neuropathy is distinguished by sensory and autonomic symptoms, with practically no abnormalities on neurological examination other than possible distorted pai

  9. Study progression of painful diabetic neuropathy%糖尿病痛性神经病变的研究进展

    Institute of Scientific and Technical Information of China (English)

    金星

    2013-01-01

    糖尿病痛性神经病变(painful diabetic neuropathy,PDN)是一种感觉性周围神经病变.糖尿病神经病变的疼痛机制与初级感觉神经元和外周轴突通路的损伤产生过度兴奋和自发的异常放电相关.文中就PDN的病理机制、诊治进展进行综述.%Painful diabetic neuropathy (PDN) is a kind of sensory peripheral neuropathy. Hyperexcitability and aberrant spontaneous impulse generation by damaged first -order sensory neurons and their peripheral axons are well -established processes that strongly contribute to pain associated with diabetic neuropathy . This review describes the pathological mechanism , progression of diagnose and treatment of PDN.

  10. Neuronal activity in the hub of extrasynaptic Schwann cell-axon interactions

    Directory of Open Access Journals (Sweden)

    Chrysanthi eSamara

    2013-11-01

    Full Text Available The integrity and function of neurons depend on their continuous interactions with glial cells. In the peripheral nervous system glial functions are exerted by Schwann cells (SCs. SCs sense synaptic and extrasynaptic manifestations of action potential propagation and adapt their physiology to support neuronal activity. We review here existing literature data on extrasynaptic bidirectional axon-SC communication, focusing particularly on neuronal activity implications. To shed light on underlying mechanisms, we conduct a thorough analysis of microarray data from SC-rich mouse sciatic nerve at different developmental stages and in neuropathic models. We identify molecules that are potentially involved in SC detection of neuronal activity signals inducing subsequent glial responses. We further suggest that alterations in the activity-dependent axon-SC crosstalk impact on peripheral neuropathies. Together with previously reported data, these observations open new perspectives for deciphering glial mechanisms of neuronal function support.

  11. ALS5/SPG11/KIAA1840 mutations cause autosomal recessive axonal Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Montecchiani, Celeste; Pedace, Lucia; Lo Giudice, Temistocle; Casella, Antonella; Mearini, Marzia; Gaudiello, Fabrizio; Pedroso, José L; Terracciano, Chiara; Caltagirone, Carlo; Massa, Roberto; St George-Hyslop, Peter H; Barsottini, Orlando G P; Kawarai, Toshitaka; Orlacchio, Antonio

    2016-01-01

    Charcot-Marie-Tooth disease is a group of hereditary peripheral neuropathies that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, as well as diminished tendon reflexes. Hundreds of causative DNA changes have been found, but much of the genetic basis of the disease is still unexplained. Mutations in the ALS5/SPG11/KIAA1840 gene are a frequent cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and peripheral axonal neuropathy, and account for ∼ 40% of autosomal recessive juvenile amyotrophic lateral sclerosis. The overlap of axonal Charcot-Marie-Tooth disease with both diseases, as well as the common autosomal recessive inheritance pattern of thin corpus callosum and axonal Charcot-Marie-Tooth disease in three related patients, prompted us to analyse the ALS5/SPG11/KIAA1840 gene in affected individuals with autosomal recessive axonal Charcot-Marie-Tooth disease. We investigated 28 unrelated families with autosomal recessive axonal Charcot-Marie-Tooth disease defined by clinical, electrophysiological, as well as pathological evaluation. Besides, we screened for all the known genes related to axonal autosomal recessive Charcot-Marie-Tooth disease (CMT2A2/HMSN2A2/MFN2, CMT2B1/LMNA, CMT2B2/MED25, CMT2B5/NEFL, ARCMT2F/dHMN2B/HSPB1, CMT2K/GDAP1, CMT2P/LRSAM1, CMT2R/TRIM2, CMT2S/IGHMBP2, CMT2T/HSJ1, CMTRID/COX6A1, ARAN-NM/HINT and GAN/GAN), for the genes related to autosomal recessive hereditary spastic paraplegia with thin corpus callosum and axonal peripheral neuropathy (SPG7/PGN, SPG15/ZFYVE26, SPG21/ACP33, SPG35/FA2H, SPG46/GBA2, SPG55/C12orf65 and SPG56/CYP2U1), as well as for the causative gene of peripheral neuropathy with or without agenesis of the corpus callosum (SLC12A6). Mitochondrial disorders related to Charcot-Marie-Tooth disease type 2 were also excluded by sequencing POLG and TYMP genes. An additional locus for autosomal recessive Charcot

  12. Axonal Charcot-Marie-Tooth disease patient-derived motor neurons demonstrate disease-specific phenotypes including abnormal electrophysiological properties.

    Science.gov (United States)

    Saporta, Mario A; Dang, Vu; Volfson, Dmitri; Zou, Bende; Xie, Xinmin Simon; Adebola, Adijat; Liem, Ronald K; Shy, Michael; Dimos, John T

    2015-01-01

    Charcot-Marie-Tooth (CMT) disease is a group of inherited peripheral neuropathies associated with mutations or copy number variations in over 70 genes encoding proteins with fundamental roles in the development and function of Schwann cells and peripheral axons. Here, we used iPSC-derived cells to identify common pathophysiological mechanisms in axonal CMT. iPSC lines from patients with two distinct forms of axonal CMT (CMT2A and CMT2E) were differentiated into spinal cord motor neurons and used to study axonal structure and function and electrophysiological properties in vitro. iPSC-derived motor neurons exhibited gene and protein expression, ultrastructural and electrophysiological features of mature primary spinal cord motor neurons. Cytoskeletal abnormalities were found in neurons from a CMT2E (NEFL) patient and corroborated by a mouse model of the same NEFL point mutation. Abnormalities in mitochondrial trafficking were found in neurons derived from this patient, but were only mildly present in neurons from a CMT2A (MFN2) patient. Novel electrophysiological abnormalities, including reduced action potential threshold and abnormal channel current properties were observed in motor neurons derived from both of these patients. Human iPSC-derived motor neurons from axonal CMT patients replicated key pathophysiological features observed in other models of MFN2 and NEFL mutations, including abnormal cytoskeletal and mitochondrial dynamics. Electrophysiological abnormalities found in axonal CMT iPSC-derived human motor neurons suggest that these cells are hyperexcitable and have altered sodium and calcium channel kinetics. These findings may provide a new therapeutic target for this group of heterogeneous inherited neuropathies. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Peripheral neuropathy in mitochondrial disorders.

    Science.gov (United States)

    Pareyson, Davide; Piscosquito, Giuseppe; Moroni, Isabella; Salsano, Ettore; Zeviani, Massimo

    2013-10-01

    Why is peripheral neuropathy common but mild in many mitochondrial disorders, and why is it, in some cases, the predominant or only manifestation? Although this question remains largely unanswered, recent advances in cellular and molecular biology have begun to clarify the importance of mitochondrial functioning and distribution in the peripheral nerve. Mutations in proteins involved in mitochondrial dynamics (ie, fusion and fission) frequently result in a Charcot-Marie-Tooth phenotype. Peripheral neuropathies with different phenotypic presentations occur in mitochondrial diseases associated with abnormalities in mitochondrial DNA replication and maintenance, or associated with defects in mitochondrial respiratory chain complex V. Our knowledge of mitochondrial disorders is rapidly growing as new nuclear genes are identified and new phenotypes described. Early diagnosis of mitochondrial disorders, essential to provide appropriate genetic counselling, has become crucial in a few treatable conditions. Recognising and diagnosing an underlying mitochondrial defect in patients presenting with peripheral neuropathy is therefore of paramount importance.

  14. Entrapment neuropathies in diabetes mellitus

    Science.gov (United States)

    Rota, Eugenia; Morelli, Nicola

    2016-01-01

    Neuropathy is a common complication of diabetes mellitus (DM) with a wide clinical spectrum that encompasses generalized to focal and multifocal forms. Entrapment neuropathies (EN), which are focal forms, are so frequent at any stage of the diabetic disease, that they may be considered a neurophysiological hallmark of peripheral nerve involvement in DM. Indeed, EN may be the earliest neurophysiological abnormalities in DM, particularly in the upper limbs, even in the absence of a generalized polyneuropathy, or it may be superimposed on a generalized diabetic neuropathy. This remarkable frequency of EN in diabetes is underlain by a peculiar pathophysiological background. Due to the metabolic alterations consequent to abnormal glucose metabolism, the peripheral nerves show both functional impairment and structural changes, even in the preclinical stage, making them more prone to entrapment in anatomically constrained channels. This review discusses the most common and relevant EN encountered in diabetic patient in their epidemiological, pathophysiological and diagnostic features. PMID:27660694

  15. Entrapment neuropathies in diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Eugenia; Rota[1; Nicola; Morelli[1

    2016-01-01

    Neuropathy is a common complication of diabetes mellitus (DM) with a wide clinical spectrum that encompasses generalized to focal and multifocal forms. Entrapment neuropathies (EN), which are focal forms,are so frequent at any stage of the diabetic disease, that they may be considered a neurophysiological hallmark of peripheral nerve involvement in DM. Indeed, EN may be the earliest neurophysiological abnormalities in DM,particularly in the upper limbs, even in the absence of a generalized polyneuropathy, or it may be superimposed on a generalized diabetic neuropathy. This remarkable frequency of EN in diabetes is underlain by a peculiar pathophysiological background. Due to the metabolic alterations consequent to abnormal glucose metabolism, the peripheral nerves show both functional impairment and structural changes, even in the preclinical stage, making them more prone to entrapment in anatomically constrained channels. This review discusses the most common and relevant EN encountered in diabetic patient in their epidemiological, pathophysiological and diagnostic features.

  16. The Spectrum of Diabetic Neuropathies

    Science.gov (United States)

    Tracy, Jennifer A.; Dyck, P. James B.

    2009-01-01

    Diabetes mellitus is associated with many different neuropathic syndromes, ranging from a mild sensory disturbance as can be seen in a diabetic sensorimotor polyneuropathy, to the debilitating pain and weakness of a diabetic lumbosacral radiculoplexus neuropathy. The etiology of these syndromes has been extensively studied, and may vary among metabolic, compressive, and immunological bases for the different disorders, as well as mechanisms yet to be discovered. Many of these disorders of nerve appear to be separate conditions with different underlying mechanisms, and some are directly caused by diabetes mellitus, whereas others are associated with it but not caused by hyperglycemia. We discuss a number of the more common disorders of nerve found with diabetes mellitus. We discuss the symmetrical neuropathies, particularly generalized diabetic polyneuropathy, and then the focal or asymmetrical types of diabetes-associated neuropathy. PMID:18194747

  17. Human intraretinal myelination: Axon diameters and axon/myelin thickness ratios

    Directory of Open Access Journals (Sweden)

    Thomas FitzGibbon

    2013-01-01

    Full Text Available Purpose: Human intraretinal myelination of ganglion cell axons occurs in about 1% of the population. We examined myelin thickness and axon diameter in human retinal specimens containing myelinated retinal ganglion cell axons. Materials and Methods: Two eyes containing myelinated patches were prepared for electron microscopy. Two areas were examined in one retina and five in the second retina. Measurements were compared to normal retinal and optic nerve samples and the rabbit retina, which normally contains myelinated axons. Measurements were made using a graphics tablet. Results: Mean axon diameter of myelinated axons at all locations were significantly larger than unmyelinated axons (P ≤ 0.01. Myelinated axons within the patches were significantly larger than axons within the optic nerve (P < 0.01. The relationship between axon diameter/fiber diameter (the G-ratio seen in the retinal sites differed from that in the nerve. G-ratios were higher and myelin thickness was positively correlated to axon diameter (P < 0.01 in the retina but negatively correlated to axon diameter in the nerve (P < 0.001. Conclusion: Intraretinally myelinated axons are larger than non-myelinated axons from the same population and suggests that glial cells can induce diameter changes in retinal axons that are not normally myelinated. This effect is more dramatic on intraretinal axons compared with the normal transition zone as axons enter the optic nerve and these changes are abnormal. Whether intraretinal myelin alters axonal conduction velocity or blocks axonal conduction remains to be clarified and these issues may have different clinical outcomes.

  18. Mechanisms of action of IVIg and therapeutic considerations in the treatment of acute and chronic demyelinating neuropathies.

    Science.gov (United States)

    Dalakas, Marinos C

    2002-12-24

    Intravenous immunoglobulin (IVIg) is an immunomodulating agent that has multiple activities, including modulation of complement activation products, suppressing idiotypic antibody, saturating Fc receptors on macrophages, and suppressing various inflammatory mediators including cytokines, chemokines, and metalloproteinases. Because all these factors are implicated to various degrees in the pathogenesis of immune-mediated demyelination of the PNS, administration of IVIg could be beneficial in treating neuropathies by suppressing the immune-mediated processes that are directed against myelin or axonal antigenic targets. This article outlines the actions of IVIg in CIDP and other autoimmune neuropathies based on data derived from in vivo and in vitro studies. The predominant mechanisms by which IVIg exerts its action on these neuropathies appear to be a combined effect on complement inactivation, neutralization of idiotypic antibodies, cytokine inhibition, and saturation of Fc receptors on endoneurial macrophages.

  19. Analysis of dynein intermediate chains, light intermediate chains and light chains in a cohort of hereditary peripheral neuropathies.

    Science.gov (United States)

    Tey, Shelisa; Ahmad-Annuar, Azlina; Drew, Alexander P; Shahrizaila, Nortina; Nicholson, Garth A; Kennerson, Marina L

    2014-10-01

    The cytoplasmic dynein heavy chain (DYNC1H1) gene has been increasingly associated with neurodegenerative disorders including axonal Charcot-Marie-Tooth disease (CMT2), intellectual disability and malformations of cortical development. In addition, evidence from mouse models (Loa, catabolite repressor-activator (Cra) and Sprawling (Swl)) has shown that mutations in Dync1h1 cause a range of neurodegenerative phenotypes with motor and sensory neuron involvement. In this current study, we examined the possible contribution of other cytoplasmic dynein subunits that bind to DYNC1H1 as a cause of inherited peripheral neuropathy. We focused on screening the cytoplasmic dynein intermediate, light intermediate and light chain genes in a cohort of families with inherited peripheral neuropathies. Nine genes were screened and ten variants were detected, but none was identified as pathogenic, indicating that cytoplasmic dynein intermediate, light intermediate and light chains are not a cause of neuropathy in our cohort.

  20. Evidence of GLP-1-mediated neuroprotection in an animal model of pyridoxine-induced peripheral sensory neuropathy.

    Science.gov (United States)

    Perry, TracyAnn; Holloway, Harold W; Weerasuriya, Ananda; Mouton, Peter R; Duffy, Kara; Mattison, Julie A; Greig, Nigel H

    2007-02-01

    Pyridoxine (vitamin B6) intoxicated rodents develop a peripheral neuropathy characterized by sensory nerve conduction deficits associated with disturbances of nerve fiber geometry and axonal atrophy. To investigate the possibility that glucagon-like peptide-1 (7-36)-amide (GLP-1) receptor agonism may influence axonal structure and function through neuroprotection neurotrophic support, effects of GLP-1 and its long acting analog, Exendin-4 (Ex4) treatment on pyridoxine-induced peripheral neuropathy were examined in rats using behavioral and morphometric techniques. GLP-1 is an endogenous insulinotropic peptide secreted from the gut in response to the presence of food. GLP-1 receptors (GLP-1R) are coupled to the cAMP second messenger pathway, and are expressed widely throughout neural tissues of humans and rodents. Recent studies have established that GLP-1 and Ex4, have multiple synergistic effects on glucose-dependent insulin secretion pathways of pancreatic beta-cells and on neural plasticity. Data reported here suggest that clinically relevant doses of GLP-1 and Ex4 may offer some protection against the sensory peripheral neuropathy induced by pyridoxine. Our findings suggest a potential role for these peptides in the treatment of neuropathies, including that associated with type II diabetes mellitus.

  1. Disulfiram neuropathy: two case reports

    OpenAIRE

    2016-01-01

    Background Neuropathy is a rare adverse side effect of disulfiram therapy and is under-recognized. There have been few case reports documenting this side effect. Case presentation Two cases of disulfiram peripheral neuropathy are discussed. The first case is that of a 25-year-old Caucasian woman who was exposed to disulfiram therapy for a total of 8 months and developed pain and stiffness that prevented her from walking. The second case is that of a 46-year-old Caucasian woman who developed s...

  2. The EGR2 gene is involved in axonal Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Sevilla, T; Sivera, R; Martínez-Rubio, D; Lupo, V; Chumillas, M J; Calpena, E; Dopazo, J; Vílchez, J J; Palau, F; Espinós, C

    2015-12-01

    A three-generation family affected by axonal Charcot-Marie-Tooth disease (CMT) was investigated with the aim of discovering genetic defects and to further characterize the phenotype. The clinical, nerve conduction studies and muscle magnetic resonance images of the patients were reviewed. A whole exome sequencing was performed and the changes were investigated by genetic studies, in silico analysis and luciferase reporter assays. A novel c.1226G>A change (p.R409Q) in the EGR2 gene was identified. Patients presented with a typical, late-onset axonal CMT phenotype with variable severity that was confirmed in the ancillary tests. The in silico studies showed that the residue R409 is an evolutionary conserved amino acid. The p.R409Q mutation, which is predicted as probably damaging, would alter the conformation of the protein slightly and would cause a decrease of gene expression. This is the first report of an EGR2 mutation presenting as an axonal CMT phenotype with variable severity. This study broadens the phenotype of the EGR2-related neuropathies and suggests that the genetic testing of patients suffering from axonal CMT should include the EGR2 gene. © 2015 EAN.

  3. Dimethyl Fumarate Ameliorates Lewis Rat Experimental Autoimmune Neuritis and Mediates Axonal Protection.

    Directory of Open Access Journals (Sweden)

    Kalliopi Pitarokoili

    Full Text Available Dimethyl fumarate is an immunomodulatory and neuroprotective drug, approved recently for the treatment of relapsing-remitting multiple sclerosis. In view of the limited therapeutic options for human acute and chronic polyneuritis, we used the animal model of experimental autoimmune neuritis in the Lewis rat to study the effects of dimethyl fumarate on autoimmune inflammation and neuroprotection in the peripheral nervous system.Experimental autoimmune neuritis was induced by immunization with the neuritogenic peptide (amino acids 53-78 of P2 myelin protein. Preventive treatment with dimethyl fumarate given at 45 mg/kg twice daily by oral gavage significantly ameliorated clinical neuritis by reducing demyelination and axonal degeneration in the nerve conduction studies. Histology revealed a significantly lower degree of inflammatory infiltrates in the sciatic nerves. In addition, we detected a reduction of early signs of axonal degeneration through a reduction of amyloid precursor protein expressed in axons of the peripheral nerves. This reduction correlated with an increase of nuclear factor (erythroid derived 2-related factor 2 positive axons, supporting the neuroprotective potential of dimethyl fumarate. Furthermore, nuclear factor (erythroid derived 2-related factor 2 expression in Schwann cells was only rarely detected and there was no increase of Schwann cells death during EAN.We conclude that immunomodulatory and neuroprotective dimethyl fumarate may represent an innovative therapeutic option in human autoimmune neuropathies.

  4. Notch Signaling Inhibits Axon Regeneration

    OpenAIRE

    Bejjani, Rachid El; Hammarlund, Marc

    2012-01-01

    Many neurons have limited capacity to regenerate their axons after injury. Neurons in the mammalian CNS do not regenerate, and even neurons in the PNS often fail to regenerate to their former targets. This failure is likely due in part to pathways that actively restrict regeneration; however, only a few factors that limit regeneration are known. Here, using single-neuron analysis of regeneration in vivo, we show that Notch/lin-12 signaling inhibits the regeneration of mature C. elegans neuron...

  5. Non-length-dependent and length-dependent small-fiber neuropathies associated with tumor necrosis factor (TNF)-inhibitor therapy in patients with rheumatoid arthritis: expanding the spectrum of neurological disease associated with TNF-inhibitors.

    Science.gov (United States)

    Birnbaum, Julius; Bingham, Clifton O

    2014-04-01

    Small-fiber neuropathy causes severe burning pain, requires diagnostic approaches such as skin biopsy, and encompasses two subtypes based on distribution of neuropathic pain. Such biopsy-proven subtypes of small-fiber neuropathies have not been previously described as complications of tumor necrosis factor (TNF)-inhibitor therapy. We therefore characterized clinical and skin biopsy findings in three rheumatoid arthritis (RA) patients who developed small-fiber neuropathies associated with TNF-inhibitors. We also conducted a systematic review of the literature to characterize subtypes of neuropathies previously reported in association with TNF-inhibitor therapy. Two patients presented with a "non-length-dependent" small-fiber neuropathy, experiencing unorthodox patterns of burning pain affecting the face, torso, and proximal extremities. Abnormal skin biopsy findings were limited to the proximal thigh, which is a marker of proximal-most dorsal root ganglia degeneration. In contrast, one patient presented with a "length-dependent" small-fiber neuropathy, experiencing burning pain only in the feet. Abnormal skin biopsy findings were limited to the distal feet, which is a marker of distal-most axonal degeneration. One patient developed a small-fiber neuropathy in the context of TNF-inhibitor-induced lupus. In all patients, neuropathies occurred during TNF-inhibitor-induced remission of RA disease activity and improved on withdrawal of TNF-inhibitors. We describe a spectrum of small-fiber neuropathies not previously reported in association with TNF-inhibitor therapy, with clinical and skin biopsy findings suggestive of dorsal root ganglia as well as axonal degeneration. The development of small-fiber neuropathies during inactive joint disease and improvement of neuropathic pain upon withdrawal of TNF-inhibitor suggest a causative role of TNF-inhibitors. © 2013 Published by Elsevier Inc.

  6. Inflammation: therapeutic targets for diabetic neuropathy.

    Science.gov (United States)

    Zhou, Jiyin; Zhou, Shiwen

    2014-02-01

    There are still no approved treatments for the prevention or of cure of diabetic neuropathy, and only symptomatic pain therapies of variable efficacy are available. Inflammation is a cardinal pathogenic mechanism of diabetic neuropathy. The relationships between inflammation and the development of diabetic neuropathy involve complex molecular networks and processes. Herein, we review the key inflammatory molecules (inflammatory cytokines, adhesion molecules, chemokines) and pathways (nuclear factor kappa B, JUN N-terminal kinase) implicated in the development and progression of diabetic neuropathy. Advances in the understanding of the roles of these key inflammatory molecules and pathways in diabetic neuropathy will facilitate the discovery of the potential of anti-inflammatory approaches for the inhibition of the development of neuropathy. Specifically, many anti-inflammatory drugs significantly inhibit the development of different aspects of diabetic neuropathy in animal models and clinical trials.

  7. Ischaemic optic neuropathy.

    Directory of Open Access Journals (Sweden)

    Hayreh Sohan

    2000-01-01

    Full Text Available Ischaemic optic neuropathy is of two types: anterior (AION and posterior (PION, the first involving the optic nerve head (ONH and the second, the rest of the optic nerve. Pathogenetically AION and PION are very different diseases. AION represents an acute ischaemic disorder of the ONH supplied by the posterior ciliary artery (PCA, while PION has no specific location in the posterior part of the optic nerve and does not represent an ischaemic disorder of any definite artery. The most important step towards a logical understanding of the underlying causes, clinical features, pathogenesis and rational management of AION, is to understand the basic scientific issues involved; these are discussed in some detail. AION clinically is of two types: (1 that due to giant cell arteritis (arteritic AION: A-AION and (2 non-arteritic AION (NA-AION. NA-AION, the more common of the two, is one of the most prevalent and visually crippling diseases in the middle-aged and elderly, and is potentially bilateral. NA-AION is a multifactorial disease, with many risk factors collectively contributing to its development. Although there is no known treatment for NA-AION, reduction of risk factors is important in decreasing chances of involvement of the second eye and of further episodes. Our studies have suggested that nocturnal arterial hypotension is an important risk factor for the development and progression of NA-AION. The role of nocturnal arterial hypotension in the pathogenesis of NA-AION and management of nocturnal hypotension is discussed. Potent antihypertensive drugs, when used aggressively and/or given at bedtime, are emerging as an important risk factor for nocturnal hypotension, and there is some evidence that NA-AION may be occurring as an iatrogenic disease in some individuals. A-AION, by contrast, is an ocular emergency and requires immediate treatment with systemic corticosteroids to prevent further visual loss. The clinical parameters which help to

  8. Exacerbation of Charcot-Marie-Tooth type 2E neuropathy following traumatic nerve injury.

    Science.gov (United States)

    Villalón, Eric; Dale, Jeffrey M; Jones, Maria; Shen, Hailian; Garcia, Michael L

    2015-11-19

    Charcot-Marie-Tooth disease (CMT) is the most commonly inherited peripheral neuropathy. CMT disease signs include distal limb neuropathy, abnormal gait, sensory defects, and deafness. We generated a novel line of CMT2E mice expressing hNF-L(E397K), which displayed muscle atrophy of the lower limbs without denervation, proximal reduction in large caliber axons, and decreased nerve conduction velocity. In this study, we challenged wild type, hNF-L and hNF-L(E397K) mice with crush injury to the sciatic nerve. We analyzed functional recovery by measuring toe spread and analyzed gait using the Catwalk system. hNF-L(E397K) mice demonstrated reduced recovery from nerve injury consistent with increased susceptibility to neuropathy observed in CMT patients. In addition, hNF-L(E397K) developed a permanent reduction in their ability to weight bear, increased mechanical allodynia, and premature gait shift in the injured limb, which led to increasingly disrupted interlimb coordination in hNF-L(E397K). Exacerbation of neuropathy after injury and identification of gait alterations in combination with previously described pathology suggests that hNF-L(E397K) mice recapitulate many of clinical signs associated with CMT2. Therefore, hNF-L(E397K) mice provide a model for determining the efficacy of novel therapies.

  9. Tadalafil Promotes the Recovery of Peripheral Neuropathy in Type II Diabetic Mice.

    Science.gov (United States)

    Wang, Lei; Chopp, Michael; Szalad, Alexandra; Lu, XueRong; Jia, LongFei; Lu, Mei; Zhang, Rui Lan; Zhang, Zheng Gang

    2016-01-01

    We previously demonstrated that treatment of diabetic peripheral neuropathy with the short (4 hours) half-life phosphodiesterase 5 (PDE5) inhibitor, sildenafil, improved functional outcome in diabetic db/db mice. To further examine the effect of PDE5 inhibition on diabetic peripheral neuropathy, we investigated the effect of another potent PDE5 inhibitor, tadalafil, on diabetic peripheral neuropathy. Tadalafil is pharmacokinetically distinct from sildenafil and has a longer half-life (17+hours) than sildenafil. Diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 20 weeks were treated with tadalafil every 48 hours for 8 consecutive weeks. Compared with diabetic mice treated with saline, tadalafil treatment significantly improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal sensitivity. Tadalafil treatment also markedly increased local blood flow and the density of FITC-dextran perfused vessels in the sciatic nerve concomitantly with increased intraepidermal nerve fiber density. Moreover, tadalafil reversed the diabetes-induced reductions of axon diameter and myelin thickness and reversed the diabetes-induced increased g-ratio in the sciatic nerve. Furthermore, tadalafil enhanced diabetes-reduced nerve growth factor (NGF) and platelet-derived growth factor-C (PDGF-C) protein levels in diabetic sciatic nerve tissue. The present study demonstrates that tadalafil increases regional blood flow in the sciatic nerve tissue, which may contribute to the improvement of peripheral nerve function and the amelioration of diabetic peripheral neuropathy.

  10. Neuroinflammation in the peripheral nerve: Cause, modulator, or bystander in peripheral neuropathies?

    Science.gov (United States)

    2015-01-01

    The role of innate and adaptive inflammation as a primary driver or modifier of neuropathy in premorbidly normal nerves, and as a critical player in amplifying neuropathies of other known causes (e.g., genetic, metabolic) is incompletely understood and under‐researched, despite unmet clinical need. Also, cellular and humoral components of the adaptive and innate immune system are substantial disease modifying agents in the context of neuropathies and, at least in some neuropathies, there is an identified tight interrelationship between both compartments of the immune system. Additionally, the quadruple relationship between Schwann cell, axon, macrophage, and endoneurial fibroblast, with their diverse membrane bound and soluble signalling systems, forms a distinct focus for investigation in nerve diseases with inflammation secondary to Schwann cell mutations and possibly others. Identification of key immunological effector pathways that amplify neuropathic features and associated clinical symptomatology including pain should lead to realistic and timely possibilities for translatable therapeutic interventions using existing immunomodulators, alongside the development of novel therapeutic targets. GLIA 2016;64:475–486 PMID:26250643

  11. Sphingomyelin as a myelin biomarker in CSF of acquired demyelinating neuropathies.

    Science.gov (United States)

    Capodivento, Giovanna; Visigalli, Davide; Garnero, Martina; Fancellu, Roberto; Ferrara, Michela Demetra; Basit, Abdul; Hamid, Zeeshan; Pastore, Vito Paolo; Garibaldi, Silvano; Armirotti, Andrea; Mancardi, Gianluigi; Serrati, Carlo; Capello, Elisabetta; Schenone, Angelo; Nobbio, Lucilla

    2017-08-10

    Fast, accurate and reliable methods to quantify the amount of myelin still lack, both in humans and experimental models. The overall objective of the present study was to demonstrate that sphingomyelin (SM) in the cerebrospinal fluid (CSF) of patients affected by demyelinating neuropathies is a myelin biomarker. We found that SM levels mirror both peripheral myelination during development and small myelin rearrangements in experimental models. As in acquired demyelinating peripheral neuropathies myelin breakdown occurs, SM amount in the CSF of these patients might detect the myelin loss. Indeed, quantification of SM in 262 neurological patients showed a significant increase in patients with peripheral demyelination (p = 3.81 * 10 - 8) compared to subjects affected by non-demyelinating disorders. Interestingly, SM alone was able to distinguish demyelinating from axonal neuropathies and differs from the principal CSF indexes, confirming the novelty of this potential CSF index. In conclusion, SM is a specific and sensitive biomarker to monitor myelin pathology in the CSF of peripheral neuropathies. Most importantly, SM assay is simple, fast, inexpensive, and promising to be used in clinical practice and drug development.

  12. [Peripheral sensory neuropathy produced by a megadose of vitamin B6].

    Science.gov (United States)

    Ohnishi, A; Ishibashi, H; Ohtani, K; Matsunaga, K; Yamamoto, T

    1985-06-01

    Clinical cases of sensory neuropathy produced by a megadose of vitamin B6 have been reported in English literatures. We investigated the ordinary daily dosage and maximal dose of vitamin B6 widely adopted in Japan, and the amount of vitamin B6 per unit (per tablet, capsule or ampule) available in our medical practice. We concluded that in Japan it is very rare to administer such a large dose of vitamin B6 that produced sensory neuropathy described in the literatures. In our experimental study, Sprague-Dawley rats were intraperitoneally given a total amount of 14,000 mg/kg of body weight of pyridoxine hydrochloride in ten separate doses. They developed an ataxic gait. The occurrence of the degeneration of nerve cell bodies and peripheral axons of lumbar primary sensory neurons were histologically demonstrated. Although in Japan no clinical cases of neuropathy produced by a megadose of vitamin B6 have been reported to our knowledge, it is necessary to be aware of the possible occurrence of such neuropathy among patients with polyneuropathy of unknown etiology or who have been receiving vitamin B6 for a long time.

  13. Charcot-Marie-Tooth Disease and Related Hereditary Neuropathies: From Gene Function to Associated Phenotypes.

    Science.gov (United States)

    Pareyson, D; Saveri, P; Piscosquito, G

    2014-10-10

    Charcot-Marie-Tooth disease (CMT) and related neuropathies are a genetically highly heterogeneous group of neurodegenerative disorders. CMT affects both the sensory and motor nerves, distal Hereditary Motor Neuropathies (dHMN) are phenotypically similar disorders involving only motor nerves, while Hereditary Sensory and Autonomic Neuropathies (HSAN) are rare distinct disorders affecting sensory and sometimes autonomic nerves. Almost 70 genes have been identified as responsible for these disorders. It is astonishing to learn how diverse are the cellular sublocalisation and the functional roles of the encoded proteins of CMT-associated genes which all lead to similar disorders of the peripheral nervous system. Myelin formation and maintenance, mitochondrial dynamics, cytoskeleton organization, axonal transport, and vesicular trafficking are the most frequently involved pathways. However, dysfunction of several activities from the nucleus to the neuromuscular junction forms the basis for these hereditary neuropathies, making it challenging predicting the functions of newly identified mutated genes. In this review we will discuss the function and related phenotypes of all the genes thus far associated with CMT, dHMN, and HSAN.

  14. DNA testing in hereditary neuropathies.

    LENUS (Irish Health Repository)

    Murphy, Sinéad M

    2013-01-01

    The inherited neuropathies are a clinically and genetically heterogeneous group of disorders in which there have been rapid advances in the last two decades. Molecular genetic testing is now an integral part of the evaluation of patients with inherited neuropathies. In this chapter we describe the genes responsible for the primary inherited neuropathies. We briefly discuss the clinical phenotype of each of the known inherited neuropathy subgroups, describe algorithms for molecular genetic testing of affected patients and discuss genetic counseling. The basic principles of careful phenotyping, documenting an accurate family history, and testing the available genes in an appropriate manner should identify the vast majority of individuals with CMT1 and many of those with CMT2. In this chapter we also describe the current methods of genetic testing. As advances are made in molecular genetic technologies and improvements are made in bioinformatics, it is likely that the current time-consuming methods of DNA sequencing will give way to quicker and more efficient high-throughput methods, which are briefly discussed here.

  15. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neur...

  16. Optic neuropathy in familial dysautonomia.

    Science.gov (United States)

    Groom, M; Kay, M D; Corrent, G F

    1997-06-01

    Optic atrophy, which is indicative of a CNS disorder, is a rarely described manifestation of familial dysautonomia (Riley-Day syndrome). As these patients are now living longer, the prevalence of optic neuropathy also may be increasing. We present a man with familial dysautonomia and visual loss resulting from optic atrophy and visual field defect suggestive of chiasmal pathology.

  17. Molecular approach of auditory neuropathy.

    Science.gov (United States)

    Silva, Magali Aparecida Orate Menezes da; Piatto, Vânia Belintani; Maniglia, Jose Victor

    2015-01-01

    Mutations in the otoferlin gene are responsible for auditory neuropathy. To investigate the prevalence of mutations in the mutations in the otoferlin gene in patients with and without auditory neuropathy. This original cross-sectional case study evaluated 16 index cases with auditory neuropathy, 13 patients with sensorineural hearing loss, and 20 normal-hearing subjects. DNA was extracted from peripheral blood leukocytes, and the mutations in the otoferlin gene sites were amplified by polymerase chain reaction/restriction fragment length polymorphism. The 16 index cases included nine (56%) females and seven (44%) males. The 13 deaf patients comprised seven (54%) males and six (46%) females. Among the 20 normal-hearing subjects, 13 (65%) were males and seven were (35%) females. Thirteen (81%) index cases had wild-type genotype (AA) and three (19%) had the heterozygous AG genotype for IVS8-2A-G (intron 8) mutation. The 5473C-G (exon 44) mutation was found in a heterozygous state (CG) in seven (44%) index cases and nine (56%) had the wild-type allele (CC). Of these mutants, two (25%) were compound heterozygotes for the mutations found in intron 8 and exon 44. All patients with sensorineural hearing loss and normal-hearing individuals did not have mutations (100%). There are differences at the molecular level in patients with and without auditory neuropathy. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  18. Mitochondrial dynamics in peripheral neuropathies.

    Science.gov (United States)

    Sajic, Marija

    2014-08-01

    Mitochondrial dynamics describes the continuous change in the position, size, and shape of mitochondria within cells. The morphological and functional complexity of neurons, the remarkable length of their processes, and the rapid changes in metabolic requirements arising from their intrinsic excitability render these cells particularly dependent on effective mitochondrial function and positioning. The rules that govern these changes and their functional significance are not fully understood, yet the dysfunction of mitochondrial dynamics has been implicated as a pathogenetic factor in a number of diseases, including disorders of the central and peripheral nervous systems. In recent years, a number of mutations of genes encoding proteins that play important roles in mitochondrial dynamics and function have been discovered in patients with Charcot-Marie-Tooth (CMT) disease, a hereditary peripheral neuropathy. These findings have directly linked mitochondrial pathology to the pathology of peripheral nerve and have identified certain aspects of mitochondrial dynamics as potential early events in the pathogenesis of CMT. In addition, mitochondrial dysfunction has now been implicated in the pathogenesis of noninherited neuropathies, including diabetic and inflammatory neuropathies. The role of mitochondria in peripheral nerve diseases has been mostly examined in vitro, and less so in animal models. This review examines available evidence for the role of mitochondrial dynamics in the pathogenesis of peripheral neuropathies, their relevance in human diseases, and future challenges for research in this field.

  19. DNA testing in hereditary neuropathies.

    Science.gov (United States)

    Murphy, Sinéad M; Laurá, Matilde; Reilly, Mary M

    2013-01-01

    The inherited neuropathies are a clinically and genetically heterogeneous group of disorders in which there have been rapid advances in the last two decades. Molecular genetic testing is now an integral part of the evaluation of patients with inherited neuropathies. In this chapter we describe the genes responsible for the primary inherited neuropathies. We briefly discuss the clinical phenotype of each of the known inherited neuropathy subgroups, describe algorithms for molecular genetic testing of affected patients and discuss genetic counseling. The basic principles of careful phenotyping, documenting an accurate family history, and testing the available genes in an appropriate manner should identify the vast majority of individuals with CMT1 and many of those with CMT2. In this chapter we also describe the current methods of genetic testing. As advances are made in molecular genetic technologies and improvements are made in bioinformatics, it is likely that the current time-consuming methods of DNA sequencing will give way to quicker and more efficient high-throughput methods, which are briefly discussed here. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Pyridoxine-Induced Sensory Neuropathy

    OpenAIRE

    1995-01-01

    An 18-year-old man with seizures from birth was followed in the Department of Clinical Neurological Sciences, University of Western Ontario, London, and was found to have developed a sensory neuropathy by 2 years of age following treatment with pyridoxine in doses up to 2000 mg/day.

  1. Molecular approach of auditory neuropathy

    Directory of Open Access Journals (Sweden)

    Magali Aparecida Orate Menezes da Silva

    2015-06-01

    Full Text Available INTRODUCTION: Mutations in the otoferlin gene are responsible for auditory neuropathy. OBJECTIVE: To investigate the prevalence of mutations in the mutations in the otoferlin gene in patients with and without auditory neuropathy. METHODS: This original cross-sectional case study evaluated 16 index cases with auditory neuropathy, 13 patients with sensorineural hearing loss, and 20 normal-hearing subjects. DNA was extracted from peripheral blood leukocytes, and the mutations in the otoferlin gene sites were amplified by polymerase chain reaction/restriction fragment length polymorphism. RESULTS: The 16 index cases included nine (56% females and seven (44% males. The 13 deaf patients comprised seven (54% males and six (46% females. Among the 20 normal-hearing subjects, 13 (65% were males and seven were (35% females. Thirteen (81% index cases had wild-type genotype (AA and three (19% had the heterozygous AG genotype for IVS8-2A-G (intron 8 mutation. The 5473C-G (exon 44 mutation was found in a heterozygous state (CG in seven (44% index cases and nine (56% had the wild-type allele (CC. Of these mutants, two (25% were compound heterozygotes for the mutations found in intron 8 and exon 44. All patients with sensorineural hearing loss and normal-hearing individuals did not have mutations (100%. CONCLUSION: There are differences at the molecular level in patients with and without auditory neuropathy.

  2. Hereditary sensory neuropathy type I

    Directory of Open Access Journals (Sweden)

    Auer-Grumbach Michaela

    2008-03-01

    Full Text Available Abstract Hereditary sensory neuropathy type I (HSN I is a slowly progressive neurological disorder characterised by prominent predominantly distal sensory loss, autonomic disturbances, autosomal dominant inheritance, and juvenile or adulthood disease onset. The exact prevalence is unknown, but is estimated as very low. Disease onset varies between the 2nd and 5th decade of life. The main clinical feature of HSN I is the reduction of sensation sense mainly distributed to the distal parts of the upper and lower limbs. Variable distal muscle weakness and wasting, and chronic skin ulcers are characteristic. Autonomic features (usually sweating disturbances are invariably observed. Serious and common complications are spontaneous fractures, osteomyelitis and necrosis, as well as neuropathic arthropathy which may even necessitate amputations. Some patients suffer from severe pain attacks. Hypacusis or deafness, or cough and gastrooesophageal reflux have been observed in rare cases. HSN I is a genetically heterogenous condition with three loci and mutations in two genes (SPTLC1 and RAB7 identified so far. Diagnosis is based on the clinical observation and is supported by a family history. Nerve conduction studies confirm a sensory and motor neuropathy predominantly affecting the lower limbs. Radiological studies, including magnetic resonance imaging, are useful when bone infections or necrosis are suspected. Definitive diagnosis is based on the detection of mutations by direct sequencing of the SPTLC1 and RAB7 genes. Correct clinical assessment and genetic confirmation of the diagnosis are important for appropriate genetic counselling and prognosis. Differential diagnosis includes the other hereditary sensory and autonomic neuropathies (HSAN, especially HSAN II, as well as diabetic foot syndrome, alcoholic neuropathy, neuropathies caused by other neurotoxins/drugs, immune mediated neuropathy, amyloidosis, spinal cord diseases, tabes dorsalis, lepra

  3. Lifestyle risk factors for ulnar neuropathy and ulnar neuropathy-like symptoms

    DEFF Research Database (Denmark)

    Frost, Poul; Johnsen, Birger; Fuglsang-Frederiksen, Anders;

    2013-01-01

    Introduction: We examined whether lifestyle factors differ between patients with ulnar neuropathy confirmed by electroneurography (ENG) and those with ulnar neuropathy-like symptoms with normal ulnar nerve ENG. Methods: Among patients examined by ENG for suspected ulnar neuropathy, we identified...... 546 patients with ulnar neuropathy and 633 patients with ulnar neuropathy-like symptoms. These groups were compared with 2 separate groups of matched community referents and to each other. Questionnaire information on lifestyle was obtained. The electrophysiological severity of neuropathy was also...

  4. [Clinical practice of hereditary motor neuropathy (HMN) and hereditary sensory and autonomic neuropathy (HSAN)].

    Science.gov (United States)

    Takashima, Hiroshi

    2014-01-01

    Inherited neuropathy is a genetically and clinically heterogeneous group of neuropathies, the main category becomes Charcot-Marie-Tooth neuropathy (CMT), also known as hereditary motor and sensory neuropathy (HMSN), distal hereditary motor neuropathy (dHMN), and hereditary sensory autonomic neuropathy (HSAN). At least 80 genes have been associated with CMT, HMN or HSAN, a precise molecular diagnosis is often needed to make a clinical diagnosis accurately, enable genetic counseling of the patient and understanding of their molecular mechanisms. To identify the mutation in each patient, using a high-throughput NGS, we established a diagnostic procedure involving screening of disease causing genes in CMT, HMN or HSAN.

  5. Human Genetic Disorders of Axon Guidance

    Science.gov (United States)

    Engle, Elizabeth C.

    2010-01-01

    This article reviews symptoms and signs of aberrant axon connectivity in humans, and summarizes major human genetic disorders that result, or have been proposed to result, from defective axon guidance. These include corpus callosum agenesis, L1 syndrome, Joubert syndrome and related disorders, horizontal gaze palsy with progressive scoliosis, Kallmann syndrome, albinism, congenital fibrosis of the extraocular muscles type 1, Duane retraction syndrome, and pontine tegmental cap dysplasia. Genes mutated in these disorders can encode axon growth cone ligands and receptors, downstream signaling molecules, and axon transport motors, as well as proteins without currently recognized roles in axon guidance. Advances in neuroimaging and genetic techniques have the potential to rapidly expand this field, and it is feasible that axon guidance disorders will soon be recognized as a new and significant category of human neurodevelopmental disorders. PMID:20300212

  6. Exenatide Facilitates Recovery from Oxaliplatin-Induced Peripheral Neuropathy in Rats.

    Directory of Open Access Journals (Sweden)

    Shunsuke Fujita

    Full Text Available Oxaliplatin has widely been used as a key drug in the treatment of colorectal cancer; however, it causes peripheral neuropathy. Exenatide, a glucagon-like peptide-1 (GLP-1 agonist, is an incretin mimetic secreted from ileal L cells, which is clinically used to treat type 2 diabetes mellitus. GLP-1 receptor agonists have been reported to exhibit neuroprotective effects on the central and peripheral nervous systems. In this study, we investigated the effects of exenatide on oxaliplatin-induced neuropathy in rats and cultured cells.Oxaliplatin (4 mg/kg was administered intravenously twice per week for 4 weeks, and mechanical allodynia was evaluated using the von Frey test in rats. Axonal degeneration was assessed by toluidine blue staining of sciatic nerves.Repeated administration of oxaliplatin caused mechanical allodynia from day 14 to 49. Although the co-administration of extended-release exenatide (100 μg/kg could not inhibit the incidence of oxaliplatin-induced mechanical allodynia, it facilitated recovery from the oxaliplatin-induced neuropathy with reparation of axonal degeneration. Inhibition of neurite outgrowth was evaluated in cultured pheochromocytoma 12 (PC12 cells. Exenatide inhibited oxaliplatin-induced neurite degeneration, but did not affect oxaliplatin-induced cell injury in cultured PC12 cells. Additionally, extended-release exenatide had no effect on the anti-tumor activity of oxaliplatin in cultured murine colon adenocarcinoma 26 (C-26 cells or C-26 cell-implanted mice.These results suggest that exenatide may be useful for treating peripheral neuropathy induced by oxaliplatin in colorectal cancer patients with type 2 diabetes.

  7. Akt Regulates Axon Wrapping and Myelin Sheath Thickness in the PNS

    Science.gov (United States)

    Baloui, Hasna; Meng, Xiaosong; Zhang, Yanqing; Deinhardt, Katrin; Dupree, Jeff L.; Einheber, Steven; Chrast, Roman

    2016-01-01

    uncertain. This work reveals that Akt controls several key steps of the PNS myelination. First, its activity promotes membrane production and axonal wrapping independent of a transcriptional effect. In myelinated axons, it also enhances myelin thickness through the mTOR pathway. Finally, sustained Akt activation in Schwann cells leads to hypermyelination/dysmyelination, mimicking some features present in neuropathies, such as hereditary neuropathy with liability to pressure palsies or demyelinating forms of Charcot-Marie-Tooth disease. Together, these data demonstrate the role of Akt in regulatory mechanisms underlying axonal wrapping and myelination in the PNS. PMID:27098694

  8. Mouse mtDNA mutant model of Leber hereditary optic neuropathy.

    Science.gov (United States)

    Lin, Chun Shi; Sharpley, Mark S; Fan, Weiwei; Waymire, Katrina G; Sadun, Alfredo A; Carelli, Valerio; Ross-Cisneros, Fred N; Baciu, Peter; Sung, Eric; McManus, Meagan J; Pan, Billy X; Gil, Daniel W; Macgregor, Grant R; Wallace, Douglas C

    2012-12-04

    An animal model of Leber hereditary optic neuropathy (LHON) was produced by introducing the human optic atrophy mtDNA ND6 P25L mutation into the mouse. Mice with this mutation exhibited reduction in retinal function by elecroretinogram (ERG), age-related decline in central smaller caliber optic nerve fibers with sparing of larger peripheral fibers, neuronal accumulation of abnormal mitochondria, axonal swelling, and demyelination. Mitochondrial analysis revealed partial complex I and respiration defects and increased reactive oxygen species (ROS) production, whereas synaptosome analysis revealed decreased complex I activity and increased ROS but no diminution of ATP production. Thus, LHON pathophysiology may result from oxidative stress.

  9. Evaluation and Prevention of Diabetic Neuropathy

    Directory of Open Access Journals (Sweden)

    Pajouhi M

    2007-07-01

    Full Text Available Background: Diabetic neuropathy is an incapacitating disease that afflicts almost 50 percent of patients with diabetes. A late finding in type 1 diabetes, diabetic neuropathy can be an early finding in non insulin-dependent diabetes. Diabetic neuropathies are divided primarily into two groups, sensorimotor and autonomic. Patients may acquire only one type of diabetic neuropathy or may present with combinations of neuropathies, such as autonomic neuropathy or distal symmetric polyneuropathy, the latter of which the most common form. Motor deficits, orthostatic hypotension, silent cardiac ischemia, hyperhidrosis, vasomotor instability, gastroparesis, bladder dysfunction, and sexual dysfunction can also result from diabetic neuropathy. Strict control of blood sugar, combined with proper daily foot care, is essential to avoid the complications of this disorder. With the potential to afflict any part of the nervous system, diabetic neuropathy should be suspected in all patients with type 2 diabetes as well as patients who have had type 1 diabetes for over five years. Although some patients with diabetic neuropathy notice few symptoms, upon physical examination mild to moderately severe sensory loss may be noted by the physician. Idiopathic neuropathy has been known to precede the onset of type 2 diabetes.

  10. AxonSeg: Open Source Software for Axon and Myelin Segmentation and Morphometric Analysis.

    Science.gov (United States)

    Zaimi, Aldo; Duval, Tanguy; Gasecka, Alicja; Côté, Daniel; Stikov, Nikola; Cohen-Adad, Julien

    2016-01-01

    Segmenting axon and myelin from microscopic images is relevant for studying the peripheral and central nervous system and for validating new MRI techniques that aim at quantifying tissue microstructure. While several software packages have been proposed, their interface is sometimes limited and/or they are designed to work with a specific modality (e.g., scanning electron microscopy (SEM) only). Here we introduce AxonSeg, which allows to perform automatic axon and myelin segmentation on histology images, and to extract relevant morphometric information, such as axon diameter distribution, axon density and the myelin g-ratio. AxonSeg includes a simple and intuitive MATLAB-based graphical user interface (GUI) and can easily be adapted to a variety of imaging modalities. The main steps of AxonSeg consist of: (i) image pre-processing; (ii) pre-segmentation of axons over a cropped image and discriminant analysis (DA) to select the best parameters based on axon shape and intensity information; (iii) automatic axon and myelin segmentation over the full image; and (iv) atlas-based statistics to extract morphometric information. Segmentation results from standard optical microscopy (OM), SEM and coherent anti-Stokes Raman scattering (CARS) microscopy are presented, along with validation against manual segmentations. Being fully-automatic after a quick manual intervention on a cropped image, we believe AxonSeg will be useful to researchers interested in large throughput histology. AxonSeg is open source and freely available at: https://github.com/neuropoly/axonseg.

  11. AxonSeg: open source software for axon and myelin segmentation and morphometric analysis

    Directory of Open Access Journals (Sweden)

    Aldo Zaimi

    2016-08-01

    Full Text Available Segmenting axon and myelin from microscopic images is relevant for studying the peripheral and central nervous system and for validating new MRI techniques that aim at quantifying tissue microstructure. While several software packages have been proposed, their interface is sometimes limited and/or they are designed to work with a specific modality (e.g., scanning electron microscopy only. Here we introduce AxonSeg, which allows to perform automatic axon and myelin segmentation on histology images, and to extract relevant morphometric information, such as axon diameter distribution, axon density and the myelin g-ratio. AxonSeg includes a simple and intuitive MATLAB-based graphical user interface and can easily be adapted to a variety of imaging modalities. The main steps of AxonSeg consist of: (i image pre-processing, (ii pre-segmentation of axons over a cropped image and discriminant analysis to select the best parameters based on axon shape and intensity information, (iii automatic axon and myelin segmentation over the full image and (iv atlas-based statistics to extract morphometric information. Segmentation results from standard optical microscopy (OM, scanning electron microscopy (SEM and coherent anti-Stokes Raman scattering (CARS microscopy are presented, along with validation against manual segmentations. Being fully-automatic after a quick manual intervention on a cropped image, we believe AxonSeg will be useful to researchers interested in large throughput histology. AxonSeg is open source and freely available at: https://github.com/neuropoly/axonseg.

  12. Misclassification and linkage of hereditary sensory and autonomic neuropathy type 1 as Charcot-Marie-Tooth disease, Type 2B

    Energy Technology Data Exchange (ETDEWEB)

    Vance, J.M.; Speer, M.C.; Stajich, J.M. [Duke Univ. Medical Center, Durham, NC (United States)

    1996-07-01

    Recently Kwon et al. published in the Journal their work describing linkage of a single large family with an inherited axonal neuropathy to chromosome 3, which they suggest is a second locus for Charcot-Marie-Tooth (CMT) type 2 and subsequently named {open_quotes}CMT2B.{close_quotes} We think that the diagnostic classification of this family as CMT2 is incorrect, since the subjects have a severe sensory neuropathy that fits within the hereditary sensory and autonomic neuropathy (HSAN) type 1 classification of Dyck (1993). Abnormal sensory findings in CMT2 separate it from distal spinal muscular atrophy but are a minor component of clinical symptoms in most CMT patients, as CMT is primarily a motor neuropathy. When Kwon et al. state that {open_quotes}all [patients] had characteristic findings in their physical examinations, including... evidence of foot sores that were slow to heal, or amputated limbs related to the poorly healing foot ulcers,{close_quotes} it suggests that a different diagnosis is more appropriate. In our experience collecting data on >950 individuals in >60 CMT1, CMT2, CMTX and CMT4 families, we have not seen foot ulcers, osteomyelitis, or amputations. Ulcerations leading to osteomyelitis and amputations are usually associated with severe sensory neuropathies. 16 refs., 1 tab.

  13. Mitochondrial optic neuropathies – Disease mechanisms and therapeutic strategies

    Science.gov (United States)

    Yu-Wai-Man, Patrick; Griffiths, Philip G.; Chinnery, Patrick F.

    2011-01-01

    Leber hereditary optic neuropathy (LHON) and autosomal-dominant optic atrophy (DOA) are the two most common inherited optic neuropathies in the general population. Both disorders share striking pathological similarities, marked by the selective loss of retinal ganglion cells (RGCs) and the early involvement of the papillomacular bundle. Three mitochondrial DNA (mtDNA) point mutations; m.3460G>A, m.11778G>A, and m.14484T>C account for over 90% of LHON cases, and in DOA, the majority of affected families harbour mutations in the OPA1 gene, which codes for a mitochondrial inner membrane protein. Optic nerve degeneration in LHON and DOA is therefore due to disturbed mitochondrial function and a predominantly complex I respiratory chain defect has been identified using both in vitro and in vivo biochemical assays. However, the trigger for RGC loss is much more complex than a simple bioenergetic crisis and other important disease mechanisms have emerged relating to mitochondrial network dynamics, mtDNA maintenance, axonal transport, and the involvement of the cytoskeleton in maintaining a differential mitochondrial gradient at sites such as the lamina cribosa. The downstream consequences of these mitochondrial disturbances are likely to be influenced by the local cellular milieu. The vulnerability of RGCs in LHON and DOA could derive not only from tissue-specific, genetically-determined biological factors, but also from an increased susceptibility to exogenous influences such as light exposure, smoking, and pharmacological agents with putative mitochondrial toxic effects. Our concept of inherited mitochondrial optic neuropathies has evolved over the past decade, with the observation that patients with LHON and DOA can manifest a much broader phenotypic spectrum than pure optic nerve involvement. Interestingly, these phenotypes are sometimes clinically indistinguishable from other neurodegenerative disorders such as Charcot-Marie-Tooth disease, hereditary spastic

  14. Axonal interferon responses and alphaherpesvirus neuroinvasion

    Science.gov (United States)

    Song, Ren

    Infection by alphaherpesviruses, including herpes simplex virus (HSV) and pseudorabies virus (PRV), typically begins at a peripheral epithelial surface and continues into the peripheral nervous system (PNS) that innervates this tissue. Inflammatory responses are induced at the infected peripheral site prior to viral invasion of the PNS. PNS neurons are highly polarized cells with long axonal processes that connect to distant targets. When the peripheral tissue is first infected, only the innervating axons are exposed to this inflammatory milieu, which include type I interferon (e.g. IFNbeta) and type II interferon (i.e. IFNgamma). IFNbeta can be produced by all types of cells, while IFNgamma is secreted by some specific types of immune cells. And both types of IFN induce antiviral responses in surrounding cells that express the IFN receptors. The fundamental question is how do PNS neurons respond to the inflammatory milieu experienced only by their axons. Axons must act as potential front-line barriers to prevent PNS infection and damage. Using compartmented cultures that physically separate neuron axons from cell bodies, I found that pretreating isolated axons with IFNbeta or IFNgamma significantly diminished the number of HSV-1 and PRV particles moving from axons to the cell bodies in an IFN receptor-dependent manner. Furthermore, I found the responses in axons are activated differentially by the two types of IFNs. The response to IFNbeta is a rapid, axon-only response, while the response to IFNgamma involves long distance signaling to the PNS cell body. For example, exposing axons to IFNbeta induced STAT1 phosphorylation (p-STAT1) only in axons, while exposure of axons to IFNgamma induced p-STAT1 accumulation in distant cell body nuclei. Blocking transcription in cell bodies eliminated IFNgamma-, but not IFNbeta-mediated antiviral effects. Proteomic analysis of IFNbeta- or IFNgamma-treated axons identified several differentially regulated proteins. Therefore

  15. Neuropathies optiques héréditaires

    DEFF Research Database (Denmark)

    Milea, D; Verny, C

    2012-01-01

    Hereditary optic neuropathies are a group of heterogeneous conditions affecting both optic nerves, with an autosomal dominant, autosomal recessive, X-related or mitochondrial transmission. The two most common non-syndromic hereditary optic neuropathies (Leber's hereditary optic neuropathy...

  16. Cardiovascular autonomic neuropathy in diabetes

    DEFF Research Database (Denmark)

    Spallone, Vincenza; Ziegler, Dan; Freeman, Roy

    2011-01-01

    Cardiovascular Autonomic Neuropathy (CAN) Subcommittee of Toronto Consensus Panel on Diabetic Neuropathy worked to update CAN guidelines, with regard to epidemiology, clinical impact, diagnosis, usefulness of CAN testing, and management. CAN is the impairment of cardiovascular autonomic control i....... Evidence on the cost-effectiveness of CAN testing is lacking. Apart from the preventive role of intensive glycaemic control in type 1 diabetes, recommendations cannot be given for most therapeutic approaches to CAN. Copyright © 2011 John Wiley & Sons, Ltd....... in the setting of diabetes after exclusion of other causes. The prevalence of confirmed CAN is around 20%, and increases up to 65% with age and diabetes duration. Established risk factors for CAN are glycaemic control in type 1 and a combination of hypertension, dyslipidemia, obesity and glycaemic control...

  17. New Generation Antidepressants in Painful Diabetic Neuropathy

    OpenAIRE

    Gutiérrez-Álvarez, Ángela-María; Carlos B. Moreno

    2011-01-01

    The incidence of diabetic neuropathy increases with the duration of diabetes and the degree of hyperglycaemia. Pain is one of the most common and incapacitating symptoms of diabetic neuropathy and its pharmacological control is complex. The effectiveness of antidepressive agents has been described in different types of neuropathic pain, but their effectiveness, when used as analgesics in painful diabetic neuropathy, still remains controversial. Objective: To review the possible role of new-ge...

  18. Differential calcium signaling mediated by voltage-gated calcium channels in rat retinal ganglion cells and their unmyelinated axons.

    Directory of Open Access Journals (Sweden)

    Allison Sargoy

    Full Text Available Aberrant calcium regulation has been implicated as a causative factor in the degeneration of retinal ganglion cells (RGCs in numerous injury models of optic neuropathy. Since calcium has dual roles in maintaining homeostasis and triggering apoptotic pathways in healthy and injured cells, respectively, investigation of voltage-gated Ca channel (VGCC regulation as a potential strategy to reduce the loss of RGCs is warranted. The accessibility and structure of the retina provide advantages for the investigation of the mechanisms of calcium signalling in both the somata of ganglion cells as well as their unmyelinated axons. The goal of the present study was to determine the distribution of VGCC subtypes in the cell bodies and axons of ganglion cells in the normal retina and to define their contribution to calcium signals in these cellular compartments. We report L-type Ca channel α1C and α1D subunit immunoreactivity in rat RGC somata and axons. The N-type Ca channel α1B subunit was in RGC somata and axons, while the P/Q-type Ca channel α1A subunit was only in the RGC somata. We patch clamped isolated ganglion cells and biophysically identified T-type Ca channels. Calcium imaging studies of RGCs in wholemounted retinas showed that selective Ca channel antagonists reduced depolarization-evoked calcium signals mediated by L-, N-, P/Q- and T-type Ca channels in the cell bodies but only by L-type Ca channels in the axons. This differential contribution of VGCC subtypes to calcium signals in RGC somata and their axons may provide insight into the development of target-specific strategies to spare the loss of RGCs and their axons following injury.

  19. The Spectrum of Diabetic Neuropathies

    OpenAIRE

    Tracy, Jennifer A.; Dyck, P. James B.

    2008-01-01

    Diabetes mellitus is associated with many different neuropathic syndromes, ranging from a mild sensory disturbance as can be seen in a diabetic sensorimotor polyneuropathy, to the debilitating pain and weakness of a diabetic lumbosacral radiculoplexus neuropathy. The etiology of these syndromes has been extensively studied, and may vary among metabolic, compressive, and immunological bases for the different disorders, as well as mechanisms yet to be discovered. Many of these disorders of nerv...

  20. Vincristine-Induced Cranial Neuropathy

    Directory of Open Access Journals (Sweden)

    Ahmad TALEBIAN*

    2013-12-01

    Full Text Available How to Cite This Article: Talebian A, Goudarzi RM, Mohammadzadeh M , Mirzadeh AS. Vincristine-Induced Cranial Neuropathy. Iran J Child Neurol. 2014 Winter; 8(1:66-68. Abstract Vincristine (VCR is a vinca alkaloid that is used for treatment of many malignancies. The vinca alkaloids are neurotoxic, usually causing a peripheral neuropathy, but cranial neuropathies are rare as side effects. Described here is the case of a 2.5-year-old boy, a known case of Wilms’ tumor, treated by vincristine (0/067 mg/kg/day and dactinomycin (0/045 mg/kg/day after surgery. Three weeks after treatment, he presented with bilateral ptosis. Neurological examination revealed bilateral ptosis with normal pupillary reflex and eye movement. He received 3.015 mg cumulative dose of vincristine before development of ptosis. Treatment with pyridoxine (150 mg/m2 p.o. BID and pyridostigmine (3 mg/kg p.o. BID started as neuroprotective agents, and after 7 days the problem disappeared. The treatment continued for 6 weeks and there were no signs of ptosis or a recurrence in follow up 2 months later.

  1. Imaging of neuropathies about the hip

    Energy Technology Data Exchange (ETDEWEB)

    Martinoli, Carlo, E-mail: carlo.martinoli@unige.it [Radiologia – DISC, Università di Genova, Largo Rosanna Benzi 8, I-16132 Genoa (Italy); Miguel-Perez, Maribel [Unit of Human Anatomy and Embryology, Department of Pathology and Experimental Therapy, Faculty of Medicine (C Bellvitge), University of Barcelona, Barcelona (Spain); Padua, Luca [Fondazione Don Gnocchi Onlus and Department of Neurology, Policlinico “A. Gemelli”, Università Cattolica del Sacro Cuore, Rome (Italy); Gandolfo, Nicola [IM2S – Institut Monégasque de Médecine and Chirurgie Sportive, Montecarlo (Monaco); Zicca, Anna [Radiologia – DISC, Università di Genova, Largo Rosanna Benzi 8, I-16132 Genoa (Italy); Tagliafico, Alberto [Radiologia – National Institute for Cancer Research, Genoa (Italy)

    2013-01-15

    Neuropathies about the hip may be cause of chronic pain and disability. In most cases, these conditions derive from mechanical or dynamic compression of a segment of a nerve within a narrow osteofibrous tunnel, an opening in a fibrous structure, or a passageway close to a ligament or a muscle. Although the evaluation of nerve disorders primarily relies on neurological examination and electrophysiology, diagnostic imaging is currently used as a complement to help define the site and aetiology of nerve compression and exclude other disease possibly underlying the patient’ symptoms. Diagnosis of entrapment neuropathies about the hip with US and MR imaging requires an in-depth knowledge of the normal imaging anatomy and awareness of the anatomic and pathologic factors that may predispose or cause a nerve injury. Accordingly, the aim of this article is to provide a comprehensive review of hip neuropathies with an emphasis on the relevant anatomy, aetiology, clinical presentation, and their imaging appearance. The lateral femoral cutaneous neuropathy (meiralgia paresthetica), femoral neuropathy, sciatic neuropathy, obturator neuropathy, superior and inferior gluteal neuropathies and pudendal neuropathy will be discussed.

  2. Sensory neuropathies, from symptoms to treatment.

    Science.gov (United States)

    Botez, Stephan A; Herrmann, David N

    2010-10-01

    The present review focuses on recent developments in diagnosis and treatment of sensory neuropathies. It does not seek to establish a comprehensive classification of sensory neuropathies, nor treatment guidelines per se. Diagnostic criteria and guidelines have been developed for distal symmetric polyneuropathies, small fiber sensory neuropathies and sensory neuronopathies. Novel diagnostic tools such as skin biopsies now allow diagnosis of small fiber sensory neuropathies. Genetic testing has defined new subtypes of mitochondrial neuropathies and inherited neuropathies with sensory involvement. Intravenous immunoglobulin and tumor necrosis factor-alpha inhibitors show promise for some dysimmune sensory neuropathies or neuronopathies. Additional options for management of neuropathic pain are emerging. Diagnostic methods for both acquired and hereditary sensory neuropathies have progressed in recent years, leading to earlier and more specific diagnoses and a better understanding of disease mechanisms. Much progress remains to be made regarding symptomatic and disease-modifying therapy for a range of sensory neuropathies, including those due to diabetes, HIV infection and from dysimmune or hereditary causes.

  3. Motor axon excitability during Wallerian degeneration

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez, Susana; Krarup, Christian

    2008-01-01

    , action potential propagation and structural integrity of the distal segment are maintained. The aim of this study was to investigate in vivo the changes in membrane function of motor axons during the 'latent' phase of Wallerian degeneration. Multiple indices of axonal excitability of the tibial nerve...

  4. Cable energy function of cortical axons.

    Science.gov (United States)

    Ju, Huiwen; Hines, Michael L; Yu, Yuguo

    2016-01-01

    Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na(+)-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na(+)-counting method severely underestimates energy cost in the cable model by 20-70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship.

  5. Commissural axons of the mouse cochlear nucleus.

    Science.gov (United States)

    Brown, M Christian; Drottar, Marie; Benson, Thane E; Darrow, Keith

    2013-05-01

    The axons of commissural neurons that project from one cochlear nucleus to the other were studied after labeling with anterograde tracer. Injections were made into the dorsal subdivision of the cochlear nucleus in order to restrict labeling only to the group of commissural neurons that gave off collaterals to, or were located in, this subdivision. The number of labeled commissural axons in each injection was correlated with the number of labeled radiate multipolar neurons, suggesting radiate neurons as the predominant origin of the axons. The radiate commissural axons are thick and myelinated, and they exit the dorsal acoustic stria of the injected cochlear nucleus to cross the brainstem in the dorsal half, near the crossing position of the olivocochlear bundle. They enter the opposite cochlear nucleus via the dorsal and ventral acoustic stria and at its medial border. Reconstructions of single axons demonstrate that terminations are mostly in the core and typically within a single subdivision of the cochlear nucleus. Extents of termination range from narrow to broad along both the dorsoventral (i.e., tonotopic) and the rostrocaudal dimensions. In the electron microscope, labeled swellings form synapses that are symmetric (in that there is little postsynaptic density), a characteristic of inhibitory synapses. Our labeled axons do not appear to include excitatory commissural axons that end in edge regions of the nucleus. Radiate commissural axons could mediate the broadband inhibition observed in responses to contralateral sound, and they may balance input from the two ears with a quick time course.

  6. Axon reflexes in human cold exposed fingers

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ducharme, M.B.

    2000-01-01

    Exposure of fingers to severe cold induces cold induced vasodilation (CIVD). The mechanism of CIVD is still debated. The original theory states that an axon reflex causes CIVD. To test this hypothesis, axon reflexes were evoked by electrical stimulation of the middle fingers of hands immersed in

  7. Axon reflexes in human cold exposed fingers

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ducharme, M.B.

    2000-01-01

    Exposure of fingers to severe cold induces cold induced vasodilation (CIVD). The mechanism of CIVD is still debated. The original theory states that an axon reflex causes CIVD. To test this hypothesis, axon reflexes were evoked by electrical stimulation of the middle fingers of hands immersed in wat

  8. Ascending Midbrain Dopaminergic Axons Require Descending GAD65 Axon Fascicles for Normal Pathfinding

    Directory of Open Access Journals (Sweden)

    Claudia Marcela Garcia-Peña

    2014-06-01

    Full Text Available The Nigrostriatal pathway (NSP is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.

  9. Comparison of electrophysiological findings in axonal and demyelinating Guillain-Barre syndrome.

    Directory of Open Access Journals (Sweden)

    Samira Yadegari

    2014-09-01

    Full Text Available Incidence and predominant subtype of Guillain-Barre syndrome (GBS differs geographically. Electrophysiology has an important role in early diagnosis and prediction of prognosis. This study is conducted to determine the frequent subtype of GBS in a large group of patients in Iran and compare nerve conduction studies in axonal and demyelinating forms of GBS.We retrospectively evaluated the medical records and electrodiagnostic study (EDS of 121 GBS patients who were managed in our hospital during 11 years. After regarding the exclusion criteria, patients classified as three groups: acute inflammatory demyelinating polyneuropathy (AIDP, acute motor axonal neuropathy (AMAN, and acute motor sensory axonal neuropathy (AMSAN. The most frequent subtype and then electrophysiological characteristic based on the time of EDS and their cerebrospinal fluid (CSF profile were assessed.Among 70 patients finally included in the study, 67% were men. About 63%, 23%, and 14% had AIDP, AMAN, and AMSAN, respectively. AIDP patients represented a wider range of ages compared with other groups. Higher levels of CSF protein, abnormal late responses and sural sparing were more frequent in AIDP subtype. Five AMSAN patients also revealed sural sparing. Conduction block (CB was observed in one AMAN patient. Prolonged F-wave latency was observed only in AIDP cases. CB and inexcitable sensory nerves were more frequent after 2 weeks, but reduced F-wave persistency was more prominent in the early phase.AIDP was the most frequent subtype. Although the electrophysiology and CSF are important diagnostic tools, classification should not be made based on a distinct finding.

  10. Comparison of electrophysiological findings in axonal and demyelinating Guillain-Barre syndrome

    Science.gov (United States)

    Yadegari, Samira; Nafissi, Shahriar; Kazemi, Neda

    2014-01-01

    Background: Incidence and predominant subtype of Guillain-Barre syndrome (GBS) differs geographically. Electrophysiology has an important role in early diagnosis and prediction of prognosis. This study is conducted to determine the frequent subtype of GBS in a large group of patients in Iran and compare nerve conduction studies in axonal and demyelinating forms of GBS. Methods: We retrospectively evaluated the medical records and electrodiagnostic study (EDS) of 121 GBS patients who were managed in our hospital during 11 years. After regarding the exclusion criteria, patients classified as three groups: acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor sensory axonal neuropathy (AMSAN). The most frequent subtype and then electrophysiological characteristic based on the time of EDS and their cerebrospinal fluid (CSF) profile were assessed. Results: Among 70 patients finally included in the study, 67% were men. About 63%, 23%, and 14% had AIDP, AMAN, and AMSAN, respectively. AIDP patients represented a wider range of ages compared with other groups. Higher levels of CSF protein, abnormal late responses and sural sparing were more frequent in AIDP subtype. Five AMSAN patients also revealed sural sparing. Conduction block (CB) was observed in one AMAN patient. Prolonged F-wave latency was observed only in AIDP cases. CB and inexcitable sensory nerves were more frequent after 2 weeks, but reduced F-wave persistency was more prominent in the early phase. Conclusion: AIDP was the most frequent subtype. Although the electrophysiology and CSF are important diagnostic tools, classification should not be made based on a distinct finding. PMID:25422732

  11. Dynamics of mitochondrial transport in axons

    Directory of Open Access Journals (Sweden)

    Robert Francis Niescier

    2016-05-01

    Full Text Available The polarized structure and long neurites of neurons pose a unique challenge for proper mitochondrial distribution. It is widely accepted that mitochondria move from the cell body to axon ends and vice versa; however, we have found that mitochondria originating from the axon ends moving in the retrograde direction never reach to the cell body, and only a limited number of mitochondria moving in the anterograde direction from the cell body arrive at the axon ends of mouse hippocampal neurons. Furthermore, we have derived a mathematical formula using the Fokker-Planck equation to characterize features of mitochondrial transport, and the equation could determine altered mitochondrial transport in axons overexpressing parkin. Our analysis will provide new insights into the dynamics of mitochondrial transport in axons of normal and unhealthy neurons.

  12. Early events in axon/dendrite polarization.

    Science.gov (United States)

    Cheng, Pei-lin; Poo, Mu-ming

    2012-01-01

    Differentiation of axons and dendrites is a critical step in neuronal development. Here we review the evidence that axon/dendrite formation during neuronal polarization depends on the intrinsic cytoplasmic asymmetry inherited by the postmitotic neuron, the exposure of the neuron to extracellular chemical factors, and the action of anisotropic mechanical forces imposed by the environment. To better delineate the functions of early signals among a myriad of cellular components that were shown to influence axon/dendrite formation, we discuss their functions by distinguishing their roles as determinants, mediators, or modulators and consider selective degradation of these components as a potential mechanism for axon/dendrite polarization. Finally, we examine whether these early events of axon/dendrite formation involve local autocatalytic activation and long-range inhibition, as postulated by Alan Turing for the morphogenesis of patterned biological structure.

  13. Immunotherapy Prospects for Painful Small-fiber Sensory Neuropathies and Ganglionopathies.

    Science.gov (United States)

    Oaklander, Anne Louise

    2016-01-01

    The best-known peripheral neuropathies are those affecting the large, myelinated motor and sensory fibers. These have well-established immunological causes and therapies. Far less is known about the somatic and autonomic "small fibers"; the unmyelinated C-fibers, thinly myelinated A-deltas, and postganglionic sympathetics. The small fibers sense pain and itch, innervate internal organs and tissues, and modulate the inflammatory and immune responses. Symptoms of small-fiber neuropathy include chronic pain and itch, sensory impairment, edema, and skin color, temperature, and sweating changes. Small-fiber polyneuropathy (SFPN) also causes cardiovascular, gastrointestinal, and urological symptoms, the neurologic origin of which often remains unrecognized. Routine electrodiagnostic study does not detect SFPN, so skin biopsies immunolabeled to reveal axons are recommended for diagnostic confirmation. Preliminary evidence suggests that dysimmunity causes some cases of small-fiber neuropathy. Several autoimmune diseases, including Sjögren and celiac, are associated with painful small-fiber ganglionopathy and distal axonopathy, and some patients with "idiopathic" SFPN have evidence of organ-specific dysimmunity, including serological markers. Dysimmune SFPN first came into focus in children and teenagers as they lack other risk factors, for example diabetes or toxic exposures. In them, the rudimentary evidence suggests humoral rather than cellular mechanisms and complement consumption. Preliminary evidence supports efficacy of corticosteroids and immunoglobulins in carefully selected children and adult patients. This paper reviews the evidence of immune causality and the limited data regarding immunotherapy for small-fiber-predominant ganglionitis, regional neuropathy (complex regional pain syndrome), and distal SFPN. These demonstrate the need to develop case definitions and outcome metrics to improve diagnosis, enable prospective trials, and dissect the mechanisms of

  14. Mutations in the MORC2 gene cause axonal Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Sevilla, Teresa; Lupo, Vincenzo; Martínez-Rubio, Dolores; Sancho, Paula; Sivera, Rafael; Chumillas, María J; García-Romero, Mar; Pascual-Pascual, Samuel I; Muelas, Nuria; Dopazo, Joaquín; Vílchez, Juan J; Palau, Francesc; Espinós, Carmen

    2016-01-01

    Charcot-Marie-Tooth disease (CMT) is a complex disorder with wide genetic heterogeneity. Here we present a new axonal Charcot-Marie-Tooth disease form, associated with the gene microrchidia family CW-type zinc finger 2 (MORC2). Whole-exome sequencing in a family with autosomal dominant segregation identified the novel MORC2 p.R190W change in four patients. Further mutational screening in our axonal Charcot-Marie-Tooth disease clinical series detected two additional sporadic cases, one patient who also carried the same MORC2 p.R190W mutation and another patient that harboured a MORC2 p.S25L mutation. Genetic and in silico studies strongly supported the pathogenicity of these sequence variants. The phenotype was variable and included patients with congenital or infantile onset, as well as others whose symptoms started in the second decade. The patients with early onset developed a spinal muscular atrophy-like picture, whereas in the later onset cases, the initial symptoms were cramps, distal weakness and sensory impairment. Weakness and atrophy progressed in a random and asymmetric fashion and involved limb girdle muscles, leading to a severe incapacity in adulthood. Sensory loss was always prominent and proportional to disease severity. Electrophysiological studies were consistent with an asymmetric axonal motor and sensory neuropathy, while fasciculations and myokymia were recorded rather frequently by needle electromyography. Sural nerve biopsy revealed pronounced multifocal depletion of myelinated fibres with some regenerative clusters and occasional small onion bulbs. Morc2 is expressed in both axons and Schwann cells of mouse peripheral nerve. Different roles in biological processes have been described for MORC2. As the silencing of Charcot-Marie-Tooth disease genes have been associated with DNA damage response, it is tempting to speculate that a deregulation of this pathway may be linked to the axonal degeneration observed in MORC2 neuropathy, thus adding a

  15. Rituximab Improves Subclinical Temporal Dispersion of Distal Compound Muscle Action Potential in Anti-MAG/SGPG Neuropathy Associated with Waldenström Macroglobulinemia: A Case Report

    Directory of Open Access Journals (Sweden)

    Kanji Yamamoto

    2013-02-01

    Full Text Available Patients with anti-myelin-associated glycoprotein (MAG/sulfated glucuronyl paragloboside (SGPG neuropathy associated with Waldenström macroglobulinemia show demyelinating neuropathy, but the temporal dispersion of distal compound muscle action potential (CMAP in motor nerve conduction studies (NCS, which represents heterogeneous demyelination at the motor nerve terminal, is rare. We report on a 70-year-old man with anti-MAG/SGPG neuropathy associated with Waldenström macroglobulinemia; he had a 2-year history of mild dysesthesia of the foot sole without any motor symptoms. He showed marked temporal dispersion of distal CMAP in the tibial nerve with other demyelinating findings in the NCS. The temporal dispersion of distal CMAP in the tibial nerve improved significantly, and motor function was again normal 1 year after rituximab monotherapy. The temporal dispersion of distal CMAP in anti-MAG/SGPG neuropathy is rare, but it could occur from an early stage when the patients show mild or no motor symptoms. Rituximab therapy before secondary axonal degeneration has great potential to reverse the effects of the demyelination including the temporal dispersion of distal CMAP, and to prevent the deterioration of neuropathy in anti-MAG/SGPG neuropathy.

  16. GDAP1 mutations in Italian axonal Charcot-Marie-Tooth patients: Phenotypic features and clinical course.

    Science.gov (United States)

    Pezzini, I; Geroldi, A; Capponi, S; Gulli, R; Schenone, A; Grandis, M; Doria-Lamba, L; La Piana, C; Cremonte, M; Pisciotta, C; Nolano, M; Manganelli, F; Santoro, L; Mandich, P; Bellone, E

    2016-01-01

    Mutations in the ganglioside-induced differentiation associated-protein 1 (GDAP1) gene have been associated with both autosomal recessive (AR) and dominant (AD) Charcot-Marie-Tooth (CMT) axonal neuropathy. The relative frequency of heterozygous, dominant mutations in Italian CMT is unknown. We investigated the frequency of dominant mutations in GDAP1 in a cohort of 109 axonal Italian patients by sequencing genomic DNA and search for copy number variations. We also explored correlations with clinical features. All cases had already been tested for variants in common axonal AD genes. Eight patients (7.3%) harbored five already reported heterozygous mutations in GDAP1 (p.Arg120Gly, p.Arg120Trp, p.His123Arg, p.Gln218Glu, p.Arg226Ser). Mutations had different penetrances in the families; the onset of symptoms is in the first decade and progression is slower than usually seen in GDAP1-related AR-CMT. We show that the relative frequency of mutations in GDAP was slightly higher than those observed in MFN2 and MPZ (7.3% vs 6.3% and 5.0%). The relatively milder clinical features and the quite indolent course observed are relevant for prognostic assessment. On the basis of our experience and the data reported here, we suggest GDAP1 as the first gene that should be analysed in Italian patients affected by CMT2.

  17. Progressive axonopathy: an inherited neuropathy of boxer dogs. 2. The nature and distribution of the pathological changes.

    Science.gov (United States)

    Griffiths, I R; McCulloch, M C; Abrahams, S

    1985-01-01

    This report describes the neuropathology of progressive axonopathy (PA), an autosomal recessive inherited neuropathy of Boxer dogs, which affects CNS and PNS. The nerve roots contain numerous myelin bubbles and proximal paranodal axonal swellings containing vesicles, vesiculo-tubular profiles and disorganized neurofilaments. The myelin sheath overlying such swellings is often attenuated. As the disease develops there are progressive changes in the myelin sheath with thinning at paranodal and internodal locations, loss of myelin from lengths of axon and the formation of short internodes with disproportionately thin sheaths. The abnormalities show a very definite selectivity for nerve roots and proximal nerves. Conversely, the frequency of degeneration and regeneration is greater distally except in the cervical ventral roots which contain numerous regenerating clusters. In the CNS numerous axonal spheroids are found in the lateral and ventral columns of the spinal cord and in various brain stem nuclei, particularly the superior olives, accessory cuneate nuclei and lateral lemniscus and its nucleus. Axonal degeneration which occurs mainly in the cord shows no obvious tract or proximal/distal selectivity. The optic pathways are also involved, predominantly adjacent to the chiasma. The autonomic nervous system is affected and distal limb muscles show varying, but usually minor, degrees of neurogenic atrophy. The condition, which has no obvious direct parallel in human or veterinary medicine, shows gross disturbances of axon-glial inter-relationships in both CNS and PNS.

  18. [A case or Leber hereditary optic neuropathy (LHON): differential diagnosis with post inflammatory atrophy of nerve II using the mtDNA analysis].

    Science.gov (United States)

    Lubos, Leszek; Wajgt, Andrzej; Maciejowski, Maciej; Mroczek-Tońska, Katarzyna; Bartnik, Ewa; Dziekanowska, Danuta

    2003-01-01

    The Leber hereditary optic neuropathy (LHON) is a disease due to a mtDNA mutation. The disorder results from enzymatic perturbations in the mitochondrial respiratory chain. Clinically the LHON may present as a progressive axonal atrophy of the optic nerves with or without other neurological symptoms. The process of reaching the diagnosis of the LHON by means of the molecular analysis of mtDNA is discussed.

  19. Developmental downregulation of LIS1 expression limits axonal extension and allows axon pruning

    Directory of Open Access Journals (Sweden)

    Kanako Kumamoto

    2017-07-01

    Full Text Available The robust axonal growth and regenerative capacities of young neurons decrease substantially with age. This developmental downregulation of axonal growth may facilitate axonal pruning and neural circuit formation but limits functional recovery following nerve damage. While external factors influencing axonal growth have been extensively investigated, relatively little is known about the intrinsic molecular changes underlying the age-dependent reduction in regeneration capacity. We report that developmental downregulation of LIS1 is responsible for the decreased axonal extension capacity of mature dorsal root ganglion (DRG neurons. In contrast, exogenous LIS1 expression or endogenous LIS1 augmentation by calpain inhibition restored axonal extension capacity in mature DRG neurons and facilitated regeneration of the damaged sciatic nerve. The insulator protein CTCF suppressed LIS1 expression in mature DRG neurons, and this reduction resulted in excessive accumulation of phosphoactivated GSK-3β at the axon tip, causing failure of the axonal extension. Conversely, sustained LIS1 expression inhibited developmental axon pruning in the mammillary body. Thus, LIS1 regulation may coordinate the balance between axonal growth and pruning during maturation of neuronal circuits.

  20. Laser-based single-axon transection for high-content axon injury and regeneration studies.

    Directory of Open Access Journals (Sweden)

    Darío Kunik

    Full Text Available The investigation of the regenerative response of the neurons to axonal injury is essential to the development of new axoprotective therapies. Here we study the retinal neuronal RGC-5 cell line after laser transection, demonstrating that the ability of these cells to initiate a regenerative response correlates with axon length and cell motility after injury. We show that low energy picosecond laser pulses can achieve transection of unlabeled single axons in vitro and precisely induce damage with micron precision. We established the conditions to achieve axon transection, and characterized RGC-5 axon regeneration and cell body response using time-lapse microscopy. We developed an algorithm to analyze cell trajectories and established correlations between cell motility after injury, axon length, and the initiation of the regeneration response. The characterization of the motile response of axotomized RGC-5 cells showed that cells that were capable of repair or regrowth of damaged axons migrated more slowly than cells that could not. Moreover, we established that RGC-5 cells with long axons could not recover their injured axons, and such cells were much more motile. The platform we describe allows highly controlled axonal damage with subcellular resolution and the performance of high-content screening in cell cultures.

  1. Axon Death Pathways Converge on Axundead to Promote Functional and Structural Axon Disassembly.

    Science.gov (United States)

    Neukomm, Lukas J; Burdett, Thomas C; Seeds, Andrew M; Hampel, Stefanie; Coutinho-Budd, Jaeda C; Farley, Jonathan E; Wong, Jack; Karadeniz, Yonca B; Osterloh, Jeannette M; Sheehan, Amy E; Freeman, Marc R

    2017-07-05

    Axon degeneration is a hallmark of neurodegenerative disease and neural injury. Axotomy activates an intrinsic pro-degenerative axon death signaling cascade involving loss of the NAD(+) biosynthetic enzyme Nmnat/Nmnat2 in axons, activation of dSarm/Sarm1, and subsequent Sarm-dependent depletion of NAD(+). Here we identify Axundead (Axed) as a mediator of axon death. axed mutants suppress axon death in several types of axons for the lifespan of the fly and block the pro-degenerative effects of activated dSarm in vivo. Neurodegeneration induced by loss of the sole fly Nmnat ortholog is also fully blocked by axed, but not dsarm, mutants. Thus, pro-degenerative pathways activated by dSarm signaling or Nmnat elimination ultimately converge on Axed. Remarkably, severed axons morphologically preserved by axon death pathway mutations remain integrated in circuits and able to elicit complex behaviors after stimulation, indicating that blockade of axon death signaling results in long-term functional preservation of axons. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Penicillamin-induced neuropathy in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Pedersen, P B; Hogenhaven, H

    1990-01-01

    A case of penicillamin-induced severe polyradiculopathy in rheumatoid arthritis is presented. The neuropathy was of demyelinating type, purely motor, proximal and clinically fully reversible when the drug ceased. In case of a progressive neuropathy, during penicillamin treatment, this adverse...

  3. Disulfiram-induced neuropathy: a case report.

    Science.gov (United States)

    Mohapatra, Satyakam; Sahoo, Manas Ranjan; Rath, Neelmadhav

    2015-01-01

    Disulfiram is widely used for aversive treatment of alcoholism. Neuropathy is one of the most severe side effects of disulfiram therapy. We report the case of a young man who developed a neuropathy following disulfiram administration, with a virtually complete recovery within 2 months.

  4. Demyelinating polyneuropathy in Leber hereditary optic neuropathy.

    NARCIS (Netherlands)

    Gilhuis, H.J.; Schelhaas, H.J.; Cruysberg, J.R.M.; Zwarts, M.J.

    2006-01-01

    We report a patient with Leber hereditary optic neuropathy (G11778A mtDNA) and a severe demyelinating neuropathy, for which no other cause except his mitochondrial disorder could be found. The involvement of the peripheral nervous system of patients with LHON, in particular with a 11778 mtDNA, is di

  5. Tart Cherry Juice as a Treatment for Peripheral Neuropathy

    Science.gov (United States)

    Carson, Cindy Alberts

    2015-01-01

    Introduction Tart cherries have a long history as a treatment for gout and joint pain. While the exact mechanism of action is unknown, it is believed that acanthocyanin pigments and related bioflavonoids found in tart cherries and other red fruits scavenge free radicals, modulate cytokines, reduce DNA degradation, decrease capillary permeability, inhibit cyclooxygenase, and strengthen biological membranes. Many of these biochemical reactions would be expected to reduce inflammation, pain, and edema. Significance of Study Peripheral polyneuropathies are common and are believed to affect up to 9% of the US population older than 50 y. These neuropathies may develop from direct compression of peripheral nerves, toxic or metabolic injury to nerve tissue, autoimmune attack, or nutritional deficiency. No cause is identified in approximately 30% of patients. The pathophysiology of polyneuropathies is complex and not fully understood, but 3 common patterns of damage occur: (1) distal axonopathy, where the cell bodies remain intact, but axons degenerate from distal to proximal, usually as the result of toxic or metabolic injury; (2) demyelination neuropathy, where damage to the myelin sheath from autoimmune, infectious, or other causes disrupts electrical signaling; and (3) ganglionopathies, where damage occurs at the cell body or neuron, a relatively rare occurrence. While weakness and loss of sensation are common in many peripheral polyneuropathies, “gain of function” symptoms, such as paresthesias and allodynia, are the most distressing and are very difficult to treat. It is believed that these symptoms are caused by alterations in ion channels, alterations in neurotransmitters and their receptors, and altered gene expression. Common conventional treatments include antiepileptics, antidepressants, NSAIDs, and narcotics. These medications alter ion channels and neurotransmitters, decrease the sensitivity of nociceptive receptors, and desensitize C fibers. Most patients

  6. Respiratory muscle weakness in peripheral neuropathies.

    Science.gov (United States)

    Burakgazi, Ahmet Z; Höke, Ahmet

    2010-12-01

    Common peripheral neuropathies do not usually cause diaphragmatic weakness and subsequent respiratory compromise. However, respiratory involvement is relatively common in Guillain-Barré syndrome (GBS). Experience in GBS has led to a standardized approach to manage respiratory problems in peripheral neuropathies. Diaphragmatic weakness is not common in chronic inflammatory demyelinating polyneuropathy and extremely rare in multifocal motor neuropathy. The linkage has been described between certain subtypes of Charcot-Marie-Tooth (CMT) disease such as CMT2C and CMT4B1 and diaphragmatic weakness. A correlation usually has not been found between electrophysiologic findings and clinical respiratory signs or spirometric abnormalities in peripheral neuropathies except in amplitudes of evoked phrenic nerve responses. Careful and frequent assessment of respiratory function by a qualified team of healthcare professionals and physicians is essential. Criteria established for mechanical ventilation in GBS cases may be applied to other peripheral neuropathies with respiratory compromise as necessary.

  7. The diabetic neuropathies: practical and rational therapy.

    Science.gov (United States)

    Singleton, J Robinson; Smith, A Gordon

    2012-07-01

    Diabetes is associated with a variety of chronic and acute neuropathies. In this article, the authors summarize the clinical features of the most common diabetic neuropathies, focusing on those for which therapy is available or under active investigation. Distal symmetric polyneuropathy (DSP) is the most common form. Potential treatments for DSP are discussed in four broad themes: (1) medication and lifestyle therapy to improve hyperglycemia, insulin resistance, and attendant features of metabolic syndrome, including obesity and dyslipidemia; (2) pharmacologic therapy to alter neuropathy natural history aimed at rational targets from known pathophysiology; (3) symptomatic relief of neuropathic pain; and (4) treatment to prevent complications of neuropathy, including stasis ulcers and falls. The approach to the most common acute diabetic neuropathies is also reviewed. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Optimal myelin elongation relies on YAP activation by axonal growth and inhibition by Crb3/Hippo pathway

    Science.gov (United States)

    Fernando, Ruani N.; Cotter, Laurent; Perrin-Tricaud, Claire; Berthelot, Jade; Bartolami, Sylvain; Pereira, Jorge A.; Gonzalez, Sergio; Suter, Ueli; Tricaud, Nicolas

    2016-01-01

    Fast nerve conduction relies on successive myelin segments that electrically isolate axons. Segment geometry—diameter and length—is critical for the optimization of nerve conduction and the molecular mechanisms allowing this optimized geometry are partially known. We show here that peripheral myelin elongation is dynamically regulated by stimulation of YAP (Yes-associated protein) transcription cofactor activity during axonal elongation and limited by inhibition of YAP activity via the Hippo pathway. YAP promotes myelin and non-myelin genes transcription while the polarity protein Crb3, localized at the tips of the myelin sheath, activates the Hippo pathway to temper YAP activity, therefore allowing for optimal myelin growth. Dystrophic Dy2j/2j mice mimicking human peripheral neuropathy with reduced internodal lengths have decreased nuclear YAP which, when corrected, leads to longer internodes. These data show a novel mechanism controlling myelin growth and nerve conduction, and provide a molecular ground for disease with short myelin segments. PMID:27435623

  9. Pathogenesis of Painful Diabetic Neuropathy

    OpenAIRE

    Amir Aslam; Jaipaul Singh; Satyan Rajbhandari

    2014-01-01

    The prevalence of diabetes is rising globally and, as a result, its associated complications are also rising. Painful diabetic neuropathy (PDN) is a well-known complication of diabetes and the most common cause of all neuropathic pain. About one-third of all diabetes patients suffer from PDN. It has a huge effect on a person's daily life, both physically and mentally. Despite huge advances in diabetes and neurology, the exact mechanism of pain causation in PDN is still not clear. The origin o...

  10. [Treatment of multifocal motor neuropathies].

    Science.gov (United States)

    Azulay, J P; Pouget, J; Rihet, P; Serratrice, G

    1996-05-01

    Multifocal motor neuropathy is characterized by a progressive asymetrical weakness, predominantly affecting the upper limbs with persistent conduction blocks on motor but not sensory nerves. Treatment woth prednisone and plasma exchanges have failed to demonstrate any positive effects. Some improvements have been reported with cyclophosphamide. Mainly immunoglobulin therapy has been evaluated with a beneficial response in almost 70% of the cases. These benefits obtained over periods of less than six months have recently been confirmed by a long-term evaluation of 18 patients treated by repeated infusions.

  11. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  12. MR imaging of trigeminal neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Yeon; Yoon, Pyeong Ho; Chung, Jin Il; Lee, Seung Ik; Kim, Dong Ik [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    2001-03-01

    The trigeminal nerve is the largest of the cranial nerves and has both sensory and motor functions. It can be divided into proximal (brainstem, preganglionic, gasserian ganglion, and cavernous sinus) and distal (extracranial opthalmic, maxillary, and mandibular) segments. Patients with trigeminal neuropathy present with a wide variety of symptoms, and lesions producing those symptoms may occur anywhere along the protracted course of the trigeminal nerve, from its distal facial branches to its nuclear columns in the brainstem. The purpose of this article is to illustrate the normal anatomy of the trigeminal nerve and associated various pathologic conditions. These are arranged anatomically according to their site of interaction with it.

  13. Autosomal recessive hereditary auditory neuropathy

    Institute of Scientific and Technical Information of China (English)

    王秋菊; 顾瑞; 曹菊阳

    2003-01-01

    Objectives: Auditory neuropathy (AN) is a sensorineural hearing disorder characterized by absent or abnormal auditory brainstem responses (ABRs) and normal cochlear outer hair cell function as measured by otoacoustic emissions (OAEs). Many risk factors are thought to be involved in its etiology and pathophysiology. Three Chinese pedigrees with familial AN are presented herein to demonstrate involvement of genetic factors in AN etiology. Methods: Probands of the above - mentioned pedigrees, who had been diagnosed with AN, were evaluated and followed up in the Department of Otolaryngology Head and Neck Surgery, China PLA General Hospital. Their family members were studied and the pedigree diagrams were established. History of illness, physical examination,pure tone audiometry, acoustic reflex, ABRs and transient evoked and distortion- product otoacoustic emissions (TEOAEs and DPOAEs) were obtained from members of these families. DPOAE changes under the influence of contralateral sound stimuli were observed by presenting a set of continuous white noise to the non - recording ear to exam the function of auditory efferent system. Some subjects received vestibular caloric test, computed tomography (CT)scan of the temporal bone and electrocardiography (ECG) to exclude other possible neuropathy disorders. Results: In most affected subjects, hearing loss of various degrees and speech discrimination difficulties started at 10 to16 years of age. Their audiological evaluation showed absence of acoustic reflex and ABRs. As expected in AN, these subjects exhibited near normal cochlear outer hair cell function as shown in TEOAE & DPOAE recordings. Pure- tone audiometry revealed hearing loss ranging from mild to severe in these patients. Autosomal recessive inheritance patterns were observed in the three families. In Pedigree Ⅰ and Ⅱ, two affected brothers were found respectively, while in pedigree Ⅲ, 2 sisters were affected. All the patients were otherwise normal without

  14. Muscular atrophy in diabetic neuropathy

    DEFF Research Database (Denmark)

    Andersen, H; Gadeberg, P C; Brock, B

    1997-01-01

    Diabetic patients with polyneuropathy develop motor dysfunction. To establish whether motor dysfunction is associated with muscular atrophy the ankle dorsal and plantar flexors of the non-dominant leg were evaluated with magnetic resonance imaging in 8 patients with symptomatic neuropathy, in 8 non...... confirmed that the atrophy predominated distally. We conclude that muscular atrophy underlies motor weakness at the ankle in diabetic patients with polyneuropathy and that the atrophy is most pronounced in distal muscles of the lower leg indicating that a length dependent neuropathic process explains...

  15. Axon initial segment Kv1 channels control axonal action potential waveform and synaptic efficacy.

    Science.gov (United States)

    Kole, Maarten H P; Letzkus, Johannes J; Stuart, Greg J

    2007-08-16

    Action potentials are binary signals that transmit information via their rate and temporal pattern. In this context, the axon is thought of as a transmission line, devoid of a role in neuronal computation. Here, we show a highly localized role of axonal Kv1 potassium channels in shaping the action potential waveform in the axon initial segment (AIS) of layer 5 pyramidal neurons independent of the soma. Cell-attached recordings revealed a 10-fold increase in Kv1 channel density over the first 50 microm of the AIS. Inactivation of AIS and proximal axonal Kv1 channels, as occurs during slow subthreshold somatodendritic depolarizations, led to a distance-dependent broadening of axonal action potentials, as well as an increase in synaptic strength at proximal axonal terminals. Thus, Kv1 channels are strategically positioned to integrate slow subthreshold signals, providing control of the presynaptic action potential waveform and synaptic coupling in local cortical circuits.

  16. The diagnostic and prognostic value of neurofilament heavy chain levels in immune-mediated optic neuropathies.

    Science.gov (United States)

    Petzold, Axel; Plant, Gordon T

    2012-01-01

    Background. Loss of visual function differs between immune-mediated optic neuropathies and is related to axonal loss in the optic nerve. This study investigated the diagnostic and prognostic value of a biomarker for neurodegeneration, the neurofilament heavy chain (NfH) in three immune-mediated optic neuropathies. Methods. A prospective, longitudinal study including patients with optic neuritis due to multiple sclerosis (MSON, n = 20), chronic relapsing inflammatory optic neuritis (CRION, n = 19), neuromyelitis optica (NMO, n = 9), and healthy controls (n = 28). Serum NfH-SMI35 levels were quantified by ELISA. Findings. Serum NfH-SMI35 levels were highest in patients with NMO (mean 0.79 ± 1.51 ng/mL) compared to patients with CRION (0.13 ± 0.16 ng/mL, P = 0.007), MSON (0.09 ± 0.09, P = 0.008), and healthy controls (0.01 ± 0.02 ng/mL, P = 0.001). High serum NfH-SMI35 levels were related to poor visual outcome. Conclusions. Blood NfH-SMI35 levels are of moderate diagnostic and more important prognostic value in immune-mediated optic neuropathies. We speculate that longitudinal blood NfH levels may help to identify particular disabling events in relapsing conditions.

  17. The Diagnostic and Prognostic Value of Neurofilament Heavy Chain Levels in Immune-Mediated Optic Neuropathies

    Directory of Open Access Journals (Sweden)

    Axel Petzold

    2012-01-01

    Full Text Available Background. Loss of visual function differs between immune-mediated optic neuropathies and is related to axonal loss in the optic nerve. This study investigated the diagnostic and prognostic value of a biomarker for neurodegeneration, the neurofilament heavy chain (NfH in three immune-mediated optic neuropathies. Methods. A prospective, longitudinal study including patients with optic neuritis due to multiple sclerosis (MSON, n=20, chronic relapsing inflammatory optic neuritis (CRION, n=19, neuromyelitis optica (NMO, n=9, and healthy controls (n=28. Serum NfH-SMI35 levels were quantified by ELISA. Findings. Serum NfH-SMI35 levels were highest in patients with NMO (mean 0.79±1.51 ng/mL compared to patients with CRION (0.13±0.16 ng/mL, P=0.007, MSON (0.09±0.09, P=0.008, and healthy controls (0.01±0.02 ng/mL, P=0.001. High serum NfH-SMI35 levels were related to poor visual outcome. Conclusions. Blood NfH-SMI35 levels are of moderate diagnostic and more important prognostic value in immune-mediated optic neuropathies. We speculate that longitudinal blood NfH levels may help to identify particular disabling events in relapsing conditions.

  18. [Hereditary optic neuropathies: clinical and molecular genetic characteristics].

    Science.gov (United States)

    Khanakova, N A; Sheremet, N L; Loginova, A N; Chukhrova, A L; Poliakov, A V

    2013-01-01

    The article presents a review of literature on hereditary optic neuropathies: Leber mitochondrial hereditary optic neuropathy, autosomal dominant and autosomal recessive optic neuropathies, X-linked optic atrophy. Clinical and molecular genetic characteristics are covered. Isolated optic neuropathies, as well as hereditary optic disorders, being a part of a complex syndromic disease are described.

  19. The Relationship between Dyslipidemia and Acute Axonal Function in Type 2 Diabetes Mellitus In Vivo

    Science.gov (United States)

    Kwai, Natalie C. G.; Nigole, William; Poynten, Ann M.; Brown, Christopher; Krishnan, Arun V.

    2016-01-01

    Objectives Diabetic peripheral neuropathy (DPN) is a common and debilitating complication of diabetes mellitus. Treatment largely consists of symptom alleviation and there is a need to identify therapeutic targets for prevention and treatment of DPN. The objective of this study was to utilise novel neurophysiological techniques to investigate axonal function in patients with type 2 diabetes and to prospectively determine their relationship to serum lipids in type 2 diabetic patients. Methods Seventy-one patients with type 2 diabetes were consecutively recruited and tested. All patients underwent thorough clinical neurological assessments including nerve conduction studies, and median motor axonal excitability studies. Studies were also undertaken in age matched normal control subjects(n = 42). Biochemical studies, including serum lipid levels were obtained in all patients. Patient excitability data was compared to control data and linear regression analysis was performed to determine the relationship between serum triglycerides and low density lipoproteins and excitability parameters typically abnormal in type 2 diabetic patients. Results Patient mean age was 64.2±2.3 years, mean glycosylated haemoglobin (HbA1c%) was 7.8±0.3%, mean triglyceride concentration was 1.6±0.1 mmol/L and mean cholesterol concentration was 4.1±0.2mmol/L. Compared to age matched controls, median motor axonal excitability studies indicated axonal dysfunction in type 2 diabetic patients as a whole (T2DM) and in a subgroup of the patients without DPN (T2DM-NN). These included reduced percentage threshold change during threshold electrotonus at 10–20ms depolarising currents (TEd10–20ms)(controls 68.4±0.8, T2DM63.9±0.8, T2DM-NN64.8±1.6%,P<0.05) and superexcitability during the recovery cycle (controls-22.5±0.9, T2DM-17.5±0.8, T2DM-NN-17.3±1.6%,P<0.05). Linear regression analysis revealed no associations between changes in axonal function and either serum triglyceride or low density

  20. The clinical approach to small fibre neuropathy and painful channelopathy.

    Science.gov (United States)

    Themistocleous, Andreas C; Ramirez, Juan D; Serra, Jordi; Bennett, David L H

    2014-12-01

    Small fibre neuropathy (SFN) is characterised by structural injury selectively affecting small diameter sensory and/or autonomic axons. The clinical presentation is dominated by pain. SFN complicates a number of common diseases such as diabetes mellitus and is likely to be increasingly encountered. The diagnosis of SFN is demanding as clinical features can be vague and nerve conduction studies normal. New diagnostic techniques, in particular measurement of intraepidermal nerve fibre density, have significantly improved the diagnostic efficiency of SFN. Management is focused on the treatment of the underlying cause and analgesia, as there is no neuroprotective therapy. A recent and significant advance is the finding that a proportion of cases labelled as idiopathic SFN are in fact associated with gain of function mutations of the voltage-gated sodium channels Nav1.7 and Nav1.8 (encoded by the genes SCN9A and SCN10A, respectively). There is a further group of heritable painful conditions in which gain of function mutations in ion channels alter excitability of sensory neurones but do not cause frank axon degeneration; these include mutations in Nav1.7 (causing erythromelalgia and paroxysmal extreme pain disorder) and TRPA1 (resulting in familial episodic pain disorder). These conditions are exceptionally rare but have provided great insight into the nociceptive system as well as yielding potential analgesic drug targets. In patients with no pre-existing risk factor, the investigation of an underlying cause of SFN should be systematic and appropriate for the patient population. In this review, we focus on how to incorporate recent developments in the diagnosis and pathophysiology of SFN into clinical practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Axon tension regulates fasciculation/defasciculation through the control of axon shaft zippering

    Science.gov (United States)

    Šmít, Daniel; Fouquet, Coralie; Pincet, Frédéric; Zapotocky, Martin; Trembleau, Alain

    2017-01-01

    While axon fasciculation plays a key role in the development of neural networks, very little is known about its dynamics and the underlying biophysical mechanisms. In a model system composed of neurons grown ex vivo from explants of embryonic mouse olfactory epithelia, we observed that axons dynamically interact with each other through their shafts, leading to zippering and unzippering behavior that regulates their fasciculation. Taking advantage of this new preparation suitable for studying such interactions, we carried out a detailed biophysical analysis of zippering, occurring either spontaneously or induced by micromanipulations and pharmacological treatments. We show that zippering arises from the competition of axon-axon adhesion and mechanical tension in the axons, and provide the first quantification of the force of axon-axon adhesion. Furthermore, we introduce a biophysical model of the zippering dynamics, and we quantitatively relate the individual zipper properties to global characteristics of the developing axon network. Our study uncovers a new role of mechanical tension in neural development: the regulation of axon fasciculation. DOI: http://dx.doi.org/10.7554/eLife.19907.001 PMID:28422009

  2. Autonomic neuropathy in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Alberto eVerrotti

    2014-12-01

    Full Text Available Diabetic autonomic neuropathy (DAN is a serious and common complication of diabetes, often overlooked and misdiagnosed. It is a systemic-wide disorder that may be asymptomatic in the early stages. The most studied and clinically important form of DAN is cardiovascular autonomic neuropathy (CAN defined as the impairment of autonomic control of the cardiovascular system in patients with diabetes after exclusion of other causes. The reported prevalence of DAN varies widely depending on inconsistent definition, different diagnostic method, different patient cohorts studied. The pathogenesis is still unclear and probably multifactorial. Once DAN becomes clinically evident, no form of therapy has been identified which can effectively stop or reverse it. Prevention strategies are based on strict glycemic control with intensive insulin treatment, multifactorial intervention and lifestyle modification including control of hypertension, dyslipidemia, stop smoking, weight loss and adequate physical exercise. The present review summarizes the latest knowledge regarding clinical presentation, epidemiology, pathogenesis and management of DAN, with some mention to childhood and adolescent population.

  3. Calciphylaxis and bilateral optic neuropathy.

    Science.gov (United States)

    Huerva, V; Sánchez, M C; Ascaso, F J; Craver, L; Fernández, E

    2011-11-01

    A 51-year-old woman on hemodialysis for chronic renal failure complained of visual loss in her right eye. Right optic disc edema was observed on fundus examination. An arteritic optic neuropathy was suspected. However, a first biopsy did not reveal any inflammatory cells. Two months later, the patient experienced sudden visual loss in her left eye and presented with necrotic cutaneous lesions at the distal phalanges of several fingers of the right hand. Necrotic lesions also appeared on the inner aspect of the thighs. Biopsy of the cutaneous lesions revealed calcification in the wall of a small artery. A new biopsy of the temporal artery showed large calcium deposits in the artery's tunica media. The diagnosis of optic neuropathy secondary to calciphylaxis was made. A temporal artery biopsy should be repeated if the first one is inconclusive. An early diagnosis leading to appropriate treatment may help to prevent an irreversible loss of vision in these patients. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  4. Vincristine-induced cranial neuropathy.

    Science.gov (United States)

    Talebian, Ahmad; Goudarzi, Razieh Moazam; Mohammadzadeh, Mahdi; Mirzadeh, Azadeh Sadat

    2014-01-01

    Vincristine (VCR) is a vinca alkaloid that is used for treatment of many malignancies. The vinca alkaloids are neurotoxic, usually causing a peripheral neuropathy, but cranial neuropathies are rare as side effects. Described here is the case of a 2.5-year-old boy, a known case of Wilms' tumor, treated by vincristine (0.067 mg/kg/day) and dactinomycin (0.045 mg/kg/day) after surgery. Three weeks after treatment, he presented with bilateral ptosis. Neurological examination revealed bilateral ptosis with normal pupillary reflex and eye movement. He received 3.015 mg cumulative dose of vincristine before development of ptosis. Treatment with pyridoxine (150 mg/m2 p.o. BID) and pyridostigmine (3 mg/kg p.o. BID) was started as neuroprotective agents, and after 7 days the problem disappeared. The treatment continued for 6 weeks and there were no signs of ptosis or a recurrence in follow up 2 months later.

  5. Recessively transmitted predominantly motor neuropathies.

    Science.gov (United States)

    Parman, Yeşim; Battaloğlu, Esra

    2013-01-01

    Recessively transmitted predominantly motor neuropathies are rare and show a severe phenotype. They are frequently observed in populations with a high rate of consanguineous marriages. At least 15 genes and six loci have been found to be associated with autosomal recessive CMT (AR-CMT) and X-linked CMT (AR-CMTX) and also distal hereditary motor neuronopathy (AR-dHMN). These disorders are genetically heterogeneous but the clinical phenotype is relatively homogeneous. Distal muscle weakness and atrophy predominating in the lower extremities, diminished or absent deep tendon reflexes, distal sensory loss, and pes cavus are the main clinical features of this disorder with occasional cranial nerve involvement. Although genetic diagnosis of some of subtypes of AR-CMT are now available, rapid advances in the molecular genetics and cell biology show a great complexity. Animal models for the most common subtypes of human AR-CMT disease provide clues for understanding the pathogenesis of CMT and also help to reveal possible treatment strategies of inherited neuropathies. This chapter highlights the clinical features and the recent genetic and biological findings in these disorders based on the current classification.

  6. Genetic dissection of myelinated axons in zebrafish

    OpenAIRE

    2009-01-01

    In the vertebrate nervous system, the myelin sheath allows for rapid and efficient conduction of action potentials along axons. Despite the essential function of myelin, many questions remain unanswered about the mechanisms that govern the development of myelinated axons. The fundamental properties of myelin are widely shared among vertebrates, and the zebrafish has emerged as a powerful system to study myelination in vivo. This review will highlight recent advances from genetic screens in ze...

  7. Human Genetic Disorders of Axon Guidance

    OpenAIRE

    Engle, Elizabeth C

    2010-01-01

    This article reviews symptoms and signs of aberrant axon connectivity in humans, and summarizes major human genetic disorders that result, or have been proposed to result, from defective axon guidance. These include corpus callosum agenesis, L1 syndrome, Joubert syndrome and related disorders, horizontal gaze palsy with progressive scoliosis, Kallmann syndrome, albinism, congenital fibrosis of the extraocular muscles type 1, Duane retraction syndrome, and pontine tegmental cap dysplasia. Gene...

  8. Vincristine-Induced Cranial Neuropathy

    Directory of Open Access Journals (Sweden)

    Ahmad TALEBIAN*

    2014-01-01

    Full Text Available How to Cite This Article: Talebian A, Goudarzi RM, Mohammadzadeh M , Mirzadeh AS. Vincristine-Induced Cranial Neuropathy. Iran J Child Neurol. 2014 Winter; 8(1:66-68. AbstractVincristine (VCR is a vinca alkaloid that is used for treatment of many malignancies.The vinca alkaloids are neurotoxic, usually causing a peripheral neuropathy, but cranial neuropathies are rare as side effects. Described here is the case of a 2.5-year-old boy, a known case of Wilms’ tumor, treated by vincristine (0/067 mg/kg/day and dactinomycin (0/045 mg/kg/day after surgery. Three weeks after treatment, he presented with bilateral ptosis.Neurological examination revealed bilateral ptosis with normal pupillary reflex and eye movement. He received 3.015 mg cumulative dose of vincristine before development of ptosis.Treatment with pyridoxine (150 mg/m2 p.o. BID and pyridostigmine (3 mg/kg p.o. BID started as neuroprotective agents, and after 7 days the problem disappeared.The treatment continued for 6 weeks and there were no signs of ptosis or a recurrence in follow up 2 months later. References:Toopchizade V, Hosseini M, et al. Electrophysiological signs of neuropathy caused by vincristine. Medical Journal of Tabriz University of Medical Sciences. 2010 Autumn;31(3; 19-25.Gursel E.S. Vincristine-Induced Unilateral Ptosis in a Child. Pediatr Neurol 2009; 41:461-463.Ngamphaiboon N, Sweeney R, Wetzler M, Wang ES. Pyridoxine treatment of vincristine-induced cranial polyneuropathy in an adult patient with acute lymphocytic leukemia: Case report and review of the literature. Leuk Res. 2010 Aug;34(8:e194-6.Lash SC, Williams CP, Marsh CS, Crithchley C, Hodgkins PR, Mackie EJ. Acute Sixth-Nerve Palsy After Vincristine Therapy. Journal of AAPOS 2004 Feb;8(1: 67-8.Bay A, Yilmaz C, Yilmaz N, Oner AF. Vincristine induced cranial polyneuropathy. Indian J Pediatr. 2006 Jun;73(6:531-3.Tuxen M K, Hansen SW. Complication of treatment, Neurotoxicity secondary to antineoplastic

  9. Crossing axons in the third nerve nucleus.

    Science.gov (United States)

    Bienfang, D C

    1975-12-01

    The research presented in this paper studied the pathway taken by the crossed fibers of the third nerve nucleus in an animal whose nucleus has been well mapped and found to correlate well with higher mammals and man. Autoradiography using tritiated amino acid labeled the cell bodies an axons of the left side of the oculomotor nucleus of the cat. Axons so labeled could be seen emerging from the ventral portion of the left nucleus through the median longitudinal fasciculus (mlf) to join the left oculomotor nerve. Labeled axons were also seen to emerge from the medial border of the caudal left nucleus, cross the midline, and pass through the right nucleus and the right mlf to join the right oculomotor nerve. These latter axons must be the crossed axons of the superior rectus and levator palpebrae subnuclei. Since the path of these crossed axons is through the caudal portion of the nucleus of the opposite side, the destruction of one lateral half of the oculomotor nucleus would result in a bilateral palsy of the crossed subnuclei. Bilateral palsy of the superior rectus and bilateral assymetrical palsy of the levator palpebrae muscles would result.

  10. Delayed feedback model of axonal length sensing.

    Science.gov (United States)

    Karamched, Bhargav R; Bressloff, Paul C

    2015-05-05

    A fundamental question in cell biology is how the sizes of cells and organelles are regulated at various stages of development. Size homeostasis is particularly challenging for neurons, whose axons can extend from hundreds of microns to meters (in humans). Recently, a molecular-motor-based mechanism for axonal length sensing has been proposed, in which axonal length is encoded by the frequency of an oscillating retrograde signal. In this article, we develop a mathematical model of this length-sensing mechanism in which advection-diffusion equations for bidirectional motor transport are coupled to a chemical signaling network. We show that chemical oscillations emerge due to delayed negative feedback via a Hopf bifurcation, resulting in a frequency that is a monotonically decreasing function of axonal length. Knockdown of either kinesin or dynein causes an increase in the oscillation frequency, suggesting that the length-sensing mechanism would produce longer axons, which is consistent with experimental findings. One major prediction of the model is that fluctuations in the transport of molecular motors lead to a reduction in the reliability of the frequency-encoding mechanism for long axons. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. Chronic dysimmune neuropathies: Beyond chronic demyelinating polyradiculoneuropathy

    Directory of Open Access Journals (Sweden)

    Khadilkar Satish

    2011-01-01

    Full Text Available The spectrum of chronic dysimmune neuropathies has widened well beyond chronic demyelinating polyradiculoneuropathy (CIDP. Pure motor (multifocal motor neuropathy, sensorimotor with asymmetrical involvement (multifocal acquired demylinating sensory and motor neuropathy, exclusively distal sensory (distal acquired demyelinating sensory neuropathy and very proximal sensory (chronic immune sensory polyradiculopathy constitute the variants of CIDP. Correct diagnosis of these entities is of importance in terms of initiation of appropriate therapy as well as prognostication of these patients. The rates of detection of immune-mediated neuropathies with monoclonal cell proliferation (monoclonal gammopathy of unknown significance, multiple myeloma, etc. have been facilitated as better diagnostic tools such as serum immunofixation electrophoresis are being used more often. Immune neuropathies associated with malignancies and systemic vasculitic disorders are being defined further and treated early with better understanding of the disease processes. As this field of dysimmune neuropathies will evolve in the future, some of the curious aspects of the clinical presentations and response patterns to different immunosuppressants or immunomodulators will be further elucidated. This review also discusses representative case studies.

  12. Drugs for the treatment of peripheral neuropathies.

    Science.gov (United States)

    Marmiroli, Paola; Cavaletti, Guido

    2016-01-01

    Peripheral neuropathies are frequent in association with systemic diseases as well as isolated disorders. Recent advances in the therapy of specific neuropathies led to the approval of new drugs/treatments. This review selected those peripheral neuropathies where the most recent approvals were provided and revised the potential future developments in diabetic and toxic-induced neuropathies, although they do not have a currently available causal therapy in view of their epidemiological and social relevance. Data have been extracted from the most important published trials and from clinical experience. In addition, data from the Food and Drug Administration and European Medicine Agency indications on the treatment of the selected peripheral neuropathies and from recently updated international guidelines have also been included. The website of the U.S. National Institutes of Health www.clinicaltrials.gov registry has been used as the reference database for phase III clinical trials not yet published or ongoing. This review gives a general overview of the most recent advances in the treatment of amyloid, inflammatory, and paraproteinemic peripheral neuropathies. Moreover, it briefly describes the unmet medical need in disabling and frequent conditions, such as diabetic and chemotherapy-induced neuropathy, highlighting the most promising therapeutic approaches to their treatment.

  13. SARM1 activation triggers axon degeneration locally via NAD+ destruction

    OpenAIRE

    Gerdts, Josiah; Brace, E. J.; Sasaki, Yo; DiAntonio, Aaron; Milbrandt, Jeffrey

    2015-01-01

    Axon degeneration is an intrinsic self-destruction program that underlies axon loss during injury and disease. Sterile alpha and TIR motif containing 1 (SARM1) protein is an essential mediator of axon degeneration. We report that SARM1 initiates a local destruction program involving rapid breakdown of NAD+ after injury. We used an engineered protease-sensitized SARM1 to demonstrate that SARM1 activity is required after axon injury to induce axon degeneration. Dimerization of the Toll-Interleu...

  14. [Sequential nerve conduction studies in a patient with ulnar neuropathy at the elbow treated by night athletic supporter].

    Science.gov (United States)

    Hasegawa, O; Matsumoto, S; Iino, M; Kirigaya, N; Wada, N; Mimura, E

    2000-05-01

    Ulnar nerve can be stretched with the elbow flexed position. To avoid elbow flexed position in patients with ulnar neuropathy at the elbow we used an athletic elbow supporter. We herein demonstrate a 31-year-old man with right ulnar neuropathy at the elbow whose neuropathy was resolved by using this supporter only at night. He had complained of weakness and paraesthesia in the ulnar side of his right hand. Nerve conduction studies of right ulnar nerve revealed decrease in the amplitude of compound nerve action potentials and a severe motor nerve conduction block with apparent conduction delay around the ulnar groove. A diagnosis of ulnar neuropathy at the elbow was done and we recommended him to wear an athletic elbow supporter at night. Paraesthesia of his right hand improved in a few days after starting this therapy. Three months later paraesthesia was resolved. One year later grip power of his right hand increased to 35 kg from 20 kg, and the conduction block at the elbow completely disappeared. Compound nerve action potentials, recorded at the segment of wrist to above elbow and wrist to finger, were improved equally. These observations suggest that the conduction block at the elbow entrapment site and the distal axonal degeneration gradually recovered together.

  15. In vivo gene therapy for pyridoxine-induced neuropathy by herpes simplex virus-mediated gene transfer of neurotrophin-3.

    Science.gov (United States)

    Chattopadhyay, Munmun; Wolfe, Darren; Huang, Shaohua; Goss, James; Glorioso, Joseph C; Mata, Marina; Fink, David J

    2002-01-01

    Neurotrophic factors have been demonstrated to prevent the development of peripheral neuropathy in animal models, but the therapeutic use of these factors in human disease has been limited by the short serum half-life and dose-limiting side effects of these potent peptides. We used peripheral subcutaneous inoculation with a replication-incompetent, genomic herpes simplex virus-based vector containing the coding sequence for neurotrophin-3 to transduce sensory neurons of the rat dorsal root ganglion in vivo, and found that expression of neurotrophin-3 from the vector protected peripheral sensory axons from neuropathy induced by intoxication with pyridoxine assessed by electrophysiological (foot sensory response amplitude, and conduction velocity, and H-wave), histological (nerve morphology and morphometry), and behavioral measures of proprioceptive function. In vivo gene transfer using herpes simplex virus vectors provides a unique option for treatment of diseases of the sensory peripheral nervous system.

  16. The Neurophysiologic Frequency of Hereditary Neuropathy with Liability to Pressure Palsy in Entrapment Neuropathies

    Directory of Open Access Journals (Sweden)

    F Gökçem Yıldız

    2016-12-01

    Full Text Available Objective: Hereditary neuropathy with liability to pressure palsy (HNPP needs to be differentiated from entrapment neuropathies due to differences in the treatment management. Materials and Methods: Among 5075 patients with entrapment neuropathy, we retrospectively evaluated the neurophysiologic results of 20 patients with three or more entrapments. Results: Ten patients were diagnosed as having HNPP according to their genetic or nerve biopsy results; eight (80% had bilateral Carpal tunnel syndrome, nine (90% had bilateral ulnar entrapment neuropathy, eight (80% had bilateral median and ulnar entrapment together; and three (30% had one-sided peroneal neuropathy. Conclusion: Our data suggest that analyzing the neurophysiologic studies and keeping HNPP in mind are essential to characterize underdiagnosed patients with HNPP referred for entrapment neuropathy.

  17. Central nervous system involvement in diabetic neuropathy.

    Science.gov (United States)

    Selvarajah, Dinesh; Wilkinson, Iain D; Davies, Jennifer; Gandhi, Rajiv; Tesfaye, Solomon

    2011-08-01

    Diabetic neuropathy is a chronic and often disabling condition that affects a significant number of individuals with diabetes. Long considered a disease of the peripheral nervous system, there is now increasing evidence of central nervous system involvement. Recent advances in neuroimaging methods detailed in this review have led to a better understanding and refinement of how diabetic neuropathy affects the central nervous system. Recognition that diabetic neuropathy is, in part, a disease that affects the whole nervous system is resulting in a critical rethinking of this disorder, opening a new direction for further research.

  18. Compressive neuropathy in the upper limb

    Directory of Open Access Journals (Sweden)

    Mukund R Thatte

    2011-01-01

    Full Text Available Entrampment neuropathy or compression neuropathy is a fairly common problem in the upper limb. Carpal tunnel syndrome is the commonest, followed by Cubital tunnel compression or Ulnar Neuropathy at Elbow. There are rarer entities like supinator syndrome and pronator syndrome affecting the Radial and Median nerves respectively. This article seeks to review comprehensively the pathophysiology, Anatomy and treatment of these conditions in a way that is intended for the practicing Hand Surgeon as well as postgraduates in training. It is generally a rewarding exercise to treat these conditions because they generally do well after corrective surgery. Diagnostic guidelines, treatment protocols and surgical technique has been discussed.

  19. Serum Antibodies to Glycans in Peripheral Neuropathies.

    Science.gov (United States)

    Sonnino, Sandro; Chiricozzi, Elena; Ciampa, Maria Grazia; Mauri, Laura; Prinetti, Alessandro; Toffano, Gino; Aureli, Massimo

    2017-03-01

    In peripheral neuropathies, such as sensorimotor neuropathies, motor neuron diseases, or the Guillain-Barré syndrome, serum antibodies recognizing saccharide units, portion of oligosaccharides, or oligosaccharide chains, have been found. These antibodies are called anti-glycosphingolipid (GSL) or anti-ganglioside antibodies. However, the information on the aglycone carrying the hydrophilic oligosaccharide remains elusive. The absolute and unique association of GSL to the onset, development and symptomatology of the peripheral neuropathies could be misleading. Here, we report some thoughts on the matter.

  20. Diagnosis and new treatments in genetic neuropathies.

    Science.gov (United States)

    Reilly, M M; Shy, M E

    2009-12-01

    The genetic neuropathies are a clinically and genetically heterogeneous group of diseases of which the most common types are Charcot-Marie-Tooth disease (CMT), the hereditary sensory and autonomic neuropathies and the distal hereditary motor neuropathies. More than 30 causative genes have been described, making an accurate genetic diagnosis increasingly possible. Although no specific therapies are yet available, research into their pathogenesis has revolutionised our understanding of the peripheral nervous system and allowed the development of rational approaches to therapy. The first therapeutic trials in CMT are currently underway. This review will suggest an approach to the diagnosis of these disorders and provide an update on new therapies.

  1. Electrodiagnostic testing in diabetic neuropathy: Which limb?

    Science.gov (United States)

    Rota, E; Cocito, D

    2015-10-01

    Electrodiagnosis of subclinical diabetic neuropathies by nerve conduction studies remains challenging. The question arises about which nerves should be tested and what the best electrodiagnostic protocol to make an early diagnosis of diabetic neuropathies would be. On the basis of our findings and other evidence, which highlighted the remarkable prevalence of electrophysiological abnormalities in nerve conduction studies of the upper limbs, often in the presence of normal lower limb conduction parameters, we suggest that both ulnar and median nerves, in their motor and sensitive component, should be the two target nerves for electrodiagnostic protocols in diabetic neuropathies.

  2. Association of peripheral neuropathy with sleep-related breathing disorders in myotonic dystrophies

    Science.gov (United States)

    Banach, Marta; Antczak, Jakub; Rola, Rafał

    2017-01-01

    Background Myotonic dystrophy (DM) type 1 and type 2 are inherited diseases characterized by myotonia and myopathy. Additional symptoms include, among others, peripheral neuropathy and sleep-related breathing disorders (SRBDs). There is growing evidence for a complex association between DM1 and DM2, which was described in patients with diabetes mellitus and in the general population. In this study, we investigated whether there is an association between peripheral neuropathy and SRBDs also in the population of patients with DM. Methods The study included 16 patients with DM1 (mean age, 37.9±14.1 years; 20–69 years) and eight patients with DM2 (mean age, 47.6±14.1 years; 20–65 years), who underwent a sensory and motor nerve conduction study (NCS) and diagnostic screening for SRBDs. In both groups, the NCS parameters were correlated with respiratory parameters. Results In both groups, the amplitude of the ulnar sensory nerve action potential (SNAP) correlated with the mean arterial oxygen saturation (SaO2). In addition, in the DM2 group, the median SNAP correlated with the mean SaO2. In the DM1 group, the median SNAP and the distal motor latency (DML) of the ulnar nerve correlated with the apnea–hypopnea index, while the oxygen desaturation index correlated with the DML of the tibial nerve and with conduction velocity in the sural nerve. Conclusion Our results indicate a complex association between neuropathy and SRBDs in DM1 and DM2. Axonal degeneration may contribute to nocturnal hypoxemia and vice versa. Neuropathy may contribute to muscle weakness, which in turn may cause respiratory events. PMID:28138246

  3. Diabetic peripheral neuropathy: should a chaperone accompany our therapeutic approach?

    Science.gov (United States)

    Farmer, Kevin L; Li, Chengyuan; Dobrowsky, Rick T

    2012-10-01

    Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that is associated with axonal atrophy, demyelination, blunted regenerative potential, and loss of peripheral nerve fibers. The development and progression of DPN is due in large part to hyperglycemia but is also affected by insulin deficiency and dyslipidemia. Although numerous biochemical mechanisms contribute to DPN, increased oxidative/nitrosative stress and mitochondrial dysfunction seem intimately associated with nerve dysfunction and diminished regenerative capacity. Despite advances in understanding the etiology of DPN, few approved therapies exist for the pharmacological management of painful or insensate DPN. Therefore, identifying novel therapeutic strategies remains paramount. Because DPN does not develop with either temporal or biochemical uniformity, its therapeutic management may benefit from a multifaceted approach that inhibits pathogenic mechanisms, manages inflammation, and increases cytoprotective responses. Finally, exercise has long been recognized as a part of the therapeutic management of diabetes, and exercise can delay and/or prevent the development of painful DPN. This review presents an overview of existing therapies that target both causal and symptomatic features of DPN and discusses the role of up-regulating cytoprotective pathways via modulating molecular chaperones. Overall, it may be unrealistic to expect that a single pharmacologic entity will suffice to ameliorate the multiple symptoms of human DPN. Thus, combinatorial therapies that target causal mechanisms and enhance endogenous reparative capacity may enhance nerve function and improve regeneration in DPN if they converge to decrease oxidative stress, improve mitochondrial bioenergetics, and increase response to trophic factors.

  4. Genotype-phenotype correlations in Leber hereditary optic neuropathy.

    Science.gov (United States)

    Tońska, Katarzyna; Kodroń, Agata; Bartnik, Ewa

    2010-01-01

    Leber hereditary optic neuropathy (LHON), acute or subacute vision loss due to retinal ganglion cell death which in the long run leads to optic nerve atrophy is one of the most widely studied maternally inherited diseases caused by mutations in mitochondrial DNA. Although three common mutations, 11778G>A, 14484T>C or 3460G>A are responsible for over 90% of cases and affect genes encoding complex I subunits of the respiratory chain, their influence on bioenergetic properties of the cell is marginal and cannot fully explain the pathology of the disease. The following chain of events was proposed, based on biochemical and anatomical properties of retinal ganglion cells whose axons form the optic nerve: mitochondrial DNA mutations increase reactive oxygen species production in these sensitive cells, leading to caspase-independent apoptosis. As LHON is characterized by low penetrance and sex bias (men are affected about 5 times more frequently than women) the participation of the other factors-genetic and environmental-beside mtDNA mutations was studied. Mitochondrial haplogroups and smoking are some of the factors involved in the complex etiology of this disease.

  5. Genetic aspects of sodium channelopathy in small fiber neuropathy.

    Science.gov (United States)

    Hoeijmakers, J G J; Merkies, I S J; Gerrits, M M; Waxman, S G; Faber, C G

    2012-10-01

    Small fiber neuropathy (SFN) is a disorder typically dominated by neuropathic pain and autonomic dysfunction, in which the thinly myelinated Aδ-fibers and unmyelinated C-fibers are selectively injured. The diagnosis SFN is based on a reduced intraepidermal nerve fiber density and/or abnormal thermal thresholds in quantitative sensory testing. The etiologies of SFN are diverse, although no apparent cause is frequently seen. Recently, SCN9A-gene variants (single amino acid substitutions) have been found in ∼30% of a cohort of idiopathic SFN patients, producing gain-of-function changes in sodium channel Na(V)1.7, which is preferentially expressed in small diameter peripheral axons. Functional testing showed that these variants altered fast inactivation, slow inactivation or resurgent current and rendered dorsal root ganglion neurons hyperexcitable. In this review, we discuss the role of Na(V)1.7 in pain and highlight the molecular genetics and pathophysiology of SCN9A-gene variants in SFN. With increasing knowledge regarding the underlying pathophysiology in SFN, the development of specific treatment in these patients seems a logical target for future studies.

  6. Axon injury triggers EFA-6 mediated destabilization of axonal microtubules via TACC and doublecortin like kinase.

    Science.gov (United States)

    Chen, Lizhen; Chuang, Marian; Koorman, Thijs; Boxem, Mike; Jin, Yishi; Chisholm, Andrew D

    2015-09-04

    Axon injury triggers a series of changes in the axonal cytoskeleton that are prerequisites for effective axon regeneration. In Caenorhabditis elegans the signaling protein Exchange Factor for ARF-6 (EFA-6) is a potent intrinsic inhibitor of axon regrowth. Here we show that axon injury triggers rapid EFA-6-dependent inhibition of axonal microtubule (MT) dynamics, concomitant with relocalization of EFA-6. EFA-6 relocalization and axon regrowth inhibition require a conserved 18-aa motif in its otherwise intrinsically disordered N-terminal domain. The EFA-6 N-terminus binds the MT-associated proteins TAC-1/Transforming-Acidic-Coiled-Coil, and ZYG-8/Doublecortin-Like-Kinase, both of which are required for regenerative growth cone formation, and which act downstream of EFA-6. After injury TAC-1 and EFA-6 transiently relocalize to sites marked by the MT minus end binding protein PTRN-1/Patronin. We propose that EFA-6 acts as a bifunctional injury-responsive regulator of axonal MT dynamics, acting at the cell cortex in the steady state and at MT minus ends after injury.

  7. Linezolid-induced optic neuropathy

    Directory of Open Access Journals (Sweden)

    Divya Karuppannasamy

    2014-01-01

    Full Text Available Many systemic antimicrobials have been implicated to cause ocular adverse effects. This is especially relevant in multidrug therapy where more than one drug can cause a similar ocular adverse effect. We describe a case of progressive loss of vision associated with linezolid therapy. A 45-year-old male patient who was on treatment with multiple second-line anti-tuberculous drugs including linezolid and ethambutol for extensively drug-resistant tuberculosis (XDR-TB presented to us with painless progressive loss of vision in both eyes. Color vision was defective and fundus examination revealed optic disc edema in both eyes. Ethambutol-induced toxic optic neuropathy was suspected and tablet ethambutol was withdrawn. Deterioration of vision occurred despite withdrawal of ethambutol. Discontinuation of linezolid resulted in marked improvement of vision. Our report emphasizes the need for monitoring of visual function in patients on long-term linezolid treatment.

  8. Unilateral anterior ischemic optic neuropathy

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik

    2013-01-01

    The intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin, which is sensitive to blue light. Previous chromatic pupillometry studies have shown that the post-illumination response is considered an indicator of the melanopsin activation. The aim......-affected eyes, compared with the non-affected fellow eyes, suggesting dysfunction of the ipRGCs. Compared with the responses of the healthy controls, the blue light post-illumination pupil responses were similar in the affected eyes and increased in the fellow non-affected eyes. This suggests a possible...... of this study was to investigate the ipRGC mediated pupil response in patients with a unilateral non-arteritic anterior ischemic optic neuropathy (NAION). Consensual pupil responses during and after exposure to continuous 20 s blue (470 nm) or red (660 nm) light of high intensity (300 cd/m(2)) were recorded...

  9. Pathogenesis of Painful Diabetic Neuropathy

    Directory of Open Access Journals (Sweden)

    Amir Aslam

    2014-01-01

    Full Text Available The prevalence of diabetes is rising globally and, as a result, its associated complications are also rising. Painful diabetic neuropathy (PDN is a well-known complication of diabetes and the most common cause of all neuropathic pain. About one-third of all diabetes patients suffer from PDN. It has a huge effect on a person’s daily life, both physically and mentally. Despite huge advances in diabetes and neurology, the exact mechanism of pain causation in PDN is still not clear. The origin of pain could be in the peripheral nerves of the central nervous system. In this review, we discuss various possible mechanisms of the pathogenesis of pain in PDN. We discuss the role of hyperglycaemia in altering the physiology of peripheral nerves. We also describe central mechanisms of pain.

  10. Hereditary sensory and autonomic neuropathies.

    Science.gov (United States)

    Auer-Grumbach, Michaela

    2013-01-01

    Hereditary sensory and autonomic neuropathies (HSN/HSAN) are clinically and genetically heterogeneous disorders of the peripheral nervous system that predominantly affect the sensory and autonomic neurons. Hallmark features comprise not only prominent sensory signs and symptoms and ulcerative mutilations but also variable autonomic and motor disturbances. Autosomal dominant and autosomal recessive inheritance has been reported. Molecular genetics studies have identified disease-causing mutations in 11 genes. Some of the affected proteins have nerve-specific roles but underlying mechanisms have also been shown to involve sphingolipid metabolism, vesicular transport, structural integrity, and transcription regulation. Genetic and functional studies have substantially improved the understanding of the pathogenesis of the HSN/HSAN and will help to find preventive and causative therapies in the future.

  11. Enteric neuropathies: Yesterday, Today and Tomorrow.

    Science.gov (United States)

    De Giorgio, Roberto; Bianco, Francesca; Latorre, Rocco; Caio, Giacomo; Clavenzani, Paolo; Bonora, Elena

    2016-01-01

    Enteric neuropathy is a term indicating an impairment of the innervation supplying the gastrointestinal tract. The clinical phenotypes of the enteric neuropathies are the 'tip of the iceberg' of severe functional digestive diseases, such as intestinal pseudo-obstruction syndromes (e.g., chronic intestinal pseudo-obstruction). Despite progress acquired over the years, the pathogenetic mechanisms leading to enteric neuropathies are still far from being elucidated and the therapeutic approaches to these patients are mainly supportive, rather than curative.The purpose of this chapter is to review the advancements that have been done in the knowledge of enteric neuropathies identified in adult patients ('tomorrow'), going through where we currently are ('today') following a brief history of the major milestones on the pioneering discoveries in the field ('yesterday').

  12. Peripheral Neuropathy in Mouse Models of Diabetes.

    Science.gov (United States)

    Jolivalt, Corinne G; Frizzi, Katie E; Guernsey, Lucie; Marquez, Alex; Ochoa, Joseline; Rodriguez, Maria; Calcutt, Nigel A

    2016-09-01

    Peripheral neuropathy is a frequent complication of chronic diabetes that most commonly presents as a distal degenerative polyneuropathy with sensory loss. Around 20% to 30% of such patients may also experience neuropathic pain. The underlying pathogenic mechanisms are uncertain, and therapeutic options are limited. Rodent models of diabetes have been used for more than 40 years to study neuropathy and evaluate potential therapies. For much of this period, streptozotocin-diabetic rats were the model of choice. The emergence of new technologies that allow relatively cheap and routine manipulations of the mouse genome has prompted increased use of mouse models of diabetes to study neuropathy. In this article, we describe the commonly used mouse models of type 1 and type 2 diabetes, and provide protocols to phenotype the structural, functional, and behavioral indices of peripheral neuropathy, with a particular emphasis on assays pertinent to the human condition. © 2016 by John Wiley & Sons, Inc.

  13. Pharmacological Treatment Of Diabetic Peripheral Neuropathy

    OpenAIRE

    2015-01-01

    Pain modulation is a key treatment goal for diabetic peripheral neuropathy patients. Guidelines have recommended antidepressant, anticonvulsant, analgesic, and topical medications—both approved and off-label—to reduce pain in this population.

  14. Genetics Home Reference: small fiber neuropathy

    Science.gov (United States)

    ... particular ethnic groups? Genetic Changes Mutations in the SCN9A or SCN10A gene can cause small fiber neuropathy . ... pieces (the alpha subunits) of sodium channels. The SCN9A gene instructs the production of the alpha subunit ...

  15. [Herpes zoster-induced neuralgia (neuropathy)].

    Science.gov (United States)

    Maksimova, M Yu; Sineva, N A; Vodopyanov, N P

    2014-01-01

    Neuralgia (neuropathy) is the most common manifestation of herpes zoster (HZ). In spinal and cranial neuralgia, there are 3 types of pain: 1) spontaneous, persistent, burning pain; 2) intermittent sharp pain; 3) pain occurring with nonpainful stimulation. The skin exhibits areas of hypesthesia, anesthesia, and dysesthesia. Ophthalmic neuralgia (of the first branch of the trigeminal nerve) is encountered in 20% of HZ cases. HZ of the auricle and external auditory meatus concurrent with facial and vestibulocochlear neuropathy is diagnosed as Ramsay Hunt syndrome. Postherpetic neuralgia (neuropathy) is characterized by pain present for 3 months or more after the appearance of herpetic eruptions. Combined therapy involving the earlier use of antiviral agents, tricyclic antidepressants, analgesics, and neuromidine is the most effective option for HZ-induced neuralgia (neuropathy).

  16. INHERITED NEUROPATHIES: CLINICAL OVERVIEW AND UPDATE

    Science.gov (United States)

    KLEIN, CHRISTOPHER J.; DUAN, XIAOHUI; SHY, MICHAEL E.

    2014-01-01

    Inherited neuropathy is a group of common neurologic disorders with heterogeneous clinical presentations and genetic causes. Detailed neuromuscular evaluations, including nerve conduction studies, laboratory testing, and histopathologic examination, can assist in identification of the inherited component beyond family history. Genetic testing increasingly enables definitive diagnosis of specific inherited neuropathies. Diagnosis, however, is often complex, and neurologic disability may have both genetic and acquired components in individual patients. The decision of which genetic test to order or whether to order genetic tests is often complicated, and the strategies to maximize the value of testing are evolving. Apart from rare inherited metabolic neuropathies, treatment approaches remain largely supportive. We provide a clinical update of the various types of inherited neuropathies, their differential diagnoses, and distinguishing clinical features (where available). A framework is provided for clinical evaluations, including the inheritance assessment, electrophysiologic examinations, and specific genetic tests. PMID:23801417

  17. Anesthesia Management in Diabetic Cardiovascular Autonomic Neuropathy

    OpenAIRE

    Feride Karacaer

    2016-01-01

    Cardiovascular autonomic neuropathy is frequently observed in patients with diabetes mellitus and encompasses damage to the autonomic nerve fibers, resulting in abnormalities in heart rate control and vascular dynamics. There is an increased mortality and morbidity rate among these patients. A series of cardiovascular reflex tests known as Ewing's battery tests are used for diagnosis cardiac autonomic neuropathy and provide valuable information to the clinical assessment of these patients. As...

  18. Leber hereditary optic neuropathy mimicking neuromyelitis optica.

    Science.gov (United States)

    McClelland, Collin M; Van Stavern, Gregory P; Tselis, Alex C

    2011-09-01

    Leber hereditary optic neuropathy (LHON) is rarely associated with multiple sclerosis-like features. We present a case of a 65-year-old African American woman with LHON masquerading as neuromyelitis optica (NMO). We highlight the features of the clinical examination and MRI that were suggestive of an alternative diagnosis and review the literature regarding LHON and multiple sclerosis. The diagnosis of LHON should be considered in all cases of acute or subacute bilateral optic neuropathy, including presumed seronegative NMO.

  19. Sensory neuropathy with low-dose pyridoxine.

    Science.gov (United States)

    Parry, G J; Bredesen, D E

    1985-10-01

    We describe 16 patients with neuropathy associated with pyridoxine abuse. The clinical picture of a pure sensory central-peripheral distal axonopathy was consistent. Pyridoxine dose was 0.2 to 5 g/d, and duration of consumption before symptoms was inversely proportional to the daily intake. In all patients with adequate follow-up, improvement followed discontinuation of pyridoxine. The ready availability of up to 1-gram tablets makes it likely that this neuropathy will continue to be seen.

  20. [Pyridoxine neuropathies. Review of the literature].

    Science.gov (United States)

    Dordain, G; Deffond, D

    1994-01-01

    Daily needs of vitamin B6 are very low (2 mg per day) and widely covered by normal feeding. Pyridoxine deficiencies are exceptional (congenital metabolic abnormalities, drug or toxic-induced perturbations). First described in animal models, human cases of neuropathy had been encountered in the "megavitamin"-syndrome. They are confirmed by rare case-reports of very high doses given in toxic indication. Sensory peripheral neuropathies can also occur with lower doses taken over a long period of time.

  1. Blood pressure regulation in diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1985-01-01

    experimental situations insufficient contraction of resistance vessels has been demonstrated. The vasoconstrictor defects demonstrated are of a magnitude sufficient to account for the prevailing hypotension. Furthermore, during exercise cardiac output is low in patients with autonomic neuropathy, a finding...... blood pressure fall ensues in patients with autonomic neuropathy, probably due to excessive muscular vasodilation. It is unresolved why blood pressure regulation is intact during hypoglycemia and severely impaired--at similar catecholamine concentrations--during epinephrine infusions....

  2. How Schwann Cells Sort Axons: New Concepts.

    Science.gov (United States)

    Feltri, M Laura; Poitelon, Yannick; Previtali, Stefano Carlo

    2016-06-01

    Peripheral nerves contain large myelinated and small unmyelinated (Remak) fibers that perform different functions. The choice to myelinate or not is dictated to Schwann cells by the axon itself, based on the amount of neuregulin I-type III exposed on its membrane. Peripheral axons are more important in determining the final myelination fate than central axons, and the implications for this difference in Schwann cells and oligodendrocytes are discussed. Interestingly, this choice is reversible during pathology, accounting for the remarkable plasticity of Schwann cells, and contributing to the regenerative potential of the peripheral nervous system. Radial sorting is the process by which Schwann cells choose larger axons to myelinate during development. This crucial morphogenetic step is a prerequisite for myelination and for differentiation of Remak fibers, and is arrested in human diseases due to mutations in genes coding for extracellular matrix and linkage molecules. In this review we will summarize progresses made in the last years by a flurry of reverse genetic experiments in mice and fish. This work revealed novel molecules that control radial sorting, and contributed unexpected ideas to our understanding of the cellular and molecular mechanisms that control radial sorting of axons.

  3. Epigenetic regulation of axon and dendrite growth

    Directory of Open Access Journals (Sweden)

    Ephraim F Trakhtenberg

    2012-03-01

    Full Text Available Neuroregenerative therapies for central nervous system (CNS injury, neurodegenerative disease, or stroke require axons of damaged neurons to grow and reinnervate their targets. However, mature mammalian CNS neurons do not regenerate their axons, limiting recovery in these diseases (Yiu and He, 2006. CNS’ regenerative failure may be attributable to the development of an inhibitory CNS environment by glial-associated inhibitory molecules (Yiu and He, 2006, and by various cell-autonomous factors (Sun and He, 2010. Intrinsic axon growth ability also declines developmentally (Li et al., 1995; Goldberg et al., 2002; Bouslama-Oueghlani et al., 2003; Blackmore and Letourneau, 2006 and is dependent on transcription (Moore et al., 2009. Although neurons’ intrinsic capacity for axon growth may depend in part on the panoply of expressed transcription factors (Moore and Goldberg, 2011, epigenetic factors such as the accessibility of DNA and organization of chromatin are required for downstream genes to be transcribed. Thus a potential approach to overcoming regenerative failure focuses on the epigenetic mechanisms regulating regenerative gene expression in the CNS. Here we review molecular mechanisms regulating the epigenetic state of DNA through chromatin modifications, their implications for regulating axon and dendrite growth, and important new directions for this field of study.

  4. Protein phosphorylation: Localization in regenerating optic axons

    Energy Technology Data Exchange (ETDEWEB)

    Larrivee, D. (Cornell Univ. Medical College, New York, NY (USA))

    1990-09-01

    A number of axonal proteins display changes in phosphorylation during goldfish optic nerve regeneration. (1) To determine whether the phosphorylation of these proteins was closely linked to their synthesis in the retinal ganglion cell body, cycloheximide was injected intraocularly into goldfish whose optic nerves had been regenerating for 3 weeks. Cycloheximide reduced the incorporation of (3H)proline and 32P orthophosphate into total nerve protein by 84% and 46%, respectively. Of the 20 individual proteins examined, 17 contained less than 15% of the (3H)proline label measured in corresponding controls, whereas 18 proteins contained 50% or more of the 32P label, suggesting that phosphorylation was largely independent of synthesis. (2) To determine whether the proteins were phosphorylated in the ganglion cell axons, axonal transport of proteins was blocked by intraocular injection of vincristine. Vincristine reduced (3H)proline labeling of total protein by 88% and 32P labeling by 49%. Among the individual proteins (3H)proline labeling was reduced by 90% or more in 18 cases but 32P labeling was reduced only by 50% or less. (3) When 32P was injected into the cranial cavity near the ends of the optic axons, all of the phosphoproteins were labeled more intensely in the optic tract than in the optic nerve. These results suggest that most of the major phosphoproteins that undergo changes in phosphorylation in the course of regeneration are phosphorylated in the optic axons.

  5. Emerging Mitochondrial Therapeutic Targets in Optic Neuropathies.

    Science.gov (United States)

    Lopez Sanchez, M I G; Crowston, J G; Mackey, D A; Trounce, I A

    2016-09-01

    Optic neuropathies are an important cause of blindness worldwide. The study of the most common inherited mitochondrial optic neuropathies, Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) has highlighted a fundamental role for mitochondrial function in the survival of the affected neuron-the retinal ganglion cell. A picture is now emerging that links mitochondrial dysfunction to optic nerve disease and other neurodegenerative processes. Insights gained from the peculiar susceptibility of retinal ganglion cells to mitochondrial dysfunction are likely to inform therapeutic development for glaucoma and other common neurodegenerative diseases of aging. Despite it being a fast-evolving field of research, a lack of access to human ocular tissues and limited animal models of mitochondrial disease have prevented direct retinal ganglion cell experimentation and delayed the development of efficient therapeutic strategies to prevent vision loss. Currently, there are no approved treatments for mitochondrial disease, including optic neuropathies caused by primary or secondary mitochondrial dysfunction. Recent advances in eye research have provided important insights into the molecular mechanisms that mediate pathogenesis, and new therapeutic strategies including gene correction approaches are currently being investigated. Here, we review the general principles of mitochondrial biology relevant to retinal ganglion cell function and provide an overview of the major optic neuropathies with mitochondrial involvement, LHON and ADOA, whilst highlighting the emerging link between mitochondrial dysfunction and glaucoma. The pharmacological strategies currently being trialed to improve mitochondrial dysfunction in these optic neuropathies are discussed in addition to emerging therapeutic approaches to preserve retinal ganglion cell function.

  6. HISTOMORPHOMETRIC CHARACTERISTICS AND PATHOGENIC MECHANISM OF PERONEAL NERVE NEUROPATHY IN EXPERIMENTAL FRACTIONAL LOWER LEG LENGTHENING

    Directory of Open Access Journals (Sweden)

    T. N. Varsegova

    2016-01-01

    Full Text Available Purpose – to study histomorphometric characteristics and pathogenic mechanism of peroneal nerve neuropathy in experimental lower leg lengthening by one millimeter per day in four increments. Methods. The authors performed lengthening of lower leg in 12 adult mongrel dogs at 14-15% of initial length by Ilizarov technique. 28 days after the leg distraction, 30 days after its fixation in the device and 30 days after the Ilizarov fixator dismounting the authors withdrew the animals from the experiment. Peroneal nerve portions were examined using light microscopy, histomorphometry of the full-color images of the giant epoxy semifine sections stained with methylene blue and diamond fuchsin. Results. Planimetric investigation demonstrated 15% decrease (p<0.05 in the total area of nerve fiber bundles after distraction confirming transverse contraction of intrafascicular content. Fibrosis, increased cellularity of epineurium as well as the decrease in adipocyte number and size was observed in result of distraction and fixation. Neuropathy of the peroneal nerve was observed in one of the 12 animals – more than 80% of myelinated fibers demonstrated destructive changes, the large arteries of epineurium demonstrated obliterated lumina, part of arteries had necrobiotic changes in the cellular elements of the walls. In the remaining animals the proportion of the transformed myelinated fibers in the experiment time frame amounted to 6.0±1.4%, 4.3±1.3% and 4.2±0.4% (normally: 1.9±0.3%, no marked vascular damage was observed, the number of epineural vascular modules increased up to 6.0±1.5 (contralaterally – up to 4.0±1.6, the number of endoneural microvessels was increased at 35.5%, 10.9% and 38.9% (p<0.05 in respect of intact norm (141.8±8.7 per 1 mm2. Reduced proportion of capillaries with open lumina confirmed vasomotion disorder. The changes analysis in the distribution of myelinated fibers by diameter and mean size indicates the distinct axonal

  7. Lack of GDAP1 induces neuronal calcium and mitochondrial defects in a knockout mouse model of charcot-marie-tooth neuropathy.

    Science.gov (United States)

    Barneo-Muñoz, Manuela; Juárez, Paula; Civera-Tregón, Azahara; Yndriago, Laura; Pla-Martin, David; Zenker, Jennifer; Cuevas-Martín, Carmen; Estela, Anna; Sánchez-Aragó, María; Forteza-Vila, Jerónimo; Cuezva, José M; Chrast, Roman; Palau, Francesc

    2015-04-01

    Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2), axonal dominant (CMT2K) and demyelinating recessive (CMT4A) forms of Charcot-Marie-Tooth (CMT) neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE) upon mobilization of endoplasmic reticulum (ER) Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs) in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria-endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.

  8. Lack of GDAP1 induces neuronal calcium and mitochondrial defects in a knockout mouse model of charcot-marie-tooth neuropathy.

    Directory of Open Access Journals (Sweden)

    Manuela Barneo-Muñoz

    2015-04-01

    Full Text Available Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2, axonal dominant (CMT2K and demyelinating recessive (CMT4A forms of Charcot-Marie-Tooth (CMT neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE upon mobilization of endoplasmic reticulum (ER Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria-endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.

  9. Clinical diagnosis of diabetic polyneuropathy with the diabetic neuropathy symptom and diabetic neuropathy examination scores

    NARCIS (Netherlands)

    Meijer, J.W.; Lefrandt, J.D.; Links, T.P.; Smit, J.A.; Stewart, R.E.; van der Hoeven, J.H.; Hoogenberg, K.

    2003-01-01

    OBJECTIVE - To evaluate the discriminative power of the Diabetic Neuropathy Symptom (DNS) and Diabetic Neuropathy Examination (DNE) scores for diagnosing diabetic polyneuropathy (PNP), as well as their relation with cardiovascular autonomic function testing (cAFT) and electro-diagnostic studies (EDS

  10. Automated Axon Counting in Rodent Optic Nerve Sections with AxonJ

    Science.gov (United States)

    Zarei, Kasra; Scheetz, Todd E.; Christopher, Mark; Miller, Kathy; Hedberg-Buenz, Adam; Tandon, Anamika; Anderson, Michael G.; Fingert, John H.; Abràmoff, Michael David

    2016-05-01

    We have developed a publicly available tool, AxonJ, which quantifies the axons in optic nerve sections of rodents stained with paraphenylenediamine (PPD). In this study, we compare AxonJ’s performance to human experts on 100x and 40x images of optic nerve sections obtained from multiple strains of mice, including mice with defects relevant to glaucoma. AxonJ produced reliable axon counts with high sensitivity of 0.959 and high precision of 0.907, high repeatability of 0.95 when compared to a gold-standard of manual assessments and high correlation of 0.882 to the glaucoma damage staging of a previously published dataset. AxonJ allows analyses that are quantitative, consistent, fully-automated, parameter-free, and rapid on whole optic nerve sections at 40x. As a freely available ImageJ plugin that requires no highly specialized equipment to utilize, AxonJ represents a powerful new community resource augmenting studies of the optic nerve using mice.

  11. Diverse modes of axon elaboration in the developing neocortex.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available The development of axonal arbors is a critical step in the establishment of precise neural circuits, but relatively little is known about the mechanisms of axonal elaboration in the neocortex. We used in vivo two-photon time-lapse microscopy to image axons in the neocortex of green fluorescent protein-transgenic mice over the first 3 wk of postnatal development. This period spans the elaboration of thalamocortical (TC and Cajal-Retzius (CR axons and cortical synaptogenesis. Layer 1 collaterals of TC and CR axons were imaged repeatedly over time scales ranging from minutes up to days, and their growth and pruning were analyzed. The structure and dynamics of TC and CR axons differed profoundly. Branches of TC axons terminated in small, bulbous growth cones, while CR axon branch tips had large growth cones with numerous long filopodia. TC axons grew rapidly in straight paths, with frequent interstitial branch additions, while CR axons grew more slowly along tortuous paths. For both types of axon, new branches appeared at interstitial sites along the axon shaft and did not involve growth cone splitting. Pruning occurred via retraction of small axon branches (tens of microns, at both CR and TC axons or degeneration of large portions of the arbor (hundreds of microns, for TC axons only. The balance between growth and retraction favored overall growth, but only by a slight margin. Given the identical layer 1 territory upon which CR and TC axons grow, the differences in their structure and dynamics likely reflect distinct intrinsic growth programs for axons of long projection neurons versus local interneurons.

  12. Differences in excitability between median and superficial radial sensory axons.

    Science.gov (United States)

    Fujimaki, Yumi; Kanai, Kazuaki; Misawa, Sonoko; Shibuya, Kazumoto; Isose, Sagiri; Nasu, Saiko; Sekiguchi, Yukari; Ohmori, Shigeki; Noto, Yu-ichi; Kugio, Yumiko; Shimizu, Toshio; Matsubara, Shiro; Lin, Cindy S Y; Kuwabara, Satoshi

    2012-07-01

    The aim of this study was to investigate differences in excitability properties of human median and superficial radial sensory axons (e.g., axons innervating the glabrous and hairy skin in the hand). Previous studies have shown that excitability properties differ between motor and sensory axons, and even among sensory axons between median and sural sensory axons. In 21 healthy subjects, threshold tracking was used to examine excitability indices such as strength-duration time constant, threshold electrotonus, supernormality, and threshold change at the 0.2 ms inter-stimulus interval in latent addition. In addition, threshold changes induced by ischemia for 10 min were compared between median and superficial radial sensory axons. Compared with radial sensory axons, median axons showed shorter strength-duration time constant, greater threshold changes in threshold electrotonus (fanning-out), greater supernormality, and smaller threshold changes in latent addition. Threshold changes in both during and after ischemia were greater for median axons. These findings suggest that membrane potential in human median sensory axons is more negative than in superficial radial axons, possibly due to greater activity of electrogenic Na(+)/K(+) pump. These results may reflect adaptation to impulses load carried by median axons that would be far greater with a higher frequency. Biophysical properties are not identical in different human sensory axons, and therefore their responses to disease may differ. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Neural Progenitor Cells Promote Axonal Growth and Alter Axonal mRNA Localization in Adult Neurons

    Science.gov (United States)

    Merianda, Tanuja T.; Jin, Ying

    2017-01-01

    Abstract The inhibitory environment of the spinal cord and the intrinsic properties of neurons prevent regeneration of axons following CNS injury. However, both ascending and descending axons of the injured spinal cord have been shown to regenerate into grafts of embryonic neural progenitor cells (NPCs). Previous studies have shown that grafts composed of glial-restricted progenitors (GRPs) and neural-restricted progenitors (NRPs) can provide a permissive microenvironment for axon growth. We have used cocultures of adult rat dorsal root ganglion (DRG) neurons together with NPCs, which have shown significant enhancement of axon growth by embryonic rat GRP and GRPs/NRPs, both in coculture conditions and when DRGs are exposed to conditioned medium from the NPC cultures. This growth-promoting effect of NPC-conditioned medium was also seen in injury-conditioned neurons. DRGs cocultured with GRPs/NRPs showed altered expression of regeneration-associated genes at transcriptional and post-transcriptional levels. We found that levels of GAP-43 mRNA increased in DRG cell bodies and axons. However, hepcidin antimicrobial peptide (HAMP) mRNA decreased in the cell bodies of DRGs cocultured with GRPs/NRPs, which is distinct from the increase in cell body HAMP mRNA levels seen in DRGs after injury conditioning. Endogenous GAP-43 and β-actin mRNAs as well as reporter RNAs carrying axonally localizing 3'UTRs of these transcripts showed significantly increased levels in distal axons in the DRGs cocultured with GRPs/NRPs. These results indicate that axon growth promoted by NPCs is associated not only with enhanced transcription of growth-associated genes but also can increase localization of some mRNAs into growing axons. PMID:28197547

  14. Neural Progenitor Cells Promote Axonal Growth and Alter Axonal mRNA Localization in Adult Neurons.

    Science.gov (United States)

    Merianda, Tanuja T; Jin, Ying; Kalinski, Ashley L; Sahoo, Pabitra K; Fischer, Itzhak; Twiss, Jeffery L

    2017-01-01

    The inhibitory environment of the spinal cord and the intrinsic properties of neurons prevent regeneration of axons following CNS injury. However, both ascending and descending axons of the injured spinal cord have been shown to regenerate into grafts of embryonic neural progenitor cells (NPCs). Previous studies have shown that grafts composed of glial-restricted progenitors (GRPs) and neural-restricted progenitors (NRPs) can provide a permissive microenvironment for axon growth. We have used cocultures of adult rat dorsal root ganglion (DRG) neurons together with NPCs, which have shown significant enhancement of axon growth by embryonic rat GRP and GRPs/NRPs, both in coculture conditions and when DRGs are exposed to conditioned medium from the NPC cultures. This growth-promoting effect of NPC-conditioned medium was also seen in injury-conditioned neurons. DRGs cocultured with GRPs/NRPs showed altered expression of regeneration-associated genes at transcriptional and post-transcriptional levels. We found that levels of GAP-43 mRNA increased in DRG cell bodies and axons. However, hepcidin antimicrobial peptide (HAMP) mRNA decreased in the cell bodies of DRGs cocultured with GRPs/NRPs, which is distinct from the increase in cell body HAMP mRNA levels seen in DRGs after injury conditioning. Endogenous GAP-43 and β-actin mRNAs as well as reporter RNAs carrying axonally localizing 3'UTRs of these transcripts showed significantly increased levels in distal axons in the DRGs cocultured with GRPs/NRPs. These results indicate that axon growth promoted by NPCs is associated not only with enhanced transcription of growth-associated genes but also can increase localization of some mRNAs into growing axons.

  15. MR neurography in ulnar neuropathy as surrogate parameter for the presence of disseminated neuropathy.

    Directory of Open Access Journals (Sweden)

    Philipp Bäumer

    Full Text Available PURPOSE: Patients with ulnar neuropathy of unclear etiology occasionally present with lesion extension from elbow to upper arm level on MRI. This study investigated whether MRI thereby distinguishes multifocal neuropathy from focal-compressive neuropathy at the elbow. METHODS: This prospective study was approved by the institutional ethics committee and written informed consent was obtained from all participants. 122 patients with ulnar mononeuropathy of undetermined localization and etiology by clinical and electrophysiological examination were assessed by MRI at upper arm and elbow level using T2-weighted fat-saturated sequences at 3T. Twenty-one patients were identified with proximal ulnar nerve lesions and evaluated for findings suggestive of disseminated neuropathy (i subclinical lesions in other nerves, (ii unfavorable outcome after previous decompressive elbow surgery, and (iii subsequent diagnosis of inflammatory or other disseminated neuropathy. Two groups served as controls for quantitative analysis of nerve-to-muscle signal intensity ratios: 20 subjects with typical focal ulnar neuropathy at the elbow and 20 healthy subjects. RESULTS: In the group of 21 patients with proximal ulnar nerve lesion extension, T2-w ulnar nerve signal was significantly (p<0.001 higher at upper arm level than in both control groups. A cut-off value of 1.92 for maximum nerve-to-muscle signal intensity ratio was found to be sensitive (86% and specific (100% to discriminate this group. Ten patients (48% exhibited additional T2-w lesions in the median and/or radial nerve. Another ten (48% had previously undergone elbow surgery without satisfying outcome. Clinical follow-up was available in 15 (71% and revealed definitive diagnoses of multifocal neuropathy of various etiologies in four patients. In another eight, diagnoses could not yet be considered definitive but were consistent with multifocal neuropathy. CONCLUSION: Proximal ulnar nerve T2 lesions at upper

  16. Myelin-associated glycoprotein and its axonal receptors.

    Science.gov (United States)

    Schnaar, Ronald L; Lopez, Pablo H H

    2009-11-15

    Myelin-associated glycoprotein (MAG) is expressed on the innermost myelin membrane wrap, directly apposed to the axon surface. Although it is not required for myelination, MAG enhances long-term axon-myelin stability, helps to structure nodes of Ranvier, and regulates the axon cytoskeleton. In addition to its role in axon-myelin stabilization, MAG inhibits axon regeneration after injury; MAG and a discrete set of other molecules on residual myelin membranes at injury sites actively signal axons to halt elongation. Both the stabilizing and the axon outgrowth inhibitory effects of MAG are mediated by complementary MAG receptors on the axon surface. Two MAG receptor families have been described, sialoglycans (specifically gangliosides GD1a and GT1b) and Nogo receptors (NgRs). Controversies remain about which receptor(s) mediates which of MAG's biological effects. Here we review the findings and challenges in associating MAG's biological effects with specific receptors.

  17. [Current issues in hereditary neuropathies].

    Science.gov (United States)

    Lacour, A

    2013-12-01

    This short review highlights five studies published in 2012 in the field of Charcot-Marie-Tooth disease (CMT) and transthyretin familial amyloid neuropathies (TTR-FAN). Regarding CMT, an Australian pediatric study shows the high prevalence of impaired speech perception and hearing disability in children with CMT1 or CMT2 with normal or near normal audiometry (Rance et al., 2012). In a second study, the clinical and electrophysiological characteristics of 14 patients with CMT4C due to mutations in SH3TC2 gene are described (Yger et al., 2012). The 3 clinical hallmarks of CMT4C patients in this French cohort are the high prevalence of scoliosis, the proximal motor weakness and the cranial nerves involvement. Concerning TTR-FAN, the first data from French and international registries are reported (Adams et al., 2012; Coelho et al., 2013) and a phase II trial describes the results of taurourodeoxycholic acid and doxycycline treatment (Obici et al., 2012).

  18. Genetics Home Reference: hereditary sensory and autonomic neuropathy type V

    Science.gov (United States)

    ... Conditions HSAN5 hereditary sensory and autonomic neuropathy type V Enable Javascript to view the expand/collapse boxes. ... All Description Hereditary sensory and autonomic neuropathy type V ( HSAN5 ) is a condition that primarily affects the ...

  19. Pediatric sciatic neuropathies due to unusual vascular causes

    NARCIS (Netherlands)

    Srinivasan, Jayashri; Escolar, Diane; Ryan, Monique; Darras, Basil; Jones, H. Royden

    2008-01-01

    Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies dem

  20. Pediatric sciatic neuropathies due to unusual vascular causes

    NARCIS (Netherlands)

    Srinivasan, Jayashri; Escolar, Diane; Ryan, Monique; Darras, Basil; Jones, H. Royden

    Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies

  1. [The role of the immune system in hereditary demyelinating neuropathies].

    Science.gov (United States)

    Mäurer, M; Toyka, K V; Martini, R

    2005-06-01

    Hereditary neuropathies, e.g., Charcot-Marie-Tooth (CMT) disease, are inherited diseases of the peripheral nervous system causing chronic progressive motor and sensory dysfunction. Most neuropathies are due to mutations in myelin genes such as PMP22, P0, and the gap junction protein Cx32. Myelin mutant mice are regarded as suitable animal models for several forms of hereditary neuropathies and are important neurobiological tools for the evaluation of pathogenetic and therapeutic concepts in hereditary neuropathies. Using these animal models we could recently show that the immune system is involved in the pathogenesis of hereditary neuropathies. Due to the phenotypic similarities we also consider the immune system important for human inherited neuropathies, in particular since several case reports demonstrate a beneficial effect of immune therapies in patients with hereditary neuropathies. In this review we compare findings from animal models and human disease to elucidate the role of the immune system in hereditary neuropathies.

  2. The pathophysiology of axonal transport in alzheimer’s disease

    OpenAIRE

    Vicario Orri, Elena; Opazo, Carlos; Muñoz López, Francisco José, 1964-

    2015-01-01

    Neurons communicate in the nervous system by carrying out information along the length of their axons to finally transmit it at the synapse. Proper function of axons and axon terminals relies on the transport of proteins, organelles, vesicles, and other elements from the site of synthesis in the cell body. Conversely, neurotrophins secreted from axonal targets and other components at nerve terminals need to travel toward the cell body for clearance. Molecular motors, namely kinesins and dynei...

  3. Internodal function in normal and regenerated mammalian axons

    DEFF Research Database (Denmark)

    Moldovan, M; Krarup, C

    2007-01-01

    AIM: Following Wallerian degeneration, peripheral myelinated axons have the ability to regenerate and, given a proper pathway, establish functional connections with targets. In spite of this capacity, the clinical outcome of nerve regeneration remains unsatisfactory. Early studies have found...... that internodes play an active role in axonal function. RESULTS: By investigating internodal contribution to axonal excitability we have found evidence that axonal function may be permanently compromised in regenerated nerves. Furthermore, we illustrate that internodal function is also abnormal in regenerated...

  4. In vivo imaging of alphaherpesvirus infection reveals synchronized activity dependent on axonal sorting of viral proteins.

    Science.gov (United States)

    Granstedt, Andrea E; Bosse, Jens B; Thiberge, Stephan Y; Enquist, Lynn W

    2013-09-10

    A clinical hallmark of human alphaherpesvirus infections is peripheral pain or itching. Pseudorabies virus (PRV), a broad host range alphaherpesvirus, causes violent pruritus in many different animals, but the mechanism is unknown. Previous in vitro studies have shown that infected, cultured peripheral nervous system (PNS) neurons exhibited aberrant electrical activity after PRV infection due to the action of viral membrane fusion proteins, yet it is unclear if such activity occurs in infected PNS ganglia in living animals and if it correlates with disease symptoms. Using two-photon microscopy, we imaged autonomic ganglia in living mice infected with PRV strains expressing GCaMP3, a genetically encoded calcium indicator, and used the changes in calcium flux to monitor the activity of many neurons simultaneously with single-cell resolution. Infection with virulent PRV caused these PNS neurons to fire synchronously and cyclically in highly correlated patterns among infected neurons. This activity persisted even when we severed the presynaptic axons, showing that infection-induced firing is independent of input from presynaptic brainstem neurons. This activity was not observed after infections with an attenuated PRV recombinant used for circuit tracing or with PRV mutants lacking either viral glycoprotein B, required for membrane fusion, or viral membrane protein Us9, required for sorting virions and viral glycoproteins into axons. We propose that the viral fusion proteins produced by virulent PRV infection induce electrical coupling in unmyelinated axons in vivo. This action would then give rise to the synchronous and cyclical activity in the ganglia and contribute to the characteristic peripheral neuropathy.

  5. Muscle cramp in Machado-Joseph disease: altered motor axonal excitability properties and mexiletine treatment.

    Science.gov (United States)

    Kanai, Kazuaki; Kuwabara, Satoshi; Arai, Kimihito; Sung, Jia-Ying; Ogawara, Kazue; Hattori, Takamichi

    2003-04-01

    Machado-Joseph disease is one of the most common hereditary spinocerebellar degenerative disorders with a wide range of clinical manifestations. Pathology studies have shown mild to moderate loss of anterior horn cells and, in terms of spinal pathology, Machado-Joseph disease is regarded as a type of lower motoneuron disease. Muscle cramps are often associated with lower motoneuron disorders, but features of cramps in Machado-Joseph disease patients have never been studied. We investigated the incidence and nature of muscle cramps in Machado-Joseph disease patients, the excitability properties of motor axons [strength-duration time constant (tau(SD)), threshold electrotonus, refractoriness and supernormality] using threshold tracking and the effects of mexiletine hydrochloride on those cramps. Of 20 consecutive patients, 16 (80%) had frequent, severe muscle cramps in the legs, trunk or arms that disturbed their daily activities. The frequency of pathological muscle cramps was similar to that for patients with amyotrophic lateral sclerosis (68%) and higher than those for patients with spinal muscular atrophy (33%) or peripheral axonal neuropathy (24%). Threshold-tracking studies showed that tau(SD), which in part reflects Na(+) conductance at the resting membrane potential, was significantly greater in the Machado-Joseph disease patients than in normal subjects; severe muscle cramps were associated with a longer tau(SD). Threshold electrotonus, refractoriness and supernormality were not significantly different between Machado-Joseph disease patients and normal subjects. Eight Machado-Joseph disease patients with severe cramps, who received mexiletine treatment, experienced nearly complete relief with a partial normalization of tau(SD) (P = 0.08). Muscle cramps are a very frequent and disabling factor in Machado-Joseph disease. Pathological muscle cramps responded well to mexiletine treatment, and this is consistent with the hypothesis that they are caused by an

  6. Modeling molecular mechanisms in the axon

    Science.gov (United States)

    de Rooij, R.; Miller, K. E.; Kuhl, E.

    2017-03-01

    Axons are living systems that display highly dynamic changes in stiffness, viscosity, and internal stress. However, the mechanistic origin of these phenomenological properties remains elusive. Here we establish a computational mechanics model that interprets cellular-level characteristics as emergent properties from molecular-level events. We create an axon model of discrete microtubules, which are connected to neighboring microtubules via discrete crosslinking mechanisms that obey a set of simple rules. We explore two types of mechanisms: passive and active crosslinking. Our passive and active simulations suggest that the stiffness and viscosity of the axon increase linearly with the crosslink density, and that both are highly sensitive to the crosslink detachment and reattachment times. Our model explains how active crosslinking with dynein motors generates internal stresses and actively drives axon elongation. We anticipate that our model will allow us to probe a wide variety of molecular phenomena—both in isolation and in interaction—to explore emergent cellular-level features under physiological and pathological conditions.

  7. A Microfluidics Approach to Investigate Axon Guidance

    Science.gov (United States)

    2007-03-26

    coat the substrate with PLL. The cells of one dissociated embryonic spinal cord was re-suspended in 3 µl of freshly-prepared Modified Frog Ringer’s...Surround repulsion of spinal sensory axons in higher vertebrate embryos . Neuron 18, 889-897 (1997). 8. Colamarino, S. & Tessier-Lavigne, M. The

  8. Clinical Profile of Peripheral Neuropathy in Leprosy.

    Science.gov (United States)

    Sarker, U K; Uddin, M J; Chowdhury, R; Roy, N; Bhattacharjee, M; Roy, J

    2015-10-01

    The objectives of the study were to see the association of peripheral neuropathy in leprosy and to find out the clinical profile of peripheral neuropathy and disability status in leprosy. It was descriptive type of cross sectional study was conducted among the cases of leprosy attended in the out-patient departments of neurology, Mymensingh Medical College Hospital (MMCH) and Mymensingh tuberculosis and leprosy hospital that fulfilled the inclusion criteria were included in this study, during the study period of January 2010 to December 2011.In this study of 62 cases revealed that leprosy is more common in male (71%) people and 21% leprosy patient had contact with known case of leprosy. Leprosy causes peripheral neuropathy (61.3%). Duration of occurrence of peripheral neuropathy was prolonged (>6 month) in most of the patients (47.4%) and the disease progression was also slow (63.2%). Numbness was complained by 89.4% patients and 65.8% subjects complained of weakness of limbs. Deformities and ulcers were present in 26.3% and 50% of patients respectively. Ulnar nerve (43.6%), Lateral popliteal nerve (41.9%), Posterior tibial nerve (41.9%) and Great auricular nerve (17.7%) were the most commonly involved thickened peripheral nerves. The rate of visible physical impairment (WHO Grade 2 disability) among people affected by leprosy in feet was 27.4% and in hands was 16.1%. The position and vibration sense was found to normal all patients of peripheral neuropathy.

  9. Genetic Basis of Mitochondrial Optic Neuropathies.

    Science.gov (United States)

    Maresca, A; Caporali, L; Strobbe, D; Zanna, C; Malavolta, D; La Morgia, C; Valentino, M L; Carelli, V

    2014-01-01

    Over two decades have elapsed since the first mtDNA point mutation was associated with Leber's hereditary optic neuropathy (LHON) in 1988. We have subsequently witnessed a substantial understanding of the molecular basis of hereditary optic neuropathies, as well as of their clinical features and pathogenic mechanisms. It became clear that the large majority of genetic optic neuropathies have a primary or an indirect involvement of mitochondrial functions, justifying the definition of "mitochondrial optic neuropathies". Despite this progress many unsolved features remain to be understood, such as incomplete penetrance and variable clinical expressivity in LHON and dominant optic atrophy (DOA), gender prevalence in LHON, and complex gene/environment interactions in both LHON and DOA. The most recent advancement in our understanding of the molecular basis of mitochondrial optic neuropathies is the topic of this review. In particular, we analyze the role that mitochondrial biogenesis may play in the compensatory mechanisms that underlie incomplete penetrance and clinical expressivity, a scenario relevant for the possible design of future therapeutic approaches. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. New technologies for the assessment of neuropathies.

    Science.gov (United States)

    Gasparotti, Roberto; Padua, Luca; Briani, Chiara; Lauria, Giuseppe

    2017-04-01

    Technical advances are rapidly changing the clinical and instrumental approach to peripheral nerve diseases. Magnetic resonance neurography, diffusion tensor imaging and nerve ultrasonography are increasingly entering the diagnostic workup of peripheral neuropathies as tools that complement neurophysiology and enable investigation of proximal structures, such as plexuses and roots. Progress in the design of magnetic resonance scanners and sequences, and the development of high-frequency ultrasound probes mean that high-resolution peripheral nerve imaging is possible, enabling detailed examination of nerve size, morphology and internal fascicular structure that can integrate nerve conduction studies into clinical practice. In the growing field of small-fibre neuropathy, in which traditional nerve conduction studies are of little or no use, skin biopsy has become a reliable tool for diagnosis. Corneal confocal microscopy, nociceptive evoked potentials and microneurography are emerging techniques that are mainly used in clinical research settings, but have increasing relevance to clinical practice. We review these new and emerging techniques and their effects on diagnosis, treatment strategies and prognosis in a variety of peripheral neuropathies, including entrapments, brachial plexopathies, immune and inherited neuropathies, and small-fibre neuropathies. We discuss the most promising research findings and their potential for future application in clinical practice.

  11. Mechanisms of axon degeneration: from development to disease.

    Science.gov (United States)

    Saxena, Smita; Caroni, Pico

    2007-10-01

    Axon degeneration is an active, tightly controlled and versatile process of axon segment self-destruction. Although not involving cell death, it resembles apoptosis in its logics. It involves three distinct steps: induction of competence in specific neurons, triggering of degeneration at defined axon segments of competent neurons, and rapid fragmentation and removal of the segments. The mechanisms that initiate degeneration are specific to individual settings, but the final pathway of pruning is shared; it involves microtubule disassembly, axon swellings, axon fragmentation, and removal of the remnants by locally recruited phagocytes. The tight regulatory properties of axon degeneration distinguish it from passive loss phenomena, and confer significance to processes that involve it. Axon degeneration has prominent roles in development, upon lesions and in disease. In development, it couples the progressive specification of neurons and circuits to the removal of defined axon branches. Competence might involve transcriptional switches, and local triggering can involve axon guidance molecules and synaptic activity patterns. Lesion-induced Wallerian degeneration is inhibited in the presence of Wld(S) fusion protein in neurons; it involves early local, and later, distal degeneration. It has recently become clear that like in other settings, axon degeneration in disease is a rapid and specific process, which should not be confused with a variety of disease-related pathologies. Elucidating the specific mechanisms that initiate axon degeneration should open up new avenues to investigate principles of circuit assembly and plasticity, to uncover mechanisms of disease progression, and to identify ways of protecting synapses and axons in disease.

  12. Morphometry of Axons in Optic Nerves of Siamese's Twins

    Institute of Scientific and Technical Information of China (English)

    Xinzu Gu; Zhenping Zhang; Qi Lin; Jiongji Liang; Wenyu Lu; Xiulan Ye; A A Sadun

    2002-01-01

    Purpose: To observe the development of optic nerve, we examined four optic nerves from Siameses Twins by absolute counts of axons.Methods: Mean axon diameter, mean axon density, totally axonal population and optic nerve area were noted for each optic nerve. The mean axon diameter and the mean axon density were compared between paraxial (inner sectors)and cortical (outer sectors)areas of the nerves.Results: More myelinated axons were seen in the inner sectors as compared to the outer sectors(average 11 axons/1 000 μm2 in inner sectors and 34 axons/l 000 μm2 in outer sectors( P=0. 036) . The myelinated fibers were also smaller(63 microns) in the outer sectors as compared to the inner sectors(72 microns) ( P = 0. 001 ). The average cross sectors area for the four 40 week stage optical nerves of Siamese Twins was 3.32 × 103 as compared to 1 million axons for 32-week-old normals.Conclusion: Our finding of fewer axonal number and small myelinated fibers in the Siamese Twins suggests hypoplasia. Myelination was more abnormal in the paraxial optic nerve than that in the peripheral sectors, suggesting anomalous development of optic nerve peripherally and delayed developnent centrally. Axonal density is higher in inner sectors than that in outer sectors, suggesting delayed development of the outer nerve sector.

  13. In vivo evaluation of a rat model for diabetic neuropathies

    OpenAIRE

    Wauters, Shana

    2007-01-01

    Diabetic peripheral neuropathy is considered to be a long-term complication of Diabetes Mellitus. This neuropathy is the most common form of peripheral neuropathy in the Western world and develops in about 50% of diabetes patients affected with either type I or type II diabetes. Despite advances in understanding metabolic causes of diabetic peripheral neuropathy, specific treatments against this complications are far from being used in therapy options. In this study we have eva...

  14. Autoimmune-mediated peripheral neuropathies and autoimmune pain.

    Science.gov (United States)

    Klein, Christopher J

    2016-01-01

    Peripheral neuropathies have diverse acquired and inherited causes. The autoimmune neuropathies represent an important category where treatment is often available. There are overlapping signs and symptoms between autoimmune neuropathies and other forms. Making a diagnosis can be challenging and first assisted by electrophysiologic and sometimes pathologic sampling, with autoimmune biomarkers providing increased assistance. Here we provide a review of the autoimmune and inflammatory neuropathies, their available biomarkers, and approaches to treatment. Also discussed is new evidence to support a mechanism of autoimmune pain.

  15. Long-term evaluation of Leber's hereditary optic neuropathy-like symptoms in rotenone administered rats.

    Science.gov (United States)

    Zhang, Li; Liu, Laura; Philip, Ann L; Martinez, Juan C; Guttierez, Juan C; Marella, Mathieu; Patki, Gaurav; Matsuno-Yagi, Akemi; Yagi, Takao; Thomas, Biju B

    2015-01-12

    Leber's hereditary optic neuropathy (LHON) is an inherited disorder affecting the retinal ganglion cells (RGCs) and their axons that lead to the loss of central vision. This study is aimed at evaluating the LHON symptoms in rats administered with rotenone microspheres into the superior colliculus (SC). Optical coherence tomography (OCT) analysis showed substantial loss of retinal nerve fiber layer (RNFL) thickness in rotenone injected rats. Optokinetic testing in rotenone treated rats showed decrease in head-tracking response. Electrophysiological mapping of the SC surface demonstrated attenuation of visually evoked responses; however, no changes were observed in the ERG data. The progressive pattern of disease manifestation in rotenone administered rats demonstrated several similarities with human disease symptoms. These rats with LHON-like symptoms can serve as a model for future investigators to design and implement reliable tests to assess the beneficial effects of therapeutic interventions for LHON disease.

  16. Calcium signalling in sensory neurones and peripheral glia in the context of diabetic neuropathies.

    Science.gov (United States)

    Verkhratsky, Alexei; Fernyhough, Paul

    2014-11-01

    Peripheral sensory nervous system is comprised of neurones with their axons and neuroglia that includes satellite glial cells in sensory ganglia, myelinating, non-myelinating and perisynaptic Schwann cells. Pathogenesis of peripheral diabetic polyneuropathies is associated with aberrant function of both neurones and glia. Deregulated Ca(2+) homoeostasis and aberrant Ca(2+) signalling in neuronal and glial elements contributes to many forms of neuropathology and is fundamental to neurodegenerative diseases. In diabetes both neurones and glia experience metabolic stress and mitochondrial dysfunction which lead to deregulation of Ca(2+) homeostasis and Ca(2+) signalling, which in their turn lead to pathological cellular reactions contributing to development of diabetic neuropathies. Molecular cascades responsible for Ca(2+) homeostasis and signalling, therefore, can be regarded as potential therapeutic targets. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Office immunotherapy in chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy.

    Science.gov (United States)

    Dyck, Peter J; Taylor, Bruce V; Davies, Jenny L; Mauermann, Michelle L; Litchy, William J; Klein, Christopher J; Dyck, P James B

    2015-10-01

    Intravenous immunoglobulin [IVIg], plasma exchange [PE], and corticosteroids are efficacious treatment in chronic inflammatory demyelinating polyneuropathy [CIDP]. IVIg is effective in multifocal motor neuropathy [MMN]. NIS, NIS-weakness, sum scores of raw amplitudes of motor fiber (CMAPs) amplitudes, and Dyck/Rankin score provided reliable measures to detect and scale abnormality and reflect change; they are therefore ideal for office management of response-based immunotherapy (R-IRx) of CIDP. Using efficacious R-IRx, a large early and late therapeutic response (≥ one-fourth were in remission or had recovered) was demonstrated in CIDP. In MMN only an early improvement with late non-significant worsening was observed. The difference in immunotherapy response supports a fundamental difference between CIDP (immune attack on Schwann cells and myelin) and MMN (attack on nodes of Ranvier and axons).

  18. Axonal and dendritic changes are associated with diabetic encephalopathy in rats: an important risk factor for Alzheimer's disease.

    Science.gov (United States)

    Zhou, Yanping; Luo, Yi; Dai, Jiapei

    2013-01-01

    Axonopathy is closely linked to and promotes diabetic peripheral neuropathy and a subset of neurological diseases including Alzheimer's disease (AD), but its involvement in the development of diabetic encephalopathy remains unknown. In the present study, we aimed to ascertain the role of axonopathy in the development of diabetic encephalopathy and the possible relationship between diabetic encephalopathy and AD. The streptozotocin (STZ)-induced diabetic rat model was used. A Y-maze task, in vivo neuronal tracing, immunohistochemistry, and western blot analysis were performed to evaluate the cognitive functions, axonal and dendritic changes, and the expressions of amyloid-β (Aβ) and hyperphosphorylated tau in relation to the development of diabetic encephalopathy in this diabetic model. Coincident with significant memory impairment, the diabetic rats showed obvious axonal and dendritic changes, termed axonopathy and dendropathy, respectively, which mainly manifested as the swelling of axons, varicosities, and dendrites in the cognitive-associated brain regions compared to the non-diabetic animals. The site-specific hyperphosphorylated tau, but not deposits of Aβ, was detected in the diabetic rat brains. These data reveal a key role of axonopathy and dendropathy accompanied with the site-specific hyperphosphorylated tau in the course of diabetic encephalopathy, which may be the early link to the neuropathological processes of AD.

  19. Femoral compressive neuropathy from iliopsoas haematoma complicating dengue hemorrhagic fever

    Institute of Scientific and Technical Information of China (English)

    Sneha Ganu; Yesha Mehta

    2013-01-01

    Dengue fever is a debilitating mosquito-borne disease caused by dengue virus. We reported a case of femoral compression neuropathy due to iliopsoas hematoma complicating dengue hemorrhagic fever. Iliopsoas muscle hematoma can cause femoral neuropathy with resultant pain and paralysis. Such manifestations are not well documented in the literature. The pathogenesis of hematoma and compressive neuropathy with its appropriate management is discussed.

  20. MAPK signaling promotes axonal degeneration by speeding the turnover of the axonal maintenance factor NMNAT2

    Science.gov (United States)

    Walker, Lauren J; Summers, Daniel W; Sasaki, Yo; Brace, EJ; Milbrandt, Jeffrey; DiAntonio, Aaron

    2017-01-01

    Injury-induced (Wallerian) axonal degeneration is regulated via the opposing actions of pro-degenerative factors such as SARM1 and a MAPK signal and pro-survival factors, the most important of which is the NAD+ biosynthetic enzyme NMNAT2 that inhibits activation of the SARM1 pathway. Here we investigate the mechanism by which MAPK signaling facilitates axonal degeneration. We show that MAPK signaling promotes the turnover of the axonal survival factor NMNAT2 in cultured mammalian neurons as well as the Drosophila ortholog dNMNAT in motoneurons. The increased levels of NMNAT2 are required for the axonal protection caused by loss of MAPK signaling. Regulation of NMNAT2 by MAPK signaling does not require SARM1, and so cannot be downstream of SARM1. Hence, pro-degenerative MAPK signaling functions upstream of SARM1 by limiting the levels of the essential axonal survival factor NMNAT2 to promote injury-dependent SARM1 activation. These findings are consistent with a linear molecular pathway for the axonal degeneration program. DOI: http://dx.doi.org/10.7554/eLife.22540.001 PMID:28095293

  1. Impairment of retrograde neuronal transport in oxaliplatin-induced neuropathy demonstrated by molecular imaging.

    Directory of Open Access Journals (Sweden)

    Dawid Schellingerhout

    Full Text Available BACKGROUND AND PURPOSE: The purpose of our study was to utilize a molecular imaging technology based on the retrograde axonal transport mechanism (neurography, to determine if oxaliplatin-induced neurotoxicity affects retrograde axonal transport in an animal model. MATERIALS AND METHODS: Mice (n = 8/group were injected with a cumulative dose of 30 mg/kg oxaliplatin (sufficient to induce neurotoxicity or dextrose control injections. Intramuscular injections of Tetanus Toxin C-fragment (TTc labeled with Alexa 790 fluorescent dye were done (15 ug/20 uL in the left calf muscles, and in vivo fluorescent imaging performed (0-60 min at baseline, and then weekly for 5 weeks, followed by 2-weekly imaging out to 9 weeks. Tissues were harvested for immunohistochemical analysis. RESULTS: With sham treatment, TTc transport causes fluorescent signal intensity over the thoracic spine to increase from 0 to 60 minutes after injection. On average, fluorescence signal increased 722%+/-117% (Mean+/-SD from 0 to 60 minutes. Oxaliplatin treated animals had comparable transport at baseline (787%+/-140%, but transport rapidly decreased through the course of the study, falling to 363%+/-88%, 269%+/-96%, 191%+/-58%, 121%+/-39%, 75%+/-21% with each successive week and stabilizing around 57% (+/-15% at 7 weeks. Statistically significant divergence occurred at approximately 3 weeks (p≤0.05, linear mixed-effects regression model. Quantitative immuno-fluorescence histology with a constant cutoff threshold showed reduced TTc in the spinal cord at 7 weeks for treated animals versus controls (5.2 Arbitrary Units +/-0.52 vs 7.1 AU +/-1.38, p0.56, T-test. CONCLUSION: We show-for the first time to our knowledge-that neurographic in vivo molecular imaging can demonstrate imaging changes in a model of oxaliplatin-induced neuropathy. Impaired retrograde neural transport is suggested to be an important part of the pathophysiology of oxaliplatin-induced neuropathy.

  2. AxonQuant: A Microfluidic Chamber Culture-Coupled Algorithm That Allows High-Throughput Quantification of Axonal Damage

    Directory of Open Access Journals (Sweden)

    Yang Li

    2014-02-01

    Full Text Available Published methods for imaging and quantitatively analyzing morphological changes in neuronal axons have serious limitations because of their small sample sizes, and their time-consuming and nonobjective nature. Here we present an improved microfluidic chamber design suitable for fast and high-throughput imaging of neuronal axons. We developed the AxonQuant algorithm, which is suitable for automatic processing of axonal imaging data. This microfluidic chamber-coupled algorithm allows calculation of an ‘axonal continuity index' that quantitatively measures axonal health status in a manner independent of neuronal or axonal density. This method allows quantitative analysis of axonal morphology in an automatic and nonbiased manner. Our method will facilitate large-scale high-throughput screening for genes or therapeutic compounds for neurodegenerative diseases involving axonal damage. When combined with imaging technologies utilizing different gene markers, this method will provide new insights into the mechanistic basis for axon degeneration. Our microfluidic chamber culture-coupled AxonQuant algorithm will be widely useful for studying axonal biology and neurodegenerative disorders. © 2014 S. Karger AG, Basel

  3. Posterior antebrachial cutaneous neuropathy. Case report.

    Science.gov (United States)

    Chang, C W; Oh, S J

    1990-01-01

    Posterior antebrachial cutaneous (PABC) neuropathy is rare. Two original cases are reported here. In case 1, the neuropathy is probably due to a traction injury in a reduction operation for humeral fracture. In case 2, it is injured associately with an operation in taking a myocutaneous flap. On examination, both cases showed a decreased sensation to pin-prick over the PABC nerve territories and a positive Tinel's sign near the injured sites. Sensory nerve conduction study of the PABC nerves revealed a low amplitude of the compound nerve action potential (CNAP) and a slow sensory nerve conduction velocity (SNCV) in case 1, and absent CNAP in case 2. Our study showed the sensory nerve conduction test is useful in confirming PABC neuropathy.

  4. Relief of diabetic neuropathy with fluoxetine.

    Science.gov (United States)

    Theesen, K A; Marsh, W R

    1989-01-01

    A 31-year-old woman with advanced diabetes mellitus with secondary autonomic and peripheral neuropathy was admitted for treatment of major depression. Previous therapy with desipramine resulted in exacerbation of the patient's orthostatic hypotension. After admission to the psychiatric facility she was initially stabilized medically and treated with psychotherapy. Subsequent treatment with low-dose fluoxetine 5 mg resulted in a decrease of the patient's diabetic neuropathy pain. Further increases in the fluoxetine dosage resulted in improvement of her depression and increased pain relief. Therapy with fluoxetine did not result in exacerbation of the orthostatic hypotension. This preliminary case report indicates that fluoxetine may be an alternative to the tricyclic antidepressants and trazodone in the treatment of diabetic peripheral neuropathy.

  5. Phenotyping animal models of diabetic neuropathy

    DEFF Research Database (Denmark)

    Biessels, G J; Bril, V; Calcutt, N A

    2014-01-01

    of statistically different values between diabetic and control animals in 2 of 3 assessments (nocifensive behavior, nerve conduction velocities, or nerve structure). The participants propose that this framework would allow different research groups to compare and share data, with an emphasis on data targeted......NIDDK, JDRF, and the Diabetic Neuropathy Study Group of EASD sponsored a meeting to explore the current status of animal models of diabetic peripheral neuropathy. The goal of the workshop was to develop a set of consensus criteria for the phenotyping of rodent models of diabetic neuropathy....... The discussion was divided into five areas: (1) status of commonly used rodent models of diabetes, (2) nerve structure, (3) electrophysiological assessments of nerve function, (4) behavioral assessments of nerve function, and (5) the role of biomarkers in disease phenotyping. Participants discussed the current...

  6. Anesthesia Management in Diabetic Cardiovascular Autonomic Neuropathy

    Directory of Open Access Journals (Sweden)

    Feride Karacaer

    2016-06-01

    Full Text Available Cardiovascular autonomic neuropathy is frequently observed in patients with diabetes mellitus and encompasses damage to the autonomic nerve fibers, resulting in abnormalities in heart rate control and vascular dynamics. There is an increased mortality and morbidity rate among these patients. A series of cardiovascular reflex tests known as Ewing's battery tests are used for diagnosis cardiac autonomic neuropathy and provide valuable information to the clinical assessment of these patients. As anesthesia has a major influence on perioperative autonomic function, the interplay between cardiovascular autonomic neuropathy and anesthesia may result in unexpected haemodynamic instability during surgery and postoperative recovery. A comprehensive preoperative assessment and perioperative cautious monitoring are necessary for successful anesthesia management. [Archives Medical Review Journal 2016; 25(2.000: 140-151

  7. Infectious optic neuropathies: a clinical update

    Science.gov (United States)

    Kahloun, Rim; Abroug, Nesrine; Ksiaa, Imen; Mahmoud, Anis; Zeghidi, Hatem; Zaouali, Sonia; Khairallah, Moncef

    2015-01-01

    Different forms of optic neuropathy causing visual impairment of varying severity have been reported in association with a wide variety of infectious agents. Proper clinical diagnosis of any of these infectious conditions is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular findings. Diagnosis is confirmed by serologic testing and polymerase chain reaction in selected cases. Treatment of infectious optic neuropathies involves the use of specific anti-infectious drugs and corticosteroids to suppress the associated inflammatory reaction. The visual prognosis is generally good, but persistent severe vision loss with optic atrophy can occur. This review presents optic neuropathies caused by specific viral, bacterial, parasitic, and fungal diseases. PMID:28539795

  8. Treatment of Diabetic Neuropathy- Principles and Methods

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Diabetic neuropathy (DN) is one of the common complications of diabetes mellitus (DM), its incidence can be as high as over 90%. The lesion can involve the sensory, motor and vegetative nerves. As a whole, the lesion can be divided into symmetric multiple neuropathy and asymmetric single neuropathy. Because the pathogenesis of the disease is not clear, no specific therapy is available so far. Besides control of blood sugar level, vitamin B, vasodilators and analgesics are often used in Western medicine for expectant treatment. Basic studies on chronic complications of DM show that aldose reductase and non-enzymatic glycosylation of protein are factors initiating the pathological changes, inhibitors against them have been tested in experimental studies and proved effective. Unfortunately, they are not used clinically due to severe side effects. Screening for herbal drugs to treat DN is still a popular trend in the TCM circle.

  9. Anticeramide antibody and butyrylcholinesterase in peripheral neuropathies.

    Science.gov (United States)

    Sykam, Aparna; Gutlapalli, V R; Tenali, Sandeep P; Meena, A K; Chandran, Priscilla; Suneetha, Sujai; Suneetha, Lavanya M

    2017-08-01

    Ceramide is a glycosphingolipid, a component of nerve and non neuronal cell membrane and plays a role in maintaining the integrity of neuronal tissue. Butyrylcholinesterase (BChE) is a multifunctional enzyme, its involvement in neurodegenerative diseases has been well established. Anticeramide antibody (Ab-Cer) and enzyme BChE have been implicated in peripheral neuropathies. The present study investigates whether there is an association between Ab-Cer and BChE activities and peripheral neuropathies. Patients included: human immunodeficiency virus associated peripheral neuropathy (HIV-PN, n=39), paucibacillary leprosy (PB-L, n=36), multibacillary leprosy (MB-L, n=52), diabetic neuropathy (DN, n=22), demyelinating sensory motor polyneuropathy (DSMN, n=13) and chronic inflammatory demyelinating polyneuropathy (CIDP, n=10). Plasma Ab-Cer was measured by indirect enzyme linked immune assay (ELISA) and BChE activity in plasma was measured by colorimetric method. Ab-Cer levels were significantly elevated in MB-L and DN as compared to healthy subjects (HS). BChE levels were significantly higher in MB-L and DN as well as in HIV and HIV-PN. There is no significant difference in either Ab-Cer or BChE levels in DSMN and CIDP. Elevated plasma Ab-Cer and BChE levels may be considered significant in the pathogenesis of neuropathies. The variation in concurrent involvement of both the molecules in the neuropathies of the study, suggest their unique involvement in neurodegenerative pathways. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. A Major Determinant for Binding and Aminoacylation of tRNAAla in Cytoplasmic Alanyl-tRNA Synthetase Is Mutated in Dominant Axonal Charcot-Marie-Tooth Disease

    OpenAIRE

    Latour, Philippe; Thauvin-Robinet, Christel; Baudelet-Méry, Chantal; Soichot, Pierre; Cusin, Veronica; Faivre, Laurence; Locatelli, Marie-Claire; Mayençon, Martine; Sarcey, Annie; Broussolle, Emmanuel; Camu, William; David, Albert; Rousson, Robert

    2010-01-01

    Charcot-Marie-Tooth disease (CMT) is the most common cause of inherited peripheral neuropathy, with an estimated frequency of 1/2500. We studied a large family with 17 patients affected by the axonal form of CMT (CMT2). Analysis of the 15 genes or loci known to date was negative. Genome-wide genotyping identified a CMT2 locus in 16q21-q23 between D16S3050 and D16S3106. The maximum two-point LOD score was 4.77 at θ = 0 for marker D16S3050. Sequencing of candidate genes identified a unique muta...

  11. [Peripheral neuropathies associated with hereditary cerebellar ataxias].

    Science.gov (United States)

    Anheim, M; Tranchant, C

    2011-01-01

    Inherited cerebellar ataxias constitute a complicated and heterogeneous group of neurodegenerative disorders affecting the cerebellum and/or spinocerebellar tract, spinal cord and peripheral nerves. A peripheral neuropathy is frequently seen in inherited cerebellar ataxias although it rarely reveals the disease. Moreover, the peripheral neuropathy is helpful for the diagnostic procedure and contributes to the functional prognosis of the disease. Thus, electroneuromyography is essential in the algorithm for the diagnosis of inherited cerebellar ataxias, as well as brain MRI (looking especially for cerebellar atrophy) and the assessment of several biomarkers (alpha-foetoprotein, vitamin E, albumin, LDL cholesterol, lactic acid, phytanic acid).

  12. Limb girdle muscular dystrophy due to LAMA2 mutations: diagnostic difficulties due to associated peripheral neuropathy.

    Science.gov (United States)

    Chan, Sophelia H S; Foley, A Reghan; Phadke, Rahul; Mathew, Ann Agnes; Pitt, Matthew; Sewry, Caroline; Muntoni, Francesco

    2014-08-01

    We report an eleven year old girl with early motor difficulties initially diagnosed with a peripheral neuropathy in another hospital based on abnormal electrophysiological findings. Our clinical assessment did not highlight obvious clinical features supporting a peripheral neuropathy but evidence of mild proximal weakness. Electrophysiological studies performed at our hospital revealed evidence of a sensorimotor demyelinating polyneuropathy with possible axonal involvement. Brain magnetic resonance imaging (MRI) revealed subtle white matter signal abnormalities, interpreted as nonspecific. Given the patient's proximal weakness and a mildly elevated serum creatine kinase, we performed a muscle biopsy. The muscle had mildly dystrophic features and subtly depleted laminin α2 expression. There was diffusely upregulated laminin α5 expression, and depletion of laminin α2 in intramuscular motor nerves, which made us suspect a partial laminin α2 (merosin) deficiency. Muscle MRI showed predominant posterior and medial compartments involvement. The patient was found to have autosomal recessively inherited double heterozygous LAMA2 mutations. This case illustrates the mild end of the partial merosin deficiency phenotypic spectrum, and highlights how careful assessment of laminin α2 expression in intramuscular motor nerves can be a helpful diagnostic clue in partial merosin deficiency.

  13. Dynein mutations associated with hereditary motor neuropathies impair mitochondrial morphology and function with age.

    Science.gov (United States)

    Eschbach, Judith; Sinniger, Jérôme; Bouitbir, Jamal; Fergani, Anissa; Schlagowski, Anna-Isabel; Zoll, Joffrey; Geny, Bernard; René, Frédérique; Larmet, Yves; Marion, Vincent; Baloh, Robert H; Harms, Matthew B; Shy, Michael E; Messadeq, Nadia; Weydt, Patrick; Loeffler, Jean-Philippe; Ludolph, Albert C; Dupuis, Luc

    2013-10-01

    Mutations in the DYNC1H1 gene encoding for dynein heavy chain cause two closely related human motor neuropathies, dominant spinal muscular atrophy with lower extremity predominance (SMA-LED) and axonal Charcot-Marie-Tooth (CMT) disease, and lead to sensory neuropathy and striatal atrophy in mutant mice. Dynein is the molecular motor carrying mitochondria retrogradely on microtubules, yet the consequences of dynein mutations on mitochondrial physiology have not been explored. Here, we show that mouse fibroblasts bearing heterozygous or homozygous point mutation in Dync1h1, similar to human mutations, show profoundly abnormal mitochondrial morphology associated with the loss of mitofusin 1. Furthermore, heterozygous Dync1h1 mutant mice display progressive mitochondrial dysfunction in muscle and mitochondria progressively increase in size and invade sarcomeres. As a likely consequence of systemic mitochondrial dysfunction, Dync1h1 mutant mice develop hyperinsulinemia and hyperglycemia and progress to glucose intolerance with age. Similar defects in mitochondrial morphology and mitofusin levels are observed in fibroblasts from patients with SMA-LED. Last, we show that Dync1h1 mutant fibroblasts show impaired perinuclear clustering of mitochondria in response to mitochondrial uncoupling. Our results show that dynein function is required for the maintenance of mitochondrial morphology and function with aging and suggest that mitochondrial dysfunction contributes to dynein-dependent neurological diseases, such as SMA-LED.

  14. Mitochondrial dysfunction in diabetic neuropathy: a series of unfortunate metabolic events.

    Science.gov (United States)

    Fernyhough, Paul

    2015-11-01

    Diabetic neuropathy is a dying back neurodegenerative disease of the peripheral nervous system where mitochondrial dysfunction has been implicated as an etiological factor. Diabetes (type 1 or type 2) invokes an elevation of intracellular glucose concentration simultaneously with impaired growth factor support by insulin, and this dual alteration triggers a maladaptation in metabolism of adult sensory neurons. The energy sensing pathway comprising the AMP-activated protein kinase (AMPK)/sirtuin (SIRT)/peroxisome proliferator-activated receptor-γ coactivator α (PGC-1α) signaling axis is the target of these damaging changes in nutrient levels, e.g., induction of nutrient stress, and loss of insulin-dependent growth factor support and instigates an aberrant metabolic phenotype characterized by a suppression of mitochondrial oxidative phosphorylation and shift to anaerobic glycolysis. There is discussion of how this loss of mitochondrial function and transition to overreliance on glycolysis contributes to the diminishment of collateral sprouting and axon regeneration in diabetic neuropathy in the context of the highly energy-consuming nerve growth cone.

  15. Assessment of diabetic peripheral neuropathy in streptozotocin-induced diabetic rats with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongye; Zhang, Xiang; Lu, Liejing; Li, Haojiang; Zhang, Fang; Chen, Yueyao; Shen, Jun [Sun Yat-Sen University, Department of Radiology, Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong (China)

    2014-09-10

    To determine the role of magnetic resonance (MR) imaging and quantitative T2 value measurements in the assessment of diabetic peripheral neuropathy (DPN). Sequential MR imaging, T2 measurement, and quantitative sensory testing of sciatic nerves were performed in streptozotocin-induced diabetic rats (n = 6) and normal control rats (n = 6) over a 7-week follow-up period. Histological assessment was obtained from 48 diabetic rats and 48 control rats once weekly for 7 weeks (n = 6 for each group at each time point). Nerve signal abnormalities were observed, and the T2 values, mechanical withdrawal threshold (MWT), and histological changes were measured and compared between diabetic and control animals. Sciatic nerves in the diabetic rats showed a gradual increase in T2 values beginning at 2 weeks after the induction (P = 0.014), while a decrease in MWT started at 3 weeks after the induction (P = 0.001). Nerve T2 values had a similar time course to sensory functional deficit in diabetic rats. Histologically, sciatic nerves of diabetic rats demonstrated obvious endoneural oedema from 2 to 3 weeks after the induction, followed by progressive axonal degeneration, Schwann cell proliferation, and coexistent disarranged nerve regeneration. Nerve T2 measurement is potentially useful in detecting and monitoring diabetic neuropathy. (orig.)

  16. Peripheral neuropathy is linked to a severe form of myotonic dystrophy in transgenic mice.

    Science.gov (United States)

    Panaite, Petrica-Adrian; Kielar, Marie; Kraftsik, Rudolf; Gourdon, Geneviève; Kuntzer, Thierry; Barakat-Walter, Ibtissam

    2011-08-01

    Myotonic dystrophy type 1 (DM1) is a multisystem disorder with a variable phenotype. The involvement of peripheral nerves in DM1 disease is controversial. The DM1 animal model DM300 transgenic mice that carry 350 to 500 CTG repeats express a mild DM1 phenotype but do not exhibit motor or sensory pathology. Here, we investigated the presence or absence of peripheral neuropathy in transgenic mice (DMSXL) that carry more than 1,300 CTG repeats and display a severe form of DM1. Electrophysiologic, histologic, and morphometric methods were used to investigate the structure and function of peripheral nerves. We observed lower compound muscle action potentials recorded from hind limb muscles and slowing of sciatic nerve conduction velocity in DMSXL versus control mice. Morphometric analyses showed an axonopathy and neuronopathy in the DMSXL mice characterized by a decrease in numbers of myelinated motor axons in sciatic nerve and in spinal cord motor neurons. Pathologic alterations in the structure of hind limb neuromuscular junctions were also detected in the DMSXL mice. These results suggest that peripheral neuropathy can be linked to a large CTG expansion and a severe form of DM1.

  17. Molecular genetics and mechanisms of disease in distal hereditary motor neuropathies: insights directing future genetic studies.

    Science.gov (United States)

    Drew, A P; Blair, I P; Nicholson, G A

    2011-11-01

    The distal hereditary motor neuropathies (dHMNs) are a clinically and genetically heterogeneous group of disorders that primarily affect motor neurons, without significant sensory involvement. New dHMN genes continue to be identified. There are now 11 causative genes described for dHMN, and an additional five genetic loci with unidentified genes. This genetic heterogeneity has further delineated the classification of dHMN, which was previously classified according to mode of inheritance, age at onset, and additional complicating features. Some overlap between phenotypically distinct forms of dHMN is also apparent. The mutated genes identified to-date in dHMN include HSPB1, HSPB8, HSPB3, DCTN1, GARS, PLEKHG5, BSCL2, SETX, IGHMBP2, ATP7A and TRPV4. The pathogenesis of mutations remains to be fully elucidated, however common pathogenic mechanisms are emerging. These include disruption of axonal transport, RNA processing defects, protein aggregation and inclusion body formation, disrupted calcium channel activity, and loss of neuroprotective signalling. Some of these dHMN genes are also mutated in Charcot-Marie-Tooth (CMT) disease and spinal muscular atrophy (SMA). This review examines the growing number of identified dHMN genes, discusses recent insights into the functions of these genes and possible pathogenic mechanisms, and looks at the increasing overlap between dHMN and the other neuropathies CMT2 and SMA.

  18. The aqueous layers within the myelin sheath modulate the membrane properties of simulated hereditary demyelinating neuropathies.

    Science.gov (United States)

    Stephanova, D I; Krustev, S M; Daskalova, M

    2011-03-01

    To expand our studies on the mechanisms underlying the clinical decline of the nerve excitability properties in patients with hereditary demyelinating neuropathies, the contribution of myelin sheath aqueous layers on multiple membrane properties of simulated fiber demyelinations is investigated. Three progressively greater degrees of internodal systematic demyelinations (two mild and one severe termed as ISD1, ISD2 and ISD3, respectively) without/with aqueous layers are simulated using our previous multi-layered model of human motor nerve fiber. The calculated multiple membrane excitability properties are as follows: potentials (intracellular action, electrotonic), strength-duration time constants, rheobasic currents and recovery cycles. They reflect the propagating, accommodative and adaptive processes in the fibers. The results show that all membrane properties, except for the strength-duration time constants and refractoriness, worsen when the myelin lamellae and their corresponding aqueous layers are uniformly reduced along the fiber length. The effect of the aqueous layers is significantly higher on the accommodative and adaptive processes than on the propagating processes in the fibers. Our multi-layered model better approximated some of the functional deficits documented for axons of patients with Charcot-Marie-Tooth disease type 1A. The study provides new and important information on the mechanisms underlying the pathophysiology of hereditary demyelinating neuropathies.

  19. Two Modes of the Axonal Interferon Response Limit Alphaherpesvirus Neuroinvasion

    Directory of Open Access Journals (Sweden)

    Ren Song

    2016-02-01

    Full Text Available Infection by alphaherpesviruses, including herpes simplex virus (HSV and pseudorabies virus (PRV, typically begins at epithelial surfaces and continues into the peripheral nervous system (PNS. Inflammatory responses are induced at the infected peripheral site prior to invasion of the PNS. When the peripheral tissue is first infected, only the innervating axons are exposed to this inflammatory milieu, which includes the interferons (IFNs. The fundamental question is how do PNS cell bodies respond to these distant, potentially damaging events experienced by axons. Using compartmented cultures that physically separate neuron axons from cell bodies, we found that pretreating isolated axons with beta interferon (IFN-β or gamma interferon (IFN-γ significantly diminished the number of herpes simplex virus 1 (HSV-1 and PRV particles moving in axons toward the cell bodies in a receptor-dependent manner. Exposing axons to IFN-β induced STAT1 phosphorylation (p-STAT1 only in axons, while exposure of axons to IFN-γ induced p-STAT1 accumulation in distant cell body nuclei. Blocking transcription in cell bodies eliminated antiviral effects induced by IFN-γ, but not those induced by IFN-β. Proteomic analysis of IFN-β- or IFN-γ-treated axons identified several differentially regulated proteins. Therefore, unlike treatment with IFN-γ, IFN-β induces a noncanonical, local antiviral response in axons. The activation of a local IFN response in axons represents a new paradigm for cytokine control of neuroinvasion.

  20. Mitochondria Localize to Injured Axons to Support Regeneration.

    Science.gov (United States)

    Han, Sung Min; Baig, Huma S; Hammarlund, Marc

    2016-12-21

    Axon regeneration is essential to restore the nervous system after axon injury. However, the neuronal cell biology that underlies axon regeneration is incompletely understood. Here we use in vivo, single-neuron analysis to investigate the relationship between nerve injury, mitochondrial localization, and axon regeneration. Mitochondria translocate into injured axons so that average mitochondria density increases after injury. Moreover, single-neuron analysis reveals that axons that fail to increase mitochondria have poor regeneration. Experimental alterations to axonal mitochondrial distribution or mitochondrial respiratory chain function result in corresponding changes to regeneration outcomes. Axonal mitochondria are specifically required for growth-cone migration, identifying a key energy challenge for injured neurons. Finally, mitochondrial localization to the axon after injury is regulated in part by dual-leucine zipper kinase 1 (DLK-1), a conserved regulator of axon regeneration. These data identify regulation of axonal mitochondria as a new cell-biological mechanism that helps determine the regenerative response of injured neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Motor and dorsal root ganglion axons serve as choice points for the ipsilateral turning of dI3 axons.

    Science.gov (United States)

    Avraham, Oshri; Hadas, Yoav; Vald, Lilach; Hong, Seulgi; Song, Mi-Ryoung; Klar, Avihu

    2010-11-17

    The axons of the spinal intersegmental interneurons are projected longitudinally along various funiculi arrayed along the dorsal-ventral axis of the spinal cord. The roof plate and the floor plate have a profound role in patterning their initial axonal trajectory. However, other positional cues may guide the final architecture of interneuron tracks in the spinal cord. To gain more insight into the organization of specific axonal tracks in the spinal cord, we focused on the trajectory pattern of a genetically defined neuronal population, dI3 neurons, in the chick spinal cord. Exploitation of newly characterized enhancer elements allowed specific labeling of dI3 neurons and axons. dI3 axons are projected ipsilaterally along two longitudinal fascicules at the ventral lateral funiculus (VLF) and the dorsal funiculus (DF). dI3 axons change their trajectory plane from the transverse to the longitudinal axis at two novel checkpoints. The axons that elongate at the DF turn at the dorsal root entry zone, along the axons of the dorsal root ganglion (DRG) neurons, and the axons that elongate at the VLF turn along the axons of motor neurons. Loss and gain of function of the Lim-HD protein Isl1 demonstrate that Isl1 is not required for dI3 cell fate. However, Isl1 is sufficient to impose ipsilateral turning along the motor axons when expressed ectopically in the commissural dI1 neurons. The axonal patterning of dI3 neurons, revealed in this study, highlights the role of established axonal cues-the DRG and motor axons-as intermediate guidepost cues for dI3 axons.

  2. Axon Membrane Skeleton Structure is Optimized for Coordinated Sodium Propagation

    CERN Document Server

    Zhang, Yihao; Li, He; Tzingounis, Anastasios V; Lykotrafitis, George

    2016-01-01

    Axons transmit action potentials with high fidelity and minimal jitter. This unique capability is likely the result of the spatiotemporal arrangement of sodium channels along the axon. Super-resolution microscopy recently revealed that the axon membrane skeleton is structured as a series of actin rings connected by spectrin filaments that are held under entropic tension. Sodium channels also exhibit a periodic distribution pattern, as they bind to ankyrin G, which associates with spectrin. Here, we elucidate the relationship between the axon membrane skeleton structure and the function of the axon. By combining cytoskeletal dynamics and continuum diffusion modeling, we show that spectrin filaments under tension minimize the thermal fluctuations of sodium channels and prevent overlap of neighboring channel trajectories. Importantly, this axon skeletal arrangement allows for a highly reproducible band-like activation of sodium channels leading to coordinated sodium propagation along the axon.

  3. DIABETIC NEUROPATHY PART 2: PROXIMAL AND ASSYMMETRIC PHENOTYPES

    Science.gov (United States)

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Diabetic neuropathies consist of a variety of syndromes resulting from different types of damage to peripheral or cranial nerves. Although distal symmetric polyneuropathy is most common type of diabetic neuropathy, there are many other subtypes of diabetic neuropathies which have been defined since the 1800’s. Included in these descriptions are patients with proximal diabetic, truncal, cranial, median, and ulnar neuropathies. Various theories have been proposed for the pathogenesis of these neuropathies. The treatment of most of these requires tight and stable glycemic control. Spontaneous recovery is seen in most of these conditions with diabetic control Immunotherapies have been tried in some of these conditions but are quite controversial. PMID:23642718

  4. The electrodiagnostic distinctions between chronic familial and acquired demyelinative neuropathies.

    Science.gov (United States)

    Lewis, R A; Sumner, A J

    1982-06-01

    We compared the electrodiagnostic studies of 40 patients with chronic acquired demyelinative neuropathy and 18 patients with familial demyelinative neuropathy. Patients with acquired neuropathy had differential slowing of conduction velocity when distal latencies were compared with more proximal conduction velocities in the same nerve, when equivalent segments of different nerves were compared, and when dispersion of compound motor action potentials was examined. Conduction block was noted in some patients. Patients with familial disease had uniform conduction slowly of all nerve segments, and conduction block was not seen. Chronic acquired demyelinative neuropathy is characterized by multifocal slowing of nerve conduction, whereas familial demyelinative neuropathy is characterized by uniform conduction slowing.

  5. Plasma dihydroxyphenylglycol (DHPG) as an index of diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Christensen, N J; Dejgaard, Anders; Hilsted, J

    1988-01-01

    Forearm venous plasma noradrenalin and dihydroxyphenylglycol (DHPG) concentrations were measured in eight diabetic patients with and eight diabetic patients without neuropathy. Plasma noradrenalin was on average the same in patients with and without neuropathy and correlated to serum creatinine....... Plasma DHPG concentrations were significantly reduced in patients with autonomic neuropathy as compared to patients without neuropathy (P less than 0.05). A low plasma DHPG/noradrenalin ratio in forearm venous blood identified all patients with autonomic neuropathy except one (P less than 0...

  6. A novel prion disease associated with diarrhea and autonomic neuropathy.

    Science.gov (United States)

    Mead, Simon; Gandhi, Sonia; Beck, Jon; Caine, Diana; Gallujipali, Dillip; Carswell, Christopher; Hyare, Harpreet; Joiner, Susan; Ayling, Hilary; Lashley, Tammaryn; Linehan, Jacqueline M; Al-Doujaily, Huda; Sharps, Bernadette; Revesz, Tamas; Sandberg, Malin K; Reilly, Mary M; Koltzenburg, Martin; Forbes, Alastair; Rudge, Peter; Brandner, Sebastian; Warren, Jason D; Wadsworth, Jonathan D F; Wood, Nicholas W; Holton, Janice L; Collinge, John

    2013-11-14

    Human prion diseases, although variable in clinicopathological phenotype, generally present as neurologic or neuropsychiatric conditions associated with rapid multifocal central nervous system degeneration that is usually dominated by dementia and cerebellar ataxia. Approximately 15% of cases of recognized prion disease are inherited and associated with coding mutations in the gene encoding prion protein (PRNP). The availability of genetic diagnosis has led to a progressive broadening of the recognized spectrum of disease. We used longitudinal clinical assessments over a period of 20 years at one hospital combined with genealogical, neuropsychological, neurophysiological, neuroimaging, pathological, molecular genetic, and biochemical studies, as well as studies of animal transmission, to characterize a novel prion disease in a large British kindred. We studied 6 of 11 affected family members in detail, along with autopsy or biopsy samples obtained from 5 family members. We identified a PRNP Y163X truncation mutation and describe a distinct and consistent phenotype of chronic diarrhea with autonomic failure and a length-dependent axonal, predominantly sensory, peripheral polyneuropathy with an onset in early adulthood. Cognitive decline and seizures occurred when the patients were in their 40s or 50s. The deposition of prion protein amyloid was seen throughout peripheral organs, including the bowel and peripheral nerves. Neuropathological examination during end-stage disease showed the deposition of prion protein in the form of frequent cortical amyloid plaques, cerebral amyloid angiopathy, and tauopathy. A unique pattern of abnormal prion protein fragments was seen in brain tissue. Transmission studies in laboratory mice were negative. Abnormal forms of prion protein that were found in multiple peripheral tissues were associated with diarrhea, autonomic failure, and neuropathy. (Funded by the U.K. Medical Research Council and others.).

  7. Secondary post-geniculate involvement in Leber's hereditary optic neuropathy.

    Directory of Open Access Journals (Sweden)

    Giovanni Rizzo

    Full Text Available Leber's hereditary optic neuropathy (LHON is characterized by retinal ganglion cell (RGC degeneration with the preferential involvement of those forming the papillomacular bundle. The optic nerve is considered the main pathological target for LHON. Our aim was to investigate the possible involvement of the post-geniculate visual pathway in LHON patients. We used diffusion-weighted imaging for in vivo evaluation. Mean diffusivity maps from 22 LHON visually impaired, 11 unaffected LHON mutation carriers and 22 healthy subjects were generated and compared at level of optic radiation (OR. Prefrontal and cerebellar white matter were also analyzed as internal controls. Furthermore, we studied the optic nerve and the lateral geniculate nucleus (LGN in post-mortem specimens obtained from a severe case of LHON compared to an age-matched control. Mean diffusivity values of affected patients were higher than unaffected mutation carriers (P<0.05 and healthy subjects (P<0.01 in OR and not in the other brain regions. Increased OR diffusivity was associated with both disease duration (B = 0.002; P<0.05 and lack of recovery of visual acuity (B = 0.060; P<0.01. Post-mortem investigation detected atrophy (41.9% decrease of neuron soma size in the magnocellular layers and 44.7% decrease in the parvocellular layers and, to a lesser extent, degeneration (28.5% decrease of neuron density in the magnocellular layers and 28.7% decrease in the parvocellular layers in the LHON LGN associated with extremely severe axonal loss (99% in the optic nerve. The post-geniculate involvement in LHON patients is a downstream post-synaptic secondary phenomenon, reflecting de-afferentation rather than a primary neurodegeneration due to mitochondrial dysfunction of LGN neurons.

  8. [Hereditary sensory and motor neuropathy and hereditary sensory and autonomic neuropathies: recent advances].

    Science.gov (United States)

    Stojkovic, T

    2011-12-01

    This review summarizes the recent genetic advances in hereditary sensorimotor neuropathy also called Charcot-Marie-Tooth disease. The different new genes discovered in 2010 and their underlying phenotypes will be presented.

  9. Axon degeneration: make the Schwann cell great again

    Directory of Open Access Journals (Sweden)

    Keit Men Wong

    2017-01-01

    Full Text Available Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration (WD, which occurs after acute axonal injury. In the peripheral nervous system (PNS, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system (CNS, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well-documented that Schwann cells (SCs have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs 'sense' axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro-degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent findings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.

  10. Unusual presentation of hereditary neuropathy with liability to pressure palsies

    Directory of Open Access Journals (Sweden)

    Andary Michael T

    2008-01-01

    Full Text Available Abstract Background Hereditary neuropathy with liability to pressure palsies (HNPP is an autosomal-dominant painless peripheral neuropathy characterized by episodes of repeated focal pressure neuropathies at sites of entrapment/compression, with a considerable variability in the clinical course. Electrodiagnostic and genetic testing are important in the diagnostic evaluation of these patients. Case presentation We report an unusual HNPP phenotype, five compression neuropathies in four nerves in a patient with bilateral hand numbness. A 42-year-old female, presented with acute bilateral paresthesias and weakness in her hands after starting yoga exercises requiring hyperextension of her hands at the wrists. Her presentation was complicated by: a a remote history of acute onset foot drop and subsequent improvement, b previous diagnoses of demyelinating peripheral neuropathy, possibly Charcot-Marie-Tooth disease, and c exposure to leprosy. Electrodiagnostic testing showed 5 separate compression neuropathies in 4 nerves including: severe left and right ulnar neuropathies at the wrist, left and right median neuropathies at the wrist and left ulnar neuropathy at the elbow. There was a mild generalized, primarily demyelinating, peripheral polyneuropathy. Based on the clinical suspicion and electrodiagnostic findings, consistent with profound demyelination in areas of compression, genetic analysis was done which identified a deletion of the PMP-22 gene consistent with HNPP. Conclusion HNPP can present with unusual phenotypes, such as 5 separate mononeuropathies, bilateral ulnar and median neuropathies at the wrists and ulnar neuropathy at the elbow with mild peripheral demyelinating polyneuropathy associated with the PMP-22 gene deletion.

  11. Chemotherapy induced peripheral neuropathy: the modified total neuropathy score in clinical practice.

    OpenAIRE

    Vasquez, S.; Guidon, Marie; McHugh, E; Lennon, Olive; Grogan, L.; Breathnach, O S

    2013-01-01

    BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common, potentially reversible side effect of some chemotherapeutic agents. CIPN is associated with decreased balance, function and quality of life (QoL). This association has to date been under-investigated. AIMS: To profile patients presenting with CIPN using the modified Total Neuropathy Score (mTNS) in this cross-sectional study and to examine the relationship between CIPN (measured by mTNS) and indices of balance, qual...

  12. Schwann cells-axon interaction in myelination.

    Science.gov (United States)

    Taveggia, Carla

    2016-08-01

    The remarkable interaction between glial cells and axons is crucial for nervous system development and homeostasis. Alterations in this continuous communication can cause severe pathologies that can compromise the integrity of the nervous system. The most dramatic consequence of this interaction is the generation of the myelin sheath, made by myelinating glial cells: Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In this review I will focus on signals coming from axons in the first part and then on those from Schwann cells that promote the formation and the maintenance of peripheral myelin. I will discuss their inter-relationship together with seminal and important advances recently made.

  13. Experimental Alcohol-Related Peripheral Neuropathy: Role of Insulin/IGF Resistance

    Directory of Open Access Journals (Sweden)

    James Gilchrist

    2012-08-01

    Full Text Available The mechanisms of alcohol-related peripheral neuropathy (ALPN are poorly understood. We hypothesize that, like alcohol-related liver and brain degeneration, ALPN may be mediated by combined effects of insulin/IGF resistance and oxidative stress. Adult male Long Evans rats were chronically pair-fed with diets containing 0% or 37% ethanol (caloric, and subjected to nerve conduction studies. Chronic ethanol feeding slowed nerve conduction in the tibial (p = 0.0021 motor nerve, and not plantar sensory nerve, but it did not affect amplitude. Histological studies of the sciatic nerve revealed reduced nerve fiber diameters with increased regenerative sprouts, and denervation myopathy in ethanol-fed rats. qRT-PCR analysis demonstrated reduced mRNA levels of insulin, IGF-1, and IGF-2 polypeptides, IGF-1 receptor, and IRS2, and ELISAs revealed reduced immunoreactivity for insulin and IGF-1 receptors, IRS-1, IRS-4, myelin-associated glycoprotein, and tau in sciatic nerves of ethanol-fed rats (all p < 0.05 or better. The findings suggest that ALPN is characterized by (1 slowed conduction velocity with demyelination, and a small component of axonal degeneration; (2 impaired trophic factor signaling due to insulin and IGF resistance; and (3 degeneration of myelin and axonal cytoskeletal proteins. Therefore, ALPN is likely mediated by molecular and signal transduction abnormalities similar to those identified in alcoholic liver and brain degeneration.

  14. Multifunctional Silk Nerve Guides for Axon Outgrowth

    Science.gov (United States)

    Tupaj, Marie C.

    Peripheral nerve regeneration is a critical issue as 2.8% of trauma patients present with this type of injury, estimating a total of 200,000 nerve repair procedures yearly in the United States. While the peripheral nervous system exhibits slow regeneration, at a rate of 0.5 mm -- 9 mm/day following trauma, this regenerative ability is only possible under certain conditions. Clinical repairs have changed slightly in the last 30 years and standard methods of treatment include suturing damaged nerve ends, allografting, and autografting, with the autograft the gold standard of these approaches. Unfortunately, the use of autografts requires a second surgery and there is a shortage of nerves available for grafting. Allografts are a second option however allografts have lower success rates and are accompanied by the need of immunosuppressant drugs. Recently there has been a focus on developing nerve guides as an "off the shelf" approach. Although some natural and synthetic guidance channels have been approved by the FDA, these nerve guides are unfunctionalized and repair only short gaps, less than 3 cm in length. The goal of this project was to identify strategies for functionalizing peripheral nerve conduits for the outgrowth of neuron axons in vitro . To accomplish this, two strategies (bioelectrical and biophysical) were indentified for increasing axon outgrowth and promoting axon guidance. Bioelectrical strategies exploited electrical stimulation for increasing neurite outgrowth. Biophysical strategies tested a range of surface topographies for axon guidance. Novel methods were developed for integrating electrical and biophysical strategies into silk films in 2D. Finally, a functionalized nerve conduit system was developed that integrated all strategies for the purpose of attaching, elongating, and guiding nervous tissue in vitro. Future directions of this work include silk conduit translation into a rat sciatic nerve model in vivo for the purpose of repairing long

  15. Interspecies variation in axon-myelin relationships.

    Science.gov (United States)

    Fraher, J P; O'Sullivan, A W

    2000-01-01

    The primary objective of this paper was to determine the extent and nature of interspecies differences in axon calibre and myelin sheath thickness and in the various relationships between these. Morphometric analysis of the axon perimeter-myelin sheath thickness relationship was performed on an equivalent nerve fibre population in a mammal, the rat, a bird, the chicken, an amphibian, the frog, a bony fish, the trout, and a cartilaginous fish, the dogfish. The abducent nerve was studied. It is especially suitable for this purpose because its fibres are closely similar in type and in peripheral distribution across the species studied. The relationship differed substantially between species. Differences were present in its setting, as described by the positions of the scatterplots, in the g ratio and in the regression and correlation data relating the parameters. Both parameters were markedly larger in the fish species than in all of the others. In addition, in rat, chicken, frog and trout, where large and small fibre classes could be differentiated clearly, the setting of the relationship between the two parameters was different for the two classes. In the main, variation in each of the parameters was greater between than within species. The larger fibres in the fish species were closely similar in axon perimeter and sheath thickness despite their long evolutionary separation. From this study and from others in the series, it may be concluded that there is no fixed or constant relationship between axon calibre and the thickness of the surrounding myelin sheath. Each nerve tends to have its own particular relationship and this differs between species.

  16. Decrease in neuroimmune activation by HSV-mediated gene transfer of TNFα soluble receptor alleviates pain in rats with diabetic neuropathy.

    Science.gov (United States)

    Ortmann, Kathryn L Maier; Chattopadhyay, Munmun

    2014-10-01

    The mechanisms of diabetic painful neuropathy are complicated and comprise of peripheral and central pathophysiological phenomena. A number of proinflammatory cytokines are involved in this process. Tumor necrosis factor α (TNF-α) is considered to be one of the major contributors of neuropathic pain. In order to explore the potential role of inflammation in the peripheral nervous system of Type 1 diabetic animals with painful neuropathy, we investigated whether TNF-α is a key inflammatory mediator to the diabetic neuropathic pain and whether continuous delivery of TNFα soluble receptor from damaged axons achieved by HSV vector mediated transduction of DRG would block or alter the pain perception in animals with diabetic neuropathy. Diabetic animals exhibited changes in threshold of mechanical and thermal pain perception compared to control rats and also demonstrated increases in TNFα in the DRG, spinal cord dorsal horn, sciatic nerve and in the foot skin, 6 weeks after the onset of diabetes. Therapeutic approaches by HSV mediated expression of p55 TNF soluble receptor significantly attenuated the diabetes-induced hyperalgesia and decreased the expression of TNFα with reduction in the phosphorylation of p38MAPK in the spinal cord dorsal horn and DRG. The overall outcome of this study suggests that neuroinflammatory activation in the peripheral nervous system may be involved in the pathogenesis of painful neuropathy in Type 1 diabetes which can be alleviated by local expression of HSV vector expressing p55 TNF soluble receptor.

  17. Retinoic acid signaling in axonal regeneration

    Directory of Open Access Journals (Sweden)

    Radhika ePuttagunta

    2012-01-01

    Full Text Available Following an acute central nervous system injury, axonal regeneration and functional recovery are extremely limited. This is due to an extrinsic inhibitory growth environment and the lack of intrinsic growth competence. Retinoic acid (RA signaling, essential in developmental dorsoventral patterning and specification of spinal motor neurons, has been shown through its receptor, the transcription factor RA receptor β2 (RARß2, to induce axonal regeneration following spinal cord injury (SCI. Recently, it has been shown that in dorsal root ganglia neurons, cAMP levels were greatly increased by lentiviral RARβ2 expression and contributed to neurite outgrowth. Moreover, RARβ agonists, in cerebellar granule neurons and in the brain in vivo, induced phosphoinositide 3-kinase dependent phosphorylation of AKT that was involved in RARβ-dependent neurite outgrowth. More recently, RA-RARß pathways were shown to directly transcriptionally repress a member of the inhibitory Nogo receptor complex, Lingo-1, under an axonal growth inhibitory environment in vitro as well as following spinal injury in vivo. This perspective focuses on these newly discovered molecular mechanisms and future directions in the field.

  18. Shh goes multidirectional in axon guidance

    Institute of Scientific and Technical Information of China (English)

    Paola Bovolenta; Luisa Sanchez-Arrones

    2012-01-01

    Shh and Wnts,secreted by the floor and roof plate of the spinal cord,direct longitudinal growth of the axons from the adjacent ventral funiculus and cortico-spinal tract.Whether these midline cues influencethe directionality of axons elongating in more lateral positions of the spinal cord is unexplored.Song and colleagues investigate this possibility and demonstrate that the location of descending raphe-spinal tract in the ventrolateral spinal cord is dictated by the simultaneous repellent activity of Shh gradients in both the anteriorto-posterior (A-P) and medial-tolateral (M-L) axis. The spinal cord is the main pathway for exchange of information between the brain and the rest of the body.Sensory information collected in the body periphery is conveyed to the brain by axonal tracts that ascend along the spinal cord whereas motor information travels from the brain to the periphery in descending tracts.Precise spatial organization of these fiber tracts is thus essential for animal behavior and survival.

  19. Where does slow axonal transport go?

    Science.gov (United States)

    Terada, Sumio

    2003-12-01

    Axonal transport is the specialized and well-developed intracellular transport system for regulated and/or long-distance transport based on generalized cellular machineries. Among them, slow axonal transport conveys cytoplasmic proteins. The motor molecule, the nature of transporting complex and the transport regulation mechanism for slow transport are still unclarified. There has been a dispute regarding the nature of transporting complex of cytoskeletal proteins, polymer-sliding hypothesis versus subunit-transport theory. Recent data supporting the hypothesis of polymer sliding in cultured neurons only reconfirm the previously reported structure and this inference suffers from the lack of ultrastructural evidence and the direct relevance to the physiological slow transport phenomenon in vivo. Observation of the moving cytoskeletal proteins in vivo using transgenic mice or squid giant axons revealed that subunits do move in a microtubule-dependent manner, strongly indicating the involvement of microtubule-based motor kinesin. If the slow transport rate reflects the intermittent fast transport dependent on kinesin motor, we have to investigate the molecular constituents of the transporting complex in more detail and evaluate why the motor and cargo interaction is so unstable. This kind of weak and fluctuating interaction between various molecular pairs could not be detected by conventional techniques, thus necessitating the establishment of a new experimental system before approaching the molecular regulation problem.

  20. Synaptic Democracy and Vesicular Transport in Axons

    Science.gov (United States)

    Bressloff, Paul C.; Levien, Ethan

    2015-04-01

    Synaptic democracy concerns the general problem of how regions of an axon or dendrite far from the cell body (soma) of a neuron can play an effective role in neuronal function. For example, stimulated synapses far from the soma are unlikely to influence the firing of a neuron unless some sort of active dendritic processing occurs. Analogously, the motor-driven transport of newly synthesized proteins from the soma to presynaptic targets along the axon tends to favor the delivery of resources to proximal synapses. Both of these phenomena reflect fundamental limitations of transport processes based on a localized source. In this Letter, we show that a more democratic distribution of proteins along an axon can be achieved by making the transport process less efficient. This involves two components: bidirectional or "stop-and-go" motor transport (which can be modeled in terms of advection-diffusion), and reversible interactions between motor-cargo complexes and synaptic targets. Both of these features have recently been observed experimentally. Our model suggests that, just as in human societies, there needs to be a balance between "efficiency" and "equality".

  1. Efferent axons in the avian auditory nerve.

    Science.gov (United States)

    Köppl, C

    2001-05-01

    The sensory hair cells of the inner ear receive both afferent and efferent innervation. The efferent supply to the auditory organ has evolved in birds and mammals into a separate complex system, with several types of neurons of largely unknown function. In this study, the efferent axons in four different species of birds (chicken, starling, barn owl and emu) were examined anatomically. Total numbers of efferents supplying the cochlear duct (auditory basilar papilla and the vestibular lagenar macula) were determined; separate estimates of the efferents to the lagenar macula only were also derived and subtracted. The numbers for auditory efferents thus varied between 120 (chicken) and 1068 (barn owl). Considering the much larger numbers of hair cells in the basilar papilla, each efferent is predicted to branch extensively. However, pronounced species-specific differences as well as regional differences along the tonotopic gradient of the basilar papilla were documented. Myelinated and unmyelinated axons were found, with mean diameters of about 1 microm and about 0.5 microm, respectively. This suggests two basic populations of efferents, however, they did not appear to be distinguished sharply. Evidence is presented that some efferents lose their myelination at the transition from central oligodendrocyte to peripheral Schwann cell myelin. Finally, a comparison of the four bird species evaluated suggests that the efferent population with smaller, unmyelinated axons is the phylogenetically more primitive one. A new population probably arose in parallel with the evolution and differentiation of the specialized hair-cell type it innervates, the short hair cell.

  2. MRI of the diffuse axonal injury

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Yang Gu; Woo, Young Hoon; Suh, Soo Jhi [Keimyung University School of Medicine, Daegu (Korea, Republic of)

    1992-01-15

    CT has facilitated early recognition and treatment of focal brain injuries in patients with head trauma. However, CT shows relatively low sensitivity in identifying non hemorrhage contusion and injuries of white matter. MR is known to be superior to CT in detection of white matter injuries, such as diffuse axonal injury. MR imaging in 14 cases of diffuse axonal injury on 2.0T was studied. The corpus callosum, especially the body portion, was the most commonly involved site. The lesions ranged from 5 to 20mm in size with ovoid to elliptical shape. T2WI was the most sensitive pulse sequence in detecting lesions such as white matter degeneration, hemorrhagic and non hemorrhagic contusion. The lesions were nonspecific as high and low signal intensities on T2WI and T1WI respectively. CT showed white matter abnormality in only 1 case of 14 cases. We propose MR imaging as the primary imaging procedure for the detection of diffuse axonal injury because of its multiplanar capabilities and higher sensitivity.

  3. International Neuropathy Workshop of 2009: introduction to the final reports.

    Science.gov (United States)

    Boulton, Andrew J M; Valensi, Paul; Tesfaye, Solomon

    2011-10-01

    Neuropathies are amongst the most common of the long-term complications of diabetes, affecting up to 50% of patients. Their clinical features vary immensely and patients may present with a wide spectrum of specialties, from neurology to urology, for example, or from cardiology to podiatry. Neuropathies are typically characterized by a progressive loss of nerve fibres which may affect both of the principal divisions of the peripheral nervous system. The epidemiology and natural history of the diabetic neuropathies remain poorly defined. The International Consensus Workshop in Toronto in 2009 arose from the fact that at the moment there are no clear, universally accepted guidelines regarding the definition of diabetic neuropathies. This has resulted in a massive variation in how neuropathy is diagnosed in different centres and countries. A preliminary summary report of the Toronto meeting was published in 2010. The series of papers published in this issue of Diabetes/Metabolism Research and Reviews are the detailed reports that came from each sub-group of this Consensus panel. These reviews cover the problems with definitions and classification of neuropathy, the management of painful neuropathy and then the sub-group of small fibre neuropathies. There are also 3 papers on the autonomic neuropathies, covering cardiovascular autonomic neuropathies, as well as other areas of the autonomic neuropathies including gastrointestinal, urogenital and pseudomotor neuropathies. This series of papers will give the reader detailed information on the diverse aspects of diabetic neuropathies, their measurement and management, and will also assist in the selection of appropriate measures of both autonomic and somatic nerve function in clinical trials. This is clearly work in progress as diagnostic criteria for diabetic neuropathies are likely to evolve with developments in the field.

  4. DRP1 inhibition rescues retinal ganglion cells and their axons by preserving mitochondrial integrity in a mouse model of glaucoma.

    Science.gov (United States)

    Kim, K-Y; Perkins, G A; Shim, M S; Bushong, E; Alcasid, N; Ju, S; Ellisman, M H; Weinreb, R N; Ju, W-K

    2015-08-06

    Glaucoma is the leading cause of irreversible blindness and is characterized by slow and progressive degeneration of the optic nerve head axons and retinal ganglion cell (RGC), leading to loss of visual function. Although oxidative stress and/or alteration of mitochondrial (mt) dynamics induced by elevated intraocular pressure (IOP) are associated with this neurodegenerative disease, the mechanisms that regulate mt dysfunction-mediated glaucomatous neurodegeneration are poorly understood. Using a mouse model of glaucoma, DBA/2J (D2), which spontaneously develops elevated IOP, as well as an in vitro RGC culture system, we show here that oxidative stress, as evidenced by increasing superoxide dismutase 2 (SOD2) and mt transcription factor A (Tfam) protein expression, triggers mt fission and loss by increasing dynamin-related protein 1 (DRP1) in the retina of glaucomatous D2 mice as well as in cultured RGCs exposed to elevated hydrostatic pressure in vitro. DRP1 inhibition by overexpressing DRP1 K38A mutant blocks mt fission and triggers a subsequent reduction of oxidative stress, as evidenced by decreasing SOD2 and Tfam protein expression. DRP1 inhibition promotes RGC survival by increasing phosphorylation of Bad at serine 112 in the retina and preserves RGC axons by maintaining mt integrity in the glial lamina of glaucomatous D2 mice. These findings demonstrate an important vicious cycle involved in glaucomatous neurodegeneration that starts with elevated IOP producing oxidative stress; the oxidative stress then leads to mt fission and a specific form of mt dysfunction that generates further oxidative stress, thus perpetuating the cycle. Our findings suggest that DRP1 is a potential therapeutic target for ameliorating oxidative stress-mediated mt fission and dysfunction in RGC and its axons during glaucomatous neurodegeneration. Thus, DRP1 inhibition may provide a new therapeutic strategy for protecting both RGCs and their axons in glaucoma and other optic

  5. Axon-glial relations during regeneration of axons in the adult rat anterior medullary velum.

    Science.gov (United States)

    Berry, M; Hunter, A S; Duncan, A; Lordan, J; Kirvell, S; Tsang, W L; Butt, A M

    1998-12-01

    The anterior medullary velum (AMV) of adult Wistar rats was lesioned in the midsagittal plane, transecting all decussating axons including those of the central projection of the IVth nerve. At selected times up to 200 days after transection, the degenerative and regenerative responses of axons and glia were analyzed using transmission and scanning electron microscopy and immunohistochemistry. In particular, both the capacity of oligodendrocytes to remyelinate regenerated fibers and the stability of the CNS/PNS junctional zone of the IVth nerve rootlet were documented. Transected central AMV axons exhibited four patterns of fiber regeneration in which fibers grew: rostrocaudally in the reactive paralesion neuropil (Group 1); randomly within the AMV (Group 2); into the ipsilateral IVth nerve rootlet, after turning at the lesion edge and growing recurrently through the old degenerated contralateral central trochlear nerve trajectory (Group 3); and ectopically through paralesion tears in the ependyma onto the surface of the IVth ventricle (Group 4). Group 1-3 axons regenerated unperturbed through degenerating central myelin, reactive astrocytes, oligodendrocytes, microglia, and large accumulations of hematogenous macrophages. Only Group 3 axons survived long term in significant numbers, and all became myelinated by oligodendrocytes, ultimately establishing thin sheaths with relatively normal nodal gaps and intersegmental myelin sheath lengths. Schwann cells at the CNS/PNS junction of the IVth nerve rootlet did not invade the CNS, but astrocyte processes grew across the junction into the PNS portion of the IVth nerve. The basal lamina of the junctional glia limitans remained stable throughout the experimental period.

  6. Trigeminal Neuropathy in Sjogren′s Syndrome

    Directory of Open Access Journals (Sweden)

    Pinheiro L

    1999-01-01

    Full Text Available Trigeminal neuropathy is the most common CNS disorder in Sjogren′s syndrome. It is believed to be caused by vasculitis. Unless this is recognised, a diagnosis of trigeminal neuralgia is often made. The therapeutic response to steroids is unpredictable. There are two subgroups - those with associated collagen disorders and those only with the sicca syndrome.

  7. [Sudden blindness: consider Leber's hereditary optic neuropathy

    NARCIS (Netherlands)

    Schieving, J.H.; Vries, L.B.A. de; Hol, F.A.; Stroink, H.

    2008-01-01

    In 3 young male patients, aged 10, 19 and 21 years respectively, sequential, severe, painless bilateral visual loss occurred. Ophthalmological examination revealed no other abnormalities and this delayed the diagnosis Leber's hereditary optic neuropathy (LHON). LHON is a mitochondrial genetic diseas

  8. Glycoconjugates as target antigens in peripheral neuropathies

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    Ljubica Suturkova

    2014-12-01

    Full Text Available Identification and characterization of antigens present at the human peripheral nerve is a great challenge in the field of neuroimmunology. The latest investigations are focused on the understanding of the biology of glycoconjugates present at the peripheral nerve, and their immunological reactivity. Increased titers of antibodies that recognize carbohydrate determinants of glycoconjugates (glycolipids and glycoproteins are associated with distinct neuropathic syndromes. There is considerable cross-reactivity among anti-ganglioside antibodies, resulting from shared oligosaccharide epitopes, possibly explaining the overlap in syndromes observed in many affected patients. Sera from patients with neuropathies (GBS, chronic inflammatory demielynating polyneuropathy - CIDP, multifocal motor neuropathy - MMN, cross-react with glycoproteins isolated from human peripheral nerve and from Campylobacter jejuni O:19. The frequency of occurrence of antibodies against these glycoproteins is different, depending of the type of neuropathy. Identification of the cross-reactive glycoproteins and possible additional auto antigens could be useful in laboratory evaluation of peripheral neuropathies and help to develop a more effective therapeutic approach.

  9. Recurrent peroneal neuropathy in adolescent: clinical case

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    V. A. Bulanova

    2012-01-01

    Full Text Available The clinical case of hereditary neuropathy with liability to pressure palsies (HNPP confirmed the results of DNA diagnostics is described. Clinical and electrophysiological features of the course of HNPP in adolescent is analyzed. Many various illnesses require exclusion in case of the foot extensor paresis.

  10. Recurrent peroneal neuropathy in adolescent: clinical case

    OpenAIRE

    V. A. Bulanova; D. S. Druzhinin

    2012-01-01

    The clinical case of hereditary neuropathy with liability to pressure palsies (HNPP) confirmed the results of DNA diagnostics is described. Clinical and electrophysiological features of the course of HNPP in adolescent is analyzed. Many various illnesses require exclusion in case of the foot extensor paresis.

  11. Autonomic neuropathy and diabetic foot ulceration.

    Science.gov (United States)

    Edmonds, M E; Nicolaides, K H; Watkins, P J

    1986-01-01

    Autonomic function was studied in three groups of insulin-dependent diabetic patients. Heart rate changes during deep breathing and on standing were significantly less in 28 patients with a recent history of foot ulceration compared with 40 patients with peripheral neuropathy but without ulceration (p less than 0.001) and 54 patients without neuropathy (p less than 0.001). Sympathetic function was assessed in 36 of these patients from peripheral arterial diastolic flow patterns obtained by Doppler ultrasound measurements and expressed as the pulsatility index (PI). Patients with a history of ulceration (n = 10) showed considerably increased diastolic flow (PI = 4.28 +/- 0.53, mean +/- S.E.M.) compared with 12 neuropathic patients with no history of ulceration (PI = 7.80 +/- 0.68, p less than 0.002) and 14 patients without neuropathy (PI = 9.55 +/- 0.89, p less than 0.002). Severely abnormal autonomic function occurs in association with neuropathic foot ulceration, but patients without ulcers have lesser degrees of autonomic neuropathy, thus a causal relationship has not been established.

  12. An update on electrophysiological studies in neuropathy

    DEFF Research Database (Denmark)

    Krarup, Christian

    2003-01-01

    The review concentrates on the use of clinical neurophysiology in peripheral nerve disorders covered in the present issue. It is pertinent to distinguish different types of involvement of fibers in diabetic neuropathy, including the involvement of small and large fibers, to outline the diagnostic...

  13. Suboccipital neuropathy after bone conduction device placement

    NARCIS (Netherlands)

    Faber, H.T.; Ru, J.A. de

    2013-01-01

    OBJECTIVE: To describe the clinical characteristics of a 70-year-old female with occipital neuropathy following bone conduction device surgery. DESCRIPTION: A 65-year-old woman underwent bone conduction device placement surgery on the left temporal bone. Postoperatively she progressively developed c

  14. A REVIEW ON DIABETIC NEUROPATHY AND NEPHROPATHY

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    Mohd. Muneer Ahamed

    2012-01-01

    Full Text Available Diabetes is a major public health problem. Diabetes mellitus now affects large number of people in many developing countries than western countries where only two or three percent of the population is affected. With on estimated 33 million people in India alone affected by diabetes. It is a major epidemic of the twentieth century. Diabetes is a chronic disorder, which is associated with obesity, hypertension, advancing age, accumulation of harmful agents in the vascular endothelium causing development of microangiopathies or micro vascular complications. These complications include peripheral neuropathy, nephropathy and retinopathy, which cause early death and increased morbidity. These complications vary in prevalence in different populations depending on various factors such as genetic predisposition and ethnicity. Besides these complications cardiovascular changes are also occurring. Peripheral neuropathy (PN is characterized by pain, numbness, and tingling in the extremities with slow nerve conduction. Up to 50% of all patients with diabetes develop neuropathy and the prevalence of painful neuropathy ranges from 10 to 20% of patients with diabetes. Diabetic nephropathy is characterized by increased urinary protein, loss of renal function, excessive deposition of extracellular matrix proteins in the mesangium, and clear cytoplasm of the proximal tubular epithelial cells due to excessive reabsorbed glycogen. Evaluation of diabetes and its complications is very essential for proper control and prevention of the disease associated complications.

  15. Pediatric enteric neuropathies: diagnosis and current management.

    Science.gov (United States)

    Westfal, Maggie L; Goldstein, Allan M

    2017-06-01

    Neurointestinal diseases are increasingly recognized as causes of significant gastrointestinal morbidity in children. This review highlights the most common pediatric enteric neuropathies and their diagnosis and management, emphasizing insights and discoveries from the most recent literature available. The embryologic and histopathologic causes of enteric neuropathies are varied. They range from congenital aganglionosis in Hirschsprung disease, to autoimmune-mediated loss of neuronal subtypes in esophageal achalasia and Chagas disease, to degenerative neuropathies in some cases of chronic intestinal pseudo-obstruction and gastroparesis. Increased awareness of the clinical presentation and diagnostic evaluation of these conditions is essential as it allows for earlier initiation of treatment and improved outcomes. Most current therapies, which include medical management, neurostimulation, and operative intervention, aim to minimize the symptoms caused by these conditions. The evidence base for many of these treatments in children is poor, and multiinstitutional prospective studies are needed. An innovative therapy on the horizon involves using neuronal stem cell transplantation to treat the underlying disorder by replacing the missing or damaged neurons in these diseases. Although recent advances in basic and clinical neurogastroenterology have significantly improved our awareness and understanding of enteric neuropathies, the efficacy of current treatment approaches is limited. The development of novel therapies, including pharmacologic modulators of neurointestinal function, neurostimulation to enhance gut motility, and neuronal cell-based therapies, is essential to improve the long-term outcomes in children with these disorders.

  16. Idiopathic trigeminal neuropathy in a poodle

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    Carlos Eduardo Aparicio

    2010-12-01

    Full Text Available A seven years old, male poodle is examined presenting acute mandible paralysis (dropped jaw, drooling and difficulty for the apprehension and chewing; not evidence of an other alteration of cranial nerves. The muscular biopsy rules out a myositisof masticatory muscles. The disorder is resolved completely in 3 weeks confirming diagnosis of idiopathic trigeminal neuropathy.

  17. Ciliary neurotrophic factor activates NF-κB to enhance mitochondrial bioenergetics and prevent neuropathy in sensory neurons of streptozotocin-induced diabetic rodents.

    Science.gov (United States)

    Saleh, Ali; Roy Chowdhury, Subir K; Smith, Darrell R; Balakrishnan, Savitha; Tessler, Lori; Martens, Corina; Morrow, Dwane; Schartner, Emily; Frizzi, Katie E; Calcutt, Nigel A; Fernyhough, Paul

    2013-02-01

    Diabetes causes mitochondrial dysfunction in sensory neurons that may contribute to peripheral neuropathy. Ciliary neurotrophic factor (CNTF) promotes sensory neuron survival and axon regeneration and prevents axonal dwindling, nerve conduction deficits and thermal hypoalgesia in diabetic rats. In this study, we tested the hypothesis that CNTF protects sensory neuron function during diabetes through normalization of impaired mitochondrial bioenergetics. In addition, we investigated whether the NF-κB signal transduction pathway was mobilized by CNTF. Neurite outgrowth of sensory neurons derived from streptozotocin (STZ)-induced diabetic rats was reduced compared to neurons from control rats and exposure to CNTF for 24 h enhanced neurite outgrowth. CNTF also activated NF-κB, as assessed by Western blotting for the NF-κB p50 subunit and reporter assays for NF-κB promoter activity. Conversely, blockade of NF-κB signaling using SN50 peptide inhibited CNTF-mediated neurite outgrowth. Studies in mice with STZ-induced diabetes demonstrated that systemic therapy with CNTF prevented functional indices of peripheral neuropathy along with deficiencies in dorsal root ganglion (DRG) NF-κB p50 expression and DNA binding activity. DRG neurons derived from STZ-diabetic mice also exhibited deficiencies in maximal oxygen consumption rate and associated spare respiratory capacity that were corrected by exposure to CNTF for 24 h in an NF-κB-dependent manner. We propose that the ability of CNTF to enhance axon regeneration and protect peripheral nerve from structural and functional indices of diabetic peripheral neuropathy is associated with targeting of mitochondrial function, in part via NF-κB activation, and improvement of cellular bioenergetics.

  18. Clinical and cytogenetic study of a case with familial chromosomal translocation presenting with facial dysmorphism and axial neuropathy.

    Science.gov (United States)

    El-Bassyouni, H T; Shehab, M; Kora, H M; Temtamy, S A

    2012-01-01

    We report on a 9-year-old female patient presenting with muscle weakness, facial dysmorphism and mild mental retardation. She had low birth weight, developmental delay, hypotonia and hyporeflexia and difficulties in climbing the stairs. EMG revealed axonal polyneuropathy affecting both upper and lower limbs. She was the child of non-consanguineous parents, her cytogenetic findings revealed 46,XX,t(12;14)(q14;q23). The mother's karyotype was normal 46,XX while the father's karyotype was 46,XY,t(12;14)(q14;q23) the same as his daughter. Her normal sister's karyotype was also 46,XX,t(12; 14) (q14;q23). Fluorescence in situ hybridization (FISH) was used to elucidate the breakpoints and Array-CGH was done for the patient to confirm the balanced translocation. This observation is of interest because it represents a rare case of a balanced translocation with abnormal phenotype. Mutant genes causing axonal neuropathy have been located on various chromosomes other than 12q14 or 14q24. This report shows the importance of molecular cytogenetics and its correlation with abnormal phenotype and the possibility of another gene locus at the presently studied chromosomal breakpoints. Detailed correlations between chromosome aberrations and their phenotypes are of invaluable help in localising genes for axonal polyneuropathy.

  19. Correlation between PMP-22 messenger RNA expression and phenotype in hereditary neuropathy with liability to pressure palsies.

    Science.gov (United States)

    Schenone, A; Nobbio, L; Caponnetto, C; Abbruzzese, M; Mandich, P; Bellone, E; Ajmar, F; Gherardi, G; Windebank, A J; Mancardi, G

    1997-12-01

    Hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a deletion in chromosome 17p11.2, which includes the gene for the peripheral myelin protein 22 (PMP-22). A "gene dosage" effect is probably the mechanism underlying HNPP, but the amount of PMP-22 mRNA in sural nerves of HNPP patients is highly variable and the role of PMP-22 underexpression in impairing myelination has yet to be clarified. We have studied 6 genetically proven HNPP patients, to evaluate the relationship between PMP-22 mRNA levels, and clinical, neurophysiological, and neuropathological findings. Underexpression of PMP-22 mRNA correlates with disease severity and with mean axon diameter and g ratio, but not with myelin thickness, number of "tomacula," or nerve conduction parameters. Our findings further confirm that underexpression of PMP-22 is the main pathogenetic mechanism underlying the severity of clinical symptoms and signs in HNPP. Smaller axons in sural nerves of HNPP patients with lower PMP-22 levels suggests that underexpression of PMP-22 may also affect axon development.

  20. Erythropoietin enhances nerve repair in anti-ganglioside antibody-mediated models of immune neuropathy.

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    Full Text Available Guillain-Barré syndrome (GBS is a monophasic immune neuropathic disorder in which a significant proportion of patients have incomplete recovery. The patients with incomplete recovery almost always have some degree of failure of axon regeneration and target reinnervation. Anti-ganglioside antibodies (Abs are the most commonly recognized autoimmune markers in all forms of GBS and specific Abs are associated with the slow/poor recovery. We recently demonstrated that specific anti-ganglioside Abs inhibit axonal regeneration and nerve repair in preclinical models by activation of small GTPase RhoA and its downstream effectors. The objective of this study was to determine whether erythropoietin (EPO, a pleiotropic cytokine with neuroprotective and neurotrophic properties, enhances nerve regeneration in preclinical cell culture and animal models of autoimmune neuropathy/nerve repair generated with monoclonal and patient derived Abs. Primary neuronal cultures and a standardized sciatic crush nerve model were used to assess the efficacy of EPO in reversing inhibitory effects of anti-ganglioside Abs on nerve repair. We found that EPO completely reversed the inhibitory effects of anti-ganglioside Abs on axon regeneration in cell culture models and significantly improved nerve regeneration/repair in an animal model. Moreover, EPO-induced proregenerative effects in nerve cells are through EPO receptors and Janus kinase 2/Signal transducer and activator of transcription 5 pathway and not via early direct modulation of small GTPase RhoA. These preclinical studies indicate that EPO is a viable candidate drug to develop further for neuroprotection and enhancing nerve repair in patients with GBS.