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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. Genetics Home Reference: giant axonal neuropathy

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    ... in giant axonal neuropathy: new insights into disease mechanisms. Muscle Nerve. 2012 Aug;46(2):246-56. ... with a qualified healthcare professional . About Genetics Home Reference Site Map Contact Us Selection Criteria for Links ...

  3. Axonal loss and neuroprotection in optic neuropathies.

    Science.gov (United States)

    Levin, Leonard A

    2007-06-01

    Most optic neuropathies do not have effective treatments. Examples are ischemic optic neuropathy, Leber hereditary optic neuropathy, optic neuritis, and traumatic optic neuropathy. In some cases, the pathophysiology of the optic nerve injury is not fully understood. For example, while the demyelinative aspects of optic neuritis have been studied, the mechanism by which the axonal loss occurs is less apparent. In other cases, although the pathophysiology of the optic neuropathy may be understood, there is difficulty treating the disease, for example, with traumatic optic neuropathy. In response to this therapeutic dearth, the concept of neuroprotection has arisen. Neuroprotection is a therapeutic paradigm for preventing death of neurons from injury and maintaining function. In optic neuropathies, the corresponding neuron is the retinal ganglion cell. These cells are unable to divide, and optic neuropathies irrevocably result in their death; therefore, the primary target of neuroprotection are retinal ganglion cells and their axons. This review emphasizes that most optic neuropathies are axonal and thus good targets for neuroprotection. PMID:17508035

  4. Axonal neuropathy associated with monoclonal gammopathy of undetermined significance

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    GORSON, K.; Ropper, A.

    1997-01-01

    OBJECTIVE—The neuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) is typically a predominantly demyelinating process that may have additional features of axonal degeneration. Sixteen patients with MGUS and a pure or predominantly axonal neuropathy are reported and compared with 20 consecutive patients with demyelinating neuropathy and MGUS who were seen during the same period.
METHODS—Retrospective review of a consecutive series of patients w...

  5. 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.

  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. Axonal Transport Impairment in Chemotherapy-Induced Peripheral Neuropathy

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    Gabriella Nicolini

    2015-08-01

    Full Text Available Chemotherapy-Induced Peripheral Neuropathy (CIPN is a dose-limiting side effect of several antineoplastic drugs which significantly reduces patients’ quality of life. Although different molecular mechanisms have been investigated, CIPN pathobiology has not been clarified yet. It has largely been recognized that Dorsal Root Ganglia are the main targets of chemotherapy and that the longest nerves are the most damaged, together with fast axonal transport. Indeed, this bidirectional cargo-specific transport has a pivotal role in neuronal function and its impairment is involved in several neurodegenerative and neurodevelopmental diseases. Literature data demonstrate that, despite different mechanisms of action, all antineoplastic agents impair the axonal trafficking to some extent and the severity of the neuropathy correlates with the degree of damage on this bidirectional transport. In this paper, we will examine the effect of the main old and new chemotherapeutic drug categories on axonal transport, with the aim of clarifying their potential mechanisms of action, and, if possible, of identifying neuroprotective strategies, based on the knowledge of the alterations induced by each drugs.

  8. Axon Transport and Neuropathy: Relevant Perspectives on the Etiopathogenesis of Familial Dysautonomia.

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    Tourtellotte, Warren G

    2016-03-01

    Peripheral neuropathies are highly prevalent and are most often associated with chronic disease, side effects from chemotherapy, or toxic-metabolic abnormalities. Neuropathies are less commonly caused by genetic mutations, but studies of the normal function of mutated proteins have identified particular vulnerabilities that often implicate mitochondrial dynamics and axon transport mechanisms. Hereditary sensory and autonomic neuropathies are a group of phenotypically related diseases caused by monogenic mutations that primarily affect sympathetic and sensory neurons. Here, I review evidence to indicate that many genetic neuropathies are caused by abnormalities in axon transport. Moreover, in hereditary sensory and autonomic neuropathies. There may be specific convergence on gene mutations that disrupt nerve growth factor signaling, upon which sympathetic and sensory neurons critically depend. PMID:26724390

  9. Burning feet in polycythemia vera – peripheral sensorimotor axonal neuropathy with erythromelalgia

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    Wollina U

    2015-02-01

    Full Text Available Uwe Wollina Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Dresden, Germany Abstract: Polycythemia vera is a rare myeloproliferative disease. Cutaneous symptoms are uncommon. We report about a 72-year-old female patient with JAK2V617F-positive polycythemia who developed peripheral sensorimotor axonal neuropathy and erythromelalgia. Possible causes and treatment are discussed. Keywords: bone marrow diseases, myeloproliferative diseases, JAK2 mutations, burning sensations, peripheral neuropathy

  10. Sympathetic skin response--a method of assessing unmyelinated axon dysfunction in peripheral neuropathies.

    OpenAIRE

    Shahani, B T; Halperin, J J; Boulu, P; Cohen, J.

    1984-01-01

    The sympathetic skin response (SSR) was measured in 33 patients with peripheral neuropathies and in 30 normal control subjects. Abnormalities of the response were correlated with clinical, pathologic, and EMG observations. The response was usually absent in axonal neuropathies, but present in demyelinating disorders. Abnormalities of the sympathetic skin response did not correlate well with clinical evidence of dysautonomia, but were a reliable indicator of disorders affecting unmyelinated ax...

  11. Clinical features and molecular modelling of novel MPZ mutations in demyelinating and axonal neuropathies

    OpenAIRE

    Mandich, Paola; Fossa, Paola; Capponi, Simona; Geroldi, Alessandro; Acquaviva, Massimo; Gulli, Rossella; Ciotti, Paola; MANGANELLI, FIORE; Grandis, Marina; Bellone, Emilia

    2009-01-01

    Mutations in the myelin protein zero (MPZ) gene have been associated with different Charcot–Marie–Tooth disease (CMT) phenotypes, including classical demyelinating CMT1B and the axonal form of the disease (CMT2). The MPZ role in the pathogenesis of both demyelinating and axonal inherited neuropathies was evaluated in the Italian population by screening a cohort of 214 patients with CMT1 or CMT2. A MPZ mutation frequency of 7.9% in demyelinating cases and of 4.8% in axonal cases was observed. ...

  12. Application of autologous bone marrow stem cells in giant axonal neuropathy

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    Alok Sharma

    2010-01-01

    Full Text Available Giant axonal neuropathy is a rare disorder of autosomal recessive inheritance, morphologically characterized by accumulation of neurofilaments in enlargements of preterminal regions of central and peripheral axons. We present a 7-year-old girl with thick and tightly curled lackluster hair suffering from giant axonal neuropathy. The diagnosis was confirmed on the brain MRI which showed white matter abnormalities in the anterior and posterior periventricular regions as well as the cerebellar white matter. In view of the same, the patient was given intrathecal autologous bone marrow-derived stem cell therapy as part of the neuroregenerative rehabilitation therapy protocol. The patient showed functional improvements in her disability after receiving the therapy. A detailed case report is presented here with.

  13. gamma-Diketone neuropathy: axon atrophy and the role of cytoskeletal protein adduction.

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    LoPachin, Richard M; DeCaprio, Anthony P

    2004-08-15

    Multifocal giant neurofilamentous axonal swellings and secondary distal degeneration have been historically considered the hallmark features of gamma-diketone neuropathy. Accordingly, research conducted over the past 25 years has been directed toward discerning mechanisms of axonal swelling. However, this neuropathological convention has been challenged by recent observations that swollen axons were an exclusive product of long-term 2.5-hexanedione (HD) intoxication at lower daily dose-rates (e.g., 175 mg/kg/day); that is, higher HD dose-rates (e.g., 400 mg/kg/day) produced neurological deficits in the absence of axonal swellings. The observation that neurological toxicity can be expressed without axonal swelling suggests that this lesion is not an important pathophysiological event. Instead, several research groups have now shown that axon atrophy is prevalent in nervous tissues of laboratory animals intoxicated over a wide range of HD dose-rates. The well-documented nerve conduction defects associated with axon atrophy, in conjunction with the temporal correspondence between this lesion and the onset of neurological deficits, strongly suggest that atrophy has pathophysiological significance. In this commentary, we present evidence that supports a pathognomonic role for axon atrophy in gamma-diketone neuropathy and suggests that the functional consequences of this lesion mediate the corresponding neurological toxicity. Previous research has demonstrated that HD interacts with proteins via formation of pyrrole adducts. We therefore discuss the possibility that this chemical process is essential to the mechanism of atrophy. Evidence presented in this review suggests that "distal axonopathy" is an inaccurate classification and future nosological schemes should be based on the apparent primacy of axon atrophy. PMID:15289087

  14. 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.

  15. Organophosphates induce distal axonal damage, but not brain oedema, by inactivating neuropathy target esterase

    International Nuclear Information System (INIS)

    Single doses of organophosphorus compounds (OP) which covalently inhibit neuropathy target esterase (NTE) can induce lower-limb paralysis and distal damage in long nerve axons. Clinical signs of neuropathy are evident 3 weeks post-OP dose in humans, cats and chickens. By contrast, clinical neuropathy in mice following acute dosing with OPs or any other toxic compound has never been reported. Moreover, dosing mice with ethyloctylphosphonofluoridate (EOPF) - an extremely potent NTE inhibitor - causes a different (subacute) neurotoxicity with brain oedema. These observations have raised the possibility that mice are intrinsically resistant to neuropathies induced by acute toxic insult, but may incur brain oedema, rather than distal axonal damage, when NTE is inactivated. Here we provide the first report that hind-limb dysfunction and extensive axonal damage can occur in mice 3 weeks after acute dosing with a toxic compound, bromophenylacetylurea. Three weeks after acutely dosing mice with neuropathic OPs no clinical signs were observed, but distal lesions were present in the longest spinal sensory axons. Similar lesions were evident in undosed nestin-cre:NTEfl/fl mice in which NTE had been genetically-deleted from neural tissue. The extent of OP-induced axonal damage in mice was related to the duration of NTE inactivation and, as reported in chickens, was promoted by post-dosing with phenylmethanesulfonylfluoride. However, phenyldipentylphosphinate, another promoting compound in chickens, itself induced in mice lesions different from the neuropathic OP type. Finally, EOPF induced subacute neurotoxicity with brain oedema in both wild-type and nestin-cre:NTEfl/fl mice indicating that the molecular target for this effect is not neural NTE.

  16. Burning feet in polycythemia vera – peripheral sensorimotor axonal neuropathy with erythromelalgia

    OpenAIRE

    Wollina U

    2015-01-01

    Uwe Wollina Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Dresden, Germany Abstract: Polycythemia vera is a rare myeloproliferative disease. Cutaneous symptoms are uncommon. We report about a 72-year-old female patient with JAK2V617F-positive polycythemia who developed peripheral sensorimotor axonal neuropathy and erythromelalgia. Possible causes and treatment are discussed. Keywords: bone marrow diseases, myeloproliferative diseases, JAK2 mut...

  17. Giant axonal neuropathy-like disease in an Alexandrine parrot (Psittacula eupatria).

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    Stent, Andrew; Gosbell, Matthew; Tatarczuch, Liliana; Summers, Brian A

    2015-09-01

    A chronic progressive neurological condition in an Alexandrine parrot (Psittacula eupatria) was manifest as intention tremors, incoordination, and seizure activity. Histology revealed large eosinophilic bodies throughout the central nervous system, and electron microscopy demonstrated that these bodies were greatly expanded axons distended by short filamentous structures that aggregated to form long strands. The presence of periodic acid-Schiff-positive material within the neuronal bodies of Purkinje cells and ganglionic neurons is another distinctive feature of this disease. The histological features of this case display some features consistent with giant axonal neuropathy as reported in humans and dogs. Based on investigation of the lineage in this case, an underlying inherited defect is suspected, but some additional factor appears to have altered the specific disease presentation in this bird. PMID:26330398

  18. 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.

  19. Sensomotor axonal peripheral neuropathy as a first complication of polycythemia rubra vera: A report of 3 cases

    OpenAIRE

    Mihalj, Mario; Titlić, Marina; BONACIN, DAMIR; Đogaš, Zoran

    2013-01-01

    Patient: Female, 64 Final Diagnosis: Polycythemia rubra vera Symptoms: Burning pain • cramps • hypesthesia • itching • paresthesia Medication: — Clinical Procedure: — Specialty: Neurology Objective: Unusual clinical course Background: The association between polycythemia vera and peripheral neuropathy has been described previously but only as a late complication and only with sensory axonal polyneuropathy. We presume the cause of polyneuropathy was hypoxia due to higher blood viscosity and dy...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. A review of gigaxonin mutations in giant axonal neuropathy (GAN) and cancer.

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    Kang, James J; Liu, Isabelle Y; Wang, Marilene B; Srivatsan, Eri S

    2016-07-01

    Gigaxonin, the product of GAN gene localized to chromosome 16, is associated with the early onset neuronal degeneration disease giant axonal neuropathy (GAN). Gigaxonin is an E3 ubiquitin ligase adaptor protein involved in intermediate filament processing in neural cells, and vimentin filaments in fibroblasts. Mutations of the gene cause pre-neural filaments to accumulate and form giant axons resulting in the inhibition of neural cell signaling. Analysis of the catalog of somatic mutations in cancer, driver DB and IDGC data portal databases containing 21,000 tumor genomic sequences has identified GAN patient mutations in cancer cell lines and primary tumors. The database search has also shown the presence of identical missense and nonsense gigaxonin mutations in GAN and colon cancer. These mutations frequently occur in the domains associated with protein homodimerization and substrate interaction such as Broad-Complex, Tramtrack and Bric a brac (BTB), BTB associated C-terminal KELCH (BACK), and KELCH repeats. Analysis of the International HapMap Project database containing 1200 normal genomic sequences has identified a single nucleotide polymorphism (SNP), rs2608555, in exon 8 of the gigaxonin sequence. While this SNP is present in >40 % of Caucasian population, it is present in less than 10 % of Japanese and Chinese populations. Although the role of gigaxonin polymorphism is not yet known, CFTR and MDR1 gene studies have shown that silent mutations play a role in the instability and aberrant splicing and folding of mRNAs. We believe that molecular and functional investigation of gigaxonin mutations including the exon 8 polymorphism could lead to an improved understanding of the relationship between GAN and cancer.

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

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    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

  3. 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 areflexia were found in neurological examination. There were motor conduction blocks in all peripheral nerves in electrophysiological studies.According to these findings the patient was diagnosed as Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP). Reduction of CMAP amplitudes in posterior tibial nerve, absence of CMAPs in median, ulnar and peroneal nerves and loss of motor conduction blocks were found in following electrophysiological studies. According to these findings, patient was diagnosed as AMAN. Motor conduction blocks may appear in early stage of AMAN and they disappear in later examinations. That's why electrophysiological studies must be repeated in patients with GBS. PMID:27057191

  4. Gamma-Diketone central neuropathy: quantitative analyses of cytoskeletal components in myelinated axons of the rat rubrospinal tract.

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    Lopachin, Richard M; Jortner, Bernard S; Reid, Maria L; Monir, Alim

    2005-12-01

    Loss of axon caliber is a primary component of gamma-diketone neuropathy [LoPachin RM, DeCaprio AP. gamma-Diketone central neuropathy: axon atrophy and the role of cytoskeletal protein adduction. Toxicol Appl Pharmacol 2004;199:20-34]. It is possible that this effect is mediated by changes in the density of cytoskeletal components and corresponding spatial relationships. To examine this possibility, morphometric methods were used to quantify the effects of 2,5-hexanedione (HD) intoxication on neurofilament-microtubule densities and nearest neighbor distances in myelinated rubrospinal axons. Rats were exposed to HD at one of two daily dose-rates (175 or 400 mg/kg per day, gavage) until a moderate level of neurotoxicity was achieved (99 or 21 days of intoxication, respectively) as determined by gait analysis and measurements of hindlimb grip strength. Results indicate that, regardless of dose-rate, HD intoxication did not cause changes in axonal neurofilament (NF) density, but did significantly increase microtubule (MT) density. No consistent alterations in interneurofilament or NF-MT distances were detected by ultrastructural morphometric analyses. These data suggest that the axon atrophy induced by HD was not mediated by major disruptions of stationary cytoskeletal organization. Recent biochemical studies of spinal cord from HD intoxicated rats showed that, although the NF protein content in the stationary cytoskeleton (polymer fraction) was not affected, the mobile subunit pool was depleted substantially [LoPachin RM, He D, Reid ML, Opanashuk LA. 2,5-Hexanedione-induced changes in the monomeric neurofilament protein content of rat spinal cord fractions. Toxicol Appl Pharmacol 2004;198:61-73]. The stability of the polymer fraction during HD intoxication is consistent with the absence of significant ultrastructural modifications noted in the present study. Together, these findings implicate loss of mobile NF proteins as the primary mechanism of axon atrophy. PMID

  5. The neuropathic oesophagus. A radiographic and manometric study on the evolution of megaoesophagus in dogs with developing axonal neuropathy

    International Nuclear Information System (INIS)

    Dogs given the neurotoxin acrylamide develop peripheral neuropathy and megaoesophagus. Sequential radiographic and manometric studies on the oesophagus demonstrated that the initial abnormalities consisted of a progressive decrease in the proportion of swallows that initiated peristalsis and a gradual increase in oesophageal calibre. Regurgitation, peristaltic failure and oesophageal dilatation all appeared within three days. The eating behaviour and gait abnormalities quickly resolved on stopping the neurotoxin, but the oesophagus remained dilated for longer. Previous studies have suggested that the abnormalities present in dogs which are developing a distal axonal neuropathy or in some dogs with idiopathic megaoesophagus may be limited to the proprioceptive elements of the oesophageal innervation. The present study suggests that the progressive inefficiency in the transmission of swallows and changes in oesophageal calibre in dogs with evolving megaoesophagus may be a consequence of damage to these proprioceptive elements

  6. The instability of the BTB-KELCH protein Gigaxonin causes Giant Axonal Neuropathy and constitutes a new penetrant and specific diagnostic test

    OpenAIRE

    Boizot, Alexia; Talmat-Amar, Yasmina; Morrogh, Deborah; Kuntz, Nancy; Halbert, Cecile; Chabrol, Brigitte; Houlden, Henry; Stojkovic, Tanya; Schulman, Brenda; Rautenstrauss, Bernd; Bomont, Pascale

    2014-01-01

    International audience BACKGROUND: The BTB-KELCH protein Gigaxonin plays key roles in sustaining neuron survival and cytoskeleton architecture. Indeed, recessive mutations in the Gigaxonin-encoding gene cause Giant Axonal Neuropathy (GAN), a severe neurodegenerative disorder characterized by a wide disorganization of the Intermediate Filament network. Growing evidences suggest that GAN is a continuum with the peripheral neuropathy Charcot-Marie-Tooth diseases type 2 (CMT2). Sharing similar...

  7. 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

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

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    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

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

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    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.

  10. Toxic neuropathies

    Directory of Open Access Journals (Sweden)

    Misra Usha

    2009-01-01

    Full Text Available Toxic neuropathies generally result in length dependent axonal neuropathy with the exception of diphtheria and a few toxic neuropathies. In spite of occurrence of diphtheria in India there is paucity of published reports on diphtheritic neuropathy. Arsenic neuropathy commonly occurs in Bengal and Bangladesh because of ground water contamination whereas in Punjab it is due to contamination of opium. Lead neuropathy is rare and has been reported in battery workers and silver refining workers. It produces motor neuropathy resulting in foot drop and wrist drop. Organophosphates are used as pesticides, industrial chemicals and food adulterant. Certain organophosphates such as triorthocresyl phosphate used for or oil adulteration inhibit neurotoxic esterase and result in a delayed type of axonal neuropathy. Alcohol related neuropathy is a controversial issue whether it is due to alcohol related toxicity or due to nutritional deficiencies. Indian studies have revealed that neuropathy occurs both in alcoholic and nonalcoholic cirrhosis. Hexane neuropathy is reported in screen printers and these cases highlight the need for better preventive and occupational measures. Iatrogenic toxic neuropathies have been reported with cisplatin and vincristine. Because of geographical, occupational and health related conditions toxic neuropathies are likely to be more common than reported and greater awareness is needed.

  11. Novel C12orf65 mutations in patients with axonal neuropathy and optic atrophy

    OpenAIRE

    Tucci,A; Liu, Y. T.; Preza, E; Pitceathly, R. D.; Chalasani, A.; Plagnol, V.; Land, J. M.; Trabzuni, D.; Ryten, M.; Jaunmuktane, Z.; Reilly, M.M.; Brandner, S; Hargreaves, I.; Hardy, J.; Singleton, A B

    2013-01-01

    Objective Charcot-Marie Tooth disease (CMT) forms a clinically and genetically heterogeneous group of disorders. Although a number of disease genes have been identified for CMT, the gene discovery for some complex form of CMT has lagged behind. The association of neuropathy and optic atrophy (also known as CMT type 6) has been described with autosomaldominant, recessive and X-linked modes of inheritance. Mutations in Mitofusin 2 have been found to cause dominant forms of CMT6. Phosphoribosylp...

  12. Chronic idiopathic axonal neuropathy and pain, treated with the endogenous lipid mediator palmitoylethanolamide: a case collection

    Directory of Open Access Journals (Sweden)

    Keppel Hesselink JM

    2013-09-01

    Full Text Available J M Keppel Hesselink Faculty of Medicine, University Witten/Herdecke, Germany Abstract: Chronic idiopathic axonal polyneuropathy is a frequent diagnosis in patients suffering from idiopathic polyneuropathy and neuropathic pain. No guidelines exist on how to treat these patients. To date, there are no results available from randomized clinical trials, and mostly classical neuropathic analgesics are prescribed, such as amitriptyline and gabapentine. However, the usefulness of these drugs is limited, as many patients remain in pain despite treatment, or suffer debilitating side effects. Palmitoylethanolamide (PEA is a new analgesic compound, tested in more than 4,000 patients in various clinical trials in a variety of patients suffering from various neuropathic pain states. It is available in Europe and the USA as a food supplement under the brand name PeaPure, and it is available for medical purposes in Italy and Spain under brand names Normast and Pelvilen. We present a case series of seven patients with an electrophysiological confirmed diagnosis of chronic idiopathic axonal polyneuropathy, suffering from neuropathic pains, mostly refractory to previous analgesics. In all these patients, PEA reduced pain significantly, without side effects. PEA can be administered in addition to other analgesics, without negative drug–drug interactions, or can be used as a stand-alone analgesic. Due to a favorable ratio between efficacy and safety, PEA should be considered more often as a treatment for neuropathic pain. Keywords: CIAP, polyneuropathy, treatment, neuropathic

  13. 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

  14. 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

  15. Botulinum toxin treatment of pes cavovarus in a child suffering from autosomal recessive axonal Charcot-Marie-Tooth neuropathy (AR-CMT2).

    Science.gov (United States)

    Tiffreau, V; Allart, E; Dangleterre, C; Boutry, N; Petit, F; Cuisset, J M; Thevenon, A

    2015-06-01

    In a 12-year old girl suffering from autosomal recessive axonal Charcot-Marie-Tooth (CMT) neuropathy, pes cavovarus was treated with botulinum toxin injection in the tibialis posterior. The patient underwent a clinical evaluation, video analysis of spatiotemporal gait parameters and dynamic foot plantar pressure assessment before treatment and then two weeks, three months and six months thereafter. The video gait analysis revealed a decrease in varus during the swing phase of gait. The dynamic foot plantar pressure decreased by 50% in the excessive pressure at the side of the foot six months after the injection (maximal pressure=42.6N/cm2 before treatment and 18.9 N/cm2 after 6 month). Botulinum toxin injection appears to be an efficacious means of correcting pes cavovarus in CMT disease. A larger-scale clinical trial is now required to evaluate the putative longer-term preventive effect of this treatment on the pes cavus deformity. PMID:24980632

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

    Institute of Scientific and Technical Information of China (English)

    张刚; 秦新月

    2014-01-01

    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.%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。

  17. 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

  18. 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...

  19. Comparison between retinal nerve fiber layer and macular thickness measured with OCT detecting progressive axonal loss following traumatic optic neuropathy Comparação entre as medidas da espessura da camada de fibras nervosas da retina e da mácula pela tomografia de coerência óptica na detecção da perda axonal progressiva decorrente à neuropatia óptica traumática

    OpenAIRE

    Leonardo Provetti Cunha; Luciana Virginia Ferreira Costa-Cunha; Roberto Freire Santiago Malta; Mário Luiz Ribeiro Monteiro

    2009-01-01

    PURPOSE: To compare the optical coherence tomography retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy in a longitudinal study. METHODS: Three patients with unilateral traumatic optic neuropathy were evaluated sequentially after trauma. Macular and retinal nerve fiber layer thickness measurements were obtained using optical coherence tomography weekly for five weeks and around the twelfth week after...

  20. 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.

  1. 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.

  2. Activation of axonal Kv7 channels in human peripheral nerve by flupirtine but not placebo - therapeutic potential for peripheral neuropathies: results of a randomised controlled trial

    OpenAIRE

    Fleckenstein, Johannes; Sittl, Ruth; Averbeck, Beate; Lang, Philip M; Irnich, Dominik; Richard W Carr

    2013-01-01

    Background: Flupirtine is an analgesic with muscle-relaxing properties that activates Kv7 potassium channels. Kv7 channels are expressed along myelinated and unmyelinated peripheral axons where their activation is expected to reduce axonal excitability and potentially contribute to flupirtine’s clinical profile. Trial design: To investigate the electrical excitability of peripheral myelinated axons following orally administered flupirtine, in-vitro experiments on isolated peripheral nerve s...

  3. Activation of axonal Kv7 channels in human peripheral nerve by flupirtine but not placebo - therapeutic potential for peripheral neuropathies: results of a randomised controlled trial

    OpenAIRE

    Fleckenstein, Johannes; Sittl, Ruth; Averbeck, Beate; Lang, Philip M; Irnich, Dominik; Richard W Carr

    2013-01-01

    Background Flupirtine is an analgesic with muscle-relaxing properties that activates Kv7 potassium channels. Kv7 channels are expressed along myelinated and unmyelinated peripheral axons where their activation is expected to reduce axonal excitability and potentially contribute to flupirtine’s clinical profile. Trial design To investigate the electrical excitability of peripheral myelinated axons following orally administered flupirtine, in-vitro experiments on isolated peripheral nerve segme...

  4. [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.

  5. 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

  6. [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.

  7. Diabetic Neuropathy

    Science.gov (United States)

    ... Awards Enhancing Diversity Find People About NINDS NINDS Diabetic Neuropathy Information Page Table of Contents (click to ... Trials Organizations Additional resources from MedlinePlus What is Diabetic Neuropathy? Diabetic neuropathy is a peripheral nerve disorder ...

  8. Axoval neuropathy as initial manifestation of primary amyloidosis: report of a case submitted to bone marrow transplantation Neuropatia axonal como manifestação inicial de amiloidose primária: relato de caso submetido a transplante de medula óssea

    OpenAIRE

    Orlando G. Povoas Barsottini; Adriano Arantes; Daniel Sigulem; José Mauro Kutner; Andreza Alice Feitosa Ribeiro; Luiz A. Moura; Nelson Hamerschlak

    2004-01-01

    Amyloidosis is a syndrome characterized by deposition of a highly insoluble protein material in the extracellular space that may affect several organs. It may be generalized and idiopathic (primary amyloidosis). We describe the case of a 48 years-old woman with axonal neuropathy associated with proteinuria, whose final investigation resulted in diagnosis of primary amyloidosis (AL). She was submitted to autologous bone marrow transplantation. We discuss some aspects related to diagnosis of ne...

  9. 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.

  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. 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.

  14. 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...

  15. [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.

  16. Axoval neuropathy as initial manifestation of primary amyloidosis: report of a case submitted to bone marrow transplantation Neuropatia axonal como manifestação inicial de amiloidose primária: relato de caso submetido a transplante de medula óssea

    Directory of Open Access Journals (Sweden)

    Orlando G. Povoas Barsottini

    2004-09-01

    Full Text Available Amyloidosis is a syndrome characterized by deposition of a highly insoluble protein material in the extracellular space that may affect several organs. It may be generalized and idiopathic (primary amyloidosis. We describe the case of a 48 years-old woman with axonal neuropathy associated with proteinuria, whose final investigation resulted in diagnosis of primary amyloidosis (AL. She was submitted to autologous bone marrow transplantation. We discuss some aspects related to diagnosis of neuropathy and current treatment of AL.A amiloidose é uma síndrome caracterizada pela deposição no meio extracelular de material protéico altamente insolúvel e que pode afetar vários órgãos. Pode ocorrer como doença generalizada e pode ser idiopática (amiloidose primária. Descrevemos o caso de mulher de 48 anos com neuropatia axonal associada a proteinúria na qual a investigação final resultou no diagnóstico de amiloidose primária (AL. Foi submetida a transplante autólogo de medula óssea sem complicações. Discutiremos aspectos relacionados ao diagnóstico da neuropatia e do tratamento atual da AL.

  17. [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.

  18. Auditory Neuropathy

    Science.gov (United States)

    ... field differ in their opinions about the potential benefits of hearing aids, cochlear implants, and other technologies for people with auditory neuropathy. Some professionals report that hearing aids and personal listening devices such as frequency modulation (FM) systems are ...

  19. Peripheral Neuropathy

    Science.gov (United States)

    ... injury (trauma) to a nerve, tumors, toxins, autoimmune responses, nutritional deficiencies, alcoholism, medical procedures, and vascular and metabolic disorders. Acquired peripheral neuropathies are caused by systemic disease, trauma from external agents, or infections or autoimmune disorders ...

  20. 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.

  1. 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.

  2. Abnormal Nutritional Factors in Patients Evaluated at a Neuropathy Center.

    Science.gov (United States)

    Latov, Norman; Vo, Mary L; Chin, Russell L; Carey, Bridget T; Langsdorf, Jennifer A; Feuer, Naomi T

    2016-06-01

    Abnormal concentrations of nutritional factors were found in 24.1% of 187 patients with neuropathy who were newly seen at our academic neuropathy referral center over a 1-year period. All patients presented with sensory axonal or small fiber neuropathy. In 7.3%, they were present in association with at least one other identifiable cause for neuropathy. Elevated levels of pyridoxal phosphate or mercury occurred more frequently than deficiencies in vitamins B1, B12, or B6. The nutritional abnormalities are amenable to correction by dietary intervention. PMID:27224436

  3. Critical illness neuropathy

    Directory of Open Access Journals (Sweden)

    Vijayan J

    2005-01-01

    Full Text Available The neuromuscular syndrome of acute limb and respiratory weakness that commonly accompanies patients with multi-organ failure and sepsis constitutes critical illness polyneuropathy. It is a major cause of difficulty in weaning off the patient from the ventilator after respiratory and cardiac causes have been excluded. It is usually an axonal motor-sensory polyneuropathy, and is usually associated with or accompanied with a coma producing septic encephalopathy. The neuropathy is usually not apparent until the patient′s encephalopathy has peaked, and may be noted only when the brain dysfunction is resolving. Patients usually have a protracted hospital course complicated by multi-organ failure and the systemic inflammatory response syndrome. Elevated serum glucose levels and reduced albumin are risk factors for nerve dysfunction, as is prolonged intensive care unit stay. Polyneuropathy may develop after only one week of the systemic inflammatory response syndrome, but the frequency tends to correlate with the duration of the severe illness.

  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. 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...

  6. 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.

  7. Comparison between retinal nerve fiber layer and macular thickness measured with OCT detecting progressive axonal loss following traumatic optic neuropathy Comparação entre as medidas da espessura da camada de fibras nervosas da retina e da mácula pela tomografia de coerência óptica na detecção da perda axonal progressiva decorrente à neuropatia óptica traumática

    Directory of Open Access Journals (Sweden)

    Leonardo Provetti Cunha

    2009-10-01

    Full Text Available PURPOSE: To compare the optical coherence tomography retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy in a longitudinal study. METHODS: Three patients with unilateral traumatic optic neuropathy were evaluated sequentially after trauma. Macular and retinal nerve fiber layer thickness measurements were obtained using optical coherence tomography weekly for five weeks and around the twelfth week after trauma. RESULTS: All patients showed progressive macular and retinal nerve fiber layer thickness reduction. The mean retinal nerve fiber layer thickness on the first week was 114 μm and reduced sequentially over the first five weeks and was 46 μm on the twelfth week. For macular parameters, the mean average thickness on the first week was 248 μm and also reduced over the first five weeks and was 218 μm on the twelfth week. When compared to the initial measurement, macular thickness average reduction rate at the 12th week was 14% while peripapillary retinal nerve fiber layer thickness average reduction rate was 59%. CONCLUSIONS: Although both measurements reduce significantly after trauma, retinal nerve fiber layer thickness measurements show greater and faster retinal neural reduction if compared to macular thickness measurements in traumatic optic neuropathy.OBJETIVO: Comparar as medidas da espessura da camada de fibras nervosas da retina e macular obtidas pela tomografia de coerência óptica na detecção da perda axonal progressiva após neuropatia óptica traumática aguda e durante o seguimento clínico. MÉTODOS: Três pacientes com neuropatia óptica traumática unilateral aguda foram avaliados sequencialmente após o trauma. Medidas da espessura macular e da camada de fibras nervosas da retina foram obtidas pela tomografia de coerência óptica semanalmente por 5 semanas consecutivas e ao redor da décima segunda semana após o trauma

  8. Sympathetic vasoconstrictor nerve function in alcoholic neuropathy

    DEFF Research Database (Denmark)

    Jensen, K; Andersen, K; Smith, T;

    1984-01-01

    The peripheral sympathetic vasomotor nerve function was investigated in 18 male chronic alcoholics admitted for intellectual impairment or polyneuropathy. By means of the local 133Xenon washout technique, the sympathetic veno-arteriolar axon-reflex was studied. This normally is responsible for a 50...... (18% and 48% decrease respectively). However, in three patients with moderate neuropathy, and in one patient with no signs of neuropathy, this veno-arteriolar reflex was absent, indicating dysfunction of the peripheral sympathetic adrenergic nerve fibres. The three patients also showed a lesser degree...

  9. 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

  10. Chronic obstructive pulmonary disease and peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Gupta Prem

    2006-01-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is the fourth leading cause of death world-wide and a further increase in the prevalence as well as mortality of the disease is predicted for coming decades. There is now an increased appreciation for the need to build awareness regarding COPD and to help the thousands of people who suffer from this disease and die prematurely from COPD or its associated complication(s. Peripheral neuropathy in COPD has received scanty attention despite the fact that very often clinicians come across COPD patients having clinical features suggestive of peripheral neuropathy. Electrophysiological tests like nerve conduction studies are required to distinguish between axonal and demyelinating type of disorder that cannot be analyzed by clinical examination alone. However, various studies addressing peripheral neuropathy in COPD carried out so far have included patients with COPD having markedly varying baseline characteristics like severe hypoxemia, elderly patients, those with long duration of illness, etc. that are not uniform across the studies and make it difficult to interpret the results to a consistent conclusion. Almost one-third of COPD patients have clinical evidence of peripheral neuropathy and two-thirds have electrophysiological abnormalities. Some patients with no clinical indication of peripheral neuropathy do have electrophysiological deficit suggestive of peripheral neuropathy. The more frequent presentation consists of a polyneuropathy that is subclinical or with predominantly sensory signs, and the neurophysiological and pathological features of predominantly axonal neuropathy. The presumed etiopathogenic factors are multiple: chronic hypoxia, tobacco smoke, alcoholism, malnutrition and adverse effects of certain drugs.

  11. 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.

  12. Nodes of Ranvier and Paranodes in Chronic Acquired Neuropathies

    OpenAIRE

    Carmen Cifuentes-Diaz; Odile Dubourg; Theano Irinopoulou; Marc Vigny; Sylvie Lachkar; Laurence Decker; Patrick Charnay; Natalia Denisenko; Thierry Maisonobe; Jean-Marc Léger; Karine Viala; Jean-Jacques Hauw; Jean-Antoine Girault

    2011-01-01

    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 per...

  13. 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.

  14. 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.

  15. 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.

  16. Clinicopathological study of vasculitic peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    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

  17. Streptozotocin induced diabetes as a model of phrenic nerve neuropathy in rats.

    Science.gov (United States)

    Rodrigues Filho, Omar Andrade; Fazan, Valéria Paula Sassoli

    2006-03-15

    Phrenic neuropathies are increasingly recognized in peripheral neuropathies but reports on experimental models of the phrenic nerves diabetic neuropathy are scanty. In the present study, we investigated the phrenic nerve neuropathy, due to experimental diabetes induced by streptozotocin (STZ) and the evolution of this neuropathy in diabetic rats treated with insulin. Proximal and distal segments of the left and right phrenic nerves were morphologically and morphometrically evaluated, from rats rendered diabetic for 12 weeks, by injection of STZ. Control rats received vehicle. Treated rats received a single subcutaneous injection of insulin on a daily basis. The nerves were prepared for light microcopy study by means of conventional techniques. Morphometry was carried out with the aid of computer software. The phrenic nerves of diabetic rats showed smaller myelinated axon diameters compared to controls. The g ratio was significantly smaller for myelinated fibers from diabetic rats compared to controls. Insulin treatment prevented these alterations. Histograms of size distribution for myelinated fibers and axons from control rats were bimodal. For diabetic animals, the myelinated fiber histogram was bimodal while the axon distribution turned to be unimodal. Insulin treatment also prevented these alterations. Our results confirm the phrenic nerve neuropathy in this experimental model of diabetes and suggest that conventional insulin treatment was able to prevent and/or correct the myelinated axon commitment by diabetes. PMID:16125783

  18. 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.

  19. 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.

  20. Entrapment neuropathies III: lower limb.

    Science.gov (United States)

    Beltran, Luis S; Bencardino, Jenny; Ghazikhanian, Varand; Beltran, Javier

    2010-11-01

    Clinicians frequently encounter compressive neuropathies of the lower extremity. The clinical history and physical examination, along with electrodiagnostic testing and imaging studies, lead to the correct diagnosis. The imaging characteristics of the compression neuropathies can include acute and chronic changes in the nerves and the muscles they innervate. We provide a detailed review of compression neuropathies of the lower extremity with an emphasis on magnetic resonance (MR) imaging characteristics. We discuss the clinical presentation, etiology, anatomical location, and MR imaging appearance of these neuropathies, including the piriformis syndrome, iliacus syndrome, saphenous neuropathy, obturator neuropathy, lateral femoral cutaneous neuropathy (meralgia paresthetica), proximal tibial neuropathy, common peroneal neuropathy, deep peroneal neuropathy, superficial peroneal neuropathy, tarsal tunnel syndrome, Baxter's neuropathy, jogger's foot, sural neuropathy, and Morton's neuroma. PMID:21072728

  1. Fcγ receptor-mediated inflammation inhibits axon regeneration.

    Directory of Open Access Journals (Sweden)

    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.

  2. 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).

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

    Directory of Open Access Journals (Sweden)

    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. [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.

  5. Foot neuropathy in rheumatoid arthritis patients: clinical, electrophysiological, and ultrasound studies

    Directory of Open Access Journals (Sweden)

    Abd El-Samad I El-Hewala

    2016-01-01

    Conclusion Peripheral nerve affection is common in the rheumatoid foot, irrespective of the disease activity status. The most common neuropathies were posterior tarsal tunnel syndrome, peroneal nerve entrapment at the fibular neck, and pure sensory axonal neuropathy. A positive power Doppler signal and bone erosions of the ankle joint, detected by MSUS, were associated with RA disease activity. Electrophysiology was superior to MSUS for the diagnosis of posterior tarsal tunnel syndrome.

  6. Motor Axon Pathfinding

    OpenAIRE

    Bonanomi, Dario; Pfaff, Samuel L

    2010-01-01

    Motor neurons are functionally related, but represent a diverse collection of cells that show strict preferences for specific axon pathways during embryonic development. In this article, we describe the ligands and receptors that guide motor axons as they extend toward their peripheral muscle targets. Motor neurons share similar guidance molecules with many other neuronal types, thus one challenge in the field of axon guidance has been to understand how the vast complexity of brain connection...

  7. 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.

  8. 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.

  9. 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.

  10. 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....

  11. [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. PMID:27474733

  12. [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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. [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.

  18. Motor axon loss is associated with hand dysfunction in Charcot-Marie-Tooth disease 1a.

    NARCIS (Netherlands)

    Videler, A.J.; Dijk, J.P. van; Beelen, A.; Visser, M. de; Nollet, F.; Schaik, I.N. van

    2008-01-01

    BACKGROUND: Charcot Marie Tooth type 1a (CMT1a) is a primarily demyelinating neuropathy, characterized by slowly progressive muscle weakness, atrophy, and sensory loss, and is most pronounced in both feet and hands. There is increasing evidence that muscle weakness is determined by motor axonal dysf

  19. Leprosy neuropathy: clinical presentations.

    Science.gov (United States)

    Nascimento, Osvaldo J M

    2013-09-01

    Leprosy is a chronic infectious peripheral neuropathy caused by Mycobacterium leprae. The different clinical presentations of the disease are determined by the quality of the host immune response. Early detection of leprosy and treatment by multidrug therapy are the most important steps in preventing deformity and disability. Thus the early recognition of the clinical leprosy presentation is essential. Mononeuritis, mononeuritis multiplex (MM), polyneuritis (MM summation) are the most frequent. The frequent anesthetic skin lesions are absent in the pure neuritic leprosy presentation form. Isolated peripheral nerve involvement is common, including the cranial ones. Arthritic presentation is occasionally seen, usually misdiagnosed as rheumatoid arthritis. Attention should be given to autonomic dysfunctions in leprosy. There are clinical presentations with severe neuropathic pain - painful small-fiber neuropathy. Leprous late-onset neuropathy (LLON) clinical presentation should be considered facing a patient who develop an inflammatory neuropathy many years after a previous skin leprosy treatment. PMID:24141500

  20. 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"…

  1. Determinants of axonal regeneration

    OpenAIRE

    Frisén, J

    1997-01-01

    Axons often regrow to their targets and lost functions may be restored after an injury in the peripheral nervous system. In contrast, axonal regeneration is generally very limited after injuries in the central nervous system, and functional impairment is usually permanent. The regenerative capacity depends on intrinsic neuronal factors as weil as the interaction of neurons with other cells. Glial cells may, in different situations, either support or inhibit axo...

  2. 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.

  3. Peripheral Glia Have a Pivotal Role in the Initial Response to Axon Degeneration of Peripheral Sensory Neurons in Zebrafish

    OpenAIRE

    Holly M Pope; Voigt, Mark M.

    2014-01-01

    Axon degeneration is a feature of many peripheral neuropathies. Understanding the organismal response to this degeneration may aid in identifying new therapeutic targets for treatment. Using a transgenic zebrafish line expressing a bacterial nitroreductase (Ntr)/mCherry fusion protein in the peripheral sensory neurons of the V, VII, IX, and X cranial nerves, we were able to induce and visualize the pathology of axon degeneration in vivo. Exposure of 4 days post fertilization Ntr larvae to the...

  4. Peripheral Neuropathy and Agent Orange

    Science.gov (United States)

    ... Enter ZIP code here Peripheral Neuropathy and Agent Orange VA presumes Veterans' early-onset peripheral neuropathy is related to their exposure to Agent Orange or other herbicides during service when the disease ...

  5. 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.

  6. Megaoesophagus due to acrylamide neuropathy.

    OpenAIRE

    Satchell, P M; McLeod, J G

    1981-01-01

    Greyhound dogs exposed to oral acrylamide for a period of eight weeks developed a sensorimotor peripheral neuropathy that had many features in common with acrylamide neuropathy seen in other species. Most of the animals also developed the clinical and radiological features of megaoesophagus. The association of neuropathy and megaoesophagus suggests that an axonopathy of the vagus may be an aetiological factor in this disorder.

  7. 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......) are not altered in circulating blood cells in diabetic autonomic neuropathy. Thus, a generalized up-regulation of adrenoceptors does not occur in diabetic autonomic neuropathy....

  8. 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

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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).

  14. Sensory and motor neuropathy in a Border Collie.

    Science.gov (United States)

    Harkin, Kenneth R; Cash, Walter C; Shelton, G Diane

    2005-10-15

    A 5-month-old female Border Collie was evaluated because of progressive hind limb ataxia. The predominant clinical findings suggested a sensory neuropathy. Sensory nerve conduction velocity was absent in the tibial, common peroneal, and radial nerves and was decreased in the ulnar nerve; motor nerve conduction velocity was decreased in the tibial, common peroneal, and ulnar nerves. Histologic examination of nerve biopsy specimens revealed considerable nerve fiber depletion; some tissue sections had myelin ovoids, foamy macrophages, and axonal degeneration in remaining fibers. Marked depletion of most myelinated fibers within the peroneal nerve (a mixed sensory and motor nerve) supported the electrodiagnostic findings indicative of sensorimotor neuropathy. Progressive deterioration in motor function occurred over the following 19 months until the dog was euthanatized. A hereditary link was not established, but a littermate was similarly affected. The hereditary characteristic of this disease requires further investigation. PMID:16266014

  15. 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.

  16. 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

  17. 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…

  18. 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...

  19. Diabetic Neuropathies: The Nerve Damage of Diabetes

    Science.gov (United States)

    ... Organizations (PDF, 293 KB). Alternate Language URL Español Diabetic Neuropathies: The Nerve Damage of Diabetes Page Content ... treated? Points to Remember Clinical Trials What are diabetic neuropathies? Diabetic neuropathies are a family of nerve ...

  20. 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

  1. Painful peripheral neuropathy

    OpenAIRE

    Sun, Bo; Xu-sheng HUANG

    2013-01-01

    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...

  2. Multifocal motor neuropathy

    OpenAIRE

    Thy P Nguyen; Vinay Chaudhry

    2011-01-01

    Multifocal motor neuropathy (MMN) is a unique disorder characterized by slowly progressive, asymmetric, distal and upper limb predominant weakness without significant sensory abnormalities. Electrophysiology is crucial to the diagnosis, revealing the hallmark partial conduction block. MMN is considered immune mediated due to the association with anti-GM1 antibodies and the response to immunomodulatory treatment. It is paramount to recognize MMN from other motor neuronopathies or peripheral ne...

  3. Prolonged high frequency electrical stimulation is lethal to motor axons of mice heterozygously deficient for the myelin protein P0 gene

    DEFF Research Database (Denmark)

    Alvarez, Susana; Moldovan, Mihai; Krarup, Christian

    2013-01-01

    The relationship between dysmyelination and the progression of neuropathy in Charcot-Marie-Tooth (CMT) hereditary polyneuropathy is unclear. Mice heterozygously deficient for the myelin protein P₀ gene (P₀+/-) are indistinguishable from wild-type (WT) at birth and then develop a slowly progressing...... demyelinating neuropathy reminiscent of CMT Type 1b. Accumulating evidence suggests that impulse conduction can become lethal to acutely demyelinated central and peripheral axons. Here we investigated the vulnerability of motor axons to long-lasting, high-frequency repetitive stimulation (RS) in P₀+/- mice...

  4. Brain gangliosides in axon-myelin stability and axon regeneration

    OpenAIRE

    Schnaar, Ronald L.

    2009-01-01

    Gangliosides, sialic acid-bearing glycosphingolipids, are expressed at high abundance and complexity in the brain. Altered ganglioside expression results in neural disorders, including seizures and axon degeneration. Brain gangliosides function, in part, by interacting with a ganglioside-binding lectin, myelin-associated glycoprotein (MAG). MAG, on the innermost wrap of the myelin sheath, binds to gangliosides GD1a and GT1b on axons. MAG-ganglioside binding ensures optimal axon-myelin cell-ce...

  5. 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.

  6. 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...

  7. Paclitaxel causes degeneration of both central and peripheral axon branches of dorsal root ganglia in mice

    OpenAIRE

    Tasnim, Aniqa; Rammelkamp, Zoe; Slusher, Amy B.; Wozniak, Krystyna; Slusher, Barbara S.; Farah, Mohamed H.

    2016-01-01

    Background Peripheral neuropathy is a common and dose-limiting side effect of many cancer chemotherapies. The taxane agents, including paclitaxel (Taxol®), are effective chemotherapeutic drugs but cause degeneration of predominantly large myelinated afferent sensory fibers of the peripheral nervous system in humans and animal models. Dorsal root ganglia (DRG) neurons are sensory neurons that have unipolar axons each with two branches: peripheral and central. While taxane agents induce degener...

  8. 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. PMID:27350989

  9. Age-related intra-axonal accumulation of neurofilaments in the dorsal column nuclei of the cat brainstem: a light and electron microscopic immunohistochemical study.

    Science.gov (United States)

    Zhang, J H; Sampogna, S; Morales, F R; Chase, M H

    1998-06-29

    In the present study, we examined the age-related intra-axonal accumulation of neurofilaments in the dorsal column nuclei of the cat by using immunohistochemical techniques combined with light and electron microscopy. Light microscopic analysis revealed oval or circular immunostained structures in the dorsal column nuclei of old cats. These immunostained structures were not observed in the material obtained from adult controls. Under the electron microscope, it was discovered that the immunostained structures were greatly enlarged axons with disrupted myelin sheaths. These enlarged axons contained massive accumulations of neurofilaments, some mitochondria, vacuoles and dense granules. The abnormalities of the myelin sheaths included the breaking of myelin at several locations, a splitting and ballooning in the myelin lamellae of the sheath and a distended periaxonal space between the axon and myelin sheaths. These ultrastructural changes resembled the degenerative alterations that have been observed in the axons of human and animals suffering from a number of pathological conditions, including giant axonal neuropathy and toxic neuropathy. Therefore, severely altered axons with intra-axonal accumulation of neurofilaments appear to reflect chronic degenerative changes that are a component of the aging process. PMID:9666164

  10. 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

  11. 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.

  12. Clinical and neurophysiologic characterization of an European family with hereditary sensory neuropathy, paroxysmal cough and gastroesophageal reflux

    Directory of Open Access Journals (Sweden)

    Pedro Barros

    2014-04-01

    Full Text Available In 2002, Spring et al reported a family with an autosomal dominant form of hereditary sensory neuropathy; patients also presented adult onset of gastroesophageal reflux and cough. Since then, no further families have been described. Objective: To study a new Portuguese family with these characteristics. Method: To describe the clinical and neurophysiologic characteristics of one family with features of sensory neuropathy associated with cough and gastroesophageal erflux. Results: Three of five siblings presented a similar history of paroxysmal cough (5th decade. About a decade later they experienced numbness and paraesthesia in the feets and in all cases there was evidence of an axonal sensory neuropathy. A history of gastroesophageal reflux of variable severity and age of onset was also present. Discussion: Molecular genetic studies have demonstrated genetic heterogeneity between the hereditary sensory neuropathy type 1 subtypes. The identification of these families is of major importance because further work is required to identify the underlying genetic defect.

  13. Warfarin improves neuropathy in monoclonal gammopathy of undetermined significance.

    Science.gov (United States)

    Henry Gomez, Teny; Holkova, Beata; Noreika, Danielle; Del Fabbro, Egidio

    2016-01-01

    We report a case of a 60-year-old man who was referred to a palliative care clinic with monoclonal gammopathy of undetermined significance (MGUS)-associated neuropathy, responding to a therapeutic trial of warfarin. Electromyography showed distal symmetric sensory axonal neuropathy. The patient reported having had improvement of his neuropathic symptoms while taking warfarin postoperatively for thromboprophylaxis 1 year prior, and recurrence of his symptoms after the warfarin was discontinued. The patient was rechallenged with a trial of warfarin, targeting an international normalised ratio of 1.5-2.0. His pain scores decreased from 5/10 to 3/10 at 1 month and symptom improvement was maintained through 24 months of follow-up. Warfarin had a remarkable impact on our patient's symptoms and quality of life. The mechanisms mediating the symptomatic benefit with warfarin are unclear; however, a placebo effect is unlikely. Further studies may help guide the use of warfarin for MGUS-associated neuropathy. PMID:27317760

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Vincristine-Induced Cranial Neuropathy

    OpenAIRE

    TALEBIAN, Ahmad; Razeieh GOUDARZI; Mohammadzadeh, Mahdi; Mirzadeh, Azadeh Sadat

    2014-01-01

    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 (0/0...

  19. 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.

  20. Peripheral glia have a pivotal role in the initial response to axon degeneration of peripheral sensory neurons in zebrafish.

    Science.gov (United States)

    Pope, Holly M; Voigt, Mark M

    2014-01-01

    Axon degeneration is a feature of many peripheral neuropathies. Understanding the organismal response to this degeneration may aid in identifying new therapeutic targets for treatment. Using a transgenic zebrafish line expressing a bacterial nitroreductase (Ntr)/mCherry fusion protein in the peripheral sensory neurons of the V, VII, IX, and X cranial nerves, we were able to induce and visualize the pathology of axon degeneration in vivo. Exposure of 4 days post fertilization Ntr larvae to the prodrug metronidazole (Met), which Ntr metabolizes into cytotoxic metabolites, resulted in dose-dependent cell death and axon degeneration. This was limited to the Ntr-expressing sensory neurons, as neighboring glia and motor axons were unaffected. Cell death was rapid, becoming apparent 3-4 hours after Met treatment, and was followed by phagocytosis of soma and axon debris by cells within the nerves and ganglia beginning at 4-5 hours of exposure. Although neutrophils appear to be activated in response to the degenerating neurons, they did not accumulate at the sites of degeneration. In contrast, macrophages were found to be attracted to the sites of the degenerating axons, where they phagocytosed debris. We demonstrated that peripheral glia are critical for both the phagocytosis and inflammatory response to degenerating neurons: mutants that lack all peripheral glia (foxD3-/-; Ntr) exhibit a much reduced reaction to axonal degeneration, resulting in a dramatic decrease in the clearance of debris, and impaired macrophage recruitment. Overall, these results show that this zebrafish model of peripheral sensory axon degeneration exhibits many aspects common to peripheral neuropathies and that peripheral glia play an important role in the initial response to this process. PMID:25058656

  1. Peripheral glia have a pivotal role in the initial response to axon degeneration of peripheral sensory neurons in zebrafish.

    Directory of Open Access Journals (Sweden)

    Holly M Pope

    Full Text Available Axon degeneration is a feature of many peripheral neuropathies. Understanding the organismal response to this degeneration may aid in identifying new therapeutic targets for treatment. Using a transgenic zebrafish line expressing a bacterial nitroreductase (Ntr/mCherry fusion protein in the peripheral sensory neurons of the V, VII, IX, and X cranial nerves, we were able to induce and visualize the pathology of axon degeneration in vivo. Exposure of 4 days post fertilization Ntr larvae to the prodrug metronidazole (Met, which Ntr metabolizes into cytotoxic metabolites, resulted in dose-dependent cell death and axon degeneration. This was limited to the Ntr-expressing sensory neurons, as neighboring glia and motor axons were unaffected. Cell death was rapid, becoming apparent 3-4 hours after Met treatment, and was followed by phagocytosis of soma and axon debris by cells within the nerves and ganglia beginning at 4-5 hours of exposure. Although neutrophils appear to be activated in response to the degenerating neurons, they did not accumulate at the sites of degeneration. In contrast, macrophages were found to be attracted to the sites of the degenerating axons, where they phagocytosed debris. We demonstrated that peripheral glia are critical for both the phagocytosis and inflammatory response to degenerating neurons: mutants that lack all peripheral glia (foxD3-/-; Ntr exhibit a much reduced reaction to axonal degeneration, resulting in a dramatic decrease in the clearance of debris, and impaired macrophage recruitment. Overall, these results show that this zebrafish model of peripheral sensory axon degeneration exhibits many aspects common to peripheral neuropathies and that peripheral glia play an important role in the initial response to this process.

  2. Leber Hereditary Optic Neuropathy

    Directory of Open Access Journals (Sweden)

    Kopishinskaya S.V.

    2014-06-01

    Full Text Available Leber optic neuropathy is mitochondrial neurodegenerative disease manifested by progressive visual deterioration due to optic nerve atrophy. It is most frequently manifested in young people aged from 18 to 30, male patients prevailing. The disease is characterized by maternal inheritance, and the inheritance of a feature discontinues in men. In 95% cases Leber hereditary optic neuropathology is due to one of three known mitochondrial DNA mutations, its type being important in relation to the disease prognosis. The disease course has a number of succeeding stages: preclinical, acute and chronic (atrophic. The disease diagnosis is based on the characteristic clinical presentation of sequential impairment of both eyes forming central scotoma, the analysis of family history and detection of specific mutations. The present clinical observation illustrates the difficulties in Leber disease diagnosis.

  3. [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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. Local translation and directional steering in axons

    OpenAIRE

    Lin, Andrew C; Holt, Christine E.

    2007-01-01

    The assembly of functional neural circuits in the developing brain requires neurons to extend axons to the correct targets. This in turn requires the navigating tips of axons to respond appropriately to guidance cues present along the axonal pathway, despite being cellular ‘outposts' far from the soma. Work over the past few years has demonstrated a critical role for local translation within the axon in this process in vitro, making axon guidance another process that requires spatially locali...

  9. 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

  10. 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.

  11. 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. PMID:22592935

  12. Mutation in PNKP presenting initially as axonal Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Pedroso, José Luiz; Rocha, Clarissa R R; Macedo-Souza, Lucia I; De Mario, Vitor; Marques, Wilson; Barsottini, Orlando G P; Bulle Oliveira, Acary S; Menck, Carlos F M; Kok, Fernando

    2015-12-01

    PNKP (polynucleotide kinase 3'-phosphatase, OMIM #605610) product is involved in the repair of strand breaks and base damage in the DNA molecule mainly caused by radical oxygen species. Deleterious variants affecting this gene have been previously associated with microcephaly, epilepsy, and developmental delay.(1) According to a previous report, homozygous loss-of-function substitution in PNKP was associated with cerebellar atrophy, neuropathy, microcephaly, epilepsy, and intellectual disability.(2) Recently, whole-exome sequencing (WES) performed in a cohort of Portuguese families with ataxia with oculomotor apraxia (AOA) disclosed pathogenic variants in PNKP in 11 individuals. Other clinical features in that study included neuropathy, dystonia, cognitive impairment, decreased vibration sense, pyramidal signs, mild elevation in α-fetoprotein, and low levels of albumin. This condition was named AOA type 4 (OMIM #616267), as the phenotype of AOA has been previously associated with 3 other genes: APTX, SETX, and PIK3R5.(3) Altogether, these reports demonstrate the great phenotypic diversity associated with PNKP mutations. In this article, we further enlarge this variability by demonstrating that early-onset axonal sensory-motor neuropathy (or axonal Charcot-Marie-Tooth (CMT) disease) followed years later by ataxia without oculomotor apraxia can be caused by deleterious variants in PNKP. Full consent was obtained from the patient and his parents for this publication. This study was approved by institutional ethics committees. PMID:27066567

  13. 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

  14. 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

  15. 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....

  16. Short-term peripheral nerve stimulation ameliorates axonal dysfunction after spinal cord injury.

    Science.gov (United States)

    Lee, Michael; Kiernan, Matthew C; Macefield, Vaughan G; Lee, Bonne B; Lin, Cindy S-Y

    2015-05-01

    There is accumulating evidence that peripheral motor axons deteriorate following spinal cord injury (SCI). Secondary axonal dysfunction can exacerbate muscle atrophy, contribute to peripheral neuropathies and neuropathic pain, and lead to further functional impairment. In an attempt to ameliorate the adverse downstream effects that developed following SCI, we investigated the effects of a short-term peripheral nerve stimulation (PNS) program on motor axonal excitability in 22 SCI patients. Axonal excitability studies were undertaken in the median and common peroneal nerves (CPN) bilaterally before and after a 6-wk unilateral PNS program. PNS was delivered percutaneously over the median nerve at the wrist and CPN around the fibular head, and the compound muscle action potential (CMAP) from the abductor pollicis brevis and tibialis anterior was recorded. Stimulus intensity was above motor threshold, and pulses (450 μs) were delivered at 100 Hz with a 2-s on/off cycle for 30 min 5 days/wk. SCI patients had consistently high thresholds with a reduced CMAP consistent with axonal loss; in some patients the peripheral nerves were completely inexcitable. Nerve excitability studies revealed profound changes in membrane potential, with a "fanned-in" appearance in threshold electrotonus, consistent with membrane depolarization, and significantly reduced superexcitability during the recovery cycle. These membrane dysfunctions were ameliorated after 6 wk of PNS, which produced a significant hyperpolarizing effect. The contralateral, nonstimulated nerves remained depolarized. Short-term PNS reversed axonal dysfunction following SCI, may provide an opportunity to prevent chronic changes in axonal and muscular function, and may improve rehabilitation outcomes. PMID:25787956

  17. 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

  18. Entrapment neuropathies in diabetes mellitus.

    Science.gov (United States)

    Rota, Eugenia; Morelli, Nicola

    2016-09-15

    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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Outsourcing CREB translation to axons to survive

    OpenAIRE

    Lin, Andrew C; Holt, Christine E.

    2008-01-01

    Nerve growth factor induces sensory neuron survival via retrograde signalling from the axon to the cell body. Local translation of the transcription factor CREB in the axon, followed by its transport to the nucleus, is involved in this process.

  4. Axon damage and repair in multiple sclerosis.

    OpenAIRE

    Perry, V.H.; Anthony, D. C.

    1999-01-01

    It is well known that within long-standing multiple sclerosis (MS) lesions there is axonal loss but whether it is an early or late event has been more difficult to establish. The use of immunocytochemical methods that reveal axonal end-bulbs is a valuable approach to investigating acute axonal injury in human pathological material. The application of these techniques to multiple sclerosis tissue reveals evidence of axonal injury in acute lesions; the distribution of the end-bulbs in acute and...

  5. 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.

  6. 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.

  7. Axonal change in minor head injury.

    Science.gov (United States)

    Povlishock, J T; Becker, D P; Cheng, C L; Vaughan, G W

    1983-05-01

    Anterograde axonal transport of horseradish peroxidase (HRP) in selected cerebral and cerebellar efferents was studied in cats subjected to minor head injury. After trauma, the animals were allowed to survive from one to 24 hours, when they were perfused with aldehydes and processed for the light and electron microscopic visualization of the peroxidase reaction product. By light microscopy, the brain injury elicited an initial intra-axonal peroxidase pooling. With longer post-traumatic survival, HRP pooling increased in size, demonstrated frequent lobulation, and ultimately formed large ball- or club-like swellings which suggested frank axonal separation from the distal axonal segment. Ultrastructural examination revealed that the initial intra-axonal peroxidase pooling was associated with organelle accumulation which occurred without any other form of axonal change or related parenchymal or vascular damage. This accumulation of organelles increased with time and was associated with conspicuous axonal swelling. Ultimately these organelle-laden swellings lost continuity with the distal axonal segment and the axonal swelling was either completely invested by a thin myelin sheath or protruded without myelin investment into the brain parenchyma. This study suggests that axonal change is a consistent feature of minor head injury. Since these axonal changes occurred without any evidence of focal parenchymal or vascular damage, minor brain injury may ultimately disrupt axons without physically shearing or tearing them. PMID:6188807

  8. 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

  9. [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.

  10. 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.

  11. 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.

  12. 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.

  13. Tetrahydrocurcumin exerts protective effect on vincristine induced neuropathy: Behavioral, biochemical, neurophysiological and histological evidence.

    Science.gov (United States)

    Greeshma, N; Prasanth, K G; Balaji, Bhaskar

    2015-08-01

    Hyperalgesia, allodynia, delayed motor nerve conduction velocity, oxidative stress and axonal damage are signs and symptoms of chemotherapy induced peripheral neuropathy (CIPN). Present treatment/preventive strategies of CIPN are futile and the neuropathy may even lead to discontinuation of chemotherapy. In this study, we evaluated the protective effect of tetrahydrocurcumin (THC) 40 and 80mg/kg in experimental vincristine induced neuropathy in rats. Hyperalgesia was assessed by hot plate (thermal), Randall-Selitto (mechanical) test, allodynia was assessed by cold plate (thermal) test, functional loss was measured by sciatic function index, nociception was evaluated by formalin test. Neurophysiological recordings were carried out to assess motor nerve conduction velocity. Total calcium levels, oxidative stress and TNF-α was measured in sciatic nerve tissue homogenate to assess neuropathy. Histopathological changes was observed on sciatic nerve to assess the protective effect of THC against the vincristine. Pregabalin was used as a standard in this study. Rats administered with THC at 80mg/kg significantly attenuated the vincristine induced neuropathic pain manifestations which may be due to its multiple actions including anti-nociceptive, anti-inflammatory, neuroprotective, calcium inhibitory and antioxidant effect. This study delineates that THC can be a promising candidate for the prevention of CIPN by chemotherapeutic agents. PMID:26102012

  14. 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

  15. 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.

  16. Peripheral Nerve Diffusion Tensor Imaging: Assessment of Axon and Myelin Sheath Integrity.

    Directory of Open Access Journals (Sweden)

    A Heckel

    Full Text Available To investigate the potential of diffusion tensor imaging (DTI parameters as in-vivo biomarkers of axon and myelin sheath integrity of the median nerve in the carpal tunnel as validated by correlation with electrophysiology.MRI examinations at 3T including DTI were conducted on wrists in 30 healthy subjects. After manual segmentation of the median nerve quantitative analysis of fractional anisotropy (FA as well as axial, radial and mean diffusivity (AD, RD, and MD was carried out. Pairwise Pearson correlations with electrophysiological parameters comprising sensory nerve action potential (SNAP and compound muscle action potential (CMAP as markers of axon integrity, and distal motor latency (dml and sensory nerve conduction velocity (sNCV as markers of myelin sheath integrity were computed. The significance criterion was set at P=0.05, Bonferroni corrected for multiple comparisons.DTI parameters showed a distinct proximal-to-distal profile with FA, MD, and RD extrema coinciding in the center of the carpal tunnel. AD correlated with CMAP (r=0.50, p=0.04, Bonf. corr. but not with markers of myelin sheath integrity. RD correlated with sNCV (r=-0.53, p=0.02, Bonf. corr. but not with markers of axon integrity. FA correlated with dml (r=-0.63, p=0.002, Bonf. corr. and sNCV (r=0.68, p=0.001, Bonf. corr. but not with markers of axon integrity.AD reflects axon integrity, while RD (and FA reflect myelin sheath integrity as validated by correlation with electrophysiology. DTI parameters consistently indicate a slight decrease of structural integrity in the carpal tunnel as a physiological site of median nerve entrapment. DTI is particularly sensitive, since these findings are observed in healthy participants. Our results encourage future studies to evaluate the potential of DTI in differentiating axon from myelin sheath injury in patients with manifest peripheral neuropathies.

  17. 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.

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

    Science.gov (United States)

    FitzGibbon, Thomas; Nestorovski, Zoran

    2013-01-01

    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. PMID:24212308

  19. Rationale, Science, and Economics of Surgical Nerve Decompression for Diabetic Neuropathy Foot Complications.

    Science.gov (United States)

    Nickerson, David Scott

    2016-04-01

    Nerve decompression is effective and safe for dealing with the pain and numbness symptoms of the frequent nerve compression entrapments in diabetic symmetric peripheral neuropathy (DSPN). Evidence has accumulated of balance and stability improvements and protection against diabetic foot ulceration, recurrence and its complication cascade. Nerve decompression proffers significant benefit versus the large socioeconomic costs of DSPN complications. Advancing understanding of the mechanism of nerve compression and altered axonal activity in diabetes clarifies the basis of clinical benefit. Clinicians should seek out and recognize nerve entrapments and consider advising nerve decompression for relief of DSPN symptoms and prevention of complications. PMID:27013417

  20. 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.

  1. Genetics Home Reference: distal hereditary motor neuropathy, type V

    Science.gov (United States)

    ... neuropathy, type V distal hereditary motor neuropathy, type V Enable Javascript to view the expand/collapse boxes. ... Close All Description Distal hereditary motor neuropathy, type V is a progressive disorder that affects nerve cells ...

  2. Genetics Home Reference: hereditary sensory neuropathy type IA

    Science.gov (United States)

    ... Health Conditions hereditary sensory neuropathy type IA hereditary sensory neuropathy type IA Enable Javascript to view the ... Download PDF Open All Close All Description Hereditary sensory neuropathy type IA is a condition characterized by ...

  3. 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...

  4. 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...... 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...... in type 2 diabetes. CAN is a risk marker of mortality and cardiovascular morbidity, and possibly a progression promoter of diabetic nephropathy. Criteria for CAN diagnosis and staging are: 1. one abnormal cardio-vagal test identifies possible or early CAN; 2. at least two abnormal cardio-vagal tests...

  5. Treatment of gastrointestinal autonomic neuropathy.

    Science.gov (United States)

    Törnblom, Hans

    2016-03-01

    The symptoms caused by gastrointestinal autonomic neuropathy in diabetes mellitus is important to highlight since it affects a large proportion of people with diabetes, regardless of whether this is type 1 or type 2. Gastroparesis and general signs of bowel dysfunction, such as constipation, diarrhoea and abdominal pain are most often encountered and involve both pharmacological and non-pharmacological treatment options. This mini-review summarises a presentation given at the 'Diagnosis and treatment of autonomic diabetic neuropathy in the gut' symposium at the 2015 annual meeting of the EASD. It is accompanied by another mini-review on a topic from this symposium (by Azpiroz and Malagelada, DOI: 10.1007/s00125-015-3831-1 ) and a commentary by the Session Chair, Péter Kempler (DOI: 10.1007/s00125-015-3826-y ). PMID:26634570

  6. Uremic Neuropathy: Epiemiological Study in Hemodialysis Patients

    OpenAIRE

    Ricci, Davide

    2012-01-01

    Background/Aims. Uremic Neuropathy (UN) highly limits the individual self-sufficiency causing near-continuous pain. An estimation of the actual UN prevalence among hemodialysis patients was the aim of the present work. Methods. We studied 225 prevalent dialysis patients from two Italian Centres. The Michigan Neuropathy Score Instrument (MNSI), already validated in diabetic neuropathy, was used for the diagnosis of UN. It consisted of a questionnaire (MNSI_Q) and a physical-clinical evaluat...

  7. Dyslipidemia-Induced Neuropathy in Mice

    OpenAIRE

    Vincent, Andrea M.; Hayes, John M.; McLean, Lisa L.; Vivekanandan-Giri, Anuradha; Pennathur, Subramaniam; Eva L Feldman

    2009-01-01

    OBJECTIVE Neuropathy is a frequent and severe complication of diabetes. Multiple metabolic defects in type 2 diabetic patients result in oxidative injury of dorsal root ganglia (DRG) neurons. Our previous work focused on hyperglycemia clearly demonstrates induction of mitochondrial oxidative stress and acute injury in DRG neurons; however, this mechanism is not the only factor that produces neuropathy in vivo. Dyslipidemia also correlates with the development of neuropathy, even in pre-diabet...

  8. Treatment of chronic inflammatory neuropathies

    OpenAIRE

    Schaik, van, I.N.; Eftimov, F.

    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 intravenous immunoglobulin (IVIg) in CIDP and MMN was confirmed in meta-analyses. In CIDP, IVIg efficacy was similar to the efficacy of plasma exchange, prednisolone and intravenous methylprednisolone. ...

  9. Treatment of painful diabetic neuropathy

    OpenAIRE

    Javed, Saad; Petropoulos, Ioannis N.; Alam, Uazman; Malik, Rayaz A.

    2015-01-01

    Painful diabetic neuropathy (PDN) is a debilitating consequence of diabetes that may be present in as many as one in five patients with diabetes. The objective assessment of PDN is difficult, making it challenging to diagnose and assess in both clinical practice and clinical trials. No single treatment exists to prevent or reverse neuropathic changes or to provide total pain relief. Treatment of PDN is based on three major approaches: intensive glycaemic control and risk factor management, tr...

  10. Cranial Neuropathy in Multiple Sclerosis

    OpenAIRE

    Mine Hayriye Sorgun; Bilge Koçer; Funda Kaplan; Nesrin Yılmaz; Nezih Yücemen; Canan Yücesan

    2011-01-01

    OBJECTIVE: It has been reported that cranial neuropathy findings could be seen in the neurologic examination of multiple sclerosis (MS) patients, although brain magnetic resonance imaging (MRI) may not reveal any lesion responsible for the cranial nerve involvement. The aim of this study was to determine the frequency of brainstem and cranial nerve involvement, except for olfactory and optic nerves, during MS attacks, and to investigate the rate of an available explanation for the cranial neu...

  11. 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.

  12. 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.

  13. Imaging of neuropathies about the hip

    International Nuclear Information System (INIS)

    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

  14. 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

  15. 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...

  16. Sensory neuropathy in two Border collie puppies.

    Science.gov (United States)

    Vermeersch, K; Van Ham, L; Braund, K G; Bhatti, S; Tshamala, M; Chiers, K; Schrauwen, E

    2005-06-01

    A peripheral sensory neuropathy was diagnosed in two Border collie puppies. Neurological, electrophysiological and histopathological examinations suggested a purely sensory neuropathy with mainly distal involvement. Urinary incontinence was observed in one of the puppies and histological examination of the vagus nerve revealed degenerative changes. An inherited disorder was suspected. PMID:15971901

  17. 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

  18. 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. PMID:27594833

  19. 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.

  20. [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.

  1. 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

  2. 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...

  3. 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.

  4. MR imaging of trigeminal neuropathy

    International Nuclear Information System (INIS)

    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

  5. 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

  6. 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...

  7. 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

  8. 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.

  9. Neurofilament spacing, phosphorylation, and axon diameter in regenerating and uninjured lamprey axons.

    Science.gov (United States)

    Pijak, D S; Hall, G F; Tenicki, P J; Boulos, A S; Lurie, D I; Selzer, M E

    1996-05-13

    It has been postulated that phosphorylation of the carboxy terminus sidearms of neurofilaments (NFs) increases axon diameter through repulsive electrostatic forces that increase sidearm extension and interfilament spacing. To evaluate this hypothesis, the relationships among NF phosphorylation, NF spacing, and axon diameter were examined in uninjured and spinal cord-transected larval sea lampreys (Petromyzon marinus). In untransected animals, axon diameters in the spinal cord varied from 0.5 to 50 microns. Antibodies specific for highly phosphorylated NFs labeled only large axons (> 10 microns), whereas antibodies for lightly phosphorylated NFs labeled medium-sized and small axons more darkly than large axons. For most axons in untransected animals, diameter was inversely related to NF packing density, but the interfilament distances of the largest axons were only 1.5 times those of the smallest axons. In addition, the lightly phosphorylated NFs of the small axons in the dorsal columns were widely spaced, suggesting that phosphorylation of NFs does not rigidly determine their spacing and that NF spacing does not rigidly determine axon diameter. Regenerating neurites of giant reticulospinal axons (GRAs) have diameters only 5-10% of those of their parent axons. If axon caliber is controlled by NF phosphorylation via mutual electrostatic repulsion, then NFs in the slender regenerating neurites should be lightly phosphorylated and densely packed (similar to NFs in uninjured small caliber axons), whereas NFs in the parent GRAs should be highly phosphorylated and loosely packed. However, although linear density of NFs (the number of NFs per micrometer) in these slender regenerating neurites was twice that in their parent axons, they were highly phosphorylated. Following sectioning of these same axons close to the cell body, axon-like neurites regenerated ectopically from dendritic tips. These ectopically regenerating neurites had NF linear densities 2.5 times those of

  10. [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.

  11. 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. PMID:27439954

  12. Neuronal Development: SAD Kinases Make Happy Axons

    OpenAIRE

    Xing, Lei; Newbern, Jason M.; Snider, William D

    2013-01-01

    The polarity proteins LKB1 and SAD-A/B are key regulators of axon specification in the developing cerebral cortex. Recent studies now show that this mechanism cannot be generalized to other classes of neurons: instead, SAD-A/B functions downstream of neurotrophin signaling in sensory neurons to mediate a later stage of axon development — arborization in the target field.

  13. 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

  14. 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.

  15. 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. PMID:27439954

  16. The challenges of axon survival: introduction to the special issue on axonal degeneration.

    Science.gov (United States)

    Coleman, Michael P

    2013-08-01

    Early axon loss is a common feature of many neurodegenerative disorders. It renders neurons functionally inactive, or less active if axon branches are lost, in a manner that is often irreversible. In the CNS, there is no long-range axon regeneration and even peripheral nerve axons are unlikely to reinnervate their targets while the cause of the problem persists. In most disorders, axon degeneration precedes cell death so it is not simply a consequence of it, and it is now clear that axons have at least one degeneration mechanism that differs from that of the soma. It is important to understand these degeneration mechanisms and their contribution to axon loss in neurodegenerative disorders. In this way, it should become possible to prevent axon loss as well as cell death. This special edition considers the roles and mechanisms of axon degeneration in amyotrophic lateral sclerosis, Charcot-Marie-Tooth disease, hereditary spastic paraplegia, ischemic injury, traumatic brain injury, Alzheimer's disease, glaucoma, Huntington's disease and Parkinson's disease. Using examples from these and other disorders, this introduction considers some of the reasons for axon vulnerability. It also illustrates how molecular genetics and studies of Wallerian degeneration have contributed to our understanding of axon degeneration mechanisms. PMID:23769907

  17. 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.

  18. 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.

  19. Structural Basis for Induction of Peripheral Neuropathy by Microtubule-Targeting Cancer Drugs.

    Science.gov (United States)

    Smith, Jennifer A; Slusher, Barbara S; Wozniak, Krystyna M; Farah, Mohamed H; Smiyun, Gregoriy; Wilson, Leslie; Feinstein, Stuart; Jordan, Mary Ann

    2016-09-01

    Peripheral neuropathy is a serious, dose-limiting side effect of cancer treatment with microtubule-targeting drugs. Symptoms present in a "stocking-glove" distribution, with longest nerves affected most acutely, suggesting a length-dependent component to the toxicity. Axonal transport of ATP-producing mitochondria along neuronal microtubules from cell body to synapse is crucial to neuronal function. We compared the effects of the drugs paclitaxel and ixabepilone that bind along the lengths of microtubules and the drugs eribulin and vincristine that bind at microtubule ends, on mitochondrial trafficking in cultured human neuronal SK-N-SH cells and on axonal transport in mouse sciatic nerves. Antiproliferative concentrations of paclitaxel and ixabepilone significantly inhibited the anterograde transport velocity of mitochondria in neuronal cells, whereas eribulin and vincristine inhibited transport only at significantly higher concentrations. Confirming these observations, anterogradely transported amyloid precursor protein accumulated in ligated sciatic nerves of control and eribulin-treated mice, but not in paclitaxel-treated mice, indicating that paclitaxel inhibited anterograde axonal transport, whereas eribulin did not. Electron microscopy of sciatic nerves of paclitaxel-treated mice showed reduced organelle accumulation proximal to the ligation consistent with inhibition of anterograde (kinesin based) transport by paclitaxel. In contrast, none of the drugs significantly affected retrograde (dynein based) transport in neuronal cells or mouse nerves. Collectively, these results suggest that paclitaxel and ixabepilone, which bind along the lengths and stabilize microtubules, inhibit kinesin-based axonal transport, but not dynein-based transport, whereas the microtubule-destabilizing drugs, eribulin and vincristine, which bind preferentially to microtubule ends, have significantly less effect on all microtubule-based axonal transport. Cancer Res; 76(17); 5115-23.

  20. 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.

  1. Dynamics of Mitochondrial Transport in Axons.

    Science.gov (United States)

    Niescier, Robert F; Kwak, Sang Kyu; Joo, Se Hun; Chang, Karen T; Min, Kyung-Tai

    2016-01-01

    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. PMID:27242435

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Phenotyping animal models of diabetic neuropathy

    DEFF Research Database (Denmark)

    Biessels, G J; Bril, V; Calcutt, N A;

    2014-01-01

    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...... 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...... toward the therapeutic efficacy of drug interventions....

  7. 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.

  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 Dy(2j/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. Peptide mimetic of the S100A4 protein modulates peripheral nerve regeneration and attenuates the progression of neuropathy in myelin protein P0 null mice

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Pinchenko, Volodymyr; Dmytriyeva, Oksana;

    2013-01-01

    We recently found that S100A4, a member of the multifunctional S100 protein family, protects neurons in the injured brain and identified two sequence motifs in S100A4 mediating its neurotrophic effect. Synthetic peptides encompassing these motifs stimulated neuritogenesis and survival in vitro an......, such as Charcot-Marie-Tooth type 1 disease. Moreover, our data suggest that S100A4 is a neuroprotectant in PNS and that other S100 proteins, sharing high homology in the H3 motif, may have important functions in PNS pathologies......., these effects were attributed to the modulatory effect of H3 on initial axonal sprouting. In contrast to the modest effect of H3 on the time course of regeneration, H3 had a long-term neuroprotective effect in the myelin protein P0 null mice, a model of dysmyelinating neuropathy (Charcot-Marie-Tooth type 1...... disease), where the peptide attenuated the deterioration of nerve conduction, demyelination and axonal loss. From these results, S100A4 mimetics emerge as a possible means to enhance axonal sprouting and survival, especially in the context of demyelinating neuropathies with secondary axonal loss...

  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. 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.

  12. Sildenafil ameliorates long term peripheral neuropathy in type II diabetic mice.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Diabetic peripheral neuropathy is a common complication of long-standing diabetes mellitus. To mimic clinical trials in which patients with diabetes enrolled have advanced peripheral neuropathy, we investigated the effect of sildenafil, a specific inhibitor of phosphodiesterase type 5 enzyme, on long term peripheral neuropathy in middle aged male mice with type II diabetes. Treatment of diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db at age 36 weeks with sildenafil significantly increased functional blood vessels and regional blood flow in the sciatic nerve, concurrently with augmentation of intra-epidermal nerve fiber density in the skin and myelinated axons in the sciatic nerve. Functional analysis showed that the sildenafil treatment considerably improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal stimulus sensitivity compared with the saline treatment. In vitro studies showed that mouse dermal endothelial cells (MDE cultured under high glucose levels exhibited significant down regulation of angiopoietin 1 (Ang1 expression and reduction of capillary-like tube formation, which were completely reversed by sildenafil. In addition, incubation of dorsal root ganglia (DRG neurons with conditioned medium harvested from MDE under high glucose levels suppressed neurite outgrowth, where as conditional medium harvested from MDE treated with sildenafil under high glucose levels did not inhibit neurite outgrowth of DRG neurons. Moreover, blockage of the Ang1 receptor, Tie2, with a neutralized antibody against Tie2 abolished the beneficial effect of sildenafil on tube formation and neurite outgrowth. Collectively, our data indicate that sildenafil has a therapeutic effect on long term peripheral neuropathy of middle aged diabetic mice and that improvement of neurovascular dysfunction by sildenafil likely contributes to the amelioration of nerve function. The Ang1/Tie2 signaling pathway may play an important role in these

  13. Infectious optic neuropathies: a clinical update

    Directory of Open Access Journals (Sweden)

    Kahloun R

    2015-09-01

    Full Text Available Rim Kahloun, Nesrine Abroug, Imen Ksiaa, Anis Mahmoud, Hatem Zeghidi, Sonia Zaouali, Moncef KhairallahDepartment of Ophthalmology, Fattouma Bourguiba University Hospital, Faculty of Medicine, University of Monastir, Monastir, TunisiaAbstract: 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.Keywords: optic neuropathy, viruses, bacteria, parasites, fungi, vaccination

  14. Bicycling induced pudendal nerve pressure neuropathy.

    Science.gov (United States)

    Silbert, P L; Dunne, J W; Edis, R H; Stewart-Wynne, E G

    1991-01-01

    Pudendal neuropathies are well recognised as part of more generalised peripheral neuropathies; however, focal abnormalities of the pudendal nerve due to cycling-related injuries have been infrequently reported. We describe two patients who developed pudendal neuropathies secondary to pressure effects on the perineum from racing-bicycle saddles. Both were male competitive athletes, one of whom developed recurrent numbness of the penis and scrotum after prolonged cycling; the other developed numbness of the penis, an altered sensation of ejaculation, with disturbance of micturition and reduced awareness of defecation. Both patients improved with alterations in saddle position and riding techniques. We conclude that pudendal nerve pressure neuropathy can result from prolonged cycling, particularly when using a poor riding technique. PMID:1821826

  15. 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

  16. [Peripheral neuropathy caused by acute arsenic poisoning].

    Science.gov (United States)

    Ramírez-Campos, J; Ramos-Peek, J; Martínez-Barros, M; Zamora-Peralta, M; Martínez-Cerrato, J

    1998-01-01

    Although peripheral neuropathy is a fairly common finding in chronic arsenic poisoning, little is known about the acute effects of this metal on peripheral nerves. This report shows clinical and electrophysiological findings in a patient who developed peripheral neuropathy only three days after a high-dose ingestion of this metal due to a failed suicide attempt. We speculate that peripheral nerves and some cranial nerves can show not only clinical but also subclinical involvement that can only be detected by neurophysiological studies.

  17. Multiple cranial neuropathies following etanercept administration.

    Science.gov (United States)

    Hunter, Jacob B; Rivas, Alejandro

    2016-01-01

    There have been recent reports of sarcoid-like granulomatosis development following the administration of tumor necrosis factor (TNF) inhibitors. To date, only four cases of neurosarcoidosis have been reported in association with TNF inhibitors, two of which were attributed to etanercept. We present the first case of etanercept-induced neurosarcoidosis involving multiple cranial neuropathies, including the trigeminal, facial, and vestibulocochlear nerves, while also highlighting the differential diagnoses of multiple cranial neuropathies and the association of TNF inhibitors and neurosarcoidosis. PMID:27178520

  18. 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.

  19. 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

  20. 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

  1. Treatment of painful diabetic neuropathy.

    Science.gov (United States)

    Javed, Saad; Petropoulos, Ioannis N; Alam, Uazman; Malik, Rayaz A

    2015-01-01

    Painful diabetic neuropathy (PDN) is a debilitating consequence of diabetes that may be present in as many as one in five patients with diabetes. The objective assessment of PDN is difficult, making it challenging to diagnose and assess in both clinical practice and clinical trials. No single treatment exists to prevent or reverse neuropathic changes or to provide total pain relief. Treatment of PDN is based on three major approaches: intensive glycaemic control and risk factor management, treatments based on pathogenetic mechanisms, and symptomatic pain management. Clinical guidelines recommend pain relief in PDN through the use of antidepressants such as amitriptyline and duloxetine, the γ-aminobutyric acid analogues gabapentin and pregabalin, opioids and topical agents such as capsaicin. Of these medications, duloxetine and pregabalin were approved by the US Food and Drug Administration (FDA) in 2004 and tapentadol extended release was approved in 2012 for the treatment of PDN. Proposed pathogenetic treatments include α-lipoic acid (stems reactive oxygen species formation), benfotiamine (prevents vascular damage in diabetes) and aldose-reductase inhibitors (reduces flux through the polyol pathway). There is a growing need for studies to evaluate the most potent drugs or combinations for the management of PDN to maximize pain relief and improve quality of life. A number of agents are potential candidates for future use in PDN therapy, including Nav 1.7 antagonists, N-type calcium channel blockers, NGF antibodies and angiotensin II type 2 receptor antagonists. PMID:25553239

  2. [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).

  3. Prolyl Isomerase Pin1 Regulates Axon Guidance by Stabilizing CRMP2A Selectively in Distal Axons

    Directory of Open Access Journals (Sweden)

    Martin Balastik

    2015-10-01

    Full Text Available Axon guidance relies on precise translation of extracellular signal gradients into local changes in cytoskeletal dynamics, but the molecular mechanisms regulating dose-dependent responses of growth cones are still poorly understood. Here, we show that during embryonic development in growing axons, a low level of Semaphorin3A stimulation is buffered by the prolyl isomerase Pin1. We demonstrate that Pin1 stabilizes CDK5-phosphorylated CRMP2A, the major isoform of CRMP2 in distal axons. Consequently, Pin1 knockdown or knockout reduces CRMP2A levels specifically in distal axons and inhibits axon growth, which can be fully rescued by Pin1 or CRMP2A expression. Moreover, Pin1 knockdown or knockout increases sensitivity to Sema3A-induced growth cone collapse in vitro and in vivo, leading to developmental abnormalities in axon guidance. These results identify an important isoform-specific function and regulation of CRMP2A in controlling axon growth and uncover Pin1-catalyzed prolyl isomerization as a regulatory mechanism in axon guidance.

  4. [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.

  5. Genetics Home Reference: neuropathy, ataxia, and retinitis pigmentosa

    Science.gov (United States)

    ... Me Understand Genetics Home Health Conditions NARP neuropathy, ataxia, and retinitis pigmentosa Enable Javascript to view the ... Download PDF Open All Close All Description Neuropathy, ataxia, and retinitis pigmentosa ( NARP ) is a condition that ...

  6. Ischemic neuropathy and rhabdomyolysis as presenting symptoms of postpartum cardiomyopathy.

    NARCIS (Netherlands)

    Helmich, R.C.G.; Laarhoven, H.W.M. van; Schoonderwaldt, H.C.; Janssen, M.C.H.

    2009-01-01

    Rhabdomyolysis and peripheral neuropathy are two distinct disease entities which are rarely encountered in combination. We present a woman with rhabdomyolysis and peripheral neuropathy 3 weeks postpartum. Her symptoms were caused by bilateral femoral artery thrombosis due to postpartum cardiomyopath

  7. DIABETIC NEUROPATHY PART 2: PROXIMAL AND ASSYMMETRIC PHENOTYPES

    OpenAIRE

    Pasnoor, Mamatha; Dimachkie, Mazen M.; Barohn, Richard J.

    2013-01-01

    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 n...

  8. Health State Preference Assessment in Diabetic Peripheral Neuropathy

    OpenAIRE

    Sullivan, Sean D.; Doris P. Lew; E. Beth Devine; Zafar Hakim; Gayle E. Reiber; Veenstra, David L.

    2002-01-01

    Objective: To assess patient preferences for health states associated with diabetic peripheral neuropathy (DPN). Design and intervention: Seven health states describing varying stages of disease severity in DPN were developed: mild neuropathy, painful neuropathy, severe neuropathy, minor ulcer, severe ulcer, minor amputation and major amputation. Using a computer interview, both rating scale (RS) and standard gamble (SG) preference scores were elicited from 52 patients with diabetes mellitus....

  9. Animal Models of Peripheral Neuropathy Due to Environmental Toxicants

    OpenAIRE

    Rao, Deepa B.; Jortner, Bernard S.; Sills, Robert C.

    2014-01-01

    Despite the progress in our understanding of pathogeneses and the identification of etiologies of peripheral neuropathy, idiopathic neuropathy remains common. Typically, attention to peripheral neuropathies resulting from exposure to environmental agents is limited relative to more commonly diagnosed causes of peripheral neuropathy (diabetes and chemotherapeutic agents). Given that there are more than 80,000 chemicals in commerce registered with the Environmental Protection Agency and that at...

  10. 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.

  11. 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.

  12. Blood pressure regulation in diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1985-01-01

    Defective blood pressure responses to standing, exercise and epinephrine infusions have been demonstrated in diabetic patients with autonomic neuropathy. The circulatory mechanisms underlying blood pressure responses to exercise and standing up in these patients are well characterized: In both...... 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...... which may contribute to exercise hypotension in these patients. During hypoglycemia, blood pressure regulation seems intact in patients with autonomic neuropathy. This is probably due to release of substantial amounts of catecholamines during these experiments. During epinephrine infusions a substantial...

  13. 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.

  14. 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.

  15. [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).

  16. Microfluidic device for unidirectional axon growth

    Science.gov (United States)

    Malishev, E.; Pimashkin, A.; Gladkov, A.; Pigareva, Y.; Bukatin, A.; Kazantsev, V.; Mukhina, I.; Dubina, M.

    2015-11-01

    In order to better understand the communication and connectivity development of neuron networks, we designed microfluidic devices with several chambers for growing dissociated neuronal cultures from mice fetal hippocampus (E18). The chambers were connected with microchannels providing unidirectional axonal growth between “Source” and “Target” neural sub-networks. Experiments were performed in a hippocampal cultures plated in a poly-dimethylsiloxane (PDMS) microfluidic chip, aligned with a 60 microelectrode array (MEA). Axonal growth through microchannels was observed with brightfield, phase-contrast and fluorescence microscopy, and after 7 days in vitro electrical activity was recorded. Visual inspection and spike propagation analysis showed the predominant axonal growth in microchannels in a direction from “Source” to “Target”.

  17. 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.

  18. 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.

  19. Diagnosis and therapeutic options for peripheral vasculitic neuropathy.

    Science.gov (United States)

    Blaes, Franz

    2015-04-01

    Vasculitis can affect the peripheral nervous system alone (nonsystemic vasculitic neuropathy) or can be a part of primary or secondary systemic vasculitis. In cases of pre-existing systemic vasculitis, the diagnosis can easily be made, whereas suspected vasculitic neuropathy as initial or only manifestation of vasculitis requires careful clinical, neurophysiological, laboratory and histopathological workout. The typical clinical syndrome is mononeuropathia multiplex or asymmetric neuropathy, but distal-symmetric neuropathy can frequently be seen. Standard treatments include steroids, azathioprine, methotrexate and cyclophosphamide. More recently the B-cell antibody rituximab and intravenous immunoglobulins have shown to be effective in some vasculitic neuropathy types. PMID:25829955

  20. 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...

  1. 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

  2. [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.

  3. Assessment of diabetic peripheral neuropathy in streptozotocin-induced diabetic rats with magnetic resonance imaging

    International Nuclear Information System (INIS)

    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.)

  4. Metabolic Dysfunction Is Restricted to the Sciatic Nerve in Experimental Diabetic Neuropathy.

    Science.gov (United States)

    Freeman, Oliver J; Unwin, Richard D; Dowsey, Andrew W; Begley, Paul; Ali, Sumia; Hollywood, Katherine A; Rustogi, Nitin; Petersen, Rasmus S; Dunn, Warwick B; Cooper, Garth J S; Gardiner, Natalie J

    2016-01-01

    High glucose levels in the peripheral nervous system (PNS) have been implicated in the pathogenesis of diabetic neuropathy (DN). However, our understanding of the molecular mechanisms that cause the marked distal pathology is incomplete. We performed a comprehensive, system-wide analysis of the PNS of a rodent model of DN. We integrated proteomics and metabolomics from the sciatic nerve (SN), the lumbar 4/5 dorsal root ganglia (DRG), and the trigeminal ganglia (TG) of streptozotocin-diabetic and healthy control rats. Even though all tissues showed a dramatic increase in glucose and polyol pathway intermediates in diabetes, a striking upregulation of mitochondrial oxidative phosphorylation and perturbation of lipid metabolism was found in the distal SN that was not present in the corresponding cell bodies of the DRG or the cranial TG. This finding suggests that the most severe molecular consequences of diabetes in the nervous system present in the SN, the region most affected by neuropathy. Such spatial metabolic dysfunction suggests a failure of energy homeostasis and/or oxidative stress, specifically in the distal axon/Schwann cell-rich SN. These data provide a detailed molecular description of the distinct compartmental effects of diabetes on the PNS that could underlie the distal-proximal distribution of pathology. PMID:26470786

  5. 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. PMID:26370700

  6. 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.)

  7. 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.

  8. 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.

  9. 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.

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

    OpenAIRE

    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 symmetri...

  12. Late onset Leber's optic neuropathy: a case confused with ischaemic optic neuropathy.

    OpenAIRE

    Borruat, F X; Green, W T; Graham, E M; Sweeney, M G.; Morgan-Hughes, J A; Sanders, M D

    1992-01-01

    A case is reported of a 63-year-old man with progressive central visual loss in one eye followed 11 months later by involvement of the fellow eye. A diagnosis of chronic ischaemic optic neuropathy was considered. However, despite a negative family history, the absence of electrocardiographic abnormalities, and minimal fundus changes a diagnosis of Leber's optic neuropathy was made on the basis of magnetic resonance imaging findings and the mitochondrial DNA mutation at base pair 11778.

  13. 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.

  14. 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

  15. 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.

  16. Poisoning by organophosphorus insecticides and sensory neuropathy

    OpenAIRE

    Moretto, A; M. Lotti

    1998-01-01

    OBJECTIVES—Poisoning by organophosphate insecticides causes cholinergic toxicity. Organophosphate induced delayed polyneuropathy (OPIDP) is a sensory-motor distal axonopathy which usually occurs after ingestion of large doses of certain organophosphate insecticides and has so far only been reported in patients with preceding cholinergic toxicity. Surprisingly, it was recently reported by other authors that an exclusively sensory neuropathy developed in eight patients afte...

  17. Idiopathic trigeminal neuropathy in a poodle

    Directory of Open Access Journals (Sweden)

    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.

  18. 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...

  19. [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

  20. 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.

  1. MRI in Leber's hereditary optic neuropathy

    DEFF Research Database (Denmark)

    Matthews, Lucy; Enzinger, Christian; Fazekas, Franz;

    2015-01-01

    BACKGROUND: Leber's hereditary optic neuropathy (LHON) and a multiple sclerosis (MS)-like illness appear to coexist 50 times more frequently than would be expected by chance. This association of LHON and MS (LMS) raises an important question about whether there could be a common pathophysiological...

  2. Functions of axon guidance molecules in synapse formation

    OpenAIRE

    Chen, Shih-Yu; Cheng, Hwai-Jong

    2009-01-01

    Axon guidance and synapse formation are important developmental events for establishing a functional neuronal circuitry. These two related cellular processes occur in a coordinated fashion but previous studies from multiple model organisms seemed to suggest that axon guidance and synapse formation are mediated by distinct molecular cues. Thus, axon guidance molecules are responsible for guiding the navigating axon toward its target area, while other adhesion or ligand-receptor molecules speci...

  3. 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.

  4. Electrokinetic confinement of axonal growth for dynamically configurable neural networks.

    Science.gov (United States)

    Honegger, Thibault; Scott, Mark A; Yanik, Mehmet F; Voldman, Joel

    2013-02-21

    Axons in the developing nervous system are directed via guidance cues, whose expression varies both spatially and temporally, to create functional neural circuits. Existing methods to create patterns of neural connectivity in vitro use only static geometries, and are unable to dynamically alter the guidance cues imparted on the cells. We introduce the use of AC electrokinetics to dynamically control axonal growth in cultured rat hippocampal neurons. We find that the application of modest voltages at frequencies on the order of 10(5) Hz can cause developing axons to be stopped adjacent to the electrodes while axons away from the electric fields exhibit uninhibited growth. By switching electrodes on or off, we can reversibly inhibit or permit axon passage across the electrodes. Our models suggest that dielectrophoresis is the causative AC electrokinetic effect. We make use of our dynamic control over axon elongation to create an axon-diode via an axon-lock system that consists of a pair of electrode 'gates' that either permit or prevent axons from passing through. Finally, we developed a neural circuit consisting of three populations of neurons, separated by three axon-locks to demonstrate the assembly of a functional, engineered neural network. Action potential recordings demonstrate that the AC electrokinetic effect does not harm axons, and Ca(2+) imaging demonstrated the unidirectional nature of the synaptic connections. AC electrokinetic confinement of axonal growth has potential for creating configurable, directional neural networks. PMID:23314575

  5. 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.

  6. 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.

  7. Spatial temperature gradients guide axonal outgrowth

    Science.gov (United States)

    Black, Bryan; Vishwakarma, Vivek; Dhakal, Kamal; Bhattarai, Samik; Pradhan, Prabhakar; Jain, Ankur; Kim, Young-Tae; Mohanty, Samarendra

    2016-07-01

    Formation of neural networks during development and regeneration after injury depends on accuracy of axonal pathfinding, which is primarily believed to be influenced by chemical cues. Recently, there is growing evidence that physical cues can play crucial role in axonal guidance. However, detailed mechanism involved in such guidance cues is lacking. By using weakly-focused near-infrared continuous wave (CW) laser microbeam in the path of an advancing axon, we discovered that the beam acts as a repulsive guidance cue. Here, we report that this highly-effective at-a-distance guidance is the result of a temperature field produced by the near-infrared laser light absorption. Since light absorption by extracellular medium increases when the laser wavelength was red shifted, the threshold laser power for reliable guidance was significantly lower in the near-infrared as compared to the visible spectrum. The spatial temperature gradient caused by the near-infrared laser beam at-a-distance was found to activate temperature-sensitive membrane receptors, resulting in an influx of calcium. The repulsive guidance effect was significantly reduced when extracellular calcium was depleted or in the presence of TRPV1-antagonist. Further, direct heating using micro-heater confirmed that the axonal guidance is caused by shallow temperature-gradient, eliminating the role of any non-photothermal effects.

  8. Axonal PPARγ promotes neuronal regeneration after injury.

    Science.gov (United States)

    Lezana, Juan Pablo; Dagan, Shachar Y; Robinson, Ari; Goldstein, Ronald S; Fainzilber, Mike; Bronfman, Francisca C; Bronfman, Miguel

    2016-06-01

    PPARγ is a ligand-activated nuclear receptor best known for its involvement in adipogenesis and glucose homeostasis. PPARγ activity has also been associated with neuroprotection in different neurological disorders, but the mechanisms involved in PPARγ effects in the nervous system are still unknown. Here we describe a new functional role for PPARγ in neuronal responses to injury. We found both PPAR transcripts and protein within sensory axons and observed an increase in PPARγ protein levels after sciatic nerve crush. This was correlated with increased retrograde transport of PPARγ after injury, increased association of PPARγ with the molecular motor dynein, and increased nuclear accumulation of PPARγ in cell bodies of sensory neurons. Furthermore, PPARγ antagonists attenuated the response of sensory neurons to sciatic nerve injury, and inhibited axonal growth of both sensory and cortical neurons in culture. Thus, axonal PPARγ is involved in neuronal injury responses required for axonal regeneration. Since PPARγ is a major molecular target of the thiazolidinedione (TZD) class of drugs used in the treatment of type II diabetes, several pharmaceutical agents with acceptable safety profiles in humans are available. Our findings provide motivation and rationale for the evaluation of such agents for efficacy in central and peripheral nerve injuries. PMID:26446277

  9. 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.

  10. Patterns of growth, axonal extension and axonal arborization of neuronal lineages in the developing Drosophila brain

    OpenAIRE

    Larsen, Camilla; Shy, Diana; Spindler, Shana R; Fung, Siaumin; Pereanu, Wayne; Younossi -Hartenstein, Amelia; Hartenstein, Volker

    2009-01-01

    The Drosophila central brain is composed of approximately 100 paired lineages, with most lineages comprising 100–150 neurons. Most lineages have a number of important characteristics in common. Typically, neurons of a lineage stay together as a coherent cluster and project their axons into a coherent bundle visible from late embryo to adult. Neurons born during the embryonic period form the primary axon tracts (PATs) that follow stereotyped pathways in the neuropile. Apoptotic cell death remo...

  11. 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.

  12. 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

  13. Mislocalization of neuronal mitochondria reveals regulation of Wallerian degeneration and NMNAT/WLDS-mediated axon protection independent of axonal mitochondria

    OpenAIRE

    Kitay, Brandon M.; McCormack, Ryan; Wang, Yunfang; Tsoulfas, Pantelis; Zhai, R. Grace

    2013-01-01

    Axon degeneration is a common and often early feature of neurodegeneration that correlates with the clinical manifestations and progression of neurological disease. Nicotinamide mononucleotide adenylytransferase (NMNAT) is a neuroprotective factor that delays axon degeneration following injury and in models of neurodegenerative diseases suggesting a converging molecular pathway of axon self-destruction. The underlying mechanisms have been under intense investigation and recent reports suggest...

  14. 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.

  15. Dynamic Axonal Translation in Developing and Mature Visual Circuits.

    Science.gov (United States)

    Shigeoka, Toshiaki; Jung, Hosung; Jung, Jane; Turner-Bridger, Benita; Ohk, Jiyeon; Lin, Julie Qiaojin; Amieux, Paul S; Holt, Christine E

    2016-06-30

    Local mRNA translation mediates the adaptive responses of axons to extrinsic signals, but direct evidence that it occurs in mammalian CNS axons in vivo is scant. We developed an axon-TRAP-RiboTag approach in mouse that allows deep-sequencing analysis of ribosome-bound mRNAs in the retinal ganglion cell axons of the developing and adult retinotectal projection in vivo. The embryonic-to-postnatal axonal translatome comprises an evolving subset of enriched genes with axon-specific roles, suggesting distinct steps in axon wiring, such as elongation, pruning, and synaptogenesis. Adult axons, remarkably, have a complex translatome with strong links to axon survival, neurotransmission, and neurodegenerative disease. Translationally co-regulated mRNA subsets share common upstream regulators, and sequence elements generated by alternative splicing promote axonal mRNA translation. Our results indicate that intricate regulation of compartment-specific mRNA translation in mammalian CNS axons supports the formation and maintenance of neural circuits in vivo. PMID:27321671

  16. 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.

  17. 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.

  18. Axons of sacral preganglionic neurons in the cat: II. Axon collaterals.

    Science.gov (United States)

    Morgan, C W

    2001-01-01

    Axon collaterals were identified in 21 of 24 preganglionic neurons in the lateral band of the sacral parasympathetic nucleus of the cat. Following the intracellular injection of HRP or neurobiotin the axons from 20 of these neurons were followed and 53 primary axon collaterals were found to originate from unmyelinated segments and from nodes of Ranvier. Detailed mapping done in the five best labeled cells showed bilateral axon collaterals distributions up to 25,000 microm in length with 950 varicosities and unilateral distributions up to 12,561 microm with 491 varicosities. The axon collaterals appeared to be unmyelinated, which was confirmed at EM, and were small in diameter (average 0.3 microm). Varicosities were located mostly in laminae I, V, VII, VIII and X and in the lateral funiculi. Most varicosities were not in contact with visible structures but some were seen in close apposition to Nissl stained somata and proximal dendrites. Varicosities had average minor diameters of 1.3 microm and major diameters of 2.3 microm. Most were boutons en passant while 10-20% were boutons termineaux. EM revealed axodendritic and axoaxonic synapses formed by varicosities and by the axons between varicosities. It is estimated that the most extensive of these axon collaterals systems may contact over 200 spinal neurons in multiple locations. These data lead to the conclusion that sacral preganglionic neurons have multiple functions within the spinal cord in addition to serving their target organ. As most preganglionic neurons in this location innervate the urinary bladder, it is possible that bladder preganglionic neurons have multiple functions.

  19. Surgical approach to lower extremity nerve decompression in the patient with diabetic neuropathy

    NARCIS (Netherlands)

    Dellon, A.L.

    2007-01-01

    Neuropathy associated with Diabetes is increasing at epidemic rates throughout the world. Traditionally, this neuropathy causes loss of protective sensation leading to ulceration, infection , and amputation. Even with good glycemic control, this neuropathy is still considered progressive and irrever

  20. Tumefactive Brain Demyelination Accompanying MADSAM Neuropathy

    Directory of Open Access Journals (Sweden)

    Şefik Evren Erdener

    2015-09-01

    Full Text Available Multifocal acquired demyelinating sensory and motor (MADSAM neuropathy is characterized by asymmetric multifocal motor and sensory loss and conduction blocks in peripheral nerves. Peripheral demyelinating diseases may be accompanied by demyelination in central nervous system (CNS. In this report, a MADSAM patient with a solitary tumefactive demyelinating lesion in brain is presented. Neuroimaging due to a visual field defect revealed a right parietooccipital lesion, which was initially misdiagnosed as a tumor. Pathological examination showed that it was demyelinating in nature. Peripheral nervous symptoms of the patient developed two years later and she was then diagnosed with MADSAM. There was prominent clinical and electrophysiological response to steroid treatment. Tumefactive brain involvement was not previously reported for MADSAM neuropathy, although it was documented in a single case with typical chronic inflammatory demyelinating polyneuropathy (CIDP. CNS involvement should therefore be considered in MADSAM patients.

  1. Cardiovascular autonomic neuropathy in the diabetic patients.

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Niño Mantilla

    2007-11-01

    Full Text Available the dysfunction of the autonomic nervous system is a serious problem in diabetic patients. The cardiovacular autonomic neuropathy is the most important autonomic dysfuntion for it´s implication in the increasesof the mortality rate in diabetis patients. tis ethiopatogenesis is the result of a multifactorial process caused by chronic hyperglycemia, ending up in damage of the autonomic fibers thet innervate the heart and blood vessels, leading to dysfuntional hearth rate control and abnormal vascular dynamics. the associated clinical manifestations include orthotatic hypotension, excecise intolerance, intraoperative cardiovascular liability and silent myocardial ischemia. Being important its recognition, quantitative test to evaluate the cardiovascular funtion, to value its evolution and the effects of the treatment ahould be done, being the most used, the hearth rate response to standing test, and teh valsalva maneuver. the handling of this entity is done improving control of glucose blood levels its the most effective way to prevent the cardiovascular autonomic neuropathy in the diabetic patients.

  2. Optic neuropathy in a patient with pyruvate dehydrogenase deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Small, Juan E. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Gonzalez, Guido E. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States); Clinica Alemana de Santiago, Departmento de Imagenes, Santiago (Chile); Nagao, Karina E.; Walton, David S. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Ophthalmology, Boston, MA (United States); Caruso, Paul A. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2009-10-15

    Pyruvate dehydrogenase (PDH) deficiency is a genetic disorder of mitochondrial metabolism. The clinical manifestations range from severe neonatal lactic acidosis to chronic neurodegeneration. Optic neuropathy is an uncommon clinical sequela and the imaging findings of optic neuropathy in these patients have not previously been described. We present a patient with PDH deficiency with bilateral decreased vision in whom MRI demonstrated bilateral optic neuropathy and chiasmopathy. (orig.)

  3. Auditory Neuropathy Spectrum Disorder Masquerading as Social Anxiety

    OpenAIRE

    Behere, Rishikesh V.; Rao, Mukund G.; Mishra, Shree; Varambally, Shivarama; Nagarajarao, Shivashankar; Bangalore N Gangadhar

    2015-01-01

    The authors report a case of a 47-year-old man who presented with treatment-resistant anxiety disorder. Behavioral observation raised clinical suspicion of auditory neuropathy spectrum disorder. The presence of auditory neuropathy spectrum disorder was confirmed on audiological investigations. The patient was experiencing extreme symptoms of anxiety, which initially masked the underlying diagnosis of auditory neuropathy spectrum disorder. Challenges in diagnosis and treatment of auditory neur...

  4. Diagnosis and therapeutic options for peripheral vasculitic neuropathy

    OpenAIRE

    Blaes, Franz

    2015-01-01

    Vasculitis can affect the peripheral nervous system alone (nonsystemic vasculitic neuropathy) or can be a part of primary or secondary systemic vasculitis. In cases of pre-existing systemic vasculitis, the diagnosis can easily be made, whereas suspected vasculitic neuropathy as initial or only manifestation of vasculitis requires careful clinical, neurophysiological, laboratory and histopathological workout. The typical clinical syndrome is mononeuropathia multiplex or asymmetric neuropathy, ...

  5. North America and South America (NA-SA) neuropathy project.

    Science.gov (United States)

    Pasnoor, Mamatha; Nascimento, Osvaldo J M; Trivedi, Jaya; Wolfe, Gil I; Nations, Sharon; Herbelin, Laura; de Freitas, M G; Quintanilha, Giseli; Khan, Saud; Dimachkie, Mazen; Barohn, Richard

    2013-08-01

    Peripheral neuropathy is a common neurological disorder. There may be important differences and similarities in the diagnosis of peripheral neuropathy between North America (NA) and South America (SA). Neuromuscular databases were searched for neuropathy diagnosis at two North American sites, University of Kansas Medical Center and University of Texas Southwestern Medical Center, and one South American site, Federal Fluminense University in Brazil. All patients were included into one of the six major categories: immune-mediated, diabetic, hereditary, infectious/inflammatory, systemic/metabolic/toxic (not diabetic) and cryptogenic. A comparison of the number of patients in each category was made between North America and South America databases. Total number of cases in North America was 1090 and in South America was 1034 [immune-mediated: NA 215 (19.7%), SA 191 (18%); diabetic: NA 148 (13.5%), SA 236 (23%); hereditary: NA 292 (26.7%), SA 103 (10%); infectious/inflammatory: NA 53 (4.8%), SA 141 (14%); systemic/metabolic/toxic: NA 71 (6.5%), SA 124 (12%); cryptogenic: NA 311 (28.5%), SA 239 (23%)]. Some specific neuropathy comparisons were hereditary neuropathies [Charcot-Marie-Tooth (CMT) cases] in NA 246/292 (84.2%) and SA 60/103 (58%); familial amyloid neuropathy in SA 31/103 (30%) and none in NA. Among infectious neuropathies, cases of human T-lymphotropic virus type 1 (HTLV-1) neuropathy in SA were 36/141(25%), Chagas disease in SA were 13/141(9%) and none for either in NA; cases of neuropathy due to leprosy in NA were 26/53 (49%) and in SA were 39/141(28%). South American tertiary care centers are more likely to see patients with infectious, diabetic and hereditary disorders such as familial amyloid neuropathies. North American tertiary centers are more likely to see patients with CMT. Immune neuropathies and cryptogenic neuropathies were seen equally in North America and South America.

  6. Infectious optic neuropathies: a clinical update

    OpenAIRE

    Kahloun R; Abroug N; Ksiaa I; Mahmoud A; Zeghidi H; Zaouali S; Khairallah M

    2015-01-01

    Rim Kahloun, Nesrine Abroug, Imen Ksiaa, Anis Mahmoud, Hatem Zeghidi, Sonia Zaouali, Moncef KhairallahDepartment of Ophthalmology, Fattouma Bourguiba University Hospital, Faculty of Medicine, University of Monastir, Monastir, TunisiaAbstract: 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...

  7. Leber hereditary optic neuropathy: current perspectives

    Directory of Open Access Journals (Sweden)

    Meyerson C

    2015-06-01

    Full Text Available Cherise Meyerson, Greg Van Stavern, Collin McClelland Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO, USA Abstract: Leber hereditary optic neuropathy (LHON is one of the most common inherited optic neuropathies causing bilateral central vision loss. The disorder results from point mutations in mitochondrial DNA and subsequent mitochondrial dysfunction. The primary cell type that is lost in LHON is the retinal ganglion cell, which is highly susceptible to disrupted ATP production and oxidative stress. Inheritance of LHON follows that of mitochondrial genetics, and it has a highly variable clinical phenotype, as other genetic and environmental factors also play a role. Although LHON usually presents with isolated vision loss, some patients suffer other neurological sequelae. For ill-defined reasons, male LHON mutation carriers are more affected than females. Most LHON patients remain legally blind, but a small proportion can experience spontaneous partial recovery, often within the first year of symptom onset. Unfortunately, at this time there are no established curative interventions and treatment is largely supportive. Patients should be offered low vision services and counseled on mitigating risk factors for additional vision loss, such as smoking and consuming alcohol. Encouraging treatments currently undergoing investigation includes ubiquinone analogs, such as idebenone, as well as gene therapy and stem cells to restore ATP synthesis and provide neuroprotection to surviving retinal ganglion cells. Keywords: Leber hereditary optic neuropathy, mitochondria, neuro-ophthalmology, mitochondrial DNA

  8. 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".

  9. 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.

  10. 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.

  11. Diabetic neuropathy part 2: proximal and asymmetric phenotypes.

    Science.gov (United States)

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

    2013-05-01

    Diabetic neuropathies consist of a variety of syndromes resulting from different types of damage to peripheral or cranial nerves. Although distal symmetric polyneuropathy is the most common type of diabetic neuropathy, many other subtypes have been defined since the 1800s, including proximal diabetic, truncal, cranial, median, and ulnar neuropathies. Various theories have been proposed for the pathogenesis of these neuropathies. The treatment of most 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 however are controversial. PMID:23642718

  12. Painful diabetic neuropathies, cases report and diagnostic criteria

    Directory of Open Access Journals (Sweden)

    Marco Lacerenza

    2006-12-01

    Full Text Available Painful diabetic neuropathy is a model for the investigation of drug’s efficacy in neuropathic pain. Diabetes, through multiple pathophysiological mechanisms causes several painful neuropathies. In this paper two clinical cases of painful diabetic neuropathic conditions are described and clinical and neurophysiological criteria to make the correct diagnosis are examined. Diabetes causes different painful diabetic neuropathies, at times even in a single patient. Different types of pains may originate from different nerve injuries, and harbour different pathophysiological mechanisms. A comprehensive and accurate evaluation of clinical and neurophysiological abnormalities in painful diabetic neuropathies provides insight on the pathophysiological mechanism and directs the clinician towards rational treatment strategies.

  13. Validity of the neurological examination in diagnosing diabetic peripheral neuropathy.

    Science.gov (United States)

    Höliner, Isabella; Haslinger, Vera; Lütschg, Jürg; Müller, Guido; Barbarini, Daniela Seick; Fussenegger, Jörg; Zanier, Ulrike; Saely, Christoph H; Drexel, Heinz; Simma, Burkhard

    2013-09-01

    The aim of this study was to evaluate the prevalence of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus and examine whether the neurological examination validly diagnoses diabetic peripheral neuropathy as compared with the gold standard of nerve conduction velocity in these patients. Nerve conduction velocity was measured in an unselected consecutive series of patients aged 8-18 years who had been suffering from type 1 diabetes mellitus for at least 1 year. For the neurological examination, neuropathy disability scores and neuropathy sign scores were used. Of the 39 patients, six (15%) had clinically evident diabetic peripheral neuropathy, whereas nerve conduction velocity testing revealed diabetic peripheral neuropathy in 15 (38%) patients. Sensitivity and specificity of the neurological examination for the diagnosis of diabetic peripheral neuropathy were 40% and 100%, respectively. The corresponding positive and negative predictive values were 100% and 72.7%, respectively. This conclusions from this study are that in children and adolescents with type 1 diabetes mellitus, diabetic peripheral neuropathy is highly prevalent, but in the majority of patients it is subclinical. Sensitivity and negative predictive values of the neurological examination are low. Therefore, routine nerve conduction velocity measurement for the assessment of diabetic peripheral neuropathy appears to be warranted in these patients.

  14. Effect of Tinospora cordifolia on experimental diabetic neuropathy

    Directory of Open Access Journals (Sweden)

    Pratibha D Nadig

    2012-01-01

    Conclusions: Tinospora cordifolia prevents the hyperalgesia in experimental diabetic neuropathy. It has an aldose reductase inhibitory activity in-vitro which may contribute to the beneficial effects.

  15. Diabetic neuropathy part 2: proximal and asymmetric phenotypes.

    Science.gov (United States)

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

    2013-05-01

    Diabetic neuropathies consist of a variety of syndromes resulting from different types of damage to peripheral or cranial nerves. Although distal symmetric polyneuropathy is the most common type of diabetic neuropathy, many other subtypes have been defined since the 1800s, including proximal diabetic, truncal, cranial, median, and ulnar neuropathies. Various theories have been proposed for the pathogenesis of these neuropathies. The treatment of most 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 however are controversial.

  16. Focal axonal swellings and associated ultrastructural changes attenuate conduction velocity in central nervous system axons: a computer modeling study.

    Science.gov (United States)

    Kolaric, Katarina V; Thomson, Gemma; Edgar, Julia M; Brown, Angus M

    2013-08-01

    The constancy of action potential conduction in the central nervous system (CNS) relies on uniform axon diameter coupled with fidelity of the overlying myelin providing high-resistance, low capacitance insulation. Whereas the effects of demyelination on conduction have been extensively studied/modeled, equivalent studies on the repercussions for conduction of axon swelling, a common early pathological feature of (potentially reversible) axonal injury, are lacking. The recent description of experimentally acquired morphological and electrical properties of small CNS axons and oligodendrocytes prompted us to incorporate these data into a computer model, with the aim of simulating the effects of focal axon swelling on action potential conduction. A single swelling on an otherwise intact axon, as occurs in optic nerve axons of Cnp1 null mice caused a small decrease in conduction velocity. The presence of single swellings on multiple contiguous internodal regions (INR), as likely occurs in advanced disease, caused qualitatively similar results, except the dimensions of the swellings required to produce equivalent attenuation of conduction were significantly decreased. Our simulations of the consequences of metabolic insult to axons, namely, the appearance of multiple swollen regions, accompanied by perturbation of overlying myelin and increased axolemmal permeability, contained within a single INR, revealed that conduction block occurred when the dimensions of the simulated swellings were within the limits of those measured experimentally, suggesting that multiple swellings on a single axon could contribute to axonal dysfunction, and that increased axolemmal permeability is the decisive factor that promotes conduction block. PMID:24303138

  17. Early ultrastructural defects of axons and axon-glia junctions in mice lacking expression of Cnp1.

    Science.gov (United States)

    Edgar, Julia M; McLaughlin, Mark; Werner, Hauke B; McCulloch, Mailis C; Barrie, Jennifer A; Brown, Angus; Faichney, Andrew Blyth; Snaidero, Nicolas; Nave, Klaus-Armin; Griffiths, Ian R

    2009-12-01

    Most axons in the central nervous system (CNS) are surrounded by a multilayered myelin sheath that promotes fast, saltatory conduction of electrical impulses. By insulating the axon, myelin also shields the axoplasm from the extracellular milieu. In the CNS, oligodendrocytes provide support for the long-term maintenance of myelinated axons, independent of the myelin sheath. Here, we use electron microscopy and morphometric analyses to examine the evolution of axonal and oligodendroglial changes in mice deficient in 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) and in mice deficient in both CNP and proteolipid protein (PLP/DM20). We show that CNP is necessary for the formation of a normal inner tongue process of oligodendrocytes that myelinate small diameter axons. We also show that axonal degeneration in Cnp1 null mice is present very early in postnatal life. Importantly, compact myelin formed by transplanted Cnp1 null oligodendrocytes induces the same degenerative changes in shiverer axons that normally are dysmyelinated but structurally intact. Mice deficient in both CNP and PLP develop a more severe axonal phenotype than either single mutant, indicating that the two oligodendroglial proteins serve distinct functions in supporting the myelinated axon. These observations support a model in which the trophic functions of oligodendrocytes serve to offset the physical shielding of axons by myelin membranes. PMID:19459211

  18. Dynamics of axon fasciculation in the presence of neuronal turnover

    CERN Document Server

    Chaudhuri, Debasish; Mohanty, P K; Zapotocky, Martin

    2008-01-01

    We formulate and characterize a model aiming to describe the formation of fascicles of axons mediated by contact axon-axon interactions. The growing axons are represented as interacting directed random walks in two spatial dimensions. To mimic axonal turnover in the mammalian olfactory system, the random walkers are injected and removed at specified rates. In the dynamical steady state, the position-dependent distribution of fascicle sizes obeys a scaling law. We identify several distinct time scales that emerge from the dynamics, are sensitive functions of the microscopic parameters of the model, and can exceed the average axonal lifetime by orders of magnitude. We discuss our findings in terms of an analytically tractable, effective model of fascicle dynamics.

  19. Action potentials reliably invade axonal arbors of rat neocortical neurons

    OpenAIRE

    Cox, Charles L.; Denk, Winfried; Tank, David W.; Svoboda, Karel

    2000-01-01

    Neocortical pyramidal neurons have extensive axonal arborizations that make thousands of synapses. Action potentials can invade these arbors and cause calcium influx that is required for neurotransmitter release and excitation of postsynaptic targets. Thus, the regulation of action potential invasion in axonal branches might shape the spread of excitation in cortical neural networks. To measure the reliability and extent of action potential invasion into axonal arbors, we have used two-photon...

  20. Myelin sheath survival after guanethidine-induced axonal degeneration

    OpenAIRE

    1992-01-01

    Membrane-membrane interactions between axons and Schwann cells are required for initial myelin formation in the peripheral nervous system. However, recent studies of double myelination in sympathetic nerve have indicated that myelin sheaths continue to exist after complete loss of axonal contact (Kidd, G. J., and J. W. Heath. 1988. J. Neurocytol. 17:245-261). This suggests that myelin maintenance may be regulated either by diffusible axonal factors or by nonaxonal mechanisms. To test these hy...

  1. Axon Regeneration in the Peripheral and Central Nervous Systems

    OpenAIRE

    Huebner, Eric A.; Strittmatter, Stephen M

    2009-01-01

    Axon regeneration in the mature mammalian central nervous system (CNS) is extremely limited after injury. Consequently, functional deficits persist after spinal cord injury (SCI), traumatic brain injury, stroke, and related conditions that involve axonal disconnection. This situation differs from that in the mammalian peripheral nervous system (PNS), where long- distance axon regeneration and substantial functional recovery can occur in the adult. Both extracellular molecules and the intrinsi...

  2. Psychophysical testing in rodent models of glaucomatous optic neuropathy.

    Science.gov (United States)

    Grillo, Stephanie L; Koulen, Peter

    2015-12-01

    Processing of visual information begins in the retina, with photoreceptors converting light stimuli into neural signals. Ultimately, signals are transmitted to the brain through signaling networks formed by interneurons, namely bipolar, horizontal and amacrine cells providing input to retinal ganglion cells (RGCs), which form the optic nerve with their axons. As part of the chronic nature of glaucomatous optic neuropathy, the increasing and irreversible damage and ultimately loss of neurons, RGCs in particular, occurs following progressive damage to the optic nerve head (ONH), eventually resulting in visual impairment and visual field loss. There are two behavioral assays that are typically used to assess visual deficits in glaucoma rodent models, the visual water task and the optokinetic drum. The visual water task can assess an animal's ability to distinguish grating patterns that are associated with an escape from water. The optokinetic drum relies on the optomotor response, a reflex turning of the head and neck in the direction of the visual stimuli, which usually consists of rotating black and white gratings. This reflex is a physiological response critical for keeping the image stable on the retina. Driven initially by the neuronal input from direction-selective RGCs, this reflex is comprised of a number of critical sensory and motor elements. In the presence of repeatable and defined stimuli, this reflex is extremely well suited to analyze subtle changes in the circuitry and performance of retinal neurons. Increasing the cycles of these alternating gratings per degree, or gradually reducing the contrast of the visual stimuli, threshold levels can be determined at which the animal is no longer tracking the stimuli, and thereby visual function of the animal can be determined non-invasively. Integrating these assays into an array of outcome measures that determine multiple aspects of visual function is a central goal in vision research and can be realized, for

  3. Axonal autophagy during regeneration of the rat sciatic nerve

    Institute of Scientific and Technical Information of China (English)

    Kangrong Lu; Zhongxian Piao; Zhenxi Liu; Weiwang Gu; Wanshan Wang; Nngjie Piao

    2008-01-01

    BACKGROUND: The removal of degenerated axonal debris during Wallerian degeneration is very important for nerve regeneration. However, the mechanism by which debris is removed is not been completely understood. Considerable controversy remains as to the clearance pathway and cells that are involved. OBJECTIVE: To investigate axonal autophagy during removal of degenerated axonal debris by transecting the sciatic nerve in a rat Wallerian degeneration model.DESIGN, TIME AND SETTING: Experimental neuropathological analysis. The experiment was conducted at the Laboratory Animal Service Center of the Southern Medical University between January and June 2005. MATERIALS: Fifty-four adult, Wistar rats of either sex, weighing 180-250 g, were obtained from the Laboratory Animal Service Center of the Southern Medical University. Animals were randomly divided into nine groups of six rats. METHODS: Wallerian degeneration was induced by transecting the rat sciatic nerve, and tissue samples from the distal stump were obtained 0.2, 0.4, 1, 2, 3, 4, 7, 10, and 15 days post-transection. Ultrathin sections were prepared for electron microscopy to study ultrastructure and enzyme cytochemistry staining. MAIN OUTCOME MEASURES: Ultrastructure (axon body, autophagic body, and cystoskeleton) of axons and myelin sheaths observed with electron microscopy; acidic phosphatase activity detected by Gomori staining using electron microscopy. RESULTS: The major changes of degenerating axons after transection were axoplasm swelling and separation of axons from their myelin sheath between five hours and two days post-transection. At four days post-transection, the axoplasm condensed and axons were completely separated from the myelin sheath, forming dissociative axon bodies. Vacuoles of different sizes formed in axons during the early phase after lesion. Larger dissociative axon bodies were formed when the axons were completely separated from the myelin sheath during a late phase. The axolemma

  4. Differences in excitability properties of FDI and ADM motor axons.

    Science.gov (United States)

    Bae, Jong Seok; Sawai, Setsu; Misawa, Sonoko; Kanai, Kazuaki; Isose, Sagiri; Kuwabara, Satoshi

    2009-03-01

    The first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles are innervated by the same ulnar nerve, but studies have shown that the former is much more severely affected in amyotrophic lateral sclerosis. In this study, threshold tracking was used to investigate whether membrane properties differ between FDI and ADM motor axons. In 12 normal subjects, compound muscle action potentials were recorded from FDI and ADM after ulnar nerve stimulation at the wrist. The strength-duration time constant was significantly longer in the FDI axons than in the ADM axons, and latent addition studies showed greater threshold changes at the conditioning-test stimulus of 0.2 ms in FDI than in ADM axons. These findings suggest that nodal persistent sodium conductances are more prominent in FDI axons than in ADM axons, and therefore excitability is physiologically higher in FDI axons. Even in the same nerve at the same sites, membrane properties of FDI and ADM motor axons differ significantly, and thus their axonal/neuronal responses to disease may also differ.

  5. Corticostriatal combinatorics: the implications of corticostriatal axonal arborizations.

    Science.gov (United States)

    Zheng, T; Wilson, C J

    2002-02-01

    The complete striatal axonal arborizations of 16 juxtacellularly stained cortical pyramidal cells were analyzed. Corticostriatal neurons were located in the medial agranular or anterior cingulate cortex of rats. All axons were of the extended type and formed synaptic contacts in both the striosomal and matrix compartments as determined by counterstaining for the mu-opiate receptor. Six axonal arborizations were from collaterals of brain stem-projecting cells and the other 10 from bilaterally projecting cells with no brain stem projections. The distribution of synaptic boutons along the axons were convolved with the average dendritic tree volume of spiny projection neurons to obtain an axonal innervation volume and innervation density map for each axon. Innervation volumes varied widely, with single axons occupying between 0.4 and 14.2% of the striatum (average = 4%). The total number of boutons formed by individual axons ranged from 25 to 2,900 (average = 879). Within the innervation volume, the density of innervation was extremely sparse but inhomogeneous. The pattern of innervation resembled matrisomes, as defined by bulk labeling and functional mapping experiments, superimposed on a low background innervation. Using this sample as representative of all corticostriatal axons, the total number of corticostriatal neurons was estimated to be 17 million, about 10 times the number of striatal projection neurons.

  6. Present status of studies on diffuse axonal injury

    Institute of Scientific and Technical Information of China (English)

    Jie Ma; Chonggong Zhang; Yi Li

    2006-01-01

    OBJECTIVE: To explain the present status of study on diffuse axonal injury,investigate its pathogenesis and pathophysiological changes ,and suggest principles for the diagnosis and treatment.DATA SOURCES: Articles about diffuse axonal injury published in English from January 1994 to October 2006 were searched in Pubmed database using the keywords of "diffuse axonal injury,pathogenesis,therapy".STUDY SELECTION: The collected articles were primarily screened to select those associated with diffuse axonal injury,the obviously irrelated articles were excluded,and the rest ones were retrieved manually,and the full-texes were searched.DATA EXTRACTION: Totally 98 articles were collected,41 of them were involved.and the other 57 were excluded.DATA SYNTHESIS: Diffuse axonal injury is mainly caused by acceleratory or deceleratory injury,and its pathophysiological change is a progressive duration,local axonal injury finally develops to axonal breakage,mainly includes inactivation of natrium channel,intracellular Ca2+ overloading,activation of calcium protease,caspase etc.,and mitochondrial injury.At present,there is still lack of effective therapeutic methods for diffuse axonal injury,so we should actively explore more effective methods to relieve the pain of patients and improve their prognosis.CONCLUSION: At present,diffuse axonal injury has not attracted enough attentions in China,the mechanisms for its diagnosis and attack are still unclear,and the treatments are mainly aiming at the symptoms.

  7. Rhesus anti-D immunoglobulin in chronic autoimmune neuropathy

    NARCIS (Netherlands)

    de Jager, AEJ; van der Hoeven, JH

    1998-01-01

    Objective - To investigate the effect of Rhesus anti-D immunoglobulin (anti-D) in patients with an autoimmune demyelinating neuropathy. Material and methods - Three patients with an autoimmune mediated neuropathy received 1000 IU anti-D weekly for 2 months. Results - Two patients worsened gradually

  8. Leber's hereditary optic neuropathy and vitamin B12 deficiency

    NARCIS (Netherlands)

    Pott, Jan Willem R.; Wong, Kwok H.

    2006-01-01

    Background: Leber's hereditary optic neuropathy (LHON) is a maternally inherited optic neuropathy caused by mutations in mitochondrial DNA (mtDNA). It is also believed that several epigenetic factors have an influence on the development of LHON. Methods: A case series was observed. Results: Three pa

  9. An early diagnostic tool for diabetic peripheral neuropathy in rats

    NARCIS (Netherlands)

    Kambiz, S.; Neck, J.W. van; Cosgun, S.G.; Velzen, M.H. van; Janssen, J.A.M.; Avazverdi, N.; Hovius, S.E.; Walbeehm, E.T.

    2015-01-01

    The skin's rewarming rate of diabetic patients is used as a diagnostic tool for early diagnosis of diabetic neuropathy. At present, the relationship between microvascular changes in the skin and diabetic neuropathy is unclear in streptozotocin (STZ) diabetic rats. The aim of this study was to invest

  10. An early diagnostic tool for diabetic peripheral neuropathy in rats

    NARCIS (Netherlands)

    S. Kambiz (Shoista); J.W. van Neck (Han); Cosgun, S.G. (Saniye G.); M.H.N. van Velzen (M. H N); J.A.M.J.L. Janssen (Joseph); Avazverdi, N. (Naim); S.E.R. Hovius (Steven); E.T. Walbeehm (Erik)

    2015-01-01

    textabstractThe skin's rewarming rate of diabetic patients is used as a diagnostic tool for early diagnosis of diabetic neuropathy. At present, the relationship between microvascular changes in the skin and diabetic neuropathy is unclear in streptozotocin (STZ) diabetic rats. The aim of this study w

  11. Lithium-induced motor neuropathy: An unusual presentation

    OpenAIRE

    Satyakam Mohapatra; Manas Ranjan Sahoo; Neelmadhav Rath

    2016-01-01

    Peripheral neuropathy secondary to lithium is under-recognized. Most cases of polyneuropathy were reported with lithium intoxication. However, very few cases were reported without lithium toxicity. We present a case of motor neuropathy due to the use of lithium in a 26-year-old male with a therapeutic lithium level.

  12. Anterior ischemic optic neuropathy in patients undergoing hemodialysis

    NARCIS (Netherlands)

    DoorenbosBot, ACC; Geerlings, W; Houtman, IA

    1996-01-01

    Four patients are discussed who underwent hemodialysis and developed anterior ischemic optic neuropathy (AION). Three patients had been treated by hemodialysis for several years. One patient developed bilateral optic neuropathy after the first hemodialysis session, So far, only four hemodialysis pat

  13. Dopaminergic axon guidance: which makes what?

    Directory of Open Access Journals (Sweden)

    Laetitia ePrestoz

    2012-07-01

    Full Text Available Mesotelencephalic pathways in the adult central nervous system have been studied in great detail because of their implication in major physiological functions as well as in psychiatric, neurological and neurodegenerative diseases. However, the ontogeny of these pathways and the molecular mechanisms that guide dopaminergic axons during embryogenesis have been only recently studied. This line of research is of crucial interest for the repair of lesioned circuits in adulthood following neurodegenerative diseases or common traumatic injuries. For instance, in the adult, the anatomic and functional repair of the nigrostriatal pathway following dopaminergic embryonic neuron transplantation suggests that specific guidance cues exist which govern embryonic fibers outgrowth, and suggests that axons from transplanted embryonic cells are able to respond to theses cues, which then guide them to their final targets. In this review, we first synthesize the work that has been performed in the last few years on developing mesotelencephalic pathways, and summarize the current knowledge on the identity of cellular and molecular signals thought to be involved in establishing mesotelencephalic dopaminergic neuronal connectivity during embryogenesis in the central nervous system of rodents. Then, we review the modulation of expression of these molecular signals in the lesioned adult brain and discuss their potential role in remodeling the mesotelencephalic dopaminergic circuitry, with a particular focus on Parkinson’s disease. Identifying guidance molecules involved in the connection of grafted cells may be useful for cellular therapy in Parkinsonian patients, as these molecules may help direct axons from grafted cells along the long distance they have to travel from the substantia nigra to the striatum.

  14. Patterns of growth, axonal extension and axonal arborization of neuronal lineages in the developing Drosophila brain.

    Science.gov (United States)

    Larsen, Camilla; Shy, Diana; Spindler, Shana R; Fung, Siaumin; Pereanu, Wayne; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2009-11-15

    The Drosophila central brain is composed of approximately 100 paired lineages, with most lineages comprising 100-150 neurons. Most lineages have a number of important characteristics in common. Typically, neurons of a lineage stay together as a coherent cluster and project their axons into a coherent bundle visible from late embryo to adult. Neurons born during the embryonic period form the primary axon tracts (PATs) that follow stereotyped pathways in the neuropile. Apoptotic cell death removes an average of 30-40% of primary neurons around the time of hatching. Secondary neurons generated during the larval period form secondary axon tracts (SATs) that typically fasciculate with their corresponding primary axon tract. SATs develop into the long fascicles that interconnect the different compartments of the adult brain. Structurally, we distinguish between three types of lineages: PD lineages, characterized by distinct, spatially separate proximal and distal arborizations; C lineages with arborizations distributed continuously along the entire length of their tract; D lineages that lack proximal arborizations. Arborizations of many lineages, in particular those of the PD type, are restricted to distinct neuropile compartments. We propose that compartments are "scaffolded" by individual lineages, or small groups thereof. Thereby, the relatively small number of primary neurons of each primary lineage set up the compartment map in the late embryo. Compartments grow during the larval period simply by an increase in arbor volume of primary neurons. Arbors of secondary neurons form within or adjacent to the larval compartments, resulting in smaller compartment subdivisions and additional, adult specific compartments. PMID:19538956

  15. Decreased myocardial perfusion reserve in diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Taskiran, Mustafa; Fritz-Hansen, Thomas; Rasmussen, Verner;

    2002-01-01

    The pathophysiological mechanisms responsible for increased cardiovascular mortality in diabetic autonomic neuropathy are unknown. To investigate the effect of autonomic neuropathy on myocardial function, we performed dynamic contrast-enhanced magnetic resonance perfusion imaging during baseline...... conditions and after Dipyridamole-induced vasodilatation in nine type 1 diabetic patients with autonomic neuropathy (AN+), defined by cardiovascular tests, as well as in 10 type 1 diabetic patients without autonomic neuropathy (AN-) and 10 healthy control subjects. Baseline myocardial perfusion index (K...... blood pressure response to Dipyridamole and myocardial perfusion reserve index. We conclude that type 1 diabetic patients with autonomic neuropathy have a decreased myocardial perfusion reserve capacity when challenged with a vasodilatator, a finding that may in part be the pathophysiological substrate...

  16. Focal axonal swellings and associated ultrastructural changes attenuate conduction velocity in central nervous system axons: a computer modeling study

    OpenAIRE

    Kolaric, Katarina V; Thomson, Gemma; Edgar, Julia M; Brown, Angus M.

    2013-01-01

    The constancy of action potential conduction in the central nervous system (CNS) relies on uniform axon diameter coupled with fidelity of the overlying myelin providing high-resistance, low capacitance insulation. Whereas the effects of demyelination on conduction have been extensively studied/modeled, equivalent studies on the repercussions for conduction of axon swelling, a common early pathological feature of (potentially reversible) axonal injury, are lacking. The recent description of ex...

  17. Progression of motor axon dysfunction and ectopic Nav1.8 expression in a mouse model of Charcot-Marie-Tooth disease 1B.

    Science.gov (United States)

    Rosberg, Mette R; Alvarez, Susana; Klein, Dennis; Nielsen, Finn Cilius; Martini, Rudolf; Levinson, S Rock; Krarup, Christian; Moldovan, Mihai

    2016-09-01

    Mice heterozygously deficient for the myelin protein P0 gene (P0+/-) develop a slowly progressing neuropathy modeling demyelinating Charcot-Marie-Tooth disease (CMT1B). The aim of the study was to investigate the long-term progression of motor dysfunction in P0+/- mice at 3, 7, 12 and 20months. By comparison with WT littermates, P0+/- showed a decreasing motor performance with age. This was associated with a progressive reduction in amplitude and increase in latency of the plantar compound muscle action potential (CMAP) evoked by stimulation of the tibial nerve at ankle. This progressive functional impairment was in contrast to the mild demyelinating neuropathy of the tibial nerve revealed by histology. "Threshold-tracking" studies showed impaired motor axon excitability in P0+/- from 3months. With time, there was a progressive reduction in threshold deviations during both depolarizing and hyperpolarizing threshold electrotonus associated with increasing resting I/V slope and increasing strength-duration time constant. These depolarizing features in excitability in P0+/- as well as the reduced CMAP amplitude were absent in P0+/- NaV1.8 knockouts, and could be acutely reversed by selective pharmacologic block of NaV1.8 in P0+/-. Mathematical modeling indicated an association of altered passive cable properties with a depolarizing shift in resting membrane potential and increase in the persistent Na(+) current in P0+/-. Our data suggest that ectopic NaV1.8 expression precipitates depolarizing conduction failure in CMT1B, and that motor axon dysfunction in demyelinating neuropathy is pharmacologically reversible. PMID:27215377

  18. Sciatic neuropathy developed after injection during curettage.

    Science.gov (United States)

    Altıntaş, Ayşe; Gündüz, Ayşegül; Kantarcı, Fatih; Gözübatık Çelik, Gökçen; Koçer, Naci; Kızıltan, Meral E

    2016-01-01

    Intramuscular injections are likely the most common cause of sciatic nerve injury in developing countries. Less common causes include piriformis syndrome, primary tumors of the sciatic nerve, metastatic tumors invading or compressing the nerve, endometriosis, vascular malformations, and prolonged immobilization or positioning. While the most reliable diagnostic and prognostic methods include nerve conduction studies and electromyography, magnetic resonance imaging has been suggested as an alternative method of determining type of lesion, establishing location, and investigating level of nerve involvement. A case of sciatic neuropathy that developed after intramuscular injection, with patient in prolonged lithotomy position and under sedation, is described. PMID:27225613

  19. Auditory Neuropathy/Dyssynchrony in Biotinidase Deficiency

    Science.gov (United States)

    Yaghini, Omid

    2016-01-01

    Biotinidase deficiency is a disorder inherited autosomal recessively showing evidence of hearing loss and optic atrophy in addition to seizures, hypotonia, and ataxia. In the present study, a 2-year-old boy with Biotinidase deficiency is presented in which clinical symptoms have been reported with auditory neuropathy/auditory dyssynchrony (AN/AD). In this case, transient-evoked otoacoustic emissions showed bilaterally normal responses representing normal function of outer hair cells. In contrast, acoustic reflex test showed absent reflexes bilaterally, and visual reinforcement audiometry and auditory brainstem responses indicated severe to profound hearing loss in both ears. These results suggest AN/AD in patients with Biotinidase deficiency. PMID:27144235

  20. INFLUENCE ON VESTIBULAR FUNCTION BY AUDITORY NEUROPATHY

    Institute of Scientific and Technical Information of China (English)

    WANG Jingmiao; JIANG Xinxia; SHAN Chunguang

    2013-01-01

    Objective The main purpose of the present study was to describe the vestibular function in patients with auditory neuropathy (AN), and to assess their ability to maintain balance. Methods Vestibular function tests were performed on 32 patients with AN and 36 normal subjects including electronystagmopraphy(ENG) and static postrography(SPG). The results from the two groups were compared. Results Equilibrium function in patients with AN, was abnormal, compared to normal subjects. Conclusion Vestibular function tests, espe-cially static postrography, should be performed on patients with AN.

  1. Clinical features and electrodiagnosis of ulnar neuropathies.

    Science.gov (United States)

    Landau, Mark E; Campbell, William W

    2013-02-01

    In this review, we delineate clinical, electrodiagnostic, and radiographic features of ulnar mononeuropathies. Ulnar neuropathy at the elbow (UNE) is most commonly due to lesions at the level of the retroepicondylar groove (RTC), with approximately 25% at the humeroulnar arcade (HUA). The term 'cubital tunnel syndrome' should be reserved for the latter. The diagnostic accuracy of nerve conduction studies is limited by biological (e.g. low elbow temperature) and technical factors. Across-elbow distance measurements greater than 10 cm improve diagnostic specificity at the expense of decreased sensitivity. Short-segment incremental studies can differentiate lesions at the HUA from those at the RTC.

  2. Neuro-vascular-desmal relationship disturbances in peripheral nerves, dorsal root ganglions and motor segmental centers in the etoposide-induced neuropathy.

    Directory of Open Access Journals (Sweden)

    Gerashchenko S.B.

    2007-01-01

    Full Text Available The purpose of work was to determine the mechanisms of pathologic morphogenesis of the toxic neuropathy caused by etoposide taking into consideration all complex the neuro-vascular-desmal relationship disturbances in peripheral nerves, their motor and sensor segmental centers. It has been shown in the experiments on 86 white rats that single intravenous injection of etoposide at dose of 22 mg/kg body weight induse peripheral neuropathy. The complex of morphologic methods included the neurohistological and electronic microscopic methods of the research, the histochemical markers for study transmissivity of the vessels of the circulatory bed on the light microscopic and ultrastructural levels was used. The recommendations of the Interagency Committee of Neurotoxicology were considered to choose the methods of the research. The presence of 3 stages of morphogenesis has been established - phase of primary axonal reaction (3d day of experiment, phase of disturbance of the microcirculation of peripheral nerves and their segmental centers (7th day of experiment, phase of degenerative changes (15th day. Etoposide-indused neuropathy features are determined by a singularity of interdependent reactive changes, alteration and compensation processes in sensory and motor neurons, glial cells, microcirculatory bed and connective tissue.

  3. Diagnosis and classification of autoimmune optic neuropathy.

    Science.gov (United States)

    Petzold, Axel; Plant, Gordon T

    2014-01-01

    The spectrum of autoimmune optic neuropathies (ON) is extending. The phenotypic spectrum includes single isolated optic neuritis (SION), relapsing isolated optic neuritis (RION), chronic relapsing inflammatory optic neuropathy (CRION), the neuromyelitis optica (NMO) spectrum disorder, multiple sclerosis associated optic neuritis (MSON) and unclassified optic neuritis (UCON) forms. Epidemiological data suggests a slight female predominance. The ethnic heritage is relevant as Caucasian patients are more likely to suffer from MSON, whilst SION, RION, CRION and NMO are more frequent in non-Caucasian patients. Importantly, prognosis for recovery of visual function is good in MSON, but poorer in NMO and CRION which also have a high chance for recurrent episodes. Testing for serum anti-AQP4 autoantibodies is advised in all patients with severe, atypical or recurrent ON because of the high diagnostic specificity. The diagnostic specificity may be aided by testing for glial biomarkers in the CSF and prognostic accuracy by testing for biomarkers for neuroaxonal degeneration. Optical coherence tomography is a highly accurate tool to document the final outcome. The current clinical classification criteria rely on the phenotype, response to treatment and presence of anti-AQP4 autoantibodies.

  4. Early diabetic neuropathy: Triggers and mechanisms

    Institute of Scientific and Technical Information of China (English)

    Maxim Dobretsov; Dmitry Romanovsky; Joseph R Stimers

    2007-01-01

    Peripheral neuropathy, and specifically distal peripheral neuropathy (DPN), is one of the most frequent and troublesome complications of diabetes mellitus. It is the major reason for morbidity and mortality among diabetic patients, It is also frequently associated with debilitating pain. Unfortunately, our knowledge of the natural history and pathogenesis of this disease remains limited. For a long time hyperglycemia was viewed as a major, if not the sole factor, responsible for all symptomatic presentations of DPN. Multiple clinical observations and animal studies supported this view. The control of blood glucose as an obligatory step of therapy to delay or reverse DPN is no longer an arguable issue. However, while supporting evidence for the glycemic hypothesis has accumulated, multiple controversies accumulated as well.It is obvious now that DPN cannot be fully understood without considering factors besides hyperglycemia. Some symptoms of DPN may develop with little, if any, correlation with the glycemic status of a patient. It is also clear that identification of these putative non-glycemic mechanisms of DPN is of utmost importance for our understanding of failures with existing treatments and for the development of new approaches for diagnosis and therapy of DPN. In this work we will review the strengths and weaknesses of the glycemic hypothesis, focusing on clinical and animal data and on the pathogenesis of early stages and triggers of DPN other than hyperglycemia.

  5. Treating Painful Diabetic Peripheral Neuropathy: An Update.

    Science.gov (United States)

    Snyder, Matthew J; Gibbs, Lawrence M; Lindsay, Tammy J

    2016-08-01

    Painful diabetic peripheral neuropathy occurs in approximately 25% of patients with diabetes mellitus who are treated in the office setting and significantly affects quality of life. It typically causes burning pain, paresthesias, and numbness in a stocking-glove pattern that progresses proximally from the feet and hands. Clinicians should carefully consider the patient's goals and functional status and potential adverse effects of medication when choosing a treatment for painful diabetic peripheral neuropathy. Pregabalin and duloxetine are the only medications approved by the U.S. Food and Drug Administration for treating this disorder. Based on current practice guidelines, these medications, with gabapentin and amitriptyline, should be considered for the initial treatment. Second-line therapy includes opioid-like medications (tramadol and tapentadol), venlafaxine, desvenlafaxine, and topical agents (lidocaine patches and capsaicin cream). Isosorbide dinitrate spray and transcutaneous electrical nerve stimulation may provide relief in some patients and can be considered at any point during therapy. Opioids and selective serotonin reuptake inhibitors are optional third-line medications. Acupuncture, traditional Chinese medicine, alpha lipoic acid, acetyl-l-carnitine, primrose oil, and electromagnetic field application lack high-quality evidence to support their use. PMID:27479625

  6. Leber hereditary optic neuropathy: current perspectives

    Science.gov (United States)

    Meyerson, Cherise; Van Stavern, Greg; McClelland, Collin

    2015-01-01

    Leber hereditary optic neuropathy (LHON) is one of the most common inherited optic neuropathies causing bilateral central vision loss. The disorder results from point mutations in mitochondrial DNA and subsequent mitochondrial dysfunction. The primary cell type that is lost in LHON is the retinal ganglion cell, which is highly susceptible to disrupted ATP production and oxidative stress. Inheritance of LHON follows that of mitochondrial genetics, and it has a highly variable clinical phenotype, as other genetic and environmental factors also play a role. Although LHON usually presents with isolated vision loss, some patients suffer other neurological sequelae. For ill-defined reasons, male LHON mutation carriers are more affected than females. Most LHON patients remain legally blind, but a small proportion can experience spontaneous partial recovery, often within the first year of symptom onset. Unfortunately, at this time there are no established curative interventions and treatment is largely supportive. Patients should be offered low vision services and counseled on mitigating risk factors for additional vision loss, such as smoking and consuming alcohol. Encouraging treatments currently undergoing investigation includes ubiquinone analogs, such as idebenone, as well as gene therapy and stem cells to restore ATP synthesis and provide neuroprotection to surviving retinal ganglion cells. PMID:26170609

  7. Molecular genetics of hereditary sensory neuropathies.

    Science.gov (United States)

    Auer-Grumbach, Michaela; Mauko, Barbara; Auer-Grumbach, Piet; Pieber, Thomas R

    2006-01-01

    Hereditary sensory neuropathies (HSN), also known as hereditary sensory and autonomic neuropathies (HSAN), are a clinically and genetically heterogeneous group of disorders. They are caused by neuronal atrophy and degeneration, predominantly affecting peripheral sensory and autonomic neurons. Both congenital and juvenile to adulthood onset is possible. Currently, the classification of the HSN depends on the mode of inheritance, age at onset, and clinical presentation. Hallmark features are progressive sensory loss, chronic skin ulcers, and other skin abnormalities. Spontaneous fractures and neuropathic arthropathy are frequent complications and often necessitate amputations. Autonomic features vary between different subgroups. Distal muscle weakness and wasting may be present and is sometimes so prominent that it becomes difficult to distinguish HSN from Charcot-Marie-Tooth syndrome. Recent major advances in molecular genetics have led to the identification of seven gene loci and six-disease causing genes for autosomal-dominant and autosomal-recessive HSN. These genes have been shown to play roles in lipid metabolism and the regulation of intracellular vesicular transport, but also a presumptive transcriptional regulator, a nerve growth factor receptor, and a nerve growth factor have been described among the causative genes in HSN. Nevertheless, it remains unclear how mutations in the known genes lead to the phenotype of HSN. In this review, we summarize the recent progress of the molecular genetics of the HSN and the implicated genes.

  8. Immediate and delayed cochlear neuropathy after noise exposure in pubescent mice.

    Directory of Open Access Journals (Sweden)

    Jane Bjerg Jensen

    Full Text Available Moderate acoustic overexposure in adult rodents is known to cause acute loss of synapses on sensory inner hair cells (IHCs and delayed degeneration of the auditory nerve, despite the completely reversible temporary threshold shift (TTS and morphologically intact hair cells. Our objective was to determine whether a cochlear synaptopathy followed by neuropathy occurs after noise exposure in pubescence, and to define neuropathic versus non-neuropathic noise levels for pubescent mice. While exposing 6 week old CBA/CaJ mice to 8-16 kHz bandpass noise for 2 hrs, we defined 97 dB sound pressure level (SPL as the threshold for this particular type of neuropathic exposure associated with TTS, and 94 dB SPL as the highest non-neuropathic noise level associated with TTS. Exposure to 100 dB SPL caused permanent threshold shift although exposure of 16 week old mice to the same noise is reported to cause only TTS. Amplitude of wave I of the auditory brainstem response, which reflects the summed activity of the cochlear nerve, was complemented by synaptic ribbon counts in IHCs using confocal microscopy, and by stereological counts of peripheral axons and cell bodies of the cochlear nerve from 24 hours to 16 months post exposure. Mice exposed to neuropathic noise demonstrated immediate cochlear synaptopathy by 24 hours post exposure, and delayed neurodegeneration characterized by axonal retraction at 8 months, and spiral ganglion cell loss at 8-16 months post exposure. Although the damage was initially limited to the cochlear base, it progressed to also involve the cochlear apex by 8 months post exposure. Our data demonstrate a fine line between neuropathic and non-neuropathic noise levels associated with TTS in the pubescent cochlea.

  9. Inhibiting poly(ADP-ribosylation) improves axon regeneration

    Science.gov (United States)

    Byrne, Alexandra B; McWhirter, Rebecca D; Sekine, Yuichi; Strittmatter, Stephen M; Miller, David M; Hammarlund, Marc

    2016-01-01

    The ability of a neuron to regenerate its axon after injury depends in part on its intrinsic regenerative potential. Here, we identify novel intrinsic regulators of axon regeneration: poly(ADP-ribose) glycohodrolases (PARGs) and poly(ADP-ribose) polymerases (PARPs). PARGs, which remove poly(ADP-ribose) from proteins, act in injured C. elegans GABA motor neurons to enhance axon regeneration. PARG expression is regulated by DLK signaling, and PARGs mediate DLK function in enhancing axon regeneration. Conversely, PARPs, which add poly(ADP-ribose) to proteins, inhibit axon regeneration of both C. elegans GABA neurons and mammalian cortical neurons. Furthermore, chemical PARP inhibitors improve axon regeneration when administered after injury. Our results indicate that regulation of poly(ADP-ribose) levels is a critical function of the DLK regeneration pathway, that poly-(ADP ribosylation) inhibits axon regeneration across species, and that chemical inhibition of PARPs can elicit axon regeneration. DOI: http://dx.doi.org/10.7554/eLife.12734.001

  10. New insights into mRNA trafficking in axons

    NARCIS (Netherlands)

    Gumy, Laura; Katrukha, Eugene; Kapitein, Lukas; Hoogenraad, Casper

    2014-01-01

    In recent years, it has been demonstrated that mRNAs localize to axons of young and mature central and peripheral nervous system neurons in culture and in vivo. Increasing evidence is supporting a fundamental role for the local translation of these mRNAs in neuronal function by regulating axon growt

  11. Spontaneous axonal regeneration in rodent spinal cord after ischemic injury

    DEFF Research Database (Denmark)

    von Euler, Mia; Janson, A M; Larsen, Jytte Overgaard;

    2002-01-01

    Here we present evidence for spontaneous and long-lasting regeneration of CNS axons after spinal cord lesions in adult rats. The length of 200 kD neurofilament (NF)-immunolabeled axons was estimated after photochemically induced ischemic spinal cord lesions using a stereological tool. The total l...

  12. The frequency of peripheral neuropathy in a group of HIV positive patients in Brazil Freqüência da neuropatia periférica no Brasil em um grupo de pacientes HIV positivo

    Directory of Open Access Journals (Sweden)

    Claudia Zanetti

    2004-06-01

    Full Text Available Peripheral neuropathy is a common neurological complication occurring in asymptomatic and symptomatic stages of HIV infection. The most common syndromes are distal symmetric polyneuropathy, inflammatory demielinating polyneuropathy, poliradiculopathy, mononeuropathy, mononeuropathy multiplex and autonomic neuropathy. PURPOSE: To evaluate the frequency of peripheral neuropathy in a group of HIV seropositive outpatients in São Paulo, Brazil. METHOD: Over a period of 17 months, 49 HIV+ patients where evaluated clinically. Laboratory analysis and electroneuromyography were requested to all patients. RESULTS: >Thirty four (69.4% of the 49 patients had the diagnosis of peripheral neuropathy established on clinical grounds. The most common sign was impairment (97.1% of sensibility. Thirteen (33.3% of the 39 that were subjected to electroneuromyography had features of peripheral neuropathy, being a sensitive-motor axonal neuropathy the most common. No abnormalities were found in the laboratory analysis performed in 42 patients, except in four who had VDRL positive. CONCLUSION: A peripheral neuropathy was frequently found upon clinical examination in our group of HIV positive individuals.A neuropatia periférica é complicação neurológica comum, podendo ocorrer nas fases assintomáticas e sintomáticas da infecção pelo vírus da imunodeficiência humana (HIV. As síndromes mais comuns são a polineuropatia distal simétrica, polineuropatia desmielinizante inflamatória, polirradiculopatia, mononeuropatia, mononeuropatia múltipla e neuropatia autonômica. OBJETIVO: Avaliar a freqüência da neuropatia periférica em um grupo de pacientes HIV positivo em São Paulo, Brasil. MÉTODO: Em um período de 17 meses, foram avaliados clinicamente 49 pacientes HIV positivos. Foram solicitados exames laboratoriais e eletroneuromiografia (ENMG para todos os pacientes. RESULTADOS: Foi estabelecido o diagnóstico clínico de neuropatia periférica em 34 (69

  13. SnoN facilitates axonal regeneration after spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Jiun L Do

    Full Text Available Adult CNS neurons exhibit a reduced capacity for growth compared to developing neurons, due in part to downregulation of growth-associated genes as development is completed. We tested the hypothesis that SnoN, an embryonically regulated transcription factor that specifies growth of the axonal compartment, can enhance growth in injured adult neurons. In vitro, SnoN overexpression in dissociated adult DRG neuronal cultures significantly enhanced neurite outgrowth. Moreover, TGF-β1, a negative regulator of SnoN, inhibited neurite outgrowth, and SnoN over-expression overcame this inhibition. We then examined whether SnoN influenced axonal regeneration in vivo: indeed, expression of a mutant form of SnoN resistant to degradation significantly enhanced axonal regeneration following cervical spinal cord injury, despite peri-lesional upregulation of TGF-β1. Thus, a developmental mechanism that specifies extension of the axonal compartment also promotes axonal regeneration after adult CNS injury.

  14. Receptor Tyrosine Kinases: Molecular Switches Regulating CNS Axon Regeneration

    Directory of Open Access Journals (Sweden)

    Vasanthy Vigneswara

    2012-01-01

    Full Text Available The poor or lack of injured adult central nervous system (CNS axon regeneration results in devastating consequences and poor functional recovery. The interplay between the intrinsic and extrinsic factors contributes to robust inhibition of axon regeneration of injured CNS neurons. The insufficient or lack of trophic support for injured neurons is considered as one of the major obstacles contributing to their failure to survive and regrow their axons after injury. In the CNS, many of the signalling pathways associated with neuronal survival and axon regeneration are regulated by several classes of receptor tyrosine kinases (RTK that respond to a variety of ligands. This paper highlights and summarises the most relevant recent findings pertinent to different classes of the RTK family of molecules, with a particular focus on elucidating their role in CNS axon regeneration.

  15. Rare Variants in MME, Encoding Metalloprotease Neprilysin, Are Linked to Late-Onset Autosomal-Dominant Axonal Polyneuropathies.

    Science.gov (United States)

    Auer-Grumbach, Michaela; Toegel, Stefan; Schabhüttl, Maria; Weinmann, Daniela; Chiari, Catharina; Bennett, David L H; Beetz, Christian; Klein, Dennis; Andersen, Peter M; Böhme, Ilka; Fink-Puches, Regina; Gonzalez, Michael; Harms, Matthew B; Motley, William; Reilly, Mary M; Renner, Wilfried; Rudnik-Schöneborn, Sabine; Schlotter-Weigel, Beate; Themistocleous, Andreas C; Weishaupt, Jochen H; Ludolph, Albert C; Wieland, Thomas; Tao, Feifei; Abreu, Lisa; Windhager, Reinhard; Zitzelsberger, Manuela; Strom, Tim M; Walther, Thomas; Scherer, Steven S; Züchner, Stephan; Martini, Rudolf; Senderek, Jan

    2016-09-01

    Axonal polyneuropathies are a frequent cause of progressive disability in the elderly. Common etiologies comprise diabetes mellitus, paraproteinaemia, and inflammatory disorders, but often the underlying causes remain elusive. Late-onset axonal Charcot-Marie-Tooth neuropathy (CMT2) is an autosomal-dominantly inherited condition that manifests in the second half of life and is genetically largely unexplained. We assumed age-dependent penetrance of mutations in a so far unknown gene causing late-onset CMT2. We screened 51 index case subjects with late-onset CMT2 for mutations by whole-exome (WES) and Sanger sequencing and subsequently queried WES repositories for further case subjects carrying mutations in the identified candidate gene. We studied nerve pathology and tissue levels and function of the abnormal protein in order to explore consequences of the mutations. Altogether, we observed heterozygous rare loss-of-function and missense mutations in MME encoding the metalloprotease neprilysin in 19 index case subjects diagnosed with axonal polyneuropathies or neurodegenerative conditions involving the peripheral nervous system. MME mutations segregated in an autosomal-dominant fashion with age-related incomplete penetrance and some affected individuals were isolated case subjects. We also found that MME mutations resulted in strongly decreased tissue availability of neprilysin and impaired enzymatic activity. Although neprilysin is known to degrade β-amyloid, we observed no increased amyloid deposition or increased incidence of dementia in individuals with MME mutations. Detection of MME mutations is expected to increase the diagnostic yield in late-onset polyneuropathies, and it will be tempting to explore whether substances that can elevate neprilysin activity could be a rational option for treatment. PMID:27588448

  16. Diabetic peripheral neuropathy: current perspective and future directions.

    Science.gov (United States)

    Singh, Randhir; Kishore, Lalit; Kaur, Navpreet

    2014-02-01

    Diabetic neuropathy is a heterogeneous group of disorders with extremely complex pathophysiology and affects both somatic and autonomic components of the nervous system. Neuropathy is the most common chronic complication of diabetes mellitus. Metabolic disruptions in the peripheral nervous system, including altered protein kinase C activity, and increased polyol pathway activity in neurons and Schwann cells resulting from hyperglycemia plays a key role in the development of diabetic neuropathy. These pathways are related to the metabolic and/or redox state of the cell and are the major source of damage. Activation of these metabolic pathways leads to oxidative stress, which is a mediator of hyperglycemia induced cell injury and a unifying theme for all mechanisms of diabetic neuropathy. The therapeutic intervention of these metabolic pathways is capable of ameliorating diabetic neuropathy but therapeutics which target one particular mechanism may have a limited success. Available therapeutic approaches are based upon the agents that modulate pathogenetic mechanisms (glycemic control) and relieve the symptoms of diabetic neuropathy. This review emphasizes the pathogenesis, presently available therapeutic approaches and future directions for the management of diabetic neuropathy.

  17. Wherefore Art Thou, O Treatment for Diabetic Neuropathy?

    Science.gov (United States)

    Malik, R A

    2016-01-01

    As of March 2016, we continue to advocate the diagnosis of diabetic neuropathy using a simple foot examination or monofilament, which identifies only those with severe neuropathy and hence risk of foot ulceration. Given the fact that the 5-year mortality rate of diabetic patients with foot ulceration is worse than that of most common cancers, surely we should be identifying patients at an earlier stage of neuropathy to prevent its progression to a stage with such a high mortality? Of course, we lament that there is no licensed treatment for diabetic neuropathy. Who is to blame? As researchers and carers, we have a duty of care to our patients with diabetic neuropathy. So, we have to look forward not backwards, and move away from our firmly entrenched views on the design and conduct of clinical trials for diabetic neuropathy. Relevant organizations such as Neurodiab, the American Diabetes Association and the Peripheral Nerve Society have to acknowledge that they cannot continue to endorse a bankrupt strategy. The FDA needs an open and self-critical dialogue with these organizations, to give pharmaceutical companies at least a fighting chance to deliver effective new therapies for diabetic neuropathy.

  18. Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease

    Directory of Open Access Journals (Sweden)

    Laurent P. Bogdanik

    2013-05-01

    Charcot-Marie-Tooth disease (CMT is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P. Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.

  19. Tolerability and efficacy study of P2X7 inhibition in experimental Charcot-Marie-Tooth type 1A (CMT1A) neuropathy.

    Science.gov (United States)

    Sociali, Giovanna; Visigalli, Davide; Prukop, Thomas; Cervellini, Ilaria; Mannino, Elena; Venturi, Consuelo; Bruzzone, Santina; Sereda, Michael W; Schenone, Angelo

    2016-11-01

    Charcot-Marie-Tooth 1A (CMT1A) is a demyelinating hereditary neuropathy for which pharmacological treatments are not yet available. An abnormally high intracellular Ca(2+) concentration was observed in Schwann cells (SC) from CMT1A rats, caused by the PMP22-mediated overexpression of the P2X7 purinoceptor. The purpose of this study was to investigate the tolerability and therapeutic potential of a pharmacological antagonist of the P2X7 receptor (A438079) in CMT1A. A438079 ameliorated in vitro myelination of organotypic DRG cultures from CMT1A rats. Furthermore, we performed an experimental therapeutic trial in PMP22 transgenic and in wild-type rats. A preliminary dose-escalation trial showed that 3mg/kg A438079 administered via intraperitoneal injection every 24h for four weeks was well tolerated by wild type and CMT1A rats. Affected rats treated with 3mg/kg A438079 revealed a significant improvement of the muscle strength, when compared to placebo controls. Importantly, histologic analysis revealed a significant increase of the total number of myelinated axons in tibial nerves. Moreover, a significant decrease of the hypermyelination of small caliber axons and a significant increase of the frequency and diameter of large caliber myelinated axons was highlighted. An improved distal motor latencies was recorded, whereas compound muscle action potentials (CMAP) remained unaltered. A438079 reduced the SC differentiation defect in CMT1A rats. These results show that pharmacological inhibition of the P2X7 receptor is well tolerated in CMT1A rats and represents a proof-of-principle that antagonizing this pathway may correct the molecular derangements and improve the clinical phenotype in the CMT1A neuropathy. PMID:27431093

  20. Signaling mechanisms in cortical axon growth, guidance and branching

    Directory of Open Access Journals (Sweden)

    Katherine eKalil

    2011-09-01

    Full Text Available Precise wiring of cortical circuits during development depends upon axon extension, guidance and branching to appropriate targets. Motile growth cones at axon tips navigate through the nervous system by responding to molecular cues, which modulate signaling pathways within axonal growth cones. Intracellular calcium signaling has emerged as a major transducer of guidance cues but exactly how calcium signaling pathways modify the actin and microtubule cytoskeleton to evoke growth cone behaviors and axon branching is still mysterious. Axons must often pause in their outgrowth while their branches extend into targets. Some evidence suggests a competition between growth of axons and branches but the mechanisms are poorly understood. Since it is difficult to study growing axons deep within the mammalian brain, much of what we know about signaling pathways and cytoskeletal dynamics has come from studies of axonal growth cones, in many cases from non-mammalian species, growing in tissue culture. Consequently it is not well understood how guidance cues relevant to mammalian neural development in vivo signal to the growth cone cytoskeleton during axon outgrowth and guidance. In this review we describe our recent work in dissociated cultures of developing rodent sensorimotor cortex in the context of the current literature on molecular guidance cues, calcium signaling pathways and cytoskeletal dynamics that regulate growth cone behaviors. A major challenge is to relate findings in tissue culture to mechanisms of cortical development in vivo. Toward this goal, we describe our recent work in cortical slices, which preserve the complex cellular and molecular environment of the mammalian brain but allow direct visualization of growth cone behaviors and calcium signaling. Findings from this work suggest that mechanisms regulating axon growth and guidance in dissociated culture neurons also underlie development of cortical connectivity in vivo.

  1. Brain injury tolerance limit based on computation of axonal strain.

    Science.gov (United States)

    Sahoo, Debasis; Deck, Caroline; Willinger, Rémy

    2016-07-01

    Traumatic brain injury (TBI) is the leading cause of death and permanent impairment over the last decades. In both the severe and mild TBIs, diffuse axonal injury (DAI) is the most common pathology and leads to axonal degeneration. Computation of axonal strain by using finite element head model in numerical simulation can enlighten the DAI mechanism and help to establish advanced head injury criteria. The main objective of this study is to develop a brain injury criterion based on computation of axonal strain. To achieve the objective a state-of-the-art finite element head model with enhanced brain and skull material laws, was used for numerical computation of real world head trauma. The implementation of new medical imaging data such as, fractional anisotropy and axonal fiber orientation from Diffusion Tensor Imaging (DTI) of 12 healthy patients into the finite element brain model was performed to improve the brain constitutive material law with more efficient heterogeneous anisotropic visco hyper-elastic material law. The brain behavior has been validated in terms of brain deformation against Hardy et al. (2001), Hardy et al. (2007), and in terms of brain pressure against Nahum et al. (1977) and Trosseille et al. (1992) experiments. Verification of model stability has been conducted as well. Further, 109 well-documented TBI cases were simulated and axonal strain computed to derive brain injury tolerance curve. Based on an in-depth statistical analysis of different intra-cerebral parameters (brain axonal strain rate, axonal strain, first principal strain, Von Mises strain, first principal stress, Von Mises stress, CSDM (0.10), CSDM (0.15) and CSDM (0.25)), it was shown that axonal strain was the most appropriate candidate parameter to predict DAI. The proposed brain injury tolerance limit for a 50% risk of DAI has been established at 14.65% of axonal strain. This study provides a key step for a realistic novel injury metric for DAI. PMID:27038501

  2. Peripheral Nerve Ultrasonography in Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Multifocal Motor Neuropathy: Correlations with Clinical and Neurophysiological Data

    Directory of Open Access Journals (Sweden)

    Aristide Merola

    2016-01-01

    Full Text Available Objective. This cross-sectional study analyzes the pattern of ultrasound peripheral nerve alterations in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP and multifocal motor neuropathy (MMN at different stages of functional disability. Material and Methods. 22 CIDP and 10 MMN patients and a group of 70 healthy controls were evaluated with an ultrasound scan of the median, ulnar, peroneal, tibial, and sural nerves. Results were correlated with clinical disability scales and nerve conduction studies. Results. Patients with intermediate functional impairment showed relatively larger cross-sectional areas than subjects with either a milder (p<0.05 or more severe impairment (p<0.05, both in CIDP and in MMN. In addition, MMN was associated with greater side-to-side intranerve variability (p<0.05, while higher cross-sectional areas were observed in CIDP (p<0.05 and in nerve segments with predominantly demyelinating features (p<0.05. Higher CSA values were observed in nerves with demyelinating features versus axonal damage (p<0.05 for CIDP; p<0.05 for MMN. Discussion and Conclusions. Greater extent of quantitative and qualitative US alterations was observed in patients at intermediate versus higher functional disability and in nerves with demyelinating versus axonal damage. CIDP and MMN showed differential US aspects, with greater side-to-side intranerve variability in MMN and higher cross-sectional areas in CIDP.

  3. Hereditary optic neuropathies share a common mitochondrial coupling defect.

    Science.gov (United States)

    Chevrollier, Arnaud; Guillet, Virginie; Loiseau, Dominique; Gueguen, Naïg; de Crescenzo, Marie-Anne Pou; Verny, Christophe; Ferre, Marc; Dollfus, Hélène; Odent, Sylvie; Milea, Dan; Goizet, Cyril; Amati-Bonneau, Patrizia; Procaccio, Vincent; Bonneau, Dominique; Reynier, Pascal

    2008-06-01

    Hereditary optic neuropathies are heterogeneous diseases characterized by the degeneration of retinal ganglion cells leading to optic nerve atrophy and impairment of central vision. We found a common coupling defect of oxidative phosphorylation in fibroblasts of patients affected by autosomal dominant optic atrophy (mutations of OPA1), autosomal dominant optic atrophy associated with cataract (mutations of OPA3), and Leber's hereditary optic neuropathy, a disorder associated with point mutations of mitochondrial DNA complex I genes. Interestingly, the energetic defect was significantly more pronounced in Leber's hereditary optic neuropathy and autosomal dominant optic atrophy patients with a more complex phenotype, the so-called plus phenotype.

  4. The optic nerve head in hereditary optic neuropathies.

    Science.gov (United States)

    O'Neill, Evelyn C; Mackey, David A; Connell, Paul P; Hewitt, Alex W; Danesh-Meyer, Helen V; Crowston, Jonathan G

    2009-05-01

    Hereditary optic neuropathies are a prominent cause of blindness in both children and adults. The disorders in this group share many overlapping clinical characteristics, including morphological changes that occur at the optic nerve head. Accurate and prompt clinical diagnosis, supplemented with imaging when indicated, is essential for optimum management of the relevant optic neuropathy and appropriate counseling of the patient on its natural history. Patient history, visual field assessment, optic disc findings and imaging are the cornerstones of a correct diagnosis. This Review highlights the characteristic optic nerve head features that are common to the various hereditary optic neuropathies, and describes the features that enable the conditions to be differentiated.

  5. Neuropathy-Inducing Effects of Eribulin Mesylate Versus Paclitaxel in Mice with Preexisting Neuropathy

    OpenAIRE

    Wozniak, Krystyna M; Wu, Ying; Farah, Mohamed H.; Littlefield, Bruce A.; Nomoto, Kenichi; Barbara S Slusher

    2013-01-01

    Eribulin mesylate (E7389, INN:eribulin mesilate Halaven®) is a non-taxane microtubule dynamics inhibitor currently in clinical use for advanced breast cancer. Other microtubule-targeting agents for breast cancer, including paclitaxel and ixabepilone, display a common treatment dose-limiting toxicity of peripheral neuropathy (PN). In an earlier study, we found eribulin mesylate had a lower propensity to induce PN in mice than either paclitaxel or ixabepilone. In the current study, we compared ...

  6. Clinical features of diffuse axonal injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To analyze the mechanism of diffuse axonal injury (DAI) and study the relationship between DAI and brain concussion, brain contusion, and primary brain stem injury.Methods: The clinical data and iconographic characteristics of 56 patients with DAI were analyzed retrospectively.Results: Traffic accidents were the main cause of DAI. Among the 56 cases, 34 were injured for at least twice, and 71.43% of the patients were complicated with contusion.Conclusions: It is considered that DAI is a common pattern of primary brain injury, which is often underestimated. And DAI includes cerebral concussion and primary brain injury, and is often complicated by cerebral cortex contusion. Therefore, it is very simple and practical to divide primary brain injuries into local and diffuse injuries.

  7. Acrylamide induces accelerated endothelial aging in a human cell model.

    Science.gov (United States)

    Sellier, Cyril; Boulanger, Eric; Maladry, François; Tessier, Frédéric J; Lorenzi, Rodrigo; Nevière, Rémi; Desreumaux, Pierre; Beuscart, Jean-Baptiste; Puisieux, François; Grossin, Nicolas

    2015-09-01

    Acrylamide (AAM) has been recently discovered in food as a Maillard reaction product. AAM and glycidamide (GA), its metabolite, have been described as probably carcinogenic to humans. It is widely established that senescence and carcinogenicity are closely related. In vitro, endothelial aging is characterized by replicative senescence in which primary cells in culture lose their ability to divide. Our objective was to assess the effects of AAM and GA on human endothelial cell senescence. Human umbilical vein endothelial cells (HUVECs) cultured in vitro were used as model. HUVECs were cultured over 3 months with AAM or GA (1, 10 or 100 μM) until growth arrest. To analyze senescence, β-galactosidase activity and telomere length of HUVECs were measured by cytometry and semi-quantitative PCR, respectively. At all tested concentrations, AAM or GA reduced cell population doubling compared to the control condition (p < 0.001). β-galactosidase activity in endothelial cells was increased when exposed to AAM (≥10 μM) or GA (≥1 μM) (p < 0.05). AAM (≥10 μM) or GA (100 μM) accelerated telomere shortening in HUVECs (p < 0.05). In conclusion, in vitro chronic exposure to AAM or GA at low concentrations induces accelerated senescence. This result suggests that an exposure to AAM might contribute to endothelial aging.

  8. Idebenone for Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Gueven, N

    2016-03-01

    Idebenone is a rapidly absorbed, safe and well-tolerated drug and is currently the only clinically proven treatment option for Leber's hereditary optic neuropathy (LHON) patients. Idebenone (Raxone®) is approved by the European Medicines Agency for the treatment of LHON and has been available on the European market since 2015. Due to its molecular mode of action of bypassing the defective mitochondrial complex I, idebenone leads to improved energy supply and a functional recovery of retinal ganglion cells during the acute stage of the disease, thereby preventing further vision loss and promoting recovery of vision. Thus, commencing treatment shortly after the onset of symptoms is likely to have the best therapeutic effect, a hypothesis that is supported by the available clinical data. PMID:27186591

  9. Leber hereditary optic neuropathy in Australia.

    Science.gov (United States)

    Mackey, D A; Buttery, R G

    1992-08-01

    Leber hereditary optic neuropathy (LHON) presents with sudden onset of visual loss mainly in young adult males. LHON is not uncommon in Australia, accounting for 2% of invalid blind pensions. We have identified 20 unrelated families carrying mitochondrial DNA mutations associated with LHON and 135 of 291 individuals with documented LHON are currently alive in Australia. The mean age of onset of visual loss for males was 26 years and for females 27 years, with a range from six to 65 years. The mean risk of visual loss was 20% for males and 4% for females. There are over 1750 male and female carriers living in Australia who have not yet lost vision; 600 carriers are under 24 years of age. The expected number of new cases of blindness from LHON is three to four per year. PMID:1449769

  10. Idebenone for Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Gueven, N

    2016-03-01

    Idebenone is a rapidly absorbed, safe and well-tolerated drug and is currently the only clinically proven treatment option for Leber's hereditary optic neuropathy (LHON) patients. Idebenone (Raxone®) is approved by the European Medicines Agency for the treatment of LHON and has been available on the European market since 2015. Due to its molecular mode of action of bypassing the defective mitochondrial complex I, idebenone leads to improved energy supply and a functional recovery of retinal ganglion cells during the acute stage of the disease, thereby preventing further vision loss and promoting recovery of vision. Thus, commencing treatment shortly after the onset of symptoms is likely to have the best therapeutic effect, a hypothesis that is supported by the available clinical data.

  11. Hepatitis C virus infection, cryoglobulinemia, and peripheral neuropathy: a case report

    Directory of Open Access Journals (Sweden)

    Vigani A.G.

    2005-01-01

    Full Text Available Hepatitis C virus (HCV is essentially hepatotropic but its manifestations can extend beyond the liver. It can be associated with autoimmune diseases, such as mixed cryoglobulinemia, membranoproliferative glomerulonephritis, autoimmune thyroiditis, and lymphoproliferative disorders. The mechanisms that trigger these manifestations are not completely understood. We describe a 48-year-old man with chronic HCV infection (circulating HCV RNA and moderate hepatitis as indicated by liver biopsy, cryoglobulinemia, and sensory and motor peripheral neuropathy. The diagnosis of multineuropathy was confirmed by clinical examination and electromyographic tests. A nerve biopsy revealed an inflammatory infiltrate in the perineurial space and signs of demyelination and axonal degeneration. The patient had no improvement of neurological symptoms with the use of analgesics and neuro-modulators. He was then treated with interferon-alpha (3 million units subcutaneously, 3 times per week and ribavirin (500 mg orally, twice a day for 48 weeks. Six months after the end of therapy, the patient had sustained viral response (negative HCV RNA and remission of neurological symptoms, but cryoglobulins remained positive. A review of the literature on the pathogenesis and treatment of neurological manifestations associated with HCV infection is presented. This report underscores the need for a thorough evaluation of HCV-infected patients because of the possibility of extrahepatic manifestations. Antiviral treatment with interferon and ribavirin can be effective and should be considered in patients with neurological complications associated with HCV infection.

  12. Leber's Hereditary Optic Neuropathy-Gene Therapy: From Benchtop to Bedside

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    Rajeshwari D. Koilkonda

    2011-01-01

    Full Text Available Leber's hereditary optic neuropathy (LHON is a maternally transmitted disorder caused by point mutations in mitochondrial DNA (mtDNA. Most cases are due to mutations in genes encoding subunits of the NADH-ubiquinone oxidoreductase that is Complex I of the electron transport chain (ETC. These mutations are located at nucleotide positions 3460, 11778, or 14484 in the mitochondrial genome. The disease is characterized by apoplectic, bilateral, and severe visual loss. While the mutated mtDNA impairs generation of ATP by all mitochondria, there is only a selective loss of retinal ganglion cells and degeneration of optic nerve axons. Thus, blindness is typically permanent. Half of the men and 10% of females who harbor the pathogenic mtDNA mutation actually develop the phenotype. This incomplete penetrance and gender bias is not fully understood. Additional mitochondrial and/or nuclear genetic factors may modulate the phenotypic expression of LHON. In a population-based study, the mtDNA background of haplogroup J was associated with an inverse relationship of low-ATP generation and increased production of reactive oxygen species (ROS. Effective therapy for LHON has been elusive. In this paper, we describe the findings of pertinent published studies and discuss the controversies of potential strategies to ameliorate the disease.

  13. Sporadic hereditary motor and sensory neuropathies: Advances in the diagnosis using next generation sequencing technology.

    Science.gov (United States)

    Fallerini, Chiara; Carignani, Giulia; Capoccitti, Giorgio; Federico, Antonio; Rufa, Alessandra; Pinto, Anna Maria; Rizzo, Caterina Lo; Rossi, Alessandro; Mari, Francesca; Mencarelli, Maria Antonietta; Giannini, Fabio; Renieri, Alessandra

    2015-12-15

    Hereditary motor and sensory neuropathies (HMSN) are genetically heterogeneous disorders affecting peripheral motor and sensory functions. Many different pathogenic variants in several genes involved in the demyelinating, the axonal and the intermediate HMSN forms have been identified, for which all inheritance patterns have been described. The mutation screening currently available is based on Sanger sequencing and is time-consuming and relatively expensive due to the high number of genes involved and to the absence of mutational hot spots. To overcome these limitations, we have designed a custom panel for simultaneous sequencing of 28 HMSN-related genes. We have applied this panel to three representative patients with variable HMSN phenotype and uncertain diagnostic classifications. Using our NGS platform we rapidly identified three already described pathogenic heterozygous variants in MFN2, MPZ and DNM2 genes. Here we show that our pre-custom platform allows a fast, specific and low-cost diagnosis in sporadic HMSN cases. This prompt diagnosis is useful for providing a well-timed treatment, establishing a recurrence risk and preventing further investigations poorly tolerated by patients and expensive for the health system. Importantly, our study illustrates the utility and successful application of NGS to mutation screening of a Mendelian disorder with extreme locus heterogeneity.

  14. Hereditary motor and sensory neuropathies or Charcot-Marie-Tooth diseases: an update.

    Science.gov (United States)

    Tazir, Meriem; Hamadouche, Tarik; Nouioua, Sonia; Mathis, Stephane; Vallat, Jean-Michel

    2014-12-15

    Hereditary motor and sensory neuropathies (HMSN) or Charcot-Marie-Tooth (CMT) diseases are the most common degenerative disorders of the peripheral nervous system. However, the frequency of the different subtypes varies within distinct populations. Although more than seventy clinical and genetic forms are known to date, more than 80% of CMT patients in Western countries have genetic abnormalities associated with PMP22, MPZ, MFN2 and GJB1. Given the considerable genetic heterogeneity of CMT, we emphasize the interest of both clinical and pathological specific features such that focused genetic testing could be performed. In this regard, peripheral nerve lesions in GDAP1 mutations (AR CMT1A), such as mitochondrial abnormalities, have been newly demonstrated. Otherwise, while demyelinating autosomal recessive CMT used to be classified as CMT4 (A, B, C …), we propose a simplified classification such as AR CMT1 (A, B, C …), and AR CMT2 for axonal forms. Also, we stress that next generation sequencing techniques, now considered to be the most efficient methods of genetic testing in CMT, will be helpful in molecular diagnosis and research of new genes involved. Finally, while no effective therapy is known to date, ongoing new therapeutic trials such as PXT3003 (a low dose combination of the three already approved drugs baclofen, naltrexone, and D-sorbitol) give hopes for potential curative treatment.

  15. Peripheral motor neuropathy is associated with defective kinase regulation of the KCC3 cotransporter.

    Science.gov (United States)

    Kahle, Kristopher T; Flores, Bianca; Bharucha-Goebel, Diana; Zhang, Jinwei; Donkervoort, Sandra; Hegde, Madhuri; Hussain, Gulnaz; Duran, Daniel; Liang, Bo; Sun, Dandan; Bönnemann, Carsten G; Delpire, Eric

    2016-01-01

    Using exome sequencing, we identified a de novo mutation (c.2971A>G; T991A) in SLC12A6, the gene encoding the K(+)-Cl(-) cotransporter KCC3, in a patient with an early-onset, progressive, and severe peripheral neuropathy primarily affecting motor neurons. Normally, the WNK kinase-dependent phosphorylation of T(991) tonically inhibits KCC3; however, cell swelling triggers Thr(991) dephosphorylation to activate the transporter and restore cell volume. KCC3 T991A mutation in patient cells abolished Thr(991) phosphorylation, resulted in constitutive KCC3 activity, and compromised cell volume homeostasis. KCC3(T991A/T991A) mutant mice exhibited constitutive KCC3 activity and recapitulated aspects of the clinical, electrophysiological, and histopathological findings of the patient. These results suggest that the function of the peripheral nervous system depends on finely tuned, kinase-regulated KCC3 activity and implicate abnormal cell volume homeostasis as a previously unreported mechanism of axonal degeneration. PMID:27485015

  16. A case report of congenital sensory neuropathy with anhidrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hyong; Chang, Hae Soon; Han, Man Chung; Lee, Suck Hyun; Lee, Duk Yong [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1974-10-15

    Congenital sensory neuropathy with anhidrosis is rare disease and may be confused with other cause of pain insensitivity or indifference. Other cause of pain insensitivity include congenital indifference to pain, congenital sensory neuropathy, hereditary sensory radicular neuropathy, nonprogressive sensory radicular neuropathy, syringomyelia, and hysterical analgesia. It is hereditary disease which is transmitted with autosomal recessive trait. The patient is 8 years old Korean male with complaint of swelling and local heat on right knee joint. Generalized analgesia is noted on physical examination. The skin is dry and coarse with no evidence of sweating. Delayed motor development was noted on early children. Mental development is retarded. On past history, patient showed unpredictable rises of temperature, though the general condition remained good. Multiple painless fracture on right humerus and right metatasal bone was occurred. Rt.knee radiograms show marked swelling of soft tissue and periosteal calcification on distal femru,which are resemble with neurotrophic joint.

  17. Transcriptomic analyses of genes and tissues in inherited sensory neuropathies.

    Science.gov (United States)

    Sapio, Matthew R; Goswami, Samridhi C; Gross, Jacklyn R; Mannes, Andrew J; Iadarola, Michael J

    2016-09-01

    Inherited sensory neuropathies are caused by mutations in genes affecting either primary afferent neurons, or the Schwann cells that myelinate them. Using RNA-Seq, we analyzed the transcriptome of human and rat DRG and peripheral nerve, which contain sensory neurons and Schwann cells, respectively. We subdivide inherited sensory neuropathies based on expression of the mutated gene in these tissues, as well as in mouse TRPV1 lineage DRG nociceptive neurons, and across 32 human tissues from the Human Protein Atlas. We propose that this comprehensive approach to neuropathy gene expression leads to better understanding of the involved cell types in patients with these disorders. We also characterize the genetic "fingerprint" of both tissues, and present the highly tissue-specific genes in DRG and sciatic nerve that may aid in the development of gene panels to improve diagnostics for genetic neuropathies, and may represent specific drug targets for diseases of these tissues. PMID:27343803

  18. Prevalence of diabetic autonomic neuropathy measured by simple bedside tests

    DEFF Research Database (Denmark)

    Dyrberg, Torben Bech; Benn, Jette; Christiansen, J S;

    1981-01-01

    To investigate the prevalence of diabetic autonomic neuropathy, five simple bedside tests, beat-to-beat variation during quiet respiration, beat-to-beat variation during forced respiration, heart rate and blood pressure response to standing, heart rate response to exercise, and heart rate response....... The prevalence of diabetic autonomic neuropathy in the whole diabetic population indicated by abnormal response in beat-to-beat variation during forced respiration was 27%. Diabetic autonimic neuropathy increased in frequency with duration of disease. Patients with nephropathy or proliferative retinopathy had...... a significantly higher prevalence of diabetic autonomic neuropathy as indicated by abnormal beat-to-beat variation during forced respirations (p less than 0.01) than patients without these complications....

  19. Metabolic and cardiovascular responses to epinephrine in diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J; Richter, E; Madsbad, S;

    1987-01-01

    Norepinephrine-induced vasoconstriction, which is mediated by alpha-adrenergic receptors, is accentuated in patients with autonomic neuropathy. In contrast, responses mediated by beta-adrenergic receptors, including vasodilatation and metabolic changes, have not been evaluated in these patients. ...

  20. Hereditary peripheral neuropathies of childhood: an overview for clinicians.

    Science.gov (United States)

    Wilmshurst, Jo M; Ouvrier, Robert

    2011-11-01

    This review focuses on the "pure" hereditary peripheral neuropathies where peripheral nerve disease is the main manifestation and does not address neurodegenerative disorders associated with but not dominated by peripheral neuropathy. Aetiologies of childhood-onset peripheral neuropathies differ from those of adult-onset, with more inherited conditions, especially autosomal recessive. Charcot-Marie-Tooth disease is the commonest neuromuscular disorder. The genetic labels of CMT (Charcot-Marie-Tooth) disease types 1-4 are the preferred sub-type terms. Clinical presentations and molecular genetic heterogeneity of hereditary peripheral neuropathies are diverse. For most patients worldwide, diagnostic studies are limited to clinical assessment. Such markers which could be used to identify specific sub-types include presentation in early childhood, scoliosis, marked sensory involvement, respiratory compromise, upper limb involvement, visual or hearing impairment, pyramidal signs and mental retardation. These key markers may assist targeted genetic testing and aid in diagnosing children where DNA testing is not possible.

  1. Nutritional optic and peripheral neuropathy: a case report

    OpenAIRE

    Nightingale, Laura M; Paviour, Dominic C.

    2009-01-01

    Introduction The link between nutritional status and either optic or peripheral neuropathies is well established with tobacco, ethanol, deficiencies in thiamine, vitamin A, B12, B3 and B6 and protein-energy malnutrition all being causative. Case presentation We describe the case of a 32-year-old Afro-Caribbean of Jamaican origin presenting with blurred vision and a painful burning sensation in his feet. The clinical features were consistent with optic and peripheral neuropathy. Conclusions Th...

  2. Therapeutische Überlegungen bei sensomotorischer diabetischer Neuropathie

    OpenAIRE

    Bührlen M

    2013-01-01

    Der Begriff der sensomotorischen diabetischen Neuropathie beschreibt einen heterogenen Beschwerdekomplex, der auf einer diabetesbedingten Schädigung des peripheren Nervensystems beruht. Bis zu 50 % der Menschen mit Diabetes mellitus leiden im Verlauf ihrer Erkrankung an Symptomen einer sensomotorischen Neuropathie. Chronische Schmerzen, Dysund Parästhesien sowie die Komplikation des diabetischen Fußsyndroms stellen für die Betroffenen gravierende Folgen dar. Die Optimierung der met...

  3. The clinical spectrum of inflammatory-angiopathic neuropathy.

    OpenAIRE

    Harati, Y; Niakan, E

    1986-01-01

    Thirty-three patients with inflammatory-angiopathic neuropathy diagnosed by sural nerve biopsy, were investigated to determine the underlying disease. Twenty-six patients had symmetrical sensorimotor polyneuropathy and seven had mononeuropathy multiplex. An aetiology for inflammatory-angiopathic neuropathy was found in only eight patients: typical collagen vascular disease in five and malignant tumour in three. Sixteen patients received prednisone and/or immunosuppressive drug therapy and 12 ...

  4. Leber’s Inherited Optic Neuropathy: A Large Family

    Directory of Open Access Journals (Sweden)

    Taylan Pekoz

    2012-04-01

    Full Text Available Leber's hereditary optic neuropathy characterized by loss of central vision is often seen in men and a maternally inherited disease. Here, admitted to our clinic with complaints of unilateral visual loss was diagnosed as Leber's hereditary optic neuropathy which was confirmed by the presence of a mutation at 3460G>A position. [Cukurova Med J 2012; 37(2.000: 121-124

  5. Hereditary sensory autonomic neuropathy and anaesthesia - a case report

    Directory of Open Access Journals (Sweden)

    Nandini Dave

    2007-01-01

    Full Text Available The hereditary sensory and autonomic neuropathies are a rare group of disorders characterized by progressive loss of function that predominantly affects the peripheral sensory nerves. Autonomic dysfunction is present to a variable degree and can have several implications for anaesthesia. We report the case of a patient with Hereditary sensory and autonomic neuropathy who was posted for a below knee amputation and discuss the anaesthesia management.

  6. Oxidative Injury and Neuropathy in Diabetes and Impaired Glucose Tolerance

    OpenAIRE

    Russell, James W.; Berent-Spillson, Alison; Vincent, Andrea M.; Freimann, Catherine L.; Sullivan, Kelli A; Eva L Feldman

    2008-01-01

    Clinical studies suggest that impaired glucose tolerance (IGT) is associated with the development of neuropathy. The aim of the current study was to determine if neuropathy developed in the female Zucker Diabetic Fatty (ZDF) rat, an animal model of IGT and type 2 diabetes. The ZDF rat develops impaired glucose tolerance (IGT) when fed a control diet, and frank diabetes when fed a high fat diet. Following 10 weeks of hyperglycemia, sensory nerve action potentials (SNAP) and compound motor acti...

  7. Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Anusha; Srinivasan, Sivasubramanian [Khoo Teck Puat Hospital, Singapore (Singapore)

    2012-09-15

    We read with great interest, the case report on ischemic optic neuropathy (1). We would like to add a few points concerning the blood supply of the optic nerve and the correlation with the development of post-operative ischemic neuropathy. Actually, the perioperative or post-operative vision loss (postoperative ischemic neuropathy) is most likely due to ischemic optic neuropathy. Ischemic optic neuropathy (2) is classified as an anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). This classification is based on the fact that blood supply (2) to the anterior segment of the optic nerve (part of the optic nerve in the scleral canal and the optic disc) is supplied by short posterior ciliary vessels or anastamotic ring branches around the optic nerve. The posterior part of the optic canal is relatively less perfused, and is supplied by ophthalmic artery and central fibres are perfused by a central retinal artery. So, in the post-operative period, the posterior part of the optic nerve is more vulnerable for ischemia, especially, after major surgeries (3), one of the theories being hypotension or anaemia (2) and resultant decreased perfusion. The onset of PION is slower than the anterior ischemic optic neuropathy. AION on the other hand, is usually spontaneous (idiopathic) or due to arteritis, and is usually sudden in its onset. The reported case is most likely a case of PION. The role of imaging, especially the diffusion weighted magnetic resonance imaging, is very important because the ophthalmoscopic findings in early stages of PION is normal, and it may delay the diagnosis. On the other hand, edema of the disc is usually seen in the early stages of AION.

  8. Intra-axonal myosin and actin in nerve regeneration.

    Science.gov (United States)

    McQuarrie, Irvine G; Lund, Linda M

    2009-10-01

    A focused review of sciatic nerve regeneration in the rat model, based on research conducted by the authors, is presented. We examine structural proteins carried distally in the axon by energy-requiring motor enzymes, using protein chemistry and molecular biology techniques in combination with immunohistochemistry. Relevant findings from other laboratories are cited and discussed. The general conclusion is that relatively large amounts of actin and tubulin are required to construct a regenerating axon and that these materials mainly originate in the parent axon. The motor enzymes that carry these proteins forward as macromolecules include kinesin and dynein but probably also include myosin. PMID:19927086

  9. Axon guidance and neuronal migration research in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Proper migration of neuronal somas and axonal growth cones to designated locations in the developing brain is essential for the assembly of functional neuronal circuits.Rapid progress in research of axon guidance and neuronal migration has been made in the last twenty years.Chinese researchers began their exploration in this field ten years ago and have made significant contributions in clarifying the signal transduction of axon guidance and neuronal migration.Several unique experimental approaches,including the migration assay of single isolated neurons in response to locally delivered guidance cues,have been developed by Chinese neuroscientists to investigate the molecular machinery underlying these guidance events.

  10. Potential risk factors for diabetic neuropathy: a case control study

    Directory of Open Access Journals (Sweden)

    Nooraei Mahdi

    2005-12-01

    Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

  11. Axon diameter mapping in crossing fibers with diffusion MRI

    DEFF Research Database (Denmark)

    Zhang, Hui; Dyrby, Tim B; Alexander, Daniel C

    2011-01-01

    tissue than measures derived from diffusion tensor imaging. Most existing techniques for axon diameter mapping assume a single axon orientation in the tissue model, which limits their application to only the most coherently oriented brain white matter, such as the corpus callosum, where the single...... orientation assumption is a reasonable one. However, fiber crossings and other complex configurations are widespread in the brain. In such areas, the existing techniques will fail to provide useful axon diameter indices for any of the individual fiber populations. We propose a novel crossing fiber tissue...... of the technique by establishing reasonable axon diameter indices in the crossing region at the interface of the cingulum and the corpus callosum....

  12. Internodal function in normal and regenerated mammalian axons

    DEFF Research Database (Denmark)

    Moldovan, M; Krarup, C

    2007-01-01

    human nerves. CONCLUSION: The data suggest that persistently shorter regenerated internodes lead to increased Na+/K+-pump activity in response to increased Na+ entry during conduction. This may impair axonal function during prolonged repetitive activity and drain the energy reserves of the axons.......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 regenerated internodes remain persistently short though this abnormality did not seem to influence recovery in conduction. It remains unclear to which extent abnormalities in axonal function itself may contribute to the poor outcome of nerve regeneration. METHODS: We review experimental evidence indicating...

  13. RGM is a repulsive guidance molecule for retinal axons

    DEFF Research Database (Denmark)

    Monnier, Philippe P; Sierra, Ana; Macchi, Paolo;

    2002-01-01

    Axons rely on guidance cues to reach remote targets during nervous system development. A well-studied model system for axon guidance is the retinotectal projection. The retina can be divided into halves; the nasal half, next to the nose, and the temporal half. A subset of retinal axons, those from...... the temporal half, is guided by repulsive cues expressed in a graded fashion in the optic tectum, part of the midbrain. Here we report the cloning and functional characterization of a membrane-associated glycoprotein, which we call RGM (repulsive guidance molecule). This molecule shares no sequence homology...... with known guidance cues, and its messenger RNA is distributed in a gradient with increasing concentration from the anterior to posterior pole of the embryonic tectum. Recombinant RGM at low nanomolar concentration induces collapse of temporal but not of nasal growth cones and guides temporal retinal axons...

  14. Structural plasticity of axon terminals in the adult.

    Science.gov (United States)

    Gogolla, Nadine; Galimberti, Ivan; Caroni, Pico

    2007-10-01

    There is now conclusive evidence for widespread ongoing structural plasticity of presynaptic boutons and axon side-branches in the adult brain. The plasticity complements that of postsynaptic spines, but axonal plasticity samples larger volumes of neuropil, and has a larger impact on circuit remodeling. Axons from distinct neurons exhibit unique ratios of stable (t1/2>9 months) and dynamic (t1/2 5-20 days) boutons, which persist as spatially intermingled subgroups along terminal arbors. In addition, phases of side-branch dynamics mediate larger scale remodeling guided by synaptogenesis. The plasticity is most pronounced during critical periods; its patterns and outcome are controlled by Hebbian mechanisms and intrinsic neuronal factors. Novel experience, skill learning, life-style, and age can persistently modify local circuit structure through axonal structural plasticity.

  15. Changes in prefrontal axons may disrupt the network in autism

    OpenAIRE

    Zikopoulos, Basilis; Barbas, Helen

    2010-01-01

    Neural communication is disrupted in autism by unknown mechanisms. Here we examined whether in autism there are changes in axons, which are the conduit for neural communication. We investigated single axons and their ultrastructure in the white matter of post-mortem human brain tissue below the anterior cingulate cortex (ACC), orbitofrontal (OFC), and lateral (LPFC) prefrontal cortices, which are associated with attention, social interactions, and emotions and have been consistently implicate...

  16. 6-Sulphated chondroitins have a positive influence on axonal regeneration.

    Directory of Open Access Journals (Sweden)

    Rachel Lin

    Full Text Available Chondroitin sulphate proteoglycans (CSPGs upregulated in the glial scar inhibit axon regeneration via their sulphated glycosaminoglycans (GAGs. Chondroitin 6-sulphotransferase-1 (C6ST-1 is upregulated after injury leading to an increase in 6-sulphated GAG. In this study, we ask if this increase in 6-sulphated GAG is responsible for the increased inhibition within the glial scar, or whether it represents a partial reversion to the permissive embryonic state dominated by 6-sulphated glycosaminoglycans (GAGs. Using C6ST-1 knockout mice (KO, we studied post-injury changes in chondroitin sulphotransferase (CSST expression and the effect of chondroitin 6-sulphates on both central and peripheral axon regeneration. After CNS injury, wild-type animals (WT showed an increase in mRNA for C6ST-1, C6ST-2 and C4ST-1, but KO did not upregulate any CSSTs. After PNS injury, while WT upregulated C6ST-1, KO showed an upregulation of C6ST-2. We examined regeneration of nigrostriatal axons, which demonstrate mild spontaneous axon regeneration in the WT. KO showed many fewer regenerating axons and more axonal retraction than WT. However, in the PNS, repair of the median and ulnar nerves led to similar and normal levels of axon regeneration in both WT and KO. Functional tests on plasticity after the repair also showed no evidence of enhanced plasticity in the KO. Our results suggest that the upregulation of 6-sulphated GAG after injury makes the extracellular matrix more permissive for axon regeneration, and that the balance of different CSs in the microenvironment around the lesion site is an important factor in determining the outcome of nervous system injury.

  17. Axonal maintenance, glia, exosomes, and heat shock proteins

    OpenAIRE

    Michael Tytell; Lasek, Raymond J.; Harold Gainer

    2016-01-01

    Of all cellular specializations, the axon is especially distinctive because it is a narrow cylinder of specialized cytoplasm called axoplasm with a length that may be orders of magnitude greater than the diameter of the cell body from which it originates. Thus, the volume of axoplasm can be much greater than the cytoplasm in the cell body. This fact raises a logistical problem with regard to axonal maintenance. Many of the components of axoplasm, such as soluble proteins and cytoskeleton, are...

  18. Axon-glia interaction and membrane traffic in myelin formation

    Directory of Open Access Journals (Sweden)

    Robin eWhite

    2014-01-01

    Full Text Available In vertebrate nervous systems myelination of neuronal axons has evolved to increase conduction velocity of electrical impulses with minimal space and energy requirements. Myelin is formed by specialised glial cells which ensheath axons with a lipid-rich insulating membrane. Myelination is a multi-step process initiated by axon-glia recognition triggering glial polarisation followed by targeted myelin membrane expansion and compaction. Thereby, a myelin sheath of complex subdomain structure is established. Continuous communication between neurons and glial cells is essential for myelin maintenance and axonal integrity. A diverse group of diseases, from multiple sclerosis to schizophrenia, have been linked to malfunction of myelinating cells reflecting the physiological importance of the axon-glial unit. This review describes the mechanisms of axonal signal integration by oligodendrocytes emphasising the central role of the Src-family kinase Fyn during CNS myelination. Furthermore, we discuss myelin membrane trafficking with particular focus on endocytic recycling and the control of PLP (proteolipid protein transport by SNARE proteins. Finally, PLP mistrafficking is considered in the context of myelin diseases.

  19. Spectrum of peripheral neuropathies associated with surgical interventions; A neurophysiological assessment

    LENUS (Irish Health Repository)

    Saidha, Shiv

    2010-04-19

    Abstract Background We hypothesized that a wide range of surgical procedures may be complicated by neuropathies, not just in close proximity but also remote from procedural sites. The aim of this study was to classify post-operative neuropathies and the procedures associated with them. Methods We retrospectively identified 66 patients diagnosed with post-procedure neuropathies between January 2005 and June 2008. We reviewed their referral cards and medical records for patient demographics, information on procedures, symptoms, as well as clinical and neurophysiological findings. Results Thirty patients (45.4%) had neuropathies remote from procedural sites and 36 patients (54.5%) had neuropathies in close proximity to procedural sites. Half of the remote neuropathies (15\\/30) developed following relatively short procedures. In 27% of cases (8\\/30) remote neuropathies were bilateral. Seven patients developed neuropathies remote from operative sites following hip arthroplasties (7\\/30: 23.3%), making hip arthroplasty the most common procedure associated with remote neuropathies. Sciatic neuropathies due to hip arthroplasty (12\\/36, 33.3%) accounted for the majority of neuropathies occurring in close proximity to operative sites. Five medial cutaneous nerve of forearm neuropathies occurred following arterio-venous fistula (AVF) formation. Conclusions An array of surgical procedures may be complicated by neuropathy. Almost half of post-procedure neuropathies occur remote from the site of procedure, emphasizing the need to try to prevent not just local, but also remote neuropathies. Mechanical factors and patient positioning should be considered in the prevention of post-operative neuropathies. There is a possible association between AVF formation and medial cutaneous nerve of forearm neuropathy, which requires further study for validation.

  20. Spectrum of peripheral neuropathies associated with surgical interventions; A neurophysiological assessment

    Directory of Open Access Journals (Sweden)

    Mullins Gerard

    2010-04-01

    Full Text Available Abstract Background We hypothesized that a wide range of surgical procedures may be complicated by neuropathies, not just in close proximity but also remote from procedural sites. The aim of this study was to classify post-operative neuropathies and the procedures associated with them. Methods We retrospectively identified 66 patients diagnosed with post-procedure neuropathies between January 2005 and June 2008. We reviewed their referral cards and medical records for patient demographics, information on procedures, symptoms, as well as clinical and neurophysiological findings. Results Thirty patients (45.4% had neuropathies remote from procedural sites and 36 patients (54.5% had neuropathies in close proximity to procedural sites. Half of the remote neuropathies (15/30 developed following relatively short procedures. In 27% of cases (8/30 remote neuropathies were bilateral. Seven patients developed neuropathies remote from operative sites following hip arthroplasties (7/30: 23.3%, making hip arthroplasty the most common procedure associated with remote neuropathies. Sciatic neuropathies due to hip arthroplasty (12/36, 33.3% accounted for the majority of neuropathies occurring in close proximity to operative sites. Five medial cutaneous nerve of forearm neuropathies occurred following arterio-venous fistula (AVF formation. Conclusions An array of surgical procedures may be complicated by neuropathy. Almost half of post-procedure neuropathies occur remote from the site of procedure, emphasizing the need to try to prevent not just local, but also remote neuropathies. Mechanical factors and patient positioning should be considered in the prevention of post-operative neuropathies. There is a possible association between AVF formation and medial cutaneous nerve of forearm neuropathy, which requires further study for validation.

  1. Frequency of sensory motor neuropathy in type 2 diabetics

    International Nuclear Information System (INIS)

    To determine the frequency of sensory motor neuropathy in type 2 diabetics at the time of presentation to the hospital. The study was conducted at Medical Unit-1, Jinnah Postgraduate Medical Center, Karachi, from November 2005 to April 2006. Patients of different ages and either gender with history of confirmed diabetes for ten years and above, on regular follow up were included. Those with non-diabetic causes of hyperglycemia or neuropathy were excluded. Relevant features like age, gender, treatment, symptoms , signs, nerve conduction study (NCS) results, duration of Diabetes mellitus (DM), fasting blood sugar (FBS) and serum values of glycosylated hemoglobin (HB1Ac) were recorded. Out of a total of 300 patients, there were 111 female and 189 male patients. Mean age was 58 +- 11.23 years. Mean duration of diabetes was 13.6+-5.48 years. One hundred and twenty three patients had symptoms of neuropathy. Clinical examination revealed mixed sensory and motor signs in 135 (45%) patients. Nerve conduction studies revealed abnormalities in 159 (53%) patients. Among patients having an abnormal NCS, the fasting blood glucose (FBS) was 120mg/dl in 147 (91%) patients. The glycosylated hemoglobin ranged from 4-15% with mean of 8.1% and standard deviation of 2.5%. This showed significant association (p <0.001) of peripheral neuropathy with abnormal FBS, HB1Ac and duration of diabetes. NCS diagnosed the neuropathy in more than half of the total number of patients, including both symptomatic and asymptomatic patients. Majority of the patients revealed symmetrical and a mixed type (motor and sensory) polyneuropathy. This shows that nerve conduction may not be concordant with the clinical signs and symptoms. NCS detects neuropathy much earlier, before it becomes evident clinically. The neuropathy is associated with abonromal fasting blood sugar, HBIAC and duration of diabetes. (author)

  2. Ultrastructural observation of effect of moderate hypothermia on axonal damage in an animal model of diffuse axonal injury

    Institute of Scientific and Technical Information of China (English)

    孙晓川; 唐文渊; 郑履平

    2002-01-01

    Objective: To investigate the effect of moderate hypothermia on responses of axonal cytoskeleton to axonal injury in the acute stage of injury. Methods: Of fifteen adult guinea pigs, twelve animals were subjected to stretch injury to the right optic nerves and divided into the normothermic group (n=6) in which the animal's core temperature was maintained at 36.0-37.5℃ and the hypothermia group (n=6) in which the core temperature was reduced to 32.0-32.5℃ after stretch injury. Remaining three animals sustained no injury to the right optic nerves and served as control group. Half of injured animals (n=3) of either normothermic group or hypothermic group were killed at either 2 hours or 4 hours after injury. The ultrastructural changes of axonal cytoskeleton of the right optic nerve fibers from the animals were examined under a transmission electron microscope and analyzed by quantitative analysis with a computer image analysis system. Results: At 2 hours after stretch injury, there was a significant reduction in the mean number of microtubules (P<0.001), and a significant increase in the mean intermicrotubule spacing (P<0.05 or P<0.01) in axons of all sizes in normothermic animals. The mean number of neurofilaments also decreased statistically (P<0.01) in large and medium subgroups of axons in the same experimental group at 2 hours. By 4 hours, the large subgroup of axons in normothermic animals still demonstrated a significant decline in the mean number of microtubules (P<0.01) and an increase in the mean intermicrotubule spacing (P<0.05), while the medium and small subgroups of axons displayed a significant increase in the mean number of neurofilaments (P<0.05) and reduction in the mean interneurofilament spacing (P<0.05). On the contrary, either the mean number of microtubules and the mean intermicrotubule spacing, or the mean number of neurofilaments and interneurofilament spacing in axons of all sizes in hypothermic stretch-injured animals was not

  3. Toxic optic neuropathy: An unusual cause

    Directory of Open Access Journals (Sweden)

    Hema L Ramkumar

    2014-01-01

    Full Text Available A 60-year-old woman with a history of chronic alcoholism and tobacco use presented with the complaint of a painless decrease in vision in both eyes. She lost vision first in the left eye then in the right eye. She admitted consuming at least one 16 ounce bottle of over the counter mouthwash daily and denied consumption of any other alcohols, methanol, or antifreeze. She stated that her vision had been continuing to deteriorate in both eyes. Her best-corrected visual acuity was 4/200 in each eye. Color vision was nil in each eye. Her pupils were sluggish bilaterally, and her optic discs were flat and hyperemic with peripapillary hemorrhages. Her visual fields revealed central scotomas bilaterally. The magnetic resonance imaging of the brain and lumbar puncture were within normal limits. Antinuclear antibody, human leukocyte antigen-B27 genotyping, and B12 were normal; serum thiamine was low. While continuing to ingest mouthwash, her vision decreased to count fingers at 2 feet, and maculopapillary bundle pallor developed. She was started on folate and thiamine supplementation. Once she discontinued mouthwash, her vision improved to 20/400 bilaterally, and her central scotomas improved. This case demonstrates an alcohol-induced toxic optic neuropathy from mouthwash ingestion with some visual recovery after discontinuation of the offending agent.

  4. [Designation criteria for Leber's hereditary optic neuropathy].

    Science.gov (United States)

    Nakamura, Makoto; Mimura, Osamu; Wakakura, Masato; Inatani, Masaru; Nakazawa, Toru; Shiraga, Fumio

    2015-05-01

    Designation criteria for Leber's hereditary optic neuropathy (LHON) have been established by a working group for retino-choroidal and optic atrophy funded by the Ministry of Health, Labor, and Welfare (MHLW) of Japan in collaboration with the Japanese Neuro-ophthalmology Society. The criteria are composed of three major symptoms and three ancillary test findings. According to the number and the combination of these symptoms and findings, subjects are classified into definite, probable, and possible LHON cases and asymptomatic carriers. The major symptoms include bilateral involvement with a time-lag, a papillomacular bundle atrophy, both characteristic optic disc findings at the acute phase. In the ancillary testings, mitochondrial DNA mutations specific for LHON are detailed with a table listing the mutation loci being attached. To enhance readers' understanding of description of the major symptoms and ancillary test findings, explanatory remarks on 11 parameters are supplemented. The establishment of the criteria facilitates epidemiological survey of LHON by MHLW and contributes to improvement of welfare for patients with LHON in Japan.

  5. Traumatic Optic Neuropathy – A Conundrum

    Science.gov (United States)

    Selvaraj, Vinoth Kanna; Devanathan, Vasudevan

    2016-01-01

    Visual impairment following head injury may be an enigma especially if the onset of symptoms were to be few days after the actual trauma and the bias arising out of the initial normal ophthalmological examination is not neutralised by unbiased repeated formal clinical evaluation aided with electrophysiology. We report and discuss here a 32-year-old lady with delayed onset of indirect traumatic visual loss with anaemia who failed to improve after blood transfusion but improved immediately following steroid therapy seven days after trauma. Though steroids have not been shown to have a significant contribution on outcomes following Traumatic optic neuropathy, this report rekindles its role in delayed progressive visual loss following head trauma and the need to re-analyse the role of steroids in patients with delayed progressive visual disturbance following head injury excluding those with acute onset symptoms in view of different pathologies in both these presentations. This paper also highlights potential mechanisms for the two major types of presentation. PMID:27134913

  6. CURRENT THERAPEUTIC STRATEGY IN DIABETIC NEUROPATHY

    Directory of Open Access Journals (Sweden)

    Kaur Parminder

    2012-03-01

    Full Text Available Diabetic neuropathy (DN is a group of multifactorial disorder in diabetic patients, which affects neuronal function of the whole body and is accompanied by nephropathy and angiopathy. Its prevalence increases with duration of diabetes and hyperglycaemia which can induce oxidative stress resulting in activation of multiple pathways which can damage the neurons alone or in combination. Symptoms of DN are prominent early in type 2 than in type 1. Neuropathic pain which can occur continuously only in 20-30% of the patients, otherwise pain was not reported. The drugs available for DN were not able to cure the disease but provide only symptomatic relief and were also associated with major side effects. Current therapy provided in this review alleviates the symptoms in clinical trials and thus will be recommended in order to stop the progression of disease. Despite the recent understanding regarding the pathogenesis of disease, till date only two drugs were approved by FDA for DN, α-lipoic acid is available in several countries and epalrestat in Japan, which is also associated with side effects but they are tolerable.

  7. Phenotypic variability of TRPV4 related neuropathies

    Science.gov (United States)

    Evangelista, Teresinha; Bansagi, Boglarka; Pyle, Angela; Griffin, Helen; Douroudis, Konstantinos; Polvikoski, Tuomo; Antoniadi, Thalia; Bushby, Kate; Straub, Volker; Chinnery, Patrick F.; Lochmüller, Hanns; Horvath, Rita

    2015-01-01

    Mutations in the transient receptor potential vanilloid 4 (TRPV4) gene have been associated with autosomal dominant skeletal dysplasias and peripheral nervous system syndromes (PNSS). PNSS include Charcot–Marie–Tooth disease (CMT) type 2C, congenital spinal muscular atrophy and arthrogryposis and scapuloperoneal spinal muscular atrophy. We report the clinical, electrophysiological and muscle biopsy findings in two unrelated patients with two novel heterozygous missense mutations in the TRPV4 gene. Whole exome sequencing was carried out on genomic DNA using Illumina TruseqTM 62Mb exome capture. Patient 1 harbours a de novo c.805C > T (p.Arg269Cys) mutation. Clinically, this patient shows signs of both scapuloperoneal spinal muscular atrophy and skeletal dysplasia. Patient 2 harbours a novel c.184G > A (p.Asp62Asn) mutation. While the clinical phenotype is compatible with CMT type 2C with the patient's muscle harbours basophilic inclusions. Mutations in the TRPV4 gene have a broad phenotypic variability and disease severity and may share a similar pathogenic mechanism with Heat Shock Protein related neuropathies. PMID:25900305

  8. Strategies and Methods for the Treatment of Diabetic Neuropathy Using Integrative Chinese and Western Medicine

    Institute of Scientific and Technical Information of China (English)

    HENG Xian-pei

    2008-01-01

    @@ Diabetic neuropathy (DN) is the most common metabolic neuropathy in clinics, not only in diabetes patients (>60%), but also in pre-diabetic (8%) and normal persons (5%)(1). Its pathogenesis has not been fully understood up to now.

  9. Effectiveness of combined alprostadil and pancreatic kininogenas in treating gerontal diabetic peripheral neuropathy

    Institute of Scientific and Technical Information of China (English)

    张玉

    2013-01-01

    Objective To observe the clinical effectiveness of alprostadil combined with pancreatic kininogenas in the treatment of gerontal diabetic peripheral neuropathy.Methods Totally 90 gerontal patients with diabetic peripheral neuropathy were randomly divided into three

  10. The role of serum methylglyoxal on diabetic peripheral and cardiovascular autonomic neuropathy

    DEFF Research Database (Denmark)

    Hansen, C. S.; Jensen, T.M.; Jensen, J S;

    2015-01-01

    AIMS: Cardiovascular autonomic neuropathy and diabetic peripheral neuropathy are common diabetic complications and independent predictors of cardiovascular disease. The glucose metabolite methylglyoxal has been suggested to play a causal role in the pathogeneses of diabetic peripheral neuropathy...... and possibly diabetic cardiovascular autonomic neuropathy. The aim of this study was to investigate the cross-sectional association between serum methylglyoxal and diabetic peripheral neuropathy and cardiovascular autonomic neuropathy in a subset of patients in the ADDITION-Denmark study with short-term screen......-detected Type 2 diabetes (duration ~ 5.8 years). METHODS: The patients were well controlled with regard to HbA(1c), lipids and blood pressure. Cardiovascular autonomic neuropathy was assessed by measures of resting heart rate variability and cardiovascular autonomic reflex tests. Diabetic peripheral neuropathy...

  11. Speech identification and cortical potentials in individuals with auditory neuropathy

    Directory of Open Access Journals (Sweden)

    Vanaja CS

    2008-03-01

    Full Text Available Abstract Background Present study investigated the relationship between speech identification scores in quiet and parameters of cortical potentials (latency of P1, N1, and P2; and amplitude of N1/P2 in individuals with auditory neuropathy. Methods Ten individuals with auditory neuropathy (five males and five females and ten individuals with normal hearing in the age range of 12 to 39 yr participated in the study. Speech identification ability was assessed for bi-syllabic words and cortical potentials were recorded for click stimuli. Results Results revealed that in individuals with auditory neuropathy, speech identification scores were significantly poorer than that of individuals with normal hearing. Individuals with auditory neuropathy were further classified into two groups, Good Performers and Poor Performers based on their speech identification scores. It was observed that the mean amplitude of N1/P2 of Poor Performers was significantly lower than that of Good Performers and those with normal hearing. There was no significant effect of group on the latency of the peaks. Speech identification scores showed a good correlation with the amplitude of cortical potentials (N1/P2 complex but did not show a significant correlation with the latency of cortical potentials. Conclusion Results of the present study suggests that measuring the cortical potentials may offer a means for predicting perceptual skills in individuals with auditory neuropathy.

  12. Focal and multifocal diabetic neuropathies Neuropatia diabética focal e multifocal

    OpenAIRE

    Gérard Said

    2007-01-01

    Diabetic neuropathy is the most common neuropathy in industrialized countries, with a remarkable range of clinical manifestations. The vast majority of the patients with clinical diabetic neuropathy have a distal symmetrical form that progress following a fiber-length dependent pattern, with predominant sensory and autonomic manifestations. This pattern of neuropathy is associated with a progressive distal axonopathy. Patients are exposed to trophic changes in the feet, pains and autonomic di...

  13. Diabetic neuropathies: update on definitions, diagnostic criteria, estimation of severity, and treatments

    DEFF Research Database (Denmark)

    Tesfaye, Solomon; Boulton, Andrew J M; Dyck, Peter J;

    2010-01-01

    Preceding the joint meeting of the 19th annual Diabetic Neuropathy Study Group of the European Association for the Study of Diabetes (NEURODIAB) and the 8th International Symposium on Diabetic Neuropathy in Toronto, Canada, 13-18 October 2009, expert panels were convened to provide updates...... on classification, definitions, diagnostic criteria, and treatments of diabetic peripheral neuropathies (DPNs), autonomic neuropathy, painful DPNs, and structural alterations in DPNs....

  14. Wnt5a regulates midbrain dopaminergic axon growth and guidance.

    Directory of Open Access Journals (Sweden)

    Brette D Blakely

    Full Text Available During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM the cues that guide dopaminergic (DA axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway. Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a-/- mice, where fasciculation of the medial forebrain bundle (MFB as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance.

  15. Regulation of Microtubule Dynamics in Axon Regeneration: Insights from C. elegans [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Ngang Heok Tang

    2016-04-01

    Full Text Available The capacity of an axon to regenerate is regulated by its external environment and by cell-intrinsic factors. Studies in a variety of organisms suggest that alterations in axonal microtubule (MT dynamics have potent effects on axon regeneration. We review recent findings on the regulation of MT dynamics during axon regeneration, focusing on the nematode Caenorhabditis elegans. In C. elegans the dual leucine zipper kinase (DLK promotes axon regeneration, whereas the exchange factor for Arf6 (EFA-6 inhibits axon regeneration. Both DLK and EFA-6 respond to injury and control axon regeneration in part via MT dynamics. How the DLK and EFA-6 pathways are related is a topic of active investigation, as is the mechanism by which EFA-6 responds to axonal injury. We evaluate potential candidates, such as the MT affinity-regulating kinase PAR-1/MARK, in regulation of EFA-6 and axonal MT dynamics in regeneration.

  16. Coordinated motor neuron axon growth and neuromuscular synaptogenesis are promoted by CPG15 in vivo.

    Science.gov (United States)

    Javaherian, Ashkan; Cline, Hollis T

    2005-02-17

    We have used in vivo time-lapse two-photon imaging of single motor neuron axons labeled with GFP combined with labeling of presynaptic vesicle clusters and postsynaptic acetylcholine receptors in Xenopus laevis tadpoles to determine the dynamic rearrangement of individual axon branches and synaptogenesis during motor axon arbor development. Control GFP-labeled axons are highly dynamic during the period when axon arbors are elaborating. Axon branches emerge from sites of synaptic vesicle clusters. These data indicate that motor neuron axon elaboration and synaptogenesis are concurrent and iterative. We tested the role of Candidate Plasticity Gene 15 (CPG15, also known as Neuritin), an activity-regulated gene that is expressed in the developing motor neurons in this process. CPG15 expression enhances the development of motor neuron axon arbors by promoting neuromuscular synaptogenesis and by increasing the addition of new axon branches. PMID:15721237

  17. Plasma osteoprotegerin concentrations in peripheral sensory neuropathy in Type 1 and Type 2 diabetic patients

    DEFF Research Database (Denmark)

    Nybo, M; Poulsen, M K; Grauslund, J;

    2010-01-01

    Osteoprotegerin (OPG) has been linked to different diabetes complications, including cardiovascular disease, and new findings have indicated a specific role in diabetic peripheral neuropathy, but the exact mechanism is unknown. To investigate a possible association between OPG and diabetic...... peripheral sensory neuropathy, we therefore analysed plasma OPG in Type 1 and Type 2 diabetic patients with and without peripheral neuropathy....

  18. UTILITY OF F WAVE MINIMAL LATENCY FOR DIAGNOSIS OF DIABETIC NEUROPATHY

    Directory of Open Access Journals (Sweden)

    Gargate

    2014-12-01

    Full Text Available BACKGROUND: Diabetes mellitus (DM is a metabolic disorder which has become a major public health problem worldwide. Its commonest complication is diabetic peripheral neuropathy (DPN. DPN is characterized by combining axonal loss and demyelinating sensory motor peripheral neuropathy. To investigate this condition nerve conduction studies with determination of latency and velocity are commonly used as they are considered to be the most sensitive, reliable, non-invasive and objective means. DPN is believed to affect mainly distal nerve segments. However, it has been recently reported that F-wave study in diabetic patients is very reliable. AIM: Aim of the present study was to find out whether F-wave minimal latency (FWML is having more sensitivity compared to motor nerve conduction study for diagnosis of DPN. METHODS AND MATERIALS: Motor and sensory nerve conduction and F-wave studies of upper and lower extremity nerves were carried out bilaterally in 60 clinically diagnosed patients with Type II diabetes mellitus. These parameters were also studied in 45 age matched controls. RESULTS: Sensitivity for distal motor latency (DML was 53.33% in median, 26.31% in ulnar, 25.8% in peroneal and 41.17% in tibial nerves. Sensitivity for motor amplitude- compound muscle action potential (CMAP was 56.66% in the median, 66.66% in ulnar, 80.64% in personnel and 72.54% in tibial nerves. Sensitivity for motor conduction velocity (MNCV was 50% in the median, 47.36% in ulnar, 77.41% in personnel and 72.55% in tibial nerves. Sensitivity for distal sensory latency (DSL was 37.97% in the median, 23.8% in ulnar, 41.5% in sural nerves. Sensitivity for sensory amplitude (SNAP was 8.01% in the median, 64.28% in ulnar and 60.37% in sural nerves. Sensitivity for sensory conduction velocity (SNCV was 40.5% in median, 26.19% in ulnar and 58.49% in Sural nerves. Prolonged FWMLs were found in 73.87% of median, 69% of ulnar, 72.72% of peroneal and 68.96% of tibial nerves. The

  19. Phenotyping animal models of diabetic neuropathy: a consensus statement of the diabetic neuropathy study group of the EASD (Neurodiab).

    Science.gov (United States)

    Biessels, G J; Bril, V; Calcutt, N A; Cameron, N E; Cotter, M A; Dobrowsky, R; Feldman, E L; Fernyhough, P; Jakobsen, J; Malik, R A; Mizisin, A P; Oates, P J; Obrosova, I G; Pop-Busui, R; Russell, J W; Sima, A A; Stevens, M J; Schmidt, R E; Tesfaye, S; Veves, A; Vinik, A I; Wright, D E; Yagihashi, S; Yorek, M A; Ziegler, D; Zochodne, D W

    2014-06-01

    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 understanding of each area, gold standards (if applicable) for assessments of function, improvements of existing techniques, and utility of known and exploratory biomarkers. The research opportunities in each area were outlined, providing a possible roadmap for future studies. The meeting concluded with a discussion on the merits and limitations of a unified approach to phenotyping rodent models of diabetic neuropathy and a consensus formed on the definition of the minimum criteria required for establishing the presence of the disease. A neuropathy phenotype in rodents was defined as the presence 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 toward the therapeutic efficacy of drug interventions.

  20. Is there a relationship between oral health and diabetic neuropathy?

    Science.gov (United States)

    Borgnakke, Wenche S; Anderson, Patricia F; Shannon, Carol; Jivanescu, Anca

    2015-11-01

    Diabetic neuropathy is the most common microvascular complication of diabetes mellitus with high morbidity and mortality, and low quality of life. It has a broad spectrum of clinical forms, although distal symmetrical polyneuropathy is the most prevalent. Several oral complications including burning mouth syndrome, dry mouth, and impairment of the senses taste and smell are less-known manifestations of diabetic neuropathy and often overlooked. Periodontitis, tooth loss, and temporomandibular joint dysfunction may be also present in these patients and are equally debilitating. Periodontitis was declared the sixth complication of diabetes in 1993 and may contribute to poor glucose control. Hence, periodontitis and diabetes mutually and adversely affect each other. This review summarizes the available body of scientific literature that discusses oral manifestations in patients with diabetic neuropathy and identifies important areas where more research is needed. PMID:26374570

  1. Glaucoma progression associated with Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Nucci, Carlo; Martucci, Alessio; Mancino, Raffaele; Cerulli, Luciano

    2013-02-01

    The purpose of this article is to describe a case of open-angle glaucoma progression associated with Leber's hereditary optic neuropathy. Single case analysis method is used. A 53-year-old woman with a previous diagnosis of glaucoma presented with progressive visual field loss. Complete ophthalmological examination and blood tests were negative for other concomitant diseases. Genetic counseling revealed mitochondrial DNA mutation compatible with the diagnosis of Leber's hereditary optic neuropathy. In conclusion, the case describes the concomitant occurrence of open-angle glaucoma and Leber's optic neuropathy. We hypothesize that the two diseases may have a cumulative effect on oxidative stress and retinal ganglion cell death with the consequent rapid progression of visual impairment. Screening for mitochondrial DNA mutations may be requested in patients with glaucoma who, despite pharmacologically controlled intraocular pressure, show rapid progression of the disease.

  2. Antiretroviral therapy-induced Leber’s hereditary optic neuropathy

    Directory of Open Access Journals (Sweden)

    Anand Moodley

    2014-05-01

    Full Text Available Optic neuropathy in HIV-infected patients results from the HIV infection itself, post-infectious auto-immune disease, opportunistic infections and drugs. Nucleoside reverse transcriptase inhibitors (NRTIs such as zidovudine and stavudine have known mitochondrial toxicity and can cause mitochondrial myopathies, neuropathies, hyperlactataemia, and can induce mitochondrial genetic disorders. Individuals with the mutation for Leber’s hereditary optic neuropathy (LHON, a mitochondrial disorder, are usually asymptomatic but develop visual loss when exposed to external triggers such as smoking. We report on two HIV-infected patients with LHON mutations (m.14484T>C and m.11778G>A who developed profound visual loss with antiretroviral therapy. We postulate that the phenotypic expression of LHON in these genetically predisposed individuals was triggered by NRTI drugs lamivudine and tenofovir when used in combination, despite their relatively weak mitochondrial toxic effects. 

  3. Bilateral optic neuropathy in a patient with familial amyloidotic polyneuropathy

    DEFF Research Database (Denmark)

    Hamann, Steffen; Jensen, Peter Koch; Fledelius, Hans Callø

    2013-01-01

    Amyloidogenic transthyretin (ATTR)-related familial amyloidotic polyneuropathy (FAP) is an autosomal-dominant hereditary disease characterised by slowly progressive peripheral sensorimotor and autonomic neuropathy and tissue involvement of the heart, kidneys and central nervous system. Secondary...... ATTR Val30Met mutation. After 11 years of ophthalmic follow-up best-corrected visual acuity was 20/100 in his seeing eye, which further had visual field findings suggestive of optic neuropathy. This was also the diagnosis underlying the preceding insidious full loss of vision in the fellow eye......, with colour Doppler imaging to support an ischaemic aetiology. To our knowledge, this is the first report of ischaemic optic neuropathy in this familial amyloid disorder....

  4. HIV-related neuropathy: current perspectives

    Directory of Open Access Journals (Sweden)

    Schütz SG

    2013-09-01

    Full Text Available Sonja G Schütz, Jessica Robinson-Papp Department of Neurology, Mount Sinai School of Medicine, New York, NY, USA Abstract: Distal symmetric polyneuropathy (DSP related to human immunodeficiency virus (HIV is one of the most common neurologic complications of HIV, possibly affecting as many as 50% of all individuals infected with HIV. Two potentially neurotoxic mechanisms have been proposed to play a crucial role in the pathogenesis of HIV DSP: neurotoxicity resulting from the virus and its products; as well as adverse neurotoxic effects of medications used in the treatment of HIV. Clinically, HIV DSP is characterized by a combination of signs and symptoms that include decreased deep tendon reflexes at the ankles and decreased sensation in the distal extremities as well as paresthesias, dysesthesias, and pain in a symmetric stocking–glove distribution. These symptoms are generally static or slowly progressive over time, and depending on the severity, may interfere significantly with the patient's daily activities. In addition to the clinical picture, nerve conduction studies and skin biopsies are often pursued to support the diagnosis of HIV DSP. Anticonvulsants, antidepressants, topical agents, and nonspecific analgesics may help relieve neuropathic pain. Specifically, gabapentin, lamotrigine, pregabalin, amitriptyline, duloxetine, and high-dose topical capsaicin patches have been used in research and clinical practice. Further research is needed to elucidate the pathogenesis of HIV DSP, thus facilitating the development of novel treatment strategies. This review discusses the epidemiology, pathophysiology, clinical findings, diagnosis, and management of DSP in the setting of HIV. Keywords: neuropathy, human immunodeficiency virus, acquired immunodeficiency syndrome, AIDS, distal symmetric polyneuropathy, DSP, pain

  5. A novel technique using hydrophilic polymers to promote axonal fusion

    Institute of Scientific and Technical Information of China (English)

    Ravinder Bamba; D Colton Riley; Nathaniel D Kelm; Mark D Does; Richard D Dortch; Wesley P hTayer

    2016-01-01

    The management of traumatic peripheral nerve injury remains a considerable concern for clinicians. With minimal innovations in surgical technique and a limited number of specialists trained to treat peripheral nerve injury, outcomes of surgical intervention have been unpredictable. The inability to manipulate the pathophysiology of nerve injury (i.e., Wallerian degeneration) has left scientists and clinicians depending on the slow and lengthy process of axonal regeneration (~1 mm/day). When axons are severed, the endings undergo calcium-mediated plasmalemmal sealing, which limits the ability of the axon to be primarily re-paired. Polythethylene glycol (PEG) in combination with a bioengineered process overcomes the inability to fuse axons. The mechanism for PEG axonal fusion is not clearly understood, but multiple studies have shown that a providing a calcium-free environment is essential to the process known as PEG fusion. The proposed mechanism is PEG-induced lipid bilayer fusion by removing the hydration barrier surrounding the axolemma and reducing the activation energy required for membrane fusion to occur. This review highlights PEG fusion, its past and current studies, and future directions in PEG fusion.

  6. Highly effective photonic cue for repulsive axonal guidance.

    Directory of Open Access Journals (Sweden)

    Bryan J Black

    Full Text Available In vivo nerve repair requires not only the ability to regenerate damaged axons, but most importantly, the ability to guide developing or regenerating axons along paths that will result in functional connections. Furthermore, basic studies in neuroscience and neuro-electronic interface design require the ability to construct in vitro neural circuitry. Both these applications require the development of a noninvasive, highly effective tool for axonal growth-cone guidance. To date, a myriad of technologies have been introduced based on chemical, electrical, mechanical, and hybrid approaches (such as electro-chemical, optofluidic flow and photo-chemical methods. These methods are either lacking in desired spatial and temporal selectivity or require the introduction of invasive external factors. Within the last fifteen years however, several attractive guidance cues have been developed using purely light based cues to achieve axonal guidance. Here, we report a novel, purely optical repulsive guidance technique that uses low power, near infrared light, and demonstrates the guidance of primary goldfish retinal ganglion cell axons through turns of up to 120 degrees and over distances of ∼90 µm.

  7. Subtypes of GABAergic neurons project axons in the neocortex

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    Shigeyoshi Higo

    2009-11-01

    Full Text Available γ-aminobutyric acid (GABAergic neurons in the neocortex have been regarded as interneurons and speculated to modulate the activity of neurons locally. Recently, however, several experiments revealed that neuronal nitric oxide synthase (nNOS-positive GABAergic neurons project cortico-cortically with long axons. In this study, we illustrate Golgi-like images of the nNOS-positive GABAergic neurons using a nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d reaction and follow the emanating axon branches in cat brain sections. These axon branches projected cortico-cortically with other non-labeled arcuate fibers, contra-laterally via the corpus callosum and anterior commissure. The labeled fibers were not limited to the neocortex but found also in the fimbria of the hippocampus. In order to have additional information on these GABAergic neuron projections, we investigated green fluorescent protein (GFP-labeled GABAergic neurons in GAD67-Cre knock-in / GFP Cre-reporter mice. GFP-labeled axons emanate densely, especially in the fimbria, a small number in the anterior commissure, and very sparsely in the corpus callosum. These two different approaches confirm that not only nNOS-positive GABAergic neurons but also other subtypes of GABAergic neurons project long axons in the cerebral cortex and are in a position to be involved in information processing.

  8. Functional complexity of the axonal growth cone: a proteomic analysis.

    Directory of Open Access Journals (Sweden)

    Adriana Estrada-Bernal

    Full Text Available The growth cone, the tip of the emerging neurite, plays a crucial role in establishing the wiring of the developing nervous system. We performed an extensive proteomic analysis of axonal growth cones isolated from the brains of fetal Sprague-Dawley rats. Approximately 2000 proteins were identified at ≥ 99% confidence level. Using informatics, including functional annotation cluster and KEGG pathway analysis, we found great diversity of proteins involved in axonal pathfinding, cytoskeletal remodeling, vesicular traffic and carbohydrate metabolism, as expected. We also found a large and complex array of proteins involved in translation, protein folding, posttranslational processing, and proteasome/ubiquitination-dependent degradation. Immunofluorescence studies performed on hippocampal neurons in culture confirmed the presence in the axonal growth cone of proteins representative of these processes. These analyses also provide evidence for rough endoplasmic reticulum and reveal a reticular structure equipped with Golgi-like functions in the axonal growth cone. Furthermore, Western blot revealed the growth cone enrichment, relative to fetal brain homogenate, of some of the proteins involved in protein synthesis, folding and catabolism. Our study provides a resource for further research and amplifies the relatively recently developed concept that the axonal growth cone is equipped with proteins capable of performing a highly diverse range of functions.

  9. Role of A3 adenosine receptor in diabetic neuropathy.

    Science.gov (United States)

    Yan, Heng; Zhang, Enshui; Feng, Chang; Zhao, Xin

    2016-10-01

    Neuropathy is the most common diabetic complication. Although the A1 and A2A adenosine receptors are important pharmacological targets in alleviating diabetic neuropathy, the role of the A3 adenosine receptor remains unknown. Because the A3 adenosine receptor regulates pain induced by chronic constriction injury or chemotherapy, its stimulation might also attenuate diabetic neuropathy. This study examines the effects of systemic treatment with the A3 adenosine receptor agonist 1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-β-d-ribofuranuronamide (IB-MECA) on diabetic neuropathy and explores the putative mechanisms underlying its pharmacological effects. We show that IB-MECA alleviated mechanical hyperalgesia and thermal hypoalgesia in mice 2 weeks but not 4 weeks after streptozocin (STZ) treatment. Furthermore, IB-MECA prevented the reduction in sciatic motor nerve conduction velocity and sensory nerve conduction velocity in diabetic mice 2 weeks but not 4 weeks after STZ treatment. Similarly, IB-MECA inhibited the activation of nuclear factor-κB and decreased the generation of tumor necrosis factor-α in the spinal cord of mice 2 weeks but not 4 weeks after STZ treatment. These phenomena were associated with reduction of A3 adenosine receptor expression in the spinal cord after long-term diabetes. Our results suggest that the A3 adenosine receptor plays a critical role in regulating diabetic neuropathy and that reduction in A3 adenosine receptor expression/function might contribute to the progression of diabetic neuropathy. © 2016 Wiley Periodicals, Inc.

  10. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    Directory of Open Access Journals (Sweden)

    Anders Victor ePetersen

    2015-10-01

    Full Text Available The axon initial segment (AIS is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recoding of extracellular local field potentials and whole-cell patch-clamp recording of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from the brain.

  11. Successful amelioration of mitochondrial optic neuropathy using the yeast NDI1 gene in a rat animal model.

    Directory of Open Access Journals (Sweden)

    Mathieu Marella

    Full Text Available BACKGROUND: Leber's hereditary optic neuropathy (LHON is a maternally inherited disorder with point mutations in mitochondrial DNA which result in loss of vision in young adults. The majority of mutations reported to date are within the genes encoding the subunits of the mitochondrial NADH-quinone oxidoreductase, complex I. Establishment of animal models of LHON should help elucidate mechanism of the disease and could be utilized for possible development of therapeutic strategies. METHODOLOGY/PRINCIPAL FINDINGS: We established a rat model which involves injection of rotenone-loaded microspheres into the optic layer of the rat superior colliculus. The animals exhibited the most common features of LHON. Visual loss was observed within 2 weeks of rotenone administration with no apparent effect on retinal ganglion cells. Death of retinal ganglion cells occurred at a later stage. Using our rat model, we investigated the effect of the yeast alternative NADH dehydrogenase, Ndi1. We were able to achieve efficient expression of the Ndi1 protein in the mitochondria of all regions of retinal ganglion cells and axons by delivering the NDI1 gene into the optical layer of the superior colliculus. Remarkably, even after the vision of the rats was severely impaired, treatment of the animals with the NDI1 gene led to a complete restoration of the vision to the normal level. Control groups that received either empty vector or the GFP gene had no effects. CONCLUSIONS/SIGNIFICANCE: The present study reports successful manifestation of LHON-like symptoms in rats and demonstrates the potential of the NDI1 gene therapy on mitochondrial optic neuropathies. Our results indicate a window of opportunity for the gene therapy to be applied successfully after the onset of the disease symptoms.

  12. Nonarteritic ischemic optic neuropathy developed after capsular block syndrome

    Directory of Open Access Journals (Sweden)

    Volkan Hurmeric

    2014-01-01

    Full Text Available A 65-year-old man developed capsular block syndrome in the early postoperative period, following phacoemulsification surgery. After neodymium-doped yttrium aluminum garnet (Nd:YAG laser anterior capsulotomy, the intraocular pressure remained elevated for 4 days despite antiglaucomatous medication. On the postoperative fifth day, nonarteritic ischemic optic neuropathy was diagnosed. To the best of our knowledge, this is the first report of a case with nonarteritic ischemic optic neuropathy associated with early postoperative capsular block syndrome after phacoemulsification surgery.

  13. Involvement of SARA in Axon and Dendrite Growth.

    Science.gov (United States)

    Arias, Cristina Isabel; Siri, Sebastián Omar; Conde, Cecilia

    2015-01-01

    SARA (Smad Anchor for Receptor Activation) plays a crucial role in Rab5-mediated endocytosis in cell lines localizing to early endosomes where it regulates morphology and function. Here, we analyzed the role of SARA during neuronal development and tested whether it functions as a regulator of endocytic trafficking of selected axonal and membrane proteins. Suppression of SARA perturbs the appearance of juxtanuclear endocytic recycling compartments and the neurons show long axons with large growth cones. Furthermore, surface distribution of the cell adhesion molecule L1 in axons and the fusion of vesicles containing transferring receptor (TfR) in dendrites were increased in neurons where SARA was silenced. Conversely, SARA overexpression generated large early endosomes and reduced neurite outgrowth. Taken together, our findings suggest a significant contribution of SARA to key aspects of neuronal development, including neurite formation. PMID:26405814

  14. Neurofilament proteins in axonal regeneration and neurodegenerative diseases

    Institute of Scientific and Technical Information of China (English)

    Haitao Wang; Minfei Wu; Chuanjun Zhan; Enyuan Ma; Maoguang Yang; Xiaoyu Yang; Yingpu Li

    2012-01-01

    Neurofilament protein is a component of the mature neuronal cytoskeleton, and it interacts with the zygosome, which is mediated by neurofilament-related proteins. Neurofilament protein regulates enzyme function and the structure of linker proteins. In addition, neurofilament gene expression plays an important role in nervous system development. Previous studies have shown that neurofilament gene transcriptional regulation is crucial for neurofilament protein expression, especially in axonal regeneration and degenerative diseases. Post-transcriptional regulation increased neurofilament protein gene transcription during axonal regeneration, ultimately resulting in a pattern of neurofilament protein expression. An expression imbalance of post-transcriptional regulatory proteins and other disorders could lead to amyotrophic lateral sclerosis or other neurodegenerative diseases. These findings indicated that after transcription, neurofilament protein regulated expression of related proteins and promoted regeneration of damaged axons, suggesting that regulation disorders could lead to neurodegenerative diseases.

  15. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    Energy Technology Data Exchange (ETDEWEB)

    Menelaou, Evdokia; Paul, Latoya T. [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Perera, Surangi N. [Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States); Svoboda, Kurt R., E-mail: svobodak@uwm.edu [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States)

    2015-04-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  16. Localization and expression of ciliary neurotrophic factor (CNTF) in postmortem sciatic nerve from patients with motor neuron disease and diabetic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.A. [Univ. Medical Center, New Orleans, LA (United States); Gross, L.; Wittrock, D.A.; Windebank, A.J. [Mayo Clinic, Rochester, MN (United States)

    1996-08-01

    Ciliary neurotrophic factor (CNTF) is thought to play an important role in the maintenance of the mature motor system. The factor is found most abundantly in myelinating Schwann cells in the adult sciatic nerve. Lack of neuronal growth factors has been proposed as one possible etiology of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Growth factor replacement therapies are currently being evaluated as a treatment for motor neuron disease. In this report we determined whether the expression of CNTF in sciatic nerve differed in patients with motor neuron disease compared to controls or patients with another form of axonopathy. We identified 8 patients (7 with ALS and 1 with SMA) with motor neuron disease and 6 patients with diabetic motor neuropathy who had autopsy material available. Immunoperoxidase staining showed reduced CNTF expression in nerves of patients with motor neuron disease but not in patients with diabetic motor neuropathy. Decreased CNTF appears be associated with primary motor neuron disease rather than a generalized process of axon loss. This result supports suggestions that CNTF deficiency may be an important factor in the development of motor neuron disease. 20 refs., 4 figs., 1 tab.

  17. Axon-glial interactions in the central nervous system

    OpenAIRE

    Butt, Arthur; Bay, Virginia

    2011-01-01

    Axon-glial interactions are critical for brain information transmission and processing. In the CNS, this is a function of the major types of glia – astrocytes, oligodendrocytes and novel NG2-glia. This special issue of the Journal of Anatomy comprises contributions arising from a symposium entitled ‘Axon-glial interactions in the CNS’, held at the University of Portsmouth, UK in July 2010. The aim of the special issue is to bring together an international group of experts to demonstrate the c...

  18. Metabolite profile of a mouse model of Charcot-Marie-Tooth type 2D neuropathy: implications for disease mechanisms and interventions.

    Science.gov (United States)

    Bais, Preeti; Beebe, Kirk; Morelli, Kathryn H; Currie, Meagan E; Norberg, Sara N; Evsikov, Alexei V; Miers, Kathy E; Seburn, Kevin L; Guergueltcheva, Velina; Kremensky, Ivo; Jordanova, Albena; Bult, Carol J; Burgess, Robert W

    2016-01-01

    Charcot-Marie-Tooth disease encompasses a genetically heterogeneous class of heritable polyneuropathies that result in axonal degeneration in the peripheral nervous system. Charcot-Marie-Tooth type 2D neuropathy (CMT2D) is caused by dominant mutations in glycyl tRNA synthetase (GARS). Mutations in the mouse Gars gene result in a genetically and phenotypically valid animal model of CMT2D. How mutations in GARS lead to peripheral neuropathy remains controversial. To identify putative disease mechanisms, we compared metabolites isolated from the spinal cord of Gars mutant mice and their littermate controls. A profile of altered metabolites that distinguish the affected and unaffected tissue was determined. Ascorbic acid was decreased fourfold in the spinal cord of CMT2D mice, but was not altered in serum. Carnitine and its derivatives were also significantly reduced in spinal cord tissue of mutant mice, whereas glycine was elevated. Dietary supplementation with acetyl-L-carnitine improved gross motor performance of CMT2D mice, but neither acetyl-L-carnitine nor glycine supplementation altered the parameters directly assessing neuropathy. Other metabolite changes suggestive of liver and kidney dysfunction in the CMT2D mice were validated using clinical blood chemistry. These effects were not secondary to the neuromuscular phenotype, as determined by comparison with another, genetically unrelated mouse strain with similar neuromuscular dysfunction. However, these changes do not seem to be causative or consistent metabolites of CMT2D, because they were not observed in a second mouse Gars allele or in serum samples from CMT2D patients. Therefore, the metabolite 'fingerprint' we have identified for CMT2D improves our understanding of cellular biochemical changes associated with GARS mutations, but identification of efficacious treatment strategies and elucidation of the disease mechanism will require additional studies.

  19. Metabolite profile of a mouse model of Charcot–Marie–Tooth type 2D neuropathy: implications for disease mechanisms and interventions

    Science.gov (United States)

    Bais, Preeti; Beebe, Kirk; Morelli, Kathryn H.; Currie, Meagan E.; Norberg, Sara N.; Evsikov, Alexei V.; Miers, Kathy E.; Seburn, Kevin L.; Guergueltcheva, Velina; Kremensky, Ivo; Jordanova, Albena; Bult, Carol J.

    2016-01-01

    ABSTRACT Charcot–Marie–Tooth disease encompasses a genetically heterogeneous class of heritable polyneuropathies that result in axonal degeneration in the peripheral nervous system. Charcot–Marie–Tooth type 2D neuropathy (CMT2D) is caused by dominant mutations in glycyl tRNA synthetase (GARS). Mutations in the mouse Gars gene result in a genetically and phenotypically valid animal model of CMT2D. How mutations in GARS lead to peripheral neuropathy remains controversial. To identify putative disease mechanisms, we compared metabolites isolated from the spinal cord of Gars mutant mice and their littermate controls. A profile of altered metabolites that distinguish the affected and unaffected tissue was determined. Ascorbic acid was decreased fourfold in the spinal cord of CMT2D mice, but was not altered in serum. Carnitine and its derivatives were also significantly reduced in spinal cord tissue of mutant mice, whereas glycine was elevated. Dietary supplementation with acetyl-L-carnitine improved gross motor performance of CMT2D mice, but neither acetyl-L-carnitine nor glycine supplementation altered the parameters directly assessing neuropathy. Other metabolite changes suggestive of liver and kidney dysfunction in the CMT2D mice were validated using clinical blood chemistry. These effects were not secondary to the neuromuscular phenotype, as determined by comparison with another, genetically unrelated mouse strain with similar neuromuscular dysfunction. However, these changes do not seem to be causative or consistent metabolites of CMT2D, because they were not observed in a second mouse Gars allele or in serum samples from CMT2D patients. Therefore, the metabolite ‘fingerprint’ we have identified for CMT2D improves our understanding of cellular biochemical changes associated with GARS mutations, but identification of efficacious treatment strategies and elucidation of the disease mechanism will require additional studies. PMID:27288508

  20. Metabolite profile of a mouse model of Charcot–Marie–Tooth type 2D neuropathy: implications for disease mechanisms and interventions

    Directory of Open Access Journals (Sweden)

    Preeti Bais

    2016-07-01

    Full Text Available Charcot–Marie–Tooth disease encompasses a genetically heterogeneous class of heritable polyneuropathies that result in axonal degeneration in the peripheral nervous system. Charcot–Marie–Tooth type 2D neuropathy (CMT2D is caused by dominant mutations in glycyl tRNA synthetase (GARS. Mutations in the mouse Gars gene result in a genetically and phenotypically valid animal model of CMT2D. How mutations in GARS lead to peripheral neuropathy remains controversial. To identify putative disease mechanisms, we compared metabolites isolated from the spinal cord of Gars mutant mice and their littermate controls. A profile of altered metabolites that distinguish the affected and unaffected tissue was determined. Ascorbic acid was decreased fourfold in the spinal cord of CMT2D mice, but was not altered in serum. Carnitine and its derivatives were also significantly reduced in spinal cord tissue of mutant mice, whereas glycine was elevated. Dietary supplementation with acetyl-L-carnitine improved gross motor performance of CMT2D mice, but neither acetyl-L-carnitine nor glycine supplementation altered the parameters directly assessing neuropathy. Other metabolite changes suggestive of liver and kidney dysfunction in the CMT2D mice were validated using clinical blood chemistry. These effects were not secondary to the neuromuscular phenotype, as determined by comparison with another, genetically unrelated mouse strain with similar neuromuscular dysfunction. However, these changes do not seem to be causative or consistent metabolites of CMT2D, because they were not observed in a second mouse Gars allele or in serum samples from CMT2D patients. Therefore, the metabolite ‘fingerprint’ we have identified for CMT2D improves our understanding of cellular biochemical changes associated with GARS mutations, but identification of efficacious treatment strategies and elucidation of the disease mechanism will require additional studies.

  1. Networks of Polarized Actin Filaments in the Axon Initial Segment Provide a Mechanism for Sorting Axonal and Dendritic Proteins

    Directory of Open Access Journals (Sweden)

    Kaori Watanabe

    2012-12-01

    Full Text Available Trafficking of proteins specifically to the axonal or somatodendritic membrane allows neurons to establish and maintain polarized compartments with distinct morphology and function. Diverse evidence suggests that an actin-dependent vesicle filter within the axon initial segment (AIS plays a critical role in polarized trafficking; however, no distinctive actin-based structures capable of comprising such a filter have been found within the AIS. Here, using correlative light and scanning electron microscopy, we visualized networks of actin filaments several microns wide within the AIS of cortical neurons in culture. Individual filaments within these patches are predominantly oriented with their plus ends facing toward the cell body, consistent with models of filter selectivity. Vesicles carrying dendritic proteins are much more likely to stop in regions occupied by the actin patches than in other regions, indicating that the patches likely prevent movement of dendritic proteins to the axon and thereby act as a vesicle filter.

  2. Membrane potential dynamics of axons in cultured hippocampal neurons probed by second-harmonic-generation imaging

    Science.gov (United States)

    Nuriya, Mutsuo; Yasui, Masato

    2010-03-01

    The electrical properties of axons critically influence the nature of communication between neurons. However, due to their small size, direct measurement of membrane potential dynamics in intact and complex mammalian axons has been a challenge. Furthermore, quantitative optical measurements of axonal membrane potential dynamics have not been available. To characterize the basic principles of somatic voltage signal propagation in intact axonal arbors, second-harmonic-generation (SHG) imaging is applied to cultured mouse hippocampal neurons. When FM4-64 is applied extracellularly to dissociated neurons, whole axonal arbors are visualized by SHG imaging. Upon action potential generation by somatic current injection, nonattenuating action potentials are recorded in intact axonal arbors. Interestingly, however, both current- and voltage-clamp recordings suggest that nonregenerative subthreshold somatic voltage changes at the soma are poorly conveyed to these axonal sites. These results reveal the nature of membrane potential dynamics of cultured hippocampal neurons, and further show the possibility of SHG imaging in physiological investigations of axons.

  3. Spinal MRI of vincristine neuropathy mimicking Guillain-Barre syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yun Woo; Yoon, Hye-Kyung; Cho, Jae Min [Department of Radiology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul 135-710 (Korea); Sung, Ki Woong [Department of Paediatrics, Samsung Medical Centre, Seoul 135-710 (Korea)

    2003-11-01

    A 4.3-year-old girl with acute leukaemia, who was being treated with chemotherapy (including vincristine), developed paraplegia. Spinal MRI showed diffusely enhancing nerve roots on contrast-enhanced images. Spinal fluid analysis showed a normal protein level. Vincristine neuropathy mimicking Guillain-Barre syndrome is thought to be the cause of the MRI abnormalities. (orig.)

  4. Neurolysis and myocutaneous flap for radiation induced brachial plexus neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Hirachi, Kazuhiko; Minami, Akio; Kato, Hiroyuki; Nishio, Yasuhiko [Hokkaido Univ., Sapporo (Japan). School of Medicine; Ohnishi, Nobuki

    1998-11-01

    Surgical treatment for radiation induced brachial plexus neuropathy is difficult. We followed 9 patients of radiation induced brachial plexus neuropathy who were surgically treated with neurolysis and myocutaneous flap coverage. Their ages ranged from 29 to 72 years old. Their diagnoses were breast cancer in 6 patients, lingual cancer in 1, thyroid cancer in 1 and malignant lymphoma in 1. Total dose of radiation ranged from 44 to 240 Gy. Interval from radiation therapy to our surgery ranged from 1 to 18 years (mean 6.7 years). Chief complaints were dysesthesia in 9 patients, motor weakness in 7 patients and dullach in scar formation of radiated skin in 7 patients. Preoperative neural functions were slight palsy in 1, moderate palsy in 5 and complete palsy in 3. In surgical treatment, neurolysis of the brachial plexus was done and it was covered by latissimus dorsi myocutaneous flap. We evaluated about dysesthesia and motor recovery after treatment for neuropathy. Follow up periods ranged from 1 to 11 years (average in 5 years). Dysesthesia improved in 6 patients and got worse in 3 patients. Motor weakness recovered in only 2 patients and got worse in 7 patients. From our results, intolerable dysesthesia which was first complaint of these patients improved. But motor function had not recovered. Our treatment was thought to be effective for extraneural factor like an compression neuropathy by scar formation and poor vascularity. But it was not effective for intraneural damage by radiation therapy. (author)

  5. Reappraising entrapment neuropathies--mechanisms, diagnosis and management.

    Science.gov (United States)

    Schmid, Annina B; Nee, Robert J; Coppieters, Michel W

    2013-12-01

    The diagnosis of entrapment neuropathies can be difficult because symptoms and signs often do not follow textbook descriptions and vary significantly between patients with the same diagnosis. Signs and symptoms which spread outside of the innervation territory of the affected nerve or nerve root are common. This Masterclass provides insight into relevant mechanisms that may account for this extraterritorial spread in patients with entrapment neuropathies, with an emphasis on neuroinflammation at the level of the dorsal root ganglia and spinal cord, as well as changes in subcortical and cortical regions. Furthermore, we describe how clinical tests and technical investigations may identify these mechanisms if interpreted in the context of gain or loss of function. The management of neuropathies also remains challenging. Common treatment strategies such as joint mobilisation, neurodynamic exercises, education, and medications are discussed in terms of their potential to influence certain mechanisms at the site of nerve injury or in the central nervous system. The mechanism-oriented approach for this Masterclass seems warranted given the limitations in the current evidence for the diagnosis and management of entrapment neuropathies. PMID:24008054

  6. PERIPHERAL NEUROPATHY ELECTROPHYSIOLOGICAL SCREENING IN CHILDREN WITH CELIAC DISEASE

    Directory of Open Access Journals (Sweden)

    Şedat IŞIKAY

    2015-06-01

    Full Text Available Background The involvement of the peripheral nervous system in children with celiac disease is particularly rare. Objective The aim of this study was to assess the need for neurophysiological testing in celiac disease patients without neurological symptoms in order to detect early subclinical neuropathy and its possible correlations with clinical and demographic characteristics. Methods Two hundred and twenty consecutive children with celiac disease were screened for neurological symptoms and signs, and those without symptoms or signs were included. Also, patients with comorbidities associated with peripheral neuropathy or a history of neurological disease were excluded. The remaining 167 asymptomatic patients as well as 100 control cases were tested electro-physiologically for peripheral nervous system diseases. Motor nerve conduction studies, including F-waves, were performed for the median, ulnar, peroneal, and tibial nerves, and sensory nerve conduction studies were performed for the median, ulnar, and sural nerves with H reflex of the soleus muscle unilaterally. All studies were carried out using surface recording electrodes. Normative values established in our laboratory were used. Results Evidence for subclinical neuropathy was not determined with electrophysiological studies in any of the participants. Conclusion In this highly selective celiac disease group without any signs, symptoms as well as the predisposing factors for polyneuropathy, we did not determine any cases with neuropathy. With these results we can conclude that in asymptomatic cases with celiac disease electrophysiological studies are not necessary. However, larger studies with the electrophysiological studies performed at different stages of disease at follow-ups are warranted.

  7. Peripheral Neuropathy in Military Aircraft Maintenance Workers in Australia

    NARCIS (Netherlands)

    Guest, Maya; Attia, John R.; D'Este, Catherine A.; Boggess, May M.; Brown, Anthony M.; Gibson, Richard E.; Tavener, Meredith A.; Ross, James; Gardner, Ian; Harrex, Warren

    2011-01-01

    Objective: This study aimed to examine possible persisting peripheral neuropathy in a group who undertook fuel tank repairs on F-111 aircraft, relative to two contemporaneous comparison groups. Methods: Vibration perception threshold (VPT) was tested using biothesiometry in 614 exposed personnel, co

  8. Effects of vibrating insoles on standing balance in diabetic neuropathy

    NARCIS (Netherlands)

    Hijmans, Juha M.; Geertzen, Jan H. B.; Zijlstra, Wiebren; Hof, At L.; Postema, Klaas

    2008-01-01

    This study investigated the effects on standing balance of random vibrations applied to the plantar side of the feet by vibrating insoles in subjects with neuropathy and nondisabled subjects. In four different conditions (eyes open or closed and with or without an attention-demanding task [ATD]), su

  9. [An Undeniable Case of Optic Neuropathy Due to Cabazitaxel].

    Science.gov (United States)

    Noguchi, Yusuke; Kawashima, Yugo; Kawara, Hiroko; Kaneko, Masatomo; Nakauchi, Hiroo; Tokuyama, Yoko

    2016-06-01

    Cabazitaxelis a taxane-type antineoplastic agent used for treating prostate cancer. Although typical side effects include neutropenia and fatigue, no studies have investigated eye disorders as a possible side effect, and the details are not clear. Herein, we report our experience of an undeniable case of optic neuropathy caused by cabazitaxel. A 78-year-old man had been diagnosed with prostate cancer (cT3aN1M1b, stage IV) 3 years previously, with a treatment history of bicalutamide, leuprorelin, flutamide, docetaxel, abiraterone, and enzalutamide. Because of a decline in vision during the second and third administration cycles of cabazitaxel, the patient visited an ophthalmologist. He was found to have reduced visual acuity, reduced central critical flicker frequency, narrowed field of vision, and impaired color vision, and was diagnosed with optic neuropathy. Although cabazitaxel administration was continued through 6 cycles, the symptoms were unchanged, and no drastic exacerbation was seen. This patient undeniably developed optic neuropathy due to cabazitaxel. Optic neuropathy due to taxane-type antineoplastic agents has also been reported with paclitaxel or docetaxel, and all precautions should be taken when administering such drugs. Detailed studies that include data from a larger number of facilities should be conducted in the future. PMID:27306820

  10. Sight-threatening optic neuropathy is associated with paranasal lymphoma

    Directory of Open Access Journals (Sweden)

    Takahiko Hayashi

    2010-03-01

    Full Text Available Takahiko Hayashi1, Ken Watanabe2, Yukio Tsuura3, Gengo Tsuji4, Shingo Koyama4, Jun Yoshigi4, Naoko Hirata1, Shin Yamane1, Yasuhito Iizima5, Shigeo Toyota6, Satoshi Takeuchi11Department of Ophthalmology, Yokosuka Kyosai Hospital, Japan; 2Department of Hematology, Graduate School of Medicine, Tokyo Medical and Dental University, Japan; 3Department of Pathology, Yokosuka Kyosai Hospital, Japan; 4Department of Radiology, Yokosuka Kyosai Hospital, Japan; 5Department of Ophthalmology, Yokohama City University, Japan; 6Department of Internal Medicine, Yokosuka Kyosai Hospital, JapanAbstract: Malignant lymphoma around the orbit is very rare. We present a rare case of optic neuropathy caused by lymphoma. A 61-year-old Japanese woman was referred to our hospital for evaluation of idiopathic optic neuropathy affecting her right eye. The patient was treated with steroid pulse therapy (methyl-predonisolone 1 g daily for 3 days with a presumed diagnosis of idiopathic optic neuritis. After she had been switched to oral steroid therapy, endoscopic sinus surgery had been performed, which revealed diffuse large B cell lymphoma of the ethmoidal sinus. Although R-CHOP therapy was immediately started, prolonged optic nerve compression resulted in irreversible blindness. Accordingly, patients with suspected idiopathic optic neuritis should be carefully assessed when they show a poor response, and imaging of the orbits and brain should always be done for initial diagnosis because they may have compression by a tumor.Keywords: optic neuropathy, malignant lymphoma, paranasal lymphoma, rhinogenic optic neuropathy

  11. Mixed connective tissue disease presenting as trigeminal neuropathy

    OpenAIRE

    Edmondstone, W M; Price, D. K.; Shepherd, T. H.; Gooddy, W. W.

    1982-01-01

    A 25-year-old man presented with an isolated trigeminal neuropathy 13 months before developing myalgia and lymphadenopathy. The onset of Raynaud's phenomenon 2 months later suggested a diagnosis of mixed connective tissue disease (MCTD) and this was confirmed by high serum titres of speckled pattern antinuclear antibody, and antibody to ribonuclear protein.

  12. On the many faces of Leber hereditary optic neuropathy

    NARCIS (Netherlands)

    Oostra, RJ; Tijmes, NT; Cobben, JM; Bolhuis, PA; vanNesselrooij, BPM; Houtman, WA; deKokNazaruk, MM; BleekerWagemakers, EM

    1997-01-01

    Leber hereditary optic neuropathy (LHON) is a maternally inherited disorder, associated with mutations in the mitochondrial DNA, which is notorious for its aspecific presentations. Two pedigrees are described with cases that are atypical for LHON with respect to sex, age of onset, interval between t

  13. Gene-environment interactions in Leber hereditary optic neuropathy

    NARCIS (Netherlands)

    M.A. Kirkman; P. Yu-Wai-Man (Patrick); A. Korsten (Alex); M. Leonhardt (Miriam); K. Dimitriadis (Konstantin); I.F.M. de Coo (René); T. Klopstock (Thomas); P.F. Chinnery

    2009-01-01

    textabstractLeber hereditary optic neuropathy (LHON) is a genetic disorder primarily due to mutations of mitochondrial DNA (mtDNA). Environmental factors are thought to precipitate the visual failure and explain the marked incomplete penetrance of LHON, but previous small studies have failed to conf

  14. Visual Rehabilitation of Persons with Leber's Hereditary Optic Neuropathy.

    Science.gov (United States)

    Rudanko, S.-L.

    1995-01-01

    This article presents results of a noncontrolled clinical study of 20 persons with Leber's hereditary optic neuropathy who were treated from 1976 to 1990 at the Low Vision Centre of the Finnish Federation of the Visually Handicapped. The importance of early functional visual rehabilitation is emphasized, as is the use of low vision aids to help…

  15. Oxidative stress and diabetic neuropathy : pathophysiotogical mechanisms and treatment perspectives

    NARCIS (Netherlands)

    2002-01-01

    Increased oxidative stress is a mechanism that probably plays a major role in the development of diabetic complications, including peripheral neuropathy. This review summarises recent data from in vitro and in vivo studies that have been performed both to understand this aspect of the pathophysiolog

  16. Recent advances in exploring the genetic susceptibility to diabetic neuropathy.

    Science.gov (United States)

    Politi, Cristina; Ciccacci, Cinzia; D'Amato, Cinzia; Novelli, Giuseppe; Borgiani, Paola; Spallone, Vincenza

    2016-10-01

    Diabetic polyneuropathy and cardiovascular autonomic neuropathy are common and disabling complications of diabetes. Although glycaemic control and cardiovascular risk factors are major contributory elements in its development, diabetic neuropathy recognizes a multifactorial influence and a multiplicity of pathogenetic mechanisms. Thus genetic and environmental factors may contribute to its susceptibility, each with a modest contribution, by targeting various metabolic and microvascular pathways whose alterations intervene in diabetic neuropathy pathogenesis. This review is aimed at describing major data from the available literature regarding genetic susceptibility to diabetic neuropathies. It provides an overview of the genes reported as associated with the development or progression of these complications, i.e. ACE, MTHFR, GST, GLO1, APOE, TCF7L2, VEGF, IL-4, GPX1, eNOS, ADRA2B, GFRA2, MIR146A, MIR128A. The identification of genetic susceptibility can help in both expanding the comprehension of the pathogenetic mechanisms of diabetic nerve damage and identifying biomarkers of risk prediction and response to therapeutic intervention.

  17. Mexiletine for treatment of chronic painful diabetic neuropathy

    DEFF Research Database (Denmark)

    Dejgard, A; Kastrup, J; Petersen, P

    1988-01-01

    Sixteen of nineteen patients completed a randomised double-blind crossover trial to assess the effect of oral mexiletine (10 mg/kg bodyweight daily) on the symptoms and signs of chronic painful diabetic neuropathy. The median age of the sixteen patients was 50 years (range 30-64). Assessment...

  18. Protective effect of Jiaweibugan decoction against diabetic peripheral neuropathy

    Institute of Scientific and Technical Information of China (English)

    Yu Wang; Zeqi Chen; Renqun Ye; Yulei He; Yuhong Li; Xinjian Qiu

    2013-01-01

    Oxygen free radical damage is regarded as a direct or indirect common pathway associated with diabetic neuropathy and is the main cause of complications in peripheral neuropathies. We speculate that Jiaweibugan decoction has a significant effect in treating diabetic peripheral neuropathy through an anti-oxidative stress pathway. In this study, a diabetic rat model was established by intraperitoneal injection of streptozotocin. Rats were treated with Jiaweibugan decoction via intragastric administration. The levels of malondialdehyde and glutathione, which are indirect indexes of oxidative stress, in serum were determined using a colorimetric method. The expression levels of nuclear factor kappa B p65 mRNA and p38 mitogen-activated protein kinase, which are oxidative stress associated factors, in the dorsal root ganglion of spinal S4–6 segments were evaluated by reverse-transcriptase polymerase chain reaction and immunohistochemistry. Results showed that, Jiaweibugan decoction significantly ameliorated motor nerve conduction velocity in diabetic rats, effectively decreased malondialdehyde levels in serum and the expression of nuclear factor kappa B p65 mRNA and p38 mitogen-activated protein kinase mRNA in the dorsal root ganglion, and increased glutathione levels in serum. Therefore, our experimental findings indicate that Jiaweibugan decoction plays an anti-oxidative stress role in the diabetic peripheral neuropathy process, which has a protective effect on peripheral nerve injury.

  19. [Diagnosis of the peripheral hereditary neuropathies and its molecular genetics].

    Science.gov (United States)

    Hernández-Zamora, Edgar; Arenas-Sordo, María de la Luz

    2008-01-01

    Peripheral neuropathies include a wide range of pathological disorders characterized by damage of peripheral nerves. Among them, peripheral hereditary neuropathies are a group of frequent illnesses and early evolution. They have been named hereditary motor and sensory neuropathy (HMSN) or peripheral hereditary neuropathies type Charcot-Marie-Tooth (CMT). The most frequent types are CMT1, CMT2 and CMTX. Approximately 70% of the cases correspond to subtype CMT1A, associated with tandem duplication of a 1.5 Mb DNA fragment on chromosome 17p11.2-p12 that codifies the peripheral myelin protein PMP22. So far, there five different types of CMT (1,2,3,4,X) with approximately 32 subtypes, associated with more than 30 genes. Have been reported genetic heterogeneity and expression variability of the illness makes it necessary to carry on diagnostic strategies that integrate clinical study for determining genetic clinical history, family history, complete physical exploration, muscular strength, physical deformities, reflexes and sensitivity, and molecular studies allow detection of different types of mutations and help establish a correct diagnosis and an adequate genetic counseling.

  20. Burden of Chemotherapy-Induced Neuropathy in School ged children

    Directory of Open Access Journals (Sweden)

    Artan Shkoza

    2015-11-01

    Full Text Available Chemotherapy-induced peripheral neuropathy (CIPN is the most common neurological complication in cancer treatment and probably the most common toxic neuropathy in our environment. The aim of the study was to assess the incidence and discomfort caused by neuropathic symptoms in children treated for hematologic cancers. The study included all children admitted to the pediatric oncology service at the University Hospital Center “Mother Teresa”, Tirana, by the year 2011 – 2013 divided in three diagnosis groups: acute lymphoblastic leukemia, Hodgkin and non-Hodgkin’s lymphoma, or other solid tumors. In a prospective cohort setting, data were collected by standard questionnaire for symptoms and signs of neurological damage, according to The Pediatric - Modified Total Neuropathy Scale (Ped - mTNS, as well as clinical evaluation of pin sensibility, vibration sensibility, muscle strength and deep tendon reflexes (DTR. The results obtained from Ped-mTNS, showed the high incidence of sensory and motor symptoms as well as functional deficits in balance and manual dexterity in children treated with anticancer drugs. Ped-mTNS scores, as the first measure designed to assess CIPN in school-aged children, are significantly higher for children undergoing neurotoxic chemotherapy. Even though the neuropathy in these children was relatively mild, it was associated with functional deficits in balance and manual dexterity, suggesting clinical importance. An important limiting factor of this study is the exclusion of children younger than 5 years old, whom discomfort is evident but not properly evaluated.

  1. Genetics Home Reference: hereditary sensory and autonomic neuropathy type II

    Science.gov (United States)

    ... article on PubMed Central Huang CL, Kuo E. Mechanisms of disease: WNK-ing at the mechanism of salt-sensitive hypertension. Nat Clin Pract Nephrol. ... Verpoorten N, De Jonghe P, Timmerman V. Disease mechanisms in hereditary sensory and autonomic neuropathies. Neurobiol Dis. ...

  2. Brachial plexus neuropathy - A long-term outcome study

    NARCIS (Netherlands)

    Geertzen, JHB; Groothoff, JW; Nicolai, JP; Rietman, JS

    2000-01-01

    This retrospective study assessed the long-term outcome of brachial plexus neuropathy in 16 patients. The mean follow up was 8 years. Nine patients complained of persistent pain and muscle weakness, four had continuing problems with various activities of daily living and 11 had trouble with some hou

  3. Axon diameter and intra-axonal volume fraction of the corticospinal tract in idiopathic normal pressure hydrocephalus measured by q-space imaging.

    Directory of Open Access Journals (Sweden)

    Kouhei Kamiya

    Full Text Available PURPOSE: Previous studies suggest that compression and stretching of the corticospinal tract (CST potentially cause treatable gait disturbance in patients with idiopathic normal pressure hydrocephalus (iNPH. Measurement of axon diameter with diffusion MRI has recently been used to investigate microstructural alterations in neurological diseases. In this study, we investigated alterations in the axon diameter and intra-axonal fraction of the CST in iNPH by q-space imaging (QSI analysis. METHODS: Nineteen patients with iNPH and 10 age-matched controls were recruited. QSI data were obtained with a 3-T system by using a single-shot echo planar imaging sequence with the diffusion gradient applied parallel to the antero-posterior axis. By using a two-component low-q fit model, the root mean square displacements of intra-axonal space ( =  axon diameter and intra-axonal volume fraction of the CST were calculated at the levels of the internal capsule and body of the lateral ventricle, respectively. RESULTS: Wilcoxon's rank-sum test revealed a significant increase in CST intra-axonal volume fraction at the paraventricular level in patients (p<0.001, whereas no significant difference was observed in the axon diameter. At the level of the internal capsule, neither axon diameter nor intra-axonal volume fraction differed significantly between the two groups. CONCLUSION: Our results suggest that in patients with iNPH, the CST does not undergo irreversible axonal damage but is rather compressed and/or stretched owing to pressure from the enlarged ventricle. These analyses of axon diameter and intra-axonal fraction yield insights into microstructural alterations of the CST in iNPH.

  4. Oestrogens ameliorate mitochondrial dysfunction in Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Giordano, Carla; Montopoli, Monica; Perli, Elena; Orlandi, Maurizia; Fantin, Marianna; Ross-Cisneros, Fred N; Caparrotta, Laura; Martinuzzi, Andrea; Ragazzi, Eugenio; Ghelli, Anna; Sadun, Alfredo A; d'Amati, Giulia; Carelli, Valerio

    2011-01-01

    Leber's hereditary optic neuropathy, the most frequent mitochondrial disease due to mitochondrial DNA point mutations in complex I, is characterized by the selective degeneration of retinal ganglion cells, leading to optic atrophy and loss of central vision prevalently in young males. The current study investigated the reasons for the higher prevalence of Leber's hereditary optic neuropathy in males, exploring the potential compensatory effects of oestrogens on mutant cell metabolism. Control and Leber's hereditary optic neuropathy osteosarcoma-derived cybrids (11778/ND4, 3460/ND1 and 14484/ND6) were grown in glucose or glucose-free, galactose-supplemented medium. After having shown the nuclear and mitochondrial localization of oestrogen receptors in cybrids, experiments were carried out by adding 100 nM of 17β-oestradiol. In a set of experiments, cells were pre-incubated with the oestrogen receptor antagonist ICI 182780. Leber's hereditary optic neuropathy cybrids in galactose medium presented overproduction of reactive oxygen species, which led to decrease in mitochondrial membrane potential, increased apoptotic rate, loss of cell viability and hyper-fragmented mitochondrial morphology compared with control cybrids. Treatment with 17β-oestradiol significantly rescued these pathological features and led to the activation of the antioxidant enzyme superoxide dismutase 2. In addition, 17β-oestradiol induced a general activation of mitochondrial biogenesis and a small although significant improvement in energetic competence. All these effects were oestrogen receptor mediated. Finally, we showed that the oestrogen receptor β localizes to the mitochondrial network of human retinal ganglion cells. Our results strongly support a metabolic basis for the unexplained male prevalence in Leber's hereditary optic neuropathy and hold promises for a therapeutic use for oestrogen-like molecules.

  5. Wnt-induced calcium signaling mediates axon growth and guidance in the developing corpus callosum.

    Science.gov (United States)

    Hutchins, B Ian; Li, Li; Kalil, Katherine

    2012-01-10

    Wnt5a gradients guide callosal axons by repulsion through Ryk receptors in vivo. We recently found that Wnt5a repels cortical axons and promotes axon outgrowth through calcium signaling in vitro. Here, using cortical slices, we show that Wnt5a signals through Ryk to guide and promote outgrowth of callosal axons after they cross the midline. Calcium transient frequencies in callosal growth cones positively correlate with axon outgrowth rates in vitro. In cortical slices, calcium release through inositol 1,4,5-trisphosphate (IP(3)) receptors and calcium entry through transient receptor potential channels modulate axon growth and guidance. Knocking down Ryk inhibits calcium signaling in cortical axons, reduces rates of axon outgrowth subsequent to midline crossing, and causes axon guidance defects. Calcium- and calmodulin-dependent protein kinase II (CaMKII) is required downstream of Wnt-induced calcium signaling for postcrossing callosal axon growth and guidance. Taken together, these results suggest that growth and guidance of postcrossing callosal axons by Wnt-Ryk-calcium signaling involves axon repulsion through CaMKII.

  6. Chronic excitotoxin-induced axon degeneration in a compartmented neuronal culture model

    Directory of Open Access Journals (Sweden)

    Katherine A Hosie

    2012-02-01

    Full Text Available Glutamate excitotoxicity is a major pathogenic process implicated in many neurodegenerative conditions, including AD (Alzheimer's disease and following traumatic brain injury. Occurring predominantly from over-stimulation of ionotropic glutamate receptors located along dendrites, excitotoxic axonal degeneration may also occur in white matter tracts. Recent identification of axonal glutamate receptor subunits within axonal nanocomplexes raises the possibility of direct excitotoxic effects on axons. Individual neuronal responses to excitotoxicity are highly dependent on the complement of glutamate receptors expressed by the cell, and the localization of the functional receptors. To enable isolation of distal axons and targeted excitotoxicity, murine cortical neuron cultures were prepared in compartmented microfluidic devices, such that distal axons were isolated from neuronal cell bodies. Within the compartmented culture system, cortical neurons developed to relative maturity at 11 DIV (days in vitro as demonstrated by the formation of dendritic spines and clustering of the presynaptic protein synaptophysin. The isolated distal axons retained growth cone structures in the absence of synaptic targets, and expressed glutamate receptor subunits. Glutamate treatment (100 μM to the cell body chamber resulted in widespread degeneration within this chamber and degeneration of distal axons in the other chamber. Glutamate application to the distal axon chamber triggered a lesser degree of axonal degeneration without degenerative changes in the untreated somal chamber. These data indicate that in addition to current mechanisms of indirect axonal excitotoxicity, the distal axon may be a primary target for excitotoxicity in neurodegenerative conditions.

  7. Differential Axonal Projection of Mitral and Tufted Cells in the Mouse Main Olfactory System

    Directory of Open Access Journals (Sweden)

    Shin Nagayama

    2010-09-01

    Full Text Available In the past decade, much has been elucidated regarding the functional organization of the axonal connection of olfactory sensory neurons to olfactory bulb (OB glomeruli. However, the manner in which projection neurons of the OB process odorant input and send this information to higher brain centers remains unclear. Here, we report long-range, large-scale tracing of the axonal projection patterns of OB neurons using two-photon microscopy. Tracer injection into a single glomerulus demonstrated widely distributed mitral/tufted cell axonal projections on the lateroventral surface of the mouse brain, including the anterior/posterior piriform cortex (PC and olfactory tubercle (OT. We noted two distinct groups of labeled axons: PC-orienting axons and OT-orienting axons. Each group occupied distinct parts of the lateral olfactory tract. PC-orienting axons projected axon collaterals to a wide area of the PC but only a few collaterals to the OT. OT-orienting axons densely projected axon collaterals primarily to the anterolateral OT (alOT. Different colored dye injections into the superficial and deep portions of the OB external plexiform layer revealed that the PC-orienting axon populations originated in presumed mitral cells and the OT-orienting axons in presumed tufted cells. These data suggest that although mitral and tufted cells receive similar odor signals from a shared glomerulus, they process the odor information in different ways and send their output to different higher brain centers via the PC and alOT.

  8. Spectrins in axonal cytoskeletons: Dynamics revealed by extensions and fluctuations

    Science.gov (United States)

    Lai, Lipeng; Cao, Jianshu

    2014-07-01

    The macroscopic properties, the properties of individual components, and how those components interact with each other are three important aspects of a composited structure. An understanding of the interplay between them is essential in the study of complex systems. Using axonal cytoskeleton as an example system, here we perform a theoretical study of slender structures that can be coarse-grained as a simple smooth three-dimensional curve. We first present a generic model for such systems based on the fundamental theorem of curves. We use this generic model to demonstrate the applicability of the well-known worm-like chain (WLC) model to the network level and investigate the situation when the system is stretched by strong forces (weakly bending limit). We specifically studied recent experimental observations that revealed the hitherto unknown periodic cytoskeleton structure of axons and measured the longitudinal fluctuations. Instead of focusing on single molecules, we apply analytical results from the WLC model to both single molecule and network levels and focus on the relations between extensions and fluctuations. We show how this approach introduces constraints to possible local dynamics of the spectrin tetramers in the axonal cytoskeleton and finally suggests simple but self-consistent dynamics of spectrins in which the spectrins in one spatial period of axons fluctuate in-sync.

  9. Drosophila Ryks and their roles in axon and muscle guidance

    NARCIS (Netherlands)

    Lahaye, Liza Lucia

    2015-01-01

    In the last decade it has become clear that a number of the molecular mechanisms that are required for proper navigation of axons in complex nervous systems are also employed to guide muscles to their appropriate attachment sites. Among the gene families that mediate these diverse processes is the R

  10. Traction Force and Tension Fluctuations During Axon Growth

    Directory of Open Access Journals (Sweden)

    Jamison ePolackwich

    2015-10-01

    Full Text Available Actively generated mechanical forces play a central role in axon growthand guidance, but the mechanisms that underly force generation andregulation in growing axons remain poorly understood. We reportmeasurements of the dynamics of traction stresses from growth cones ofactively advancing axons from postnatal rat DRG neurons. By tracking themovement of the growth cone and analyzing the traction stress field froma reference frame that moves with it, we are able to show that there isa clear and consistent average stress field that underlies the complexspatial stresses present at any one time. The average stress field hasstrong maxima on the sides of the growth cone, directed inward towardthe growth cone neck. This pattern represents a contractile stresscontained within the growth cone, and a net force that is balanced bythe axon tension. Using high time-resolution measurements of the growthcone traction stresses, we show that the stress field is composed offluctuating local stress peaks, with a large number peaks that live fora short time, a population of peaks whose lifetime distribution followsan exponential decay, and a small number of very long-lived peaks. Weshow that the high time-resolution data also reveal that the tensionappears to vary randomly over short time scales, roughly consistent withthe lifetime of the stress peaks, suggesting that the tensionfluctuations originate from stochastic adhesion dynamics.

  11. Life-or-death decisions upon axonal damage.

    Science.gov (United States)

    Roselli, Francesco; Caroni, Pico

    2012-02-01

    In this issue of Neuron, Hu et al. (2012) report that upon axonal damage, CHOP and XBP1 unfolded protein response pathways are not recruited equally and have opposite effects on neuronal survival. XBP1 pathway boosting may represent a valuable neuroprotective strategy.

  12. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

    Jensen, M B; Hegelund, I V; Lomholt, N D;

    2000-01-01

    periods. Message for the immune cytokine interferon-gamma (IFNgamma) was undetectable, and glial reactivity to axonal lesions occurred as normal in IFNgamma-deficient mice. Microglial responses to lesion-induced neuronal injury were markedly enhanced in myelin basic protein promoter-driven transgenic mice...

  13. PTEN inhibition and axon regeneration and neural repair

    Institute of Scientific and Technical Information of China (English)

    Yosuke Ohtake; Umar Hayat; Shuxin Li

    2015-01-01

    The intrinsic growth ability of all the neurons declines during development although some may grow better than others. Numerous intracellular signaling proteins and transcription factors have been shown to regulate the intrinsic growth capacity in mature neurons. Among them, PI3 kinase/Akt pathway is important for controlling axon elongation. As a negative regulator of this pathway, the tumor suppressor phosphatase and tensin homolog (PTEN) appears critical to con-trol the regenerative ability of young and adult neurons. This review will focus on recent research progress in axon regeneration and neural repair by PTEN inhibition and therapeutic potential of blocking this phosphatase for neurological disorders. Inhibition of PTEN by deletion in con-ditional knockout mice, knockdown by short-hairpin RNA, or blockade by pharmacological approaches, including administration of selective PTEN antagonist peptides, stimulates various degrees of axon regrowth in juvenile or adult rodents with central nervous system injuries. Im-portantly, post-injury PTEN suppression could enhance axonal growth and functional recovery in adult central nervous system after injury.

  14. Quantifying mechanical force in axonal growth and guidance

    Directory of Open Access Journals (Sweden)

    Ahmad Ibrahim Mahmoud Athamneh

    2015-09-01

    Full Text Available Mechanical force plays a fundamental role in neuronal development, physiology, and regeneration. In particular, research has shown that force is involved in growth cone-mediated axonal growth and guidance as well as stretch-induced elongation when an organism increases in size after forming initial synaptic connections. However, much of the details about the exact role of force in these fundamental processes remain unknown. In this review, we highlight (1 standing questions concerning the role of mechanical force in axonal growth and guidance and (2 different experimental techniques used to quantify forces in axons and growth cones. We believe that satisfying answers to these questions will require quantitative information about the relationship between elongation, forces, cytoskeletal dynamics, axonal transport, signaling, substrate adhesion, and stiffness contributing to directional growth advance. Furthermore, we address why a wide range of force values have been reported in the literature, and what these values mean in the context of neuronal mechanics. We hope that this review will provide a guide for those interested in studying the role of force in development and regeneration of neuronal networks.

  15. Axonal regeneration and development of de novo axons from distal dendrites of adult feline commissural interneurons after a proximal axotomy

    DEFF Research Database (Denmark)

    Fenrich, Keith K; Skelton, Nicole; MacDermid, Victoria E;

    2007-01-01

    the soma or a very proximal dendrite. L-ALPs were devoid of MAP2a/b immunoreactivity. Some of these L-ALPs projected through the lesion and formed bouton-like swellings. These results suggest that proximally axotomized spinal interneurons have the potential to form new connections via de novo axons...

  16. White matter involvement after TBI: Clues to axon and myelin repair capacity.

    Science.gov (United States)

    Armstrong, Regina C; Mierzwa, Amanda J; Marion, Christina M; Sullivan, Genevieve M

    2016-01-01

    Impact-acceleration forces to the head cause traumatic brain injury (TBI) with damage in white matter tracts comprised of long axons traversing the brain. White matter injury after TBI involves both traumatic axonal injury (TAI) and myelin pathology that evolves throughout the post-injury time course. The axon response to initial mechanical forces and secondary insults follows the process of Wallerian degeneration, which initiates as a potentially reversible phase of intra-axonal damage and proceeds to an irreversible phase of axon fragmentation. Distal to sites of axon disconnection, myelin sheaths remain for prolonged periods, which may activate neuroinflammation and inhibit axon regeneration. In addition to TAI, TBI can cause demyelination of intact axons. These evolving features of axon and myelin pathology also represent opportunities for repair. In experimental TBI, demyelinated axons exhibit remyelination, which can serve to both protect axons and facilitate recovery of function. Myelin remodeling may also contribute to neuroplasticity. Efficient clearance of myelin debris is a potential target to attenuate the progression of chronic pathology. During the early phase of Wallerian degeneration, interventions that prevent the transition from reversible damage to axon disconnection warrant the highest priority, based on the poor regenerative capacity of axons in the CNS. Clinical evaluation of TBI will need to address the challenge of accurately detecting the extent and stage of axon damage. Distinguishing the complex white matter changes associated with axons and myelin is necessary for interpreting advanced neuroimaging approaches and for identifying a broader range of therapeutic opportunities to improve outcome after TBI. PMID:25697845

  17. IH activity is increased in populations of slow versus fast motor axons of the rat.

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    Chad eLorenz

    2014-09-01

    Full Text Available Much is known about the electrophysiological variation in motoneuron somata across different motor units. However comparatively less is known about electrophysiological variation in motor axons and how this could impact function or electrodiagnosis in healthy or diseased states. We performed nerve excitability testing on two groups of motor axons in Sprague-Dawley rats that are known to differ significantly in their chronic daily activity patterns and in the relative proportion of motor unit types: one group innervating the soleus (slow motor axons and the other group innervating the tibialis anterior (fast motor axons muscles. We found that slow motor axons have significantly larger accommodation compared to fast motor axons upon application of a 100 ms hyperpolarizing conditioning stimulus that is 40% of axon threshold (Z = 3.24, p = 0.001 or 20% of axon threshold (Z = 2.67, p = 0.008. Slow motor axons had larger accommodation to hyperpolarizing currents in the current-threshold measurement (-80% Z = 3.07, p = 0.002; -90% Z = 2.98, p = 0.003. In addition, we found that slow motor axons have a significantly smaller rheobase than fast motor axons (Z = -1.99, p = 0.047 accompanied by a lower threshold in stimulus-response curves. The results provide evidence that slow motor axons have greater activity of the hyperpolarization-activated inwardly rectifying cation conductance (IH than fast motor axons. It is possible that this difference between fast and slow axons is caused by an adaptation to their chronic differences in daily activity patterns, and that this adaptation might have a functional effect on the motor unit. Moreover, these findings indicate that slow and fast motor axons may react differently to pathological conditions.

  18. 四例化学物中毒性周围神经病患者病理特点及神经电生理分析%Pathology and neurophysiology analysis for peripheral neuropathy of four patients with chemicals poisoning

    Institute of Scientific and Technical Information of China (English)

    张静波; 张巧耘; 王勇; 孙道远

    2012-01-01

    Objective To study the nerve electromyogram results by analysing the pathological characters of 4 cases diagnosed as peripheral neuropathy caused by n-hexane and arsenic.Methods The nerve electromyogram examination and pathology data of 4 patients,who had been diagnosed as toxic chemicals peripheral neuropathy,were studied retrospectively.Results Two patients in this group were exposed to nhexane,their nerve electromyogram examinations and biopsy pathology of superficial peroneal nerve indicated the peripheral neuropathy was mainly manifests the lesion of medullary sheath.Another two patients were exposed to arsenic,their nerve electromyogram examinations showed axonal degeneration associated with demyelination,and their biopsy pathology showed the peripheral neuropathy was mainly axonal degeneration.Conclusion Axonal degeneration and demyelination always coexist in peripheral neuropathy caused by chemicals.%目的 通过对4例化学物中毒性周围神经病变的病理特点分析,诠释慢性正己烷、砷中毒时的神经电生理结果.方法 回顾4例化学物中毒性周围神经病患者,分析其神经电生理及周围神经病理特点.结果 4例患者中2例为慢性轻度正己烷中毒,神经电生理检查提示髓鞘脱失和轴索损害均存在,腓浅神经活检病理示以髓鞘损害为主的周围神经病变;另2例为亚急性砷中毒患者,神经电生理检查提示轴索损害伴髓鞘脱失,病理活检示轻度周围神经损害,以轴索为主.结论 化学物中毒性周围神经病的病理改变随着病程进展可同时存在轴索病变和脱髓鞘改变.

  19. FMRP-Mediated Axonal Delivery of miR-181d Regulates Axon Elongation by Locally Targeting Map1b and Calm1

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    Bin Wang

    2015-12-01

    Full Text Available Subcellular targeting and local translation of mRNAs are critical for axon development. However, the precise local control of mRNA translation requires investigation. We report that the Fmr1-encoded protein, FMRP-mediated axonal delivery of miR-181d negatively regulates axon elongation by locally targeting the transcripts of MAP1B (Map1b and calmodulin (Calm1 in primary sensory neurons. miR-181d affected the local synthesis of MAP1B and calmodulin in axons. FMRP was associated with miR-181d, Map1b, and Calm1. Both FMRP deficiency in Fmr1I304N mice and Fmr1 knockdown impeded the axonal delivery of miR-181d, Map1b, and Calm1 and reduced the protein levels of MAP1B and calmodulin in axons. Furthermore, nerve growth factor (NGF induced Map1b and Calm1 release from FMRP and miR-181d-repressing granules, thereby promoting axon elongation. Both miR-181d overexpression and FMRP knockdown impaired NGF-induced axon elongation. Our study reveals a mechanism for the local regulation of translation by miR-181d and FMRP during axon development.

  20. Alterations of mitochondrial dynamics allow retrograde propagation of locally initiated axonal insults.

    Science.gov (United States)

    Lassus, Benjamin; Magifico, Sebastien; Pignon, Sandra; Belenguer, Pascale; Miquel, Marie-Christine; Peyrin, Jean-Michel

    2016-01-01

    In chronic neurodegenerative syndromes, neurons progressively die through a generalized retraction pattern triggering retrograde axonal degeneration toward the cell bodies, which molecular mechanisms remain elusive. Recent observations suggest that direct activation of pro-apoptotic signaling in axons triggers local degenerative events associated with early alteration of axonal mitochondrial dynamics. This raises the question of the role of mitochondrial dynamics on both axonal vulnerability stress and their implication in the spreading of damages toward unchallenged parts of the neuron. Here, using microfluidic chambers, we assessed the consequences of interfering with OPA1 and DRP1 proteins on axonal degeneration induced by local application of rotenone. We found that pharmacological inhibition of mitochondrial fission prevented axonal damage induced by rotenone, in low glucose conditions. While alteration of mitochondrial dynamics per se did not lead to spontaneous axonal degeneration, it dramatically enhanced axonal vulnerability to rotenone, which had no effect in normal glucose conditions, and promoted retrograde spreading of axonal degeneration toward the cell body. Altogether, our results suggest a mitochondrial priming effect in axons as a key process of axonal degeneration. In the context of neurodegenerative diseases, like Parkinson's and Alzheimer's, mitochondria fragmentation could hasten neuronal death and initiate spatial dispersion of locally induced degenerative events. PMID:27604820

  1. Changes in microtubule stability and density in myelin-deficient shiverer mouse CNS axons

    Science.gov (United States)

    Kirkpatrick, L. L.; Witt, A. S.; Payne, H. R.; Shine, H. D.; Brady, S. T.

    2001-01-01

    Altered axon-Schwann cell interactions in PNS myelin-deficient Trembler mice result in changed axonal transport rates, neurofilament and microtubule-associated protein phosphorylation, neurofilament density, and microtubule stability. To determine whether PNS and CNS myelination have equivalent effects on axons, neurofilaments, and microtubules in CNS, myelin-deficient shiverer axons were examined. The genetic defect in shiverer is a deletion in the myelin basic protein (MBP) gene, an essential component of CNS myelin. As a result, shiverer mice have little or no compact CNS myelin. Slow axonal transport rates in shiverer CNS axons were significantly increased, in contrast to the slowing in demyelinated PNS nerves. Even more striking were substantial changes in the composition and properties of microtubules in shiverer CNS axons. The density of axonal microtubules is increased, reflecting increased expression of tubulin in shiverer, and the stability of microtubules is drastically reduced in shiverer axons. Shiverer transgenic mice with two copies of a wild-type myelin basic protein transgene have an intermediate level of compact myelin, making it possible to determine whether the actual level of compact myelin is an important regulator of axonal microtubules. Both increased microtubule density and reduced microtubule stability were still observed in transgenic mouse nerves, indicating that signals beyond synaptogenesis and the mere presence of compact myelin are required for normal regulation of the axonal microtubule cytoskeleton.

  2. Regulation of neuronal axon specification by glia-neuron gap junctions in C. elegans

    Science.gov (United States)

    Meng, Lingfeng; Zhang, Albert; Jin, Yishi; Yan, Dong

    2016-01-01

    Axon specification is a critical step in neuronal development, and the function of glial cells in this process is not fully understood. Here, we show that C. elegans GLR glial cells regulate axon specification of their nearby GABAergic RME neurons through GLR-RME gap junctions. Disruption of GLR-RME gap junctions causes misaccumulation of axonal markers in non-axonal neurites of RME neurons and converts microtubules in those neurites to form an axon-like assembly. We further uncover that GLR-RME gap junctions regulate RME axon specification through activation of the CDK-5 pathway in a calcium-dependent manner, involving a calpain clp-4. Therefore, our study reveals the function of glia-neuron gap junctions in neuronal axon specification and shows that calcium originated from glial cells can regulate neuronal intracellular pathways through gap junctions. DOI: http://dx.doi.org/10.7554/eLife.19510.001 PMID:27767956

  3. Interplay between kinesin-1 and cortical dynein during axonal outgrowth and microtubule organization in Drosophila neurons.

    Science.gov (United States)

    del Castillo, Urko; Winding, Michael; Lu, Wen; Gelfand, Vladimir I

    2015-12-28

    In this study, we investigated how microtubule motors organize microtubules in Drosophila neurons. We showed that, during the initial stages of axon outgrowth, microtubules display mixed polarity and minus-end-out microtubules push the tip of the axon, consistent with kinesin-1 driving outgrowth by sliding antiparallel microtubules. At later stages, the microtubule orientation in the axon switches from mixed to uniform polarity with plus-end-out. Dynein knockdown prevents this rearrangement and results in microtubules of mixed orientation in axons and accumulation of microtubule minus-ends at axon tips. Microtubule reorganization requires recruitment of dynein to the actin cortex, as actin depolymerization phenocopies dynein depletion, and direct recruitment of dynein to the membrane bypasses the actin requirement. Our results show that cortical dynein slides 'minus-end-out' microtubules from the axon, generating uniform microtubule arrays. We speculate that differences in microtubule orientation between axons and dendrites could be dictated by differential activity of cortical dynein.

  4. Plasma adrenaline kinetics in type 1 (insulin-dependent) diabetic patients with and without autonomic neuropathy

    DEFF Research Database (Denmark)

    Dejgaard, A; Hilsted, J; Henriksen, Jens Henrik Sahl;

    1989-01-01

    labelled adrenaline had been stopped was significantly prolonged in Type 1 diabetic patients with neuropathy compared to those without (after 20 min infusion 2.7 vs 2.2 min, p less than 0.02, after 75 min infusion 3.7 vs 2.9 min, p less than 0.05). The corresponding values for the mean sojourn time...... volume in Type 1 diabetic patients with neuropathy as compared to patients without neuropathy (estimated space of distribution 29 vs 20 l). Our results suggest that patients with diabetic neuropathy do not adjust the plasma adrenaline concentration to changes in adrenaline infusion rate as rapidly...... as those without neuropathy, i.e. the effect of an elevated adrenaline secretion rate may be prolonged in patients with diabetic autonomic neuropathy....

  5. The effects of capillary dysfunction on oxygen and glucose extraction in diabetic neuropathy

    DEFF Research Database (Denmark)

    Østergaard, Leif; Finnerup, Nanna B.; Terkelsen, Astrid J.;

    2015-01-01

    Diabetic neuropathy is associated with disturbances in endoneurial metabolism and microvascular morphology, but the roles of these factors in the aetiopathogenesis of diabetic neuropathy remain unclear. Changes in endoneurial capillary morphology and vascular reactivity apparently predate...... the development of diabetic neuropathy in humans, and in manifest neuropathy, reductions in nerve conduction velocity correlate with the level of endoneurial hypoxia. The idea that microvascular changes cause diabetic neuropathy is contradicted, however, by reports of elevated endoneurial blood flow in early...... experimental diabetes, and of unaffected blood flow when early histological signs of neuropathy first develop in humans. We recently showed that disturbances in capillary flow patterns, so-called capillary dysfunction, can reduce the amount of oxygen and glucose that can be extracted by the tissue for a given...

  6. Posterior Ischemic Optic Neuropathy Following Percutaneous Nephrolithotomy

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    Mohammad Pakravan

    2008-12-01

    Full Text Available

    PURPOSE: To report a case of posterior ischemic optic neuropathy (PION following percutaneous nephrolithotomy (PCNL. CASE REPORT: A 57-year-old man with history of diabetes mellitus, hyperlipidemia and mild anemia underwent PCNL for treatment of nephrolithiasis. He noticed painless visual loss in both eyes immediately after the procedure. Visual acuity was light perception, however ophthalmologic examinations were unremarkable and the optic discs were pink with no swelling. Visual fields were severely affected, but neuro-imaging was normal. Within three months, visual acuity and visual fields improved dramatically but the optic discs became slightly pale. CONCLUSION: This is the first report of PION following PCNL. PION is a rare cause of severe visual loss following surgery. Severe blood loss, hypotension, anemia and body position during surgery are the most important risk factors. Ophthalmologists, urologists and anesthesiologists should be aware of this condition and this rare possibility should be considered prior to surgery.