Evaluation of radiation-induced peripheral nerve injury in rabbits with MR neurography using diffusion tensor imaging andT2measurements: Correlation with histological and functional changes

2015 ◽  
Vol 43 (6) ◽  
pp. 1492-1499 ◽  
Author(s):  
Qi Wan ◽  
Shiyang Wang ◽  
Jiaxuan Zhou ◽  
Qiao Zou ◽  
Yingshi Deng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Diffusion Tensor ◽  
Mr Neurography ◽  
Functional Changes ◽  
Radiation Induced

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

2015 ◽  
Vol 39 (3) ◽  
pp. E9 ◽  
Author(s):  
Richard B. Boyer ◽  
Nathaniel D. Kelm ◽  
D. Colton Riley ◽  
Kevin W. Sexton ◽  
Alonda C. Pollins ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Nerve Fibers ◽  
Nerve Transection ◽  
Nerve Injuries

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.

scholarly journals Initial findings in traumatic peripheral nerve injury and repair with diffusion tensor imaging

2021 ◽  
Author(s):  
Michael D. Pridmore ◽  
Gabriella E. Glassman ◽  
Alonda C. Pollins ◽  
Isaac V. Manzanera Esteve ◽  
Brian C. Drolet ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Diffusion Tensor ◽  
Injury And Repair

scholarly journals Diffusion tensor imaging to visualize axons in the setting of nerve injury and recovery

2015 ◽  
Vol 39 (3) ◽  
pp. E10 ◽  
Author(s):  
Thomas Anthony Gallagher ◽  
Neil G. Simon ◽  
Michel Kliot
Keyword(s):  
Diffusion Tensor Imaging ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerves ◽  
Diffusion Tensor ◽  
Nerve Fibers ◽  
Accurate Localization ◽  
Peripheral Nerve Trauma ◽  
Nerve Trauma ◽  
Diffusion Tensor Imaging Dti

Successful management of peripheral nerve trauma relies on accurate localization of the injury and grading of the severity of nerve injury to determine whether surgical intervention is required. Existing techniques, such as electrodiagnostic studies and conventional imaging modalities, provide important information, but are limited by being unable to distinguish severe nerve lesions in continuity that will recover from those that will not. Diffusion tensor imaging (DTI) and tractography of peripheral nerves provide a novel technique to localize and grade nerve injury, by assessing the integrity of the nerve fibers across the site of nerve injury. Diffusion tensor imaging and tractography also hold promise as markers of early nerve regeneration, prior to clinical and electrodiagnostic evidence of recovery. In the present review, the techniques of peripheral nerve DTI and tractography are discussed with respect to peripheral nerve trauma, with illustrative cases demonstrating potential roles of these novel approaches.

scholarly journals BDNF produced by cerebral microglia promotes cortical plasticity and pain hypersensitivity after peripheral nerve injury

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001337
Author(s):  
Lianyan Huang ◽  
Jianhua Jin ◽  
Kai Chen ◽  
Sikun You ◽  
Hongyang Zhang ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Cortical Plasticity ◽  
Conditional Knockout ◽  
Normal Density ◽  
Pain Hypersensitivity ◽  
Functional Changes ◽  
Beneficial Effects

Peripheral nerve injury–induced mechanical allodynia is often accompanied by abnormalities in the higher cortical regions, yet the mechanisms underlying such maladaptive cortical plasticity remain unclear. Here, we show that in male mice, structural and functional changes in the primary somatosensory cortex (S1) caused by peripheral nerve injury require neuron-microglial signaling within the local circuit. Following peripheral nerve injury, microglia in the S1 maintain ramified morphology and normal density but up-regulate the mRNA expression of brain-derived neurotrophic factor (BDNF). Using in vivo two-photon imaging and Cx3cr1CreER;Bdnfflox mice, we show that conditional knockout of BDNF from microglia prevents nerve injury–induced synaptic remodeling and pyramidal neuron hyperactivity in the S1, as well as pain hypersensitivity in mice. Importantly, S1-targeted removal of microglial BDNF largely recapitulates the beneficial effects of systemic BDNF depletion on cortical plasticity and allodynia. Together, these findings reveal a pivotal role of cerebral microglial BDNF in somatosensory cortical plasticity and pain hypersensitivity.

scholarly journals Comparison of MR findings of acute traumatic peripheral nerve injury and acute compressive neuropathy in a rat model

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0240911
Author(s):  
Bo Ra Kim ◽  
Dong-Ho Ha ◽  
Jong Kuk Kim ◽  
Young Hee Kim
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Distal Portion ◽  
Crush Injury ◽  
Compression Injury ◽  
Mr Neurography ◽  
Injury Site ◽  
Compressive Neuropathy ◽  
Injury Group

Purpose The treatment strategy is different for acute traumatic peripheral nerve injury and acute compressive neuropathy. This study aimed to compare magnetic resonance imaging (MRI) features of acute traumatic peripheral nerve injury and acute compressive neuropathy in a rat model. Materials and methods Twenty female Sprague-Dawley rats were divided into two groups. In the crush injury group (n = 10), the unilateral sciatic nerve was crushed using forceps to represent acute traumatic peripheral nerve injury. In the compression injury group (n = 10), the unilateral sciatic nerve was ligated using silk to represent acute compressive neuropathy. The MRI of eight rats from each group were acquired on postoperative days 3 and 10. Fat-suppressed T2-weighted images were acquired. Changes in the injured nerve were divided into three grades. A Fisher’s exact test was used to compare the changes in the nerves of the two groups. Histological staining and a western blot analysis were performed on one rat in each group on day 3. Neurofilament, myelin basic protein (MBP), and p75NTR staining were performed. Expression of neurofilament, MBP, p75NTR, and c-jun was evaluated by western blot analysis. Results MR neurography revealed substantial nerve changes in the compression injury group compared with the crush injury group at two-time points (p = 0.001 on day 3, p = 0.026 on day 10). The histopathological analysis indicated the destruction of the axon and myelin, mainly at the injury site and the distal portion of the injury in the crush injury group. It was prominent in the proximal portion, the injury site, and the distal portion of the injury in the compression injury group. The degree of axonal and myelin destruction was more pronounced in the compression injury group than in the crush injury group. Conclusion MR neurography showed prominent and long-segmental changes associated with the injured nerve in acute compressive neuropathy compared with acute traumatic peripheral nerve injury.

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