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Michel Kliot - One of the best experts on this subject based on the ideXlab platform.
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Visualization of Nerve fibers and their relationship to peripheral Nerve Tumors by diffusion tensor imaging.
Neurosurgical focus, 2015Co-Authors: Tene A. Cage, Esther L. Yuh, Stephanie W. Hou, Harjus Birk, Neil G. Simon, Roger S. Noss, Anuradha Rao, Cynthia Chin, Michel KliotAbstract:OBJECT The majority of growing and/or symptomatic peripheral Nerve Tumors are schwannomas and neurofibromas. They are almost always benign and can usually be resected while minimizing motor and sensory deficits if approached with the proper expertise and techniques. Intraoperative electrophysiological stimulation and recording techniques allow the surgeon to map the surface of the Tumor in an effort to identify and thus avoid damaging functioning Nerve fibers. Recently, MR diffusion tensor imaging (DTI) techniques have permitted the visualization of axons, because of their anisotropic properties, in peripheral Nerves. The object of this study was to compare the distribution of Nerve fibers as revealed by direct electrical stimulation with that seen on preoperative MR DTI. METHODS The authors conducted a retrospective chart review of patients with a peripheral Nerve or Nerve root Tumor between March 2012 and January 2014. Diffusion tensor imaging and intraoperative data had been prospectively collected for patients with peripheral Nerve Tumors that were resected. Preoperative identification of the Nerve fiber location in relation to the Nerve Tumor surface as seen on DTI studies was compared with the Nerve fiber's intraoperative localization using electrophysiological stimulation and recordings. RESULTS In 23 patients eligible for study there was good correlation between Nerve fiber location on DTI and its anatomical location seen intraoperatively. Diffusion tensor imaging demonstrated the relationship of Nerve fibers relative to the Tumor with 95.7% sensitivity, 66.7% specificity, 75% positive predictive value, and 93.8% negative predictive value. CONCLUSIONS Preoperative DTI techniques are useful in helping the peripheral Nerve surgeon to both determine the risks involved in resecting a Nerve Tumor and plan the safest surgical approach.
Luca Padua - One of the best experts on this subject based on the ideXlab platform.
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US diagnosis of sciatic Nerve Tumor proximal to gluteal fold
Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 2014Co-Authors: Giuseppe Granata, Roberto Gasparotti, Ilaria Paolasso, Carmen Erra, H. Tsukamoto, Luca PaduaAbstract:High-resolution ultrasound (US) is a helpful technique for the evaluation of peripheral Nerves. It is now well accepted that especially in Nerve mononeuropaties the combination of morphological data, obtained through US, and functional data, obtained through electrophysiology, is the appropriate way to reach the best diagnosis including information for therapeutical decision. Literature data show that US may crucially influence diagnosis and clinical care in Nerve Tumors [1, 2]. However, Nerve US has some limitations. In particular the visualization of deep Nerves is difficult, especially in overweight people. This is the case of proximal part of sciatic Nerve that is commonly detectable only distal to the gluteal fold. We report on a 48-year-old woman complaining of pain and electric shocks radiated to sciatic course and trigger point in the right gluteal region. Clinical examination showed only mild right extensor hallucis longus weakness. Needle electromyography of tibialis anterior, gastrocnemius, peroneus longus was normal and mild chronic neurogenic recruitment was observed in extensor hallucis longus. It was suspected a right L5 radiculopathy but magnetic resonance (MR) showed only a mild L5–S1 bulging that was not considered the cause of symptoms. US of sciatic Nerve was then performed although the trigger point was in a region where usually sciatic Nerve is not detectable, proximally to the gluteal fold. US was performed using a linear 6–10 and 10–18 MHz transducer and sciatic Nerve was bilaterally evaluated in distal–proximal direction starting from the popliteal fossa. Right sciatic Nerve was detectable along all its course, even proximally to the gluteal fold although with no optimal visualization. At the middle-third of the gluteus a fusiform hypoechoic increase of Nerve volume was found. The maximum longitudinal diameter was 2.5 cm and maximum antero-posterior diameter was 2.0 cm (max cross-sectional area 4.5 cm). An accurate evaluation of the US video clip suggested that the mass raised from lateral fascicles sparing and dislocating remaining medial fascicles (Fig. 1a, b). US and clinical data suggested a sciatic Nerve Tumor, likely a schwannoma. MR confirmed the lesion showing a partially preserved fascicular structure, suggesting a schwannoma (Fig. 1c–f). Surgical excision was refused by the patient and US monitoring planned. Our case report confirms the usefulness of US in the diagnosis of Nerve Tumors. US is not able to clearly differentiate the type of Nerve Tumor but can provide useful information to discriminate between the two main types, schwannoma or neurofibroma [3–5]. Schwannoma typically displaces the Nerve fascicles and generally is positioned eccentrically to the affected Nerve segment. Another typical feature especially of large lesions is the presence of hyperechoic calcifications and internal degenerative cystic foci. On the other side neurofibroma presents as a concentric lesion that does not displace the fascicular elements of the Nerve but interferes with them (usually fascicles are not detectable). Another typical sonographic feature of this kind of Tumor is the so-called ‘‘target sign’’ (layered aspect, with a hyperechoic centre and a peripheral hypoechoic rim, best seen on transverse scans) [6]. Usually G. Granata (&) I. Paolasso C. Erra H. Tsukamoto L. Padua Institute of Neurology, Catholic University of Sacred Heart, Largo F. Vito 1, 00168 Rome, Italy e-mail: granata.gius@gmail.com
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P616: Neurophysiology and ultrasound in diagnosis of isolated peripheral Nerve Tumors. Literature revision and personal experience
Clinical Neurophysiology, 2014Co-Authors: Daniele Coraci, Carmen Erra, Valter Santilli, P. De Franco, Luca PaduaAbstract:Our work shows the association of neurophysiology and ultrasound in the assessment of peripheral Nerve Tumors. In these cases, neurophysiologic examination presents an important role to define the possible lack of function of the Nerve. Ultrasonography allows us to visualize the peripheral Nerves and underline the morphologic changes in Nerve structure. We present a literature revision about ultrasound in peripheral Nerve Tumor study and a collection of 10 cases where the combined use of clinic, neurophysiology and ultrasound guided the diagnostic process of Nerve Tumors. All the patients presented a clinic pattern of Nerve involvement and everyone was evaluated with neurophysiology which confirmed a mononeuropathy, but without the possibility of a sure diagnosis. The following ultrasound evaluation allowed to visualize a focal lesion, compatible with a Nerve Tumor. These cases show that neurophysiology and ultrasound together contribute in diagnosis of peripheral Nerve Tumors. Ultrasonography is not able to certainly define the type of Tumor, but it gives suggestions about discrimination between schwannoma and neurofibroma. Nerve ultrasound is useful in the assessment of peripheral Nerve Tumors.
John A. Carrino - One of the best experts on this subject based on the ideXlab platform.
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anatomic mr imaging and functional diffusion tensor imaging of peripheral Nerve Tumors and Tumorlike conditions
American Journal of Neuroradiology, 2013Co-Authors: Avneesh Chhabra, Rashmi S. Thakkar, Ahmet Höke, Allan J. Belzberg, Gustav Andreisek, Majid Chalian, Jaishri O Blakeley, Gaurav K Thawait, John A. CarrinoAbstract:BACKGROUND AND PURPOSE: A number of benign and malignant peripheral Nerve Tumor and Tumorlike conditions produce similar imaging features on conventional anatomic MR imaging. Functional MR imaging using DTI can increment the diagnostic performance in differentiation of these lesions. Our aim was to evaluate the role of 3T anatomic MR imaging and DTI in the characterization of peripheral Nerve Tumor and Tumorlike conditions. MATERIALS AND METHODS: Twenty-nine patients (13 men, 16 women; mean age, 41 ± 18 years; range, 11–83 years) with a Nerve Tumor or Tumorlike condition (25 benign, 5 malignant) underwent 3T MR imaging by using anatomic ( n = 29), functional diffusion, DWI ( n = 21), and DTI ( n = 24) techniques. Images were evaluated for image quality (3-point scale), ADC of the lesion, tractography, and fractional anisotropy of Nerves with interobserver reliability in ADC and FA measurements. RESULTS: No significant differences were observed in age (benign, 40 ± 18 versus malignant, 45 ± 19 years) and sex (benign, male/female = 12:12 versus malignant, male/female = 3:2) ( P > .05). All anatomic (29/29, 100%) MR imaging studies received “good” quality; 20/21 (95%) DWI and 21/24 (79%) DTI studies received “good” quality. ADC of benign lesions (1.848 ± 0.40 × 10 −3 mm 2 /s) differed from that of malignant lesions (0.900 ± 0.25 × 10 −3 mm 2 /s, P P > .05). FA of involved Nerves was lower than that in contralateral healthy Nerves ( P P > .05), with excellent intermethod reliability (ICC = 0.943 [95% CI, 0.836–0.980]). Tractography differences were observed in benign and malignant lesions. CONCLUSIONS: 3T MR imaging and DTI are valuable methods for anatomic and functional evaluation of peripheral Nerve lesions with excellent interobserver reliability. While tractography and low FA provide insight into neural integrity, low diffusivity values indicate malignancy in neural masses.
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Sciatic Nerve Tumor and Tumor-like lesions—uncommon pathologies
Skeletal Radiology, 2012Co-Authors: Vibhor Wadhwa, Rashmi S. Thakkar, Nicholas Maragakis, Ahmet Höke, Charlotte J. Sumner, Thomas E. Lloyd, John A. Carrino, Allan J. Belzberg, Avneesh ChhabraAbstract:Sciatic Nerve mass-like enlargement caused by peripheral Nerve sheath Tumors or neurocutaneous syndromes such as neurofibromatosis or schwannomatosis has been widely reported. Other causes of enlargement, such as from perineuroma, fibromatosis, neurolymphoma, amyloidosis, endometriosis, intraneural ganglion cyst, Charcot–Marie–Tooth disease, and chronic inflammatory demyelinating polyneuropathy are relatively rare. High-resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss normal anatomy of the sciatic Nerve and MRI findings of the above-mentioned lesions.
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sciatic Nerve Tumor and Tumor like lesions uncommon pathologies
Skeletal Radiology, 2012Co-Authors: Vibhor Wadhwa, Rashmi S. Thakkar, Nicholas Maragakis, Ahmet Höke, Charlotte J. Sumner, Thomas E. Lloyd, John A. Carrino, Allan J. Belzberg, Avneesh ChhabraAbstract:Sciatic Nerve mass-like enlargement caused by peripheral Nerve sheath Tumors or neurocutaneous syndromes such as neurofibromatosis or schwannomatosis has been widely reported. Other causes of enlargement, such as from perineuroma, fibromatosis, neurolymphoma, amyloidosis, endometriosis, intraneural ganglion cyst, Charcot–Marie–Tooth disease, and chronic inflammatory demyelinating polyneuropathy are relatively rare. High-resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss normal anatomy of the sciatic Nerve and MRI findings of the above-mentioned lesions.
Tene A. Cage - One of the best experts on this subject based on the ideXlab platform.
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Visualization of Nerve fibers and their relationship to peripheral Nerve Tumors by diffusion tensor imaging.
Neurosurgical focus, 2015Co-Authors: Tene A. Cage, Esther L. Yuh, Stephanie W. Hou, Harjus Birk, Neil G. Simon, Roger S. Noss, Anuradha Rao, Cynthia Chin, Michel KliotAbstract:OBJECT The majority of growing and/or symptomatic peripheral Nerve Tumors are schwannomas and neurofibromas. They are almost always benign and can usually be resected while minimizing motor and sensory deficits if approached with the proper expertise and techniques. Intraoperative electrophysiological stimulation and recording techniques allow the surgeon to map the surface of the Tumor in an effort to identify and thus avoid damaging functioning Nerve fibers. Recently, MR diffusion tensor imaging (DTI) techniques have permitted the visualization of axons, because of their anisotropic properties, in peripheral Nerves. The object of this study was to compare the distribution of Nerve fibers as revealed by direct electrical stimulation with that seen on preoperative MR DTI. METHODS The authors conducted a retrospective chart review of patients with a peripheral Nerve or Nerve root Tumor between March 2012 and January 2014. Diffusion tensor imaging and intraoperative data had been prospectively collected for patients with peripheral Nerve Tumors that were resected. Preoperative identification of the Nerve fiber location in relation to the Nerve Tumor surface as seen on DTI studies was compared with the Nerve fiber's intraoperative localization using electrophysiological stimulation and recordings. RESULTS In 23 patients eligible for study there was good correlation between Nerve fiber location on DTI and its anatomical location seen intraoperatively. Diffusion tensor imaging demonstrated the relationship of Nerve fibers relative to the Tumor with 95.7% sensitivity, 66.7% specificity, 75% positive predictive value, and 93.8% negative predictive value. CONCLUSIONS Preoperative DTI techniques are useful in helping the peripheral Nerve surgeon to both determine the risks involved in resecting a Nerve Tumor and plan the safest surgical approach.
Allan J. Belzberg - One of the best experts on this subject based on the ideXlab platform.
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anatomic mr imaging and functional diffusion tensor imaging of peripheral Nerve Tumors and Tumorlike conditions
American Journal of Neuroradiology, 2013Co-Authors: Avneesh Chhabra, Rashmi S. Thakkar, Ahmet Höke, Allan J. Belzberg, Gustav Andreisek, Majid Chalian, Jaishri O Blakeley, Gaurav K Thawait, John A. CarrinoAbstract:BACKGROUND AND PURPOSE: A number of benign and malignant peripheral Nerve Tumor and Tumorlike conditions produce similar imaging features on conventional anatomic MR imaging. Functional MR imaging using DTI can increment the diagnostic performance in differentiation of these lesions. Our aim was to evaluate the role of 3T anatomic MR imaging and DTI in the characterization of peripheral Nerve Tumor and Tumorlike conditions. MATERIALS AND METHODS: Twenty-nine patients (13 men, 16 women; mean age, 41 ± 18 years; range, 11–83 years) with a Nerve Tumor or Tumorlike condition (25 benign, 5 malignant) underwent 3T MR imaging by using anatomic ( n = 29), functional diffusion, DWI ( n = 21), and DTI ( n = 24) techniques. Images were evaluated for image quality (3-point scale), ADC of the lesion, tractography, and fractional anisotropy of Nerves with interobserver reliability in ADC and FA measurements. RESULTS: No significant differences were observed in age (benign, 40 ± 18 versus malignant, 45 ± 19 years) and sex (benign, male/female = 12:12 versus malignant, male/female = 3:2) ( P > .05). All anatomic (29/29, 100%) MR imaging studies received “good” quality; 20/21 (95%) DWI and 21/24 (79%) DTI studies received “good” quality. ADC of benign lesions (1.848 ± 0.40 × 10 −3 mm 2 /s) differed from that of malignant lesions (0.900 ± 0.25 × 10 −3 mm 2 /s, P P > .05). FA of involved Nerves was lower than that in contralateral healthy Nerves ( P P > .05), with excellent intermethod reliability (ICC = 0.943 [95% CI, 0.836–0.980]). Tractography differences were observed in benign and malignant lesions. CONCLUSIONS: 3T MR imaging and DTI are valuable methods for anatomic and functional evaluation of peripheral Nerve lesions with excellent interobserver reliability. While tractography and low FA provide insight into neural integrity, low diffusivity values indicate malignancy in neural masses.
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Sciatic Nerve Tumor and Tumor-like lesions—uncommon pathologies
Skeletal Radiology, 2012Co-Authors: Vibhor Wadhwa, Rashmi S. Thakkar, Nicholas Maragakis, Ahmet Höke, Charlotte J. Sumner, Thomas E. Lloyd, John A. Carrino, Allan J. Belzberg, Avneesh ChhabraAbstract:Sciatic Nerve mass-like enlargement caused by peripheral Nerve sheath Tumors or neurocutaneous syndromes such as neurofibromatosis or schwannomatosis has been widely reported. Other causes of enlargement, such as from perineuroma, fibromatosis, neurolymphoma, amyloidosis, endometriosis, intraneural ganglion cyst, Charcot–Marie–Tooth disease, and chronic inflammatory demyelinating polyneuropathy are relatively rare. High-resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss normal anatomy of the sciatic Nerve and MRI findings of the above-mentioned lesions.
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sciatic Nerve Tumor and Tumor like lesions uncommon pathologies
Skeletal Radiology, 2012Co-Authors: Vibhor Wadhwa, Rashmi S. Thakkar, Nicholas Maragakis, Ahmet Höke, Charlotte J. Sumner, Thomas E. Lloyd, John A. Carrino, Allan J. Belzberg, Avneesh ChhabraAbstract:Sciatic Nerve mass-like enlargement caused by peripheral Nerve sheath Tumors or neurocutaneous syndromes such as neurofibromatosis or schwannomatosis has been widely reported. Other causes of enlargement, such as from perineuroma, fibromatosis, neurolymphoma, amyloidosis, endometriosis, intraneural ganglion cyst, Charcot–Marie–Tooth disease, and chronic inflammatory demyelinating polyneuropathy are relatively rare. High-resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss normal anatomy of the sciatic Nerve and MRI findings of the above-mentioned lesions.
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harvey cushing s innovative attempt at xenotransplanting a rabbit spinal cord in a patient after resection of a peripheral Nerve Tumor in 1902
Neurosurgery, 2011Co-Authors: Hasan A Zaidi, Courtney Pendleton, Allan J. Belzberg, Gustavo Pradilla, Aaron A Cohengadol, Alfredo QuinoneshinojosaAbstract:OBJECTIVE: A review of Harvey Cushing's surgical cases at Johns Hopkins Hospital revealed new information about his early work using Nerve xenografts to repair peripheral Nerve injuries. METHODS: The Johns Hopkins Hospital surgical records from 1896 to 1912 were reviewed. A single case in which Cushing used a xenograft to repair a peripheral Nerve defect was selected for further study. RESULTS: In August 1902, a 23-year-old woman presented with tingling and numbness in her left foot and focal tenderness in the popliteal region. Cushing performed an exploratory operation, revealing an encapsulated Tumor originating from the internal popliteal Nerve. After resecting the segment of involved Nerve, Cushing harvested the spinal cord from a rabbit and used it to span the 18-cm defect. At a 5-month postoperative follow-up, according to Cushing's clinical notes, the patient had partially regained some sensation in her leg and foot. Seven months later, the patient presented with a local Tumor recurrence, and her leg was amputated. An examination of the amputated specimen demonstrated that the xenograft was still intact without gross evidence of xenograft rejection. CONCLUSION: Despite its questionable functional success, we report a previously unpublished operative case by Harvey Cushing in which a rabbit spinal cord was transplanted into a human to bridge a sciatic Nerve gap. This sheds light on the potential for animal tissue as a source for the treatment of neurological disease in humans.