Magnetic resonance neurography of peripheral nerve following experimental crush injury, and correlation with functional deficit

2002 ◽  
Vol 96 (4) ◽  
pp. 755-759 ◽  
Author(s):  
Simon A. Cudlip ◽  
Franklyn A. Howe ◽  
John R. Griffiths ◽  
B. Anthony Bell
Keyword(s):  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Nerve Crush ◽  
Content Type ◽  
Functional Deficit ◽  
Track Analysis ◽  
Fine Print

Object. In a number of clinical studies magnetic resonance (MR) neurography has been used to examine patients with peripheral nerve damage, but little is understood about the sequence of imaging changes following nerve injuries, and how they correlate with functional deficit. The goal of this study was to further understanding of these changes and their implications. Methods. Using the rat sciatic nerve crush model, the sciatic nerve was imaged at intervals over 70 days in 12 rats. Sham-operated contralateral nerves served as controls. A 4.7-tesla MR imager with a custom-made surface coil was used. The T2 maps were calculated from images obtained at four echo times and from regions of interest designated on the nerve at three sites. Walking-track analysis was performed at the same intervals as imaging. Magnetic resonance neurography revealed a mean T2 of normal sciatic nerve of 36 msec (standard deviation [SD] 1.2 msec). Crushed nerves demonstrated a sequence of changes in signal intensity that were maximal at 14 days, with a mean T2 of 64 msec (SD 5.2 msec), then falling to a T2 of 53 msec (SD 3.7 msec). Sham-operated nerves had a short and nonsustained rise in signal at 7 days. Walking-track analysis revealed maximum deficit immediately postinjury, with an improvement in function approaching that of control nerves at 30 days. Conclusions. In this study the authors demonstrate that quantitative assessment of nerve signals with MR neurography allows the sequence of events following nerve crush injury to be followed in vivo, and that a return toward a normal signal correlates with functional improvement. Assessment of peripheral nerve injury in patients by using MR neurography has the potential to confirm acute nerve injury as well as to monitor the recovery process.

Application of magnetic resonance neurography in the evaluation of patients with peripheral nerve pathology

1996 ◽  
Vol 85 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Aaron G. Filler ◽  
Michel Kliot ◽  
Franklyn A. Howe ◽  
Cecil E. Hayes ◽  
Dawn E. Saunders ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Time Course ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Cross Sectional ◽  
Content Type ◽  
Direct Nerve ◽  
Fine Print

✓ Currently, diagnosis and management of disorders involving nerves are generally undertaken without images of the nerves themselves. The authors evaluated whether direct nerve images obtained using the new technique of magnetic resonance (MR) neurography could be used to make clinically important diagnostic distinctions that cannot be readily accomplished using existing methods. The authors obtained T2-weighted fast spin—echo fat-suppressed (chemical shift selection or inversion recovery) and T1-weighted images with planes parallel or transverse to the long axis of nerves using standard or phased-array coils in healthy volunteers and referred patients in 242 sessions. Longitudinal and cross-sectional fascicular images readily distinguished perineural from intraneural masses, thus predicting both resectability and requirement for intraoperative electrophysiological monitoring. Fascicle pattern and longitudinal anatomy firmly identified nerves and thus improved the safety of image-guided procedures. In severe trauma, MR neurography identified nerve discontinuity at the fascicular level preoperatively, thus verifying the need for surgical repair. Direct images readily demonstrated increased diameter in injured nerves and showed the linear extent and time course of image hyperintensity associated with nerve injury. These findings confirm and precisely localize focal nerve compressions, thus avoiding some exploratory surgery and allowing for smaller targeted exposures when surgery is indicated. Direct nerve imaging can demonstrate nerve continuity, distinguish intraneural from perineural masses, and localize nerve compressions prior to surgical exploration. Magnetic resonance neurography can add clinically useful diagnostic information in many situations in which physical examinations, electrodiagnostic tests, and existing image techniques are inconclusive.

Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment

2005 ◽  
Vol 2 (2) ◽  
pp. 99-115 ◽  
Author(s):  
Aaron G. Filler ◽  
Jodean Haynes ◽  
Sheldon E. Jordan ◽  
Joshua Prager ◽  
J. Pablo Villablanca ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Nerve Root ◽  
Piriformis Syndrome ◽  
Piriformis Muscle ◽  
Mr Neurography ◽  
Content Type ◽  
Interventional Mr ◽  
Interventional Mr Imaging ◽  
Fine Print

Object. Because lumbar magnetic resonance (MR) imaging fails to identify a treatable cause of chronic sciatica in nearly 1 million patients annually, the authors conducted MR neurography and interventional MR imaging in 239 consecutive patients with sciatica in whom standard diagnosis and treatment failed to effect improvement. Methods. After performing MR neurography and interventional MR imaging, the final rediagnoses included the following: piriformis syndrome (67.8%), distal foraminal nerve root entrapment (6%), ischial tunnel syndrome (4.7%), discogenic pain with referred leg pain (3.4%), pudendal nerve entrapment with referred pain (3%), distal sciatic entrapment (2.1%), sciatic tumor (1.7%), lumbosacral plexus entrapment (1.3%), unappreciated lateral disc herniation (1.3%), nerve root injury due to spinal surgery (1.3%), inadequate spinal nerve root decompression (0.8%), lumbar stenosis (0.8%), sacroiliac joint inflammation (0.8%), lumbosacral plexus tumor (0.4%), sacral fracture (0.4%), and no diagnosis (4.2%). Open MR—guided Marcaine injection into the piriformis muscle produced the following results: no response (15.7%), relief of greater than 8 months (14.9%), relief lasting 2 to 4 months with continuing relief after second injection (7.5%), relief for 2 to 4 months with subsequent recurrence (36.6%), and relief for 1 to 14 days with full recurrence (25.4%). Piriformis surgery (62 operations; 3-cm incision, transgluteal approach, 55% outpatient; 40% with local or epidural anesthesia) resulted in excellent outcome in 58.5%, good outcome in 22.6%, limited benefit in 13.2%, no benefit in 3.8%, and worsened symptoms in 1.9%. Conclusions. This Class A quality evaluation of MR neurography's diagnostic efficacy revealed that piriformis muscle asymmetry and sciatic nerve hyperintensity at the sciatic notch exhibited a 93% specificity and 64% sensitivity in distinguishing patients with piriformis syndrome from those without who had similar symptoms (p < 0.01). Evaluation of the nerve beyond the proximal foramen provided eight additional diagnostic categories affecting 96% of these patients. More than 80% of the population good or excellent functional outcome was achieved.

Peripheral nerve regeneration by transplantation of bone marrow stromal cell—derived Schwann cells in adult rats

2004 ◽  
Vol 101 (5) ◽  
pp. 806-812 ◽  
Author(s):  
Toshiro Mimura ◽  
Mari Dezawa ◽  
Hiroshi Kanno ◽  
Hajime Sawada ◽  
Isao Yamamoto
Keyword(s):  
Bone Marrow ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Peripheral Nerve Regeneration ◽  
Adult Rats ◽  
Content Type ◽  
Alternative Method ◽  
Fine Print

Object. Bone marrow stromal cells (BMSCs) can be induced to form Schwann cells by sequentially treating the cells with β-mercaptoethanol and retinoic acid, followed by forskolin and neurotrophic factors including heregulin. In this study the authors made artificial grafts filled with BMSC-derived Schwann cells (BMSC-DSCs) and transplanted them into the transected sciatic nerve in adult rats to evaluate the potential of BMSCs as a novel alternative method of peripheral nerve regeneration. Methods. The BMSC-DSCs were suspended in Matrigel and transferred into hollow fibers (12 mm in length), which were transplanted into the transected sciatic nerve in adult Wistar rats. Six months after cell transplantation, electrophysiological evaluation and walking track analysis were performed. Results of these studies showed significant improvement in motor nerve conduction velocity and sciatic nerve functional index in the BMSC-DSC—transplanted group compared with the control group (Matrigel graft only). Immunohistochemical study data demonstrated that transplanted BMSCs labeled with retrovirus green fluorescent protein were positive for P0 and myelin-associated glycoprotein and had reconstructed nodes of Ranvier and remyelinated regenerated nerve axons. The number of regenerated axons in the axial section of the central portion of the graft was significantly greater in the transplanted group. Although BMSCs can differentiate into several types of cells, tumor formation did not occur 6 months after engraftment. Conclusions. Results in this study indicate that BMSC-DSCs have great potential to promote regeneration of peripheral nerves. The artificial graft made with BMSC-DSCs represents an alternative method for the difficult reconstruction of a long distance gap in a peripheral nerve.

Magnetic resonance neurography studies of the median nerve before and after carpal tunnel decompression

2002 ◽  
Vol 96 (6) ◽  
pp. 1046-1051 ◽  
Author(s):  
Simon A. Cudlip ◽  
Franklyn A. Howe ◽  
Andrew Clifton ◽  
Martin S. Schwartz ◽  
B. Anthony Bell
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Surgical Decompression ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Content Type ◽  
Before And After ◽  
Tunnel Syndrome ◽  
Fine Print

Object. Recently developed novel MR protocols called MR neurography, which feature conspicuity for nerve, have been shown to demonstrate signal change and altered median nerve configuration in patients with median nerve compression. The postoperative course following median nerve decompression can be problematic, with persistent symptoms and abnormal results on electrophysiological studies for some months, despite successful surgical decompression. The authors undertook a prospective study in patients with carpal tunnel syndrome, correlating the clinical, electrophysiological, and MR neurography findings before and 3 months after surgery. Methods. Thirty patients and eight control volunteers were recruited to the study. The MR neurography consisted of axial and sagittal images (TR = 2000 msec, TE = 60 msec) obtained using a temporomandibular surface coil, fat saturation, and flow suppression. Maximum intensity projection images were used to follow the median nerve through the carpal tunnel in the sagittal plane. Magnetic resonance neurography in patients with carpal tunnel syndrome demonstrated proximal swelling (p < 0.001) and high signal change in the nerve, together with increased flattening ratios (p < 0.001) and loss of nerve signal in the distal carpal tunnel (p < 0.05). Sagittal images were very effective in precisely demonstrating the site and severity of nerve compression. After surgery, division of the flexor retinaculum could be demonstrated in all cases. Changes in nerve configuration, including increased cross-sectional area, and reduced flattening ratios (p < 0.001) were seen in all patients. In many cases restoration of the T2 signal intensity toward that of controls was seen in the median nerve in the distal carpal tunnel. Sagittal images were excellent in demonstrating expansion of the nerve at the site of surgical decompression. Conclusions. In this study the authors suggest that MR neurography is an effective means of both confirming compression of the median nerve and its successful surgical decompression in patients with carpal tunnel syndrome. This modality may prove useful in the assessment of unconfirmed or complex cases of carpal tunnel syndrome both before and after surgery.

Sciatic nerve sarcoidosis: utility of magnetic resonance peripheral nerve imaging and treatment with radiation therapy

2004 ◽  
Vol 100 (5) ◽  
pp. 956-959 ◽  
Author(s):  
Andrew T. Dailey ◽  
Matthew T. Rondina ◽  
Jeannette J. Townsend ◽  
Dennis C. Shrieve ◽  
J. Richard Baringer ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Mr Imaging ◽  
Peripheral Nerve ◽  
Foot Drop ◽  
Content Type ◽  
Nerve Imaging ◽  
Noncaseating Granulomas ◽  
Peripheral Nerve Imaging

✓ Sarcoidosis may involve both the central and peripheral nervous system, although peripheral nerve manifestations are usually seen late in the disease. In this report, the authors describe a case of sarcoidosis in a 22-year-old woman who presented with a foot drop. Although results of conventional lumbar magnetic resonance (MR) imaging were normal, MR peripheral nerve imaging of the thigh showed a mass in the sciatic nerve indicating tumor. An intraoperative biopsy sample revealed noncaseating granulomas consistent with sarcoid. The patient was treated with steroid drugs to control the manifestations of her disease but exhibited early signs of femoral bone necrosis, which required discontinuation of the steroids. She was then treated with local radiation therapy. At her 2-year follow-up visit the patient demonstrated relief of her symptoms and improvement on MR peripheral nerve imaging. This case demonstrates that sarcoidosis may present with peripheral nerve manifestations. The appearance of a diffusely swollen nerve on MR imaging should prompt clinicians to include sarcoidosis in the differential diagnosis and plan surgery accordingly. Patients who are not responsive to or who are unable to tolerate medical therapy may be treated with radiation therapy.

Characterization of genetically defined types of Charcot-Marie-Tooth neuropathies by using magnetic resonance neurography

2005 ◽  
Vol 102 (2) ◽  
pp. 242-245 ◽  
Author(s):  
Dilantha B. Ellegala ◽  
Stephen J. Monteith ◽  
David Haynor ◽  
Thomas D. Bird ◽  
Robert Goodkin ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Disease Progression ◽  
Nerve Conduction ◽  
Imaging Techniques ◽  
Case Series ◽  
Mr Neurography ◽  
Content Type ◽  
Charcot Marie Tooth ◽  
Conduction Velocities ◽  
Fine Print

Object. Charcot-Marie-Tooth (CMT) disease is a collection of related genetic disorders affecting peripheral nerves with an incidence of one in every 2500 individuals. A diagnosis of CMT disease has classically relied on a medical history, examination, and measurement of nerve conduction velocities. Advancements in genetic testing and magnetic resonance (MR) imaging techniques may provide clinicians with a more precise diagnostic armamentarium. The authors investigated MR neurography as a possible method to characterize CMT subtypes. Methods. The authors performed MR neurography to evaluate sciatic nerves in the mid-thigh area of seven patients with genetically defined subtypes of CMT, one patient with chronic inflammatory demylinating polyneuropathy, and one patient without neuropathy. The authors correlate their findings with normal nerve conduction velocities (NCVs) and present their results as a descriptive case series. Although MR neurography could not be used to distinguish subtypes of CMT disease on nerve area or fascicle number, it appears to characterize phenotypic features and disease progression noninvasively in patients with some subtypes. Conclusions. In conjunction with NCV measurements, MR neurography may be useful in the diagnosis of CMT neuropathies and in monitoring disease progression.

scholarly journals Magnetic Resonance Imaging as a Biomarker in Rodent Peripheral Nerve Injury Models Reveals an Age-Related Impairment of Nerve Regeneration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elisa Giorgetti ◽  
Michael Obrecht ◽  
Marie Ronco ◽  
Moh Panesar ◽  
Christian Lambert ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Magnetization Transfer Ratio ◽  
Sciatic Nerve Crush ◽  
Resonance Imaging ◽  
Nerve Crush

Abstract Assessment of myelin integrity in peripheral nerve injuries and pathologies has largely been limited to post-mortem analysis owing to the difficulty in obtaining biopsies without affecting nerve function. This is further encumbered  by the small size of the tissue and its location. Therefore, the development of robust, non-invasive methods is highly attractive. In this study, we used magnetic resonance imaging (MRI) techniques, including magnetization transfer ratio (MTR), to longitudinally and non-invasively characterize both the sciatic nerve crush and lysolecithin (LCP) demyelination models of peripheral nerve injury in rodents. Electrophysiological, gene expression and histological assessments complemented the extensive MRI analyses in young and aged animals. In the nerve crush model, MTR analysis indicated a slower recovery in regions distal to the site of injury in aged animals, as well as incomplete recovery at six weeks post-crush when analyzing across the entire nerve surface. Similar regional impairments were also found in the LCP demyelination model. This research underlines the power of MTR for the study of peripheral nerve injury in small tissues such as the sciatic nerve of rodents and contributes new knowledge to the effect of aging on recovery after injury. A particular advantage of the approach is the translational potential to human neuropathies.

Hand and Wrist Neuropathies: High-resolution Ultrasonography and MR Neurography

2021 ◽  
Vol 25 (02) ◽  
pp. 366-378
Author(s):  
Avneesh Chhabra ◽  
Raghu Ratakonda ◽  
Federico Zaottini ◽  
Riccardo Picasso ◽  
Carlo Martinoli
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Mr Neurography ◽  
Magnetic Resonance Neurography ◽  
Nerve Imaging ◽  
High Resolution Ultrasonography ◽  
Peripheral Nerve Imaging ◽  
Technical Considerations

AbstractHigh-resolution ultrasonography (US) and magnetic resonance neurography (MRN) have followed parallel paths for peripheral nerve imaging with little comparison of the two modalities. They seem equally effective to study a variety of neuropathies affecting large and small nerves in the wrist and hand. This article outlines the technical considerations of US and MRN and discusses normal and abnormal imaging appearances of hand and wrist nerves from etiologies such as entrapment, injury, tumor, and proximal and diffuse neuropathy, with specific case illustrations.

Spinal evoked response in the cat

1975 ◽  
Vol 43 (3) ◽  
pp. 329-336 ◽  
Author(s):  
Robert J. Sarnowski ◽  
Roger Q. Cracco ◽  
Harold B. Vogel ◽  
Fred Mount
Keyword(s):  
Spinal Cord ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Nerve Stimulation ◽  
Nerve Fibers ◽  
Evoked Responses ◽  
Afferent Pathways ◽  
Content Type ◽  
Sciatic Nerve Stimulation ◽  
Fine Print

✓ Summated evoked potentials to sciatic nerve stimulation were recorded from surface electrodes placed over the spine of cats. The response progressively increased in latency rostrally. It was largest and most complex in configuration in leads placed over the caudal spinal cord where sciatic nerve roots enter and begin to ascend the cord. The conduction velocity of the response was about 90 m/sec from rostral sacral to cervical regions. A comparison of surface-recorded evoked responses to stimulation of the sural nerve, the nerve to the medial head of the gastrocnemius muscle and the sciatic nerve suggest that the peripheral nerve fibers that mediate the response to sciatic nerve stimulation are primarily muscle nerve afferents. In surface, lamina, and durai recordings made over similar segmental levels, the response to sciatic nerve stimulation progressively increased in amplitude, duration, and wave form complexity from surface to depth. Failure of transmission across complete cord transections was demonstrated. Results in preparations with partial cord sections suggest that the surface-recorded response is mediated by multiple spinal cord afferent pathways which are situated primarily ipsilateral to the stimulated peripheral nerve. The data indicate that summated evoked responses arising in spinal cord afferent pathways can be recorded from surface-recording electrodes in cats. They suggest that this animal model may prove useful in the study of certain aspects of spinal cord pathology.

Intraneural perineurioma of the common peroneal nerve

2001 ◽  
Vol 94 (5) ◽  
pp. 811-815 ◽  
Author(s):  
Marta E. Heilbrun ◽  
Jay S. Tsuruda ◽  
Jeannette J. Townsend ◽  
M. Peter Heilbrun
Keyword(s):  
Magnetic Resonance ◽  
Surgical Management ◽  
Peroneal Nerve ◽  
Common Peroneal Nerve ◽  
Nerve Graft ◽  
Focal Lesion ◽  
Mr Neurography ◽  
Content Type ◽  
Intraneural Perineurioma ◽  
Fine Print

✓ Intraneural perineurioma, or localized hypertrophic mononeuropathy (LHM), is a focal lesion that produces a slowly progressive mononeuropathy in a peripheral nerve. The authors describe the clinical presentation, magnetic resonance (MR) neurography characteristics, and pathological characteristics of a perineurioma involving the peroneal nerve. Although there has been much debate surrounding the cause of this lesion, a literature review supports the argument that this is a neoplastic lesion, best referred to as intraneural perineurioma. Surgical management includes excision to prevent progression of palsy and placement of a nerve graft if clinically indicated. A 28-year-old woman presented with a 2-year history of progressive painless right peroneal nerve palsy. Magnetic resonance neurography revealed a right common peroneal nerve mass. At surgery, the mass was easily excised, leaving significant nerve fascicles intact. Intraoperative biopsy was not performed nor was a nerve graft placed. Pathological investigation demonstrated onion bulb—shaped whorls consistent with the appearance of intraneural perineurioma; immunochemical analysis confirmed the diagnosis. A review of the literature supports the argument that perineurioma, or LHM, is a neoplastic process, making “intraneural perineurioma” the most appropriate name. The authors also demonstrate the utility of MR neurography in the identification isolated nerve tumors and review the surgical management of this lesion.

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