High frequency oscillations evoked by peripheral magnetic stimulation.

Science.gov (United States)

Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

2011-01-01

The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

State-of-the-Art Techniques in Treating Peripheral Nerve Injury.

Science.gov (United States)

Kubiak, Carrie A; Kung, Theodore A; Brown, David L; Cederna, Paul S; Kemp, Stephen W P

2018-03-01

Peripheral nerve injuries remain a major clinical concern, as they often lead to chronic disability and significant health care expenditures. Despite advancements in microsurgical techniques to enhance nerve repair, biological approaches are needed to augment nerve regeneration and improve functional outcomes after injury. Presented herein is a review of the current literature on state-of-the-art techniques to enhance functional recovery for patients with nerve injury. Four categories are considered: (1) electroceuticals, (2) nerve guidance conduits, (3) fat grafting, and (4) optogenetics. Significant study results are highlighted, focusing on histologic and functional outcome measures. This review documents the current state of the literature. Advancements in neuronal stimulation, tissue engineering, and cell-based therapies demonstrate promise with regard to augmenting nerve regeneration and appropriate rehabilitation. The future of treating peripheral nerve injury will include multimodality use of electroconductive conduits, fat grafting, neuronal stimulation, and optogenetics. Further clinical investigation is needed to confirm the efficacy of these technologies on peripheral nerve recovery in humans, and how best to implement this treatment for a diverse population of nerve-injured patients.

Delayed peripheral nerve repair: methods, including surgical 'cross-bridging' to promote nerve regeneration.

Science.gov (United States)

Gordon, Tessa; Eva, Placheta; Borschel, Gregory H

2015-10-01

Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges) into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to 'protect' chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries.

The successful use of peripheral nerve blocks for femoral amputation

DEFF Research Database (Denmark)

Bech, Birgitte Louise; Melchiors, J; Børglum, J

2009-01-01

We present a case report of four patients with severe cardiac insufficiency where peripheral nerve blocks guided by either nerve stimulation or ultrasonography were the sole anaesthetic for above-knee amputation. The patients were breathing spontaneously and remained haemodynamically stable during...... surgery. Thus, use of peripheral nerve blocks for femoral amputation in high-risk patients seems to be the technique of choice that can lower perioperative risk....

Delayed peripheral nerve repair: methods, including surgical ′cross-bridging′ to promote nerve regeneration

Directory of Open Access Journals (Sweden)

Tessa Gordon

2015-01-01

Full Text Available Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour period of 20 Hz electrical nerve stimulation via electrodes proximal to an injury site accelerates axon outgrowth to hasten target reinnervation in rats and humans, even after delayed surgery. A novel strategy of enticing donor axons from an otherwise intact nerve to grow through small nerve grafts (cross-bridges into a denervated nerve stump, promotes improved axon regeneration after delayed nerve repair. The efficacy of this technique has been demonstrated in a rat model and is now in clinical use in patients undergoing cross-face nerve grafting for facial paralysis. In conclusion, brief electrical stimulation, combined with the surgical technique of promoting the regeneration of some donor axons to ′protect′ chronically denervated Schwann cells, improves nerve regeneration and, in turn, functional outcomes in the management of peripheral nerve injuries.

Electrical muscle stimulation elevates intramuscular BDNF and GDNF mRNA following peripheral nerve injury and repair in rats.

Science.gov (United States)

Willand, Michael P; Rosa, Elyse; Michalski, Bernadeta; Zhang, Jennifer J; Gordon, Tessa; Fahnestock, Margaret; Borschel, Gregory H

2016-10-15

Despite advances in surgery, patients with nerve injuries frequently have functional deficits. We previously demonstrated in a rat model that daily electrical muscle stimulation (EMS) following peripheral nerve injury and repair enhances reinnervation, detectable as early as two weeks post-injury. In this study, we explain the enhanced early reinnervation observed with electrical stimulation. In two groups of rats, the tibial nerve was transected and immediately repaired. Gastrocnemius muscles were implanted with intramuscular electrodes for sham or muscle stimulation. Muscles were stimulated daily, eliciting 600 contractions for one hour/day, repeated five days per week. Sixteen days following nerve injury, muscles were assessed for functional reinnervation by motor unit number estimation methods using electromyographic recording. In a separate cohort of rats, surgical and electrical stimulation procedures were identical but muscles and distal nerve stumps were harvested for molecular analysis. We observed that stimulated muscles had significantly higher motor unit number counts. Intramuscular levels of brain-derived and glial cell line-derived neurotrophic factor (BDNF and GDNF) mRNA were significantly upregulated in muscles that underwent daily electrical stimulation compared to those without stimulation. The corresponding levels of trophic factor mRNA within the distal stump were not different from one another, indicating that the intramuscular electrical stimulus does not modulate Schwann cell-derived trophic factor transcription. Stimulation over a three-month period maintained elevated muscle-derived GDNF but not BDNF mRNA. In conclusion, EMS elevates intramuscular trophic factor mRNA levels which may explain how EMS enhances neural regeneration following nerve injury. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Changes of medium-latency SEP-components following peripheral nerve lesion

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Straschill Max

2006-10-01

Full Text Available Abstract Background Animal studies have demonstrated complex cortical reorganization following peripheral nerve lesion. Central projection fields of intact nerves supplying skin areas which border denervated skin, extended into the deafferentiated cortical representation area. As a consequence of nerve lesions and subsequent reorganization an increase of the somatosensory evoked potentials (SEPs was observed in cats when intact neighbouring nerves were stimulated. An increase of SEP-components of patients with nerve lesions may indicate a similar process of posttraumatic plastic cortical reorganization. Methods To test if a similar process of post-traumatic plastic cortical reorganization does occur in humans, the SEP of intact neighbouring hand nerves were recorded in 29 patients with hand nerve lesions. To hypothetically explain the observed changes of SEP-components, SEP recording following paired stimulation of the median nerve was performed in 12 healthy subjects. Results Surprisingly 16 of the 29 patients (55.2% showed a reduction or elimination of N35, P45 and N60. Patients with lesions of two nerves showed more SEP-changes than patients with a single nerve lesion (85.7%; 6/7 nerves; vs. 34.2%; 13/38 nerves; Fisher's exact test, p Conclusion The results of the present investigation do not provide evidence of collateral innervation of peripherally denervated cortical neurons by neurons of adjacent cortical representation areas. They rather suggest that secondary components of the excitatory response to nerve stimulation are lost in cortical areas, which surround the denervated region.

Raman spectroscopic detection of peripheral nerves towards nerve-sparing surgery

Science.gov (United States)

Minamikawa, Takeo; Harada, Yoshinori; Takamatsu, Tetsuro

2017-02-01

The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery, namely nerve-sparing surgery, is now promising technique to avoid functional deficits of the limbs and organs following surgery as an aspect of the improvement of quality of life of patients. Detection of peripheral nerves including myelinated and unmyelinated nerves is required for the nerve-sparing surgery; however, conventional nerve identification scheme is sometimes difficult to identify peripheral nerves due to similarity of shape and color to non-nerve tissues or its limited application to only motor peripheral nerves. To overcome these issues, we proposed a label-free detection technique of peripheral nerves by means of Raman spectroscopy. We found several fingerprints of peripheral myelinated and unmyelinated nerves by employing a modified principal component analysis of typical spectra including myelinated nerve, unmyelinated nerve, and adjacent tissues. We finally realized the sensitivity of 94.2% and the selectivity of 92.0% for peripheral nerves including myelinated and unmyelinated nerves against adjacent tissues. Although further development of an intraoperative Raman spectroscopy system is required for clinical use, our proposed approach will serve as a unique and powerful tool for peripheral nerve detection for nerve-sparing surgery in the future.

Use of early tactile stimulation in rehabilitation of digital nerve injuries.

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Cheng, A S

2000-01-01

Digital nerves are the most frequently injured peripheral nerve. To improve the recovery of functional sensibility of digital nerve injuries, a prospective randomized controlled study was conducted to see the effect of using early tactile stimulation in rehabilitation of digital nerve injuries. Two specific tactile stimulators were made and prescribed for patients with digital nerve-injury. Twenty-four participants with 32 digital nerve injuries received the prescribed tactile stimulators (experimental group), and another 25 participants with 33 digital nerve injuries received only routine conventional therapy (control group). A significant difference (p sensibility in digital nerve injuries without combined nerve, tendon, and bone injuries.

Nerve conduction and excitability studies in peripheral nerve disorders

DEFF Research Database (Denmark)

Krarup, Christian; Moldovan, Mihai

2009-01-01

counterparts in the peripheral nervous system, in some instances without peripheral nervous system symptoms. Both hereditary and acquired demyelinating neuropathies have been studied and the effects on nerve pathophysiology have been compared with degeneration and regeneration of axons. SUMMARY: Excitability......PURPOSE OF REVIEW: The review is aimed at providing information about the role of nerve excitability studies in peripheral nerve disorders. It has been known for many years that the insight into peripheral nerve pathophysiology provided by conventional nerve conduction studies is limited. Nerve...... excitability studies are relatively novel but are acquiring an increasingly important role in the study of peripheral nerves. RECENT FINDINGS: By measuring responses in nerve that are related to nodal function (strength-duration time constant, rheobase and recovery cycle) and internodal function (threshold...

Silicone Molding and Lifetime Testing of Peripheral Nerve Interfaces for Neuroprostheses

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Gupte, Kimaya [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Biomedical Engineering; Tolosa, Vanessa [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Micro- and Nanotechnology

2016-08-10

Implantable peripheral nerve cuffs have a large application in neuroprostheses as they can be used to restore sensation to those with upper limb amputations. Modern day prosthetics, while lessening the pain associated with phantom limb syndrome, have limited fine motor control and do not provide sensory feedback to patients. Sensory feedback with prosthetics requires communication between the nervous system and limbs, and is still a challenge to accomplish with amputees. Establishing this communication between the peripheral nerves in the arm and artificial limbs is vital as prosthetics research aims to provide sensory feedback to amputees. Peripheral nerve cuffs restore sensation by electrically stimulating certain parts of the nerve in order to create feeling in the hand. Cuff electrodes have an advantage over standard electrodes as they have high selective stimulation by bringing the electrical interface close to the neural tissue in order to selectively activate targeted regions of a peripheral nerve. In order to further improve the selective stimulation of these nerve cuffs, there is need for finer spatial resolution among electrodes. One method to achieve a higher spatial resolution is to increase the electrode density on the cuff itself. Microfabrication techniques can be used to achieve this higher electrode density. Using L-Edit, a layout editor, microfabricated peripheral nerve cuffs were designed with a higher electrode density than the current model. This increase in electrode density translates to an increase in spatial resolution by at least one order of magnitude. Microfabricated devices also have two separate components that are necessary to understand before implantation: lifetime of the device and assembly to prevent nerve damage. Silicone molding procedures were optimized so that devices do not damage nerves in vivo, and lifetime testing was performed on test microfabricated devices to determine their lifetime in vivo. Future work of this project

Selectivity and Longevity of Peripheral-Nerve and Machine Interfaces: A Review

Directory of Open Access Journals (Sweden)

Usman Ghafoor

2017-10-01

Full Text Available For those individuals with upper-extremity amputation, a daily normal living activity is no longer possible or it requires additional effort and time. With the aim of restoring their sensory and motor functions, theoretical and technological investigations have been carried out in the field of neuroprosthetic systems. For transmission of sensory feedback, several interfacing modalities including indirect (non-invasive, direct-to-peripheral-nerve (invasive, and cortical stimulation have been applied. Peripheral nerve interfaces demonstrate an edge over the cortical interfaces due to the sensitivity in attaining cortical brain signals. The peripheral nerve interfaces are highly dependent on interface designs and are required to be biocompatible with the nerves to achieve prolonged stability and longevity. Another criterion is the selection of nerves that allows minimal invasiveness and damages as well as high selectivity for a large number of nerve fascicles. In this paper, we review the nerve-machine interface modalities noted above with more focus on peripheral nerve interfaces, which are responsible for provision of sensory feedback. The invasive interfaces for recording and stimulation of electro-neurographic signals include intra-fascicular, regenerative-type interfaces that provide multiple contact channels to a group of axons inside the nerve and the extra-neural-cuff-type interfaces that enable interaction with many axons around the periphery of the nerve. Section Current Prosthetic Technology summarizes the advancements made to date in the field of neuroprosthetics toward the achievement of a bidirectional nerve-machine interface with more focus on sensory feedback. In the Discussion section, the authors propose a hybrid interface technique for achieving better selectivity and long-term stability using the available nerve interfacing techniques.

Selectivity and Longevity of Peripheral-Nerve and Machine Interfaces: A Review

Science.gov (United States)

Ghafoor, Usman; Kim, Sohee; Hong, Keum-Shik

2017-01-01

For those individuals with upper-extremity amputation, a daily normal living activity is no longer possible or it requires additional effort and time. With the aim of restoring their sensory and motor functions, theoretical and technological investigations have been carried out in the field of neuroprosthetic systems. For transmission of sensory feedback, several interfacing modalities including indirect (non-invasive), direct-to-peripheral-nerve (invasive), and cortical stimulation have been applied. Peripheral nerve interfaces demonstrate an edge over the cortical interfaces due to the sensitivity in attaining cortical brain signals. The peripheral nerve interfaces are highly dependent on interface designs and are required to be biocompatible with the nerves to achieve prolonged stability and longevity. Another criterion is the selection of nerves that allows minimal invasiveness and damages as well as high selectivity for a large number of nerve fascicles. In this paper, we review the nerve-machine interface modalities noted above with more focus on peripheral nerve interfaces, which are responsible for provision of sensory feedback. The invasive interfaces for recording and stimulation of electro-neurographic signals include intra-fascicular, regenerative-type interfaces that provide multiple contact channels to a group of axons inside the nerve and the extra-neural-cuff-type interfaces that enable interaction with many axons around the periphery of the nerve. Section Current Prosthetic Technology summarizes the advancements made to date in the field of neuroprosthetics toward the achievement of a bidirectional nerve-machine interface with more focus on sensory feedback. In the Discussion section, the authors propose a hybrid interface technique for achieving better selectivity and long-term stability using the available nerve interfacing techniques. PMID:29163122

Transverse tripolar stimulation of peripheral nerve: a modelling study of spatial selectivity

NARCIS (Netherlands)

Deurloo, K.E.I.; Holsheimer, J.; Boom, H.B.K.

1998-01-01

Various anode-cathode configurations in a nerve cuff are modelled to predict their spatial selectivity characteristics for functional nerve stimulation. A 3D volume conductor model of a monofascicular nerve is used for the computation of stimulation-induced field potentials, whereas a cable model of

The Effects of Electrocautery on Peripheral Nerve: An Experimental Study.

Science.gov (United States)

Karalezli, Nazim; Koktekir, Ender; Yildirim, Serhat; Toy, Hatice; Oz, Mehmet; Yuceturk, Aydin

2016-05-01

BACKGROUND The aim of this study was to assess the usability of an electrocautery device as nerve stimulator and to investigate histopathologically the adverse effects of electrocautery at low power on rat sciatic nerves. METHODS A total of 36 female Sprague-Dawley albino rats were divided into six groups according to the power applied to their sciatic nerves (1, 2, 3, 4, 5 and 6 W, respectively). Pathologic changes were studied by microscopic examination and scored (no change = 0, mild = 1, moderate = 2, severe = 3). Multiple comparisons were provided for all groups by the Bonferroni test (one-way analysis of variance). A p value  0.05) Variable motor responses and foot deformities were observed at the different power levels. CONCLUSION Although electrocautery devices provoke motor responses if getting in contact with peripheral nerves as do nerve stimulators, their use induces histopathologically adverse effects even at the lowest power. Their use around peripheral nerves should be avoided. Georg Thieme Verlag KG Stuttgart · New York.

Efficacy of ultrasound and nerve stimulation guidance in peripheral nerve block: A systematic review and meta-analysis.

Science.gov (United States)

Wang, Zhi-Xue; Zhang, De-Li; Liu, Xin-Wei; Li, Yan; Zhang, Xiao-Xia; Li, Ru-Hong

2017-09-01

Evidence was controversial about whether nerve stimulation (NS) can optimize ultrasound guidance (US)-guided nerve blockade for peripheral nerve block. This review aims to explore the effects of the two combined techniques. We searched EMBASE (from 1974 to March 2015), PubMed (from 1966 to Mar 2015), Medline (from 1966 to Mar 2015), the Cochrane Central Register of Controlled Trials and clinicaltrials.gov. Finally, 15 randomized trials were included into analysis involving 1,019 lower limb and 696 upper limb surgery cases. Meta-analysis indicated that, compared with US alone, USNS combination had favorable effects on overall block success rate (risk ratio [RR] 1.17; confidence interval [CI] 1.05 to 1.30, P = 0.004), sensory block success rate (RR 1.56; CI 1.29 to 1.89, P block onset time (mean difference [MD] -3.84; CI -5.59 to -2.08, P block (MD 1.67; CI 1.32 to 2.02, P block onset time than US alone as well as higher block success rate, but no statistical difference was demonstrated, as more data are required. © 2017 IUBMB Life, 69(9):720-734, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Peripheral nerve recruitment curve using near-infrared stimulation

Science.gov (United States)

Dautrebande, Marie; Doguet, Pascal; Gorza, Simon-Pierre; Delbeke, Jean; Nonclercq, Antoine

2018-02-01

In the context of near-infrared neurostimulation, we report on an experimental hybrid electrode allowing for simultaneous photonic or electrical neurostimulation and for electrical recording of evoked action potentials. The electrode includes three contacts and one optrode. The optrode is an opening in the cuff through which the tip of an optical fibre is held close to the epineurium. Two contacts provide action potential recording. The remaining contact, together with a remote subcutaneous electrode, is used for electric stimulation which allows periodical assessment of the viability of the nerve during the experiment. A 1470 nm light source was used to stimulate a mouse sciatic nerve. Neural action potentials were not successfully recorded because of the electrical noise so muscular activity was used to reflect the motor fibres stimulation. A recruitment curve was obtained by stimulating with photonic pulses of same power and increasing duration and recording the evoked muscular action potentials. Motor fibres can be recruited with radiant exposures between 0.05 and 0.23 J/cm2 for pulses in the 100 to 500 μs range. Successful stimulation at short duration and at a commercial wavelength is encouraging in the prospect of miniaturisation and practical applications. Motor fibres recruitment curve is a first step in an ongoing research work. Neural action potential acquisition will be improved, with aim to shed light on the mechanism of action potential initiation under photonic stimulation.

Tumors of peripheral nerves

International Nuclear Information System (INIS)

Ho, Michael; Lutz, Amelie M.

2017-01-01

Differentiation between malignant and benign tumors of peripheral nerves in the early stages is challenging; however, due to the unfavorable prognosis of malignant tumors early identification is required. To show the possibilities for detection, differential diagnosis and clinical management of peripheral nerve tumors by imaging appearance in magnetic resonance (MR) neurography. Review of current literature available in PubMed and MEDLINE, supplemented by the authors' own observations in clinical practice. Although not pathognomonic, several imaging features have been reported for a differentiation between distinct peripheral nerve tumors. The use of MR neurography enables detection and initial differential diagnosis in tumors of peripheral nerves. Furthermore, it plays an important role in clinical follow-up, targeted biopsy and surgical planning. (orig.) [de

Neural tissue engineering options for peripheral nerve regeneration.

Science.gov (United States)

Gu, Xiaosong; Ding, Fei; Williams, David F

2014-08-01

Tissue engineered nerve grafts (TENGs) have emerged as a potential alternative to autologous nerve grafts, the gold standard for peripheral nerve repair. Typically, TENGs are composed of a biomaterial-based template that incorporates biochemical cues. A number of TENGs have been used experimentally to bridge long peripheral nerve gaps in various animal models, where the desired outcome is nerve tissue regeneration and functional recovery. So far, the translation of TENGs to the clinic for use in humans has met with a certain degree of success. In order to optimize the TENG design and further approach the matching of TENGs with autologous nerve grafts, many new cues, beyond the traditional ones, will have to be integrated into TENGs. Furthermore, there is a strong requirement for monitoring the real-time dynamic information related to the construction of TENGs. The aim of this opinion paper is to specifically and critically describe the latest advances in the field of neural tissue engineering for peripheral nerve regeneration. Here we delineate new attempts in the design of template (or scaffold) materials, especially in the context of biocompatibility, the choice and handling of support cells, and growth factor release systems. We further discuss the significance of RNAi for peripheral nerve regeneration, anticipate the potential application of RNAi reagents for TENGs, and speculate on the possible contributions of additional elements, including angiogenesis, electrical stimulation, molecular inflammatory mediators, bioactive peptides, antioxidant reagents, and cultured biological constructs, to TENGs. Finally, we consider that a diverse array of physicochemical and biological cues must be orchestrated within a TENG to create a self-consistent coordinated system with a close proximity to the regenerative microenvironment of the peripheral nervous system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb.

Science.gov (United States)

Kowalska, Berta; Sudoł-Szopińska, Iwona

2012-06-01

The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the "elevator technique". All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the "Journal of Ultrasonography".

Reproducibility of current perception threshold with the Neurometer(®) vs the Stimpod NMS450 peripheral nerve stimulator in healthy volunteers: an observational study.

Science.gov (United States)

Tsui, Ban C H; Shakespeare, Timothy J; Leung, Danika H; Tsui, Jeremy H; Corry, Gareth N

2013-08-01

Current methods of assessing nerve blocks, such as loss of perception to cold sensation, are subjective at best. Transcutaneous nerve stimulation is an alternative method that has previously been used to measure the current perception threshold (CPT) in individuals with neuropathic conditions, and various devices to measure CPT are commercially available. Nevertheless, the device must provide reproducible results to be used as an objective tool for assessing nerve blocks. We recruited ten healthy volunteers to examine CPT reproducibility using the Neurometer(®) and the Stimpod NMS450 peripheral nerve stimulator. Each subject's CPT was determined for the median (second digit) and ulnar (fifth digit) nerve sensory distributions on both hands - with the Neurometer at 5 Hz, 250 Hz, and 2000 Hz and with the Stimpod at pulse widths of 0.1 msec, 0.3 msec, 0.5 msec, and 1.0 msec, both at 5 Hz and 2 Hz. Intraclass correlation coefficients (ICC) were also calculated to assess reproducibility; acceptable ICCs were defined as ≥ 0.4. The ICC values for the Stimpod ranged from 0.425-0.79, depending on pulse width, digit, and stimulation; ICCs for the Neurometer were 0.615 and 0.735 at 250 and 2,000 Hz, respectively. These values were considered acceptable; however, the Neurometer performed less efficiently at 5 Hz (ICCs for the second and fifth digits were 0.292 and 0.318, respectively). Overall, the Stimpod device displayed good to excellent reproducibility in measuring CPT in healthy volunteers. The Neurometer displayed poor reproducibility at low frequency (5 Hz). These results suggest that peripheral nerve stimulators may be potential devices for measuring CPT to assess nerve blocks.

Motor-commands decoding using peripheral nerve signals: a review

Science.gov (United States)

Hong, Keum-Shik; Aziz, Nida; Ghafoor, Usman

2018-06-01

During the last few decades, substantial scientific and technological efforts have been focused on the development of neuroprostheses. The major emphasis has been on techniques for connecting the human nervous system with a robotic prosthesis via natural-feeling interfaces. The peripheral nerves provide access to highly processed and segregated neural command signals from the brain that can in principle be used to determine user intent and control muscles. If these signals could be used, they might allow near-natural and intuitive control of prosthetic limbs with multiple degrees of freedom. This review summarizes the history of neuroprosthetic interfaces and their ability to record from and stimulate peripheral nerves. We also discuss the types of interfaces available and their applications, the kinds of peripheral nerve signals that are used, and the algorithms used to decode them. Finally, we explore the prospects for future development in this area.

Normal and sonographic anatomy of selected peripheral nerves. Part III: Peripheral nerves of the lower limb

Directory of Open Access Journals (Sweden)

Berta Kowalska

2012-06-01

Full Text Available The ultrasonographic examination is currently increasingly used in imaging peripheral nerves, serving to supplement the physical examination, electromyography and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive and well-tolerated by patients. The typical ultrasonographic picture of peripheral nerves as well as the examination technique have been discussed in part I of this article series, following the example of the median nerve. Part II of the series presented the normal anatomy and the technique for examining the peripheral nerves of the upper limb. This part of the article series focuses on the anatomy and technique for examining twelve normal peripheral nerves of the lower extremity: the iliohypogastric and ilioinguinal nerves, the lateral cutaneous nerve of the thigh, the pudendal, sciatic, tibial, sural, medial plantar, lateral plantar, common peroneal, deep peroneal and superficial peroneal nerves. It includes diagrams showing the proper positioning of the sonographic probe, plus USG images of the successively discussed nerves and their surrounding structures. The ultrasonographic appearance of the peripheral nerves in the lower limb is identical to the nerves in the upper limb. However, when imaging the lower extremity, convex probes are more often utilized, to capture deeply-seated nerves. The examination technique, similarly to that used in visualizing the nerves of upper extremity, consists of locating the nerve at a characteristic anatomic reference point and tracking it using the “elevator technique”. All 3 parts of the article series should serve as an introduction to a discussion of peripheral nerve pathologies, which will be presented in subsequent issues of the “Journal of Ultrasonography”.

Nerve ultrasound shows subclinical peripheral nerve involvement in neurofibromatosis type 2.

Science.gov (United States)

Telleman, Johan A; Stellingwerff, Menno D; Brekelmans, Geert J; Visser, Leo H

2018-02-01

Neurofibromatosis type 2 (NF2) is mainly associated with central nervous system (CNS) tumors. Peripheral nerve involvement is described in symptomatic patients, but evidence of subclinical peripheral nerve involvement is scarce. We conducted a cross-sectional pilot study in 2 asymptomatic and 3 minimally symptomatic patients with NF2 to detect subclinical peripheral nerve involvement. Patients underwent clinical examination, nerve conduction studies (NCS), and high-resolution ultrasonography (HRUS). A total of 30 schwannomas were found, divided over 20 nerve segments (33.9% of all investigated nerve segments). All patients had at least 1 schwannoma. Schwannomas were identified with HRUS in 37% of clinically unaffected nerve segments and 50% of nerve segments with normal NCS findings. HRUS shows frequent subclinical peripheral nerve involvement in NF2. Clinicians should consider peripheral nerve involvement as a cause of weakness and sensory loss in the extremities in patients with this disease. Muscle Nerve 57: 312-316, 2018. © 2017 Wiley Periodicals, Inc.

Right-sided vagus nerve stimulation inhibits induced spinal cord seizures.

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Tubbs, R Shane; Salter, E George; Killingsworth, Cheryl; Rollins, Dennis L; Smith, William M; Ideker, Raymond E; Wellons, John C; Blount, Jeffrey P; Oakes, W Jerry

2007-01-01

We have previously shown that left-sided vagus nerve stimulation results in cessation of induced spinal cord seizures. To test our hypothesis that right-sided vagus nerve stimulation will also abort seizure activity, we have initiated seizures in the spinal cord and then performed right-sided vagus nerve stimulation in an animal model. Four pigs were anesthetized and placed in the lateral position and a small laminectomy performed in the lumbar region. Topical penicillin, a known epileptogenic drug to the cerebral cortex and spinal cord, was next applied to the dorsal surface of the exposed cord. With the exception of the control animal, once seizure activity was discernible via motor convulsion or increased electrical activity, the right vagus nerve previously isolated in the neck was stimulated. Following multiple stimulations of the vagus nerve and with seizure activity confirmed, the cord was transected in the midthoracic region and vagus nerve stimulation performed. Right-sided vagus nerve stimulation resulted in cessation of spinal cord seizure activity in all animals. Transection of the spinal cord superior to the site of seizure induction resulted in the ineffectiveness of vagus nerve stimulation in causing cessation of seizure activity in all study animals. As with left-sided vagus nerve stimulation, right-sided vagus nerve stimulation results in cessation of induced spinal cord seizures. Additionally, the effects of right-sided vagus nerve stimulation on induced spinal cord seizures involve descending spinal pathways. These data may aid in the development of alternative mechanisms for electrical stimulation for patients with medically intractable seizures and add to our knowledge regarding the mechanism for seizure cessation following peripheral nerve stimulation.

Nanofiber Nerve Guide for Peripheral Nerve Repair and Regeneration

Science.gov (United States)

2016-04-01

1 Award Number: W81XWH-11-2-0047 TITLE: Nanofiber Nerve Guide for Peripheral Nerve Repair and Regeneration PRINCIPAL INVESTIGATOR: Ahmet Höke...TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-11-2-0047 Nanofiber nerve guide for peripheral nerve repair and regeneration 5b. GRANT NUMBER...goal of this collaborative research project was to develop next generation engineered nerve guide conduits (NGCs) with aligned nanofibers and

Peripheral nerve field stimulation (PNFS) in chronic low back pain: a prospective multicenter study.

Science.gov (United States)

Kloimstein, Herwig; Likar, Rudolf; Kern, Michael; Neuhold, Josef; Cada, Miroslav; Loinig, Nadja; Ilias, Wilfried; Freundl, Brigitta; Binder, Heinrich; Wolf, Andreas; Dorn, Christian; Mozes-Balla, Eva Maria; Stein, Rolf; Lappe, Ivo; Sator-Katzenschlager, Sabine

2014-02-01

The goal of this study was to evaluate the long-term efficacy and safety of peripheral nerve field stimulation (PNFS) for chronic low back pain (cLBP). In this prospective, multicenter observational study, 118 patients were admitted to 11 centers throughout Austria and Switzerland. After a screening visit, all patients underwent a trial stimulation period of at least seven days before implantation of the permanent system. Leads were placed in the subcutaneous tissues of the lower back directly in the region of greatest pain. One hundred five patients were implanted with a permanent stimulating system. Patients' evaluation of pain and functional levels were completed before implantation and one, three, and six months after implantation. Adverse events, medication usage, and coverage of the painful area and predictive value of transcutaneous electrical nerve stimulation (TENS) were monitored. All pain and quality-of-life measures showed statistically significant improvement during the treatment period. These included the average pain visual analog scale, the Oswestry Disability Questionnaire, the Becks Depression Inventory, and the Short Form-12 item Health survey. Additionally, medication usage with opioids, nonsteroidal anti-inflammatory drugs, and anti-convulsants showed a highly significant reduction. Complications requiring surgical intervention were reported in 9.6% of the patients. The degree of coverage of painful areas seems to be an important criterion for efficacy of PNFS, whereas TENS is presumably no predictor. This prospective, multicenter study confirms that PNFS is an effective therapy for the management of cLBP. Significant improvements in many aspects of the pain condition were measured, and complications were minimal. © 2013 International Neuromodulation Society.

Measurement of wavefront aberrations in cortex and peripheral nerve using a two-photon excitation guidestar

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Futia, Gregory L.; Fontaine, Arjun; McCullough, Connor; Ozbay, Baris N.; George, Nickolas M.; Caldwell, John; Restrepo, Diego; Weir, Richard; Gibson, Emily A.

2018-02-01

Neural-machine interfaces using optogenetics are of interest due to their minimal invasiveness and potential for parallel read in and read out of activity. One possible biological target for such an interface is the peripheral nerve, where axonlevel imaging or stimulation could greatly improve interfacing with artificial limbs or enable neuron/fascicle level neuromodulation in the vagus nerve. Two-photon imaging has been successful in imaging brain activity using genetically encoded calcium or voltage indicators, but in the peripheral nerve, this is severely limited by scattering and aberrations from myelin. We employ a Shack-Hartman wavefront sensor and two-photon excitation guidestar to quantify optical scattering and aberrations in peripheral nerves and cortex. The sciatic and vagus nerves, and cortex from a ChAT-Cre ChR-eYFP transgenic mouse were excised and imaged directly. In peripheral nerves, defocus was the strongest aberration followed by astigmatism and coma. Peripheral nerve had orders of magnitude higher aberration compared with cortex. These results point to the potential of adaptive optics for increasing the depth of two-photon access into peripheral nerves.

The surgery of peripheral nerves (including tumors)

DEFF Research Database (Denmark)

Fugleholm, Kåre

2013-01-01

Surgical pathology of the peripheral nervous system includes traumatic injury, entrapment syndromes, and tumors. The recent significant advances in the understanding of the pathophysiology and cellular biology of peripheral nerve degeneration and regeneration has yet to be translated into improved...... surgical techniques and better outcome after peripheral nerve injury. Decision making in peripheral nerve surgery continues to be a complex challenge, where the mechanism of injury, repeated clinical evaluation, neuroradiological and neurophysiological examination, and detailed knowledge of the peripheral...... nervous system response to injury are prerequisite to obtain the best possible outcome. Surgery continues to be the primary treatment modality for peripheral nerve tumors and advances in adjuvant oncological treatment has improved outcome after malignant peripheral nerve tumors. The present chapter...

A Model of Electrically Stimulated Auditory Nerve Fiber Responses with Peripheral and Central Sites of Spike Generation

DEFF Research Database (Denmark)

Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

2017-01-01

. A single ANF is modeled as a network of two exponential integrateand-fire point-neuron models, referred to as peripheral and central axons of the ANF. The peripheral axon is excited by the cathodic charge, inhibited by the anodic charge, and exhibits longer spike latencies than the central axon......A computational model of cat auditory nerve fiber (ANF) responses to electrical stimulation is presented. The model assumes that (1) there exist at least two sites of spike generation along the ANF and (2) both an anodic (positive) and a cathodic (negative) charge in isolation can evoke a spike......; the central axon is excited by the anodic charge, inhibited by the cathodic charge, and exhibits shorter spike latencies than the peripheral axon. The model also includes subthreshold and suprathreshold adaptive feedback loops which continuously modify the membrane potential and can account for effects...

Expression patterns and role of PTEN in rat peripheral nerve development and injury.

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Chen, Hui; Xiang, Jianping; Wu, Junxia; He, Bo; Lin, Tao; Zhu, Qingtang; Liu, Xiaolin; Zheng, Canbin

2018-05-29

Studies have suggested that phosphatase and tensin homolog (PTEN) plays an important role in neuroprotection and neuronal regeneration. To better understand the potential role of PTEN with respect to peripheral nerve development and injury, we investigated the expression pattern of PTEN at different stages of rat peripheral nerve development and injury and subsequently assessed the effect of pharmacological inhibition of PTEN using bpV(pic) on axonal regeneration in a rat sciatic nerve crush injury model. During the early stages of development, PTEN exhibits low expression in neuronal cell bodies and axons. From embryonic day (E) 18.5 and postnatal day (P)5 to adult, PTEN protein becomes more detectable, with high expression in the dorsal root ganglia (DRG) and axons. PTEN expression is inhibited in peripheral nerves, preceding myelination during neuronal development and remyelination after acute nerve injury. Low PTEN expression after nerve injury promotes Akt/mammalian target of rapamycin (mTOR) signaling pathway activity. In vivo pharmacological inhibition of PTEN using bpV(pic) promoted axonal regrowth, increased the number of myelinated nerve fibers, improved locomotive recovery and enhanced the amplitude response and nerve conduction velocity following stimulation in a rat sciatic nerve crush injury model. Thus, we suggest that PTEN may play potential roles in peripheral nerve development and regeneration and that inhibition of PTEN expression is beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Copyright © 2018 Elsevier B.V. All rights reserved.

Peripheral nerve conduits: technology update

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Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

2014-01-01

Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

Silk fibroin enhances peripheral nerve regeneration by improving vascularization within nerve conduits.

Science.gov (United States)

Wang, Chunyang; Jia, Yachao; Yang, Weichao; Zhang, Cheng; Zhang, Kuihua; Chai, Yimin

2018-07-01

Silk fibroin (SF)-based nerve conduits have been widely used to bridge peripheral nerve defects. Our previous study showed that nerve regeneration in a SF-blended poly (l-lactide-co-ɛ-caprolactone) [P(LLA-CL)] nerve conduit is better than that in a P(LLA-CL) conduit. However, the involved mechanisms remain unclarified. Because angiogenesis within a nerve conduit plays an important role in nerve regeneration, vascularization of SF/P(LLA-CL) and P(LLA-CL) conduits was compared both in vitro and in vivo. In the present study, we observed that SF/P(LLA-CL) nanofibers significantly promoted fibroblast proliferation, and vascular endothelial growth factor secreted by fibroblasts seeded in SF/P(LLA-CL) nanofibers was more than seven-fold higher than that in P(LLA-CL) nanofibers. Conditioned medium of fibroblasts in the SF/P(LLA-CL) group stimulated more human umbilical vein endothelial cells (HUVEC) to form capillary-like networks and promoted faster HUVEC migration. The two kinds of nerve conduits were used to bridge 10-mm-length nerve defects in rats. At 3 weeks of reparation, the blood vessel area in the SF/P(LLA-CL) group was significantly larger than that in the P(LLA-CL) group. More regenerated axons and Schwann cells were also observed in the SF/P(LLA-CL) group, which was consistent with the results of blood vessels. Collectively, our data revealed that the SF/P(LLA-CL) nerve conduit enhances peripheral nerve regeneration by improving angiogenesis within the conduit. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2070-2077, 2018. © 2018 Wiley Periodicals, Inc.

Transverse tripolar stimulation of peripheral nerve: a modelling study of spatial selectivity.

Science.gov (United States)

Deurloo, K E; Holsheimer, J; Boom, H B

1998-01-01

Various anode-cathode configurations in a nerve cuff are modelled to predict their spatial selectivity characteristics for functional nerve stimulation. A 3D volume conductor model of a monofascicular nerve is used for the computation of stimulation-induced field potentials, whereas a cable model of myelinated nerve fibre is used for the calculation of the excitation thresholds of fibres. As well as the usual configurations (monopole, bipole, longitudinal tripole, 'steering' anode), a transverse tripolar configuration (central cathode) is examined. It is found that the transverse tripole is the only configuration giving convex recruitment contours and therefore maximises activation selectivity for a small (cylindrical) bundle of fibres in the periphery of a monofascicular nerve trunk. As the electrode configuration is changed to achieve greater selectivity, the threshold current increases. Therefore threshold currents for fibre excitation with a transverse tripole are relatively high. Inverse recruitment is less extreme than for the other configurations. The influences of several geometrical parameters and model conductivities of the transverse tripole on selectivity and threshold current are analysed. In chronic implantation, when electrodes are encapsulated by a layer of fibrous tissue, threshold currents are low, whereas the shape of the recruitment contours in transverse tripolar stimulation does not change.

Normal and sonographic anatomy of selected peripheral nerves. Part II: Peripheral nerves of the upper limb

Directory of Open Access Journals (Sweden)

Berta Kowalska

2012-06-01

Full Text Available The ultrasonographic examination is frequently used for imaging peripheral nerves. It serves to supplement the physical examination, electromyography, and magnetic resonance imaging. As in the case of other USG imaging studies, the examination of peripheral nerves is non-invasive, well-tolerated by patients, and relatively inexpensive. Part I of this article series described in detail the characteristic USG picture of peripheral nerves and the proper examination technique, following the example of the median nerve. This nerve is among the most often examined peripheral nerves of the upper limb. This part presents describes the normal anatomy and ultrasound picture of the remaining large nerve branches in the upper extremity and neck – the spinal accessory nerve, the brachial plexus, the suprascapular, axillary, musculocutaneous, radial and ulnar nerves. Their normal anatomy and ultrasonographic appearance have been described, including the division into individual branches. For each of them, specific reference points have been presented, to facilitate the location of the set trunk and its further monitoring. Sites for the application of the ultrasonographic probe at each reference point have been indicated. In the case of the ulnar nerve, the dynamic component of the examination was emphasized. The text is illustrated with images of probe positioning, diagrams of the normal course of the nerves as well as a series of ultrasonographic pictures of normal nerves of the upper limb. This article aims to serve as a guide in the ultrasound examination of the peripheral nerves of the upper extremity. It should be remembered that a thorough knowledge of the area’s topographic anatomy is required for this type of examination.

Wireless peripheral nerve stimulation for complex regional pain syndrome type I of the upper extremity: a case illustration introducing a novel technology.

Science.gov (United States)

Herschkowitz, Daniel; Kubias, Jana

2018-04-13

Complex regional pain syndrome (CRPS) is a debilitating painful disorder, cryptic in its pathophysiology and refractory condition with limited therapeutic options. Type I CRPS with its variable relationship to trauma has often no discernible fractures or nerve injuries and remains enigmatic in its response to conservative treatment as well as the other limited interventional therapies. Neuromodulation in the form of spinal cord and dorsal root ganglion stimulation (SCS, DRGS) has shown encouraging results, especially of causalgia or CRPS I of lower extremities. Upper extremity CRPS I is far more difficult. To report a case of upper extremity CRPS I treated by wireless peripheral nerve stimulation (WPNS) for its unique features and minimally invasive technique. The system does not involve implantation of battery or its connections. A 47 year old female patient presented with refractory CRPS I following a blunt trauma to her right forearm. As interventional treatment in the form of local anesthetics (Anesthesia of peripheral branches of radial nerve) and combined infusions of ketamine/lidocaine failed to provide any significant relief she opted for WPNS treatment. Based on the topographic distribution, two electrodes (Stimwave Leads: FR4A-RCV-A0 with tines, Generation 1 and FR4A-RCV-B0 with tines, Generation 1), were placed along the course of radial and median nerves under ultrasonography monitoring and guided by intraoperative stimulation. This procedure did not involve implantation of extension cables or the power source. At a frequency of 60 Hz and 300 μs the stimulation induced paresthesia along the distribution of the nerves. Therapeutic relief was observed with high frequency (HF) stimulation (HF 10 kHz/32 μs, 2.0 mA) reducing her pain from a visual analogue scale (VAS) score of 7-4 postoperatively. Three HF stimulations programs were provided at the time of discharge, as she improved in her sensory impairment to touch, pressure and temperature at her first

Nerve Regeneration in the Peripheral Nervous System versus the Central Nervous System and the Relevance to Speech and Hearing after Nerve Injuries

Science.gov (United States)

Gordon, Tessa; Gordon, Karen

2010-01-01

Schwann cells normally form myelin sheaths around axons in the peripheral nervous system (PNS) and support nerve regeneration after nerve injury. In contrast, nerve regeneration in the central nervous system (CNS) is not supported by the myelinating cells known as oligodendrocytes. We have found that: 1) low frequency electrical stimulation can be…

Recruitment order of quadriceps motor units: femoral nerve vs. direct quadriceps stimulation.

Science.gov (United States)

Rodriguez-Falces, Javier; Place, Nicolas

2013-12-01

To investigate potential differences in the recruitment order of motor units (MUs) in the quadriceps femoris when electrical stimulation is applied over the quadriceps belly versus the femoral nerve. M-waves and mechanical twitches were evoked using femoral nerve stimulation and direct quadriceps stimulation of gradually increasing intensity from 20 young, healthy subjects. Recruitment order was investigated by analysing the time-to-peak twitch and the time interval from the stimulus artefact to the M-wave positive peak (M-wave latency) for the vastus medialis (VM) and vastus lateralis (VL) muscles. During femoral nerve stimulation, time-to-peak twitch and M-wave latency decreased consistently (P  0.05). For the VM muscle, M-wave latency decreased with increasing stimulation level for both femoral nerve and direct quadriceps stimulation, whereas, for the VL muscle, the variation of M-wave latency with stimulus intensity was different for the two stimulation geometries (P recruitment order during direct quadriceps stimulation was more complex, depending ultimately on the architecture of the peripheral nerve and its terminal branches below the stimulating electrodes for each muscle. For the VM, MUs were orderly recruited for both stimulation geometries, whereas, for the VL muscle, MUs were orderly recruited for femoral nerve stimulation, but followed no particular order for direct quadriceps stimulation.

Synovial sarcoma mimicking benign peripheral nerve sheath tumor

Energy Technology Data Exchange (ETDEWEB)

Larque, Ana B.; Nielsen, G.P.; Chebib, Ivan [Massachusetts General Hospital and Harvard Medical School, Department of Pathology, Boston, MA (United States); Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States)

2017-11-15

To assess the radiographic and clinicopathologic features of synovial sarcoma of the nerve that were clinically or radiologically interpreted as benign peripheral nerve sheath tumor. Five patients with synovial sarcoma arising from the peripheral nerve and interpreted clinically and radiologically as peripheral nerve sheath tumors were identified. Clinicopathologic and imaging features were evaluated. There were three females and two males, ranging in age from 28 to 50 (mean 35.8) years. Most patients (4/5) complained of a mass, discomfort or pain. MR images demonstrated a heterogeneous, enhancing, soft tissue mass contiguous with the neurovascular bundle. On histologic examination, most tumors were monophasic synovial sarcoma (4/5). At the time of surgery, all tumors were noted to arise along or within a peripheral nerve. All patients were alive with no evidence of disease with median follow-up of 44 (range 32-237) months. For comparison, approximately 775 benign peripheral nerve sheath tumors of the extremities were identified during the same time period. Primary synovial sarcoma of the nerve can mimic peripheral nerve sheath tumors clinically and on imaging and should be included in the differential diagnosis for tumors arising from peripheral nerves. (orig.)

Use of tripolar electrodes for minimization of current spread in uncut peripheral nerve stimulation.

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Ohsawa, Ichiro; Inui, Koji

2009-05-01

The electrical stimulation of an uncut peripheral nerve requires a countermeasure to avoid the spread of current through a loop pathway formed outside the electrode array. Here the use of tripolar electrodes (TE) is proposed. By binding the two end poles, current spread through the loop pathway can theoretically be eliminated since both end poles are held equipotential. Experimentally, we tested the validity of this approach. In chloralose-urethane anesthetized rats, the left cervical vagus (LCV) was placed on TE which could function as such or as bipolar electrodes (BE) by the use of a selector switch. The spread of current to the adjacent tissues (rectus capitis muscle underlying the LCV, and the right cervical vagus (RCV) incised and translocated beside the target, LCV) was compared between TE and BE. When the stimulus intensity was increased, contraction occurred in the capitis muscle with BE, but not TE. Compound spike potentials of A fiber origin were evoked in the non-target RCV on high-intensity stimulation with BE, but not TE. Constant voltage stimulation of the LCV with TE produced bradycardia of the same magnitude as that with BE. In conclusion, constant voltage stimulation using TE can minimize current spread without changing the stimulus's effects.

Dynamic impact of brief electrical nerve stimulation on the neural immune axis-polarization of macrophages toward a pro-repair phenotype in demyelinated peripheral nerve.

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McLean, Nikki A; Verge, Valerie M K

2016-09-01

Demyelinating peripheral nerves are infiltrated by cells of the monocyte lineage, including macrophages, which are highly plastic, existing on a continuum from pro-inflammatory M1 to pro-repair M2 phenotypic states. Whether one can therapeutically manipulate demyelinated peripheral nerves to promote a pro-repair M2 phenotype remains to be elucidated. We previously identified brief electrical nerve stimulation (ES) as therapeutically beneficial for remyelination, benefits which include accelerated clearance of macrophages, making us theorize that ES alters the local immune response. Thus, the impact of ES on the immune microenvironment in the zone of demyelination was examined. Adult male rat tibial nerves were focally demyelinated via 1% lysophosphatidyl choline (LPC) injection. Five days later, half underwent 1 hour 20 Hz sciatic nerve ES proximal to the LPC injection site. ES had a remarkable and significant impact, shifting the macrophage phenotype from predominantly pro-inflammatory/M1 toward a predominantly pro-repair/M2 one, as evidenced by an increased incidence of expression of M2-associated phenotypic markers in identified macrophages and a decrease in M1-associated marker expression. This was discernible at 3 days post-ES (8 days post-LPC) and continued at the 5 day post-ES (10 days post-LPC) time point examined. ES also affected chemokine (C-C motif) ligand 2 (CCL2; aka MCP-1) expression in a manner that correlated with increases and decreases in macrophage numbers observed in the demyelination zone. The data establish that briefly increasing neuronal activity favorably alters the immune microenvironment in demyelinated nerve, rapidly polarizing macrophages toward a pro-repair phenotype, a beneficial therapeutic concept that may extend to other pathologies. GLIA 2016;64:1546-1561. © 2016 Wiley Periodicals, Inc.

Presence and Absence of Muscle Contraction Elicited by Peripheral Nerve Electrical Stimulation Differentially Modulate Primary Motor Cortex Excitability

Science.gov (United States)

Sasaki, Ryoki; Kotan, Shinichi; Nakagawa, Masaki; Miyaguchi, Shota; Kojima, Sho; Saito, Kei; Inukai, Yasuto; Onishi, Hideaki

2017-01-01

Modulation of cortical excitability by sensory inputs is a critical component of sensorimotor integration. Sensory afferents, including muscle and joint afferents, to somatosensory cortex (S1) modulate primary motor cortex (M1) excitability, but the effects of muscle and joint afferents specifically activated by muscle contraction are unknown. We compared motor evoked potentials (MEPs) following median nerve stimulation (MNS) above and below the contraction threshold based on the persistence of M-waves. Peripheral nerve electrical stimulation (PES) conditions, including right MNS at the wrist at 110% motor threshold (MT; 110% MNS condition), right MNS at the index finger (sensory digit nerve stimulation [DNS]) with stimulus intensity approximately 110% MNS (DNS condition), and right MNS at the wrist at 90% MT (90% MNS condition) were applied. PES was administered in a 4 s ON and 6 s OFF cycle for 20 min at 30 Hz. In Experiment 1 (n = 15), MEPs were recorded from the right abductor pollicis brevis (APB) before (baseline) and after PES. In Experiment 2 (n = 15), M- and F-waves were recorded from the right APB. Stimulation at 110% MNS at the wrist evoking muscle contraction increased MEP amplitudes after PES compared with those at baseline, whereas DNS at the index finger and 90% MNS at the wrist not evoking muscle contraction decreased MEP amplitudes after PES. M- and F-waves, which reflect spinal cord or muscular and neuromuscular junctions, did not change following PES. These results suggest that muscle contraction and concomitant muscle/joint afferent inputs specifically enhance M1 excitability. PMID:28392766

The use of the rat as a model for studying peripheral nerve regeneration and sprouting after complete and partial nerve injuries.

Science.gov (United States)

Gordon, Tessa; Borschel, Gregory H

2017-01-01

Rat models of complete and partial injuries are the most frequently used models for analysis of the cellular and molecular processes of nerve regeneration and axon sprouting. Studies of nerve regeneration and axon sprouting after complete and partial nerve injuries, respectively, are reviewed. Special consideration is made of the peripheral nerves chosen for the studies and the outcome measures that were utilized in the studies. The studies have made important contributions to our knowledge of the degenerative and regenerative processes that occur after the peripheral nerve injuries, why functional recovery is frequently compromised after delayed surgery, the positive effects of neurotrophic factors on nerve regeneration after delayed nerve repair or after insertion of autografts between transected nerve, and how axon regeneration may be accelerated by brief periods of electrical stimulation and/or by administration of androgens. Copyright © 2016 Elsevier Inc. All rights reserved.

Short-term low-frequency electrical stimulation enhanced remyelination of injured peripheral nerves by inducing the promyelination effect of brain-derived neurotrophic factor on Schwann cell polarization.

Science.gov (United States)

Wan, Lidan; Xia, Rong; Ding, Wenlong

2010-09-01

Electrical stimulation (ES) has been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. However, the effect of ES on peripheral remyelination after nerve damage has been investigated less well, and the mechanism underlying its action remains unclear. In the present study, the crush-injured sciatic nerves in rats were subjected to 1 hr of continuous ES (20 Hz, 100 microsec, 3 V). Electron microscopy and nerve morphometry were performed to investigate the extent of regenerated nerve myelination. The expression profiles of P0, Par-3, and brain-derived neurotrophic factor (BDNF) in the injuried sciatic nerves and in the dorsal root ganglion neuron/Schwann cell cocultures were examined by Western blotting. Par-3 localization in the sciatic nerves was determined by immunohistochemistry to demonstrate Schwann cell polarization during myelination. We reported that 20-Hz ES increased the number of myelinated fibers and the thickness myelin sheath at 4 and 8 weeks postinjury. P0 level in the ES-treated groups, both in vitro and in vivo, was enhanced compared with the controls. The earlier peak of Par-3 in the ES-treated groups indicated an earlier initiation of Schwann cell myelination. Additionally, ES significantly elevated BDNF expression in nerve tissues and in cocultures. ES on the site of nerve injury potentiates axonal regrowth and myelin maturation during peripheral nerve regeneration. Furthermore, the therapeutic actions of ES on myelination are mediated via enhanced BDNF signals, which drive the promyelination effect on Schwann cells at the onset of myelination.

Label-free photoacoustic microscopy of peripheral nerves

Science.gov (United States)

Matthews, Thomas Paul; Zhang, Chi; Yao, Da-Kang; Maslov, Konstantin; Wang, Lihong V.

2014-01-01

Peripheral neuropathy is a common neurological problem that affects millions of people worldwide. Diagnosis and treatment of this condition are often hindered by the difficulties in making objective, noninvasive measurements of nerve fibers. Photoacoustic microscopy (PAM) has the ability to obtain high resolution, specific images of peripheral nerves without exogenous contrast. We demonstrated the first proof-of-concept imaging of peripheral nerves using PAM. As validated by both standard histology and photoacoustic spectroscopy, the origin of photoacoustic signals is myelin, the primary source of lipids in the nerves. An extracted sciatic nerve sandwiched between two layers of chicken tissue was imaged by PAM to mimic the in vivo case. Ordered fibrous structures inside the nerve, caused by the bundles of myelin-coated axons, could be observed clearly. With further technical improvements, PAM can potentially be applied to monitor and diagnose peripheral neuropathies.

Accelerating axon growth to overcome limitations in functional recovery after peripheral nerve injury.

Science.gov (United States)

Gordon, Tessa; Chan, K Ming; Sulaiman, Olawale A R; Udina, Esther; Amirjani, Nasim; Brushart, Thomas M

2009-10-01

Injured peripheral nerves regenerate at very slow rates. Therefore, proximal injury sites such as the brachial plexus still present major challenges, and the outcomes of conventional treatments remain poor. This is in part attributable to a progressive decline in the Schwann cells' ability to provide a supportive milieu for the growth cone to extend and to find the appropriate target. These challenges are compounded by the often considerable delay of regeneration across the site of nerve laceration. Recently, low-frequency electrical stimulation (as brief as an hour) has shown promise, as it significantly accelerated regeneration in animal models through speeding of axon growth across the injury site. To test whether this might be a useful clinical tool, we carried out a randomized controlled trial in patients who had experienced substantial axonal loss in the median nerve owing to severe compression in the carpal tunnel. To further elucidate the potential mechanisms, we applied rolipram, a cyclic adenosine monophosphate agonist, to rats after axotomy of the femoral nerve. We demonstrated that effects similar to those observed in animal studies could also be attained in humans. The mechanisms of action of electrical stimulation likely operate through up-regulation of neurotrophic factors and cyclic adenosine monophosphate. Indeed, the application of rolipram significantly accelerated nerve regeneration. With new mechanistic insights into the influencing factors of peripheral nerve regeneration, the novel treatments described above could form part of an armament of synergistic therapies that could make a meaningful difference to patients with peripheral nerve injuries.

Malignant peripheral nerve sheath tumor of the oculomotor nerve

DEFF Research Database (Denmark)

Kozic, D; Nagulic, M; Ostojic, J

2006-01-01

We present the short-term follow-up magnetic resonance (MR) studies and 1H-MR spectroscopy in a child with malignant peripheral nerve sheath tumor of the oculomotor nerve associated with other less aggressive cranial nerve schwannomas. The tumor revealed perineural extension and diffuse nerve...

Electrical and transcranial magnetic stimulation of the facial nerve: diagnostic relevance in acute isolated facial nerve palsy.

Science.gov (United States)

Happe, Svenja; Bunten, Sabine

2012-01-01

Unilateral facial weakness is common. Transcranial magnetic stimulation (TMS) allows identification of a conduction failure at the level of the canalicular portion of the facial nerve and may help to confirm the diagnosis. We retrospectively analyzed 216 patients with the diagnosis of peripheral facial palsy. The electrophysiological investigations included the blink reflex, preauricular electrical stimulation and the response to TMS at the labyrinthine part of the canalicular proportion of the facial nerve within 3 days after symptom onset. A similar reduction or loss of the TMS amplitude (p facial palsy without being specific for Bell's palsy. These data shed light on the TMS-based diagnosis of peripheral facial palsy, an ability to localize the site of lesion within the Fallopian channel regardless of the underlying pathology. Copyright © 2012 S. Karger AG, Basel.

Ultrasonic stimulation of peripheral nervous tissue: an investigation into mechanisms

International Nuclear Information System (INIS)

Wright, C J; Saffari, N; Rothwell, J

2015-01-01

Neuro-stimulation has wide ranging clinical and research potential but this is currently limited either by low resolution, penetration or by highly invasive procedures. It has been reported in previous studies that ultrasound is able to elicit a neuro-stimulatory effect at a higher resolution than other non-invasive approaches but both the underlying mechanism that makes this possible and the practical details of how it can be implemented are still poorly understood. The current study has identified the main issues that need to be resolved in the field, proposing several different approaches to tackling these areas. An isolated in vitro peripheral nerve bundle was chosen as a simple model to demonstrate and investigate the neuro-stimulatory effect after preliminary results showed successful stimulation in a skin-nerve preparation. Early results from the nerve bundle show successful neurostimulation, indicating that structures in the peripheral nerve axon are sensitive to ultrasound. Further research using this model should reveal more precisely what structures are being affected and how to optimise the effect, helping to inform the design of future procedures and devices used in in vivo applications

Sacral nerve stimulation increases activation of the primary somatosensory cortex by anal canal stimulation in an experimental model.

LENUS (Irish Health Repository)

Griffin, K M

2011-08-01

Sacral and posterior tibial nerve stimulation may be used to treat faecal incontinence; however, the mechanism of action is unknown. The aim of this study was to establish whether sensory activation of the cerebral cortex by anal canal stimulation was increased by peripheral neuromodulation.

Tissue-engineered spiral nerve guidance conduit for peripheral nerve regeneration.

Science.gov (United States)

Chang, Wei; Shah, Munish B; Lee, Paul; Yu, Xiaojun

2018-06-01

Recently in peripheral nerve regeneration, preclinical studies have shown that the use of nerve guidance conduits (NGCs) with multiple longitudinally channels and intra-luminal topography enhance the functional outcomes when bridging a nerve gap caused by traumatic injury. These features not only provide guidance cues for regenerating nerve, but also become the essential approaches for developing a novel NGC. In this study, a novel spiral NGC with aligned nanofibers and wrapped with an outer nanofibrous tube was first developed and investigated. Using the common rat sciatic 10-mm nerve defect model, the in vivo study showed that a novel spiral NGC (with and without inner nanofibers) increased the successful rate of nerve regeneration after 6 weeks recovery. Substantial improvements in nerve regeneration were achieved by combining the spiral NGC with inner nanofibers and outer nanofibrous tube, based on the results of walking track analysis, electrophysiology, nerve histological assessment, and gastrocnemius muscle measurement. This demonstrated that the novel spiral NGC with inner aligned nanofibers and wrapped with an outer nanofibrous tube provided a better environment for peripheral nerve regeneration than standard tubular NGCs. Results from this study will benefit for future NGC design to optimize tissue-engineering strategies for peripheral nerve regeneration. We developed a novel spiral nerve guidance conduit (NGC) with coated aligned nanofibers. The spiral structure increases surface area by 4.5 fold relative to a tubular NGC. Furthermore, the aligned nanofibers was coated on the spiral walls, providing cues for guiding neurite extension. Finally, the outside of spiral NGC was wrapped with randomly nanofibers to enhance mechanical strength that can stabilize the spiral NGC. Our nerve histological data have shown that the spiral NGC had 50% more myelinated axons than a tubular structure for nerve regeneration across a 10 mm gap in a rat sciatic nerve

Peripheral nerve involvement in Bell's palsy

Directory of Open Access Journals (Sweden)

J. A. Bueri

1984-12-01

Full Text Available A group of patients with Bell's palsy were studied in order to disclose the presence of subclinical peripheral nerve involvement. 20 patients, 8 male and 12 female, with recent Bell's palsy as their unique disease were examined, in all cases other causes of polyneuropathy were ruled out. Patients were investigated with CSF examination, facial nerve latencies in the affected and in the sound sides, and maximal motor nerve conduction velocities, as well as motor terminal latencies from the right median and peroneal nerves. CSF laboratory examination was normal in all cases. Facial nerve latencies were abnormal in all patients in the affected side, and they differed significantly from those of control group in the clinically sound side. Half of the patients showed abnormal values in the maximal motor nerve conduction velocities and motor terminal latencies of the right median and peroneal nerves. These results agree with previous reports which have pointed out that other cranial nerves may be affected in Bell's palsy. However, we have found a higher frequency of peripheral nerve involvement in this entity. These findings, support the hypothesis that in some patients Bell's palsy is the component of a more widespread disease, affecting other cranial and peripheral nerves.

Evaluation of phrenic nerve and diaphragm function with peripheral nerve stimulation and M-mode ultrasonography in potential pediatric phrenic nerve or diaphragm pacing candidates.

Science.gov (United States)

Skalsky, Andrew J; Lesser, Daniel J; McDonald, Craig M

2015-02-01

Assessing phrenic nerve function in the setting of diaphragmatic paralysis in diaphragm pacing candidates can be challenging. Traditional imaging modalities and electrodiagnostic evaluations are technically difficult. Either modality alone is not a direct measure of the function of the phrenic nerve and diaphragm unit. In this article, the authors present their method for evaluating phrenic nerve function and the resulting diaphragm function. Stimulating the phrenic nerve with transcutaneous stimulation and directly observing the resulting movement of the hemidiaphragm with M-mode ultrasonography provides quantitative data for predicting the success of advancing technologies such as phrenic nerve pacing and diaphragm pacing. Copyright © 2015 Elsevier Inc. All rights reserved.

Peripheral Nerve Regeneration by Secretomes of Stem Cells from Human Exfoliated Deciduous Teeth.

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Sugimura-Wakayama, Yukiko; Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Ogata, Kenichi; Sakaguchi, Kohei; Hibi, Hideharu

2015-11-15

Peripheral nerve regeneration across nerve gaps is often suboptimal, with poor functional recovery. Stem cell transplantation-based regenerative therapy is a promising approach for axon regeneration and functional recovery of peripheral nerve injury; however, the mechanisms remain controversial and unclear. Recent studies suggest that transplanted stem cells promote tissue regeneration through a paracrine mechanism. We investigated the effects of conditioned media derived from stem cells from human exfoliated deciduous teeth (SHED-CM) on peripheral nerve regeneration. In vitro, SHED-CM-treated Schwann cells exhibited significantly increased proliferation, migration, and the expression of neuron-, extracellular matrix (ECM)-, and angiogenesis-related genes. SHED-CM stimulated neuritogenesis of dorsal root ganglia and increased cell viability. Similarly, SHED-CM enhanced tube formation in an angiogenesis assay. In vivo, a 10-mm rat sciatic nerve gap model was bridged by silicon conduits containing SHED-CM or serum-free Dulbecco's modified Eagle's medium. Light and electron microscopy confirmed that the number of myelinated axons and axon-to-fiber ratio (G-ratio) were significantly higher in the SHED-CM group at 12 weeks after nerve transection surgery. The sciatic functional index (SFI) and gastrocnemius (target muscle) wet weight ratio demonstrated functional recovery. Increased compound muscle action potentials and increased SFI in the SHED-CM group suggested sciatic nerve reinnervation of the target muscle and improved functional recovery. We also observed reduced muscle atrophy in the SHED-CM group. Thus, SHEDs may secrete various trophic factors that enhance peripheral nerve regeneration through multiple mechanisms. SHED-CM may therefore provide a novel therapy that creates a more desirable extracellular microenvironment for peripheral nerve regeneration.

Peripheral nerve conduits: technology update

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Arslantunali D

2014-12-01

Full Text Available D Arslantunali,1–3,* T Dursun,1,2,* D Yucel,1,4,5 N Hasirci,1,2,6 V Hasirci,1,2,7 1BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University (METU, Ankara, Turkey; 2Department of Biotechnology, METU, Ankara, Turkey; 3Department of Bioengineering, Gumushane University, Gumushane, Turkey; 4Faculty of Engineering, Department of Medical Engineering, Acibadem University, Istanbul, Turkey; 5School of Medicine, Department of Histology and Embryology, Acibadem University, Istanbul, Turkey; 6Department of Chemistry, Faculty of Arts and Sciences, METU, Ankara, Turkey; 7Department of Biological Sciences, Faculty of Arts and Sciences, METU, Ankara, Turkey *These authors have contributed equally to this work Abstract: Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers and designs (tubular, fibrous, and matrix type are being presented. Keywords: peripheral nerve injury, natural biomaterials, synthetic biomaterials

The challenges and beauty of peripheral nerve regrowth.

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Zochodne, Douglas W

2012-03-01

This review provides an overview of selected aspects of peripheral nerve regeneration and potential avenues to explore therapeutically. The overall coordinated and orchestrated pattern of recovery from peripheral nerve injury has a beauty of execution and progress that rivals all other forms of neurobiology. It involves changes at the level of the perikaryon, coordination with important peripheral glial partners, the Schwann cells, a controlled inflammatory response, and growth that overcomes surprising intrinsic roadblocks. Both regenerative axon growth and collateral sprouting encompass fascinating aspects of this story. Better understanding of peripheral nerve regeneration may also lead to enhanced central nervous system recovery. © 2012 Peripheral Nerve Society.

3D printing strategies for peripheral nerve regeneration.

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Petcu, Eugen B; Midha, Rajiv; McColl, Erin; Popa-Wagner, Aurel; Chirila, Traian V; Dalton, Paul D

2018-03-23

After many decades of biomaterials research for peripheral nerve regeneration, a clinical product (the nerve guide), is emerging as a proven alternative for relatively short injury gaps. This review identifies aspects where 3D printing can assist in improving long-distance nerve guide regeneration strategies. These include (1) 3D printing of the customizable nerve guides, (2) fabrication of scaffolds that fill nerve guides, (3) 3D bioprinting of cells within a matrix/bioink into the nerve guide lumen and the (4) establishment of growth factor gradients along the length a nerve guide. The improving resolution of 3D printing technologies will be an important factor for peripheral nerve regeneration, as fascicular-like guiding structures provide one path to improved nerve guidance. The capability of 3D printing to manufacture complex structures from patient data based on existing medical imaging technologies is an exciting aspect that could eventually be applied to treating peripheral nerve injury. Ultimately, the goal of 3D printing in peripheral nerve regeneration is the automated fabrication, potentially customized for the patient, of structures within the nerve guide that significantly outperform the nerve autograft over large gap injuries.

Sensory adaptation to electrical stimulation of the somatosensory nerves.

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Graczyk, Emily Lauren; Delhaye, Benoit; Schiefer, Matthew A; Bensmaia, Sliman J; Tyler, Dustin J

2018-03-19

Sensory systems adapt their sensitivity to ambient stimulation levels to improve their responsiveness to changes in stimulation. The sense of touch is also subject to adaptation, as evidenced by the desensitization produced by prolonged vibratory stimulation of the skin. Electrical stimulation of nerves elicits tactile sensations that can convey feedback for bionic limbs. In this study, we investigate whether artificial touch is also subject to adaptation, despite the fact that the peripheral mechanotransducers are bypassed. Approach: Using well-established psychophysical paradigms, we characterize the time course and magnitude of sensory adaptation caused by extended electrical stimulation of the residual somatosensory nerves in three human amputees implanted with cuff electrodes. Main results: We find that electrical stimulation of the nerve also induces perceptual adaptation that recovers after cessation of the stimulus. The time course and magnitude of electrically-induced adaptation are equivalent to their mechanically-induced counterparts. Significance: We conclude that, in natural touch, the process of mechanotransduction is not required for adaptation, and artificial touch naturally experiences adaptation-induced adjustments of the dynamic range of sensations. Further, as it does for native hands, adaptation confers to bionic hands enhanced sensitivity to changes in stimulation and thus a more natural sensory experience. . Creative Commons Attribution license.

Engineering a multimodal nerve conduit for repair of injured peripheral nerve

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Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

2013-02-01

Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

Side Effects: Nerve Problems (Peripheral Neuropathy)

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Nerve problems, such as peripheral neuropathy, can be caused by cancer treatment. Learn about signs and symptoms of nerve changes. Find out how to prevent or manage nerve problems during cancer treatment.

Case report of a patient with peripheral facial nerve palsy

OpenAIRE

Rysová, Jana

2013-01-01

Title of bachelor's thesis: Case report of a patient with peripheral facial nerve palsy Summary: Teoretical part of bachelor's thesis contains theoretical foundation of peripheral facial nerve palsy. Practical part of bachelor's thesis contains physiotherapeutic case report of patient with peripheral facial nerve palsy. Key words: peripheral facial nerve palsy, casuistry, rehabilitation

Peripheral Neuropathy and Nerve Compression Syndromes in Burns.

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Strong, Amy L; Agarwal, Shailesh; Cederna, Paul S; Levi, Benjamin

2017-10-01

Peripheral neuropathy and nerve compression syndromes lead to substantial morbidity following burn injury. Patients present with pain, paresthesias, or weakness along a specific nerve distribution or experience generalized peripheral neuropathy. The symptoms manifest at various times from within one week of hospitalization to many months after wound closure. Peripheral neuropathy may be caused by vascular occlusion of vasa nervorum, inflammation, neurotoxin production leading to apoptosis, and direct destruction of nerves from the burn injury. This article discusses the natural history, diagnosis, current treatments, and future directions for potential interventions for peripheral neuropathy and nerve compression syndromes related to burn injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Adult Stem Cell Based Enhancement of Nerve Conduit for Peripheral Nerve Repair

Science.gov (United States)

2016-10-01

accompanied by injuries to peripheral nerves; if not repaired, the trauma can lead to significant dysfunction and disability . While nerves have the ability to...recovery, minimized disability , and increased quality of life for our wounded warriors. 2. KEYWORDS: Stem Cell, Nerve Conduit, Peripheral Nerve...would be a paradigm shift away from ordering X-rays at 10-12 weeks and only ordering a CT scan. It has the potential to change the standard of care

Peripheral nerve regeneration through P(DLLA-epsilon-CL) nerve guides

NARCIS (Netherlands)

Den Dunnen, WFA; Meek, MF; Robinson, PH; Schakernraad, JM

1998-01-01

P(DLLA-epsilon-CL) nerve guides can be used perfectly for short nerve gaps in rats, and are even better than short autologous nerve grafts. The tube dimensions, such as the internal diameter and wall thickness, are very important for the final outcome of peripheral nerve regeneration, as well as the

Percutaneous tibial nerve stimulation vs sacral nerve stimulation for faecal incontinence: a comparative case-matched study.

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Al Asari, S; Meurette, G; Mantoo, S; Kubis, C; Wyart, V; Lehur, P-A

2014-11-01

The study assessed the initial experience with posterior tibial nerve stimulation (PTNS) for faecal incontinence and compared it with sacral nerve stimulation (SNS) performed in a single centre during the same timespan. A retrospective review of a prospectively collected database was conducted at the colorectal unit, University Hospital, Nantes, France, from May 2009 to December 2010. Seventy-eight patients diagnosed with chronic severe faecal incontinence underwent neurostimulation including PTNS in 21 and SNS in 57. The main outcome measures were faecal incontinence (Wexner score) and quality of life (Fecal Incontinence Quality of Life, FIQL) scores in a short-term follow-up. No significant differences were observed in patients' characteristics. Of 57 patients having SNS, 18 (32%) failed peripheral nerve evaluation and 39 (68%) received a permanent implant. Two (5%) developed a wound infection. No adverse effects were recorded in the PTNS group. There was no significant difference in the mean Wexner and FIQL scores between patients having PTNS and SNS at 6 (P = 0.39 and 0.09) and 12 months (P = 0.79 and 0.37). A 50% or more improvement in Wexner score was seen at 6 and 12 months in 47% and 30% of PTNS patients and in 50% and 58% of SNS patients with no significant difference between the groups. Posterior tibial nerve stimulation is a valid method of treating faecal incontinence in the short term when conservative treatment has failed. It is easier, simpler, cheaper and less invasive than SNS with a similar short-term outcome. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

External laryngeal nerve in thyroid surgery: is the nerve stimulator necessary?

Science.gov (United States)

Aina, E N; Hisham, A N

2001-09-01

To find out the incidence and type of external laryngeal nerves during operations on the thyroid, and to assess the role of a nerve stimulator in detecting them. Prospective, non-randomised study. Teaching hospital, Malaysia. 317 patients who had 447 dissections between early January 1998 and late November 1999. Number and type of nerves crossing the cricothyroid space, and the usefulness of the nerve stimulator in finding them. The nerve stimulator was used in 206/447 dissections (46%). 392 external laryngeal nerves were seen (88%), of which 196/206 (95%) were detected with the stimulator. However, without the stimulator 196 nerves were detected out of 241 dissections (81%). The stimulator detected 47 (23%) Type I nerves (nerve > 1 cm from the upper edge of superior pole); 86 (42%) Type IIa nerves (nerve edge of superior pole); and 63 (31%) Type IIb nerves (nerve below upper edge of superior pole). 10 nerves were not detected. When the stimulator was not used the corresponding figures were 32 (13%), 113 (47%), and 51 (21%), and 45 nerves were not seen. If the nerve cannot be found we recommend dissection of capsule close to the medial border of the upper pole of the thyroid to avoid injury to the nerve. Although the use of the nerve stimulator seems desirable, it confers no added advantage in finding the nerve. In the event of uncertainty about whether a structure is the nerve, the stimulator may help to confirm it. However, exposure of the cricothyroid space is most important for good exposure in searching for the external laryngeal nerve.

Low-frequency electrical stimulation induces the proliferation and differentiation of peripheral blood stem cells into Schwann cells.

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Gu, Xudong; Fu, Jianming; Bai, Jing; Zhang, Chengwen; Wang, Jing; Pan, Wenping

2015-02-01

Functional recovery after peripheral nerve injury remains a tough problem at present. Specifically, a type of glial cell exists in peripheral nerves that promotes axonal growth and myelin formation and secretes various active substances, such as neurotrophic factors, extracellular matrix and adherence factors. These substances have important significance for the survival, growth and regeneration of nerve fibers. Numerous recent studies have shown that electrical stimulation can increase the number of myelinated nerve fibers. However, whether electrical stimulation acts on neurons or Schwann cells has not been verified in vivo. This study investigates low-frequency electrical stimulation-induced proliferation and differentiation of peripheral blood stem cells into Schwann cells and explores possible mechanisms. Peripheral blood stem cells from Sprague-Dawley rats were primarily cultured. Cells in passage 3 were divided into 4 groups: a low-frequency electrical stimulation group (20 Hz, 100 μs, 3 V), a low-frequency electrical stimulation+PD98059 (blocking the extracellular signal-regulated kinase [ERK] signaling pathway) group, a PD98059 group and a control group (no treatment). After induction, the cells were characterized. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide assay was employed to measure the absorbance values at 570 nm in the 4 groups. A Western blot assay was used to detect the expression of cyclin D1 and cyclin-dependent kinase 4 (CDK4) in each group. No significant difference in cell viability was detected before induction. Peripheral blood stem cells from the 4 groups differentiated into Schwann cells. Phosphorylated ERK 1/2, cyclin D1 and CDK4 protein levels were highest in the low-frequency electrical stimulation group and lowest in the ERK blockage group. Phosphorylated ERK 1/2, cyclin D1 and CDK4 protein levels in the low-frequency electrical stimulation+ERK blockage group were lower than those in the low-frequency electrical

An artificial arm/hand system with a haptic sensory function using electric stimulation of peripheral sensory nerve fibers.

Science.gov (United States)

Mabuchi, Kunihiko

2013-01-01

We are currently developing an artificial arm/hand system which is capable of sensing stimuli and then transferring these stimuli to users as somatic sensations. Presently, we are evoking the virtual somatic sensations by electrically stimulating a sensory nerve fiber which innervates a single mechanoreceptor unit at the target area; this is done using a tungsten microelectrode that was percutaneously inserted into the use's peripheral nerve (a microstimulation method). The artificial arm/hand system is composed of a robot hand equipped with a pressure sensor system on its fingers. The sensor system detects mechanical stimuli, which are transferred to the user by means of the microstimulation method so that the user experiences the stimuli as the corresponding somatic sensations. In trials, the system worked satisfactorily and there was a good correlation between the pressure applied to the pressure sensors on the robot fingers and the subjective intensities of the evoked pressure sensations.

Peripheral facial nerve dysfunction: CT evaluation

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Disbro, M.A.; Harnsberger, H.R.; Osborn, A.G.

1985-06-01

Peripheral facial nerve dysfunction may have a clinically apparent or occult cause. The authors reviewed the clinical and radiographic records of 36 patients with peripheral facial nerve dysfunction to obtain information on the location of the suspected lesion and the number, sequence, and type of radiographic evaluations performed. Inadequate clinical evaluations before computed tomography (CT) was done and unnecessary CT examinations were also noted. They have suggested a practical clinical and radiographic scheme to evaluate progressive peripheral facial dysfunction with no apparent cause. If this scheme is applied, unnecessary radiologic tests and delays in diagnosis and treatment may be avoided.

Changes in the frequency of swallowing during electrical stimulation of superior laryngeal nerve in rats.

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Tsuji, Kojun; Tsujimura, Takanori; Magara, Jin; Sakai, Shogo; Nakamura, Yuki; Inoue, Makoto

2015-02-01

The aim of the present study was to investigate the adaptation of the swallowing reflex in terms of reduced swallowing reflex initiation following continuous superior laryngeal nerve stimulation. Forty-four male Sprague Dawley rats were anesthetized with urethane. To identify swallowing, electromyographic activity of the left mylohyoid and thyrohyoid muscles was recorded. To evoke the swallowing response, the superior laryngeal nerve (SLN), recurrent laryngeal nerve, or cortical swallowing area was electrically stimulated. Repetitive swallowing evoked by continuous SLN stimulation was gradually reduced, and this reduction was dependent on the resting time duration between stimulations. Prior SLN stimulation also suppressed subsequent swallowing initiation. The reduction in evoked swallows induced by recurrent laryngeal nerve or cortical swallowing area stimulation was less than that following superior laryngeal nerve stimulation. Decerebration had no effect on the reduction in evoked swallows. Prior subthreshold stimulation reduced subsequent initiation of swallowing, suggesting that there was no relationship between swallowing movement evoked by prior stimulation and the subsequent reduction in swallowing initiation. Overall, these data suggest that reduced sensory afferent nerve firing and/or trans-synaptic responses, as well as part of the brainstem central pattern generator, are involved in adaptation of the swallowing reflex following continuous stimulation of swallow-inducing peripheral nerves and cortical areas. Copyright © 2014 Elsevier Inc. All rights reserved.

Use of superficial peroneal nerve graft for treating peripheral nerve injuries

Directory of Open Access Journals (Sweden)

Samuel Ribak

2016-02-01

Full Text Available ABSTRACT OBJECTIVE: To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. METHODS: This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve was identified. The proximal limit of the sensitive branch was found at this point. RESULTS: The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. CONCLUSIONS: Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources.

Remote-Activated Electrical Stimulation via Piezoelectric Scaffold System for Functional Peripheral and Central Nerve Regeneration

OpenAIRE

Low, Karen Gail

2017-01-01

A lack of therapeutic technologies that enable electrically stimulating nervous tissues in a facile and clinically relevant manner has partly hindered the advancement in treating nerve injuries for full functional recovery. Currently, the gold standard for nerve repair is autologous nerve grafting. However, this method has several disadvantages, such as necessity for multiple surgeries, creation of functionally impaired region where graft was taken from, disproportion of graft to nerve tissue...

Electrical stimulation enhanced remyelination of injured sciatic nerves by increasing neurotrophins.

Science.gov (United States)

Wan, L D; Xia, R; Ding, W L

2010-09-01

Previous studies have demonstrated that electrical stimulation (ES) enhances axonal regeneration following central and peripheral nerve injury. However, the effect of ES on peripheral remyelination after nerve damage has been investigated less, and the mechanism underlying its action remains unclear. In the present study, neuron/Schwann cell (SC) co-cultures in vitro and crush-injured sciatic nerves in rats were subjected to 1 h of continuous ES (20 Hz, 100 micros, 3 V). Electron microscopy and nerve morphometry were performed to investigate the extent of regenerated nerve myelination. The expression profiles of P0, Par-3 and brain-derived neurotrophic factor (BDNF) in vitro and in vivo were examined by western blotting. We reported that 20 Hz ES increased the number of regenerated and myelinated axons at 4 and 8 weeks after injury. P0 level in the ES-treated groups, as well as myelin sheath thickness, were enhanced compared with the controls. The earlier peak Par-3 in the ES-treated groups indicated earlier initiation of SC myelination. Moreover, the similar results were achieved in the cell co-culture. Additionally, brief ES significantly elevated BDNF expression in co-cultured cells and nerve tissues. In conclusion, ES of the site of nerve injury potentiates axonal regrowth and myelin maturation during peripheral nerve regeneration. Further, the therapeutic actions of ES on myelination that is mediated via enhanced BDNF signals, which driving the promyelination effect on SCs at the onset of myelination. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Long-Term Reduction of Sacroiliac Joint Pain With Peripheral Nerve Stimulation.

Science.gov (United States)

Guentchev, Marin; Preuss, Christian; Rink, Rainer; Peter, Levente; Sailer, Martin H M; Tuettenberg, Jochen

2017-10-01

We recently demonstrated that 86% of the patients treated with peripheral nerve stimulation (PNS) for therapy-refractory sacroiliac joint (SIJ) pain were satisfied with the result after 1 year of treatment. To investigate the long-term (up to 4 years) response rate of this novel treatment. Sixteen consecutive patients with therapy-refractory SIJ pain were treated with PNS and followed for 4 years in 3 patients, 3 years in 6 patients, and 2 years in 1 patient. Quality of life, pain, and patient satisfaction were assessed using the Oswestry Disability Index 2.0, Visual Analog Scale (VAS), and International Patient Satisfaction Index. Patients reported a pain reduction from 8.8 to 1.6 (VAS) at 1 year ( P < .001), and 13 of 14 patients (92.9%) rated the therapy as effective (International Patient Satisfaction Index score ≤ 2). At 2 years, average pain score was 1.9 ( P < .001), and 9 of 10 patients (90.0%) considered the treatment a success. At 3 years, 8 of 9 patients (88.9%) were satisfied with the treatment results, reporting an average VAS of 2.0 ( P < .005). At 4 years, 2 of 3 patients were satisfied with the treatment results. We have shown for the first time that PNS is a successful long-term therapy for SIJ pain. Copyright © 2017 by the Congress of Neurological Surgeons

Electrical Stimulation to Enhance Axon Regeneration After Peripheral Nerve Injuries in Animal Models and Humans

OpenAIRE

Gordon, Tessa

2016-01-01

Injured peripheral nerves regenerate their lost axons but functional recovery in humans is frequently disappointing. This is so particularly when injuries require regeneration over long distances and/or over long time periods. Fat replacement of chronically denervated muscles, a commonly accepted explanation, does not account for poor functional recovery. Rather, the basis for the poor nerve regeneration is the transient expression of growth-associated genes that accounts for declining regene...

Malignant Peripheral Nerve Sheath Tumour of the Maxilla

Directory of Open Access Journals (Sweden)

Puja Sahai

2014-01-01

Full Text Available A 38-year-old man was diagnosed with malignant peripheral nerve sheath tumour of the maxilla. He was treated with total maxillectomy. Histopathological examination of the resected specimen revealed a close resection margin. The tumour was of high grade with an MIB-1 labelling index of almost 60%. At six weeks following the surgery, he developed local tumour relapse. The patient succumbed to the disease at five months from the time of diagnosis. The present report underlines the locally aggressive nature of malignant peripheral nerve sheath tumour of the maxilla which necessitates an early therapeutic intervention. A complete resection with clear margins is the most important prognostic factor for malignant peripheral nerve sheath tumour in the head and neck region. Adjuvant radiotherapy may be considered to improve the local control. Future research may demarcate the role of targeted therapy for patients with malignant peripheral nerve sheath tumour.

Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis.

Science.gov (United States)

Schiefer, Matthew; Tan, Daniel; Sidek, Steven M; Tyler, Dustin J

2016-02-01

Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject's sense of embodiment with a survey and his self-confidence. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

Tibial nerve stimulation for overactive bladder syndrome unresponsive to medical therapy.

Science.gov (United States)

Ridout, A E; Yoong, W

2010-02-01

Overactive bladder syndrome is defined as a symptom syndrome which includes urinary urgency, with or without urge incontinence, usually accompanied by frequency (>8 micturitions/24 h) and nocturia. Conservative treatment usually comprises behavioural techniques, bladder retraining, pelvic floor re-education and pharmacotherapy but up to 30% of patients will remain refractory to treatment. Although second-line treatment options such as sacral nerve stimulation and intravesical botulinum A injections are valuable additions to the therapeutic arsenal, they are relatively invasive and can have serious side-effects. Inhibition of detrusor activity by peripheral neuromodulation of the posterior tibial nerve was first described in 1983, with recent authors further confirming a 60-80% positive response rate. This review was undertaken to examine published literature on percutaneous tibial nerve stimulation and to discuss outcome measures, maintenance therapy and prognostic factors of this technique.

Reference values and clinical application of magnetic peripheral nerve stimulation in cats

NARCIS (Netherlands)

Van Soens, Iris; Struys, Michel M. R. F.; Bhatti, Sofie F. M.; Van Ham, Luc M. L.

Magnetic stimulation of radial (RN) and sciatic (SN) nerves was performed bilaterally in 40 healthy cats. Reference values for onset latency and peak-to-peak amplitude of magnetic motor evoked potentials (MMEPs) were obtained and compared with values of electric motor evoked potentials (EMEPs) in

[Postoperative rehabilitation in patients with peripheral nerve lesions].

Science.gov (United States)

Petronić, I; Marsavelski, A; Nikolić, G; Cirović, D

2003-01-01

Injuries of extremities can be followed by various neuromuscular complications. Injury of peripheral nerves directly depended on the topographic localization of injury (fractures, cuts, contusions). The neuromuscular complications were diagnosed and under follow-up, based on clinical, x-ray, neurologic and neurophysiological findings. The timing of physical treatment and assessment of the necessary neurosurgical intervention depended on the obtained findings. After surgeries, we continued to apply physical treatment and rehabilitation. The aim of the paper was to assess the significance of proper timing for surgery and adequate postoperative rehabilitation, as well as treatment results, depending on the extent of peripheral nerve injury. Based on the study condocted in the period from 2000-2002, most surgeries were done on the ulnar nerve (4 pts), median nerve (4 pts), radial nerve (3 pts), peroneal nerve (2 pts) and plexus brachialis (3 pts). Paresis and peripheral nerve paralysis, associated with sensibility disorders, predominated in clinical features. In most patients surgery was done during the first 3-6 months after injury. In early postoperative Postoperative rehabilitation in patients with peripherial treatment positioning of extremities with electrotherapy were most often used in early postoperative treatment, Bioptron and dosed kinesitherapy. Depending on the neurophysiological findings, in later treatment stage we included electrostimulation, thermotherapy, kinesitherapy and working therapy, with the necessary application of static and dynamic orthroses. Study results showed that the success of treatment depended on the extent of injury, i.e. whether suture of liberalization of the nerve had been done, on the adequate timing of surgery, as well as on the adequate timing and application of physical therapy and rehabilitation. More rapid and complete functional recovery was achieved if the interval between injury and surgery was shorter, as well as

In vitro electrophoresis and in vivo electrophysiology of peripheral nerve using DC field stimulation

DEFF Research Database (Denmark)

Madison, Roger D.; Robinson, Grant A.; Krarup, Christian

2014-01-01

BACKGROUND: Given the movement of molecules within tissue that occurs naturally by endogenous electric fields, we examined the possibility of using a low-voltage DC field to move charged substances in rodent peripheral nerve in vitro. NEW METHOD: Labeled sugar- and protein-based markers were appl...

Peripheral nerve hyperexcitability with preterminal nerve and neuromuscular junction remodeling is a hallmark of Schwartz-Jampel syndrome.

Science.gov (United States)

Bauché, Stéphanie; Boerio, Delphine; Davoine, Claire-Sophie; Bernard, Véronique; Stum, Morgane; Bureau, Cécile; Fardeau, Michel; Romero, Norma Beatriz; Fontaine, Bertrand; Koenig, Jeanine; Hantaï, Daniel; Gueguen, Antoine; Fournier, Emmanuel; Eymard, Bruno; Nicole, Sophie

2013-12-01

Schwartz-Jampel syndrome (SJS) is a recessive disorder with muscle hyperactivity that results from hypomorphic mutations in the perlecan gene, a basement membrane proteoglycan. Analyses done on a mouse model have suggested that SJS is a congenital form of distal peripheral nerve hyperexcitability resulting from synaptic acetylcholinesterase deficiency, nerve terminal instability with preterminal amyelination, and subtle peripheral nerve changes. We investigated one adult patient with SJS to study this statement in humans. Perlecan deficiency due to hypomorphic mutations was observed in the patient biological samples. Electroneuromyography showed normal nerve conduction, neuromuscular transmission, and compound nerve action potentials while multiple measures of peripheral nerve excitability along the nerve trunk did not detect changes. Needle electromyography detected complex repetitive discharges without any evidence for neuromuscular transmission failure. The study of muscle biopsies containing neuromuscular junctions showed well-formed post-synaptic element, synaptic acetylcholinesterase deficiency, denervation of synaptic gutters with reinnervation by terminal sprouting, and long nonmyelinated preterminal nerve segments. These data support the notion of peripheral nerve hyperexcitability in SJS, which would originate distally from synergistic actions of peripheral nerve and neuromuscular junction changes as a result of perlecan deficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

The potential of electrical stimulation to promote functional recovery after peripheral nerve injury--comparisons between rats and humans.

Science.gov (United States)

Gordon, T; Brushart, T M; Amirjani, N; Chan, K M

2007-01-01

The declining capacity for injured peripheral nerves to regenerate their axons with time and distance is accounted for, at least in part, by the chronic axotomy of the neurons and Schwann cell denervation prior to target reinnervation. A largely unrecognized site of delay is the surgical suture site where, in rats, 4 weeks is required for all neurons to regenerate their axons across the site. Low frequency stimulation for just 1 h after surgery accelerates this axon crossing in association with upregulation of neurotrophic factors in the neurons. We translated these findings to human patients by examining the number of reinnervated motor units in the median nerve-innervated thenar muscles before and after carpel tunnel release surgery in a randomized controlled trial. Motor unit number estimates (MUNE) in patients with moderate and severe carpal tunnel syndrome were significantly lower than normal. This number increased significantly by 6-8 months after surgery and reached normal values by 12 months in contrast to a non-significant increase in the control unstimulated group. Tests including the Purdue Pegboard Test verified the more rapid functional recovery after stimulation. The data indicate a feasible strategy to promote axonal regeneration in humans that has the potential to improve functional outcomes, especially in combination with strategies to sustain the regenerative capacity of neurons and the support of Schwann cells over distance and time.

Sonographic identification of peripheral nerves in the forearm

Directory of Open Access Journals (Sweden)

Saundra A Jackson

2016-01-01

Full Text Available Background: With the growing utilization of ultrasonography in emergency medicine combined with the concern over adequate pain management in the emergency department (ED, ultrasound guidance for peripheral nerve blockade in ED is an area of increasing interest. The medical literature has multiple reports supporting the use of ultrasound guidance in peripheral nerve blocks. However, to perform a peripheral nerve block, one must first be able to reliably identify the specific nerve before the procedure. Objective: The primary purpose of this study is to describe the number of supervised peripheral nerve examinations that are necessary for an emergency medicine physician to gain proficiency in accurately locating and identifying the median, radial, and ulnar nerves of the forearm via ultrasound. Methods: The proficiency outcome was defined as the number of attempts before a resident is able to correctly locate and identify the nerves on ten consecutive examinations. Didactic education was provided via a 1 h lecture on forearm anatomy, sonographic technique, and identification of the nerves. Participants also received two supervised hands-on examinations for each nerve. Count data are summarized using percentages or medians and range. Random effects negative binomial regression was used for modeling panel count data. Results: Complete data for the number of attempts, gender, and postgraduate year (PGY training year were available for 38 residents. Nineteen males and 19 females performed examinations. The median PGY year in practice was 3 (range 1-3, with 10 (27% in year 1, 8 (22% in year 2, and 19 (51% in year 3 or beyond. The median number (range of required supervised attempts for radial, median, and ulnar nerves was 1 (0-12, 0 (0-10, and 0 (0-17, respectively. Conclusion: We can conclude that the maximum number of supervised attempts to achieve accurate nerve identification was 17 (ulnar, 12 (radial, and 10 (median in our study. The only

Nerve autografts and tissue-engineered materials for the repair of peripheral nerve injuries: a 5-year bibliometric analysis

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Yuan Gao

2015-01-01

Full Text Available With advances in biomedical methods, tissue-engineered materials have developed rapidly as an alternative to nerve autografts for the repair of peripheral nerve injuries. However, the materials selected for use in the repair of peripheral nerve injuries, in particular multiple injuries and large-gap defects, must be chosen carefully. Various methods and materials for protecting the healthy tissue and repairing peripheral nerve injuries have been described, and each method or material has advantages and disadvantages. Recently, a large amount of research has been focused on tissue-engineered materials for the repair of peripheral nerve injuries. Using the keywords "pe-ripheral nerve injury", "autotransplant", "nerve graft", and "biomaterial", we retrieved publications using tissue-engineered materials for the repair of peripheral nerve injuries appearing in the Web of Science from 2010 to 2014. The country with the most total publications was the USA. The institutions that were the most productive in this field include Hannover Medical School (Germany, Washington University (USA, and Nantong University (China. The total number of publications using tissue-engineered materials for the repair of peripheral nerve injuries grad-ually increased over time, as did the number of Chinese publications, suggesting that China has made many scientific contributions to this field of research.

Progress of nerve bridges in the treatment of peripheral nerve disruptions

OpenAIRE

Ao,Qiang

2016-01-01

Qiang Ao Department of Tissue Engineering, School of Fundamental Science, China Medical University, Shenyang, Liaoning, Peoples’ Republic of China Abstract: Clinical repair of a nerve defect is one of the most challenging surgical problems. Autologous nerve grafting remains the gold standard treatment in addressing peripheral nerve injuries that cannot be bridged by direct epineural suturing. However, the autologous nerve graft is not readily available, and the process of harvesting...

New sonographic measures of peripheral nerves: a tool for the diagnosis of peripheral nerve involvement in leprosy

Directory of Open Access Journals (Sweden)

Marco Andrey Cipriani Frade

2013-05-01

Full Text Available To evaluate ultrasonographic (US cross-sectional areas (CSAs of peripheral nerves, indexes of the differences between CSAs at the same point (∆CSAs and between tunnel (T and pre-tunnel (PT ulnar CSAs (∆TPTs in leprosy patients (LPs and healthy volunteers (HVs. Seventy-seven LPs and 49 HVs underwent bilateral US at PT and T ulnar points, as well as along the median (M and common fibular (CF nerves, to calculate the CSAs, ∆CSAs and ∆TPTs. The CSA values in HVs were lower than those in LPs (p 80% and ∆TPT had the highest specificity (> 90%. New sonographic peripheral nerve measurements (∆CSAs and ∆TPT provide an important methodological improvement in the detection of leprosy neuropathy.

Molybdenum coated SU-8 microneedle electrodes for transcutaneous electrical nerve stimulation.

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Soltanzadeh, Ramin; Afsharipour, Elnaz; Shafai, Cyrus; Anssari, Neda; Mansouri, Behzad; Moussavi, Zahra

2017-11-21

Electrophysiological devices are connected to the body through electrodes. In some applications, such as nerve stimulation, it is needed to minimally pierce the skin and reach the underneath layers to bypass the impedance of the first layer called stratum corneum. In this study, we have designed and fabricated surface microneedle electrodes for applications such as electrical peripheral nerve stimulation. We used molybdenum for microneedle fabrication, which is a biocompatible metal; it was used for the conductive layer of the needle array. To evaluate the performance of the fabricated electrodes, they were compared with the conventional surface electrodes in nerve conduction velocity experiment. The recorded signals showed a much lower contact resistance and higher bandwidth in low frequencies for the fabricated microneedle electrodes compared to those of the conventional electrodes. These results indicate the electrode-tissue interface capacitance and charge transfer resistance have been increased in our designed electrodes, while the contact resistance decreased. These changes will lead to less harmful Faradaic current passing through the tissue during stimulation in different frequencies. We also compared the designed microneedle electrodes with conventional ones by a 3-dimensional finite element simulation. The results demonstrated that the current density in the deep layers of the skin and the directivity toward a target nerve for microneedle electrodes were much more than those for the conventional ones. Therefore, the designed electrodes are much more efficient than the conventional electrodes for superficial transcutaneous nerve stimulation purposes.

Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis

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Schiefer, Matthew; Tan, Daniel; Sidek, Steven M.; Tyler, Dustin J.

2016-02-01

Objective. Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Approach. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject’s sense of embodiment with a survey and his self-confidence. Main results. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Significance. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

Intravenous Transplantation of Mesenchymal Stromal Cells to Enhance Peripheral Nerve Regeneration

Directory of Open Access Journals (Sweden)

Stella M. Matthes

2013-01-01

Full Text Available Peripheral nerve injury is a common and devastating complication after trauma and can cause irreversible impairment or even complete functional loss of the affected limb. While peripheral nerve repair results in some axonal regeneration and functional recovery, the clinical outcome is not optimal and research continues to optimize functional recovery after nerve repair. Cell transplantation approaches are being used experimentally to enhance regeneration. Intravenous infusion of mesenchymal stromal cells (MSCs into spinal cord injury and stroke was shown to improve functional outcome. However, the repair potential of intravenously transplanted MSCs in peripheral nerve injury has not been addressed yet. Here we describe the impact of intravenously infused MSCs on functional outcome in a peripheral nerve injury model. Rat sciatic nerves were transected followed, by intravenous MSCs transplantation. Footprint analysis was carried out and 21 days after transplantation, the nerves were removed for histology. Labelled MSCs were found in the sciatic nerve lesion site after intravenous injection and regeneration was improved. Intravenously infused MSCs after acute peripheral nerve target the lesion site and survive within the nerve and the MSC treated group showed greater functional improvement. The results of study suggest that nerve repair with cell transplantation could lead to greater functional outcome.

An anatomical study of porcine peripheral nerve and its potential use in nerve tissue engineering

Science.gov (United States)

Zilic, Leyla; Garner, Philippa E; Yu, Tong; Roman, Sabiniano; Haycock, John W; Wilshaw, Stacy-Paul

2015-01-01

Current nerve tissue engineering applications are adopting xenogeneic nerve tissue as potential nerve grafts to help aid nerve regeneration. However, there is little literature that describes the exact location, anatomy and physiology of these nerves to highlight their potential as a donor graft. The aim of this study was to identify and characterise the structural and extracellular matrix (ECM) components of porcine peripheral nerves in the hind leg. Methods included the dissection of porcine nerves, localisation, characterisation and quantification of the ECM components and identification of nerve cells. Results showed a noticeable variance between porcine and rat nerve (a commonly studied species) in terms of fascicle number. The study also revealed that when porcine peripheral nerves branch, a decrease in fascicle number and size was evident. Porcine ECM and nerve fascicles were found to be predominately comprised of collagen together with glycosaminoglycans, laminin and fibronectin. Immunolabelling for nerve growth factor receptor p75 also revealed the localisation of Schwann cells around and inside the fascicles. In conclusion, it is shown that porcine peripheral nerves possess a microstructure similar to that found in rat, and is not dissimilar to human. This finding could extend to the suggestion that due to the similarities in anatomy to human nerve, porcine nerves may have utility as a nerve graft providing guidance and support to regenerating axons. PMID:26200940

Chapter 24: Electrical stimulation for improving nerve regeneration: where do we stand?

Science.gov (United States)

Gordon, Tessa; Sulaiman, Olewale A R; Ladak, Adil

2009-01-01

While injured neurons regenerate their axons in the peripheral nervous system, it is well recognized that functional recovery is frequently poor. Animal experiments in which injured motoneurons remain without peripheral targets (chronic axotomy) and Schwann cells in distal nerve stumps remain without innervation (chronic denervation) revealed that it is the duration of chronic axotomy and Schwann cell denervation that accounts for this poor functional recovery and not irreversible muscle atrophy that has been so commonly thought to be the reason. More recently, we demonstrated that axon outgrowth across lesion sites is a major contributing factor to the long delays incurred between the injury and the reinnervation of denervated targets. In the rat, a period of 1 month transpires before all motoneurons regenerate their axons across a lesion site. We have developed a technique of 1 h low-frequency electrical stimulation (ES) of the proximal nerve stump just after surgical repair of a transected peripheral nerve that greatly accelerates axon outgrowth. This technique has been applied in patients after carpal tunnel release surgery where the ES promoted the regeneration of all median nerves to reinnervate thenar muscles within 6-8 months, which contrasted with failure of any injured nerves to reinnervate muscles in the same time frame without ES. These findings are very promising such that the ES method could become a clinically viable tool for accelerating axon regeneration and muscle reinnervation.

Magnetoneurographic evaluation of peripheral nerve regeneration

NARCIS (Netherlands)

P.D.L. Kuypers (Paul)

1998-01-01

textabstractWhen a peripheral nerve is reconstructed after it has been damaged. it is important to assess, in an early stage, whether the nerve is regenerating across the lesion. However, at present for this purpose an adequate method is not available. In this study short term changes in the

Challenges associated with nerve conduction block using kilohertz electrical stimulation

Science.gov (United States)

Patel, Yogi A.; Butera, Robert J.

2018-06-01

Neuromodulation therapies, which electrically stimulate parts of the nervous system, have traditionally attempted to activate neurons or axons to restore function or alleviate disease symptoms. In stark contrast to this approach is inhibiting neural activity to relieve disease symptoms and/or restore homeostasis. One potential approach is kilohertz electrical stimulation (KES) of peripheral nerves—which enables a rapid, reversible, and localized block of conduction. This review highlights the existing scientific and clinical utility of KES and discusses the technical and physiological challenges that must be addressed for successful translation of KES nerve conduction block therapies.

Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

Science.gov (United States)

Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

2011-01-01

Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

High resolution ultrasonography of the tibial nerve in diabetic peripheral neuropathy.

Science.gov (United States)

Singh, Kunwarpal; Gupta, Kamlesh; Kaur, Sukhdeep

2017-12-01

High-resolution ultrasonography of the tibial nerve is a fast and non invasive tool for diagnosis of diabetic peripheral neuropathy. Our study was aimed at finding out the correlation of the cross sectional area and maximum thickness of nerve fascicles of the tibial nerve with the presence and severity of diabetic peripheral neuropathy. 75 patients with type 2 diabetes mellitus clinically diagnosed with diabetic peripheral neuropathy were analysed, and the severity of neuropathy was determined using the Toronto Clinical Neuropathy Score. 58 diabetic patients with no clinical suspicion of diabetic peripheral neuropathy and 75 healthy non-diabetic subjects were taken as controls. The cross sectional area and maximum thickness of nerve fascicles of the tibial nerves were calculated 3 cm cranial to the medial malleolus in both lower limbs. The mean cross sectional area (22.63 +/- 2.66 mm 2 ) and maximum thickness of nerve fascicles (0.70 mm) of the tibial nerves in patients with diabetic peripheral neuropathy compared with both control groups was significantly larger, and statistically significant correlation was found with the Toronto Clinical Neuropathy Score ( p peripheral neuropathy had a larger mean cross sectional area (14.40 +/- 1.72 mm 2 ) and maximum thickness of nerve fascicles of the tibial nerve (0.40 mm) than healthy non-diabetic subjects (12.42 +/- 1.01 mm 2 and 0.30 mm respectively). The cross sectional area and maximum thickness of nerve fascicles of the tibial nerve is larger in diabetic patients with or without peripheral neuropathy than in healthy control subjects, and ultrasonography can be used as a good screening tool in these patients.

End-to-side nerve suture – a technique to repair peripheral nerve ...

African Journals Online (AJOL)

Lateral sprouting from an intact nerve into an attached nerve does occur, and functional recovery (sensory and motor) has been demonstrated. We have demonstrated conclusively that ETSNS in the human is a viable option in treating peripheral nerve injuries, including injuries to the brachial plexus. Among the many ...

Role of connexin 32 hemichannels in the release of ATP from peripheral nerves.

Science.gov (United States)

Nualart-Marti, Anna; del Molino, Ezequiel Mas; Grandes, Xènia; Bahima, Laia; Martin-Satué, Mireia; Puchal, Rafel; Fasciani, Ilaria; González-Nieto, Daniel; Ziganshin, Bulat; Llobet, Artur; Barrio, Luis C; Solsona, Carles

2013-12-01

Extracellular purines elicit strong signals in the nervous system. Adenosine-5'-triphosphate (ATP) does not spontaneously cross the plasma membrane, and nervous cells secrete ATP by exocytosis or through plasma membrane proteins such as connexin hemichannels. Using a combination of imaging, luminescence and electrophysiological techniques, we explored the possibility that Connexin 32 (Cx32), expressed in Schwann cells (SCs) myelinating the peripheral nervous system could be an important source of ATP in peripheral nerves. We triggered the release of ATP in vivo from mice sciatic nerves by electrical stimulation and from cultured SCs by high extracellular potassium concentration-evoked depolarization. No ATP was detected in the extracellular media after treatment of the sciatic nerve with Octanol or Carbenoxolone, and ATP release was significantly inhibited after silencing Cx32 from SCs cultures. We investigated the permeability of Cx32 to ATP by expressing Cx32 hemichannels in Xenopus laevis oocytes. We found that ATP release is coupled to the inward tail current generated after the activation of Cx32 hemichannels by depolarization pulses, and it is sensitive to low extracellular calcium concentrations. Moreover, we found altered ATP release in mutated Cx32 hemichannels related to the X-linked form of Charcot-Marie-Tooth disease, suggesting that purinergic-mediated signaling in peripheral nerves could underlie the physiopathology of this neuropathy. Copyright © 2013 Wiley Periodicals, Inc.

Tonic aortic depressor nerve stimulation does not impede baroreflex dynamic characteristics concomitantly mediated by the stimulated nerve.

Science.gov (United States)

Kawada, Toru; Turner, Michael J; Shimizu, Shuji; Kamiya, Atsunori; Shishido, Toshiaki; Sugimachi, Masaru

2018-03-01

Although electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) is being explored as a device therapy for resistant hypertension, possible effects on baroreflex dynamic characteristics of interaction between electrical stimulation and pressure inputs are not fully elucidated. To examine whether the electrical stimulation of the baroreceptor afferent nerve impedes normal short-term arterial pressure (AP) regulation mediated by the stimulated nerve, we electrically stimulated the right aortic depressor nerve (ADN) while estimating the baroreflex dynamic characteristics by imposing pressure inputs to the isolated baroreceptor region of the right ADN in nine anesthetized rats. A Gaussian white noise signal with a mean of 120 mmHg and standard deviation of 20 mmHg was used for the pressure perturbation. A tonic ADN stimulation (2 or 5 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (367.0 ± 70.9 vs. 247.3 ± 47.2 arbitrary units, P ADN stimulation did not affect the slope of dynamic gain in the neural arc transfer function from pressure perturbation to sympathetic nerve activity (16.9 ± 1.0 vs. 14.7 ± 1.6 dB/decade, not significant). These results indicate that electrical stimulation of the baroreceptor afferent nerve does not significantly impede the dynamic characteristics of the arterial baroreflex concomitantly mediated by the stimulated nerve. Short-term AP regulation by the arterial baroreflex may be preserved during the baroreflex activation therapy.

Peripheral nerve field stimulation for chronic neuropathic pain: a single institution experience.

Science.gov (United States)

D'Ammando, A; Messina, G; Franzini, A; Dones, I

2016-04-01

Peripheral nerve field stimulation (PNFS) is a novel neurosurgical procedure consisting of implantation of subcutaneous leads in specific painful areas in different types of painful, drug-resistant syndromes. The objective of this study was to evaluate the efficacy of PNFS in several patients affected by different chronic neuropathic pain syndromes, along with its risks, limits and possible correlation between the results achieved and the patients' main symptoms. Twenty-two patients affected by different types of chronic neuropathic pain were submitted to PNFS at the Department of Neurosurgery of the Istituto Neurologico "C. Besta" in Milan between July 2009 and July 2013. The visual analog scale (VAS) and variations in the use of analgesic drugs, along with complications, were considered to assess results. In 59 % of our patients, an average pain reduction of 5.50 points on the visual analog scale was observed (average pre-implant score 8.86 and average post-implant score 3.36). These patients reduced their analgesic drug use after PNFS. We observed no early or long-term complications after our last follow-up evaluation. PNFS can be considered an effective and safe option to treat carefully selected, drug-resistant and chronic neuropathic pain patients; the reversibility of the procedure and its lack, at least in our hands, of long-term complications may contribute to wider use of this procedure.

Scaffolds for peripheral nerve repair and reconstruction.

Science.gov (United States)

Yi, Sheng; Xu, Lai; Gu, Xiaosong

2018-06-02

Trauma-associated peripheral nerve defect is a widespread clinical problem. Autologous nerve grafting, the current gold standard technique for the treatment of peripheral nerve injury, has many internal disadvantages. Emerging studies showed that tissue engineered nerve graft is an effective substitute to autologous nerves. Tissue engineered nerve graft is generally composed of neural scaffolds and incorporating cells and molecules. A variety of biomaterials have been used to construct neural scaffolds, the main component of tissue engineered nerve graft. Synthetic polymers (e.g. silicone, polyglycolic acid, and poly(lactic-co-glycolic acid)) and natural materials (e.g. chitosan, silk fibroin, and extracellular matrix components) are commonly used along or together to build neural scaffolds. Many other materials, including the extracellular matrix, glass fabrics, ceramics, and metallic materials, have also been used to construct neural scaffolds. These biomaterials are fabricated to create specific structures and surface features. Seeding supporting cells and/or incorporating neurotrophic factors to neural scaffolds further improve restoration effects. Preliminary studies demonstrate that clinical applications of these neural scaffolds achieve satisfactory functional recovery. Therefore, tissue engineered nerve graft provides a good alternative to autologous nerve graft and represents a promising frontier in neural tissue engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

Neurophysiological approach to disorders of peripheral nerve

DEFF Research Database (Denmark)

Crone, Clarissa; Krarup, Christian

2013-01-01

Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves......, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological...

A nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle

NARCIS (Netherlands)

van Bolhuis, A.I.; Holsheimer, J.; Savelsberg, H.H.C.M.

2001-01-01

Electrical stimulation of peripheral nerve results in a motor-unit recruitment order opposite to that attained by natural neural control, i.e. from large, fast-fatiguing to progressively smaller, fatigue-resistant motor-units. Yet animal studies involving physiological exercise protocols of low

The role of exosomes in peripheral nerve regeneration

Directory of Open Access Journals (Sweden)

Rosanna C Ching

2015-01-01

Full Text Available Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment and synthetic conduits, with the latter option being able to be impregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing difficulties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacrifice of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury.

Delayed peripheral nerve repair: methods, including surgical ?cross-bridging? to promote nerve regeneration

OpenAIRE

Gordon, Tessa; Eva, Placheta; Borschel, Gregory H.

2015-01-01

Despite the capacity of Schwann cells to support peripheral nerve regeneration, functional recovery after nerve injuries is frequently poor, especially for proximal injuries that require regenerating axons to grow over long distances to reinnervate distal targets. Nerve transfers, where small fascicles from an adjacent intact nerve are coapted to the nerve stump of a nearby denervated muscle, allow for functional return but at the expense of reduced numbers of innervating nerves. A 1-hour per...

Occipital Nerve Stimulation for the Treatment of Refractory Occipital Neuralgia: A Case Series.

Science.gov (United States)

Keifer, Orion P; Diaz, Ashley; Campbell, Melissa; Bezchlibnyk, Yarema B; Boulis, Nicholas M

2017-09-01

Occipital neuralgia is a chronic pain syndrome characterized by sharp, shooting pains in the distribution of the occipital nerves. Although relatively rare, it associated with extremely debilitating symptoms that drastically affect a patient's quality of life. Furthermore, it is extremely difficult to treat as the symptoms are refractory to traditional treatments, including pharmacologic and procedural interventions. A few previous case studies have established the use of a neurostimulation of the occipital nerves to treat occipital neuralgia. The following expands on that literature by retrospectively reviewing the results of occipital nerve stimulation in a relatively large patient cohort (29 patients). A retrospective review of 29 patients undergoing occipital nerve stimulation for occipital neuralgia from 2012 to 2017 at a single institution with a single neurosurgeon. Of those 29 patients, 5 were repair or replacement of previous systems, 4 did not have benefit from trial stimulation, and 20 saw benefit to their trial stage of stimulation and went on to full implantation. Of those 20 patients, even with a history of failed procedures and pharmacological therapies, there was an overall success rate of 85%. The average preoperative 10-point pain score dropped from 7.4 ± 1.7 to a postoperative score of 2.9 ± 1.7. However, as with any peripheral nerve stimulation procedure, there were complications (4 patients), including infection, hardware erosion, loss of effect, and lead migration, which required revision or system removal. Despite complications, the results suggest, overall, that occipital nerve stimulation is a safe and effective procedure for refractory occipital neuralgia and should be in the neurosurgical repertoire for occipital neuralgia treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

A nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle.

Science.gov (United States)

van Bolhuis, A I; Holsheimer, J; Savelberg, H H

2001-05-30

Electrical stimulation of peripheral nerve results in a motor-unit recruitment order opposite to that attained by natural neural control, i.e. from large, fast-fatiguing to progressively smaller, fatigue-resistant motor-units. Yet animal studies involving physiological exercise protocols of low intensity and long duration require minimal fatigue. The present study sought to apply a nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle. Two pulse generators were used, independently supplying short supramaximal cathodal stimulating pulses (0.5 ms) and long subthreshold cathodal inactivating pulses (1.5 s) to the sciatic nerve. Propagation of action potentials was selectively blocked in nerve fibres of different diameter by adjusting the strength of the inactivating current. A tensile-testing machine was used to gauge isometric muscle force of the plantaris and both heads of the gastrocnemius muscle. The order of motor-unit recruitment was estimated from twitch characteristics, i.e. peak force and relaxation time. The results showed prolonged relaxation at lower twitch peak forces as the intensity of the inactivating current increased, indicating a reduction of the number of large motor-units to force production. It is shown that the nerve stimulation method described is effective in mimicking physiological muscle control.

Increased electrical nerve stimulation threshold of the sciatic nerve in patients with diabetic foot gangrene: a prospective parallel cohort study.

Science.gov (United States)

Keyl, Cornelius; Held, Tanja; Albiez, Georg; Schmack, Astrid; Wiesenack, Christoph

2013-07-01

Peripheral neuropathy may affect nerve conduction in patients with diabetes mellitus. This study was designed to test the hypothesis that the electrical stimulation threshold for a motor response of the sciatic nerve is increased in patients suffering from diabetic foot gangrene compared to non-diabetic patients. Prospective non-randomised trial with two parallel groups. Two university-affiliated hospitals. Patients scheduled for surgical treatment of diabetic foot gangrene (n = 30) and non-diabetic patients (n = 30) displaying no risk factors for neuropathy undergoing orthopaedic foot or ankle surgery. The minimum current intensity required to elicit a typical motor response (dorsiflexion or eversion of the foot) at a pulse width of 0.1 ms and a stimulation frequency of 1 Hz when the needle tip was positioned under ultrasound control directly adjacent to the peroneal component of the sciatic nerve. The non-diabetic patients were younger [64 (SD 12) vs. 74 (SD 7) years] and predominantly female (23 vs. 8). The geometric mean of the motor stimulation threshold was 0.26 [95% confidence interval (95% CI) 0.24 to 0.28] mA in non-diabetic and 1.9 (95% CI 1.6 to 2.2) mA in diabetic patients. The geometric mean of the electrical stimulation threshold was significantly (P diabetic compared to non-diabetic patients. The electrical stimulation threshold for a motor response of the sciatic nerve is increased by a factor of 7.2 in patients with diabetic foot gangrene, which might hamper nerve identification.

Sequential variation in brain functional magnetic resonance imaging after peripheral nerve injury: A rat study.

Science.gov (United States)

Onishi, Okihiro; Ikoma, Kazuya; Oda, Ryo; Yamazaki, Tetsuro; Fujiwara, Hiroyoshi; Yamada, Shunji; Tanaka, Masaki; Kubo, Toshikazu

2018-04-23

Although treatment protocols are available, patients experience both acute neuropathic pain and chronic neuropathic pain, hyperalgesia, and allodynia after peripheral nerve injury. The purpose of this study was to identify the brain regions activated after peripheral nerve injury using functional magnetic resonance imaging (fMRI) sequentially and assess the relevance of the imaging results using histological findings. To model peripheral nerve injury in male Sprague-Dawley rats, the right sciatic nerve was crushed using an aneurysm clip, under general anesthesia. We used a 7.04T MRI system. T 2 * weighted image, coronal slice, repetition time, 7 ms; echo time, 3.3 ms; field of view, 30 mm × 30 mm; pixel matrix, 64 × 64 by zero-filling; slice thickness, 2 mm; numbers of slices, 9; numbers of average, 2; and flip angle, 8°. fMR images were acquired during electrical stimulation to the rat's foot sole; after 90 min, c-Fos immunohistochemical staining of the brain was performed in rats with induced peripheral nerve injury for 3, 6, and 9 weeks. Data were pre-processed by realignment in the Statistical Parametric Mapping 8 software. A General Linear Model first level analysis was used to obtain T-values. One week after the injury, significant changes were detected in the cingulate cortex, insular cortex, amygdala, and basal ganglia; at 6 weeks, the brain regions with significant changes in signal density were contracted; at 9 weeks, the amygdala and hippocampus showed activation. Histological findings of the rat brain supported the fMRI findings. We detected sequential activation in the rat brain using fMRI after sciatic nerve injury. Many brain regions were activated during the acute stage of peripheral nerve injury. Conversely, during the chronic stage, activation of the amygdala and hippocampus may be related to chronic-stage hyperalgesia, allodynia, and chronic neuropathic pain. Copyright © 2018 Elsevier B.V. All rights reserved.

Peripheral electrical stimulation in Alzheimer's disease - A randomized controlled trial on cognition and behavior

NARCIS (Netherlands)

van Dijk, Koene R.A.; Scheltens, Philip; Luijpen, Marijn W.; Sergeant, Joseph A.; Scherder, Erik J.A.

2005-01-01

In a number of studies, peripheral electrical nerve stimulation has been applied to Alzheimer's disease (AD) patients who lived in a nursing home. Improvements were observed in memory, verbal fluency, affective behavior, activities of daily living and on the rest-activity rhythm and pupillary light

Brief electrical stimulation accelerates axon regeneration in the peripheral nervous system and promotes sensory axon regeneration in the central nervous system.

Science.gov (United States)

Gordon, Tessa; Udina, Esther; Verge, Valerie M K; de Chaves, Elena I Posse

2009-10-01

Injured peripheral but not central nerves regenerate their axons but functional recovery is often poor. We demonstrate that prolonged periods of axon separation from targets and Schwann cell denervation eliminate regenerative capacity in the peripheral nervous system (PNS). A substantial delay of 4 weeks for all regenerating axons to cross a site of repair of sectioned nerve contributes to the long period of separation. Findings that 1h 20Hz bipolar electrical stimulation accelerates axon outgrowth across the repair site and the downstream reinnervation of denervated muscles in rats and human patients, provides a new and exciting method to improve functional recovery after nerve injuries. Drugs that elevate neuronal cAMP and activate PKA promote axon outgrowth in vivo and in vitro, mimicking the electrical stimulation effect. Rapid expression of neurotrophic factors and their receptors and then of growth associated proteins thereafter via cAMP, is the likely mechanism by which electrical stimulation accelerates axon outgrowth from the site of injury in both peripheral and central nervous systems.

Emerging nanotechnology approaches in tissue engineering for peripheral nerve regeneration.

Science.gov (United States)

Cunha, Carla; Panseri, Silvia; Antonini, Stefania

2011-02-01

Effective nerve regeneration and functional recovery subsequent to peripheral nerve injury is still a clinical challenge. Autologous nerve graft transplantation is a feasible treatment in several clinical cases, but it is limited by donor site morbidity and insufficient donor tissue, impairing complete functional recovery. Tissue engineering has introduced innovative approaches to promote and guide peripheral nerve regeneration by using biomimetic conduits creating favorable microenvironments for nervous ingrowth, but despite the development of a plethora of nerve prostheses, few approaches have as yet entered the clinic. Promising strategies using nanotechnology have recently been proposed, such as the use of scaffolds with functionalized cell-binding domains, the use of guidance channels with cell-scale internally oriented fibers, and the possibility of sustained release of neurotrophic factors. This review addresses the fabrication, advantages, drawbacks, and results achieved by the most recent nanotechnology approaches in view of future solutions for peripheral nerve repair. Peripheral nerve repair strategies are very limited despite numerous advances on the field of neurosciences and regenerative medicine. This review discusses nanotechnology based strategies including scaffolds with functionalized cell binding domains, the use of guidance channels, and the potential use of sustained release neurotropic factors. Copyright © 2011 Elsevier Inc. All rights reserved.

Neuron-Derived ADAM10 Production Stimulates Peripheral Nerve Injury-Induced Neuropathic Pain by Cleavage of E-Cadherin in Satellite Glial Cells.

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Li, Jian; Ouyang, Qing; Chen, Cheng-Wen; Chen, Qian-Bo; Li, Xiang-Nan; Xiang, Zheng-Hua; Yuan, Hong-Bin

2017-09-01

Increasing evidence suggests the potential involvement of metalloproteinase family proteins in the pathogenesis of neuropathic pain, although the underlying mechanisms remain elusive. Using the spinal nerve ligation model, we investigated whether ADAM10 proteins participate in pain regulation. By implementing invitro methods, we produced a purified culture of satellite glial cells to study the underlying mechanisms of ADAM10 in regulating neuropathic pain. Results showed that the ADAM10 protein was expressed in calcitonin gene-related peptide (CGRP)-containing neurons of the dorsal root ganglia, and expression was upregulated following spinal nerve ligation surgery invivo. Intrathecal administration of GI254023X, an ADAM10 selective inhibitor, to the rats one to three days after spinal nerve ligation surgery attenuated the spinal nerve ligation-induced mechanical allodynia and thermal hyperalgesia. Intrathecal injection of ADAM10 recombinant protein simulated pain behavior in normal rats to a similar extent as those treated by spinal nerve ligation surgery. These results raised a question about the relative contribution of ADAM10 in pain regulation. Further results showed that ADAM10 might act by cleaving E-cadherin, which is mainly expressed in satellite glial cells. GI254023X reversed spinal nerve ligation-induced downregulation of E-cadherin and activation of cyclooxygenase 2 after spinal nerve ligation. β-catenin, which creates a complex with E-cadherin in the membranes of satellite glial cells, was also downregulated by spinal nerve ligation surgery in satellite glial cells. Finally, knockdown expression of β-catenin by lentiviral infection in purified satellite glial cells increased expression of inducible nitric oxide synthase and cyclooxygenase 2. Our findings indicate that neuron-derived ADAM10 production stimulates peripheral nerve injury-induced neuropathic pain by cleaving E-cadherin in satellite glial cells. © 2017 American Academy of Pain Medicine

Transection of peripheral nerves, bridging strategies and effect evaluation

NARCIS (Netherlands)

IJkema-Paassen, J; Jansen, K; Gramsbergen, A; Meek, MF

Disruption of peripheral nerves due to trauma is a frequently Occurring clinical problem. Gaps in the nerve are bridged by guiding the regenerating nerves along autologous grafts or artificial guides. This review gives an overview oil the different methods of nerve repair techniques. Conventional

Vagus Nerve Stimulation for Treating Epilepsy

Science.gov (United States)

... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy of Neurology (AAN) is the ...

Ultrasonographic evaluation of the iatrogenic peripheral nerve injuries in upper extremity

International Nuclear Information System (INIS)

Karabay, Nuri; Toros, Tulgar; Ademoglu, Yalcin; Ada, Sait

2010-01-01

The aim of our study is to assess the efficiency of the ultrasonography (US) in the diagnosis of peripheral nerve injury. This study includes nine patients (six radial, one median and two posterior interosseous (PIO) nerves) with peripheral nerve injury diagnosed by clinical and electrophysiological methods in the last 3 years. Preoperatively, an ultrasonographic examination was performed and correlated with physical exam and surgical findings. Five patients, who were diagnosed as peripheral nerve transection by US, underwent surgery. The ultrasonographic findings were concordant with the intraoperative findings. Axonal swelling alone was found in the remaining three patients, who were treated conservatively because of preserved nerve continuity without display of nerve compression. In one patient, we were unable to visualize the nerve due to obesity and soft tissue edema. High-resolution US provide morphological information about the exact location, intensity and extent of the nerve injuries, facilitating the preoperative diagnosis. Thus, US may be a useful method for planning optimal treatment strategy in especially iatrogenic nerve injuries.

Ultrasonographic evaluation of the iatrogenic peripheral nerve injuries in upper extremity

Energy Technology Data Exchange (ETDEWEB)

Karabay, Nuri [Department of Radiology, Hand and Microsurgery and Orthopaedics and Traumatology (EMOT) Hospital, 1418 Sok. No: 14 Kahramanlar, 35230 Izmir (Turkey)], E-mail: nurikarabay@gmail.com; Toros, Tulgar [Department of Orthopaedics and Traumatology, Hand and Microsurgery and Orthopaedics and Traumatology (EMOT) Hospital, 1418 Sok. No: 14 Kahramanlar, 35230 Izmir (Turkey)], E-mail: tulgartoros@yahoo.com; Ademoglu, Yalcin [Department of Orthopaedics and Traumatology, Hand and Microsurgery and Orthopaedics and Traumatology (EMOT) Hospital, 1418 Sok. No: 14 Kahramanlar, 35230 Izmir (Turkey)], E-mail: yalcinademoglu@yahoo.com; Ada, Sait [Department of Orthopaedics and Traumatology, Hand and Microsurgery and Orthopaedics and Traumatology (EMOT) Hospital, 1418 Sok. No: 14 Kahramanlar, 35230 Izmir (Turkey)], E-mail: sait_ada@yahoo.com

2010-02-15

The aim of our study is to assess the efficiency of the ultrasonography (US) in the diagnosis of peripheral nerve injury. This study includes nine patients (six radial, one median and two posterior interosseous (PIO) nerves) with peripheral nerve injury diagnosed by clinical and electrophysiological methods in the last 3 years. Preoperatively, an ultrasonographic examination was performed and correlated with physical exam and surgical findings. Five patients, who were diagnosed as peripheral nerve transection by US, underwent surgery. The ultrasonographic findings were concordant with the intraoperative findings. Axonal swelling alone was found in the remaining three patients, who were treated conservatively because of preserved nerve continuity without display of nerve compression. In one patient, we were unable to visualize the nerve due to obesity and soft tissue edema. High-resolution US provide morphological information about the exact location, intensity and extent of the nerve injuries, facilitating the preoperative diagnosis. Thus, US may be a useful method for planning optimal treatment strategy in especially iatrogenic nerve injuries.

MRI of pathology-proven peripheral nerve amyloidosis

International Nuclear Information System (INIS)

McKenzie, Gavin A.; Broski, Stephen M.; Howe, Benjamin M.; Spinner, Robert J.; Amrami, Kimberly K.; Dispenzieri, Angela; Ringler, Michael D.

2017-01-01

To highlight the MRI characteristics of pathologically proven amyloidosis involving the peripheral nervous system (PNS) and determine the utility of MRI in directing targeted biopsy for aiding diagnosis. A retrospective study was performed for patients with pathologically proven PNS amyloidosis who also underwent MRI of the biopsied or excised nerve. MRI signal characteristics, nerve morphology, associated muscular denervation changes, and the presence of multifocal involvement were detailed. Pathology reports were reviewed to determine subtypes of amyloid. Charts were reviewed to gather patient demographics, neurological symptoms and radiologist interpretation. Four men and three women with a mean age of 62 ± 11 years (range 46-76) were identified. All patients had abnormal findings on EMG with mixed sensorimotor neuropathy. All lesions demonstrated diffuse multifocal neural involvement with T1 hypointensity, T2 hyperintensity, and variable enhancement on MRI. One lesion exhibited superimposed T2 hypointensity. Six of seven patients demonstrated associated muscular denervation changes. Peripheral nerve amyloidosis is rare, and the diagnosis is difficult because of insidious symptom onset, mixed sensorimotor neurologic deficits, and the potential for a wide variety of nerves affected. On MRI, peripheral nerve involvement is most commonly characterized by T1 hypointensity, T2 hyperintensity, variable enhancement, maintenance of the fascicular architecture with fusiform enlargement, multifocal involvement and muscular denervation changes. While this appearance mimics other inflammatory neuropathies, MRI can readily detect neural changes and direct-targeted biopsy, thus facilitating early diagnosis and appropriate management. (orig.)

MRI of pathology-proven peripheral nerve amyloidosis

Energy Technology Data Exchange (ETDEWEB)

McKenzie, Gavin A.; Broski, Stephen M.; Howe, Benjamin M.; Spinner, Robert J.; Amrami, Kimberly K.; Dispenzieri, Angela; Ringler, Michael D. [Mayo Clinic, Department of Musculoskeletal Radiology, Rochester, MN (United States)

2017-01-15

To highlight the MRI characteristics of pathologically proven amyloidosis involving the peripheral nervous system (PNS) and determine the utility of MRI in directing targeted biopsy for aiding diagnosis. A retrospective study was performed for patients with pathologically proven PNS amyloidosis who also underwent MRI of the biopsied or excised nerve. MRI signal characteristics, nerve morphology, associated muscular denervation changes, and the presence of multifocal involvement were detailed. Pathology reports were reviewed to determine subtypes of amyloid. Charts were reviewed to gather patient demographics, neurological symptoms and radiologist interpretation. Four men and three women with a mean age of 62 ± 11 years (range 46-76) were identified. All patients had abnormal findings on EMG with mixed sensorimotor neuropathy. All lesions demonstrated diffuse multifocal neural involvement with T1 hypointensity, T2 hyperintensity, and variable enhancement on MRI. One lesion exhibited superimposed T2 hypointensity. Six of seven patients demonstrated associated muscular denervation changes. Peripheral nerve amyloidosis is rare, and the diagnosis is difficult because of insidious symptom onset, mixed sensorimotor neurologic deficits, and the potential for a wide variety of nerves affected. On MRI, peripheral nerve involvement is most commonly characterized by T1 hypointensity, T2 hyperintensity, variable enhancement, maintenance of the fascicular architecture with fusiform enlargement, multifocal involvement and muscular denervation changes. While this appearance mimics other inflammatory neuropathies, MRI can readily detect neural changes and direct-targeted biopsy, thus facilitating early diagnosis and appropriate management. (orig.)

[RESEARCH PROGRESS OF PERIPHERAL NERVE SURGERY ASSISTED BY Da Vinci ROBOTIC SYSTEM].

Science.gov (United States)

Shen, Jie; Song, Diyu; Wang, Xiaoyu; Wang, Changjiang; Zhang, Shuming

2016-02-01

To summarize the research progress of peripheral nerve surgery assisted by Da Vinci robotic system. The recent domestic and international articles about peripheral nerve surgery assisted by Da Vinci robotic system were reviewed and summarized. Compared with conventional microsurgery, peripheral nerve surgery assisted by Da Vinci robotic system has distinctive advantages, such as elimination of physiological tremors and three-dimensional high-resolution vision. It is possible to perform robot assisted limb nerve surgery using either the traditional brachial plexus approach or the mini-invasive approach. The development of Da Vinci robotic system has revealed new perspectives in peripheral nerve surgery. But it has still been at the initial stage, more basic and clinical researches are still needed.

21 CFR 882.5830 - Implanted diaphragmatic/phrenic nerve stimulator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted diaphragmatic/phrenic nerve stimulator... Implanted diaphragmatic/phrenic nerve stimulator. (a) Identification. An implanted diaphragmatic/phrenic nerve stimulator is a device that provides electrical stimulation of a patient's phrenic nerve to...

Roles of neural stem cells in the repair of peripheral nerve injury.

Science.gov (United States)

Wang, Chong; Lu, Chang-Feng; Peng, Jiang; Hu, Cheng-Dong; Wang, Yu

2017-12-01

Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.

Peripheral Nerve Function and Lower Extremity Muscle Power in Older Men

DEFF Research Database (Denmark)

Ward, Rachel E; Caserotti, Paolo; Faulkner, Kimberly

2014-01-01

To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men.......To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men....

A review of vagus nerve stimulation as a therapeutic intervention

Directory of Open Access Journals (Sweden)

Johnson RL

2018-05-01

Full Text Available Rhaya L Johnson,1 Christopher G Wilson1,2 1Lawrence D Longo MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA; 2Department of Pediatrics, Loma Linda University, Loma Linda, CA, USA Abstract: In this review, we provide an overview of the US Food and Drug Administration (FDA-approved clinical uses of vagus nerve stimulation (VNS as well as information about the ongoing studies and preclinical research to expand the use of VNS to additional applications. VNS is currently FDA approved for therapeutic use in patients aged >12 years with drug-resistant epilepsy and depression. Recent studies of VNS in in vivo systems have shown that it has anti-inflammatory properties which has led to more preclinical research aimed at expanding VNS treatment across a wider range of inflammatory disorders. Although the signaling pathway and mechanism by which VNS affects inflammation remain unknown, VNS has shown promising results in treating chronic inflammatory disorders such as sepsis, lung injury, rheumatoid arthritis (RA, and diabetes. It is also being used to control pain in fibromyalgia and migraines. This new preclinical research shows that VNS bears the promise of being applied to a wider range of therapeutic applications. Keywords: vagus nerve stimulation, pediatrics, inflammation, peripheral nerve stimulation, autonomic circuits

Changes in microtubule-associated protein tau during peripheral nerve injury and regeneration

Directory of Open Access Journals (Sweden)

Guang-bin Zha

2016-01-01

Full Text Available Tau, a primary component of microtubule-associated protein, promotes microtubule assembly and/or disassembly and maintains the stability of the microtubule structure. Although the importance of tau in neurodegenerative diseases has been well demonstrated, whether tau is involved in peripheral nerve regeneration remains unknown. In the current study, we obtained sciatic nerve tissue from adult rats 0, 1, 4, 7, and 14 days after sciatic nerve crush and examined tau mRNA and protein expression levels and the location of tau in the sciatic nerve following peripheral nerve injury. The results from our quantitative reverse transcription polymerase chain reaction analysis showed that compared with the uninjured control sciatic nerve, mRNA expression levels for both tau and tau tubulin kinase 1, a serine/threonine kinase that regulates tau phosphorylation, were decreased following peripheral nerve injury. Our western blot assay results suggested that the protein expression levels of tau and phosphorylated tau initially decreased 1 day post nerve injury but then gradually increased. The results of our immunohistochemical labeling showed that the location of tau protein was not altered by nerve injury. Thus, these results showed that the expression of tau was changed following sciatic nerve crush, suggesting that tau may be involved in peripheral nerve repair and regeneration.

Scaffoldless tissue-engineered nerve conduit promotes peripheral nerve regeneration and functional recovery after tibial nerve injury in rats

Institute of Scientific and Technical Information of China (English)

Aaron M. Adams; Keith W. VanDusen; Tatiana Y. Kostrominova; Jacob P. Mertens; Lisa M. Larkin

2017-01-01

Damage to peripheral nerve tissue may cause loss of function in both the nerve and the targeted muscles it innervates. This study compared the repair capability of engineered nerve conduit (ENC), engineered fibroblast conduit (EFC), and autograft in a 10-mm tibial nerve gap. ENCs were fabricated utilizing primary fibroblasts and the nerve cells of rats on embryonic day 15 (E15). EFCs were fabricated utilizing primary fi-broblasts only. Following a 12-week recovery, nerve repair was assessed by measuring contractile properties in the medial gastrocnemius muscle, distal motor nerve conduction velocity in the lateral gastrocnemius, and histology of muscle and nerve. The autografts, ENCs and EFCs reestablished 96%, 87% and 84% of native distal motor nerve conduction velocity in the lateral gastrocnemius, 100%, 44% and 44% of native specific force of medical gastrocnemius, and 63%, 61% and 67% of native medial gastrocnemius mass, re-spectively. Histology of the repaired nerve revealed large axons in the autograft, larger but fewer axons in the ENC repair, and many smaller axons in the EFC repair. Muscle histology revealed similar muscle fiber cross-sectional areas among autograft, ENC and EFC repairs. In conclusion, both ENCs and EFCs promot-ed nerve regeneration in a 10-mm tibial nerve gap repair, suggesting that the E15 rat nerve cells may not be necessary for nerve regeneration, and EFC alone can suffice for peripheral nerve injury repair.

Higher-order power harmonics of pulsed electrical stimulation modulates corticospinal contribution of peripheral nerve stimulation.

Science.gov (United States)

Chen, Chiun-Fan; Bikson, Marom; Chou, Li-Wei; Shan, Chunlei; Khadka, Niranjan; Chen, Wen-Shiang; Fregni, Felipe

2017-03-03

It is well established that electrical-stimulation frequency is crucial to determining the scale of induced neuromodulation, particularly when attempting to modulate corticospinal excitability. However, the modulatory effects of stimulation frequency are not only determined by its absolute value but also by other parameters such as power at harmonics. The stimulus pulse shape further influences parameters such as excitation threshold and fiber selectivity. The explicit role of the power in these harmonics in determining the outcome of stimulation has not previously been analyzed. In this study, we adopted an animal model of peripheral electrical stimulation that includes an amplitude-adapted pulse train which induces force enhancements with a corticospinal contribution. We report that the electrical-stimulation-induced force enhancements were correlated with the amplitude of stimulation power harmonics during the amplitude-adapted pulse train. In an exploratory analysis, different levels of correlation were observed between force enhancement and power harmonics of 20-80 Hz (r = 0.4247, p = 0.0243), 100-180 Hz (r = 0.5894, p = 0.0001), 200-280 Hz (r = 0.7002, p harmonics. This is a pilot, but important first demonstration that power at high order harmonics in the frequency spectrum of electrical stimulation pulses may contribute to neuromodulation, thus warrant explicit attention in therapy design and analysis.

Role of metallothioneins in peripheral nerve function and regeneration

DEFF Research Database (Denmark)

Ceballos, D; Lago, N; Verdú, E

2003-01-01

The physiological role of the metallothionein (MT) family of proteins during peripheral nerve injury and regeneration was examined in Mt1+ 2 and Mt3 knockout (KO) mice. To this end, the right sciatic nerve was crushed, and the regeneration distance was evaluated by the pinch test 2-7 days....... The improved regeneration observed with the Mt3 KO mice was confirmed by compound nerve action potentials that were recorded from digital nerves at 14 dpl only in this group. We conclude that Mt3 normally inhibits peripheral nerve regeneration........ Moreover, the number of regenerating axons in the distal tibial nerve was significantly higher in Mt3KO mice than in the other two strains at 14 dpl. Immunoreactive profiles to protein gene product 9.5 were present in the epidermis and the sweat glands of the plantar skin of the hindpaw of the Mt3 KO group...

Subcutaneous peripheral nerve stimulation with inter-lead stimulation for axial neck and low back pain: case series and review of the literature.

Science.gov (United States)

Burgher, Abram H; Huntoon, Marc A; Turley, Todd W; Doust, Matthew W; Stearns, Lisa J

2012-01-01

While pain in the extremities often responds to treatment using spinal cord stimulation (SCS), axial pain is notoriously refractory to SCS. Interest in subcutaneous peripheral nerve stimulation (SQ PNS) as an alternative to SCS has emerged, but the most appropriate electrode locations and neurostimulator programming techniques are not yet clear. A retrospective review was conducted of consecutive patients evaluated from August 2009 to December 2010 who had undergone trial of SQ PNS with inter-lead stimulation for axial spine pain. Patients proceeding to implant were followed postoperatively with routine clinical visits and a survey form at last follow-up. Ultrasound was used intraoperatively to ensure placement of electrodes at the appropriate depth in patients with larger body mass index. Primary outcome was patient-reported pain relief at last follow-up. Literature review was conducted by searching MEDLINE (1948-present) and through an unstructured review by the authors. Ten patients underwent trial of SQ PNS and six proceeded to permanent implantation. Fifty percent (3/6) of implanted patients preferred neurostimulation programming that included inter-lead stimulation ("cross-talk"). Average duration of postoperative follow-up was 4.5 months (range 2-9 months). Average patient-reported pain relief at last follow-up was 45% (range 20-80%). One patient required re-operation for migration. Patients not proceeding to implant had paresthesia coverage but no analgesia. SQ PNS is a promising therapy for axial neck and back pain based on a small cohort of patients. Ultrasound was useful to assist with electrode placement at the most appropriate depth beneath the skin. While inter-lead stimulation has been preferred by patients in published reports, we did not find it clearly influenced pain relief. Future investigations should include a randomized, controlled study design, as well as defined implantation technique and neurostimulator programming algorithms. © 2011

A micro-scale printable nanoclip for electrical stimulation and recording in small nerves

Science.gov (United States)

Lissandrello, Charles A.; Gillis, Winthrop F.; Shen, Jun; Pearre, Ben W.; Vitale, Flavia; Pasquali, Matteo; Holinski, Bradley J.; Chew, Daniel J.; White, Alice E.; Gardner, Timothy J.

2017-06-01

Objective. The vision of bioelectronic medicine is to treat disease by modulating the signaling of visceral nerves near various end organs. In small animal models, the nerves of interest can have small diameters and limited surgical access. New high-resolution methods for building nerve interfaces are desirable. In this study, we present a novel nerve interface and demonstrate its use for stimulation and recording in small nerves. Approach. We design and fabricate micro-scale electrode-laden nanoclips capable of interfacing with nerves as small as 50 µm in diameter. The nanoclips are fabricated using a direct laser writing technique with a resolution of 200 nm. The resolution of the printing process allows for incorporation of a number of innovations such as trapdoors to secure the device to the nerve, and quick-release mounts that facilitate keyhole surgery, obviating the need for forceps. The nanoclip can be built around various electrode materials; here we use carbon nanotube fibers for minimally invasive tethering. Main results. We present data from stimulation-evoked responses of the tracheal syringeal (hypoglossal) nerve of the zebra finch, as well as quantification of nerve functionality at various time points post implant, demonstrating that the nanoclip is compatible with healthy nerve activity over sub-chronic timescales. Significance. Our nerve interface addresses key challenges in interfacing with small nerves in the peripheral nervous system. Its small size, ability to remain on the nerve over sub-chronic timescales, and ease of implantation, make it a promising tool for future use in the treatment of disease.

Rodent model for assessing the long term safety and performance of peripheral nerve recording electrodes

Science.gov (United States)

Vasudevan, Srikanth; Patel, Kunal; Welle, Cristin

2017-02-01

Objective. In the US alone, there are approximately 185 000 cases of limb amputation annually, which can reduce the quality of life for those individuals. Current prosthesis technology could be improved by access to signals from the nervous system for intuitive prosthesis control. After amputation, residual peripheral nerves continue to convey motor signals and electrical stimulation of these nerves can elicit sensory percepts. However, current technology for extracting information directly from peripheral nerves has limited chronic reliability, and novel approaches must be vetted to ensure safe long-term use. The present study aims to optimize methods to establish a test platform using rodent model to assess the long term safety and performance of electrode interfaces implanted in the peripheral nerves. Approach. Floating Microelectrode Arrays (FMA, Microprobes for Life Sciences) were implanted into the rodent sciatic nerve. Weekly in vivo recordings and impedance measurements were performed in animals to assess performance and physical integrity of electrodes. Motor (walking track analysis) and sensory (Von Frey) function tests were used to assess change in nerve function due to the implant. Following the terminal recording session, the nerve was explanted and the health of axons, myelin and surrounding tissues were assessed using immunohistochemistry (IHC). The explanted electrodes were visualized under high magnification using scanning electrode microscopy (SEM) to observe any physical damage. Main results. Recordings of axonal action potentials demonstrated notable session-to-session variability. Impedance of the electrodes increased upon implantation and displayed relative stability until electrode failure. Initial deficits in motor function recovered by 2 weeks, while sensory deficits persisted through 6 weeks of assessment. The primary cause of failure was identified as lead wire breakage in all of animals. IHC indicated myelinated and unmyelinated axons

Modern management of epilepsy: Vagus nerve stimulation.

Science.gov (United States)

Ben-Menachem, E

1996-12-01

Vagus nerve stimulation (VNS) was first tried as a treatment for seizure patients in 1988. The idea to stimulate the vagus nerve and disrupt or prevent seizures was proposed by Jacob Zabarra. He observed a consistent finding among several animal studies which indicated that stimulation of the vagus nerve could alter the brain wave patterns of the animals under study. His hypothesis formed the basis for the development of the vagus nerve stimulator, an implantable device similar to a pacemaker, which is implanted in the left chest and attached to the left vagus nerve via a stimulating lead. Once implanted, the stimulator is programmed by a physician to deliver regular stimulation 24 hours a day regardless of seizure activity. Patients can also activate extra 'on-demand' stimulation with a handheld magnet. Clinical studies have demonstrated VNS therapy to be a safe and effective mode of treatment when added to the existing regimen of severe, refractory patients with epilepsy. Efficacy ranges from seizure free to no response with the majority of patients (> 50%) reporting at least a 50% improvement in number of seizures after 1.5 years of treatment. The side-effect profile is unique and mostly includes stimulation-related sensations in the neck and throat. The mechanism of action for VNS is not clearly understood although two theories have emerged. First, the direct connection theory hypothesizes that the anticonvulsant action of VNS is caused by a threshold raising effect of the connections to the nucleus of the solitary tract and on to other structures. The second is the concept that chronic stimulation of the vagus nerve increases the amount of inhibitory neurotransmitters and decreases the amount of excitatory neurotransmitters. Additional research into the optimal use of VNS is ongoing. Animal and clinical research have produced some interesting new data suggesting there are numerous ways to improve the clinical performance of vagus nerve stimulation as a

Fabrication of nerve guidance conduit with luminal filler as scaffold for peripheral nerve repair

International Nuclear Information System (INIS)

Aranilla, Charito T.; Wach, Rodoslaw; Ulanski, Piotr

2015-01-01

Peripheral nerve injury is a serious health concern for society, affecting trauma patients, many of whom acquire life-long disability. The gold standard of treatment for peripheral nerve injury is the use of nerve grafts, wherein nerve autograft or allograft is used to bridge the gap in the damaged nerve. Nerve guidance conduits (NGCs) are an attractive alternative to nerve autografts for aiding in the regeneration of peripheral nerve tissue. NGCs are small cylinders or tubes composed of either natural or synthetic biomaterials that are used to axon regeneration. The ends of the damaged nerve are inserted into either end of the cylinder and the NGC acts both as a connecting bridge for the severed nerve ends as well as a protective shelter for the regenerating nerve. This study aims at fabricating nerve guidance conduits with luminal structure based on synthetic biodegradable and biocompatible polymers such as poly (trimethylene carbonate ) (PTMC), poly (lactic acid) (PLA) and poly (caprolactone) (PCL). Initial base materials for fabrication were PLA acid tubes compared to PCL tubes when prepared by spray and dip-coating methods. The morphology of the tubes where examined by SEM and results showed better porosity of PLA acid tubes compared to PCL tubes when prepared by spraying technique. Poly(lactic acid) was then blended with poly(trimethylene carbonate) at a ratio of 1:4 (5% total polymer content) for further fabrication. Electron beam radiation (25 and 50 kGy) was employed for sterilization and the changes in properties induced by irradiation in comprising polymers were evaluated. The wettability, mechanical thermal properties were not significantly changed by irradiation.In a separate experiment, synthesis of carboxymethyl chitosan hydrogel crosslinked by electron beam radiation was studied to create a luminal filler for PTMC-PLA tubes. Based on proper viscosity of solution before crosslinking, sufficient gel fraction and swelling, 10% w/v concentration of

Mobility-Related Consequences of Reduced Lower-Extremity Peripheral Nerve Function with Age

DEFF Research Database (Denmark)

Ward, Rachel E; Caserotti, P.; Cauley, Jane A

2016-01-01

-dwelling and institutionalized residents, 1 from a range of residential locations, and 1 of patients with peripheral arterial disease. Mean ages ranged from 71-82 years. Nerve function was assessed by vibration threshold (n=2); sensory measures and clinical signs and symptoms of neuropathy (n=2); motor nerve conduction (n=1......The objective of this study is to systematically review the relationship between lower-extremity peripheral nerve function and mobility in older adults. The National Library of Medicine (PubMed) was searched on March 23, 2015 with no limits on publication dates. One reviewer selected original...... research studies of older adults (>= 65 years) that assessed the relationship between lower-extremity peripheral nerve function and mobility-related outcomes. Participants, study design and methods of assessing peripheral nerve impairment were evaluated and results were reported and synthesized. Eight...

Tumors of peripheral nerves; Tumoren der peripheren Nerven

Energy Technology Data Exchange (ETDEWEB)

Ho, Michael [Universitaetsklinikum Zuerich, Institut fuer Diagnostische Radiologie, Zuerich (Switzerland); Lutz, Amelie M. [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

2017-03-15

Differentiation between malignant and benign tumors of peripheral nerves in the early stages is challenging; however, due to the unfavorable prognosis of malignant tumors early identification is required. To show the possibilities for detection, differential diagnosis and clinical management of peripheral nerve tumors by imaging appearance in magnetic resonance (MR) neurography. Review of current literature available in PubMed and MEDLINE, supplemented by the authors' own observations in clinical practice. Although not pathognomonic, several imaging features have been reported for a differentiation between distinct peripheral nerve tumors. The use of MR neurography enables detection and initial differential diagnosis in tumors of peripheral nerves. Furthermore, it plays an important role in clinical follow-up, targeted biopsy and surgical planning. (orig.) [German] Die Unterscheidung zwischen malignen und benignen Tumoren der peripheren Nerven ist im initialen Stadium schwierig. Die Frueherkennung der malignen Tumoren ist aufgrund ihrer unguenstigen Prognose jedoch wichtig. Moeglichkeiten der MR-Neurographie zur Detektion, Artdiagnostik und klinischem Management von Tumoren der peripheren Nerven anhand bildmorphologischer Charakteristika. Zusammenschau der Studienlage mittels PubMed- bzw. MEDLINE-Recherche. Zusaetzlich Darlegung teils unveroeffentlichter Erkenntnisse aus der eigenen klinischen Beobachtung. Wenn auch nicht pathognomonisch, existieren verschiedene Bildgebungszeichen zur moeglichen Unterscheidung verschiedener Tumoren der peripheren Nerven. Die MR-Neurographie ist ein geeignetes bildgebendes Verfahren zur Detektion und ersten Differenzialdiagnose von Tumoren der peripheren Nerven. Zudem kommt ihr besondere Bedeutung bei der Verlaufskontrolle, der gezielten Biopsie und der operativen Planung zu. (orig.)

An update-tissue engineered nerve grafts for the repair of peripheral nerve injuries.

Science.gov (United States)

Patel, Nitesh P; Lyon, Kristopher A; Huang, Jason H

2018-05-01

Peripheral nerve injuries (PNI) are caused by a range of etiologies and result in a broad spectrum of disability. While nerve autografts are the current gold standard for the reconstruction of extensive nerve damage, the limited supply of autologous nerve and complications associated with harvesting nerve from a second surgical site has driven groups from multiple disciplines, including biomedical engineering, neurosurgery, plastic surgery, and orthopedic surgery, to develop a suitable or superior alternative to autografting. Over the last couple of decades, various types of scaffolds, such as acellular nerve grafts (ANGs), nerve guidance conduits, and non-nervous tissues, have been filled with Schwann cells, stem cells, and/or neurotrophic factors to develop tissue engineered nerve grafts (TENGs). Although these have shown promising effects on peripheral nerve regeneration in experimental models, the autograft has remained the gold standard for large nerve gaps. This review provides a discussion of recent advances in the development of TENGs and their efficacy in experimental models. Specifically, TENGs have been enhanced via incorporation of genetically engineered cells, methods to improve stem cell survival and differentiation, optimized delivery of neurotrophic factors via drug delivery systems (DDS), co-administration of platelet-rich plasma (PRP), and pretreatment with chondroitinase ABC (Ch-ABC). Other notable advancements include conduits that have been bioengineered to mimic native nerve structure via cell-derived extracellular matrix (ECM) deposition, and the development of transplantable living nervous tissue constructs from rat and human dorsal root ganglia (DRG) neurons. Grafts composed of non-nervous tissues, such as vein, artery, and muscle, will be briefly discussed.

Peripheral Nerve Injury in Developing Rats Reorganizes Representation Pattern in Motor Cortex

Science.gov (United States)

Donoghue, John P.; Sanes, Jerome N.

1987-02-01

We investigated the effect of neonatal nerve lesions on cerebral motor cortex organization by comparing the cortical motor representation of normal adult rats with adult rats that had one forelimb removed on the day of birth. Mapping of cerebral neocortex with electrical stimulation revealed an altered relationship between the motor cortex and the remaining muscles. Whereas distal forelimb movements are normally elicited at the lowest threshold in the motor cortex forelimb area, the same stimuli activated shoulder and trunk muscles in experimental animals. In addition, an expanded cortical representation of intact body parts was present and there was an absence of a distinct portion of motor cortex. These data demonstrate that representation patterns in motor cortex can be altered by peripheral nerve injury during development.

Role of Schwann cells in the regeneration of penile and peripheral nerves

Directory of Open Access Journals (Sweden)

Lin Wang

2015-01-01

Full Text Available Schwann cells (SCs are the principal glia of the peripheral nervous system. The end point of SC development is the formation of myelinating and nonmyelinating cells which ensheath large and small diameter axons, respectively. They play an important role in axon regeneration after injury, including cavernous nerve injury that leads to erectile dysfunction (ED. Despite improvement in radical prostatectomy surgical techniques, many patients still suffer from ED postoperatively as surgical trauma causes traction injuries and local inflammatory changes in the neuronal microenvironment of the autonomic fibers innervating the penis resulting in pathophysiological alterations in the end organ. The aim of this review is to summarize contemporary evidence regarding: (1 the origin and development of SCs in the peripheral and penile nerve system; (2 Wallerian degeneration and SC plastic change following peripheral and penile nerve injury; (3 how SCs promote peripheral and penile nerve regeneration by secreting neurotrophic factors; (4 and strategies targeting SCs to accelerate peripheral nerve regeneration. We searched PubMed for articles related to these topics in both animal models and human research and found numerous studies suggesting that SCs could be a novel target for treatment of nerve injury-induced ED.

Update on Peripheral Nerve Electrodes for Closed-Loop Neuroprosthetics

Directory of Open Access Journals (Sweden)

Emil H. Rijnbeek

2018-05-01

Full Text Available In this paper various types of electrodes for stimulation and recording activity of peripheral nerves for the control of neuroprosthetic limbs are reviewed. First, an overview of interface devices for (feedback- controlled movement of a prosthetic device is given, after which the focus is on peripheral nervous system (PNS electrodes. Important electrode properties, i.e., longevity and spatial resolution, are defined based upon the usability for neuroprostheses. The cuff electrode, longitudinal intrafascicular electrodes (LIFE, transverse intrafascicular multichannel electrode (TIME, Utah slanted electrode array (USEA, and the regenerative electrode are discussed and assessed on their longevity and spatial resolution. The cuff electrode seems to be a promising electrode for the control of neuroprostheses in the near future, because it shows the best longevity and good spatial resolution and it has been used on human subjects in multiple studies. The other electrodes may be promising in the future, but further research on their longevity and spatial resolution is needed. A more quantitatively uniform study protocol used for all electrodes would allow for a proper comparison of recording and stimulation performance. For example, the discussed electrodes could be compared in a large in vivo study, using one uniform comparison protocol.

Injectable systems and implantable conduits for peripheral nerve repair

International Nuclear Information System (INIS)

Lin, Yen-Chih; Marra, Kacey G

2012-01-01

Acute sensory problems following peripheral nerve injury include pain and loss of sensation. Approximately 360 000 people in the United States suffer from upper extremity paralytic syndromes every year. Restoration of sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. Potential nerve repair therapies have increased in the past decade as the field of tissue engineering expands. The following review describes the use of biomaterials in nerve tissue engineering. Namely, the use of both synthetic and natural biomaterials, including non-degradable and degradable nerve grafts, is addressed. The enhancement of axonal regeneration can be achieved by further modification of the nerve guides. These approaches include injectable hydrogel fillers, controlled drug delivery systems, and cell incorporation. Hydrogels are a class of liquid–gel biomaterials with high water content. Injectable and gelling hydrogels can serve as growth factor delivery vehicles and cell carriers for tissue engineering applications. While natural hydrogels and polymers are suitable for short gap nerve repair, the use of polymers for relatively long gaps remains a clinical challenge. (paper)

Overview of pediatric peripheral facial nerve paralysis: analysis of 40 patients.

Science.gov (United States)

Özkale, Yasemin; Erol, İlknur; Saygı, Semra; Yılmaz, İsmail

2015-02-01

Peripheral facial nerve paralysis in children might be an alarming sign of serious disease such as malignancy, systemic disease, congenital anomalies, trauma, infection, middle ear surgery, and hypertension. The cases of 40 consecutive children and adolescents who were diagnosed with peripheral facial nerve paralysis at Baskent University Adana Hospital Pediatrics and Pediatric Neurology Unit between January 2010 and January 2013 were retrospectively evaluated. We determined that the most common cause was Bell palsy, followed by infection, tumor lesion, and suspected chemotherapy toxicity. We noted that younger patients had generally poorer outcome than older patients regardless of disease etiology. Peripheral facial nerve paralysis has been reported in many countries in America and Europe; however, knowledge about its clinical features, microbiology, neuroimaging, and treatment in Turkey is incomplete. The present study demonstrated that Bell palsy and infection were the most common etiologies of peripheral facial nerve paralysis. © The Author(s) 2014.

Malignant peripheral nerve sheath tumour of the bladder associated with neurofibromatosis I.

LENUS (Irish Health Repository)

O'Brien, Julie

2008-12-01

Neurofibromatosis is a hamartomatous disorder of autonomic peripheral nerve sheaths associated with peripheral nerve sheath tumours. Most tumours are neurofibromas; however, the genitourinary system is rarely involved. We present a rare case of a nerve sheath tumour of the bladder in a young patient, which was discovered to be malignant.

Augmenting nerve regeneration with electrical stimulation.

Science.gov (United States)

Gordon, T; Brushart, T M; Chan, K M

2008-12-01

Poor functional recovery after peripheral nerve injury is generally attributed to irreversible target atrophy. In rats, we addressed the functional outcomes of prolonged neuronal separation from targets (chronic axotomy for up to 1 year) and atrophy of Schwann cells (SCs) in distal nerve stumps, and whether electrical stimulation (ES) accelerates axon regeneration. In carpal tunnel syndrome (CTS) patients with severe axon degeneration and release surgery, we asked whether ES accelerates muscle reinnervation. Reinnervated motor unit (MUs) and regenerating neuron numbers were counted electrophysiologically and with dye-labeling after chronic axotomy, chronic SC denervation and after immediate nerve repair with and without trains of 20 Hz ES for 1 hour to 2 weeks in rats and in CTS patients. Chronic axotomy reduced regenerative capacity to 67% and was alleviated by exogenous growth factors. Reduced regeneration to approximately 10% by SC denervation atrophy was ameliorated by forskolin and transforming growth factor-beta SC reactivation. ES (1 h) accelerated axon outgrowth across the suture site in association with elevated neuronal neurotrophic factor and receptors and in patients, promoted the full reinnervation of thenar muscles in contrast to a non-significant increase in MU numbers in the control group. The rate limiting process of axon outgrowth, progressive deterioration of both neuronal growth capacity and SC support, but not irreversible target atrophy, account for observed poor functional recovery after nerve injury. Brief ES accelerates axon outgrowth and target muscle reinnervation in animals and humans, opening the way to future clinical application to promote functional recovery.

Management of peripheral facial nerve palsy

OpenAIRE

Finsterer, Josef

2008-01-01

Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell?s palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the...

Omental pedicle transposition and suture repair of peripheral nerve ...

African Journals Online (AJOL)

Abu wael

This study aimed to compare the effectiveness of omental pedicle transposition and ... Assessment of the nerve regeneration was based on functional (motor and sensory), ..... peripheral nerve fibers regenerating after crush, multiple crush, and.

Noninvasive transcranial stimulation of rat abducens nerve by focused ultrasound.

Science.gov (United States)

Kim, Hyungmin; Taghados, Seyed Javid; Fischer, Krisztina; Maeng, Lee-So; Park, Shinsuk; Yoo, Seung-Schik

2012-09-01

Nonpharmacologic and nonsurgical transcranial modulation of the nerve function may provide new opportunities in evaluation and treatment of cranial nerve diseases. This study investigates the possibility of using low-intensity transcranial focused ultrasound (FUS) to selectively stimulate the rat abducens nerve located above the base of the skull. FUS (frequencies of 350 kHz and 650 kHz) operating in a pulsed mode was applied to the abducens nerve of Sprague-Dawley rats under stereotactic guidance. The abductive eyeball movement ipsilateral to the side of sonication was observed at 350 kHz, using the 0.36-msec tone burst duration (TBD), 1.5-kHz pulse repetition frequency (PRF), and the overall sonication duration of 200 msec. Histologic and behavioral monitoring showed no signs of disruption in the blood brain barrier (BBB), as well as no damage to the nerves and adjacent brain tissue resulting from the sonication. As a novel functional neuro-modulatory modality, the pulsed application of FUS has potential for diagnostic and therapeutic applications in diseases of the peripheral nervous system. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Nerve growth factor loaded heparin/chitosan scaffolds for accelerating peripheral nerve regeneration.

Science.gov (United States)

Li, Guicai; Xiao, Qinzhi; Zhang, Luzhong; Zhao, Yahong; Yang, Yumin

2017-09-01

Artificial chitosan scaffolds have been widely investigated for peripheral nerve regeneration. However, the effect was not as good as that of autologous grafts and therefore could not meet the clinical requirement. In the present study, the nerve growth factor (NGF) loaded heparin/chitosan scaffolds were fabricated via electrostatic interaction for further improving nerve regeneration. The physicochemical properties including morphology, wettability and composition were measured. The heparin immobilization, NGF loading and release were quantitatively and qualitatively characterized, respectively. The effect of NGF loaded heparin/chitosan scaffolds on nerve regeneration was evaluated by Schwann cells culture for different periods. The results showed that the heparin immobilization and NGF loading did not cause the change of bulk properties of chitosan scaffolds except for morphology and wettability. The pre-immobilization of heparin in chitosan scaffolds could enhance the stability of subsequently loaded NGF. The NGF loaded heparin/chitosan scaffolds could obviously improve the attachment and proliferation of Schwann cells in vitro. More importantly, the NGF loaded heparin/chitosan scaffolds could effectively promote the morphology development of Schwann cells. The study may provide a useful experimental basis to design and develop artificial implants for peripheral nerve regeneration and other tissue regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Cristiana R.; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M.; Mano, João F.; Silva, Tiago H. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Freier, Thomas [MEDOVENT GmbH, Friedrich-Koenig-Str. 3, D-55129 Mainz (Germany); Reis, Rui L. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Oliveira, Joaquim M., E-mail: miguel.oliveira@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal)

2017-02-01

Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

International Nuclear Information System (INIS)

Carvalho, Cristiana R.; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M.; Mano, João F.; Silva, Tiago H.; Freier, Thomas; Reis, Rui L.; Oliveira, Joaquim M.

2017-01-01

Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors.

Directory of Open Access Journals (Sweden)

A B Madhankumar

Full Text Available Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs. Interleukin-13 receptor alpha 2 (IL13Rα2 is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR. This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia

Science.gov (United States)

Longhurst, John C.

2013-01-01

Thinly myelinated Aδ-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 μmol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the

Delayed nerve stimulation promotes axon-protective neurofilament phosphorylation, accelerates immune cell clearance and enhances remyelination in vivo in focally demyelinated nerves.

Directory of Open Access Journals (Sweden)

Nikki A McLean

Full Text Available Rapid and efficient axon remyelination aids in restoring strong electrochemical communication with end organs and in preventing axonal degeneration often observed in demyelinating neuropathies. The signals from axons that can trigger more effective remyelination in vivo are still being elucidated. Here we report the remarkable effect of delayed brief electrical nerve stimulation (ES; 1 hour @ 20 Hz 5 days post-demyelination on ensuing reparative events in a focally demyelinated adult rat peripheral nerve. ES impacted many parameters underlying successful remyelination. It effected increased neurofilament expression and phosphorylation, both implicated in axon protection. ES increased expression of myelin basic protein (MBP and promoted node of Ranvier re-organization, both of which coincided with the early reappearance of remyelinated axons, effects not observed at the same time points in non-stimulated demyelinated nerves. The improved ES-associated remyelination was accompanied by enhanced clearance of ED-1 positive macrophages and attenuation of glial fibrillary acidic protein expression in accompanying Schwann cells, suggesting a more rapid clearance of myelin debris and return of Schwann cells to a nonreactive myelinating state. These benefits of ES correlated with increased levels of brain derived neurotrophic factor (BDNF in the acute demyelination zone, a key molecule in the initiation of the myelination program. In conclusion, the tremendous impact of delayed brief nerve stimulation on enhancement of the innate capacity of a focally demyelinated nerve to successfully remyelinate identifies manipulation of this axis as a novel therapeutic target for demyelinating pathologies.

Delayed nerve stimulation promotes axon-protective neurofilament phosphorylation, accelerates immune cell clearance and enhances remyelination in vivo in focally demyelinated nerves.

Science.gov (United States)

McLean, Nikki A; Popescu, Bogdan F; Gordon, Tessa; Zochodne, Douglas W; Verge, Valerie M K

2014-01-01

Rapid and efficient axon remyelination aids in restoring strong electrochemical communication with end organs and in preventing axonal degeneration often observed in demyelinating neuropathies. The signals from axons that can trigger more effective remyelination in vivo are still being elucidated. Here we report the remarkable effect of delayed brief electrical nerve stimulation (ES; 1 hour @ 20 Hz 5 days post-demyelination) on ensuing reparative events in a focally demyelinated adult rat peripheral nerve. ES impacted many parameters underlying successful remyelination. It effected increased neurofilament expression and phosphorylation, both implicated in axon protection. ES increased expression of myelin basic protein (MBP) and promoted node of Ranvier re-organization, both of which coincided with the early reappearance of remyelinated axons, effects not observed at the same time points in non-stimulated demyelinated nerves. The improved ES-associated remyelination was accompanied by enhanced clearance of ED-1 positive macrophages and attenuation of glial fibrillary acidic protein expression in accompanying Schwann cells, suggesting a more rapid clearance of myelin debris and return of Schwann cells to a nonreactive myelinating state. These benefits of ES correlated with increased levels of brain derived neurotrophic factor (BDNF) in the acute demyelination zone, a key molecule in the initiation of the myelination program. In conclusion, the tremendous impact of delayed brief nerve stimulation on enhancement of the innate capacity of a focally demyelinated nerve to successfully remyelinate identifies manipulation of this axis as a novel therapeutic target for demyelinating pathologies.

Peripheral nerve regeneration with conduits: use of vein tubes

OpenAIRE

Sabongi, Rodrigo Guerra; Fernandes, Marcela; dos Santos, Jo?o Baptista Gomes

2015-01-01

Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent los...

Regeneration of long-distance peripheral nerve defects after delayed reconstruction in healthy and diabetic rats is supported by immunomodulatory chitosan nerve guides

OpenAIRE

Stenberg, Lena; Stã¶ãŸel, Maria; Ronchi, Giulia; Geuna, Stefano; Yin, Yaobin; Mommert, Susanne; Mã¥rtensson, Lisa; Metzen, Jennifer; Grothe, Claudia; Dahlin, Lars B.; Haastert-Talini, Kirsten

2017-01-01

Background Delayed reconstruction of transection or laceration injuries of peripheral nerves is inflicted by a reduced regeneration capacity. Diabetic conditions, more frequently encountered in clinical practice, are known to further impair regeneration in peripheral nerves. Chitosan nerve guides (CNGs) have recently been introduced as a new generation of medical devices for immediate peripheral nerve reconstruction. Here, CNGs were used for 45?days delayed reconstruction of critical length 1...

Case study of physiotherapeutic treatment of patient with diagnosis facial nerve peripheral palsy

OpenAIRE

Zahrádková, Tereza

2015-01-01

Title of Bachelorʼs thesis: Case study of physiotherapeutic treatment of patient with diagnosis facial nerve peripheral palsy. Aim of thesis: Summary of theoretical findings of patientʼs diagnosis, study metodology of physiotherapeutic care, treatment design, monitoring of treatment, and evaluate the effect of patient with diagnosis facial nerve peripheral palsy. Summary: This thesis comprehensively summarizes the findings of of peripheral facial nerve palsy and it's treatment with physiotera...

Late radiation injury to muscle and peripheral nerves

International Nuclear Information System (INIS)

Gillette, E. L.; Mahler, P. A.; Powers, B. E.; Gillette, S. M.; Vujaskovic, Z.

1995-01-01

Late radiation injury to muscles and peripheral nerves is infrequently observed. However, the success of radiation oncology has led to longer patient survival, providing a greater opportunity for late effects to develop, increase in severity and, possibly, impact the quality of life of the patient. In addition, when radiation therapy is combined with surgery and/or chemotherapy, the risk of late complications is likely to increase. It is clear that the incidence of complications involving muscles and nerves increases with time following radiation. The influence of volume has yet to be determined; however, an increased volume is likely to increase the risk of injury to muscles and nerves. Experimental and clinical studies have indicated that the (α(β)) ratio for muscle is approximately 4 Gy and, possibly, 2 Gy for peripheral nerve, indicating the great influence of fractionation on response of these tissues. This is of concern for intraoperative radiation therapy, and for high dose rate brachytherapy. This review of clinical and experimental data discusses the response of muscle and nerves late after radiation therapy. A grading system has been proposed and endpoints suggested

[Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

Science.gov (United States)

Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

2017-06-25

Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

Benign Peripheral Nerve Sheath Tumor in a Wild Toco Toucan ( Ramphastos toco ).

Science.gov (United States)

Carvalho, Marcelo P N; Fernandes, Natalia C C A; Nemer, Viviane C; Neto, Ramiro N Dias; Teixeira, Rodrigo H F; Miranda, Bruna S; Mamprim, Maria J; Catão-Dias, José L; Réssio, Rodrigo A

2016-09-01

Peripheral nerve sheath tumors are a heterogeneous group of neoplasms that comprise neurofibromas, schwannomas, neurilemmomas, and perineuromas. In animals, peripheral nerve sheath neoplasms are most commonly diagnosed in dogs and cattle, followed by horses, goats, and cats, but their occurrence is uncommon in birds. An adult, free-living, male toco (common) toucan ( Ramphastos toco ) was admitted to the zoo animal clinic with weight loss, dehydration, and presence of a soft nodule adhered to the medial portion of the left pectoral muscle. Clinical, cytologic, and computed tomography scan results were indicative of a neoplasm. The toucan died during surgical resection of the mass. Necropsy, histopathologic, and immunohistochemical findings confirmed the diagnosis of benign peripheral nerve sheath tumor. To our knowledge, benign peripheral nerve sheath tumor has not previously been reported in a toucan or any other species in the order Piciformes.

Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect

Energy Technology Data Exchange (ETDEWEB)

Luo, Lihua [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Center of Molecular Medicine, School of Medicine, Hubei University of Arts and Sciences, Xiangyang 441053 (China); Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wang, Xiong; Huselstein, Celine [Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS – Université de Lorraine, Biopôle, 54500 Vandoeuvre-lès-Nancy (France); Chen, Yun, E-mail: yunchen@whu.edu.cn [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

2015-02-20

Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

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

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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...

Effect of Platelet-Rich Fibrin on Peripheral Nerve Regeneration.

Science.gov (United States)

Şenses, Fatma; Önder, Mustafa E; Koçyiğit, Ismail D; Kul, Oğuz; Aydin, Gülümser; Inal, Elem; Atil, Fethi; Tekin, Umut

2016-10-01

This study aimed to evaluate the effect of platelet-rich fibrin (PRF) on peripheral nerve regeneration on the sciatic nerve of rats by using functional, histopathologic, and electrophysiologic analyses. Thirty female Wistar rats were divided randomly into 3 experimental groups. In group 1 (G1), which was the control group, the sciatic nerve was transected and sutured (n = 10). In group 2 (G2), the sciatic nerve was transected, sutured, and then covered with PRF as a membrane (n = 10). In group 3 (G3), the sciatic nerve was transected, sutured by leaving a 5-mm gap, and then covered by PRF as a nerve guide (n = 10). Functional, histopathologic, and electrophysiologic analyses were performed. The total histopathologic semiquantitative score was significantly higher in G1 compared to G2 and G3 (P < 0.05). Myelin thickness and capillaries were significantly lower in G3 compared to G1 (P < 0.05). There was no statistically significant difference between the groups with regard to the functional and electrophysiologic results. The study results suggest that PRF decreases functional recovery in sciatic nerve injury. Further studies are required to determine the efficacy of PRF on peripheral nerve regeneration.

The application of viral vectors to enhance regeneration after peripheral nerve repair

NARCIS (Netherlands)

Tannemaat, Martijn R; Verhaagen, J.; Malessy, Martijn J A

2008-01-01

OBJECTIVE: Despite great advancements in surgical repair techniques, a considerable degree of functional impairment remains in the majority of patients after peripheral nerve reconstruction. New concepts to promote regeneration of the peripheral nerve are needed since it is generally held that

4.7-T diffusion tensor imaging of acute traumatic peripheral nerve injury.

Science.gov (United States)

Boyer, Richard B; Kelm, Nathaniel D; Riley, D Colton; Sexton, Kevin W; Pollins, Alonda C; Shack, R Bruce; Dortch, Richard D; Nanney, Lillian B; Does, Mark D; Thayer, Wesley P

2015-09-01

Diagnosis and management of peripheral nerve injury is complicated by the inability to assess microstructural features of injured nerve fibers via clinical examination and electrophysiology. Diffusion tensor imaging (DTI) has been shown to accurately detect nerve injury and regeneration in crush models of peripheral nerve injury, but no prior studies have been conducted on nerve transection, a surgical emergency that can lead to permanent weakness or paralysis. Acute sciatic nerve injuries were performed microsurgically to produce multiple grades of nerve transection in rats that were harvested 1 hour after surgery. High-resolution diffusion tensor images from ex vivo sciatic nerves were obtained using diffusion-weighted spin-echo acquisitions at 4.7 T. Fractional anisotropy was significantly reduced at the injury sites of transected rats compared with sham rats. Additionally, minor eigenvalues and radial diffusivity were profoundly elevated at all injury sites and were negatively correlated to the degree of injury. Diffusion tensor tractography showed discontinuities at all injury sites and significantly reduced continuous tract counts. These findings demonstrate that high-resolution DTI is a promising tool for acute diagnosis and grading of traumatic peripheral nerve injuries.

Hydrogel derived from porcine decellularized nerve tissue as a promising biomaterial for repairing peripheral nerve defects.

Science.gov (United States)

Lin, Tao; Liu, Sheng; Chen, Shihao; Qiu, Shuai; Rao, Zilong; Liu, Jianghui; Zhu, Shuang; Yan, Liwei; Mao, Haiquan; Zhu, Qingtang; Quan, Daping; Liu, Xiaolin

2018-06-01

Decellularized matrix hydrogels derived from tissues or organs have been used for tissue repair due to their biocompatibility, tunability, and tissue-specific extracellular matrix (ECM) components. However, the preparation of decellularized peripheral nerve matrix hydrogels and their use to repair nerve defects have not been reported. Here, we developed a hydrogel from porcine decellularized nerve matrix (pDNM-G), which was confirmed to have minimal DNA content and retain collagen and glycosaminoglycans content, thereby allowing gelatinization. The pDNM-G exhibited a nanofibrous structure similar to that of natural ECM, and a ∼280-Pa storage modulus at 10 mg/mL similar to that of native neural tissues. Western blot and liquid chromatography tandem mass spectrometry analysis revealed that the pDNM-G consisted mostly of ECM proteins and contained primary ECM-related proteins, including fibronectin and collagen I and IV). In vitro experiments showed that pDNM-G supported Schwann cell proliferation and preserved cell morphology. Additionally, in a 15-mm rat sciatic nerve defect model, pDNM-G was combined with electrospun poly(lactic-acid)-co-poly(trimethylene-carbonate)conduits to bridge the defect, which did not elicit an adverse immune response and promoted the activation of M2 macrophages associated with a constructive remodeling response. Morphological analyses and electrophysiological and functional examinations revealed that the regenerative outcomes achieved by pDNM-G were superior to those by empty conduits and closed to those using rat decellularized nerve matrix allograft scaffolds. These findings indicated that pDNM-G, with its preserved ECM composition and nanofibrous structure, represents a promising biomaterial for peripheral nerve regeneration. Decellularized nerve allografts have been widely used to treat peripheral nerve injury. However, given their limited availability and lack of bioactive factors, efforts have been made to improve the efficacy

Vagal nerve stimulation therapy: what is being stimulated?

Science.gov (United States)

Kember, Guy; Ardell, Jeffrey L; Armour, John A; Zamir, Mair

2014-01-01

Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

Vagal nerve stimulation therapy: what is being stimulated?

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Guy Kember

Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

Ultrasound-guided peripheral nerve blocks: what are the benefits?

DEFF Research Database (Denmark)

Nielsen, Zbigniew Jerzy Koscielniak

2008-01-01

with the MESH terms 'nerve block' and 'ultrasonography'. The following limits were applied: studies with abstracts, only in humans, published in core clinical journals. Trial type: meta-analysis, randomized-controlled trial and clinical trial. RESULTS: When peripheral nerves are adequately imaged by ultrasound...

Peripheral nerve repair: a hot spot analysis on treatment methods from 2010 to 2014

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Guang-yao Liu

2015-01-01

Full Text Available Therapeutic strategies for neurological deficits and for promoting nerve regeneration after peripheral nerve injuries have received much focus in clinical research. Advances in basic research in recent years have increased our understanding of the anatomy of peripheral nerves and the importance of the microenvironment. Various new intervention methods have been developed, but with varying effectiveness. In the present study, we selected 911 papers on different repair methods for peripheral nerve injury from the Web of Science and indexed in the Science Citation Index from 2010 to 2014. We quantitatively examine new repair methods and strategies using bibliometrics, and we discuss the present state of knowledge and the problems and prospects of various repair methods, including nerve transfer, neural transplantation, tissue engineering and genetic engineering. Our findings should help in the study and development of repair methods for peripheral nerve injury.

Sensory nerve cross-anastomosis and electrical muscle stimulation synergistically enhance functional recovery of chronically denervated muscle.

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Willand, Michael P; Holmes, Michael; Bain, James R; de Bruin, Hubert; Fahnestock, Margaret

2014-11-01

Long-term muscle denervation leads to severe and irreversible atrophy coupled with loss of force and motor function. These factors contribute to poor functional recovery following delayed reinnervation. The authors' previous work demonstrated that temporarily suturing a sensory nerve to the distal motor stump (called sensory protection) significantly reduces muscle atrophy and improves function following reinnervation. The authors have also shown that 1 month of electrical stimulation of denervated muscle significantly improves function and reduces atrophy. In this study, the authors tested whether a combination of sensory protection and electrical stimulation would enhance functional recovery more than either treatment alone. Rat gastrocnemius muscles were denervated by cutting the tibial nerve. The peroneal nerve was then sutured to the distal tibial stump following 3 months of treatment (i.e., electrical stimulation, sensory protection, or both). Three months after peroneal repair, functional and histologic measurements were taken. All treatment groups had significantly higher muscle weight (pstimulation or sensory protection alone. The combined treatment also produced motor unit counts significantly greater than sensory protection alone (p<0.05). The combination treatment synergistically reduces atrophy and improves reinnervation and functional measures following delayed nerve repair, suggesting that these approaches work through different mechanisms. The authors' research supports the clinical use of both modalities together following peripheral nerve injury.

Functional evaluation of peripheral nerve regeneration in the rat : walking track analysis

NARCIS (Netherlands)

Varejao, ASP; Meek, MF; Patricio, JAB; Cabrita, AMS

2001-01-01

The experimental model of choice for many peripheral nerve investigators is the rat. Walking track analysis is a useful tool in the evaluation of functional peripheral nerve recovery in the rat. This quantitative method of analyzing hind limbs performance by examining footprints, known as the

The glucuronyltransferase GlcAT-P is required for stretch growth of peripheral nerves in Drosophila.

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Pandey, Rahul; Blanco, Jorge; Udolph, Gerald

2011-01-01

During development, the growth of the animal body is accompanied by a concomitant elongation of the peripheral nerves, which requires the elongation of integrated nerve fibers and the axons projecting therein. Although this process is of fundamental importance to almost all organisms of the animal kingdom, very little is known about the mechanisms regulating this process. Here, we describe the identification and characterization of novel mutant alleles of GlcAT-P, the Drosophila ortholog of the mammalian glucuronyltransferase b3gat1. GlcAT-P mutants reveal shorter larval peripheral nerves and an elongated ventral nerve cord (VNC). We show that GlcAT-P is expressed in a subset of neurons in the central brain hemispheres, in some motoneurons of the ventral nerve cord as well as in central and peripheral nerve glia. We demonstrate that in GlcAT-P mutants the VNC is under tension of shorter peripheral nerves suggesting that the VNC elongates as a consequence of tension imparted by retarded peripheral nerve growth during larval development. We also provide evidence that for growth of peripheral nerve fibers GlcAT-P is critically required in hemocytes; however, glial cells are also important in this process. The glial specific repo gene acts as a modifier of GlcAT-P and loss or reduction of repo function in a GlcAT-P mutant background enhances VNC elongation. We propose a model in which hemocytes are required for aspects of glial cell biology which in turn affects the elongation of peripheral nerves during larval development. Our data also identifies GlcAT-P as a first candidate gene involved in growth of integrated peripheral nerves and therefore establishes Drosophila as an amenable in-vivo model system to study this process at the cellular and molecular level in more detail.

The glucuronyltransferase GlcAT-P is required for stretch growth of peripheral nerves in Drosophila.

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Rahul Pandey

Full Text Available During development, the growth of the animal body is accompanied by a concomitant elongation of the peripheral nerves, which requires the elongation of integrated nerve fibers and the axons projecting therein. Although this process is of fundamental importance to almost all organisms of the animal kingdom, very little is known about the mechanisms regulating this process. Here, we describe the identification and characterization of novel mutant alleles of GlcAT-P, the Drosophila ortholog of the mammalian glucuronyltransferase b3gat1. GlcAT-P mutants reveal shorter larval peripheral nerves and an elongated ventral nerve cord (VNC. We show that GlcAT-P is expressed in a subset of neurons in the central brain hemispheres, in some motoneurons of the ventral nerve cord as well as in central and peripheral nerve glia. We demonstrate that in GlcAT-P mutants the VNC is under tension of shorter peripheral nerves suggesting that the VNC elongates as a consequence of tension imparted by retarded peripheral nerve growth during larval development. We also provide evidence that for growth of peripheral nerve fibers GlcAT-P is critically required in hemocytes; however, glial cells are also important in this process. The glial specific repo gene acts as a modifier of GlcAT-P and loss or reduction of repo function in a GlcAT-P mutant background enhances VNC elongation. We propose a model in which hemocytes are required for aspects of glial cell biology which in turn affects the elongation of peripheral nerves during larval development. Our data also identifies GlcAT-P as a first candidate gene involved in growth of integrated peripheral nerves and therefore establishes Drosophila as an amenable in-vivo model system to study this process at the cellular and molecular level in more detail.

Experimental strategies to promote functional recovery after peripheral nerve injuries.

Science.gov (United States)

Gordon, Tessa; Sulaiman, Olawale; Boyd, J Gordon

2003-12-01

The capacity of Schwann cells (SCs) in the peripheral nervous system to support axonal regeneration, in contrast to the oligodendrocytes in the central nervous system, has led to the misconception that peripheral nerve regeneration always restores function. Here, we consider how prolonged periods of time that injured neurons remain without targets during axonal regeneration (chronic axotomy) and that SCs in the distal nerve stumps remain chronically denervated (chronic denervation) progressively reduce the number of motoneurons that regenerate their axons. We demonstrate the effectiveness of low-dose, brain-derived neurotrophic and glial-derived neurotrophic factors to counteract the effects of chronic axotomy in promoting axonal regeneration. High-dose brain-derived neurotrophic factor (BDNF) on the other hand, acting through the p75 receptor, inhibits axonal regeneration and may be a factor in stopping regenerating axons from forming neuromuscular connections in skeletal muscle. The immunophilin, FK506, is also effective in promoting axonal regeneration after chronic axotomy. Chronic denervation of SCs (>1 month) severely deters axonal regeneration, although the few motor axons that do regenerate to reinnervate muscles become myelinated and form enlarged motor units in the reinnervated muscles. We found that in vitro incubation of chronically denervated SCs with transforming growth factor-beta re-established their growth-supportive phenotype in vivo, consistent with the idea that the interaction between invading macrophages and denervated SCs during Wallerian degeneration is essential to sustain axonal regeneration by promoting the growth-supportive SC phenotype. Finally, we consider the effectiveness of a brief period of 20 Hz electrical stimulation in promoting the regeneration of axons across the surgical gap after nerve repair.

A 63-year-old man with peripheral facial nerve paralysis and a pulmonary lesion.

Science.gov (United States)

Yserbyt, J; Wilms, G; Lievens, Y; Nackaerts, K

2009-01-01

Occasionally, malignant neoplasms may cause peripheral facial nerve paralysis as a presenting symptom. A 63-year-old man was referred to the Emergency Department because of a peripheral facial nerve paralysis, lasting for 10 days. Initial diagnostic examinations revealed no apparent cause for this facial nerve paralysis. Chest X-ray, however, showed a suspicious tumoural mass, located in the right hilar region, as confirmed by CAT scan. The diagnosis of an advanced stage lung adenocarcinoma was finally confirmed by bronchial biopsy. MRI scanning showed diffuse brain metastases and revealed a pontine lesion as the most probable underlying cause of this case of peripheral facial nerve paralysis. Platin-based palliative chemotherapy was given, after an initial pancranial irradiation. According to the MRI findings, the pontine lesion was responsible for the peripheral facial nerve paralysis, as an initial presenting symptom in this case of lung adenocarcinoma. This clinical case of a peripheral facial nerve paralysis was caused by a pontine brain metastasis and illustrates a rather rare presenting symptom of metastatic lung cancer.

Tenascin-C in peripheral nerve morphogenesis.

Science.gov (United States)

Chiquet, M; Wehrle-Haller, B

1994-01-01

The extracellular matrix (ECM) molecule tenascin/cytotactin (TN-C) is expressed at a high level by satellite (glial precursor) cells in developing peripheral nerves of the chick embryo; synthesis of its mRNA peaks at the time period when axonal growth is maximal. When offered as a substrate in vitro, TN-C mediates neurite outgrowth by both motor and sensory neurons. The ability to grow neurites on TN-C is developmentally regulated: sensory neurons from 4-day chick embryos (the stage at which peripheral nerves start to develop) grow immediately and rapidly, whereas neurons from older embryos respond with a long delay. A TN-C domain responsible for this activity is located within the C-terminal (distal) portion of TN-C subunits. Integrin receptors seem to be involved on peripheral neurites because their growth on TN-C is completely blocked by antibodies to beta 1 integrins. In striking contrast to neuronal processes, nerve satellite cells can attach to a TN-C substrate but are completely inhibited in their migratory activity. Artificial substrate borders between tenascin and fibronectin or laminin act as selective barriers that allow neurites to pass while holding up satellite cells. The repulsive action of TN-C on satellite cells is similar to that observed for other cell types and is likely to be mediated by additional TN-C domains. In view of these data, it is surprising that mice seem to develop normally without a functional TN-C gene. TN-C is likely to be redundant, that is, its dual action on cell adhesion is shared by other molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological conduit small gap sleeve bridging method for peripheral nerve injury: regeneration law of nerve fibers in the conduit

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Pei-xun Zhang

2015-01-01

Full Text Available The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair peripheral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good histocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration (2-8 weeks, the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objective and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.

Autistic spectrum disorder, epilepsy, and vagus nerve stimulation.

Science.gov (United States)

Hull, Mariam Mettry; Madhavan, Deepak; Zaroff, Charles M

2015-08-01

In individuals with a comorbid autistic spectrum disorder and medically refractory epilepsy, vagus nerve stimulation may offer the potential of seizure control and a positive behavioral side effect profile. We aimed to examine the behavioral side effect profile using longitudinal and quantitative data and review the potential mechanisms behind behavioral changes. We present a case report of a 10-year-old boy with autistic spectrum disorder and epilepsy, who underwent vagus nerve stimulation subsequent to unsuccessful treatment with antiepileptic medication. Following vagus nerve stimulation implantation, initial, if temporary, improvement was observed in seizure control. Modest improvements were also observed in behavior and development, improvements which were observed independent of seizure control. Vagus nerve stimulation in autistic spectrum disorder is associated with modest behavioral improvement, with unidentified etiology, although several candidates for this improvement are evident.

Genetic analysis of peripheral nerve conduction velocity in twins

NARCIS (Netherlands)

Rijsdijk, F.V.; Boomsma, D.I.; Vernon, P.A.

1995-01-01

We studied variation in peripheral nerve conduction velocity (PNCV) and intelligence in a group of 16-year-old Dutch twins. It has been suggested that both brain nerve conduction velocity and PNCV are positively correlated with intelligence (Reed, 1984) and that heritable differences in NCV may

Peripheral nerve blocks in pediatric anesthesia

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Novaković Dejan

2009-01-01

Full Text Available Introduction Most children undergoing surgery can benefit from regional anesthetic techniques, either as the sole anesthetic regimen or, as usual in pediatric practice, in combination with general anesthesia. The use of peripheral nerve blocks (PNBs in pediatric anesthesia is an effective way to decrease the side-effects and complications associated with central blocks. In spite of their many advantages, including easy performance end efficacy, peripheral nerve blocks are still underused. Objective This article discusses a general approach to PNBs in children and provides data concerning the practice of this regional technique in different age groups. Methods Data from 1,650 procedures were prospectively collected during the period from March 1, 2007 to February 29, 2008. The type of PNB, if any, as well as the patient age were noted. Our patients were divided into four groups: 0-3 years, 4-7 years, 8-12 years and 13-18 years. Results During the investigated period, PNBs as a sole technique or in anesthetized children were performed in 7.45% of cases. Ilioingunal/iliohypogastric nerve block and penile block were the most common (70% of all PNBs distributed mainly among the children between 4-7 years of age (p<0.05. In older children, extremity PNBs predominate in regard to other types of blocks. PNBs are most frequently performed under general anesthesia (85%, so the perineural approach requires a safe technique to avoid nerve damage. Conclusion The observed differences in PNB usage seem to be related to patient age and correlate with common pathology and also with technical availability of PNB performance.

Electrical stimulation promotes regeneration of injured oculomotor nerves in dogs

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Lei Du

2016-01-01

Full Text Available Functional recovery after oculomotor nerve injury is very poor. Electrical stimulation has been shown to promote regeneration of injured nerves. We hypothesized that electrical stimulation would improve the functional recovery of injured oculomotor nerves. Oculomotor nerve injury models were created by crushing the right oculomotor nerves of adult dogs. Stimulating electrodes were positioned in both proximal and distal locations of the lesion, and non-continuous rectangular, biphasic current pulses (0.7 V, 5 Hz were administered 1 hour daily for 2 consecutive weeks. Analysis of the results showed that electrophysiological and morphological recovery of the injured oculomotor nerve was enhanced, indicating that electrical stimulation improved neural regeneration. Thus, this therapy has the potential to promote the recovery of oculomotor nerve dysfunction.

Spinal myoclonus following a peripheral nerve injury: a case report

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Erkol Gokhan

2008-08-01

Full Text Available Abstract Spinal myoclonus is a rare disorder characterized by myoclonic movements in muscles that originate from several segments of the spinal cord and usually associated with laminectomy, spinal cord injury, post-operative, lumbosacral radiculopathy, spinal extradural block, myelopathy due to demyelination, cervical spondylosis and many other diseases. On rare occasions, it can originate from the peripheral nerve lesions and be mistaken for peripheral myoclonus. Careful history taking and electrophysiological evaluation is important in differential diagnosis. The aim of this report is to evaluate the clinical and electrophysiological characteristics and treatment results of a case with spinal myoclonus following a peripheral nerve injury without any structural lesion.

Optogenetic probing of nerve and muscle function after facial nerve lesion in the mouse whisker system

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Bandi, Akhil; Vajtay, Thomas J.; Upadhyay, Aman; Yiantsos, S. Olga; Lee, Christian R.; Margolis, David J.

2018-02-01

Optogenetic modulation of neural circuits has opened new avenues into neuroscience research, allowing the control of cellular activity of genetically specified cell types. Optogenetics is still underdeveloped in the peripheral nervous system, yet there are many applications related to sensorimotor function, pain and nerve injury that would be of great benefit. We recently established a method for non-invasive, transdermal optogenetic stimulation of the facial muscles that control whisker movements in mice (Park et al., 2016, eLife, e14140)1. Here we present results comparing the effects of optogenetic stimulation of whisker movements in mice that express channelrhodopsin-2 (ChR2) selectively in either the facial motor nerve (ChAT-ChR2 mice) or muscle (Emx1-ChR2 or ACTA1-ChR2 mice). We tracked changes in nerve and muscle function before and up to 14 days after nerve transection. Optogenetic 460 nm transdermal stimulation of the distal cut nerve showed that nerve degeneration progresses rapidly over 24 hours. In contrast, the whisker movements evoked by optogenetic muscle stimulation were up-regulated after denervation, including increased maximum protraction amplitude, increased sensitivity to low-intensity stimuli, and more sustained muscle contractions (reduced adaptation). Our results indicate that peripheral optogenetic stimulation is a promising technique for probing the timecourse of functional changes of both nerve and muscle, and holds potential for restoring movement after paralysis induced by nerve damage or motoneuron degeneration.

Optical stimulation of the facial nerve: a surgical tool?

Science.gov (United States)

Richter, Claus-Peter; Teudt, Ingo Ulrik; Nevel, Adam E.; Izzo, Agnella D.; Walsh, Joseph T., Jr.

2008-02-01

One sequela of skull base surgery is the iatrogenic damage to cranial nerves. Devices that stimulate nerves with electric current can assist in the nerve identification. Contemporary devices have two main limitations: (1) the physical contact of the stimulating electrode and (2) the spread of the current through the tissue. In contrast to electrical stimulation, pulsed infrared optical radiation can be used to safely and selectively stimulate neural tissue. Stimulation and screening of the nerve is possible without making physical contact. The gerbil facial nerve was irradiated with 250-μs-long pulses of 2.12 μm radiation delivered via a 600-μm-diameter optical fiber at a repetition rate of 2 Hz. Muscle action potentials were recorded with intradermal electrodes. Nerve samples were examined for possible tissue damage. Eight facial nerves were stimulated with radiant exposures between 0.71-1.77 J/cm2, resulting in compound muscle action potentials (CmAPs) that were simultaneously measured at the m. orbicularis oculi, m. levator nasolabialis, and m. orbicularis oris. Resulting CmAP amplitudes were 0.3-0.4 mV, 0.15-1.4 mV and 0.3-2.3 mV, respectively, depending on the radial location of the optical fiber and the radiant exposure. Individual nerve branches were also stimulated, resulting in CmAP amplitudes between 0.2 and 1.6 mV. Histology revealed tissue damage at radiant exposures of 2.2 J/cm2, but no apparent damage at radiant exposures of 2.0 J/cm2.

Usefulness of muscle denervation as an MRI sign of peripheral nerve pathology

International Nuclear Information System (INIS)

Lisle, D. A.; Johnstone, S. A.

2007-01-01

Full text: Peripheral nerve disorders may be classified into compressive or entrapment neuropathies and non-compressive neuropathies. Muscle denervation recognized on MRI may be a useful sign in the diagnosis of peripheral nerve disorders. Acute or subacute denervation results in prolonged T 2 relaxation time, producing increased signal in skeletal muscle on short tau inversion-recovery and fat-suppressed T 2 -weighted images. Chronic denervation produces fatty atrophy of skeletal muscles, resulting in increased muscle signal on T 1 -weighted images. This review will outline and illustrate the various ways that muscle denervation as seen on MRI may assist in the diagnosis and localization of peripheral nerve disorders

Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

International Nuclear Information System (INIS)

Areti, Aparna; Komirishetty, Prashanth; Kumar, Ashutosh

2017-01-01

Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic pain.

Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

Energy Technology Data Exchange (ETDEWEB)

Areti, Aparna; Komirishetty, Prashanth; Kumar, Ashutosh, E-mail: ashutosh.niperhyd@gov.in

2017-05-01

Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheral neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic pain.

Genipin-Cross-Linked Chitosan Nerve Conduits Containing TNF-α Inhibitors for Peripheral Nerve Repair.

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Zhang, Li; Zhao, Weijia; Niu, Changmei; Zhou, Yujie; Shi, Haiyan; Wang, Yalin; Yang, Yumin; Tang, Xin

2018-07-01

Tissue engineered nerve grafts (TENGs) are considered a promising alternative to autologous nerve grafting, which is considered the "gold standard" clinical strategy for peripheral nerve repair. Here, we immobilized tumor necrosis factor-α (TNF-α) inhibitors onto a nerve conduit, which was introduced into a chitosan (CS) matrix scaffold utilizing genipin (GP) as the crosslinking agent, to fabricate CS-GP-TNF-α inhibitor nerve conduits. The in vitro release kinetics of TNF-α inhibitors from the CS-GP-TNF-α inhibitor nerve conduits were investigated using high-performance liquid chromatography. The in vivo continuous release profile of the TNF-α inhibitors released from the CS-GP-TNF-α inhibitor nerve conduits was measured using an enzyme-linked immunosorbent assay over 14 days. We found that the amount of TNF-α inhibitors released decreased with time after the bridging of the sciatic nerve defects in rats. Moreover, 4 and 12 weeks after surgery, histological analyses and functional evaluations were carried out to assess the influence of the TENG on regeneration. Immunochemistry performed 4 weeks after grafting to assess early regeneration outcomes revealed that the TENG strikingly promoted axonal outgrowth. Twelve weeks after grafting, the TENG accelerated myelin sheath formation, as well as functional restoration. In general, the regenerative outcomes following TENG more closely paralleled findings observed with autologous grafting than the use of the CS matrix scaffold. Collectively, our data indicate that the CS-GP-TNF-α inhibitor nerve conduits comprised an elaborate system for sustained release of TNF-α inhibitors in vitro, while studies in vivo demonstrated that the TENG could accelerate regenerating axonal outgrowth and functional restoration. The introduction of CS-GP-TNF-α-inhibitor nerve conduits into a scaffold may contribute to an efficient and adaptive immune microenvironment that can be used to facilitate peripheral nerve repair.

Brief electrical stimulation improves nerve regeneration after delayed repair in Sprague Dawley rats.

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Elzinga, Kate; Tyreman, Neil; Ladak, Adil; Savaryn, Bohdan; Olson, Jaret; Gordon, Tessa

2015-07-01

Functional recovery after peripheral nerve injury and surgical repair declines with time and distance because the injured neurons without target contacts (chronic axotomy) progressively lose their regenerative capacity and chronically denervated Schwann cells (SCs) atrophy and fail to support axon regeneration. Findings that brief low frequency electrical stimulation (ES) accelerates axon outgrowth and muscle reinnervation after immediate nerve surgery in rats and human patients suggest that ES might improve regeneration after delayed nerve repair. To test this hypothesis, common peroneal (CP) neurons were chronically axotomized and/or tibial (TIB) SCs and ankle extensor muscles were chronically denervated by transection and ligation in rats. The CP and TIB nerves were cross-sutured after three months and subjected to either sham or one hour 20Hz ES. Using retrograde tracing, we found that ES significantly increased the numbers of both motor and sensory neurons that regenerated their axons after a three month period of chronic CP axotomy and/or chronic TIB SC denervation. Muscle and motor unit forces recorded to determine the numbers of neurons that reinnervated gastrocnemius muscle demonstrated that ES significantly increased the numbers of motoneurons that reinnervated chronically denervated muscles. We conclude that electrical stimulation of chronically axotomized motor and sensory neurons is effective in accelerating axon outgrowth into chronically denervated nerve stumps and improving target reinnervation after delayed nerve repair. Possible mechanisms for the efficacy of ES in promoting axon regeneration and target reinnervation after delayed nerve repair include the upregulation of neurotrophic factors. Copyright © 2015 Elsevier Inc. All rights reserved.

Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect.

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Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

2015-02-20

Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

Use of Vagus Nerve Stimulator on Children With Primary Generalized Epilepsy.

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Welch, William P; Sitwat, Bilal; Sogawa, Yoshimi

2018-06-01

To describe the response to vagus nerve stimulator (VNS) in otherwise neurotypical children with medically intractable primary generalized epilepsy. Retrospective chart review of patients who underwent vagus nerve stimulator surgery between January 2011 and December 2015. Eleven patients were identified. Median follow-up duration was 2.5 years (1.2-8.4 years). Prior to vagus nerve stimulator surgery, all patients had at least 1 seizure per week, and 7/11 (64%) had daily seizures. At 1-year follow-up after vagus nerve stimulator, 7/11 (64%) reported improved seizure frequency and 6/11 (55%) reported fewer than 1 seizure per month. Three patients (27%) reported complications related to vagus nerve stimulator surgery, and no patients required device removal. In children with medically intractable primary generalized epilepsy, vagus nerve stimulator is well tolerated and appears to lead to improvement in seizure frequency. Improvement was not attributable to epilepsy classification, age at vagus nerve stimulator implantation, output current, duty cycle, or follow-up duration.

Deficiency in monocarboxylate transporter 1 (MCT1) in mice delays regeneration of peripheral nerves following sciatic nerve crush

KAUST Repository

Morrison, Brett M.; Tsingalia, Akivaga; Vidensky, Svetlana; Lee, Youngjin; Jin, Lin; Farah, Mohamed H.; Lengacher, Sylvain; Magistretti, Pierre J.; Pellerin, Luc; Rothsteinb, Jeffrey D.

2015-01-01

Peripheral nerve regeneration following injury occurs spontaneously, but many of the processes require metabolic energy. The mechanism of energy supply to axons has not previously been determined. In the central nervous system, monocarboxylate transporter 1 (MCT1), expressed in oligodendroglia, is critical for supplying lactate or other energy metabolites to axons. In the current study, MCT1 is shown to localize within the peripheral nervous system to perineurial cells, dorsal root ganglion neurons, and Schwann cells by MCT1 immunofluorescence in wild-type mice and tdTomato fluorescence in MCT1 BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves of MCT1 heterozygous mice are crushed and peripheral nerve regeneration was quantified electrophysiologically and anatomically. Compound muscle action potential (CMAP) recovery is delayed from a median of 21. days in wild-type mice to greater than 38. days in MCT1 heterozygote mice. In fact, half of the MCT1 heterozygote mice have no recovery of CMAP at 42. days, while all of the wild-type mice recovered. In addition, muscle fibers remain 40% more atrophic and neuromuscular junctions 40% more denervated at 42. days post-crush in the MCT1 heterozygote mice than wild-type mice. The delay in nerve regeneration is not only in motor axons, as the number of regenerated axons in the sural sensory nerve of MCT1 heterozygote mice at 4. weeks and tibial mixed sensory and motor nerve at 3. weeks is also significantly reduced compared to wild-type mice. This delay in regeneration may be partly due to failed Schwann cell function, as there is reduced early phagocytosis of myelin debris and remyelination of axon segments. These data for the first time demonstrate that MCT1 is critical for regeneration of both sensory and motor axons in mice following sciatic nerve crush.

Promoting peripheral myelin repair.

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Zhou, Ye; Notterpek, Lucia

2016-09-01

Compared to the central nervous system (CNS), peripheral nerves have a remarkable ability to regenerate and remyelinate. This regenerative capacity to a large extent is dependent on and supported by Schwann cells, the myelin-forming glial cells of the peripheral nervous system (PNS). In a variety of paradigms, Schwann cells are critical in the removal of the degenerated tissue, which is followed by remyelination of newly-regenerated axons. This unique plasticity of Schwann cells has been the target of myelin repair strategies in acute injuries and chronic diseases, such as hereditary demyelinating neuropathies. In one approach, the endogenous regenerative capacity of Schwann cells is enhanced through interventions such as exercise, electrical stimulation or pharmacological means. Alternatively, Schwann cells derived from healthy nerves, or engineered from different tissue sources have been transplanted into the PNS to support remyelination. These transplant approaches can then be further enhanced by exercise and/or electrical stimulation, as well as by the inclusion of biomaterial engineered to support glial cell viability and neurite extension. Advances in our basic understanding of peripheral nerve biology, as well as biomaterial engineering, will further improve the functional repair of myelinated peripheral nerves. Copyright © 2016 Elsevier Inc. All rights reserved.

Gadolinium-enhanced MRI for evaluation of peripheral nerve neuropathy

International Nuclear Information System (INIS)

Hayakawa, Katsuhiko; Kobayashi, Shigeru; Suzuki, Katsuji; Yamada, Mitsuko; Kojima, Motohiro.

1995-01-01

We carried out enhanced MRI for the carpal tunnel syndrome, cubital tunnel syndrome, tarsal tunnel syndrome and anterior interosseous nerve palsy that is entrapment neuropathy. The affected nerve was enhanced in entrapment point. Carpal tunnel syndrome: The enhancement of affected nerve was apparent in 41 of 52 cases (79%). Cubital tunnel syndrome: The enhancement of affected nerve was apparent in 4 of 5 cases (80%). Tarsal tunnel syndrome: The enhancement of affected nerve was apparent in 1 of 1 case. Anterior interosseous nerve palsy: The enhancement of affected nerve was apparent in 3 of 4 cases (75%). The affected nerve was strongly enhanced by Gd-DTPA, indicating the blood-nerve barrier in the affected nerve to be broken and intraneural edema to be produced, e.i., the ability of Gd-DTPA to selectively contrast-enhance a pathologic focus within the peripheral nerve is perhaps its most important clinical applications. (author)

Gadolinium-enhanced MRI for evaluation of peripheral nerve neuropathy

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Katsuhiko [Aikoh Orthopaedic Hospital, Nagoya (Japan); Kobayashi, Shigeru; Suzuki, Katsuji; Yamada, Mitsuko; Kojima, Motohiro

1995-11-01

We carried out enhanced MRI for the carpal tunnel syndrome, cubital tunnel syndrome, tarsal tunnel syndrome and anterior interosseous nerve palsy that is entrapment neuropathy. The affected nerve was enhanced in entrapment point. Carpal tunnel syndrome: The enhancement of affected nerve was apparent in 41 of 52 cases (79%). Cubital tunnel syndrome: The enhancement of affected nerve was apparent in 4 of 5 cases (80%). Tarsal tunnel syndrome: The enhancement of affected nerve was apparent in 1 of 1 case. Anterior interosseous nerve palsy: The enhancement of affected nerve was apparent in 3 of 4 cases (75%). The affected nerve was strongly enhanced by Gd-DTPA, indicating the blood-nerve barrier in the affected nerve to be broken and intraneural edema to be produced, e.i., the ability of Gd-DTPA to selectively contrast-enhance a pathologic focus within the peripheral nerve is perhaps its most important clinical applications. (author).

3D-engineering of Cellularized Conduits for Peripheral Nerve Regeneration

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Hu, Yu; Wu, Yao; Gou, Zhiyuan; Tao, Jie; Zhang, Jiumeng; Liu, Qianqi; Kang, Tianyi; Jiang, Shu; Huang, Siqing; He, Jiankang; Chen, Shaochen; Du, Yanan; Gou, Maling

2016-08-01

Tissue engineered conduits have great promise for bridging peripheral nerve defects by providing physical guiding and biological cues. A flexible method for integrating support cells into a conduit with desired architectures is wanted. Here, a 3D-printing technology is adopted to prepare a bio-conduit with designer structures for peripheral nerve regeneration. This bio-conduit is consisted of a cryopolymerized gelatin methacryloyl (cryoGelMA) gel cellularized with adipose-derived stem cells (ASCs). By modeling using 3D-printed “lock and key” moulds, the cryoGelMA gel is structured into conduits with different geometries, such as the designed multichannel or bifurcating and the personalized structures. The cryoGelMA conduit is degradable and could be completely degraded in 2-4 months in vivo. The cryoGelMA scaffold supports the attachment, proliferation and survival of the seeded ASCs, and up-regulates the expression of their neurotrophic factors mRNA in vitro. After implanted in a rat model, the bio-conduit is capable of supporting the re-innervation across a 10 mm sciatic nerve gap, with results close to that of the autografts in terms of functional and histological assessments. The study describes an indirect 3D-printing technology for fabricating cellularized designer conduits for peripheral nerve regeneration, and could lead to the development of future nerve bio-conduits for clinical use.

Pudendal nerve stimulation and block by a wireless-controlled implantable stimulator in cats.

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Yang, Guangning; Wang, Jicheng; Shen, Bing; Roppolo, James R; de Groat, William C; Tai, Changfeng

2014-07-01

The study aims to determine the functionality of a wireless-controlled implantable stimulator designed for stimulation and block of the pudendal nerve. In five cats under α-chloralose anesthesia, the stimulator was implanted underneath the skin on the left side in the lower back along the sacral spine. Two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves in addition to one bipolar cuff electrode that was implanted on the left side central to the tripolar cuff electrode. The stimulator provided high-frequency (5-20 kHz) biphasic stimulation waveforms to the two tripolar electrodes and low-frequency (1-100 Hz) rectangular pulses to the bipolar electrode. Bladder and urethral pressures were measured to determine the effects of pudendal nerve stimulation (PNS) or block. The maximal (70-100 cmH2O) urethral pressure generated by 20-Hz PNS applied via the bipolar electrode was completely eliminated by the pudendal nerve block induced by the high-frequency stimulation (6-15 kHz, 6-10 V) applied via the two tripolar electrodes. In a partially filled bladder, 20-30 Hz PNS (2-8 V, 0.2 ms) but not 5 Hz stimulation applied via the bipolar electrode elicited a large sustained bladder contraction (45.9 ± 13.4 to 52.0 ± 22 cmH2O). During cystometry, the 5 Hz PNS significantly (p < 0.05) increased bladder capacity to 176.5 ± 27.1% of control capacity. The wireless-controlled implantable stimulator successfully generated the required waveforms for stimulation and block of pudendal nerve, which will be useful for restoring bladder functions after spinal cord injury. © 2013 International Neuromodulation Society.

Mitchell's influence on European studies of peripheral nerve injuries during World War I.

Science.gov (United States)

Koehler, Peter J; Lanska, Douglas J

2004-12-01

Describe the influence of S. Weir Mitchell's (1829-1914) work, and in particular his ideas on causalgia, on European physicians who treated peripheral nerve injuries during World War I (WWI). During the American Civil War (1861-1865), Mitchell studied peripheral nerve injuries with colleagues George Read Morehouse and William Williams Keen. Three monographs resulted from this work. All were important landmarks in the evolution of knowledge of peripheral nerve injuries. A subsequent occasion to improve knowledge came in WWI. The most important European monographs or series on peripheral nerve injuries from WWI were studied with special interest in references to causalgia and Mitchell's works on peripheral nerve injuries. We included works by Tinel, Athanassio-Benisty, Purves-Stewart & Evans and Carter, Foerster and Oppenheim. Tinel and Athanassio-Benisty provided the most detailed information on peripheral nerve injuries and causalgia and often referred to Mitchell. Both mentioned a possible sympathetic origin. Athanassio-Benisty described tremor and other movement disorders in relation to causalgia. Purves-Stewart and Evans mentioned Mitchell and causalgia in the second edition of their book. They advocated the term "thermalgia." Carter, who had access to data of many cases, concentrated his work on causalgia, referring to Mitchell. Foerster provided data of a great number of peripheral nerve injuries, but did not refer to Mitchell. However, he described the symptoms of causalgia cursorily, applying the term Reflexschmerz (reflexpain). Oppenheim was particularly interested in muscle innervation and referred to Mitchell with respect to hypertrichosis and glossy skin. Oppenheim did not use the term causalgia, although he described the syndrome in some of his patients. It wasn't until around 1920 that German physicians devoted significant attention to causalgia and began using the term. Knowledge of peripheral nerve injuries was greatly advanced during and after WWI

[Positions of the implanted stimulating electrodes for artificial facial nerve for inducing contraction of the orbicularis oris muscle in rabbit with peripheral facial paralysis].

Science.gov (United States)

Xu, D Y; Zhao, N J; Zhao, Y X; Luo, D; Sun, Y J; Li, K Y

2017-11-07

Objective: To explore the optimal positions of the implanted stimulating eletrodes for artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the four microelectrodes of the AFN stimulating side, four modes of the implanted positions were divided. In line with different modes, the electrodes were implanted into the affected OOM of the rabbits with unilateral peripheral facial paralysis. AFN output electric stimulation to induce contraction of the affected OOM with uniform stimulating frequency and pulse length in vitro. Then compared the stimulus threshold amplitude and the peak amplitude separately among different modes by SAS 9.3 version statistical software. Results: The differences of the stimulus threshold amplitude and the peak amplitude had no statistically significant separately between the first mode and the second mode ( P >0.05), but there were statistically significant differences between the third mode and the fourth mode ( P <0.05). Both kinds of the amplitudes were approximated between the first mode and the second mode respectively, and higher than those in the third mode or the fourth mode. Furthermore, both kinds of the amplitudes in the fourth mode were higher than those in the third mode. Conclusions: The microelectrodes of the AFN stimulating lateral are implanted into the upper lip with a public microelectrode and an output microelectrode, into the lower lip with an output microelectrode, and into the way, which is located to the angle 40° to 45° about the line joining between the midpoint of the ipsilateral auricle root and the corner of the mouth with an output microelectrode. This is the third positional mode which requires lowest effective stimulus current intensity. Thus the mode is suitable as the optimal placement programme.

Large Extremity Peripheral Nerve Repair

Science.gov (United States)

2016-12-01

LM, de Crombrugghe B. Some recent advances in the chemistry and biology of trans- forming growth factor-beta. J Cell Biol 1987;105:1039e45. 12. Hao Y...SUPPLEMENTARY NOTES 14. ABSTRACT In current war trauma, 20-30% of all extremity injuries and >80% of penetrating injuries being associated with peripheral nerve...through both axonal advance and in revascularization of the graft following placement. We are confident that this technology may allow us to

Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique.

Science.gov (United States)

Kumar, Alok; Sharma, Dk; Sibi, Maj E; Datta, Barun; Gogoi, Biraj

2014-01-01

The established methods of nerve location were based on either proper motor response on nerve stimulation (NS) or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60), or ultrasound guidance (group US, n = 60) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. The median (range) number of skin punctures were 2 (2-4) in group US and 3 (2-5) in group NS (P =0.27). Insufficient block was observed in three patient (5%) of group US and four patients (6.67%) of group NS (P > =0.35). Patient acceptance was similarly good in the two groups. Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique

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Alok Kumar

2014-01-01

Full Text Available Background: The established methods of nerve location were based on either proper motor response on nerve stimulation (NS or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. Methods : A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60, or ultrasound guidance (group US, n = 60 for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. Results: The median (range number of skin punctures were 2 (2-4 in group US and 3 (2-5 in group NS (P =0.27. Insufficient block was observed in three patient (5% of group US and four patients (6.67% of group NS (P > =0.35. Patient acceptance was similarly good in the two groups. Conclusion: Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

General toxicity and peripheral nerve alterations induced by chronic vincristine treatment in the rabbit.

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Norido, F; Finesso, M; Fiorito, C; Marini, P; Favaro, G; Fusco, M; Tessari, F; Prosdocimi, M

1988-05-01

The effects of five 0.3 mg/kg intravenous administrations of vincristine (VCR) at weekly intervals were studied in the rabbit. Body weight gain was impaired starting from the first injection, while gross signs of motor paralysis and hair loss initiated from the third week. At the end of the observation period blood analysis revealed normocytic normochromic anemia, elevated serum creatine kinase, and low serum alkaline phosphatase, whereas all the tested parameters related to liver and kidney functions where within normal limits. The decreased number of red blood cells was the consequence of a complete, although reversible, blockade of staminal hematopoietic activity. Two important indexes of peripheral nerve function were clearly altered at the end of the treatment: (i) the sciatic nerve conduction velocity in vitro was 27% reduced and (ii) the latency between sciatic nerve stimulation and extensor digitorum longus (EDL) twitch in vivo was 34% prolonged. The usefulness of the rabbit as an animal model to study side-effects of VCR treatment is discussed.

Bone Marrow-Derived, Neural-Like Cells Have the Characteristics of Neurons to Protect the Peripheral Nerve in Microenvironment

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Shi-lei Guo

2015-01-01

Full Text Available Effective repair of peripheral nerve defects is difficult because of the slow growth of new axonal growth. We propose that “neural-like cells” may be useful for the protection of peripheral nerve destructions. Such cells should prolong the time for the disintegration of spinal nerves, reduce lesions, and improve recovery. But the mechanism of neural-like cells in the peripheral nerve is still unclear. In this study, bone marrow-derived neural-like cells were used as seed cells. The cells were injected into the distal end of severed rabbit peripheral nerves that were no longer integrated with the central nervous system. Electromyography (EMG, immunohistochemistry, and transmission electron microscopy (TEM were employed to analyze the development of the cells in the peripheral nerve environment. The CMAP amplitude appeared during the 5th week following surgery, at which time morphological characteristics of myelinated nerve fiber formation were observed. Bone marrow-derived neural-like cells could protect the disintegration and destruction of the injured peripheral nerve.

Peripheral Nerve Repair and Prevention of Neuroma Formation

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2014-09-01

bone disease in Neurofibromatosis type I. Molecular genetics and metabolism . 2008;94(1):105-11. doi: 10.1016/j.ymgme.2007.12.004. PubMed PMID...isolated from dog, and continue to develop them in a canine model of peripheral nerve extension- repair as well as characterize their contribution...Task 1: To test the functional contribution of the mouse/human cells (athymic rats) and their canine counterpart ( canine ) in critical size nerve

Ultrasound assessment of selected peripheral nerve pathologies. Part III: Injuries and postoperative evaluation

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Berta Kowalska

2013-03-01

Full Text Available The previous articles of the series devoted to ultrasound diagnostics of peripheral nerves concerned the most common nerve pathologies, i.e. entrapment neuropathies. The aim of the last part of the series is to present ultrasound possibilities in the postoperative control of the peripheral nerves as well as in the diagnostics of the second most common neuropathies of peripheral nerves, i.e. posttraumatic lesions. Early diagnostics of posttraumatic changes is of fundamental importance for the course of treatment and its long-term effects. It aids surgeons in making treatment decisions (whether surgical or conservative. When surgical treatment is necessary, the surgeon, based on US findings, is able to plan a given type of operative method. In certain cases, may even abandon the corrective or reconstructive surgery of the nerve trunk (when there are extensive defects of the nerve trunks and instead, proceed with muscle transfers. Medical literature proposes a range of divisions of the kinds of peripheral nerve injuries depending on, among others, the mechanism or degree of damage. However, the most important issue in the surgeon-diagnostician communication is a detailed description of stumps of the nerve trunks, their distance and location. In the postoperative period, ultrasound is used for monitoring the operative or conservative treatment effects including the determination of the causes of a persistent or recurrent neuropathy. It facilitates decision-making concerning a repeated surgical procedure or assuming a wait-and-see attitude. It is a difficult task for a diagnostician and it requires experience, close cooperation with a clinician and knowledge concerning surgical techniques. Apart from a static assessment, a dynamic assessment of possible adhesions constitutes a crucial element of postoperative examination. This feature distinguishes ultrasound scanning from other methods used in the diagnostics of peripheral neuropathies.

Triple Peripheral Nerve Injury Accompanying to Traumatic Brain Injury: A Case Report

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Ižlknur Can

2014-02-01

Full Text Available Secondary injuries especially extremity fractures may be seen concurrently with traumatic brain injury (TBI. Peripheral nerve damages may accompany to these fractures and may be missed out, especially in acute stage. In this case report; damage of radial, ulnar and median nerves which was developed secondarily to distal humerus fracture that could not be detected in acute stage, in a patient who had motor vehicle accident (MVA. 29-year-old male patient was admitted with weakness in the right upper extremity. 9 months ago, he had traumatic brain injury because of MVA, and fracture of distal humerus was detected in follow-ups. Upon the suspect of the peripheral nerve injury, the diagnosis was confirmed with ENMG. The patient responded well to the rehabilitation program treatment. In a TBI patient, it must be kept in mind that there might be a secondary trauma and therefore peripheral nerve lesions may accompany to TBI.

Paradigms for restoration of somatosensory feedback via stimulation of the peripheral nervous system.

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Pasluosta, Cristian; Kiele, Patrick; Stieglitz, Thomas

2018-04-01

The somatosensory system contributes substantially to the integration of multiple sensor modalities into perception. Tactile sensations, proprioception and even temperature perception are integrated to perceive embodiment of our limbs. Damage of somatosensory networks can severely affect the execution of daily life activities. Peripheral injuries are optimally corrected via direct interfacing of the peripheral nerves. Recent advances in implantable devices, stimulation paradigms, and biomimetic sensors enabled the restoration of natural sensations after amputation of the limb. The refinement of stimulation patterns to deliver natural feedback that can be interpreted intuitively such to prescind from long-learning sessions is crucial to function restoration. For this review, we collected state-of-the-art knowledge on the evolution of stimulation paradigms from single fiber stimulation to the eliciting of multisensory sensations. Data from the literature are structured into six sections: (a) physiology of the somatosensory system; (b) stimulation of single fibers; (c) restoral of multisensory percepts; (d) closure of the control loop in hand prostheses; (e) sensory restoration and the sense of embodiment, and (f) methodologies to assess stimulation outcomes. Full functional recovery demands further research on multisensory integration and brain plasticity, which will bring new paradigms for intuitive sensory feedback in the next generation of limb prostheses. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Fabrication and Optimization of Gelatin/ Nano Bioglass Conduits for Peripheral Nerve Regeneration

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M. Foroutan Koudehi

2014-07-01

Full Text Available Introduction & Objective: Peripheral nerve injury is common in trauma patients and 4.5% of all soft-tissue injuries are accompanied by defects of peripheral nerve. Peripheral nerve injuries can lead to lifetime loss of function and permanent disfigurement. Designed conduits com-prised of natural and synthetic materials are now widely used in the construction of damaged tissues. The aim of this project was to prepare nanocomposite conduits from gelatin and bioglass for damaged peripheral nerve reconstruction. Materials & Methods: In this experimental study,compound water solution of gelatin and nano bioglass synthesized through sol gel method, was made. After preparing the solution, special mandrels were dipped in solution several times and freeze dried in order to be emptied of wa-ter via sublimation. The conduits had the following dimensions: internal diameter: 1.6 mm, outside diameter: 2.2 mm and length about 12 mm. In order to evaluate the biocompatibility of conduits we used cytotoxicity test by Chinese ovary cells and MTT assay by Miapaca-2 (pancreatic cancer cell line. Results: The prepared nano bioglass and conduits were characterized using transmission elec-tron microscopy, scanning electron microscopy, fourier transformed infrared spectroscopy and X-ray diffraction. Results of biocompatibility test showed no sign of cytotoxicity and cells were found to be attached to the pore walls offered by the conduits. Conclusion: According to the results, nano bioglass conduits could be a good candidate for peripheral nerve regeneration. (Sci J Hamadan Univ Med Sci 2014; 21 (2:152-160

Promotion of peripheral nerve regeneration of a peptide compound hydrogel scaffold

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Wei GJ

2013-08-01

Full Text Available Guo-Jun Wei,1 Meng Yao,1 Yan-Song Wang,1 Chang-Wei Zhou,1 De-Yu Wan,1 Peng-Zhen Lei,1 Jian Wen,1 Hong-Wei Lei,2 Da-Ming Dong1 1Department of Orthopaedics, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; 2Department of Rheumatology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China Background: Peripheral nerve injury is a common trauma, but presents a significant challenge to the clinic. Silk-based materials have recently become an important biomaterial for tissue engineering applications due to silk’s biocompatibility and impressive mechanical and degradative properties. In the present study, a silk fibroin peptide (SF16 was designed and used as a component of the hydrogel scaffold for the repair of peripheral nerve injury. Methods: The SF16 peptide’s structure was characterized using spectrophotometry and atomic force microscopy, and the SF16 hydrogel was analyzed using scanning electron microscopy. The effects of the SF16 hydrogel on the viability and growth of live cells was first assessed in vitro, on PC12 cells. The in vivo test model involved the repair of a nerve gap with tubular nerve guides, through which it was possible to identify if the SF16 hydrogel would have the potential to enhance nerve regeneration. In this model physiological saline was set as the negative control, and collagen as the positive control. Walking track analysis and electrophysiological methods were used to evaluate the functional recovery of the nerve at 4 and 8 weeks after surgery. Results: Analysis of the SF16 peptide’s characteristics indicated that it consisted of a well-defined secondary structure and exhibited self-assembly. Results of scanning electron microscopy showed that the peptide based hydrogel may represent a porous scaffold that is viable for repair of peripheral nerve injury. Analysis of cell culture also supported that the hydrogel was an effective

Radiation injury to peripheral and cranial nerves

International Nuclear Information System (INIS)

Giese, W.L.; Kinsella, T.J.

1991-01-01

In this paper, the results of laboratory and clinical investigations regarding the radiosensitivity of peripheral nerve are presented. Before outlining this research the authors briefly review peripheral neuroanatomy and physiology and then discuss variables associated with injury. It is important to remember that radiation injury is multifactorial in nature, and that the relative importance of individual factors is not well understood. Reports up through the middle of this century were fraught with rudimentary dosimetry, primitive investigative methods, and arbitrary endpoints that resulted in widely conflicting conclusions that continue to date

Prostaglandin E1 in conjunction with high doses of vitamin B12 improves nerve conduction velocity of patients with diabetic peripheral neuropathy

Institute of Scientific and Technical Information of China (English)

Jilai Li; Zhirong Wan

2008-01-01

conduction velocity of the median nerve and the common peroneal nerve were determined using an electromyogram electronic stimulator (Neuropack-Ⅱ, Nihon Kohden, Japan).RESULTS: The motor nerve and sensory nerve conduction velocities of the median nerve and the common peroneal nerve were significantly faster after treatment compared to before treatment in all 3 groups (P<0.05-0.01). Compared with the control group, the motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 low-dose treated group and in the vitamin B12 high-dose treated group (P<0.01). The motor nerve and sensory nerve conduction velocities were significantly faster in the vitamin B12 high-dose treated group compared to the vitamin B12 low-dose treated group (P<0.05).CONCLUSl0N: Prostaglandin E1, in conjunction with vitamin B12, can improve neural functional states and speed up peripheral motor nerve and sensory nerve conduction velocity in diabetic peripheral neuropathy. In addition, better effects are achieved using prostaglandin E1 in conjunction with high doses of vitamin B12.

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury.

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Lin, Tao; Qiu, Shuai; Yan, Liwei; Zhu, Shuang; Zheng, Canbin; Zhu, Qingtang; Liu, Xiaolin

2018-05-01

Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. Fifty Sprague-Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit-8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57: 821-828, 2018. © 2017 Wiley Periodicals, Inc.

Design of barrier coatings on kink-resistant peripheral nerve conduits

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Basak Acan Clements

2016-02-01

Full Text Available Here, we report on the design of braided peripheral nerve conduits with barrier coatings. Braiding of extruded polymer fibers generates nerve conduits with excellent mechanical properties, high flexibility, and significant kink-resistance. However, braiding also results in variable levels of porosity in the conduit wall, which can lead to the infiltration of fibrous tissue into the interior of the conduit. This problem can be controlled by the application of secondary barrier coatings. Using a critical size defect in a rat sciatic nerve model, the importance of controlling the porosity of the nerve conduit walls was explored. Braided conduits without barrier coatings allowed cellular infiltration that limited nerve recovery. Several types of secondary barrier coatings were tested in animal studies, including (1 electrospinning a layer of polymer fibers onto the surface of the conduit and (2 coating the conduit with a cross-linked hyaluronic acid-based hydrogel. Sixteen weeks after implantation, hyaluronic acid-coated conduits had higher axonal density, displayed higher muscle weight, and better electrophysiological signal recovery than uncoated conduits or conduits having an electrospun layer of polymer fibers. This study indicates that braiding is a promising method of fabrication to improve the mechanical properties of peripheral nerve conduits and demonstrates the need to control the porosity of the conduit wall to optimize functional nerve recovery.

Platelet-rich plasma, an adjuvant biological therapy to assist peripheral nerve repair

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Mikel Sánchez

2017-01-01

Full Text Available Therapies such as direct tension-free microsurgical repair or transplantation of a nerve autograft, are nowadays used to treat traumatic peripheral nerve injuries (PNI, focused on the enhancement of the intrinsic regenerative potential of injured axons. However, these therapies fail to recreate the suitable cellular and molecular microenvironment of peripheral nerve repair and in some cases, the functional recovery of nerve injuries is incomplete. Thus, new biomedical engineering strategies based on tissue engineering approaches through molecular intervention and scaffolding offer promising outcomes on the field. In this sense, evidence is accumulating in both, preclinical and clinical settings, indicating that platelet-rich plasma products, and fibrin scaffold obtained from this technology, hold an important therapeutic potential as a neuroprotective, neurogenic and neuroinflammatory therapeutic modulator system, as well as enhancing the sensory and motor functional nerve muscle unit recovery.

Estimation of ultrasound reference values for the lower limb peripheral nerves in adults: A cross-sectional study.

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Bedewi, Mohamed Abdelmohsen; Abodonya, Ahmed; Kotb, Mamdouh; Kamal, Sanaa; Mahmoud, Gehan; Aldossari, Khaled; Alqabbani, Abdullah; Swify, Sherine

2018-03-01

The objective of this study is to estimate the reference values for the lower limb peripheral nerves in adults.The demographics and physical characteristics of 69 adult healthy volunteers were evaluated and recorded. The estimated reference values and their correlations with the age, weight, height, body mass index (BMI) were evaluated.The cross sectional area reference values were obtained at 5 predetermined sites for 3 important lower limb peripheral nerves. Our CSA values correlated significantly with age, weight, and BMI. The normal reference values for each nerve were as follows: Tibial nerve at the popliteal fossa 19 mm ± 6.9, tibial nerve at the level of the medial malleolus 12.7 mm ± 4.5, common peroneal nerve at the popliteal fossa 9.5 mm ± 4, common peroneal nerve fibular head 8.9 mm ± 3.2, sural nerve 3.5 mm ± 1.4.The reference values for the lower limb peripheral nerves were identified. These values could be used for future management of peripheral nerve disorders.

Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

International Nuclear Information System (INIS)

Tsoumakidou, Georgia; Garnon, Julien; Ramamurthy, Nitin; Buy, Xavier; Gangi, Afshin

2013-01-01

Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO 2 insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve

Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

Energy Technology Data Exchange (ETDEWEB)

Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Garnon, Julien, E-mail: juliengarnon@gmail.com; Ramamurthy, Nitin, E-mail: nitin_ramamurthy@hotmail.com; Buy, Xavier, E-mail: xbuy@ymail.com; Gangi, Afshin, E-mail: gangi@unistra.fr [University Hospital of Strasbourg (France)

2013-12-15

Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO{sub 2} insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

Age-Dependent Schwann Cell Phenotype Regulation Following Peripheral Nerve Injury.

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Chen, Wayne A; Luo, T David; Barnwell, Jonathan C; Smith, Thomas L; Li, Zhongyu

2017-12-01

Schwann cells are integral to the regenerative capacity of the peripheral nervous system, which declines after adolescence. The mechanisms underlying this decline are poorly understood. This study sought to compare the protein expression of Notch, c-Jun, and Krox-20 after nerve crush injury in adolescent and young adult rats. We hypothesized that these Schwann cell myelinating regulatory factors are down-regulated after nerve injury in an age-dependent fashion. Adolescent (2 months old) and young adult (12 months old) rats (n = 48) underwent sciatic nerve crush injury. Protein expression of Notch, c-Jun, and Krox-20 was quantified by Western blot analysis at 1, 3, and 7 days post-injury. Functional recovery was assessed in a separate group of animals (n = 8) by gait analysis (sciatic functional index) and electromyography (compound motor action potential) over an 8-week post-injury period. Young adult rats demonstrated a trend of delayed onset of the dedifferentiating regulatory factors, Notch and c-Jun, corresponding to the delayed functional recovery observed in young adult rats compared to adolescent rats. Compound motor action potential area was significantly greater in adolescent rats relative to young adult rats, while amplitude and velocity trended toward statistical significance. The process of Schwann cell dedifferentiation following peripheral nerve injury shows different trends with age. These trends of delayed onset of key regulatory factors responsible for Schwann cell myelination may be one of many possible factors mediating the significant differences in functional recovery between adolescent and young adult rats following peripheral nerve injury.

Dose postural control improve following application of transcutaneous electrical nerve stimulation in diabetic peripheral neuropathic patients? A randomized placebo control trial.

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Saadat, Z; Rojhani-Shirazi, Z; Abbasi, L

2017-12-01

peripheral neuropathy is the most common problem of diabetes. Neuropathy leads to lower extremity somatosensory deficits and postural instability in these patients. However, there are not sufficient evidences for improving postural control in these patients. To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with diabetic neuropathy. Twenty eighth patients with diabetic neuropathy (40-55 Y/O) participated in this RCT study. Fourteen patients in case group received TENS and sham TENS was used for control group. Force plate platform was used to extract sway velocity and COP displacement parameters for postural control evaluation. The mean sway velocity and center of pressure displacement along the mediolateral and anteroposterior axes were not significantly different between two groups after TENS application (p>0.05). Application of 5min high frequency TENS on the knee joint could not improve postural control in patients with diabetic neuropathy. Copyright © 2017. Published by Elsevier Ltd.

Thoracoscopic phrenic nerve patch insulation to avoid phrenic nerve stimulation with cardiac resynchronization therapy

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Masatsugu Nozoe, MD, PhD

2014-04-01

Full Text Available A 76-year-old female was implanted with a cardiac resynchronization therapy (CRT device, with the left ventricular lead implanted through a transvenous approach. One day after implantation, diaphragmatic stimulation was observed when the patient was in the seated position, which could not be resolved by device reprogramming. We performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch. The left phrenic nerve was carefully detached from the pericardial adipose tissue, and a Gore-Tex patch was inserted between the phrenic nerve and pericardium using a thoracoscopic technique. This approach represents a potential option for the management of uncontrollable phrenic nerve stimulation during CRT.

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

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

2011-01-01

Cancer chemotherapeutics like paclitaxel and oxaliplatin produce a dose-limiting chronic sensory peripheral neuropathy that is often accompanied by neuropathic pain. The cause of the neuropathy and pain is unknown. In animal models, paclitaxel-evoked and oxaliplatin-evoked painful peripheral neuropathies are accompanied by an increase in the incidence of swollen and vacuolated mitochondria in peripheral nerve axons. It has been proposed that mitochondrial swelling and vacuolation are indicati...

Accelerated axon outgrowth, guidance, and target reinnervation across nerve transection gaps following a brief electrical stimulation paradigm.

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Singh, Bhagat; Xu, Qing-Gui; Franz, Colin K; Zhang, Rumi; Dalton, Colin; Gordon, Tessa; Verge, Valerie M K; Midha, Rajiv; Zochodne, Douglas W

2012-03-01

Regeneration of peripheral nerves is remarkably restrained across transection injuries, limiting recovery of function. Strategies to reverse this common and unfortunate outcome are limited. Remarkably, however, new evidence suggests that a brief extracellular electrical stimulation (ES), delivered at the time of injury, improves the regrowth of motor and sensory axons. In this work, the authors explored and tested this ES paradigm, which was applied proximal to transected sciatic nerves in mice, and identified several novel and compelling impacts of the approach. Using thy-1 yellow fluorescent protein mice with fluorescent axons that allow serial in vivo tracking of regeneration, the morphological, electrophysiological, and behavioral indices of nerve regrowth were measured. The authors show that ES is associated with a 30%-50% improvement in several indices of regeneration: regrowth of axons and their partnered Schwann cells across transection sites, maturation of regenerated fibers in gaps spanning transection zones, and entry of axons into their muscle and cutaneous target zones. In parallel studies, the authors analyzed adult sensory neurons and their response to extracellular ES while plated on a novel microelectrode array construct designed to deliver the identical ES paradigm used in vivo. The ES accelerated neurite outgrowth, supporting the concept of a neuron-autonomous mechanism of action. Taken together, these results support a robust role for brief ES following peripheral nerve injuries in promoting regeneration. Electrical stimulation has a wider repertoire of impact than previously recognized, and its impact in vitro supports the hypothesis that a neuron-specific reprogrammed injury response is recruited by the ES protocol.

Enhanced peripheral nerve regeneration through asymmetrically porous nerve guide conduit with nerve growth factor gradient.

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Oh, Se Heang; Kang, Jun Goo; Kim, Tae Ho; Namgung, Uk; Song, Kyu Sang; Jeon, Byeong Hwa; Lee, Jin Ho

2018-01-01

In this study, we fabricated a nerve guide conduit (NGC) with nerve growth factor (NGF) gradient along the longitudinal direction by rolling a porous polycaprolactone membrane with NGF concentration gradient. The NGF immobilized on the membrane was continuously released for up to 35 days, and the released amount of the NGF from the membrane gradually increased from the proximal to distal NGF ends, which may allow a neurotrophic factor gradient in the tubular NGC for a sufficient period. From the in vitro cell culture experiment, it was observed that the PC12 cells sense the NGF concentration gradient on the membrane for the cell proliferation and differentiation. From the in vivo animal experiment using a long gap (20 mm) sciatic nerve defect model of rats, the NGC with NGF concentration gradient allowed more rapid nerve regeneration through the NGC than the NGC itself and NGC immobilized with uniformly distributed NGF. The NGC with NGF concentration gradient seems to be a promising strategy for the peripheral nerve regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 52-64, 2018. © 2017 Wiley Periodicals, Inc.

GLP-1 signals via ERK in peripheral nerve and prevents nerve dysfunction in diabetic mice

DEFF Research Database (Denmark)

Jolivalt, CG; Fineman, M; Deacon, Carolyn F.

2011-01-01

not affect blood sugar, insulin levels or paw thermal response latencies in either control or diabetic mice. However, the reductions of motor nerve conduction velocity and paw intraepidermal fibre density seen in diabetic mice were attenuated by exenatide treatment. Conclusions: These data show...... that the peripheral nerve of diabetic rodents exhibits functional GLP-1R and suggest that GLP-1R-mediated ERK-signalling in sciatic nerve of diabetic rodents may protect large motor fibre function and small C fibre structure by a mechanism independent of glycaemic control....

Peripheral nerve regeneration with conduits: use of vein tubes.

Science.gov (United States)

Sabongi, Rodrigo Guerra; Fernandes, Marcela; Dos Santos, João Baptista Gomes

2015-04-01

Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.

Peripheral nerve regeneration with conduits: use of vein tubes

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Rodrigo Guerra Sabongi

2015-01-01

Full Text Available Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.

Biomimetic Architectures for Peripheral Nerve Repair: A Review of Biofabrication Strategies.

Science.gov (United States)

Wieringa, Paul A; Gonçalves de Pinho, Ana Rita; Micera, Silvestro; van Wezel, Richard J A; Moroni, Lorenzo

2018-04-01

Biofabrication techniques have endeavored to improve the regeneration of the peripheral nervous system (PNS), but nothing has surpassed the performance of current clinical practices. However, these current approaches have intrinsic limitations that compromise patient care. The "gold standard" autograft provides the best outcomes but requires suitable donor material, while implantable hollow nerve guide conduits (NGCs) can only repair small nerve defects. This review places emphasis on approaches that create structural cues within a hollow NGC lumen in order to match or exceed the regenerative performance of the autograft. An overview of the PNS and nerve regeneration is provided. This is followed by an assessment of reported devices, divided into three major categories: isotropic hydrogel fillers, acting as unstructured interluminal support for regenerating nerves; fibrous interluminal fillers, presenting neurites with topographical guidance within the lumen; and patterned interluminal scaffolds, providing 3D support for nerve growth via structures that mimic native PNS tissue. Also presented is a critical framework to evaluate the impact of reported outcomes. While a universal and versatile nerve repair strategy remains elusive, outlined here is a roadmap of past, present, and emerging fabrication techniques to inform and motivate new developments in the field of peripheral nerve regeneration. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic resonance imaging of peripheral nerve tumours in the upper extremity

DEFF Research Database (Denmark)

Nilsson, Jessica; Sandberg, Kristina; Søe Nielsen, Niels

2009-01-01

Clinical assessment and various diagnostic tools, particularly magnetic resonance imaging (MRI), of tumours of peripheral nerves are used to get an accurate diagnosis and to plan surgical intervention. Our purpose was to examine the usefulness of MRI in assessing nerve tumours in the upper...

Some questions of the treatment of injuries of extremities peripheral nerves

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Виктор Александрович Вишневский

2015-11-01

Full Text Available Trauma of extremities peripheral nerves is on the one of first places on disability and results in stable invalidism in 28–75 % of cases.Mistakes in nerves surgery lead not only to unsatisfactory results and repeated operations but also cause the numerous complications.Indications and contraindications to surgery and conservative treatment, surgical tactics and methods of operations on peripheral nerves depend on trauma prescription, injury character and previous surgical interventions, tissue scarring degree and also level of injury.Aim of research: to carry out an analysis of nerve trunk injuries at traumas of upper and lower extremities, to ground the differentiated approach to treatment depending on traumatization degree and time elapsed since the moment of trauma.Materials and methods: Author carried out retrospective analysis of medical histories of 70 patients with injury of extremities peripheral nerves and the choice of treating tactics and methods. Research was carried out on the base of traumatology department of Dnepropetrovsk clinical hospital № 16 from 2010 to 2013 year.Injuries were divided on cause in primary (65,7 % and secondary (iatrogenic (34,3 %, and also on the degree of conductivity disorder in: neurotmesis (60,0 %, axonotmesis (27,1 % and neuropraxia (12,9 %.Diagnosis of the nerve trunks trauma in clinic was set on the base of clinically-neurological examination using paraclinical methods of research: electroneuromyography, thermal tomography, intramuscular electromyography, bones and joints radiography.Results: According to the results of clinically-neurological and paraclinical methods of research the choice of surgical or conservative treatment depends on dynamics of nerve trunk conductivity disorders: the loss of motor function, sensory impairments and vegetative-trophic impairments in innervation area.The most often were injuries of radial nerve on the level of the shoulder middle one-third – 29 cases (41

Delivery of adipose-derived stem cells in poloxamer hydrogel improves peripheral nerve regeneration.

Science.gov (United States)

Allbright, Kassandra O; Bliley, Jacqueline M; Havis, Emmanuelle; Kim, Deok-Yeol; Dibernardo, Gabriella A; Grybowski, Damian; Waldner, Matthias; James, Isaac B; Sivak, Wesley N; Rubin, J Peter; Marra, Kacey G

2018-02-06

Peripheral nerve damage is associated with high long-term morbidity. Because of beneficial secretome, immunomodulatory effects, and ease of clinical translation, transplantation with adipose-derived stem cells (ASC) represents a promising therapeutic modality. Effect of ASC delivery in poloxamer hydrogel was assessed in a rat sciatic nerve model of critical-sized (1.5 cm) peripheral nerve injury. Nerve/muscle unit regeneration was assessed via immunostaining explanted nerve, quantitative polymerase chain reaction (qPCR), and histological analysis of reinnervating gastrocnemius muscle. On the basis of viability data, 10% poloxamer hydrogel was selected for in vivo study. Six weeks after transection and repair, the group treated with poloxamer delivered ASCs demonstrated longest axonal regrowth. The qPCR results indicated that the inclusion of ASCs appeared to result in expression of factors that aid in reinnervating muscle tissue. Delivery of ASCs in poloxamer addresses multiple facets of the complexity of nerve/muscle unit regeneration, representing a promising avenue for further study. Muscle Nerve, 2018. © 2018 Wiley Periodicals, Inc.

Nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis.

Science.gov (United States)

d'Ovidio, Dario; Noviello, Emilio; Adami, Chiara

2015-07-01

To describe the nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis. Prospective clinical trial. Five captive raptors (Falco peregrinus) aged 6.7 ± 1.3 years. Anaesthesia was induced and maintained with isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine (0.05 mL kg(-1) per nerve) as the sole intra-operative analgesic treatment. Intraoperative physiological variables were recorded every 10 minutes from endotracheal intubation until the end of anaesthesia. Assessment of intraoperative nociception was based on changes in physiological variables above baseline values, while evaluation of postoperative pain relied on species-specific behavioural indicators. The sciatic-femoral nerve block was feasible in raptors and the motor responses following electrical stimulation of both nerves were consistent with those reported in mammalian species. During surgery no rescue analgesia was required. The anaesthesia plane was stable and cardiorespiratory variables did not increase significantly in response to surgical stimulation. Iatrogenic complications, namely nerve damage and local anaesthetic toxicity, did not occur. Recovery was smooth and uneventful. The duration (mean ± SD) of the analgesic effect provided by the nerve block was 130 ± 20 minutes. The sciatic-femoral nerve block as described in dogs and rabbits can be performed in raptors as well. Further clinical trials with a control groups are required to better investigate the analgesic efficacy and the safety of this technique in raptors. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Effect of PACAP in Central and Peripheral Nerve Injuries

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Andras Buki

2012-07-01

Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP is a bioactive peptide with diverse effects in the nervous system. In addition to its more classic role as a neuromodulator, PACAP functions as a neurotrophic factor. Several neurotrophic factors have been shown to play an important role in the endogenous response following both cerebral ischemia and traumatic brain injury and to be effective when given exogenously. A number of studies have shown the neuroprotective effect of PACAP in different models of ischemia, neurodegenerative diseases and retinal degeneration. The aim of this review is to summarize the findings on the neuroprotective potential of PACAP in models of different traumatic nerve injuries. Expression of endogenous PACAP and its specific PAC1 receptor is elevated in different parts of the central and peripheral nervous system after traumatic injuries. Some experiments demonstrate the protective effect of exogenous PACAP treatment in different traumatic brain injury models, in facial nerve and optic nerve trauma. The upregulation of endogenous PACAP and its receptors and the protective effect of exogenous PACAP after different central and peripheral nerve injuries show the important function of PACAP in neuronal regeneration indicating that PACAP may also be a promising therapeutic agent in injuries of the nervous system.

Peripheral innervation patterns of vestibular nerve afferents in the bullfrog utriculus

Science.gov (United States)

Baird, Richard A.; Schuff, N. R.

1994-01-01

Vestibular nerve afferents innervating the bullfrog utriculus differ in their response dynamics and sensitivity to natural stimulation. They also supply hair cells that differ markedly in hair bundle morphology. To examine the peripheral innervation patterns of individual utricular afferents more closely, afferent fibers were labeled by the extracellular injection of horseradish peroxidase (HRP) into the vestibular nerve after sectioning the vestibular nerve medial to Scarpa's ganglion to allow the degeneration of sympathetic and efferent fibers. The peripheral arborizations of individual afferents were then correlated with the diameters of their parent axons, the regions of the macula they innervate, and the number and type of hair cells they supply. The utriculus is divided by the striola, a narrow zone of distinctive morphology, into media and lateral parts. Utiricular afferents were classified as striolar or extrastriolar according to the epithelial entrance of their parent axons and the location of their terminal fields. In general, striolar afferents had thicker parent axons, fewer subepithelial bifurcations, larger terminal fields, and more synaptic endings than afferents in extrstriolar regions. Afferents in a juxtastriolar zone, immediately adjacent to the medial striola, had innervation patterns transitional between those in the striola and more peripheral parts of the medial extrastriola. moast afferents innervated only a single macular zone. The terminal fields of striolar afferents, with the notable exception of a few afferents with thin parent axons, were generally confined to one side of the striola. Hair cells in the bullfrog utriculus have perviously been classified into four types based on hair bundle morphology. Afferents in the extrastriolar and juxtastriolar zones largely or exclusively innervated Type B hair cells, the predominant hair cell type in the utricular macula. Striolar afferents supplied a mixture of four hair cell types, but largely

A novel suture method to place and adjust peripheral nerve catheters

DEFF Research Database (Denmark)

Rothe, C.; Steen-Hansen, C.; Madsen, M. H.

2015-01-01

We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial...

Evaluation of the noradrenergic pathway and alpha-2 and beta-receptors in the modulation of the analgesia induced by transcutaneous electric nerve stimulation of high and low frequencies

OpenAIRE

Vasconcellos, Thiago Henrique Ferreira; Pantaleão, Patricia de Fátima; Teixeira, Dulcinéa Gonçalves; Santos, Ana Paula; Ferreira, Célio Marcos dos Reis

2014-01-01

Transcutaneous electric nerve stimulation is a noninvasive method used in clinical Physiotherapy to control acute or chronic pain. Different theories have been proposed to explain the mechanism of the analgesic action of transcutaneous electric nerve stimulation, as the participation of central and peripheral neurotransmitters. The aim of this study was to evaluate the involvement of noradrenergic pathway and of the receptors alfa-2 and beta in the modulation of analgesia produced by transcut...

[Age-related changes of sensory peripheral nerve system in healthy subjects.

Science.gov (United States)

Voitenkov, V B; Ekusheva, E V; Komancev, V N; Skripchenko, N V; Grigoryev, S G; Klimkin, A V; Aksenova, A I

2017-01-01

Our aim was to present and evaluate age-related changes of peripheral nerves of limbs on a huge population of healthy subjects of different ages. In 2009-2016 subjects aged from 1months to 90 years were studied by nerve conduction velocity studies (NCV). Data of those confirmed healthy was included in our study. In total there were 372 healthy subjects. NCV for nn. Medianus et Ulnaris was registered, with NCV and amplitude of compound sensory action potential (CSAP) being analyzed. There were significant differences on both these parameters between different age groups. Since the childhood the improvement of conduction (which was reflected in rising of CSAP amplitudes and NCV quickening) was registered; from 40-50 years steady decline of both these parameters were observed in both nerves. Conduction studies of peripheral nerves may be implemented in gerontology for early detection of neurophysiology patterns reflecting physiological aging. Also our results may be implemented for accelerated aging detection.

Development of regenerative peripheral nerve interfaces for motor control of neuroprosthetic devices

Science.gov (United States)

Kemp, Stephen W. P.; Urbanchek, Melanie G.; Irwin, Zachary T.; Chestek, Cynthia A.; Cederna, Paul S.

2017-05-01

Traumatic peripheral nerve injuries suffered during amputation commonly results in debilitating neuropathic pain in the affected limb. Modern prosthetic technologies allow for intuitive, simultaneous control of multiple degrees of freedom. However, these state-of-the-art devices require separate, independent control signals for each degree of freedom, which is currently not possible. As a result, amputees reject up to 75% of myoelectric devices preferring instead to use body-powered artificial limbs which offer subtle sensory feedback. Without meaningful and intuitive sensory feedback, even the most advanced myoelectric prostheses remain insensate, burdensome, and are associated with enormous cognitive demand and mental fatigue. The ideal prosthetic device is one which is capable of providing intuitive somatosensory feedback essential for interaction with the environment. Critical to the design of such a bioprosthetic device is the development of a reliable biologic interface between human and machine. This ideal patient-prosthetic interface allows for transmission of both afferent somatosensory information and efferent motor signals for a closed-loop feedback system of neural control. Our lab has developed the Regenerative Peripheral Nerve Interface (RPNI) as a biologic nerve interface designed for stable integration of a prosthetic device with transected peripheral nerves in a residual limb. The RPNI is constructed by surgically implanting the distal end of a transected peripheral nerve into an autogenous muscle graft. Animal experiments in our lab have shown recording of motor signals from RPNI's implanted into both rodents and monkeys. Here, we achieve high amplitude EMG signals with a high signal to noise (SNR) ratio.

Normal tissue tolerance to external beam radiation therapy: Peripheral nerves

International Nuclear Information System (INIS)

Henriques de Figueiredo, B.; Dejean, C.; Sargos, P.; Kantor, G.; Huchet, A.; Mamou, N.; Loiseau, H.

2010-01-01

Plexopathies and peripheral neuropathies appear progressively and with several years delay after radiotherapy. These lesions are observed principally after three clinical situations: supraclavicular and axillar irradiations for breast cancer, pelvic irradiations for various pathologies and limb irradiations for soft tissue sarcomas. Peripheral nerves and plexus (brachial and lumbosacral) are described as serial structures and are supposed to receive less than a given maximum dose linked to the occurrence of late injury. Literature data, mostly ancient, define the maximum tolerable dose to a threshold of 60 Gy and highlight also a great influence of fractionation and high fraction doses. For peripheral nerves, most frequent late effects are pain with significant differences of occurrence between 50 and 60 Gy. At last, associated pathologies (diabetes, vascular pathology, neuropathy) and associated treatments have probably to be taken into account as additional factors, which may increase the risk of these late radiation complications. (authors)

Phrenic Nerve Stimulation: Technology and Clinical Applications.

Science.gov (United States)

Abdunnur, Shane V; Kim, Daniel H

2015-01-01

Phrenic nerve stimulation is a technique used to reanimate the diaphragm of patients with central nervous system etiologies of respiratory insufficiency. Current clinical indications include congenital central hypoventilation syndrome, spinal cord injury above C4, brain stem injury, and idiopathic severe sleep apnea. Presurgical evaluation ensures proper patient selection by validating the intact circuit from the phrenic nerve through alveolar oxygenation. The procedure involves placing leads around the phrenic nerves bilaterally and attaching these leads to radio receivers in a subcutaneous pocket. The rate and amplitude of the current is adjusted via an external radio transmitter. After implantation, each patient progresses through a conditioning phase that strengthens the diaphragm and progressively provides independence from the mechanical ventilator. Studies indicate that patients and families experience an improved quality of life and are satisfied with the results. Phrenic nerve stimulation provides a safe and effective means for reanimating the diaphragm for certain patients with respiratory insufficiency, providing independence from mechanical ventilation. © 2016 S. Karger AG, Basel.

Cortical Reorganization in Dual Innervation by Single Peripheral Nerve.

Science.gov (United States)

Zheng, Mou-Xiong; Shen, Yun-Dong; Hua, Xu-Yun; Hou, Ao-Lin; Zhu, Yi; Xu, Wen-Dong

2017-09-21

Functional recovery after peripheral nerve injury and repair is related with cortical reorganization. However, the mechanism of innervating dual targets by 1 donor nerve is largely unknown. To investigate the cortical reorganization when the phrenic nerve simultaneously innervates the diaphragm and biceps. Total brachial plexus (C5-T1) injury rats were repaired by phrenic nerve-musculocutaneous nerve transfer with end-to-side (n = 15) or end-to-end (n = 15) neurorrhaphy. Brachial plexus avulsion (n = 5) and sham surgery (n = 5) rats were included for control. Behavioral observation, electromyography, and histologic studies were used for confirming peripheral nerve reinnervation. Cortical representations of the diaphragm and reinnervated biceps were studied by intracortical microstimulation techniques before and at months 0.5, 3, 5, 7, and 10 after surgery. At month 0.5 after complete brachial plexus injury, the motor representation of the injured forelimb disappeared. The diaphragm representation was preserved in the "end-to-side" group but absent in the "end-to-end" group. Rhythmic contraction of biceps appeared in "end-to-end" and "end-to-side" groups, and the biceps representation reappeared in the original biceps and diaphragm areas at months 3 and 5. At month 10, it was completely located in the original biceps area in the "end-to-end" group. Part of the biceps representation remained in the original diaphragm area in the "end-to-side" group. Destroying the contralateral motor cortex did not eliminate respiration-related contraction of biceps. The brain tends to resume biceps representation from the original diaphragm area to the original biceps area following phrenic nerve transfer. The original diaphragm area partly preserves reinnervated biceps representation after end-to-side transfer. Copyright © 2017 by the Congress of Neurological Surgeons

Complement inhibition accelerates regeneration in a model of peripheral nerve injury

NARCIS (Netherlands)

Ramaglia, Valeria; Tannemaat, Martijn Rudolf; de Kok, Maryla; Wolterman, Ruud; Vigar, Miriam Ann; King, Rosalind Helen Mary; Morgan, Bryan Paul; Baas, Frank

2009-01-01

Complement (C) activation is a crucial event in peripheral nerve degeneration but its effect on the subsequent regeneration is unknown. Here we show that genetic deficiency of the sixth C component, C6, accelerates axonal regeneration and recovery in a rat model of sciatic nerve injury. Foot-flick

Long pacing pulses reduce phrenic nerve stimulation in left ventricular pacing.

Science.gov (United States)

Hjortshøj, Søren; Heath, Finn; Haugland, Morten; Eschen, Ole; Thøgersen, Anna Margrethe; Riahi, Sam; Toft, Egon; Struijk, Johannes Jan

2014-05-01

Phrenic nerve stimulation is a major obstacle in cardiac resynchronization therapy (CRT). Activation characteristics of the heart and phrenic nerve are different with higher chronaxie for the heart. Therefore, longer pulse durations could be beneficial in preventing phrenic nerve stimulation during CRT due to a decreased threshold for the heart compared with the phrenic nerve. We investigated if long pulse durations decreased left ventricular (LV) thresholds relatively to phrenic nerve thresholds in humans. Eleven patients, with indication for CRT and phrenic nerve stimulation at the intended pacing site, underwent determination of thresholds for the heart and phrenic nerve at different pulse durations (0.3-2.9 milliseconds). The resulting strength duration curves were analyzed by determining chronaxie and rheobase. Comparisons for those parameters were made between the heart and phrenic nerve, and between the models of Weiss and Lapicque as well. In 9 of 11 cases, the thresholds decreased faster for the LV than for the phrenic nerve with increasing pulse duration. In 3 cases, the thresholds changed from unfavorable for LV stimulation to more than a factor 2 in favor of the LV. The greatest change occurred for pulse durations up to 1.5 milliseconds. The chronaxie of the heart was significantly higher than the chronaxie of the phrenic nerve (0.47 milliseconds vs. 0.22 milliseconds [P = 0.029, Lapicque] and 0.79 milliseconds vs. 0.27 milliseconds [P = 0.033, Weiss]). Long pulse durations lead to a decreased threshold of the heart relatively to the phrenic nerve and may prevent stimulation of the phrenic nerve in a clinical setting. © 2013 Wiley Periodicals, Inc.

Effects of intraneural and perineural injection and concentration of Ropivacaine on nerve injury during peripheral nerve block in Wistar rats

Directory of Open Access Journals (Sweden)

Ilvana Hasanbegovic

2013-12-01

Full Text Available Introduction: Injury during peripheral nerve blocks is relatively uncommon, but potentially devastating complication. Recent studies emphasized that location of needle insertion in relationship to the fascicles may be the predominant factor that determines the risk for neurologic complications. However, it is wellestablished that concentration of local anesthetic is also associated with the risk for injury. In this study, we examined the effect of location of injection and concentration of Ropivacaine on risk for neurologic complications. Our hypothesis is that location of the injection is more prognostic for occurrence of nerve injury than the concentration of Ropivacaine.Methods: In experimental design of the study fi fty Wistar rats were used and sciatic nerves were randomized to receive: Ropivacaine or 0.9% NaCl, either intraneurally or perineurally. Pressure data during application was acquired by using a manometer and was analyzed using software package BioBench. Neurologic examination was performed thought the following seven days, there after the rats were sacrificed while sciatic nerves were extracted for histological examination.Results: Independently of tested solution intraneural injections in most of cases resulted with high injection pressure, followed by obvious neurologic defi cit and microscopic destruction of peripheral nerves. Also, low injection pressure, applied either in perineural or intraneural extrafascicular area, resulted with transitory neurologic defi cit and without destruction of the nerve normal histological structure.Conclusions: The main mechanism which leads to neurologic injury combined with peripheral nerve blockade is intrafascicular injection. Higher concentrations of Ropivacaine during intrafascicular applications magnify nerve injury.

Stimulation of the sensory pudendal nerve increases bladder capacity in the rat.

Science.gov (United States)

Hokanson, James A; Langdale, Christopher L; Sridhar, Arun; Grill, Warren M

2018-04-01

Pudendal nerve stimulation is a promising treatment approach for lower urinary tract dysfunction, including symptoms of overactive bladder. Despite some promising clinical studies, there remain many unknowns as to how best to stimulate the pudendal nerve to maximize therapeutic efficacy. We quantified changes in bladder capacity and voiding efficiency during single-fill cystometry in response to electrical stimulation of the sensory branch of the pudendal nerve in urethane-anesthetized female Wistar rats. Increases in bladder capacity were dependent on both stimulation amplitude and rate. Stimulation that produced increases in bladder capacity also led to reductions in voiding efficiency. Also, there was a stimulation carryover effect, and increases in bladder capacity persisted during several nonstimulated trials following stimulated trials. Intravesically administered PGE 2 reduced bladder capacity, producing a model of overactive bladder (OAB), and sensory pudendal nerve stimulation again increased bladder capacity but also reduced voiding efficiency. This study serves as a basis for future studies that seek to maximize the therapeutic efficacy of sensory pudendal nerve stimulation for the symptoms of OAB.

Adipose-Derived Stem Cells Promote Peripheral Nerve Regeneration In Vivo without Differentiation into Schwann-Like Lineage.

Science.gov (United States)

Sowa, Yoshihiro; Kishida, Tsunao; Imura, Tetsuya; Numajiri, Toshiaki; Nishino, Kenichi; Tabata, Yasuhiko; Mazda, Osam

2016-02-01

During recent decades, multipotent stem cells were found to reside in the adipose tissue, and these adipose-derived stem cells were shown to play beneficial roles, like those of Schwann cells, in peripheral nerve regeneration. However, it has not been well established whether adipose-derived stem cells offer beneficial effects to peripheral nerve injuries in vivo as Schwann cells do. Furthermore, the in situ survival and differentiation of adipose-derived stem cells after transplantation at the injured peripheral nerve tissue remain to be fully elucidated. Adipose-derived stem cells and Schwann cells were transplanted with gelatin hydrogel tubes at the artificially blunted sciatic nerve lesion in mice. Neuroregenerative abilities of them were comparably estimated. Cre-loxP-mediated fate tracking was performed to visualize survival in vivo of transplanted adipose-derived stem cells and to investigate whether they differentiated into Schwann linage cells at the peripheral nerve injury site. The transplantation of adipose-derived stem cells promoted regeneration of axons, formation of myelin, and restoration of denervation muscle atrophy to levels comparable to those achieved by Schwann cell transplantation. The adipose-derived stem cells survived for at least 4 weeks after transplantation without differentiating into Schwann cells. Transplanted adipose-derived stem cells did not differentiate into Schwann cells but promoted peripheral nerve regeneration at the injured site. The neuroregenerative ability was comparable to that of Schwann cells. Adipose-derived stem cells at an undifferentiated stage may be used as an alternative cell source for autologous cell therapy for patients with peripheral nerve injury.

Impaired peripheral nerve regeneration in type-2 diabetic mouse model.

Science.gov (United States)

Pham, Vuong M; Tu, Nguyen Huu; Katano, Tayo; Matsumura, Shinji; Saito, Akira; Yamada, Akihiro; Furue, Hidemasa; Ito, Seiji

2018-01-01

Peripheral neuropathy is one of the most common and serious complications of type-2 diabetes. Diabetic neuropathy is characterized by a distal symmetrical sensorimotor polyneuropathy, and its incidence increases in patients 40 years of age or older. In spite of extensive research over decades, there are few effective treatments for diabetic neuropathy besides glucose control and improved lifestyle. The earliest changes in diabetic neuropathy occur in sensory nerve fibers, with initial degeneration and regeneration resulting in pain. To seek its effective treatment, here we prepared a type-2 diabetic mouse model by giving mice 2 injections of streptozotocin and nicotinamide and examining the ability for nerve regeneration by using a sciatic nerve transection-regeneration model previously established by us. Seventeen weeks after the last injection, the mice exhibited symptoms of type-2 diabetes, that is, impaired glucose tolerance, decreased insulin level, mechanical hyperalgesia, and impaired sensory nerve fibers in the plantar skin. These mice showed delayed functional recovery and nerve regeneration by 2 weeks compared with young healthy mice and by 1 week compared with age-matched non-diabetic mice after axotomy. Furthermore, type-2 diabetic mice displayed increased expression of PTEN in their DRG neurons. Administration of a PTEN inhibitor at the cutting site of the nerve for 4 weeks promoted the axonal transport and functional recovery remarkably. This study demonstrates that peripheral nerve regeneration was impaired in type-2 diabetic model and that its combination with sciatic nerve transection is suitable for the study of the pathogenesis and treatment of early diabetic neuropathy. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

US and MR imaging of peripheral nerves in leprosy

International Nuclear Information System (INIS)

Martinoli, C.; Derchi, L.E.; Gandolfo, N.; Bertolotto, M.; Bianchi, S.; Fiallo, P.; Nunzi, E.

2000-01-01

Objective. To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Results. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery.Conclusions. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started. (orig.)

US and MR imaging of peripheral nerves in leprosy

Energy Technology Data Exchange (ETDEWEB)

Martinoli, C. [Department of Radiology ' ' R' ' , DICMI, University of Genoa, Genoa (Italy); Cattedra di Radiologia ' ' R' ' , Universita di Genova, Largo Rosanna Benzi, 8, I-16132 Genoa (Italy); Derchi, L.E.; Gandolfo, N. [Department of Radiology ' ' R' ' , DICMI, University of Genoa, Genoa (Italy); Bertolotto, M. [Department of Radiology, University of Trieste, Strada di Fiume, I-34149 Trieste (Italy); Bianchi, S. [Division de Radiodiagnostic. Hopital Cantonal Huniversitaire, Rue Micheli du Crest, Geneva (Switzerland); Fiallo, P.; Nunzi, E. [Department of Tropical Medicine, University of Genoa, Largo Rosanna Benzi 8, I-16132 Genoa (Italy)

2000-03-30

Objective. To analyze peripheral nerves with ultrasonography (US) and magnetic resonance imaging (MR) in leprosy and assess the role of imaging in leprosy patients. Results. Leprosy nerves were classified into three groups based on imaging appearance: group I consisted of 17 normal-appearing nerves; group II, of 30 enlarged nerves with fascicular abnormalities; group III, of 11 nerves with absent fascicular structure. Group II nerves were from patients subjected to reversal reactions; 75% of patients with group III nerves had a history of erythema nodosum leprosum. Nerve compression in osteofibrous tunnels was identified in 33% of group II and 18% of group III nerves. Doppler US and MR imaging were 74% and 92% sensitive in identifying active reactions, based on detection of endoneural color flow signals, long T2 and Gd enhancement. In 64% of cases, follow-up studies showed decreased color flow and Gd uptake after steroids and decompressive surgery.Conclusions. US and MR imaging are able to detect nerves abnormalities in leprosy. Active reversal reactions are indicated by endoneural color flow signals as well as by an increased T2 signal and Gd enhancement. These signs would suggest rapid progression of nerve damage and a poor prognosis unless antireactional treatment is started. (orig.)

Desert hedgehog promotes ischemia-induced angiogenesis by ensuring peripheral nerve survival.

Science.gov (United States)

Renault, Marie-Ange; Chapouly, Candice; Yao, Qinyu; Larrieu-Lahargue, Frédéric; Vandierdonck, Soizic; Reynaud, Annabel; Petit, Myriam; Jaspard-Vinassa, Béatrice; Belloc, Isabelle; Traiffort, Elisabeth; Ruat, Martial; Duplàa, Cécile; Couffinhal, Thierry; Desgranges, Claude; Gadeau, Alain-Pierre

2013-03-01

Blood vessel growth and patterning have been shown to be regulated by nerve-derived signals. Desert hedgehog (Dhh), one of the Hedgehog family members, is expressed by Schwann cells of peripheral nerves. The purpose of this study was to investigate the contribution of Dhh to angiogenesis in the setting of ischemia. We induced hindlimb ischemia in wild-type and Dhh(-/-) mice. First, we found that limb perfusion is significantly impaired in the absence of Dhh. This effect is associated with a significant decrease in capillary and artery density in Dhh(-/-). By using mice in which the Hedgehog signaling pathway effector Smoothened was specifically invalidated in endothelial cells, we demonstrated that Dhh does not promote angiogenesis by a direct activation of endothelial cells. On the contrary, we found that Dhh promotes peripheral nerve survival in the ischemic muscle and, by doing so, maintains the pool of nerve-derived proangiogenic factors. Consistently, we found that denervation of the leg, immediately after the onset of ischemia, severely impairs ischemia-induced angiogenesis and decreases expression of vascular endothelial growth factor A, angiopoietin 1, and neurotrophin 3 in the ischemic muscle. This study demonstrates the crucial roles of nerves and factors regulating nerve physiology in the setting of ischemia-induced angiogenesis.

Sensation, mechanoreceptor, and nerve fiber function after nerve regeneration

DEFF Research Database (Denmark)

Krarup, Christian; Rosén, Birgitta; Boeckstyns, Michel

2017-01-01

Objective: Sensation is essential for recovery after peripheral nerve injury. However, the relationship between sensory modalities and function of regenerated fibers is uncertain. We have investigated the relationships between touch threshold, tactile gnosis, and mechanoreceptor and sensory fiber...... function after nerve regeneration. Methods: Twenty-one median or ulnar nerve lesions were repaired by a collagen nerve conduit or direct suture. Quantitative sensory hand function and sensory conduction studies by near-nerve technique, including tactile stimulation of mechanoreceptors, were followed for 2...... years, and results were compared to noninjured hands. Results: At both repair methods, touch thresholds at the finger tips recovered to 81 ± 3% and tactile gnosis only to 20 ± 4% (p nerve action potentials (SNAPs) remained dispersed and areas recovered to 23 ± 2...

APP overexpression prevents neuropathic pain and motoneuron death after peripheral nerve injury in mice.

Science.gov (United States)

Kotulska, Katarzyna; Larysz-Brysz, Magdalena; LePecheur, Marie; Marcol, Wiesław; Lewin-Kowalik, Joanna; Paly, Evelyn; London, Jacqueline

2010-03-16

Despite general capacity of peripheral nervous system to regenerate, peripheral nerve injury is often followed by incomplete recovery of function and sometimes burdened by neuropathic pain. Amyloid precursor protein (APP) was suggested to play a role in neuronal growth, however, its role in peripheral nerve repair was not studied. The aim of this study was to examine the role of APP overexpression in peripheral nerve regeneration and neuropathic pain-related behavior in mice. Sciatic nerves of APP overexpressing and FVB/N wild-type mice were transected and immediately resutured. Evaluation of motor and sensory function and autotomy was carried out during 4-week follow up. We found no autotomy behavior as well as less significant atrophy of denervated muscles in APP overexpressing animals when compared to wild-type ones. Sciatic nerve function index outcome did not differ between groups. Histological evaluation revealed that the intensity of regeneration features, including GAP-43-positive growth cones and Schwann cells number in the distal stump of the transected nerve, was also similar in both groups. However, the regenerating fibers were organized more chaotically in wild-type mice and neuromas were much more often seen in this group. The number of macrophages infiltrating the injury site was significantly higher in control group. The number of surviving motoneurons was higher in transgenic mice than in control animals. Taken together, our findings suggest that APP overexpression is beneficial for nerve regeneration processes due to better organization of regenerating fibers, increased survival of motoneurons after autotomy and prevention of neuropathic pain. Copyright 2009 Elsevier Inc. All rights reserved.

Extracellular pH monitoring for use in closed-loop vagus nerve stimulation

Science.gov (United States)

Cork, Simon C.; Eftekhar, Amir; Mirza, Khalid B.; Zuliani, Claudio; Nikolic, Konstantin; Gardiner, James V.; Bloom, Stephen R.; Toumazou, Christofer

2018-02-01

Objective. Vagal nerve stimulation (VNS) has shown potential benefits for obesity treatment; however, current devices lack physiological feedback, which limit their efficacy. Changes in extracellular pH (pHe) have shown to be correlated with neural activity, but have traditionally been measured with glass microelectrodes, which limit their in vivo applicability. Approach. Iridium oxide has previously been shown to be sensitive to fluctuations in pH and is biocompatible. Iridium oxide microelectrodes were inserted into the subdiaphragmatic vagus nerve of anaesthetised rats. Introduction of the gut hormone cholecystokinin (CCK) or distension of the stomach was used to elicit vagal nerve activity. Main results. Iridium oxide microelectrodes have sufficient pH sensitivity to readily detect changes in pHe associated with both CCK and gastric distension. Furthermore, a custom-made Matlab script was able to use these changes in pHe to automatically trigger an implanted VNS device. Significance. This is the first study to show pHe changes in peripheral nerves in vivo. In addition, the demonstration that iridium oxide microelectrodes are sufficiently pH sensitive as to measure changes in pHe associated with physiological stimuli means they have the potential to be integrated into closed-loop neurostimulating devices.

Evidence of peripheral nerve blocks for cancer-related pain

DEFF Research Database (Denmark)

Klepstad, P; Kurita, G P; Mercadante, S

2015-01-01

The European Association for Palliative Care has initiated a comprehensive program to achieve an over-all review of the evidence of multiple cancer pain management strategies in order to extend the current guideline for treatment of cancer pain. The present systematic review analyzed the existing...... evidence of analgesic efficacy for peripheral nerve blocks in adult patients with cancer. A search strategy was elaborated with words related to cancer, pain, peripheral nerve and block. The search was performed in PubMed, EMBASE, and Cochrane for the period until February 2014. The number of abstracts...... retrieved was 155. No controlled studies were identified. Sixteen papers presented a total of 79 cases. The blocks applied were paravertebral blocks (10 cases), blocks in the head region (2 cases), plexus blocks (13 cases), intercostal blocks (43 cases) and others (11 cases). In general, most cases reported...

Evaluation and use of regenerative multi electrode interfaces in peripheral nerves

Science.gov (United States)

Desai, Vidhi

Peripheral nerves offer unique accessibility to the innate motor and sensory pathways that can be interfaced with high degree of selectivity for intuitive and bidirectional control of advanced upper extremity prosthetic limbs. Several peripheral nerve interfaces have been proposed and investigated over the last few decades with significant progress made in the area of sensory feedback. However, clinical translation still remains a formidable challenge due to the lack of long term recordings. Prominent causes include signal degradation, eventual interface failures, and lack of specificity in the low amplitude nerve signals. This dissertation evaluates the capabilities of the newly developed Regenerative Multi-electrode Interface (REMI) by the characterization of signal quality progression, the identification of interfaced axon types, and the demonstration of "functional linkage" between acquired signals and target organs. Chapter 2 details the chronic recording of high quality signals from REMI in sciatic nerve which remained stable over a 120 day implantation period indicative of minimal ongoing tissue response with no detrimental effects on the recording ability. The dominant cause of failures was attributable to abiotic factors pertaining to the connector/wire breakage, observed in 76% of REMI implants. Also, the REMI implants had 20% higher success rate and significantly larger Signal to Noise Ratio (SNR) in comparison to the Utah Slanted Electrode Array (USEA). Chapter 3 describes the successful feasibility of interfacing with motor and sensory axons by REMI implantation in the tibial and sural fascicles of the sciatic nerve. A characteristic sampling bias towards recording signals from medium-to-large diameter axons that are primarily involved in mechanoception and proprioception sensory functions was uncovered. Specific bursting units (Inter Spike Interval of 30-70ms) were observed most frequently from the tibial fascicle during bipedal locomotion. Chapter 4

Novel drug delivering conduit for peripheral nerve regeneration

Science.gov (United States)

Labroo, Pratima; Shea, Jill; Edwards, Kyle; Ho, Scott; Davis, Brett; Sant, Himanshu; Goodwin, Isak; Gale, Bruce; Agarwal, Jay

2017-12-01

Objective. This paper describes the design of a novel drug delivery apparatus integrated with a poly lactic-co-glycolic acid (PLGA) based nerve guide conduit for controlled local delivery of nerve growth factor (NGF) and application in peripheral nerve gap injury. Approach. An NGF dosage curve was acquired to determine the minimum in vitro concentration for optimal neurite outgrowth of dorsal root ganglion (DRG) cells; PLGA based drug delivery devices were then designed and tested in vitro and in vivo across 15 mm rat sciatic nerve gap injury model. Main results. The drug delivery nerve guide was able to release NGF for 28 d at concentrations (0.1-10 ng ml-1) that were shown to enhance DRG neurite growth. Furthermore, the released NGF was bioactive and able to enhance DRG neurite growth. Following these tests, optimized NGF-releasing nerve conduits were implanted across 15 mm sciatic nerve gaps in a rat model, where they demonstrated significant myelination and muscle innervation in vivo as compared to empty nerve conduits (p  design process and provides increased versatility for releasing a variety of different growth factors. This innovative device has the potential for broad applicability and allows for easier customization to change the type of drugs and dosage of individual drugs without devising a completely new biomaterial-drug conjugate each time.

Accuracy and complications of CT-guided core needle biopsy of peripheral nerve sheath tumours

Energy Technology Data Exchange (ETDEWEB)

Pianta, Marcus; Chock, Eric; Schlicht, Stephen [St Vincent' s Hospital, Fitzroy, VIC (Australia); McCombe, David [St Vincent' s Hospital and Victorian Hand Surgery Associates, Victoria (Australia)

2015-09-15

This single-centre study retrospectively reviews the complications in patients that have occurred following peripheral nerve sheath tumour biopsy, and assesses whether there is an association with biopsy technique or underlying lesion characteristics. 41 consecutive core needle biopsies of proven peripheral nerve sheath tumours over a 2-year period in a tertiary teaching hospital were reviewed. Patient demographics and symptoms, tumour characteristics and radiological appearances were recorded. Biopsy and surgical histology were correlated, and post-biopsy and surgical complications analyzed. 41 biopsies were performed in 38 patients. 68 % schwannomas, 24 % neurofibromas and 7 % malignant peripheral nerve sheath tumours. Biopsy histology correlated with surgery in all cases. 71 % of lesions were surgically excised. 60 % of patients reported pain related to their lesion. Following the biopsy, 12 % reported increased pain, which resolved in all cases. Pain exacerbation was noted in tumours smaller in size, more superficial and in closer proximity of the biopsy needle tip to the traversing nerve. Number of biopsy needle passes was not associated with an increased incidence of procedure-related pain. Core biopsy of a suspected peripheral nerve sheath tumour may be performed safely before excisional surgery to confirm lesion histology and assist prognosis. There is excellent correlation between core biopsy and excised surgical specimen histology. The most common complication of pain exacerbation is seen in a minority and is temporary, and more likely with smaller, more superficial lesions and a closer needle-tip to traversing nerve distance during biopsy. (orig.)

Accuracy and complications of CT-guided core needle biopsy of peripheral nerve sheath tumours

International Nuclear Information System (INIS)

Pianta, Marcus; Chock, Eric; Schlicht, Stephen; McCombe, David

2015-01-01

This single-centre study retrospectively reviews the complications in patients that have occurred following peripheral nerve sheath tumour biopsy, and assesses whether there is an association with biopsy technique or underlying lesion characteristics. 41 consecutive core needle biopsies of proven peripheral nerve sheath tumours over a 2-year period in a tertiary teaching hospital were reviewed. Patient demographics and symptoms, tumour characteristics and radiological appearances were recorded. Biopsy and surgical histology were correlated, and post-biopsy and surgical complications analyzed. 41 biopsies were performed in 38 patients. 68 % schwannomas, 24 % neurofibromas and 7 % malignant peripheral nerve sheath tumours. Biopsy histology correlated with surgery in all cases. 71 % of lesions were surgically excised. 60 % of patients reported pain related to their lesion. Following the biopsy, 12 % reported increased pain, which resolved in all cases. Pain exacerbation was noted in tumours smaller in size, more superficial and in closer proximity of the biopsy needle tip to the traversing nerve. Number of biopsy needle passes was not associated with an increased incidence of procedure-related pain. Core biopsy of a suspected peripheral nerve sheath tumour may be performed safely before excisional surgery to confirm lesion histology and assist prognosis. There is excellent correlation between core biopsy and excised surgical specimen histology. The most common complication of pain exacerbation is seen in a minority and is temporary, and more likely with smaller, more superficial lesions and a closer needle-tip to traversing nerve distance during biopsy. (orig.)

Establishment of Peripheral Nerve Injury Data Repository to Monitor and Support Population Health Decisions

Science.gov (United States)

2017-07-01

Military Medical Center (WRNMMC) for Peripheral Nerve Injury (PNI) treatment. A database , the Peripheral Nerve Injury Database (PNIDB), will be established...to catalog and describe the characteristics, mechanisms, management, and outcomes of PNIs using both retrospective chart review and prospective...decisions for patients with PNIs. These outcomes could be used in future study to further characterize PNIs and delineate which management

Effects of autonomic nerve stimulation on colorectal motility in rats

Science.gov (United States)

Tong, Wei Dong; Ridolfi, Timothy J.; Kosinski, Lauren; Ludwig, Kirk; Takahashi, Toku

2010-01-01

Background Several disease processes of the colon and rectum, including constipation and incontinence, have been associated with abnormalities of the autonomic nervous system. However, the autonomic innervation to the colon and rectum are not fully understood. The aims of this study were to investigate the effect of stimulation of vagus nerves, pelvic nerves (PN) and hypogastric nerves (HGN) on colorectal motility in rats. Methods Four strain gauge transducers were implanted on the proximal colon, mid colon, distal colon and rectum to record circular muscle contractions in rats. Electrical stimulation was administered to the efferent distal ends of the cervical vagus nerve, PN and HGN. Motility index (MI) was evaluated before and during stimulation. Key Results Electrical stimulation (5–20 Hz) of the cervical vagus elicited significant contractions in the mid colon and distal colon, whereas less pronounced contractions were observed in the proximal colon. PN stimulation elicited significant contractions in the rectum as well as the mid colon and distal colon. Atropine treatment almost completely abolished the contractions induced by vagus nerve and PN stimulation. HGN stimulation caused relaxations in the rectum, mid colon and distal colon. The relaxations in response to HGN stimulation were abolished by propranolol. Conclusions & Inferences Vagal innervation extends to the distal colon, while the PN has projections in the distribution of the rectum through the mid colon. This suggests a pattern of dual parasympathetic innervation in the left colon. Parasympathetic fibers regulate colorectal contractions via muscarinic receptors. The HGN mainly regulates colorectal relaxations via beta-adrenoceptors. PMID:20067587

Evaluation of Bcl-2, Bcl-x and Cleaved Caspase-3 in Malignant Peripheral Nerve Sheath Tumors and Neurofibromas

Directory of Open Access Journals (Sweden)

KARIN S. CUNHA

2013-11-01

Full Text Available AIMS: To study the expression of Bcl-2, Bcl-x, as well the presence of cleaved caspase-3 in neurofibromas and malignant peripheral nerve sheath tumors. The expression of Bcl-2 and Bcl-x and the presence of cleaved caspase 3 were compared to clinicopathological features of malignant peripheral nerve sheath tumors and their impact on survival rates were also investigated. MATERIALS AND METHODS: The evaluation of Bcl-2, Bcl-x and cleaved caspase-3 was performed by immunohistochemistry using tissue microarrays in 28 malignant peripheral nerve sheath tumors and 38 neurofibromas. Immunoquantification was performed by computerized digital image analysis. CONCLUSIONS: Apoptosis is altered in neurofibromas and mainly in malignant peripheral nerve sheath tumors. High levels of cleaved caspase-3 are more common in tumors with more aggressive histological features and it is associated with lower disease free survival of patients with malignant peripheral nerve sheath tumors.

Remodeling of peripheral nerve ensheathment during the larval-to-adult transition in Drosophila.

Science.gov (United States)

Subramanian, Aswati; Siefert, Matthew; Banerjee, Soumya; Vishal, Kumar; Bergmann, Kayla A; Curts, Clay C M; Dorr, Meredith; Molina, Camillo; Fernandes, Joyce

2017-10-01

Over the course of a 4-day period of metamorphosis, the Drosophila larval nervous system is remodeled to prepare for adult-specific behaviors. One example is the reorganization of peripheral nerves in the abdomen, where five pairs of abdominal nerves (A4-A8) fuse to form the terminal nerve trunk. This reorganization is associated with selective remodeling of four layers that ensheath each peripheral nerve. The neural lamella (NL), is the first to dismantle; its breakdown is initiated by 6 hours after puparium formation, and is completely removed by the end of the first day. This layer begins to re-appear on the third day of metamorphosis. Perineurial glial (PG) cells situated just underneath the NL, undergo significant proliferation on the first day of metamorphosis, and at that stage contribute to 95% of the glial cell population. Cells of the two inner layers, Sub-Perineurial Glia (SPG) and Wrapping Glia (WG) increase in number on the second half of metamorphosis. Induction of cell death in perineurial glia via the cell death gene reaper and the Diptheria toxin (DT-1) gene, results in abnormal bundling of the peripheral nerves, suggesting that perineurial glial cells play a role in the process. A significant number of animals fail to eclose in both reaper and DT-1 targeted animals, suggesting that disruption of PG also impacts eclosion behavior. The studies will help to establish the groundwork for further work on cellular and molecular processes that underlie the co-ordinated remodeling of glia and the peripheral nerves they ensheath. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1144-1160, 2017. © 2017 Wiley Periodicals, Inc.

Multi-microelectrode devices for intrafascicular use in peripheral nerve

NARCIS (Netherlands)

Rutten, Wim

1996-01-01

This minisymposium paper gives an overview of experimental, modeling, design and microfabrication steps which lead towards the University of Twente three-dimensional 128-fold silicon microelectrode device. The device is meant for implantation in peripheral nerve for neuromuscular control purposes

Studies of peripheral sensory nerves in paclitaxel-induced painful peripheral neuropathy: Evidence for mitochondrial dysfunction

OpenAIRE

Flatters, Sarah J.L.; Bennett, Gary J.

2006-01-01

Paclitaxel chemotherapy frequently induces neuropathic pain during and often persisting after therapy. The mechanisms responsible for this pain are unknown. Using a rat model of paclitaxel-induced painful peripheral neuropathy, we have performed studies to search for peripheral nerve pathology. Paclitaxel-induced mechano-allodynia and mechano-hyperalgesia were evident after a short delay, peaked at day 27 and finally resolved on day 155. Paclitaxel- and vehicle-treated rats were perfused on d...

Muscle potentials evoked by magnetic stimulation of the sciatic nerve in unilateral sciatic nerve dysfunction

NARCIS (Netherlands)

Van Soens, I.; Struys, M. M. R. F.; Van Ham, L. M. L.

Magnetic stimulation of the sciatic nerve and subsequent recording of the muscle-evoked potential (MEP) was performed in eight dogs and three cats with unilateral sciatic nerve dysfunction. Localisation of the lesion in the sciatic nerve was based on the history, clinical neurological examination

Hericium erinaceus (Bull.: Fr.) Pers., a medicinal mushroom, activates peripheral nerve regeneration.

Science.gov (United States)

Wong, Kah-Hui; Kanagasabapathy, Gowri; Naidu, Murali; David, Pamela; Sabaratnam, Vikineswary

2016-10-01

To study the ability of aqueous extract of Hericium erinaceus mushroom in the treatment of nerve injury following peroneal nerve crush in Sprague-Dawley rats. Aqueous extract of Hericium erinaceus was given by daily oral administration following peroneal nerve crush injury in Sprague-Dawley rats. The expression of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways; and c-Jun and c-Fos genes were studied in dorsal root ganglia (DRG) whereas the activity of protein synthesis was assessed in peroneal nerves by immunohistochemical method. Peripheral nerve injury leads to changes at the axonal site of injury and remotely located DRG containing cell bodies of sensory afferent neurons. Immunofluorescence studies showed that DRG neurons ipsilateral to the crush injury in rats of treated groups expressed higher immunoreactivities for Akt, MAPK, c-Jun and c-Fos as compared with negative control group (P <0.05). The intensity of nuclear ribonucleoprotein in the distal segments of crushed nerves of treated groups was significantly higher than in the negative control group (P <0.05). H. erinaceus is capable of promoting peripheral nerve regeneration after injury. Potential signaling pathways include Akt, MAPK, c-Jun, and c-Fos, and protein synthesis have been shown to be involved in its action.

Sensory and Motor Peripheral Nerve Function and Longitudinal Changes in Quadriceps Strength

DEFF Research Database (Denmark)

Ward, R. E.; Boudreau, R. M.; Caserotti, P.

2015-01-01

Background. Poor peripheral nerve function is common in older adults and may be a risk factor for strength decline, although this has not been assessed longitudinally. Methods. We assessed whether sensorimotor peripheral nerve function predicts strength longitudinally in 1,830 participants (age...... was assessed with 10-g and 1.4-g monofilaments and average vibration detection threshold at the toe. Lower-extremity neuropathy symptoms were self-reported. Results. Worse vibration detection threshold predicted 2.4% lower strength in men and worse motor amplitude and two symptoms predicted 2.5% and 8.1% lower...

Regulation of semaphorin III/collapsin-1 gene expression during peripheral nerve regeneration

NARCIS (Netherlands)

Pasterkamp, R Jeroen; Giger, Roman J; Verhaagen, J

1998-01-01

The competence of neurons to regenerate depends on their ability to initiate a program of gene expression supporting growth and on the growth-permissive properties of glial cells in the distal stump of the injured nerve. Most studies on intrinsic molecular mechanisms governing peripheral nerve

A study of tapping by the unaffected finger of patients presenting with central and peripheral nerve damage.

Science.gov (United States)

Zhang, Lingli; Han, Xiuying; Li, Peihong; Liu, Yang; Zhu, Yulian; Zou, Jun; Yu, Zhusheng

2015-01-01

Whether the unaffected function of the hand of patients presenting with nerve injury is affected remains inconclusive. We aimed to evaluate whether there are differences in finger tapping following central or peripheral nerve injury compared with the unaffected hand and the ipsilateral hand of a healthy subject. Thirty right brain stroke patients with hemiplegia, 30 left arm peripheral nerve injury cases, and 60 healthy people were selected. We tested finger tapping of the right hands, and each subject performed the test twice. Finger tapping following peripheral nerve injury as compared with the unaffected hand and the dominant hand of a healthy person was markedly higher than was found for central nerve injury (P tapping of the male peripheral group's unaffected hand and the control group's dominant hand was significantly higher than the central group (P tapping of the female control group's dominant hand was significantly higher than the central group's unaffected hand (P < 0.01, P = 0.002), the peripheral group's unaffected hand (P < 0.05, P = 0.034). The unaffected function of the hand of patients with central and peripheral nerve injury was different as compared with the ipsilateral hand of healthy individuals. The rehabilitation therapist should intensify the practice of normal upper limb fine activities and coordination of the patient.

Myelination and nodal formation of regenerated peripheral nerve fibers following transplantation of acutely prepared olfactory ensheathing cells

Science.gov (United States)

Dombrowski, Mary A.; Sasaki, Masanori; Lankford, Karen L.; Kocsis, Jeffery D.; Radtke, Christine

2009-01-01

Transplantation of olfactory ensheathing cells (OECs) into injured spinal cord results in improved functional outcome. Mechanisms suggested to account for this functional improvement include axonal regeneration, remyelination and neuroprotection. OECs transplanted into transected peripheral nerve have been shown to modify peripheral axonal regeneration and functional outcome. However, little is known of the detailed integration of OECs at the transplantation site in peripheral nerve. To address this issue cells populations enriched in OECs were isolated from the olfactory bulbs of adult green fluorescent protein (GFP)-expressing transgenic rats and transplanted into a sciatic nerve crush lesion which transects all axons. Five weeks to six months after transplantation the nerves were studied histologically. GFP-expressing OECs survived in the lesion and distributed longitudinally across the lesion zone. The internodal regions of individual teased fibers distal to the transection site were characterized by GFP expression in the cytoplasmic and nuclear compartments of cells surrounding the axons. Immuno-electron microscopy for GFP indicated that the transplanted OECs formed peripheral type myelin. Immunostaining for sodium channel and Caspr revealed a high density of Nav1.6 at the newly formed nodes of Ranvier which were flanked by paranodal Caspr staining. These results indicate that transplanted OECs extensively integrate into transected peripheral nerve and form myelin on regenerated peripheral nerve fibers, and that nodes of Ranvier of these axons display proper sodium channel organization. PMID:17112480

A Study of Tapping by the Unaffected Finger of Patients Presenting with Central and Peripheral Nerve Damage

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Lingli eZhang

2015-05-01

Full Text Available Aim: Whether the unaffected function of the hand of patients presenting with nerve injury is affected remains inconclusive. We aimed to evaluate whether there are differences in finger tapping following central or peripheral nerve injury compared with the unaffected hand and the ipsilateral hand of a healthy subject.Methods: 30 right brain stroke patients with hemiplegia, 30 left arm peripheral nerve injury cases and 60 healthy people were selected. We tested finger tapping of the right hands, and each subject performed the test twice.Results: Finger tapping following peripheral nerve injury as compared with the unaffected hand and the dominant hand of a healthy person was significantly higher than was found for central nerve injury (P<0.05. Finger tapping of the male peripheral group’s unaffected hand and the control group’s dominant hand was significantly higher than the central group (P<0.001. However, finger tapping of the female control group’s dominant hand was markedly higher than the central group’s unaffected hand (P<0.01, P=0.002, the peripheral group’s unaffected hand (P<0.05, P=0.034. Conclusion: The unaffected function of the hand of patients with central and peripheral nerve injury was different as compared with the ipsilateral hand of healthy individuals. The rehabilitation therapist should intensify the practice of normal upper limb fine activities and coordination of the patient.

Trends in the design of nerve guidance channels in peripheral nerve tissue engineering.

Science.gov (United States)

Chiono, Valeria; Tonda-Turo, Chiara

2015-08-01

The current trend of peripheral nerve tissue engineering is the design of advanced nerve guidance channels (NGCs) acting as physical guidance for regeneration of nerves across lesions. NGCs should present multifunctional properties aiming to direct the sprouting of axons from the proximal nerve end, to concentrate growth factors secreted by the injured nerve ends, and to reduce the ingrowth of scar tissue into the injury site. A critical aspect in the design of NGCs is conferring them the ability to provide topographic, chemotactic and haptotactic cues that lead to functional nerve regeneration thus increasing the axon growth rate and avoiding or minimizing end-organ (e.g. muscle) atrophy. The present work reviews the recent state of the art in NGCs engineering and defines the external guide and internal fillers structural and compositional requirements that should be satisfied to improve nerve regeneration, especially in the case of large gaps (>2 cm). Techniques for NGCs fabrication were described highlighting the innovative approaches direct to enhance the regeneration of axon stumps compared to current clinical treatments. Furthermore, the possibility to apply stem cells as internal cues to the NGCs was discussed focusing on scaffold properties necessary to ensure cell survival. Finally, the optimized features for NGCs design were summarized showing as multifunctional cues are needed to produce NGCs having improved results in clinics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Peripheral nerve injury induces glial activation in primary motor cortex

OpenAIRE

Julieta Troncoso; Julieta Troncoso; Efraín Buriticá; Efraín Buriticá

2015-01-01

Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to eithe...

Injection Pressure as a Marker of Intraneural Injection in Procedures of Peripheral Nerves Blockade

Directory of Open Access Journals (Sweden)

Ilvana Vučković

2006-11-01

Full Text Available The blockade of peripheral nerves carries a certain risk of unwanted complications, which can follow after unintentional intraneural injection of a local anesthetic. Up till today, the research of measuring injection pressure has been based on animal models, even though the histological structure of periphery nerve is different for animal and human population, so the application pressure which presages intraneural injection in human population is still unknown. As material in performing this study there have been used 12 Wistar rats and 12 delivered stillborns. After bilateral access to the median nerve, we applied 3 ml of 2% lidocaine with epinephrine, with the help of automatic syringe charger. The needle was at first placed perineural on one side, and then intraneural on the other side of both examination groups. During every application the pressure values were monitored using the manometer, and then they were analyzed by special software program BioBench. All perineural injections resulted with the pressure < or = 27.92 kPa, while the majority of intraneural injections were combined with the injectionpressure > or = 69.8 kPa. The difference between intraneural and perineural injection pressures for the two different examination groups (rats and delivered stillborns was not statistically significant (P>0.05. As prevention from intraneural injections today are in use two methods: the method of causing paresthesia or the method of using the peripheral nerve stimulator. However the nerve injury can still occur, independent from the technique used. If our results are used in clinical practice on human population, than the high injection pressure could be the markerof intraneural lodging of a needle.

Magnetic resonance imaging research progress on brain functional reorganization after peripheral nerve injury

International Nuclear Information System (INIS)

Wang Weiwei; Liu Hanqiu

2013-01-01

In the recent years, with the development of functional magnetic resonance imaging technology the brain plasticity and functional reorganization are hot topics in the central nervous system imaging studies. Brain functional reorganization and rehabilitation after peripheral nerve injury may have certain regularity. In this paper, the progress of brain functional magnetic resonance imaging technology and its applications in the world wide clinical and experimental researches of the brain functional reorganization after peripheral nerve injury is are reviewed. (authors)

Effect of Surface Pore Structure of Nerve Guide Conduit on Peripheral Nerve Regeneration

Science.gov (United States)

Oh, Se Heang; Kim, Jin Rae; Kwon, Gu Birm; Namgung, Uk; Song, Kyu Sang

2013-01-01

Polycaprolactone (PCL)/Pluronic F127 nerve guide conduits (NGCs) with different surface pore structures (nano-porous inner surface vs. micro-porous inner surface) but similar physical and chemical properties were fabricated by rolling the opposite side of asymmetrically porous PCL/F127 membranes. The effect of the pore structure on peripheral nerve regeneration through the NGCs was investigated using a sciatic nerve defect model of rats. The nerve fibers and tissues were shown to have regenerated along the longitudinal direction through the NGC with a nano-porous inner surface (Nanopore NGC), while they grew toward the porous wall of the NGC with a micro-porous inner surface (Micropore NGC) and, thus, their growth was restricted when compared with the Nanopore NGC, as investigated by immunohistochemical evaluations (by fluorescence microscopy with anti-neurofilament staining and Hoechst staining for growth pattern of nerve fibers), histological evaluations (by light microscopy with Meyer's modified trichrome staining and Toluidine blue staining and transmission electron microscopy for the regeneration of axon and myelin sheath), and FluoroGold retrograde tracing (for reconnection between proximal and distal stumps). The effect of nerve growth factor (NGF) immobilized on the pore surfaces of the NGCs on nerve regeneration was not so significant when compared with NGCs not containing immobilized NGF. The NGC system with different surface pore structures but the same chemical/physical properties seems to be a good tool that is used for elucidating the surface pore effect of NGCs on nerve regeneration. PMID:22871377

Differential induction of c-Fos and phosphorylated ERK by a noxious stimulus after peripheral nerve injury.

Science.gov (United States)

Tabata, Mitsuyasu; Terayama, Ryuji; Maruhama, Kotaro; Iida, Seiji; Sugimoto, Tomosada

2018-03-01

In this study, we compared induction of c-Fos and phosphorylated extracellular signal-regulated kinase (p-ERK) in the spinal dorsal horn after peripheral nerve injury. We examined the spinal dorsal horn for noxious heat-induced c-Fos and p-ERK protein-like immunoreactive (c-Fos- and p-ERK-IR) neuron profiles after tibial nerve injury. The effect of administration of a MEK 1/2 inhibitor (PD98059) on noxious heat-induced c-Fos expression was also examined after tibial nerve injury. A large number of c-Fos- and p-ERK-IR neuron profiles were induced by noxious heat stimulation to the hindpaw in sham-operated animals. A marked reduction in the number of c-Fos- and p-ERK-IR neuron profiles was observed in the medial 1/3 (tibial territory) of the dorsal horn at 3 and 7 days after nerve injury. Although c-Fos-IR neuron profiles had reappeared by 14 days after injury, the number of p-ERK-IR neuron profiles remained decreased in the tibial territory of the superficial dorsal horn. Double immunofluorescence labeling for c-Fos and p-ERK induced by noxious heat stimulation to the hindpaw at different time points revealed that a large number of c-Fos-IR, but not p-ERK-IR, neuron profiles were distributed in the tibial territory after injury. Although administration of a MEK 1/2 inhibitor to the spinal cord suppressed noxious heat-induced c-Fos expression in the peroneal territory, this treatment did not alter c-Fos induction in the tibial territory after nerve injury. ERK phosphorylation may be involved in c-Fos induction in normal nociceptive responses, but not in exaggerated c-Fos induction after nerve injury.

Arterial and venous plasma levels of bupivacaine following peripheral nerve blocks.

Science.gov (United States)

Moore, D C; Mather, L E; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G

1976-01-01

Mean arterial plasma (MAP) and peripheral mean venous plasma (MVP) levels of bupivacaine were ascertained in 3 groups of 10 patients each for: (1) intercostal nerve block, 400 mg; (2) block of the sciatic, femoral, and lateral femoral cutaneous nerves, with or without block of the obturator nerve, 400 mg; and (3) supraclavicular brachial plexus block, 300 mg. MAP levels were consistently higher than simultaneously sampled MVP levels, the highest levels occurring from bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine has a much wider margin of safety in humans than is now stated.

Matching of motor-sensory modality in the rodent femoral nerve model shows no enhanced effect on peripheral nerve regeneration

Science.gov (United States)

Kawamura, David H.; Johnson, Philip J.; Moore, Amy M.; Magill, Christina K.; Hunter, Daniel A.; Ray, Wilson Z.; Tung, Thomas HH.; Mackinnon, Susan E.

2010-01-01

The treatment of peripheral nerve injuries with nerve gaps largely consists of autologous nerve grafting utilizing sensory nerve donors. Underlying this clinical practice is the assumption that sensory autografts provide a suitable substrate for motoneuron regeneration, thereby facilitating motor endplate reinnervation and functional recovery. This study examined the role of nerve graft modality on axonal regeneration, comparing motor nerve regeneration through motor, sensory, and mixed nerve isografts in the Lewis rat. A total of 100 rats underwent grafting of the motor or sensory branch of the femoral nerve with histomorphometric analysis performed after 5, 6, or 7 weeks. Analysis demonstrated similar nerve regeneration in motor, sensory, and mixed nerve grafts at all three time points. These data indicate that matching of motor-sensory modality in the rat femoral nerve does not confer improved axonal regeneration through nerve isografts. PMID:20122927

Photocrosslinkable Gelatin/Tropoelastin Hydrogel Adhesives for Peripheral Nerve Repair.

Science.gov (United States)

Soucy, Jonathan R; Shirzaei Sani, Ehsan; Portillo Lara, Roberto; Diaz, David; Dias, Felipe; Weiss, Anthony S; Koppes, Abigail N; Koppes, Ryan A; Annabi, Nasim

2018-05-09

Suturing peripheral nerve transections is the predominant therapeutic strategy for nerve repair. However, the use of sutures leads to scar tissue formation, hinders nerve regeneration, and prevents functional recovery. Fibrin-based adhesives have been widely used for nerve reconstruction, but their limited adhesive and mechanical strength and inability to promote nerve regeneration hamper their utility as a stand-alone intervention. To overcome these challenges, we engineered composite hydrogels that are neurosupportive and possess strong tissue adhesion. These composites were synthesized by photocrosslinking two naturally derived polymers, gelatin-methacryloyl (GelMA) and methacryloyl-substituted tropoelastin (MeTro). The engineered materials exhibited tunable mechanical properties by varying the GelMA/MeTro ratio. In addition, GelMA/MeTro hydrogels exhibited 15-fold higher adhesive strength to nerve tissue ex vivo compared to fibrin control. Furthermore, the composites were shown to support Schwann cell (SC) viability and proliferation, as well as neurite extension and glial cell participation in vitro, which are essential cellular components for nerve regeneration. Finally, subcutaneously implanted GelMA/MeTro hydrogels exhibited slower degradation in vivo compared with pure GelMA, indicating its potential to support the growth of slowly regenerating nerves. Thus, GelMA/MeTro composites may be used as clinically relevant biomaterials to regenerate nerves and reduce the need for microsurgical suturing during nerve reconstruction.

Using Arrays of Microelectrodes Implanted in Residual Peripheral Nerves to Provide Dextrous Control of, and Modulated Sensory Feedback from, a Hand Prosthesis

Science.gov (United States)

2015-10-01

extended that work by investigating multiple aspects important for developing future bidirectional neural prostheses based on high-count microelectrode...Fan J M, Kao J C, Stavisky S D, Ryu S and Shenoy K 2012 A recurrent neural network for closed-loop intracortical brain-machine interface decoders J...Peripheral Nerve Interface, Prosthetic Hand, Neural Prosthesis, Sensory Feedback, Micro-stimulation, Electrophysiology, Action Potentials, Micro

Vagus nerve stimulation and stereotactic radiosurgery

International Nuclear Information System (INIS)

Kawai, Kensuke

2005-01-01

Vagus nerve stimulation and stereotactic radiosurgery represent novel and less invasive therapeutics for medically intractable epilepsy. Chronic stimulation of the left vagus nerve with implanted generator and electrodes inhibits seizure susceptibility of the cerebral cortices. While the underlying mechanisms of the effect remains to be further elucidated, the efficacy and safety of vagus nerve stimulation have been established by randomized clinical trials in the United States and European countries. It has been widely accepted as a treatment option for patients with medically intractable epilepsy and for whom brain surgery is not indicated. The primary indication of vagus nerve stimulation in the clinical trials was localization-related epilepsy in adult patients but efficacy in a wide range of patient groups such as generalized epilepsy and children has been reported. Improvements in daytime alertness, mood, higher cognitive functions and overall quality of life have been reported other than the effect on epileptic seizures. Since the devices are not approved for clinical use in Japan by the Health, Labor and Welfare Ministry, there exist barriers to provide this treatment to patients at present. Stereotactic radiosurgery has been used for temporal lobe epilepsy and hypothalamic hamartoma, but it is still controversial whether the therapy is more effective and less invasive than brain surgery. Promising results of gamma knife radiosurgery for medically intractable temporal lobe epilepsy with unilateral hippocampal sclerosis have been reported essentially from one French center. Results from others were not as favorable. There seems to be an unignorable risk of brain edema and radiation necrosis when the delivered dose over the medial temporal structures is high enough to abolish epileptic seizures. A randomized clinical trial comparing different marginal doses is ongoing in the United States. Clinical trials like this, technical advancement and standardization

Role of Demyelination Efficiency within Acellular Nerve Scaffolds during Nerve Regeneration across Peripheral Defects

Directory of Open Access Journals (Sweden)

Meiqin Cai

2017-01-01

Full Text Available Hudson’s optimized chemical processing method is the most commonly used chemical method to prepare acellular nerve scaffolds for the reconstruction of large peripheral nerve defects. However, residual myelin attached to the basal laminar tube has been observed in acellular nerve scaffolds prepared using Hudson’s method. Here, we describe a novel method of producing acellular nerve scaffolds that eliminates residual myelin more effectively than Hudson’s method through the use of various detergent combinations of sulfobetaine-10, sulfobetaine-16, Triton X-200, sodium deoxycholate, and peracetic acid. In addition, the efficacy of this new scaffold in repairing a 1.5 cm defect in the sciatic nerve of rats was examined. The modified method produced a higher degree of demyelination than Hudson’s method, resulting in a minor host immune response in vivo and providing an improved environment for nerve regeneration and, consequently, better functional recovery. A morphological study showed that the number of regenerated axons in the modified group and Hudson group did not differ. However, the autograft and modified groups were more similar in myelin sheath regeneration than the autograft and Hudson groups. These results suggest that the modified method for producing a demyelinated acellular scaffold may aid functional recovery in general after nerve defects.

[Damage to cranial and peripheral nerves following patency restoration of the internal carotid artery].

Science.gov (United States)

Myrcha, P; Ciostek, P; Szopiński, P; Noszczyk, W

2001-01-01

The aim of the study was an assessment of the incidence of injury to cranial and peripheral nerves as complication of patency restoration of the internal carotid artery, and analysis of the effect of peripheral nerve injury on the results of carotid patency restoration. From Oct 1987 to Sept 1999 543 procedures were carried out for restoration of patency of the internal carotid artery. After the operation hypoglossus nerve injury was found in 7 cases (1.4%), vagus injury in 9 (1.8%). Signs of exclusively recurrent laryngeal nerve damage were found in 6 cases (1.2%). Glossopharyngeus nerve was damaged in 2 cases (0.4%), transient phrenic nerve palsy as a result of conduction anaesthesia was noted in 2 cases (0.4%). Damage to the transverse cervical nerve was found in 96 cases (60%). In 2 patients (1.2%) lower position of mouth angle was due to section of the mandibular ramus of the facial nerve. In another 2 cases skin sensation disturbances were a consequence of lesion of the auricularis magnus nerve and always they coexisted with signs of transverse cervical nerve damage. damage to the cranial nerves during operation for carotid patency restoration are frequent but mostly they are not connected with any health risks and often they regress spontaneously.

Review: peripheral nerve regeneration using non-tubular alginate gel crosslinked with covalent bonds.

Science.gov (United States)

Hashimoto, Tadashi; Suzuki, Yoshihisa; Suzuki, Kyoko; Nakashima, Toshihide; Tanihara, Masao; Ide, Chizuka

2005-06-01

We have developed a nerve regeneration material consisting of alginate gel crosslinked with covalent bonds. in the first part of this study, we attempted to analyze nerve regeneration through alginate gel in the early stages within 2 weeks. in the second part, we tried to regenerate cat peripheral nerve by using alginate tubular or non-tubular nerve regeneration devices, and compared their efficacies. Four days after surgery, regenerating axons grew without Schwann cell investment through the partially degraded alginate gel, being in direct contact with the alginate without a basal lamina covering. One to 2 weeks after surgery, regenerating axons were surrounded by common Schwann cells, forming small bundles, with some axons at the periphery being partly in direct contact with alginate. At the distal stump, numerous Schwann cells had migrated into the alginate 8-14 days after surgery. Remarkable restorations of the 50-mm gap in cat sciatic nerve were obtained after a long term by using tubular or non-tubular nerve regeneration material consisting mainly of alginate gel. However, there was no significant difference between both groups at electrophysiological and morphological evaluation. Although, nowadays, nerve regeneration materials being marketed mostly have a tubular structure, our results suggest that the tubular structure is not indispensable for peripheral nerve regeneration.

Direct Conversion of Human Fibroblasts into Schwann Cells that Facilitate Regeneration of Injured Peripheral Nerve In Vivo.

Science.gov (United States)

Sowa, Yoshihiro; Kishida, Tsunao; Tomita, Koichi; Yamamoto, Kenta; Numajiri, Toshiaki; Mazda, Osam

2017-04-01

Schwann cells (SCs) play pivotal roles in the maintenance and regeneration of the peripheral nervous system. Although transplantation of SCs enhances repair of experimentally damaged peripheral and central nerve tissues, it is difficult to prepare a sufficient number of functional SCs for transplantation therapy without causing adverse events for the donor. Here, we generated functional SCs by somatic cell reprogramming procedures and demonstrated their capability to promote peripheral nerve regeneration. Normal human fibroblasts were phenotypically converted into SCs by transducing SOX10 and Krox20 genes followed by culturing for 10 days resulting in approximately 43% directly converted Schwann cells (dSCs). The dSCs expressed SC-specific proteins, secreted neurotrophic factors, and induced neuronal cells to extend neurites. The dSCs also displayed myelin-forming capability both in vitro and in vivo. Moreover, transplantation of the dSCs into the transected sciatic nerve in mice resulted in significantly accelerated regeneration of the nerve and in improved motor function at a level comparable to that with transplantation of the SCs obtained from a peripheral nerve. The dSCs induced by our procedure may be applicable for novel regeneration therapy for not only peripheral nerve injury but also for central nerve damage and for neurodegenerative disorders related to SC dysfunction. Stem Cells Translational Medicine 2017;6:1207-1216. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Flexible multichannel vagus nerve electrode for stimulation and recording for heart failure treatment.

Science.gov (United States)

Xue, Ning; Martinez, Ignacio Delgado; Sun, Jianhai; Cheng, Yuhua; Liu, Chunxiu

2018-07-30

Vagus nerve stimulation is an emerging bioelectronic medicine to modulate cardiac function, as the nerve provides parasympathetic innervation to the heart. In this study, we developed a polyimide based 2D cuff electrode to wrap around on the vagus nerve. Thanks to the tiny size and bendable protruding structure of the contact tips of the device, the electrode sites are able to flexibly bend to touch the nerve, selectively record and stimulate the vagus nerve. Gold, platinum and platinum black materials were chosen to compose the electrodes for nerve stimulation and recording, respectively. Since the platinum black has ~30 times larger charge delivery capacity (CDC) than gold, Pt black electrode is used for nerve stimulation. The electrochemical impedance spectroscopy and cyclic voltammetry measurement of the three materials were conducted in vitro, revealing the results of 405 kΩ, 41 kΩ, 10.5 kΩ, @1 kHz and 0.81 mC/cm 2 , 4.26 mC/cm 2 , 25.5 mC/cm 2 , respectively (n = 3). The cuff electrodes were implanted into the right-sided vagus nerve of rats for in vivo experiment. Biphasic current configuration was implemented for nerve stimulation with frequency of 10 Hz, pulse during of 300 μs and various currents stimulus. The result shows the heart beat frequency drops up to 36% during the stimulation and was able to return the regular frequency as stimulation was removed. Subsequently, the vagus nerve signals were recorded with the four channel cuff electrodes. The magnitude of the compound nerve action potentials (CNAPs) is ~10 μV and the signal to noise ratio (SNR) is ~20. Copyright © 2018 Elsevier B.V. All rights reserved.

In Vitro Magnetic Resonance Imaging Evaluation of Fragmented, Open-Coil, Percutaneous Peripheral Nerve Stimulation Leads.

Science.gov (United States)

Shellock, Frank G; Zare, Armaan; Ilfeld, Brian M; Chae, John; Strother, Robert B

2018-04-01

Percutaneous peripheral nerve stimulation (PNS) is an FDA-cleared pain treatment. Occasionally, fragments of the lead (MicroLead, SPR Therapeutics, LLC, Cleveland, OH, USA) may be retained following lead removal. Since the lead is metallic, there are associated magnetic resonance imaging (MRI) risks. Therefore, the objective of this investigation was to evaluate MRI-related issues (i.e., magnetic field interactions, heating, and artifacts) for various lead fragments. Testing was conducted using standardized techniques on lead fragments of different lengths (i.e., 50, 75, and 100% of maximum possible fragment length of 12.7 cm) to determine MRI-related problems. Magnetic field interactions (i.e., translational attraction and torque) and artifacts were tested for the longest lead fragment at 3 Tesla. MRI-related heating was evaluated at 1.5 Tesla/64 MHz and 3 Tesla/128 MHz with each lead fragment placed in a gelled-saline filled phantom. Temperatures were recorded on the lead fragments while using relatively high RF power levels. Artifacts were evaluated using T1-weighted, spin echo, and gradient echo (GRE) pulse sequences. The longest lead fragment produced only minor magnetic field interactions. For the lead fragments evaluated, physiologically inconsequential MRI-related heating occurred at 1.5 Tesla/64 MHz while under certain 3 Tesla/128 MHz conditions, excessive temperature elevations may occur. Artifacts extended approximately 7 mm from the lead fragment on the GRE pulse sequence, suggesting that anatomy located at a position greater than this distance may be visualized on MRI. MRI may be performed safely in patients with retained lead fragments at 1.5 Tesla using the specific conditions of this study (i.e., MR Conditional). Due to possible excessive temperature rises at 3 Tesla, performing MRI at that field strength is currently inadvisable. © 2017 International Neuromodulation Society.

Deficiency of electroneutral K+-Cl- cotransporter 3 causes a disruption in impulse propagation along peripheral nerves.

Science.gov (United States)

Sun, Yuan-Ting; Lin, Thy-Sheng; Tzeng, Shun-Fen; Delpire, Eric; Shen, Meng-Ru

2010-10-01

Nerve conduction requires the fine tuning of ionic currents through delicate interactions between axons and Schwann cells. The K(+)-Cl(-) cotransporter (KCC) family includes four isoforms (KCC1-4) that play an important role in the maintenance of cellular osmotic homeostasis via the coupled electroneutral movement of K(+) and Cl(-) with concurrent water flux. Mutation in SLC12A6 gene encoding KCC3 results in an autosomal recessive disease, known as agenesis of the corpus callosum associated with peripheral neuropathy. Nevertheless, the role of KCC3 in nerve function remains a puzzle. In this study, the microscopic examination of KCC isoforms expressed in peripheral nerves showed high expression of KCC2-4 in nodal segments of the axons and in the perinucleus and microvilli of Schwann cells. The KCC inhibitor [[(dihydroindenyl)oxy]alkanoic acid] but not the Na(+)-K(+)-2Cl(-)-cotransport inhibitor (bumetanide) dose-dependently suppressed the amplitude and area of compound muscle action potential, indicating the involvement of KCC activity in peripheral nerve conduction. Furthermore, the amplitude and area under the curve were smaller, and the nerve conduction velocity was slower in nerves from KCC3(-/-) mice than in nerves from wild-type mice, while the expression pattern of KCC2 and KCC4 was similar in KCC3 kockout and wild-type strains. KCC3(-/-) mice also manifested a prominent motor deficit in the beam-walking test. This is the first study to demonstrate that the K(+)-Cl(-) cotransporter activity of KCC3 contributes to the propagation of action potentials along peripheral nerves. (c) 2010 Wiley-Liss, Inc.

Changes in the structural properties of peripheral nerves after transection.

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Toby, E B; Meyer, B M; Schwappach, J; Alvine, G

1996-11-01

Changes in peripheral nerve structural properties after transection were measured weekly for 5 weeks in the distal stump of the sciatic nerve in 50 Sprague-Dawley rats. Each week after transection, the distal stump of the transected nerve showed increased stiffness when compared to intact nerves. Linear elastic stiffness reached a maximum at weeks 1 and 2 after transection, when the transected nerves were 15% stiffer than the contralateral control sides. Toughness was also increased and reached a maximum at week 4 with a 50% difference between values for experimental and control sides. Overall failure load was between 21% and 27% greater, peaking at week 3. An increase in stiffness of the distal stump would result in increased tension at the suture line, as the nerve gap is overcome when performing a delayed neurorraphy. These data suggest, with respect to structural properties, that an end-to-end repair should be carried out at the time of injury; after only 1 week, significant stiffness in the distal segment of the nerve developed, which should result in an increase in tension at the repair site.

Peripheral Nerve Injuries and Transplantation of Olfactory Ensheathing Cells for Axonal Regeneration and Remyelination: Fact or Fiction?

Directory of Open Access Journals (Sweden)

Christine Radtke

2012-10-01

Full Text Available Successful nerve regeneration after nerve trauma is not only important for the restoration of motor and sensory functions, but also to reduce the potential for abnormal sensory impulse generation that can occur following neuroma formation. Satisfying functional results after severe lesions are difficult to achieve and the development of interventional methods to achieve optimal functional recovery after peripheral nerve injury is of increasing clinical interest. Olfactory ensheathing cells (OECs have been used to improve axonal regeneration and functional outcome in a number of studies in spinal cord injury models. The rationale is that the OECs may provide trophic support and a permissive environment for axonal regeneration. The experimental transplantation of OECs to support and enhance peripheral nerve regeneration is much more limited. This chapter reviews studies using OECs as an experimental cell therapy to improve peripheral nerve regeneration.

Nerve Regeneration Should Be Highly Valued in the Treatment of Diabetic Peripheral Neuropathy

Institute of Scientific and Technical Information of China (English)

LIANG Xiao-chun

2008-01-01

@@ Diabetic peripheral neuropathy (DPN) is the most common chronic complication of the long-term complications of diabetes, affecting up to 90% of patients during the progress of the disease. Many parts of the nerve system, including the sensory nerves, motor nerves and autonomic nerves, can be affected, leading to various clinical features. DPN leads not only to a great degree of mutilation and death but also to the occurrence and development of other long-term complications in diabetics.

Electrical stimulation of dog pudendal nerve regulates the excitatory pudendal-to-bladder reflex

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Yan-he Ju

2016-01-01

Full Text Available Pudendal nerve plays an important role in urine storage and voiding. Our hypothesis is that a neuroprosthetic device placed in the pudendal nerve trunk can modulate bladder function after suprasacral spinal cord injury. We had confirmed the inhibitory pudendal-to-bladder reflex by stimulating either the branch or the trunk of the pudendal nerve. This study explored the excitatory pudendal-to-bladder reflex in beagle dogs, with intact or injured spinal cord, by electrical stimulation of the pudendal nerve trunk. The optimal stimulation frequency was approximately 15-25 Hz. This excitatory effect was dependent to some extent on the bladder volume. We conclude that stimulation of the pudendal nerve trunk is a promising method to modulate bladder function.

In vitro assessment of TAT — Ciliary Neurotrophic Factor therapeutic potential for peripheral nerve regeneration

International Nuclear Information System (INIS)

Barbon, Silvia; Stocco, Elena; Negro, Alessandro; Dalzoppo, Daniele; Borgio, Luca; Rajendran, Senthilkumar; Grandi, Francesca; Porzionato, Andrea; Macchi, Veronica; De Caro, Raffaele

2016-01-01

In regenerative neurobiology, Ciliary Neurotrophic Factor (CNTF) is raising high interest as a multifunctional neurocytokine, playing a key role in the regeneration of injured peripheral nerves. Despite its promising trophic and regulatory activity, its clinical application is limited by the onset of severe side effects, due to the lack of efficient intracellular trafficking after administration. In this study, recombinant CNTF linked to the transactivator transduction domain (TAT) was investigated in vitro and found to be an optimized fusion protein which preserves neurotrophic activity, besides enhancing cellular uptake for therapeutic advantage. Moreover, a compelling protein delivery method was defined, in the future perspective of improving nerve regeneration strategies. Following determination of TAT-CNTF molecular weight and concentration, its specific effect on neural SH-SY5Y and PC12 cultures was assessed. Cell proliferation assay demonstrated that the fusion protein triggers PC12 cell growth within 6 h of stimulation. At the same time, the activation of signal transduction pathway and enhancement of cellular trafficking were found to be accomplished in both neural cell lines after specific treatment with TAT-CNTF. Finally, the recombinant growth factor was successfully loaded on oxidized polyvinyl alcohol (PVA) scaffolds, and more efficiently released when polymer oxidation rate increased. Taken together, our results highlight that the TAT domain addiction to the protein sequence preserves CNTF specific neurotrophic activity in vitro, besides improving cellular uptake. Moreover, oxidized PVA could represent an ideal biomaterial for the development of nerve conduits loaded with the fusion protein to be delivered to the site of nerve injury. - Highlights: • TAT-CNTF is an optimized fusion protein that preserves neurotrophic activity. • In neural cell lines, TAT-CNTF triggers the activation of signal transduction. • Fast cellular uptake of TAT-CNTF was

In vitro assessment of TAT — Ciliary Neurotrophic Factor therapeutic potential for peripheral nerve regeneration

Energy Technology Data Exchange (ETDEWEB)

Barbon, Silvia, E-mail: silvia.barbon@yahoo.it [Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padua (Italy); Foundation for Biology and Regenerative Medicine, Tissue Engineering and Signaling (TES) ONLUS, Via De Sanctis 10, Caselle di Selvazzano Dentro, 35030 Padua (Italy); Stocco, Elena, E-mail: elena.stocco@gmail.com [Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padua (Italy); Foundation for Biology and Regenerative Medicine, Tissue Engineering and Signaling (TES) ONLUS, Via De Sanctis 10, Caselle di Selvazzano Dentro, 35030 Padua (Italy); Negro, Alessandro, E-mail: alessandro.negro@unipd.it [Department of Biomedical Sciences, University of Padova, Via Colombo 3, 35121 Padua (Italy); Dalzoppo, Daniele, E-mail: daniele.dalzoppo@unipd.it [Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padua (Italy); Borgio, Luca, E-mail: borgio.luca@gmail.com [Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padua (Italy); Rajendran, Senthilkumar, E-mail: senthilstem@gmail.com [Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131 Padua (Italy); Grandi, Francesca, E-mail: francesca.grandi7825@gmail.com [Department of Women' s and Children' s Health, Pediatric Surgery, University of Padua, Via Giustiniani 3, 35121 Padua (Italy); Porzionato, Andrea, E-mail: andrea.porzionato@unipd.it [Section of Human Anatomy, Department of Molecular Medicine, University of Padua, Via Gabelli 65, 35121 Padua (Italy); Macchi, Veronica, E-mail: veronica.macchi@unipd.it [Section of Human Anatomy, Department of Molecular Medicine, University of Padua, Via Gabelli 65, 35121 Padua (Italy); De Caro, Raffaele, E-mail: raffaele.decaro@unipd.it [Section of Human Anatomy, Department of Molecular Medicine, University of Padua, Via Gabelli 65, 35121 Padua (Italy); and others

2016-10-15

In regenerative neurobiology, Ciliary Neurotrophic Factor (CNTF) is raising high interest as a multifunctional neurocytokine, playing a key role in the regeneration of injured peripheral nerves. Despite its promising trophic and regulatory activity, its clinical application is limited by the onset of severe side effects, due to the lack of efficient intracellular trafficking after administration. In this study, recombinant CNTF linked to the transactivator transduction domain (TAT) was investigated in vitro and found to be an optimized fusion protein which preserves neurotrophic activity, besides enhancing cellular uptake for therapeutic advantage. Moreover, a compelling protein delivery method was defined, in the future perspective of improving nerve regeneration strategies. Following determination of TAT-CNTF molecular weight and concentration, its specific effect on neural SH-SY5Y and PC12 cultures was assessed. Cell proliferation assay demonstrated that the fusion protein triggers PC12 cell growth within 6 h of stimulation. At the same time, the activation of signal transduction pathway and enhancement of cellular trafficking were found to be accomplished in both neural cell lines after specific treatment with TAT-CNTF. Finally, the recombinant growth factor was successfully loaded on oxidized polyvinyl alcohol (PVA) scaffolds, and more efficiently released when polymer oxidation rate increased. Taken together, our results highlight that the TAT domain addiction to the protein sequence preserves CNTF specific neurotrophic activity in vitro, besides improving cellular uptake. Moreover, oxidized PVA could represent an ideal biomaterial for the development of nerve conduits loaded with the fusion protein to be delivered to the site of nerve injury. - Highlights: • TAT-CNTF is an optimized fusion protein that preserves neurotrophic activity. • In neural cell lines, TAT-CNTF triggers the activation of signal transduction. • Fast cellular uptake of TAT-CNTF was

Corticospinal and Spinal Excitabilities Are Modulated during Motor Imagery Associated with Somatosensory Electrical Nerve Stimulation

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E. Traverse

2018-01-01

Full Text Available Motor imagery (MI, the mental simulation of an action, influences the cortical, corticospinal, and spinal levels, despite the lack of somatosensory afferent feedbacks. The aim of this study was to analyze the effect of MI associated with somatosensory stimulation (SS on the corticospinal and spinal excitabilities. We used transcranial magnetic stimulation and peripheral nerve stimulation to induce motor-evoked potentials (MEP and H-reflexes, respectively, in soleus and medialis gastrocnemius (MG muscles of the right leg. Twelve participants performed three tasks: (1 MI of submaximal plantar flexion, (2 SS at 65 Hz on the posterior tibial nerve with an intensity below the motor threshold, and (3 MI + SS. MEP and H-reflex amplitudes were recorded before, during, and after the tasks. Our results confirmed that MI increased corticospinal excitability in a time-specific manner. We found that MI+SS tended to potentiate MEP amplitude of the MG muscle compared to MI alone. We confirmed that SS decreased spinal excitability, and this decrease was partially compensated when combined with MI, especially for the MG muscle. The increase of CSE could be explained by a modulation of the spinal inhibitions induced by SS, depending on the amount of afferent feedbacks.

Effector/memory CD8+ T cells synergize with co-stimulation competent macrophages to trigger autoimmune peripheral neuropathy.

Science.gov (United States)

Yang, Mu; Shi, Xiang Qun; Peyret, Corentin; Oladiran, Oladayo; Wu, Sonia; Chambon, Julien; Fournier, Sylvie; Zhang, Ji

2018-04-05

Autoimmune peripheral neuropathy (APN) such as Guillain Barre Syndrome (GBS) is a debilitating illness and sometimes life threatening. The molecular and cellular mechanisms remain elusive but exposure to environmental factors including viral/bacterial infection and injury is highly associated with disease incidence. We demonstrated previously that both male and female B7.2 (CD86) transgenic L31 and L31/CD4KO mice develop spontaneous APN. Here we further reveal that CD8 + T cells in these mice exhibit an effector/memory phenotype, which bears a resemblance to the CD8 + T cell response following persistent cytomegalovirus (CMV) infection in humans and mice, whilst CMV has been considered as one of the most relevant pathogens in APN development. These activated, peripheral myelin Ag specific CD8 + T cells are required for the disease initiation. While an injury to a peripheral nerve results in Wallerian degeneration in control littermates, the same injury accelerates the development of APN in other non-injured nerves of L31 mice which have a predisposed inflammatory background consisting of effector/memory CD8 + T (CD8 + T EM ) cells. However, CD8 + T EM cells alone are not sufficient. A certain threshold of B7.2 expression on nerve macrophages is an additional requisite. Our findings reveal that indeed, the synergism between CD8 + T EM cells and co-stimulation competent macrophages is crucial in inducing autoimmune-mediated peripheral neuropathy. The identification of decisive molecular/cellular players connecting environmental triggers and the occurrence of APN provides opportunities to prevent disease onset, reduce relapses and develop new therapeutic strategies. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Evidence for a systemic regulation of neurotrophin synthesis in response to peripheral nerve injury.

Science.gov (United States)

Shakhbazau, Antos; Martinez, Jose A; Xu, Qing-Gui; Kawasoe, Jean; van Minnen, Jan; Midha, Rajiv

2012-08-01

Up-regulation of neurotrophin synthesis is an important mechanism of peripheral nerve regeneration after injury. Neurotrophin expression is regulated by a complex series of events including cell interactions and multiple molecular stimuli. We have studied neurotrophin synthesis at 2 weeks time-point in a transvertebral model of unilateral or bilateral transection of sciatic nerve in rats. We have found that unilateral sciatic nerve transection results in the elevation of nerve growth factor (NGF) and NT-3, but not glial cell-line derived neurotrophic factor or brain-derived neural factor, in the uninjured nerve on the contralateral side, commonly considered as a control. Bilateral transection further increased NGF but not other neurotrophins in the nerve segment distal to the transection site, as compared to the unilateral injury. To further investigate the distinct role of NGF in regeneration and its potential for peripheral nerve repair, we transduced isogeneic Schwann cells with NGF-encoding lentivirus and transplanted the over-expressing cells into the distal segment of a transected nerve. Axonal regeneration was studied at 2 weeks time-point using pan-neuronal marker NF-200 and found to directly correlate with NGF levels in the regenerating nerve. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve Peripheral Nerve Repair and Functional Outcomes

Science.gov (United States)

2017-07-01

with autologous mesenchymal stem cells . Exp Neurol. 2007 Apr; 204(2):658-66. 19. Dezawa M., et al., Sciatic nerve regeneration in rats induced by...36 23. Mimura T., et al., Peripheral nerve regeneration by transplantation of bone marrow stromal cell -derived Schwann cells in adult rats. J...AWARD NUMBER: W81XWH-15-2-0026 TITLE: Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve

Peripheral nerve block in patients with Ehlers-Danlos syndrome, hypermobility type: a case series.

Science.gov (United States)

Neice, Andrew E; Stubblefield, Eryn E; Woodworth, Glenn E; Aziz, Michael F

2016-09-01

Ehlers-Danlos syndrome (EDS) is an inherited disease characterized by defects in various collagens or their post translational modification, with an incidence estimated at 1 in 5000. Performance of peripheral nerve block in patients with EDS is controversial, due to easy bruising and hematoma formation after injections as well as reports of reduced block efficacy. The objective of this study was to review the charts of EDS patients who had received peripheral nerve block for any evidence of complications or reduced efficacy. Case series, chart review. Academic medical center. Patients with a confirmed or probable diagnosis of EDS who had received a peripheral nerve block in the last 3 years were identified by searching our institutions electronic medical record system. The patients were classified by their subtype of EDS. Patients with no diagnosed subtype were given a probable subtype based on a chart review of the patient's symptoms. Patient charts were reviewed for any evidence of complications or reduced block efficacy. A total of 21 regional anesthetics, on 16 unique patients were identified, 10 of which had a EDS subtype diagnosis. The majority of these patients had a diagnosis of hypermobility-type EDS. No block complications were noted in any patients. Two block failures requiring repeat block were noted, and four patients reported uncontrolled pain on postoperative day one despite successful placement of a peripheral nerve catheter. Additionally, blocks were performed without incident in patients with classical-type and vascular-type EDS although the number was so small that no conclusions can be drawn about relative safety of regional anesthesia in these groups. This series fails to show an increased risk of complications of peripheral nerve blockade in patients with hypermobility-type EDS. Copyright © 2016 Elsevier Inc. All rights reserved.

21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

Science.gov (United States)

2010-04-01

... pain relief. 882.5890 Section 882.5890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to...

Peripheral Nerve Blocks for the Treatment of Headache in Older Adults: A Retrospective Study.

Science.gov (United States)

Hascalovici, Jacob R; Robbins, Matthew S

2017-01-01

The objective of this study is to provide demographical and clinical descriptions of patients age 65 years old and older who were treated with peripheral nerve blocks (PNBs) at our institution and evaluate the safety and efficacy of this treatment. Headache disorders are common, disabling chronic neurological diseases that often persist with advancing age. Geriatric headache management poses unique therapeutic challenges because of considerations of comorbidity, drug interactions, and adverse effects. Peripheral nerve blocks are commonly used for acute and short-term prophylactic treatment for headache disorders and may be a safer alternative to standard pharmacotherapy in this demographic. We performed a single center, retrospective chart review of patients at least 65 years of age who received peripheral nerve blocks for headache management over a 6 year period. Sixty-four patients were mostly female (78%) with an average age of 71 years (range 65-94). Representative headache diagnoses were chronic migraine 50%, episodic migraine 12.5%, trigeminal autonomic cephalalgia 9.4%, and occipital neuralgia 7.8%. Average number of headache days/month was 23. Common comorbidities were hypertension 48%, hyperlipidemia 42%, arthritis 27%, depression 47%, and anxiety 33%. Eighty-nine percent were prescribed at least 1 medication fulfilling the Beers criteria. The average number of peripheral nerve blocks per patient was 4. Peripheral nerve blocks were felt to be effective in 73% for all headaches, 81% for chronic migraine, 75% for episodic migraine, 67% for chronic tension type headache, 67% for new daily persistent headache, and 60% for occipital neuralgia. There were no adverse events related to PNBs reported. PNBs might be a safe and effective alternative headache management strategy for older adults. Medical and psychiatric comorbidities, medication overuse, and Beers list medication rates were extraordinarily high, giving credence to the use of peripherally administered

A novel concept for continuous peripheral nerve blocks. Presentation of a new ultrasound-guided device

DEFF Research Database (Denmark)

Rothe, C; Steen-Hansen, C; Madsen, M H

2015-01-01

positioning as well as during later in-plane readjustment of the catheter. We tested the system in the popliteal region of two fresh cadavers in a preliminary proof of concept study. RESULTS: Both initial placement and secondary readjustment were precise, judged by the catheter orifices placed close......BACKGROUND: Existing techniques for placing and maintaining the position of peripheral nerve catheters are associated with variable success rates and frequent secondary failures. These factors may affect the clinical efficacy and usefulness of peripheral nerve catheters. METHODS: We developed a new...... concept and prototype for ultrasound-guided in-plane positioning and readjustment of peripheral nerve catheters (patent pending). The integrated catheter-needle prototype comprises three parts: a curved needle, a catheter with clear echogenic markings attached to the needle tail and a detachable hub...

Delayed repair of the peripheral nerve: a novel model in the rat sciatic nerve.

Science.gov (United States)

Wu, Peng; Spinner, Robert J; Gu, Yudong; Yaszemski, Michael J; Windebank, Anthony J; Wang, Huan

2013-03-30

Peripheral nerve reconstruction is seldom done in the acute phase of nerve injury due to concomitant injuries and the uncertainty of the extent of nerve damage. A proper model that mimics true clinical scenarios is critical but lacking. The aim of this study is to develop a standardized, delayed sciatic nerve repair model in rats and validate the feasibility of direct secondary neurrorraphy after various delay intervals. Immediately or 1, 4, 6, 8 and 12 weeks after sciatic nerve transection, nerve repair was carried out. A successful tension-free direct neurorraphy (TFDN) was defined when the gap was shorter than 4.0 mm and the stumps could be reapproximated with 10-0 stitches without detachment. Compound muscle action potential (CMAP) was recorded postoperatively. Gaps between the two nerve stumps ranged from 0 to 9 mm, the average being 1.36, 2.85, 3.43, 3.83 and 6.4 mm in rats with 1, 4, 6, 8 and 12 week delay, respectively. The rate of successful TFDN was 78% overall. CMAP values of 1 and 4 week delay groups were not different from the immediate repair group, whereas CMAP amplitudes of 6, 8 and 12 week delay groups were significantly lower. A novel, standardized delayed nerve repair model is established. For this model to be sensitive, the interval between nerve injury and secondary repair should be at least over 4 weeks. Thereafter the longer the delay, the more challenging the model is for nerve regeneration. The choice of delay intervals can be tailored to meet specific requirements in future studies. Copyright © 2013 Elsevier B.V. All rights reserved.

Tumefactive appearance of peripheral nerve involvement in hematologic malignancies: a new imaging association

Energy Technology Data Exchange (ETDEWEB)

Capek, Stepan [Mayo Clinic, Department of Neurosurgery, Rochester, Minnesota (United States); St. Anne' s University Hospital Brno, International Clinical Research Center, Brno (Czech Republic); Hebert-Blouin, Marie-Noelle [McGill University, Department of Neurologic Surgery, Montreal, Quebec (Canada); Puffer, Ross C.; Spinner, Robert J. [Mayo Clinic, Department of Neurosurgery, Rochester, Minnesota (United States); Martinoli, Carlo [Universita degli Studi di Genova, Department of Radiology, Genova (Italy); Frick, Matthew A.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

2015-04-29

In neurolymphomatosis (NL), the affected nerves are typically described to be enlarged and hyperintense on T2W MR sequences and to avidly enhance on gadolinium-enhanced T1WI. This pattern is highly non-specific. We recently became aware of a ''tumefactive pattern'' of NL, neuroleukemiosis (NLK) and neuroplasmacytoma (NPLC), which we believe is exclusive to hematologic diseases affecting peripheral nerves. We defined a ''tumefactive'' appearance as complex, fusiform, hyperintense on T2WI, circumferential tumor masses encasing the involved peripheral nerves. The nerves appear to be infiltrated by the tumor. Both structures show varying levels of homogenous enhancement. We reviewed our series of 52 cases of NL in search of this pattern; two extra outside cases of NL, three cases of NLK, and one case of NPLC were added to the series. We identified 20 tumefactive lesions in 18 patients (14 NL, three NLK, one NPLC). The brachial plexus (n = 7) was most commonly affected, followed by the sciatic nerve (n = 6) and lumbosacral plexus (n = 3). Four patients had involvement of other nerves. All were proven by biopsy: the diagnosis was high-grade lymphoma (n = 12), low-grade lymphoma (n = 3), acute leukemia (n = 2), and plasmacytoma (n = 1). We present a new imaging pattern of ''tumefactive'' neurolymphomatosis, neuroleukemiosis, or neuroplasmacytoma in a series of 18 cases. We believe this pattern is associated with hematologic diseases directly involving the peripheral nerves. Knowledge of this association can provide a clue to clinicians in establishing the correct diagnosis. Bearing in mind that tumefactive NL, NLK, and NPLC is a newly introduced imaging pattern, we still recommend to biopsy patients with suspicion of a malignancy. (orig.)

A survey of emergency medicine and orthopaedic physicians’ knowledge, attitude, and practice towards the use of peripheral nerve blocks

Directory of Open Access Journals (Sweden)

Ayalew Zewdie

2017-06-01

Discussion: This study indicates peripheral nerve blocks are likely underutilised due to lack of training. There was a positive attitude towards peripheral nerve blocks but gaps on knowledge and practice.

Transplantation of olfactory ensheathing cells as adjunct cell therapy for peripheral nerve injury.

Science.gov (United States)

Radtke, Christine; Wewetzer, Konstantin; Reimers, Kerstin; Vogt, Peter M

2011-01-01

Traumatic events, such as work place trauma or motor vehicle accident violence, result in a significant number of severe peripheral nerve lesions, including nerve crush and nerve disruption defects. Transplantation of myelin-forming cells, such as Schwann cells (SCs) or olfactory ensheathing cells (OECs), may be beneficial to the regenerative process because the applied cells could mediate neurotrophic and neuroprotective effects by secretion of chemokines. Moreover, myelin-forming cells are capable of bridging the repair site by establishing an environment permissive to axonal regeneration. The cell types that are subject to intense investigation include SCs and OECs either derived from the olfactory bulb or the olfactory mucosa, stromal cells from bone marrow (mesenchymal stem cells, MSCs), and adipose tissue-derived cells. OECs reside in the peripheral and central nervous system and have been suggested to display unique regenerative properties. However, so far OECs were mainly used in experimental studies to foster central regeneration and it was not until recently that their regeneration-promoting activity for the peripheral nervous system was recognized. In the present review, we summarize recent experimental evidence regarding the regenerative effects of OECs applied to the peripheral nervous system that may be relevant to design novel autologous cell transplantation therapies. © 2011 Cognizant Comm. Corp.

Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking.

Science.gov (United States)

Colzato, Lorenza S; Ritter, Simone M; Steenbergen, Laura

2018-03-01

Creativity is one of the most important cognitive skills in our complex and fast-changing world. Previous correlative evidence showed that gamma-aminobutyric acid (GABA) is involved in divergent but not convergent thinking. In the current study, a placebo/sham-controlled, randomized between-group design was used to test a causal relation between vagus nerve and creativity. We employed transcutaneous vagus nerve stimulation (tVNS), a novel non-invasive brain stimulation technique to stimulate afferent fibers of the vagus nerve and speculated to increase GABA levels, in 80 healthy young volunteers. Creative performance was assessed in terms of divergent thinking (Alternate Uses Task) and convergent thinking tasks (Remote Associates Test, Creative Problem Solving Task, Idea Selection Task). Results demonstrate active tVNS, compared to sham stimulation, enhanced divergent thinking. Bayesian analysis reported the data to be inconclusive regarding a possible effect of tVNS on convergent thinking. Therefore, our findings corroborate the idea that the vagus nerve is causally involved in creative performance. Even thought we did not directly measure GABA levels, our results suggest that GABA (likely to be increased in active tVNS condition) supports the ability to select among competing options in high selection demand (divergent thinking) but not in low selection demand (convergent thinking). Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Study of Tapping by the Unaffected Finger of Patients Presenting with Central and Peripheral Nerve Damage

OpenAIRE

Zhang, Lingli; Han, Xiuying; Li, Peihong; Liu, Yang; Zhu, Yulian; Zou, Jun; Yu, Zhusheng

2015-01-01

Aim Whether the unaffected function of the hand of patients presenting with nerve injury is affected remains inconclusive. We aimed to evaluate whether there are differences in finger tapping following central or peripheral nerve injury compared with the unaffected hand and the ipsilateral hand of a healthy subject. Methods Thirty right brain stroke patients with hemiplegia, 30 left arm peripheral nerve injury cases, and 60 healthy people were selected. We tested finger tapping of ...

In vivo assessment of peripheral nerve regeneration by diffusion tensor imaging.

Science.gov (United States)

Morisaki, Shinsuke; Kawai, Yuko; Umeda, Masahiro; Nishi, Mayumi; Oda, Ryo; Fujiwara, Hiroyoshi; Yamada, Kei; Higuchi, Toshihiro; Tanaka, Chuzo; Kawata, Mitsuhiro; Kubo, Toshikazu

2011-03-01

To evaluate the sensitivity of diffusion tensor imaging (DTI) in assessing peripheral nerve regeneration in vivo. We assessed the changes in the DTI parameters and histological analyses after nerve injury to examine degeneration and regeneration in the rat sciatic nerves. For magnetic resonance imaging (MRI), 16 rats were randomly divided into two groups: group P (permanently crushed; n = 7) and group T (temporally crushed; n = 9). Serial MRI of the right leg was performed before the operation, and then performed at the timepoints of 1, 2, 3, and 4 weeks after the crush injury. The changes in fractional anisotropy (FA), axial diffusivity (λ(∥)), and radial diffusivity (λ(⟂)) were quantified. For histological analyses, the number of axons and the myelinated axon areas were quantified. Decreased FA and increased λ(⟂) were observed in the degenerative phase, and increased FA and decreased λ(⟂) were observed in the regenerative phase. The changes in FA and λ(⟂) were strongly correlated with histological changes, including axonal and myelin regeneration. DTI parameters, especially λ(⟂) , can be good indicators for peripheral nerve regeneration and can be applied as noninvasive diagnostic tools for a variety of neurological diseases. Copyright © 2011 Wiley-Liss, Inc.

Omega-3 polyunsaturated fatty acid supplementation for improving peripheral nerve health: protocol for a systematic review.

Science.gov (United States)

Zhang, Alexis Ceecee; MacIsaac, Richard J; Roberts, Leslie; Kamel, Jordan; Craig, Jennifer P; Busija, Lucy; Downie, Laura E

2018-03-25

Damage to peripheral nerves occurs in a variety of health conditions. Preserving nerve integrity, to prevent progressive nerve damage, remains a clinical challenge. Omega-3 polyunsaturated fatty acids (PUFAs) are implicated in the development and maintenance of healthy nerves and may be beneficial for promoting peripheral nerve health. The aim of this systematic review is to assess the effects of oral omega-3 PUFA supplementation on peripheral nerve integrity, including both subjective and objective measures of peripheral nerve structure and/or function. A systematic review of randomised controlled trials that have evaluated the effects of omega-3 PUFA supplementation on peripheral nerve assessments will be conducted. Comprehensive electronic database searches will be performed in Ovid MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), US National Institutes of Health Clinical Trials Registry and the WHO International Clinical Trials Registry Platform. The title, abstract and keywords of identified articles will be assessed for eligibility by two reviewers. Full-text articles will be obtained for all studies judged as eligible or potentially eligible; these studies will be independently assessed by two reviewers to determine eligibility. Disagreements will be resolved by consensus. Risk of bias assessment will be performed using the Cochrane Collaboration risk of bias tool to appraise the quality of included studies. If clinically meaningful, and there are a sufficient number of eligible studies, a meta-analysis will be conducted and a summary of findings table will be provided. This is a systematic review that will involve the analysis of previously published data, and therefore ethics approval is not required. A manuscript reporting the results of this systematic review will be published in a peer-reviewed journal and may also be presented at relevant scientific conferences. CRD42018086297. © Article author(s) (or their employer

Improving patient knowledge about sacral nerve stimulation using a patient based educational video.

Science.gov (United States)

Jeppson, Peter Clegg; Clark, Melissa A; Hampton, Brittany Star; Raker, Christina A; Sung, Vivian W

2013-10-01

We developed a patient based educational video to address the information needs of women considering sacral nerve stimulation for overactive bladder. Five semistructured focus groups were used to identify patient knowledge gaps, information needs, patient acceptable terminology and video content preferences for a patient based sacral nerve stimulation educational video. Each session was transcribed, independently coded by 2 coders and examined using an iterative method. A 16-minute educational video was created to address previously identified knowledge gaps and information needs using patient footage, 3-dimensional animation and peer reviewed literature. We developed a questionnaire to evaluate participant sacral nerve stimulation knowledge and therapy attitudes. We then performed a randomized trial to assess the effect of the educational video vs the manufacturer video on patient knowledge and attitudes using our questionnaire. We identified 10 patient important domains, including 1) anatomy, 2) expectations, 3) sacral nerve stimulation device efficacy, 4) surgical procedure, 5) surgical/device complications, 6) post-procedure recovery, 7) sacral nerve stimulation side effects, 8) postoperative restrictions, 9) device maintenance and 10) general sacral nerve stimulation information. A total of 40 women with overactive bladder were randomized to watch the educational (20) or manufacturer (20) video. Knowledge scores improved in each group but the educational video group had a greater score improvement (76.6 vs 24.2 points, p <0.0001). Women who watched the educational video reported more favorable attitudes and expectations about sacral nerve stimulation therapy. Women with overactive bladder considering sacral nerve stimulation therapy have specific information needs. The video that we developed to address these needs was associated with improved short-term patient knowledge. Copyright © 2013 American Urological Association Education and Research, Inc

Peripheral afferent mechanisms underlying acupuncture inhibition of cocaine behavioral effects in rats.

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Seol Ah Kim

Full Text Available Administration of cocaine increases locomotor activity by enhancing dopamine transmission. To explore the peripheral mechanisms underlying acupuncture treatment for drug addiction, we developed a novel mechanical acupuncture instrument (MAI for objective mechanical stimulation. The aim of this study was to evaluate whether acupuncture inhibition of cocaine-induced locomotor activity is mediated through specific peripheral nerves, the afferents from superficial or deep tissues, or specific groups of nerve fibers. Mechanical stimulation of acupuncture point HT7 with MAI suppressed cocaine-induced locomotor activity in a stimulus time-dependent manner, which was blocked by severing the ulnar nerve or by local anesthesia. Suppression of cocaine-induced locomotor activity was elicited after HT7 stimulation at frequencies of either 50 (for Meissner corpuscles or 200 (for Pacinian corpuscles Hz and was not affected by block of C/Aδ-fibers in the ulnar nerve with resiniferatoxin, nor generated by direct stimulation of C/Aδ-fiber afferents with capsaicin. These findings suggest that HT7 inhibition of cocaine-induced locomotor activity is mediated by A-fiber activation of ulnar nerve that originates in superficial and deep tissue.

Optical cuff for optogenetic control of the peripheral nervous system

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Michoud, Frédéric; Sottas, Loïc; Browne, Liam E.; Asboth, Léonie; Latremoliere, Alban; Sakuma, Miyuki; Courtine, Grégoire; Woolf, Clifford J.; Lacour, Stéphanie P.

2018-02-01

Objective. Nerves in the peripheral nervous system (PNS) contain axons with specific motor, somatosensory and autonomic functions. Optogenetics offers an efficient approach to selectively activate axons within the nerve. However, the heterogeneous nature of nerves and their tortuous route through the body create a challenging environment to reliably implant a light delivery interface. Approach. Here, we propose an optical peripheral nerve interface—an optocuff—, so that optogenetic modulation of peripheral nerves become possible in freely behaving mice. Main results. Using this optocuff, we demonstrate orderly recruitment of motor units with epineural optical stimulation of genetically targeted sciatic nerve axons, both in anaesthetized and in awake, freely behaving animals. Behavioural experiments and histology show the optocuff does not damage the nerve thus is suitable for long-term experiments. Significance. These results suggest that the soft optocuff might be a straightforward and efficient tool to support more extensive study of the PNS using optogenetics.

Ultrasound assessment on selected peripheral nerve pathologies. Part I: Entrapment neuropathies of the upper limb – excluding carpal tunnel syndrome

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Berta Kowalska

2012-09-01

Full Text Available Ultrasound (US is one of the methods for imaging entrapment neuropathies, post-trau‑ matic changes to nerves, nerve tumors and postoperative complications to nerves. This type of examination is becoming more and more popular, not only for economic reasons, but also due to its value in making accurate diagnosis. It provides a very precise assess‑ ment of peripheral nerve trunk pathology – both in terms of morphology and localization. During examination there are several options available to the specialist: the making of a dynamic assessment, observation of pain radiation through the application of precise palpation and the comparison of resultant images with the contra lateral limb. Entrap‑ ment neuropathies of the upper limb are discussed in this study, with the omission of median nerve neuropathy at the level of the carpal canal, as extensive literature on this subject exists. The following pathologies are presented: pronator teres muscle syndrome, anterior interosseus nerve neuropathy, ulnar nerve groove syndrome and cubital tun‑ nel syndrome, Guyon’s canal syndrome, radial nerve neuropathy, posterior interosseous nerve neuropathy, Wartenberg’s disease, suprascapular nerve neuropathy and thoracic outlet syndrome. Peripheral nerve examination technique has been presented in previous articles presenting information about peripheral nerve anatomy [Journal of Ultrasonog‑ raphy 2012; 12 (49: 120–163 – Normal and sonographic anatomy of selected peripheral nerves. Part I: Sonohistology and general principles of examination, following the exam‑ ple of the median nerve; Part II: Peripheral nerves of the upper limb; Part III: Peripheral nerves of the lower limb]. In this article potential compression sites of particular nerves are discussed, taking into account pathomechanisms of damage, including predisposing anatomical variants (accessory muscles. The parameters of ultrasound assessment have been established – echogenicity and

Pannexin 1 Modulates Axonal Growth in Mouse Peripheral Nerves

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Steven M. Horton

2017-11-01

Full Text Available The pannexin family of channels consists of three members—pannexin-1 (Panx1, pannexin-2 (Panx2, and pannexin-3 (Panx3 that enable the exchange of metabolites and signaling molecules between intracellular and extracellular compartments. Pannexin-mediated release of intracellular ATP into the extracellular space has been tied to a number of cellular activities, primarily through the activity of type P2 purinergic receptors. Previous work indicates that the opening of Panx1 channels and activation of purinergic receptors by extracellular ATP may cause inflammation and apoptosis. In the CNS (central nervous system and PNS (peripheral nervous system, coupled pannexin, and P2 functions have been linked to peripheral sensitization (pain pathways. Purinergic pathways are also essential for other critical processes in the PNS, including myelination and neurite outgrowth. However, whether such pathways are pannexin-dependent remains to be determined. In this study, we use a Panx1 knockout mouse model and pharmacological inhibitors of the Panx1 and the ATP-mediated signaling pathway to fill gaps in our understanding of Panx1 localization in peripheral nerves, roles for Panx1 in axonal outgrowth and myelination, and neurite extension. Our data show that Panx1 is localized to axonal, myelin, and vascular compartments of the peripheral nerves. Knockout of Panx1 gene significantly increased axonal caliber in vivo and axonal growth rate in cultured dorsal root ganglia (DRG neurons. Furthermore, genetic knockout of Panx1 or inhibition of components of purinergic signaling, by treatment with probenecid and apyrase, resulted in denser axonal outgrowth from cultured DRG explants compared to untreated wild-types. Our findings suggest that Panx1 regulates axonal growth in the peripheral nervous system.

Should we add clonidine to local anesthetic for peripheral nerve blockade? A qualitative systematic review of the literature.

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McCartney, Colin J L; Duggan, Edel; Apatu, Emma

2007-01-01

Although clonidine has been shown to prolong analgesia in central neuraxial blocks, its use in peripheral nerve blocks remains controversial. We performed a systematic review of the current literature to determine the benefit of adding clonidine to peripheral nerve blocks. A systematic, qualitative review of double-blind randomized controlled trials on the benefit of clonidine as an adjunct to peripheral nerve block was performed. Studies were identified by searching PubMed (www.ncbi.nlm.nih.gov/entrez) and EMBASE (www.embase.com) databases (July 1991 to October 2006) for terms related to clonidine as an adjunct to peripheral nerve blocks. Studies were classified as supportive if the use of clonidine demonstrated reduced pain and total analgesic consumption, or prolonged block duration versus negative if no difference was found. Twenty-seven studies were identified that met the inclusion criteria. Five studies included a systemic control group. The total number of patients reviewed was 1,385. The dose of clonidine varied from 30 to 300 mug. Overall 15 studies supported the use of clonidine as an adjunct to peripheral nerve blocks with 12 studies failing to show a benefit. Based on qualitative analysis, clonidine appeared to prolong analgesia when added to intermediate-acting local anesthetics for axillary and peribulbar blocks. Clonidine improves duration of analgesia and anesthesia when used as an adjunct to intermediate-acting local anesthetics for some peripheral nerve blocks. Side-effects appear to be limited at doses up to 150 mug. Evidence is lacking for the use of clonidine as an adjunct to local anesthetics for continuous catheter techniques. Further research is required to examine the peripheral analgesic mechanism of clonidine.

Malignant Peripheral Nerve Sheath Tumor: MRI and CT Findings

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K. O. Kragha

2015-01-01

important in its diagnosis. A rare case of MPNST that produced urinary retention and bowel incontinence is presented that may aid clinicians in the diagnosis of this rare clinical entity. Motor weakness, central enhancement, and immunohistochemistry may assist in the diagnosis of MPNST and differentiation between benign peripheral nerve sheath tumor (BPNST and MPNST.

Meeting report on the first Iranian congress of electrodiagnosis in peripheral nerve lesions

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Bahrami Hasan M

2007-04-01

Full Text Available Abstract The Department of Physical Medicine, Rehabilitation and Electrodiagnosis of Shaheed Beheshti Medical University in collaboration with the Iranian Society of Physical Medicine and Rehabilitation (ISPMR held the 1st Congress of Electrodiagnostic Medicine in Peripheral Nerve Lesions on December 21–22, 2006. Electrodiagnostic medicine is a specific branch of medicine used by specialist physicians in the field of physical medicine and rehabilitation and/or neurology to diagnose, prognosticate and plan treatment options of peripheral nerve lesions. This meeting was hold to discuss multidisciplinary approaches to this common and important topic in the medical field.

Study of nerve fibers nature reinforcing duodenal contractions by electrical stimulation of sympathetic nerve

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Sveshnikov D.S.

2011-09-01

Full Text Available The subject of the article is to investigate the mechanism of increased reactions by electrical stimulation of the sympathetic nerve. Materials and methods: Experiments on dogs have shown that stimulant reactions during blockade of a-adrenergic by phentolamine and (3-adrenergic receptors with propranolol were completely eliminated by lizer-gol —the blocker of 5-HT12-receptors. Results: Infusion of lizergol did not influence on duodenal motor activity and the function of the vagus nerve. Conclusion: Effector neuron is found out to be serotonergic and its action is provided by 5-HT1 2 receptors

Severe muscle atrophy due to spinal cord injury can be reversed in complete absence of peripheral nerves

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Simona Boncompagni

2012-12-01

Full Text Available In the last years, a new efficient treatment has been developed to treat paralyzed skeletal muscle of patients affected by spinal cord injury (SCI. The capability of the functional electrical stimulation (FES to improve trophism and in some cases muscle function, are now well documented both in animals after experimental cord lesion, and in humans, generally after traumatic cord lesion. This new findings makes FES an important tool for the rehabilitation of SCI patients. FES stimulation has been proven to be an effective method used to retard muscle atrophy and improve recovery after reinnervation. Sophisticated FES devices have been developed for restoring function in the upper and lower extremities, the bladder and bowel, and the respiratory system of SCI patients. However, there are SCI cases, such as those affected by flaccid paralysis, in which the musculature is not treated with FES rehabilitation therapy. This is because conventional FES apparatuses are designed for direct stimulation of peripheral nerves that need small currents to be depolarized, and are not effective in patients that have lost their peripheral nerves, and, therefore, require higher currents for the direct depolarization of the muscle fibers. Lack of muscle treatment generates, as a secondary problem, a long series of alterations to tissues other than muscle, such as bones (osteoporosis, skin (pressure sores, decubital ulcers, etc., that are a direct consequence of inactivity and poor blood supply to the denervated areas. These complications represent an extremely serious problem for the general health of the injured individuals, who usually have a shorter than normal life span. In the hopes of changing this common belief, an innovative rehabilitation procedure, based on FES, has been developed with the aim of reversing long-lasting muscle atrophy in the muscles of the lower extremities of SCI patients affected by complete lesion of the conus cauda, i.e. that have no

Tyrosinase expression in malignant melanoma, desmoplastic melanoma, and peripheral nerve tumors

DEFF Research Database (Denmark)

Boyle, Jenny L; Haupt, Helen M; Stern, Jere B

2002-01-01

of tyrosinase expression in the differential diagnosis of melanoma, desmoplastic melanoma, and peripheral nerve sheath tumors. DESIGN: Immunoreactivity for tyrosinase, HMB-45 (anti-gp100 protein), S100 protein, CD34, and vimentin was studied in 70 tumors, including 15 melanomas (5 desmoplastic, 4 amelanotic, 6...... at 121 degrees C. RESULTS: All melanomas demonstrated positive immunostaining for tyrosinase, HMB-45, and S100 protein. Immunoreactivity for HMB-45 was generally stronger than that for tyrosinase in amelanotic lesions and significantly stronger in 1 of the desmoplastic lesions. The 4 pigmented...... neurofibromas were focally positive for tyrosinase, but did not stain for HMB-45. The pigmented schwannoma was focally positive for both tyrosinase and HMB-45. The malignant peripheral nerve sheath tumors, dermatofibrosarcoma protuberans, and dermatofibromas were nonreactive for tyrosinase and HMB-45...

Investigation of assumptions underlying current safety guidelines on EM-induced nerve stimulation

Science.gov (United States)

Neufeld, Esra; Vogiatzis Oikonomidis, Ioannis; Iacono, Maria Ida; Angelone, Leonardo M.; Kainz, Wolfgang; Kuster, Niels

2016-06-01

An intricate network of a variety of nerves is embedded within the complex anatomy of the human body. Although nerves are shielded from unwanted excitation, they can still be stimulated by external electromagnetic sources that induce strongly non-uniform field distributions. Current exposure safety standards designed to limit unwanted nerve stimulation are based on a series of explicit and implicit assumptions and simplifications. This paper demonstrates the applicability of functionalized anatomical phantoms with integrated coupled electromagnetic and neuronal dynamics solvers for investigating the impact of magnetic resonance exposure on nerve excitation within the full complexity of the human anatomy. The impact of neuronal dynamics models, temperature and local hot-spots, nerve trajectory and potential smoothing, anatomical inhomogeneity, and pulse duration on nerve stimulation was evaluated. As a result, multiple assumptions underlying current safety standards are questioned. It is demonstrated that coupled EM-neuronal dynamics modeling involving realistic anatomies is valuable to establish conservative safety criteria.

Evaluation of the chitosan/glycerol-β-phosphate disodium salt hydrogel application in peripheral nerve regeneration

International Nuclear Information System (INIS)

Zheng Lu; Zhang Xiufang; Gong Yandao; Ao Qiang; Han Hongyan

2010-01-01

Research efforts have been devoted to evaluating the application of the chitosan (CS)/glycerol-β-phosphate (GP) disodium salt hydrogel in peripheral nerve regeneration. The gelation time was determined to be 770 s using ultraviolet spectrophotometry. A standard 10 mm long rat sciatic nerve defect model was employed, followed by bridging the proximal and distal stumps with chitosan conduits injected with the Schwann cell-containing hydrogel. Injections of the blank hydrogel, Schwann cell suspension and culture medium were used as controls. Two months later, electrophysiological assessment and fluorogold retrograde tracing showed that compound muscle action potentials (CMAPs) and fluorogold-labeled neurons were only detected in the Schwann cell suspension group and culture medium group. The rats were then killed, and implanted conduits were removed for examination. There were no regenerated nerves found in groups injected with the blank hydrogel or Schwann cell-containing hydrogel, while the other two groups clearly displayed regenerated nerves across the gaps. In the subsequent histological assessment, immunohistochemistry, toluidine blue staining and transmission electron microscopy were performed to evaluate the regenerated nerves. The relative wet weight ratio, Masson trichrome staining and acetylcholinesterase staining were employed for the examination of gastrocnemius muscles in all four groups. The Schwann cell suspension group showed the best results for all these indexes; the culture medium group ranked second and the two hydrogel-injected groups showed the least optimal results. In conclusion, our data revealed that the implanted CS/GP hydrogel actually impeded nerve regeneration, which is inconsistent with former in vitro reports and general supposition. We believe that the application of the CS/GP hydrogel in nerve regeneration requires a further study before a satisfactory result is obtained. In addition, the present study also confirmed that Schwann

A Study of Tapping by the Unaffected Finger of Patients Presenting with Central and Peripheral Nerve Damage

OpenAIRE

Lingli eZhang; Xiuying eHan; peihong eli; yang eliu; yulian ezhu; zhusheng eyu

2015-01-01

Aim: Whether the unaffected function of the hand of patients presenting with nerve injury is affected remains inconclusive. We aimed to evaluate whether there are differences in finger tapping following central or peripheral nerve injury compared with the unaffected hand and the ipsilateral hand of a healthy subject.Methods: 30 right brain stroke patients with hemiplegia, 30 left arm peripheral nerve injury cases and 60 healthy people were selected. We tested finger tapping of the right hands...

Early cyclosporin A treatment retards axonal degeneration in an experimental peripheral nerve injection injury model

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Ibrahim Erkutlu

2015-01-01

Full Text Available Injury to peripheral nerves during injections of therapeutic agents such as penicillin G potassium is common in developing countries. It has been shown that cyclosporin A, a powerful immunosuppressive agent, can retard Wallerian degeneration after peripheral nerve crush injury. However, few studies are reported on the effects of cyclosporin A on peripheral nerve drug injection injury. This study aimed to assess the time-dependent efficacy of cyclosporine-A as an immunosuppressant therapy in an experimental rat nerve injection injury model established by penicillin G potassium injection. The rats were randomly divided into three groups based on the length of time after nerve injury induced by penicillin G potassium administration (30 minutes, 8 or 24 hours. The compound muscle action potentials were recorded pre-injury, early post-injury (within 1 hour and 4 weeks after injury and compared statistically. Tissue samples were taken from each animal for histological analysis. Compared to the control group, a significant improvement of the compound muscle action potential amplitude value was observed only when cyclosporine-A was administered within 30 minutes of the injection injury (P < 0.05; at 8 or 24 hours after cyclosporine-A administration, compound muscle action potential amplitude was not changed compared with the control group. Thus, early immunosuppressant drug therapy may be a good alternative neuroprotective therapy option in experimental nerve injection injury induced by penicillin G potassium injection.

BDNF gene delivery mediated by neuron-targeted nanoparticles is neuroprotective in peripheral nerve injury.

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Lopes, Cátia D F; Gonçalves, Nádia P; Gomes, Carla P; Saraiva, Maria J; Pêgo, Ana P

2017-03-01

Neuron-targeted gene delivery is a promising strategy to treat peripheral neuropathies. Here we propose the use of polymeric nanoparticles based on thiolated trimethyl chitosan (TMCSH) to mediate targeted gene delivery to peripheral neurons upon a peripheral and minimally invasive intramuscular administration. Nanoparticles were grafted with the non-toxic carboxylic fragment of the tetanus neurotoxin (HC) to allow neuron targeting and were explored to deliver a plasmid DNA encoding for the brain-derived neurotrophic factor (BDNF) in a peripheral nerve injury model. The TMCSH-HC/BDNF nanoparticle treatment promoted the release and significant expression of BDNF in neural tissues, which resulted in an enhanced functional recovery after injury as compared to control treatments (vehicle and non-targeted nanoparticles), associated with an improvement in key pro-regenerative events, namely, the increased expression of neurofilament and growth-associated protein GAP-43 in the injured nerves. Moreover, the targeted nanoparticle treatment was correlated with a significantly higher density of myelinated axons in the distal stump of injured nerves, as well as with preservation of unmyelinated axon density as compared with controls and a protective role in injury-denervated muscles, preventing them from denervation. These results highlight the potential of TMCSH-HC nanoparticles as non-viral gene carriers to deliver therapeutic genes into the peripheral neurons and thus, pave the way for their use as an effective therapeutic intervention for peripheral neuropathies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges.

Science.gov (United States)

Pfister, Bryan J; Gordon, Tessa; Loverde, Joseph R; Kochar, Arshneel S; Mackinnon, Susan E; Cullen, D Kacy

2011-01-01

Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury.

Sensorimotor peripheral nerve function and physical activity in older men

DEFF Research Database (Denmark)

Lange-Maia, B. S.; Cauley, J A; Newman, Anne B

2016-01-01

We determined whether sensorimotor peripheral nerve (PN) function was associated with physical activity (PA) in older men. The Osteoporotic Fractures in Men Study Pittsburgh, PA, site (n = 328, age 78.8 ± 4.7 years) conducted PN testing, including: peroneal motor and sural sensory nerve conduction...... (latencies, amplitudes: CMAP and SNAP for motor and sensory amplitude, respectively), 1.4g/10g monoflament (dorsum of the great toe), and neuropathy symptoms. ANOVA and multivariate linear regression modeled PN associations with PA (Physical Activity Scale for the Elderly [PASE] and SenseWear Armband). After...

Use of paper for treatment of a peripheral nerve trauma in the rat.

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Kauppila, T; Jyväsjärvi, E; Murtomäki, S; Mansikka, H; Pertovaara, A; Virtanen, I; Liesi, P

1997-09-29

Reinnervation of the muscles and skin in the rat hindpaw was studied after transection and attempted repair of the sciatic nerve. Reconnecting the transected nerve with lens cleaning paper was at least as effective in rejoining the transected nerves as traditional microsurgical neurorraphy. Paper induced a slightly bigger fibrous scar around the site of transection than neurorraphy, but this scar did not cause impairment of functional recovery or excessive signs of neuropathic pain. We conclude that a paper graft can be used in restorative surgery of severed peripheral nerves.

Presacral abscess as a rare complication of sacral nerve stimulator implantation.

Science.gov (United States)

Gumber, A; Ayyar, S; Varia, H; Pettit, S

2017-03-01

A 50-year-old man with intractable anal pain attributed to proctalgia fugax underwent insertion of a sacral nerve stimulator via the right S3 vertebral foramen for pain control with good symptomatic relief. Thirteen months later, he presented with signs of sepsis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large presacral abscess. MRI demonstrated increased enhancement along the pathway of the stimulator electrode, indicating that the abscess was caused by infection introduced at the time of sacral nerve stimulator placement. The patient was treated with broad spectrum antibiotics, and the sacral nerve stimulator and electrode were removed. Attempts were made to drain the abscess transrectally using minimally invasive techniques but these were unsuccessful and CT guided transperineal drainage was then performed. Despite this, the presacral abscess progressed, developing enlarging gas locules and extending to the pelvic brim to involve the aortic bifurcation, causing hydronephrosis and radiological signs of impending sacral osteomyelitis. MRI showed communication between the rectum and abscess resulting from transrectal drainage. In view of the progressive presacral sepsis, a laparotomy was performed with drainage of the abscess, closure of the upper rectum and formation of a defunctioning end sigmoid colostomy. Following this, the presacral infection resolved. Presacral abscess formation secondary to an infected sacral nerve stimulator electrode has not been reported previously. Our experience suggests that in a similar situation, the optimal management is to perform laparotomy with drainage of the presacral abscess together with simultaneous removal of the sacral nerve stimulator and electrode.