Quantitative assessment of sciatic nerve changes in Charcot–Marie–Tooth type 1A patients using magnetic resonance neurography

10092 Background: Oxaliplatin induced peripheral neuropathy (OXA-PNP) is a frequent side effect of oxaliplatin containing chemotherapy protocols. It is commonly assessed clinically via physical examination and patient reported symptoms. Research has been impeded by the lack of objective tests to quantify OXA-PNP. Neurophysiological examination is time-consuming and can only cover a selected part of the examined nerve. The aim of this study was to investigate in-vivo morphological correlates of OXA-PNP by magnetic resonance neurography (MRN). Methods: 20 patients with mild to moderate OXA-PNP and 20 matched controls were prospectively enrolled. All patients underwent a detailed neurophysiology examination prior to neuroimaging. A standardized MRN imaging protocol at 3.0 Tesla with large-coverage included the lumbosacral plexus, as well as both sciatic nerves and their branches using T2-weighted fat-saturated sequences at high resolution. Qualitative evaluation of sciatic, tibial, and peroneal nerves were performed by two readers regarding the presence, degree, and distribution of nerve lesions. Quantitative assessment included volumetry of the dorsal root ganglia (DRG) and sciatic nerve normalized T2 (nT2) signal and caliber. Results: Significant DRG hypertrophy in OXA-PNP patients (207.3±47.7mm3 vs. 153.0±47.1mm3 in controls, p = 0.001) was found as morphological correlate of the sensory neuronopathy. Peripheral nerves only exhibited slight morphological alterations qualitatively. Quantitatively, sciatic nerve caliber was unchanged (26.0±5.1mm2 vs. 27.4±7.4mm2, p = 0.19) while sciatic nerve nT2 signal was slightly and non-significantly elevated in patients (1.32±0.22 vs. 1.22±0.26, p = 0.19). Conclusions: OXA-PNP leads to morphological correlates that can be detected in-vivo by MRN. Significant hypertrophy of the DRG was observed, a phenomenon which has not been described in OXA-PNP previously. DRG volume should be investigated as a biomarker in other sensory peripheral neuropathies and ganglionopathies as well as in studies evaluating neuroprotective strategies for OXA-PNP.

Download Full-text

Workup and Management of Persistent Neuralgia following Nerve Block

Case Reports in Anesthesiology ◽

10.1155/2016/9863492 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6

Author(s):

Paul David Weyker ◽

Christopher Allen-John Webb ◽

Thoha M. Pham

Keyword(s):

Magnetic Resonance ◽

Sciatic Nerve ◽

Nerve Block ◽

Magnetic Resonance Neurography ◽

Nerve Blocks ◽

Duration Of Symptoms ◽

Peripheral Nerve Blocks ◽

Nonopioid Analgesics ◽

Sciatic Nerves ◽

Neurological Injuries

Neurological injuries following peripheral nerve blocks are a relatively rare yet potentially devastating complication depending on the type of lesion, affected extremity, and duration of symptoms. Medical management continues to be the treatment modality of choice with multimodal nonopioid analgesics as the cornerstone of this therapy. We report the case of a 28-year-old man who developed a clinical common peroneal and lateral sural cutaneous neuropathy following an uncomplicated popliteal sciatic nerve block. Workup with electrodiagnostic studies and magnetic resonance neurography revealed injury to both the femoral and sciatic nerves. Diagnostic studies and potential mechanisms for nerve injury are discussed.

Download Full-text

Quantitative assessment of diabetic amyotrophy using magnetic resonance neurography—a case-control analysis

European Radiology ◽

10.1007/s00330-019-06162-3 ◽

2019 ◽

Vol 29 (11) ◽

pp. 5910-5919 ◽

Cited By ~ 2

Author(s):

Rocco Hlis ◽

Feng Poh ◽

Meredith Bryarly ◽

Yin Xi ◽

Avneesh Chhabra

Keyword(s):

Magnetic Resonance ◽

Quantitative Assessment ◽

Case Control ◽

Control Analysis ◽

Magnetic Resonance Neurography ◽

Diabetic Amyotrophy ◽

Case Control Analysis

Download Full-text

High resolution (3T) magnetic resonance neurography of the sciatic nerve

Radiología (English Edition) ◽

10.1016/j.rxeng.2012.04.001 ◽

2013 ◽

Vol 55 (3) ◽

pp. 195-202

Author(s):

C. Cejas ◽

M. Aguilar ◽

L. Falcón ◽

N. Caneo ◽

M.C. Acuña

Keyword(s):

Magnetic Resonance ◽

High Resolution ◽

Sciatic Nerve ◽

Magnetic Resonance Neurography

Download Full-text

Sciatic neuropathy: findings on magnetic resonance neurography

Radiologia Brasileira ◽

10.1590/0100-3984.2015.0205 ◽

2017 ◽

Vol 50 (3) ◽

pp. 190-196 ◽

Cited By ~ 4

Author(s):

Paulo Moraes Agnollitto ◽

Marcio Wen King Chu ◽

Marcelo Novelino Simão ◽

Marcello Henrique Nogueira-Barbosa

Keyword(s):

Magnetic Resonance ◽

Sciatic Nerve ◽

Diagnostic Imaging ◽

Peripheral Nerves ◽

Lower Limbs ◽

Detailed Knowledge ◽

Magnetic Resonance Neurography ◽

Sciatic Neuropathy ◽

Common Causes ◽

Long Course

Abstract Injuries of the sciatic nerve are common causes of pain and limitation in the lower limbs. Due to its particular anatomy and its long course, the sciatic nerve is often involved in diseases of the pelvis or leg. In recent years, magnetic resonance neurography has become established as an important tool for the study of peripheral nerves and can be widely applied to the study of the sciatic nerve. Therefore, detailed knowledge of its anatomy and of the most prevalent diseases affecting it is essential to maximizing the accuracy of diagnostic imaging.

Download Full-text

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

Journal of Neurosurgery ◽

10.3171/jns.2002.96.4.0755 ◽

2002 ◽

Vol 96 (4) ◽

pp. 755-759 ◽

Cited By ~ 62

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.

Download Full-text

Early abnormalities in sciatic nerve function and structure in a rat model of Charcot-Marie-Tooth type 1A disease

Experimental Neurology ◽

10.1016/j.expneurol.2004.07.008 ◽

2004 ◽

Vol 190 (1) ◽

pp. 213-223 ◽

Cited By ~ 14

Author(s):

Marina Grandis ◽

Massimo Leandri ◽

Tiziana Vigo ◽

Michele Cilli ◽

Michael W. Sereda ◽

...

Keyword(s):

Sciatic Nerve ◽

Rat Model ◽

Nerve Function ◽

Charcot Marie Tooth ◽

Tooth Type

Download Full-text

Magnetic resonance neurography evaluation of chronic extraspinal sciatica after remote proximal hamstring injury: a preliminary retrospective analysis

Journal of Neurosurgery ◽

10.3171/2014.4.jns13940 ◽

2014 ◽

Vol 121 (2) ◽

pp. 408-414 ◽

Cited By ~ 11

Author(s):

Matthew D. Bucknor ◽

Lynne S. Steinbach ◽

David Saloner ◽

Cynthia T. Chin

Keyword(s):

Magnetic Resonance ◽

Soft Tissue ◽

Sciatic Nerve ◽

Hamstring Tendon ◽

Tendon Injury ◽

Ischial Tuberosity ◽

Magnetic Resonance Neurography ◽

Cross Sectional ◽

Tissue Abnormalities ◽

Proximal Hamstring

Object Extraspinal sciatica can present unique challenges in clinical diagnosis and management. In this study, the authors evaluated qualitative and quantitative patterns of sciatica-related pathology at the ischial tuberosity on MR neurography (MRN) studies performed for chronic extraspinal sciatica. Methods Lumbosacral MRN studies obtained in 14 patients at the University of California, San Francisco between 2007 and 2011 were retrospectively reviewed. The patients had been referred by neurosurgeons or neurologists for chronic unilateral sciatica (≥ 3 months), and the MRN reports described asymmetrical increased T2 signal within the sciatic nerve at the level of the ischial tuberosity. MRN studies were also performed prospectively in 6 healthy volunteers. Sciatic nerve T2 signal intensity (SI) and cross-sectional area at the ischial tuberosity were calculated and compared between the 2 sides in all 20 subjects. The same measurements were also performed at the sciatic notch as an internal reference. Adjacent musculoskeletal pathology was compared between the 2 sides in all subjects. Results Seven of the 9 patients for whom detailed histories were available had a specific history of injury or trauma near the proximal hamstring preceding the onset of sciatica. Eight of the 14 patients also demonstrated soft-tissue abnormalities adjacent to the proximal hamstring origin. The remaining 6 had normal muscles, tendons, and marrow in the region of the ischial tuberosity. There was a significant difference in sciatic nerve SI and size between the symptomatic and asymptomatic sides at the level of the ischial tuberosity, with a mean adjusted SI of 1.38 compared with 1.00 (p < 0.001) and a mean cross-sectional nerve area of 0.66 versus 0.54 cm2 (p = 0.002). The control group demonstrated symmetrical adjusted SI and sciatic nerve size. Conclusions This study suggests that chronic sciatic neuropathy can be seen at the ischial tuberosity in the setting of prior proximal hamstring tendon injury or adjacent soft-tissue abnormalities. Because hamstring tendon injury as a cause of chronic sciatica remains a diagnosis of exclusion, this distinct category of patients has not been described in the radiographic literature and merits special attention from clinicians and radiologists in the management of extraspinal sciatica. Magnetic resonance neurography is useful for evaluating chronic sciatic neuropathy both qualitatively and quantitatively, particularly in patients for whom electromyography and traditional MRI studies are unrevealing.

Download Full-text