Search

Blockage of the dorsal rami of the spinal nerves (DRSN) provides analgesia to the epaxial musculature area in dogs. However, techniques to block the DRSN at the cervical level in dogs haven't yet been investigated. This study aimed to study the anatomy of the cervical area, and to describe a new ultrasound (US)-guided inter-transversospinalis plane (ITP) block technique at the 5th cervical vertebrae (C5). Fourteen adult canine's cadavers were used in this blinded, cadaveric, experimental study. One cadaver for cryo-section, one for anatomical research and twelve to do an ITP injection using 0.3 mL/kg (HV) or 0.15 mL/kg (LV) of dye/contrast solution in each lateral at C5, followed by a computed tomography and anatomical dissection. The HV and LV groups stained a median (range) of 4.67 (3-6) and 3.67 (2-5) DRSN into the ITP, respectively (P<0.017). Stained DRSN in the splenius plane were found in nine (75%) HV and five (41.66%) LV injections, respectively. Spread in the epidural space was found in two dogs using LV. One of them was injected into the ITP (4.33 %) while the other one was done accidentally outside of this plane. The paravertebral spread was found in one injection of each group. There was no dye of the ventral rami of the spinal nerves. The US-guided ITP injection is feasible in dog cadavers. The LV injected just after the medial surface of the semispinalis capitis muscle is recommended to avoid a possible extensive epidural spread., Competing Interests: Declaration of competing interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Migraine is a primary headache defined as moderate-to-severe pain lasting 4 to 72 h, ranking 2nd among the disabling conditions for both genders regardless of the age and the greater occipital nerve (GON) block has been reported as an efficient treatment method for migraine. The present study aims to evaluate and compare the efficiency of the two methods of GON block, i.e., the ultrasound (US)-guided technique and the landmark-based technique., Method: Having a prospective and randomized design, the study assigned the patients with chronic migraine into two groups after which a neurologist performed landmark-based GON block in the first group while an algologist performed US-guided GON block in the second group. During the 3-month follow-up period, the number of days with pain, the duration of pain, the number of analgesic drugs taken in a month, and Visual Analogue Scale (VAS) scores were compared with the values ​​before treatment and at the 1st week, 1st month, and 3rd month after treatment., Results: US-guided GON block group included 34 patients while there were 32 patients in the landmark-based GON block group. US-guided GON block group showed significantly reduced VAS scores and frequency of attacks compared to the landmark-based GON block group at Month 1 after the procedure. After a 3-month follow-up period of the two groups, the frequency of attacks, analgesic intake and the duration of attacks were lower in both groups compared to the baseline. At 3-month follow-up, the mean of VAS scores decreased from 9,47 ± 2,69 to 4,67 ± 1,9 in US-guided GON block group and from 9,46 ± 0,98 to 7 ± 2,5 in the landmark-based GON block group., Conclusion: It was determined that both US-guided and landmark-based GON block were efficient techniques in patients with chronic migraine. US-guided GON block technique resulted in lower VAS scores, shorter durations of pain, lower frequencies of attack, and lower intake of analgesics compared to the landmark-based GON block technique., (© 2024. The Author(s).)

Chronic low back pain represents a leading cause of global disability, but can often be complex in etiology, with multiple pain generators contributing to patient discomfort. Anterior column low back pain involves the vertebral bodies and discs, with the vertebral body endplates now known to be a significant pain generator. Vertebrogenic low back pain secondary to irritation of the basivertebral nerve presents as axial discomfort, worse with forward flexion, and with concomitant Type I or II Modic changes on MRI. Minimally invasive basivertebral nerve radiofrequency ablation has emerged as an effective intervention for managing anterior column back pain. In this article, the authors present a comprehensive approach to identifying and treating vertebrogenic low back pain through image guided basivertebral nerve ablation. We outline the patient presentation and diagnostic workup, followed by a detailed procedural guide including equipment requirements, technique execution, and potential technical challenges and complications., Competing Interests: Declaration of competing interest John Smirniotopoulos, M.D. has been a consultant for Relievant, Boston Scientific, Avanos, and Zimvie., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Abstract: Migraine headaches are a significant global health concern, frequently managed with varying levels of success. Compression of the greater occipital nerve (GON) is hypothesized to contribute to pathology in some migraine patients, making extracranial nerve decompression surgery a potential intervention for refractory cases. However, accurate methods to image the GON along its tortuous course still need to be explored. Our group has developed magnetic resonance imaging sequences to track the GON. Yet, many challenges were met, which included navigating the GON's complex anatomy, understanding anatomical variants, and designing advanced magnetic resonance imaging sequences and coils to image the posterior scalp. Addressing these hurdles is vital to capture and understand GON pathology and guide potential interventions., Competing Interests: Conflicts of Interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Ultrasound-guided local anaesthesia is commonly used in veterinary orthopaedics for horses. This study aimed to assess an in vivo ultrasound technique for the medial branch of the dorsal branch of the cervical spinal nerves (MB-DBCSNs) in horses and compare the performance of clinicians with different experience levels. Ten healthy, skeletally mature horses were examined using radiographic and ultrasound (US) techniques in the cervical area (C3-C7). Four operators with varying experience conducted US examinations using a 10 MHz linear and 6 MHz curvilinear transducer over ten training sessions. The number of cervical nerves visualized was recorded. A chi-square test was used to analyse the impact of training, anatomical location, and operator experience on the identification of facet joints. Operator agreement was evaluated with Cohen's K test. The operators assessed 80 MB-DBCSNs, with radiographs and identified 70 healthy and 10 pathological facet joints. Training significantly improved visualization success, reaching 90% in later sessions. Cranial facet joints (C3-C5) were more frequently visualized (81%) than caudal ones (C5-C7) were (59%). US performance was influenced by the operator's skill, and agreement among operators ranged from slight to fair. Overall, practice improved cervical nerve visualization in vivo , particularly for cranial nerves, but the technique requires a long learning curve because of low levels of operator agreement.

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches., (© 2024. The Author(s).)

Purpose: MIXTURE is a simultaneous morphological and quantitative imaging sequence developed by Philips that provides high-resolution T2 maps from the imaged series. We aimed to compare the T2 maps of MIXTURE and SHINKEI-Quant (S-Q) in the cervical spine and to examine their usefulness in the functional diagnosis of cervical radiculopathy., Methods: Seven healthy male volunteers (mean age: 31 ± 8.0 years) and one patient with cervical disc herniation (44 years old, male) underwent cervical spine magnetic resonance imaging (MRI), and T2-mapping of each was performed simultaneously using MIXTURE and S-Q in consecutive sequences in one imaging session. The standard deviation (SD) of the T2 relaxation times and T2 relaxation times of the bilateral C6 and C7 dorsal root ganglia (DRG) and C5/6 level cervical cord on the same slice in the 3D T2-map of the cervical spine coronal section were measured and compared between MIXTURE and S-Q., Results: T2 relaxation times were significantly shorter in MIXTURE than in S-Q for all C6, C7 DRG, and C5/6 spinal cord measurements. The SD values of the T2 relaxation times were significantly lower for MIXTURE in the C5/6 spinal cord and C7 DRG. In cervical disc herniation, MRI showed multiple intervertebral compression lesions with spinal canal stenosis at C5/6 and disc herniation at C6/7., Conclusion: MIXTURE is useful for preoperative functional diagnosis. T2-mapping using MIXTURE can quantify cervical nerve roots more accurately than the S-Q method and is expected to be clinically applicable to cervical radiculopathy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Introduction: Acute cholecystitis is a painful inflammatory disease of the gallbladder. The Low Cervical-2 Plane Block is a retrolaminar block that targets the C3, C4, and C5 spinal nerves, which provide sensory innervation to the gallbladder, in order to potentially provide analgesia to patients with pain associated with acute cholecystitis., Methods: In this brief report, a softly embalmed cadaver was injected with a dye mixture bilaterally., Results: Subsequent cadaveric dissection revealed spread of the injectate deep to the prevertebral fascia to the C4 lamina on the right side and the C5 lamina on the left side. Also, diffusion of the anesthetic over the ligamenta flava could spread inferiorly and laterally to the spinal nerve roots of C3-C5 and thus potentially target the direct sensory innervation of the gallbladder., Conclusion: The Low Cervical-2 Plane Block is a potentially effective modality for treating intractable pain from acute cholecystitis. However, further cadaveric injections are needed to confirm the exact extent of spread of anesthetic. Clinical application of the Low Cervical-2 Plane Block in patients with acute cholecystitis is needed to establish the efficacy of this theoretical technique., Competing Interests: Declaration of Competing Interest None. The authors declare no competing interests. Support was provided solely from institutional and/or departmental sources., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: To investigate the injectate spread and nerve staining of ultrasound-guided erector spinae plane (ESP) injections at the thoracolumbar spine in canine cadavers., Study Design: Prospective, randomized, descriptive, anatomic study., Animals: A total of 15 canine cadavers., Methods: The location of the medial and lateral branches of the dorsal branches of the spinal nerves (DBSN) from the tenth thoracic (T10) to the third lumbar vertebra (L3) were identified by dissection of three cadavers. ESP injections of dye (0.5 mL kg -1 ) were performed in seven cadavers using as landmarks the T12 transverse process (ESP Tp ) on one side and the lateral aspect of the T12 mammillary process (ESP Mp ) on the opposite side. Additionally, five cadavers were injected with dye (0.5 mL kg -1 ) bilaterally on the lateral aspect of the L2 mammillary process (ESP Mp&#95;L2 ). Nerve staining effect was analyzed after gross anatomic dissections. The number of stained nerves was analyzed using the Mann-Whitney U test., Results: Gross anatomic dissections showed that the medial and lateral branches of the DBSN change their path in relation to the epaxial muscles caudal to T11. Approaches ESP Tp and ESP Mp at T12 stained 2 (0-2) and 3 (2-4) medial (p = 0.01) and 3 (3-4) and 2 (0-2) lateral (p = 0.03) branches, respectively. Injection ESP Mp&#95;L2 stained 3 (2-4) medial and 2 (0-3) lateral branches. Injections ESP Mp and ESP Mp&#95;L2 produced a preferential cranial spread from the injection site. No ventral branches of the spinal nerves were stained with either technique., Conclusions and Clinical Relevance: These results suggest that the mammillary process should be used as anatomic landmark to perform ultrasound-guided ESP blocks in the thoracolumbar spine caudal to T11 when targeting the medial branches of the DBSN. Injections should be performed one spinal segment caudal to the level intended to desensitize., (Copyright © 2022 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the role of Dixon T2-weighted water-fat separation technique in predicting the outcome of lumbar transforaminal epidural injections (TFESIs)., Methods: Patients who underwent TFESI of a single spinal nerve within 3 months after magnetic resonance imaging (MRI) exam between August 2018 and April 2020 were identified. The patients were classified into positive or negative outcome groups based on the response to the TFESI procedure. Two musculoskeletal radiologists measured the signal intensity of the injected side spinal nerves, contralateral side spinal nerves, and subcutaneous fat on axial Dixon T2-weighted water-only images, and the diameter of spinal nerve on axial Dixon T2-weighted in-phase images of the pre-procedural MRI. The measured values of the injected side spinal nerves were compared between the two groups and with the contralateral side spinal nerve., Results: A total of 94 patients were included, 76 in the positive outcome group and 18 in the negative outcome group. The mean signal intensity and the nerve-to-fat signal ratio of the injected side spinal nerve were significantly higher in the positive outcome group than in the negative outcome group (793.78 vs. 679.19, p = 0.016; 4.21 vs. 3.28, p = 0.003). In the positive outcome group, the diameter of the spinal nerve was significantly higher on the injected side than on the contralateral side (6.91 mm vs. 6.37 mm, p = 0.016)., Conclusions: The mean signal intensity and the nerve-to-fat signal ratio of the spinal nerve on axial Dixon T2-weighted water-only images can help predict patient response to the TFESI., Key Points: • Applying the Dixon technique to lumbar spine MRI can help predict patient response to the TFESI procedure. • An increased nerve-to-fat signal ratio and mean spinal nerve signal intensity on axial Dixon T2-weighted water-only images predicted favorable TFESI outcomes., (© 2021. European Society of Radiology.)

Introduction/aims: Ultrasound (US) studies have demonstrated patchy enlargement of spinal and peripheral nerves in Guillain-Barré syndrome (GBS). However, whether ultrasound yields useful information for early classification of GBS has not been established. We aimed to evaluate nerve ultrasound in patients with GBS in northern China and compare the sonographic characteristics between demyelinating and axonal subtypes., Methods: Between November 2018 and October 2019, 38 hospitalized GBS patients within 3 wk of disease onset and 40 healthy controls were enrolled. Ultrasonographic cross-sectional areas (CSA) of the peripheral nerves, vagus nerve, and cervical nerve roots were prospectively recorded in GBS subtypes and controls., Results: Ultrasonographic CSA exhibited significant enlargement in most patients' nerves compared with healthy controls, most prominent in cervical nerves. The CSA tended to be larger in acute inflammatory demyelinating polyneuropathy (AIDP) than in acute motor axonal neuropathy (AMAN)/acute motor and sensory axonal neuropathy (AMSAN), especially in cervical nerves (C5: 5.9 ± 1.6 mm 2 vs. 7.0 ± 1.7 mm 2 , p = .042; C6: 10.5 ± 1.8 mm 2 vs. 12.0 ± 2.1 mm 2 , p = .033). The chi-squared test revealed significant differences in nerve enlargement in C5 (p < .001), C6 (p < .001), the proximal median nerve (p < .001), and the vagus nerve (p = .003) between GBS and controls. The vagus nerve was larger in patients with autonomic dysfunction than in patients without it (2.3 ± 1.0 mm 2 vs. 1.4 ± 0.5 mm 2 , p = .003)., Discussion: The demyelinating subtype presented with more significant cervical nerve enlargement in GBS. Vagus nerve enlargement may be a useful marker for autonomic dysfunction., (© 2021 Wiley Periodicals LLC.)

Objectives: With the development of percutaneously inserted devices, peripheral nerve stimulation (PNS) has been gaining attention within chronic pain literature as a less invasive neurostimulation alternative to spinal column and dorsal root ganglion stimulation. A majority of current PNS literature focuses on targeting individual distal nerves to treat individual peripheral mononeuropathies, limiting its applications. This article discusses our experience treating dermatomal pain with neurostimulation without needing to access the epidural space by targeting the proximal spinal nerve with peripheral nerve stimulation under ultrasound-guidance., Materials and Methods: A temporary, percutaneous PNS was used to target the proximal spinal nerve in 11 patients to treat various dermatomal pain syndromes in patients seen in an outpatient chronic pain clinic. Four patients received stimulation targeting the lumbar spinal nerves and seven patient received stimulation targeting the cervical or thoracic spinal nerves., Results: The case series presents 11 cases of PNS of the proximal spinal nerve. Seven patients, including a majority of the patients with lumbar radiculopathy, had analgesia during PNS. Four patients, all of whom targeted the cervical or thoracic spinal nerves, did not receive analgesia from PNS., Conclusion: PNS of the proximal spinal nerve may be an effective modality to treat dermatomal pain in patients who are not candidates for other therapies that require access to the epidural space. This technique was used to successfully treat lumbar radiculopathy, post-herpetic neuralgia, and complex regional pain syndrome., (© 2020 International Neuromodulation Society.)

A 43 year-old male presented with a relapsing and progressive systemic inflammatory disorder with central nervous system (CNS) involvement. After a two years follow up, he was diagnosed with hemophagocytic lymphohistiocytosis (HLH), based on clinical, laboratory and radiological findings. Treatment was started with anakinra, a recombinant humanised interleukin-1 (IL-1) receptor antagonist. Clinical response was good. Laboratory and radiological findings showed no disease activity throughout a five years follow-up period. Several immunosuppressive agents have been used in HLH without any good outcomes. This is the first case report of HLH with CNS involvement responsive to chronic treatment with anakinra., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: To evaluate the accuracy of ultrasonographic guidance for injection near the ventral rami of the cervical spinal nerves (VRCSN)., Study Design: Ex vivo study., Sample Population: Ten cadavers (n = 40 injections)., Methods: Left and right VRCSN at C4/5 and C5/6 were infiltrated at the intervertebral foramen (IVF) under ultrasonographic guidance. A vertically orientated 3.5-MHz curvilinear probe was used to identify the craniocaudal midpoint of the articular process joint (APJ). The probe was moved ventrally until the IVF was identified. An 18-gauge 15-cm-long spinal needle was aimed immediately below the ventral margin of the cranial articular process, where 1 mL of latex was injected. Cadavers were dissected, and the location of the latex was recorded relative to the ventral ramus, the spinal cord, and the vertebral artery., Results: Direct infiltration of the ventral ramus occurred in 73% (29/40) of injections; 15% (6/40) of injections were < 0.5 cm from the ventral ramus, and 13% (5/40) of injections were > 0.5 cm (maximum 1.5 cm). Latex was located at a mean of 2.4 cm (range, 0.8-4) from the spinal cord and 0.9 cm (range, 0-1.5) from the vertebral artery., Conclusion: Ultrasonographic guidance of perineural injections of the caudal VRCSN was repeatable and accurate, with 88% of injections located within 0.5 cm of the ventral ramus. Iatrogenic damage was limited to one penetration into the vertebral artery., Clinical Significance: Ultrasonographic guidance of perineural injections of the caudal VRCSN may be considered by operators experienced in cervical APJ scanning in horses with suspected cervical spinal nerve compression., (© 2021 The American College of Veterinary Surgeons.)

Background and Objectives: The periarticular sacroiliac joint (SIJ) technique has become an important area of focus, and the quartering of the SIJ posterior ligamentous region has been proposed as a way to refine this technique. However, detailed nerve distribution combined with the division of the SIJ posterior ligamentous region is lacking. We aimed to explore the innervation of the SIJ posteriorly based on the quartering of the SIJ posterior ligamentous region., Methods: Sixteen SIJs from eight embalmed cadavers were studied. Each SIJ posterior ligamentous region was equally divided into areas 0-3 from top to bottom. The origin, distribution, quantity, transverse diameter, spatial orientation, relation with bony structures, and the number of identifiable terminal nerve branches in each area were examined., Results: Areas 0-1 were innervated by the lateral branches of the dorsal rami of L4-L5 directly in all specimens. Areas 2-3 were innervated by that of both lumbar and sacral nerves via the posterior sacral network (PSN), with L5 contributing to the PSN in all specimens and L4 in 68.75%. The number of identifiable terminal nerve branches were significantly higher in areas 2-3 than in areas 0-1., Conclusions: The inferior part of the SIJ posterior ligamentous region seems to be the main source of SIJ-related pain and is innervated by lumbar and sacral nerves via the PSN. However, the superior part directly innervated by lumbar nerves should not be neglected, and further clinical verification is needed., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate the efficacy and safety of ultrasound-guided selective nerve branch blockage in the treatment of lumbar spinal nerve posterior branch syndrome., Methods: A total of 40 patients with lumbar spinal nerve posterior branch syndrome treated by Pain Clinic from May 2017 to December 2018 were selected. According to the method used in locating site for nerve blockage, the patients were divided into ultrasound-guided group and anatomical positioning group, with 20 cases in each group. In anatomical positioning group, there were 7 males and 13 females, aged (63.42±7.71) years old, weighted (63.65±10.72) kg, numerical rating scale (NRS) was (6.61±1.52) scores, course of disease was (16.55±4.68) months. Pain sites:4 cases at L 2,3 , 8 cases at L 3,4 , 11 cases at L 4,5 , and 11 cases at L 5 S 1 . In ultrasound-guided group, there were 10 males and 10 females, aged (59.58±10.21) years old, weighted (60.61±13.81) kg, NRS was(6.84±2.43) scores, and course of disease was(13.70±5.98) months. Pain sites:6 cases at L 2,3 , 6 cases at L 3,4 , 9 cases at L 4,5 , and 13 cases at L 5 S 1 . Ultrasound-guided group used ultrasound-guided selective posteromedial branch and posterolateral branch nerve blockage, and the anatomical positioning group used anatomical localization method to block the posteromedial branch and posterolateral branch of lumbar spinal nerve. Each nerve branch was injected 3 ml of 0.125% ropivacaine. The number of treatment required and prone position time of each treatment were recorded, and the NRS scores of patients at the time points of immediately after the end of the treatment, the first week, the second week, the first month and the third month were evaluated. And adverse events such as local anesthetic allergy and poisoning, local puncture infection, total spinal anesthesia, dizziness, drowsiness, nausea, vomiting and other adverse reactions were observed., Results: There were no statistically significant differences in gender, age, weight, NRS, course of disease and pain segment distribution between two groups ( P >0.05). The number of treatment required in anatomical positioning group was significantly higher than that in ultrasound-guided group ( P <0.000 1). During each treatment, the time in the prone position of the patients in anatomical positioning group was significantly lower than that in ultrasound guided group ( P < 0.000 1). NRS scores immediately after the end of treatment, 1 week, 2 weeks, 1 month and 3 months, anatomical positioning group were 2.98 ±0.25, 3.04 ±0.38, 3.37 ±0.47, 3.42 ±0.85, 3.50 ±0.43, respectively, 2.94 ±0.31, 3.00 ±0.29, 3.21 ±0.68, 3.16 ± 0.94, 3.17±0.53 in ultrasound-guided group, and there was significant difference at 1 month and 3 months between two groups( P < 0.05). There were no adverse events such as local anesthetic allergy and poisoning, local puncture infection, and total spinal anesthesia, and no adverse reactions such as lethargy, nausea, and vomiting occurred in two groups. There were 6 cases of dizziness in anatomical positioning group and 12 cases in ultrasound guided group. The difference between two groups was statistically significant( P <0.05)., Conclusion: Comparedwith anatomicalpositioning, ultrasound-guided selective nerve branch block for the treatment of posterior branch of the lumbar spinal cord syndrome can reduce the number of treatments and maintain a longer therapeutic effect, but it is also necessary to pay attention to the time of each treatment to avoid dizziness and other adverse reactions.

Abstract: MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).The fiber bundles reconstruction was optimized in terms of eliminating the muscle fibers contamination using the segmentation of cauda equina, the effects of the normalized quantitative anisotropy (NQA) and angular threshold on reconstruction of the LSP. In this study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA) and the regions of interest positioning was precisely adjusted bilaterally and symmetrically in each individual subject.The diffusion data were processed in individual L3-S2 nerve fibers using the generalized Q-sampling imaging algorithm. Data (mean FA, mean diffusivity, axial diffusivity and radial diffusivity, and normalized quantitative anisotropy) were statistically analyzed using the linear mixed-effects model. The MR neurography was performed in MedINRIA and post-processed using the maximum intensity projection method to demonstrate LSP tracts in multiple planes.FA values significantly decreased towards the sacral region (P < .001); by contrast, mean diffusivity, axial diffusivity, radial diffusivity and NQA values significantly increased towards the sacral region (P < .001).Fiber tractography of the LSP was feasible in all examined subjects and closely corresponded with the nerves visible in the maximum intensity projection images of MR neurography. Usage of NQA instead of FA in the proposed algorithm enabled better separation of muscle and nerve fibers.The presented algorithm yields a high quality reconstruction of the LSP bundles that may be helpful both in research and clinical practice., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: The purpose of this study was to evaluate the effectiveness of computed tomography (CT)-guided infiltration of greater occipital nerve (GON) for the treatment of refractory craniofacial pain syndromes other than occipital neuralgia., Materials and Methods: Fifty-six patients suffering from refractory craniofacial pain syndromes were included between 2011 and 2017. There were 33 women and 23 men with a mean age of 50.7 years±13.1 (SD) (range: 27-74 years). CT-guided infiltration was performed at the intermediate site of the GON with local anesthetics and cortivazol. Twenty-six (26/56; 46%) patients suffered from chronic migraine, 14 (14/56; 25%) from trigeminal neuralgia and 16 (16/56; 29%) from cluster headaches. Clinical success at 1, 3, and 6 months was defined by a decrease of at least 50% of pain as assessed using visual analog scale (VAS)., Results: Mean overall VAS score before infiltration was 8.7±1.3 (SD) (range: 6 - 10). Mean overall VAS scores after infiltration were 2.3±3 (SD) (range: 0 - 10) (P<0.01) at one month, 3.5±3.3 (SD) (range: 0 - 10) (P<0.01) at three months and 7.6±1.3 (SD) (range: 1-10) (P<0.01) at six months. After infiltration, clinical success was achieved in 44 patients (44/56; 78.5%) at 1 month, 37 patients (37/56; 66%) at 3 months and 13 patients (13/56; 23%) at 6 months. Clinical success according to the clinical presentation were as follows: 88% (23/26) at one month, 73% (19/26) at 3 months, and 23% (6/26) at 6 months in patients with chronic migraine, 81% (13/16), 69% (11/16) and 31% (5/16) in those with cluster headaches and 57% (8/14), 50% (7/14) and 14% (2/14) in those with trigeminal neuralgia. No major complications due to CT-guided GON infiltration were reported in any patient., Conclusion: CT-guided infiltration at the intermediate site of the GON appears as an effective treatment of craniofacial pain syndromes especially in patients with chronic migraine and those with cluster headaches., (Copyright © 2020. Published by Elsevier Masson SAS.)

Background: Fluoroscopy-guided blockade of the greater occipital nerve (GON) is an accepted method for treating the symptoms of cervicogenic headaches (CGHs). However, the spread patterns among different injectate volumes of fluoroscopy-guided GON blocks are not well defined., Objective: A cadaveric study was established to determine the spread patterns of different volumes of dye injectate within a fluoroscopic GON block. Study Design . Cadaveric study. Setting . Xingtai Institute of Orthopaedics; Orthopaedic Hospital of Xingtai., Methods: 15 formalin-fixed cadavers with intact cervical spines were randomized in a 1 : 1 : 1 ratio to receive a fluoroscopy-guided GON injection of a 2, 3.5, or 5 ml volume of methylene blue. The suboccipital regions were dissected to investigate nerve involvement., Results: The suboccipital triangle regions, including the suboccipital nerves and GONs, were deeply stained in all cadavers. The third occipital nerve (TON) was stained in 7 of 10 administered 2 ml injections and in all the 3.5 ml and 5 ml injections. Compared to the 3 ml injectate group, the 5 mL cohort consistently saw injectate spreading to both superficial and distant muscles. Limitations . Given that cadavers were used in this study, cadaveric soft tissue composition and architecture can potentially become distorted and consequently affect injectate diffusion., Conclusions: A 3.5 or 5 mL fluoroscopy-guided GON injection of methylene blue successfully stains the GON, TON, and suboccipital nerves. This suggests that such an injection would generate blockade of all three nerve groups, which may contribute to the efficacy of the block for CGH. A volume of 3.5 ml may be enough for the performance of a fluoroscopy-guided GON block for therapeutic purposes., Competing Interests: All the authors declare that they have no conflicts of interest., (Copyright © 2020 Zhanfeng Song et al.)

Objective: Peripheral nerve stimulation provides targeted stimulation and pain relief within a specific nerve distribution. This technical case report provides a method to perform selective nerve root stimulation of thoracic and lumbar spinal nerves using ultrasonography., Methods: Ultrasound-guided peripheral nerve stimulation of thoracic and lumbar spinal nerves allows better visualization of soft tissue anatomy and planning of needle trajectory., Conclusions: Ultrasound-guided peripheral nerve stimulation procedures may provide a safer method for neurostimulation lead placement when compared with fluoroscopic-guided techniques., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Diffusion tensor imaging (DTI) is useful to evaluate lumbar nerves visually and quantitatively. Multi-band sensitivity encoding (MB-SENSE) is a technique to reduce the scan time. This study aimed to investigate if super-multi-gradient DTI with multi-band sensitivity encoding (MB-SENSE) is better in evaluating lumbar nerves than the conventional method., Methods: The participants were 12 healthy volunteers (mean age 33.6 years). In all subjects, DTI was performed using echo planar imaging with different motion probing gradient (MPG) directions (15 without MB, and 15, 32, 64, and 128 with MB) and the lumbar nerve roots were visualized with tractography. In the five groups, we evaluated the resultant DTI both visually and quantitatively. For visual measures, we counted the number of fluffs and disruptions of the nerve fibers. For quantitative measures, the fractional anisotropy (FA) and standard deviation of the fractional anisotropy (FA-SD) values at two regions (proximal and distal) of the lumbar nerve roots were quantified and compared., Results: Among the five groups, the number of fluffs decreased as the number of MPG directions increased. However, the number of disruptions showed no significant differences. The FA-SD values decreased as the number of MPG directions increased, indicating that the signal variation was reduced with multi-gradient directional DTI., Conclusion: High-resolution multi-directional DTI with MB-SENSE may be useful to visualize nerve entrapments and may allow for more accurate DTI parameter quantification with opportunities for clinical diagnostic applications.

The outcomes from spinal nerve decompression surgery are highly variable with a sizable proportion of elderly foraminal stenosis patients not regaining good pain relief. A better understanding of nerve root compression before and following decompression surgery and whether these changes are mirrored by improvements in symptoms may help to improve clinical decision-making processes. This case study used a combination of diffusion tensor imaging (DTI), clinical questionnaires and motor neurophysiology assessments before and up to 3 months following spinal decompression surgery. In this case report, a 70-year-old women with compression of the left L5 spinal nerve root in the L5-S1 exit foramina was recruited to the study. At 3 months following surgery, DTI revealed marked improvements in left L5 microstructural integrity to a similar level to that seen in the intact right L5 nerve root. This was accompanied by a gradual improvement in pain-related symptoms, mood and disability score by 3 months. Using this novel multimodal approach, it may be possible to track concurrent improvements in pain-related symptoms, function and microstructural integrity of compressed nerves in elderly foraminal stenosis patients undergoing decompression surgery., Competing Interests: Declaration of competing interest None., (Copyright © 2020. Published by Elsevier Inc.)

Objective: We examined selected peripheral and spinal nerves of children aged between two and seven years., Method: High resolution ultrasound was performed in 116 children (2-7 years of age) at 19 predefined landmarks of median, ulnar, tibial, fibular, sural and radial nerves, the vagus as well as cervical spinal nerve 5 and 6. Further, side-to-side measuring and grey-scale analysis was done at selected nerve sites., Results: Nerves of children were on average smaller than those of adults. Nerve growth correlates significantly with age in all nerves, the mean values were similar in the age of two to four years and five to seven years. Body mass index (BMI) and gender showed moderate effect at some nerve sites, however not uniformly in all. A side-to-side difference of up to 30% in median, and up to 20% in tibial nerve can occur in healthy individuals. Grey-scale analysis for echointensity has been performed in median, ulnar and tibial nerves., Conclusion: Nerve size increases with age, BMI and gender have moderate effect. A side-to-side-difference of up to 30% can exist., Significance: Reference values of nerve cross-sectional area, side-to-side-difference and echo intensity are necessary to detect nerve pathology in children as well as in adults., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: To describe a quadratus lumborum (QL) block technique in canine cadavers and the spread of injectate., Study Design: Prospective, randomized, descriptive, experimental anatomic study., Animals: A group of 12 adult canine cadavers., Methods: Gross and ultrasound anatomy of the sublumbar musculature and the relationship with the spinal nerves was studied in two cadavers. Bilateral ultrasound-guided injections were performed in eight cadavers in the fascial plane between the QL and psoas muscle using a dye-lidocaine solution [low volume (LV) 0.15 mL kg -1 or high volume (HV) 0.3 mL kg -1 ]. The ultrasound transducer was positioned caudal and parallel to the proximal aspect of the last rib, and an insulated needle was introduced in-plane using a ventrolateral to dorsomedial approach. Dissections were performed to determine the number of spinal nerves successfully stained (>1 cm) and the presence of injectate in the epidural space or abdominal cavity. Additionally, two cadavers were transversally cryosectioned after QL injection., Results: Ventral branches of the last thoracic and first three lumbar spinal nerves ran between the bundles of the QL muscle and between the QL and psoas muscles. The target fascial plane was ultrasonographically identified and filled with the dye solution following all injections. Ventral branches of the thirteenth thoracic and first, second and third lumbar nerves were stained by 0.0%, 71.4%, 100%, 100%, and 25%, 100%, 100%, 100% using LV and HV, respectively. Multisegmental spread stained the lumbar sympathetic trunk on 0 (0-3) and 3 (0-4) vertebral levels with LV and HV, respectively. No abdominal or epidural spread was identified., Conclusion and Clinical Relevance: Although no significant differences were found, HV resulted in a higher percentage of stain on spinal nerves and sympathetic trunk than LV. Further studies are warranted to determine if the QL block provides somatic and visceral abdominal analgesia in dogs., (Copyright © 2019 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Background: Although the value of ultrasound-guided (USG) lumbar medial branch blocks (MBB) has previously been examined in several clinical trials, blocking the L5 dorsal ramus (DR) remains a technical challenge and we sought to examine the accuracy of a novel technique targeting this level., Methods: In this prospective cohort study, 115 patients scheduled for an L4 MBB and L5 DR block underwent an ultrasound scan to assess their lower spine sonoanatomy. Subjects in whom the necessary landmarks could be visualized underwent a USG L5 DR block using a pivot technique, which involved redirecting a needle from its position on the L5 transverse process after an L4 MBB. Success was determined by a blinded observer who examined the contrast distribution on postprocedural X-ray images. In addition to the final needle position, performance time, the number of needle passes, and any complication were recorded., Results: A total of 100 patients had a USG block and 15 patients (13%) were excluded because of poor landmark visibility. The latter group presented a significantly higher body mass index (38.90±7.50 vs 26.31±4.25 kg/m 2 , p=0.004). A total of five failures were noted (95% success rate), this included three patients with transitional anatomy in whom needles were placed at the wrong level and two cases of incomplete contrast coverage possibly related to the partial intravascular injection. Performance time was 153.93±41.56 s and the median number of needle passes was 2 (range 4). No significant complications were noted., Conclusion: The pivot technique provides a reliable approach for USG L5 DR ramus blocks., Trial Registration Number: NCT03805906., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate the distribution and nerve staining of two volumes of lidocaine-dye solution after ultrasound-guided erector spinae plane (ESP) injections in canine cadavers., Study Design: Experimental cadaveric study., Animals: A total of nine canine cadavers., Methods: ESP injections were performed between the longissimus thoracis muscle and the dorsolateral edge of the ninth thoracic transverse process. Two cadavers were transversally cryosectioned after unilateral ESP injections [0.6 mL kg -1 ; high volume (HV)]. In seven cadavers, bilateral ESP injections with HV or low volume (0.3 mL kg -1 ; LV) were performed. Gadodiamide was added to the injectate for two cadavers and magnetic resonance imaging (MRI) was performed pre- and post-injection. Injectate distribution and nerve staining of the branches of the spinal nerves were recorded after gross anatomical dissection. The thoracic paravertebral and epidural spaces were examined for dye solution., Results: Cryosections, MRI and gross dissections showed that the injectate spread dorsally to the transverse processes, over the ventromedial aspect of the longissimus thoracis muscle where the medial and lateral branches of the dorsal branches of the spinal nerves are located. LV and HV stained a median (range) of 4 (2-7) and 4 (3-8) medial branches, respectively (p = 0.52). LV and HV stained 4 (2-5) and 5 (4-7) lateral branches (p = 0.26), respectively. Ventral branches were not stained, and dye was not identified in the epidural or paravertebral spaces., Conclusions: and clinical relevance Medial and lateral branches were consistently stained over several spinal segments. The number of nerves stained was not different with HV or LV, and the ventral branches of the spinal nerves were not stained in any cadaver. ESP block may find a clinical application to desensitize structures innervated by the medial and lateral branches of the dorsal branches of the thoracic spinal nerves., (Copyright © 2019 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Degenerative disc disease is a leading cause of chronic back pain in the aging population in the world. Sinuvertebral nerve and basivertebral nerve are postulated to be associated with the pain pathway as a result of neurotization. Our goal is to perform a prospective study using radiofrequency ablation on sinuvertebral nerve and basivertebral nerve; evaluating its short and long term effect on pain score, disability score and patients' outcome. A review in literature is done on the pathoanatomy, pathophysiology and pain generation pathway in degenerative disc disease and chronic back pain. 30 patients with 38 levels of intervertebral disc presented with discogenic back pain with bulging degenerative intervertebral disc or spinal stenosis underwent Uniportal Full Endoscopic Radiofrequency Ablation application through either Transforaminal or Interlaminar Endoscopic Approaches. Their preoperative characteristics are recorded and prospective data was collected for Visualized Analogue Scale, Oswestry Disability Index and MacNab Criteria for pain were evaluated. There was statistically significant Visual Analogue Scale improvement from preoperative state at post-operative 1wk, 6 months and final follow up were 4.4 ± 1.0, 5.5 ± 1.2 and 5.7 ± 1.3, respectively, p < 0.0001. Oswestery Disability Index improvement from preoperative state at 1week, 6 months and final follow up were 45.8 ± 8.7, 50.4 ± 8.2 and 52.7 ± 10.3, p < 0.0001. MacNab criteria showed excellent outcomes in 17 cases, good outcomes in 11 cases and fair outcomes in 2 cases Sinuvertebral Nerve and Basivertebral Nerve Radiofrequency Ablation is effective in improving the patients' pain, disability status and patient outcome in our study.

Background: The aim of this study was to further characterize the clinical phenotype of hepatitis E virus (HEV)-associated neuralgic amyotrophy (NA)., Methods: Three patients with HEV-associated NA underwent clinical, electrodiagnostic, and ultrasound assessment., Results: In all patients, symptoms developed in several phases within a time span of 4-6 weeks, with three or more nerves involved. Symptoms were bilateral in two. In two patients, nerves of the trunk and the lower limb were affected as well. In one patient, three bouts occurred, each heralded by an increase in pain. In the other two, pain subsided quickly and nerve damage developed in two phases. Segmental enlargement with or without hourglass-like constrictions of the nerves was demonstrated by ultrasound in all., Conclusions: The multiphasic presentation, together with the extensive multi-nerve involvement, may reflect a severe and protracted inflammation of the nerves in HEV-associated NA., (© 2019 The Authors. Muscle & Nerve published by Wiley Periodicals, Inc.)

Background: The objective of the study was to determine the reference values for cross-sectional area (CSA) of the nerves in healthy subjects between the age of 2 and 30 years., Methods: High-resolution ultrasonography (HRU) of the median, ulnar, tibial, sural, peroneal and spinal nerves C5-C7 was performed in 72 healthy subjects., Results: The CSA of peripheral nerves demonstrated an age-dependent increase in size at all measurement sites in children up to around 14 years of age. This was most pronounced for large lower limb nerves and least for small nerves. Intra-nerve and inter-nerve variability of nerve CSA did not change with age., Conclusions: This study provides normative values for HRU of peripheral nerves in children and young adults. Adult reference values should not be used for children under the age of 14 years., (© 2019 Wiley Periodicals, Inc.)

Introduction: Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis. The clinical spectrum of ECD is diverse, varying from asymptomatic focal lesion to life-threatening multisystem infiltration. Neurological manifestations of ECD are common, mostly due to the involvement of the central nerve system. However, spinal nerve or peripheral nerve involvement has rarely been mentioned., Case Presentation: Herein, we present a case of a 32-year-old female patient complaining about radiating pain on the front and lateral side of her left thigh for 2 months. Spinal MRI with contrast enhancement showed a space-occupying lesion on the left L3/L4 intervertebral foramen, indicating an initial diagnosis of lumbar nerve schwannoma. The patient underwent surgery to remove the mass and decompress the lumbar nerve. Postoperative histological examination revealed the diffuse infiltration of foamy histiocytes that were CD68 + , CD163 + , and CD1a - on immunostaining, which confirmed the diagnosis of Erdheim-Chester disease. The radiating pain was gradually alleviated and PET-CT was performed but showed no further involvement of ECD., Discussion: To the best of our knowledge, this is the first case of ECD demonstrated as an infiltrative mass on the spinal nerve, with imaging manifestations and compression symptoms similar to those of peripheral nerve schwannoma., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest, (© International Spinal Cord Society 2019.)

The paravertebral spread that occurs after erector spinae plane block may be volume-dependent. This cadaveric study was undertaken to compare the extent of paravertebral spread with erector spinae plane block using different dye volumes. After randomization, twelve erector spinae plane blocks were performed bilaterally with either 10 ml or 30 ml of dye at the level of T5 in seven unembalmed cadavers except for two cases of unexpected pleural puncture using the 10 ml injection. Direct visualization of the paravertebral space by endoscopy was performed immediately after the injections. The back regions were also dissected, and dye spread and nerve involvement were investigated. A total of five 10 ml injections and seven 30 ml injections were completed for both endoscopic and anatomical evaluations. No paravertebral spread was observed by endoscopy after any of the 10-ml injections. Dye spread to spinal nerves at the intervertebral foramen was identified by endoscopy at adjacent levels of T5 (median: three levels) in all 30 ml injections. In contrast, the cases with two, four, and three out of five were stained at only the T4, T5, and T6 levels, respectively, with the 10 ml injection. Upon anatomical dissection, all blocks were consistently associated with posterior and lateral spread to back muscles and fascial layers, especially with the 30 ml injections, which showed greater dye expansion. In one 30 ml injection, sympathetic nerve involvement and epidural spread were observed at the level of the injection site. Although paravertebral spread following erector spinae plane block increased in a volume-dependent manner, this increase was variable and not pronounced. As the injectate volume increased for the erector spinae blocks, the injectate spread to the back muscles and fascial layers seemed to be predominantly increased compared with, the extent of paravertebral spread., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Thoracic erector spinae plane (ESP) block is now used for postoperative analgesia. However, although reports of lumbar ESP have been published, the anesthetic spread and mechanism of action of this technique remains unclear. We describe the lumbar ESP block technique and evaluate the spread of 20ml of solution administered at the level of the transverse process of L4 in a cadaver model., Methods: Observational study after 12 lumbar ESP blocks at L4 on a fresh cadaver model (6 bilaterally). The spread of 20ml of injected contrast solution was assessed by computed tomography in all 6 samples. Four of the samples were evaluated by anatomical study, 2 by plane dissection, and 2 others were frozen and cut into 2-2.5cm axial slices., Results: The injected solution spread from L2 to L5 in a cranio-caudal direction in the erector spinae muscle, reaching the facet joints medially and the thoracolumbar fascia laterally. In 33% of cases the solution did not spread anterior to the transverse process; in 51%, spread was minimal and did not affect the corresponding spinal nerves, and in 2 samples (16%), spread was extensive and reached the corresponding spinal nerves., Conclusions: Lumbar ESP at L4 always acts on the posterior branches of the spinal nerves, but seldom spreads to the paravertebral space to block the spinal nerve., (Copyright © 2019 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.)

Background: Ganglioneuroma is a well-differentiated benign tumor that develops from the ganglion cells of the posterior mediastinum, retroperitoneum, cervical spine, and adrenal glands. The paravertebral body, in which the sympathetic trunk exists, is a common tumor site, and tumor sometimes invades the spinal canal through the intervertebral foramen. There have been no reports regarding tumors with intradural and extradural continuity. We report a paravertebral ganglioneuroma extending between the intradural and extradural spaces and its surgical treatment., Case Description: A 33-year-old man was admitted to the hospital with progressive left lower limb numbness. A dumbbell-type tumor progressing to the spinal canal via the left intervertebral foramen from the paravertebral body at L1-2 was detected, and intradural calcified lesions were found. Pathologic examination of a computed tomography-guided biopsy sample revealed a ganglioglioma. The extradural tumor was removed; however, the left lower limb pain gradually worsened. As complete block was observed on myelography, the intradural tumor was removed 8 months later. Intraoperative findings revealed that the intradural and extradural tumors were continuous through the L1 nerve root., Conclusions: This is the first known reported case of paravertebral ganglioneuroma presenting in continuity between the intradural and extradural spaces., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Intraforaminal ligaments (IFL) in lumbar neural foramina (NF) and their relation to the lumbar spinal nerves (SN) are addressed., Method: Giemsa- and PAS-stained plastinated body slices of 15 lumbar spines were made and compared to MRI and CT data acquired of the same fresh specimens. We dissected one fixed lumbar spine to discuss our results with previous literature. Macroscopic pathophysiological changes and operational interventions at these lumbar spines were excluded., Results: In the NF, thin medial IFL touch the SN. As a second compartment, intermedial vertical IFL are seen. A third lateral horizontal compartment of IFL is formed by thick cranial and caudal ligaments. Ligaments of the second and third compartments have no direct contact with the SN. From medial to lateral, the IFL thicken. All compartments are 3D reconstructed. If compartments of the IFL have no direct contact with the SN seen in the slices, a connection was noticed after dissection., Conclusion: Manual dissection seems to be inappropriate for a detailed study of the IFL. The lateral and intermedial compartments being free of the SN may transmit power and protect the SN, while the thin medial IFL may lead the SN passing the NF under physiological conditions. We conclude from the close topographical relation that the IFL may be relevant in foraminal stenosis. Any herniation in the NF presses IFL to the SN. Therefore, we think the IFL themselves could cause neurogenic claudication in case of their non-physiological turnover. Visualisation of IFL seems to be possible by using MRI. These slides can be retrieved under Electronic Supplementary Material.

Background: Neck pain is one of the most common causes of chronic pain and the fourth leading cause of disability worldwide; it is estimated that between 36% and 67% of this pain is due to facet arthropathy. For patients who have pain refractory to conservative treatments literature supports management with diagnostic cervical medial branch blocks (MBBs) to identify the associated facet innervation as the source of pain followed by therapeutic radiofrequency ablation (RFA) of the identified nerves. Cervical RFA has good published outcomes; however, the procedure is dependent upon the specificity of the diagnostic block to achieve maximal success. Currently, this prerequisite test has false positive rates between 27% and 63% and recent studies have shown that this may, in part, be a consequence of currently accepted injection volumes of 0.50 mL or more, which may decrease the sensitivity of MBBs., Objective: To evaluate the possible differences in volume dispersion between 0.25 and 0.50 mL of injectate during cervical MBBs., Study Design: Cadaveric study., Setting: An academic medical center in the United States., Patients: Not applicable., Methods: This was a cadaveric study in which six subjects were chosen with intact cervical spines. Cervical MBB were performed bilaterally at the midcervical spine, using a posterior approach under fluoroscopic guidance. 0.25 or 0.50 mL of a 9:1 solution of Omnipaque 180 mg iodine/mL and 1% medical grade methylene blue were administered on the left and right sides, respectively. Postinjection computed tomography (CT) imaging and gross dissection were performed to assess injectate spread., Main Outcome Measures: Outcome measures after using commonly injected volumes for cervical MBB, included visualized and measured spread (by CT and gross dissection) of cervical medial branch blocks, coating adjacent structures not targeted by RFA., Results: Postinjection CT imaging and cadaveric dissection demonstrated that, although both volumes adequately coated the medial branches, the 0.50 mL cohort reliably spread dorsally to superficial muscles (splenius) and nerves distant from the targeted nerves (dorsal motor branches to splenius), whereas the 0.25 mL injectate cohort was contained in the deep and intermediate muscular cervical layers directly juxtaposed to the targeted cMBBs., Conclusion: Results suggest that 0.50 mL injections of local anesthetic during cervical MBBs contacts many nonintended targets, thus decreasing the specificity of a targeted diagnostic cervical MBB. Furthermore, we demonstrated that 0.25 mL of injectate reliably bathed the cervical medial branches without extensive extravasation. This indicates that there would potentially be fewer local anesthetic effects on distant tissues, increasing the specificity of cervical MBBs and likely improving RFA planning., (© 2018 American Academy of Physical Medicine and Rehabilitation.)

Objective: The cervicogenic headache is a syndrome caused by dysfunction of the upper cervical spine and its component bony, disc, and/or soft tissue elements. The C2 nerve root may play a pivotal role in cervicogenic headache. In this retrospective study, we evaluated the feasibility and efficacy of ultrasound-guided C2 nerve root coblation in managing 26 patients with cervicogenic headache., Design and Setting: The data were collected retrospectively by reviewing the patient's medical records and pain questionnaires., Subjects and Methods: A total of 109 patients with cervicogenic headache sustained for at least six months were identified. Of those patients, 26 had a visual analog scale score ≥6 and subsequently underwent an ultrasound-guided C2 nerve root coblation., Results: All 26 patients had >50% pain relief one day after coblation. Twenty-three of the 26 patients (92.31%) had a decrease in their pain score of 50% or more at 24-week follow-up. The mean pain score was 7.38 ± 1.13 before coblation and 1.85 ± 0.83 one day after coblation (Bonferroni-adjusted P < 0.001). At 12 and 24 weeks after coblation, the mean pain scores were 2.96 ± 0.96 (P < 0.001) and 3.08 ± 1.38 (P < 0.008), respectively., Conclusions: C2 nerve coblation may provide the majority of patients with a pain relief period as long as 24 weeks. And ultrasound guidance is an efficient method with which to perform coblation., (© 2018 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background and Objectives: Two ultrasound (US)-guided techniques for greater occipital nerve (GON) block have been described for the management of headache disorders: a "proximal or central" technique targeting the GON at the level of the second cervical vertebra and a "distal or peripheral" technique targeting the GON at the level of the superior nuchal line. In this multicenter, prospective, randomized control trial, we compared accuracy, effectiveness, and safety of these two techniques in patients with chronic migraines (CMs)., Methods: Forty patients with refractory CMs were randomized to receive either a proximal or distal US-guided GON block with bupivacaine and methylprednisolone acetate. The primary outcome was the difference in Numerical Rating Score (NRS) for headache intensity at 1 month. Secondary outcomes were effectiveness, performance, and safety-related. Effectiveness-related outcomes included NRS for headache intensity, number of headache days per week, patient satisfaction, quality of life, assessment of sleep quality, and sleep interruption. Performance-related outcomes included procedure time, accuracy of block, and patient discomfort. Safety-related outcomes included an assessment for adverse effects., Results: NRS pain scores were significantly reduced at 24 hours and at 1 week postprocedure in both cohorts and at 1 and 3 months in the proximal group as compared with the baseline. There was no significant difference in NRS pain scores between the two cohorts at any of the follow-up time points. There was a significant reduction in number of headache days per week at 1 month in both groups, and a significant improvement in sleep interruption at 1 week in both groups. There were no significant adverse effects., Conclusions: This study was designed to compare two different US-guided approaches for blocking the GON. Our results demonstrate that both distal and proximal techniques can provide a short-term improvement in headache intensity, reduction in number of headache days per week, and an improvement in sleep interruption. The proximal GON technique may confer more sustained analgesic benefit compared with the distal approach in patients with CM headaches., Trial Registration Number: NCT02031822., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Tangier disease (TD) is an autosomal recessive disorder characterized by severe reduction in high-density lipoprotein and accumulation of cholesterol esters in peripheral nerves and other tissues. The aim of this study was to evaluate whether nerve high-resolution ultrasonography (HRUS) can detect morphological nerve changes in TD., Methods: Three related patients of a previously reported Italian family with Tangier disease, carrying the Y1698X mutation in ABCA1, underwent clinical, neurophysiological, and quantitative nerve HRUS evaluation. Nerve HRUS data were compared with normal controls., Results: Despite neurophysiological abnormalities, no quantitative HRUS abnormality was detected in peripheral nerves., Discussion: Normalcy of HRUS in neurophysiologically abnormal nerves suggests possible subtle abnormalities that escape quantitative HRUS detection. Systematic studies in larger TD cohorts with different mutations are needed to confirm our findings. Muscle Nerve 59:587-587, 2019., (© 2019 Wiley Periodicals, Inc.)

Background: The analgesic benefits of programmed intermittent bolus infusion for thoracic paravertebral block remain unknown., Objective: The aim of this study was to compare the analgesia from intermittent bolus infusion with that of a continuous infusion after thoracic paravertebral block., Design: A randomised controlled study., Setting: A single centre between December 2016 and November 2017. Seventy patients scheduled for video-assisted thoracoscopic surgery were included in the study., Intervention(s): Patients were randomly assigned to receive 0.2% levobupivacaine via continuous infusion (5 ml h, continuous group) or programmed intermittent bolus infusion (15 ml every 3 h, bolus group) after an initial 15-ml bolus injection of 0.2% levobupivacaine., Main Outcome Measures: The main outcome was the amount of rescue fentanyl (per kg of body weight) consumed within 24 h after surgery. Secondary outcomes were postoperative pain scores, plasma levobupivacaine concentrations and the number of dermatomes anaesthetised., Results: There was no significant difference between the continuous and bolus groups in the postoperative consumption of fentanyl (median [interquartile range] 5.5 [4 to 9.5] μg kg versus 6 [3.5 to 9] μg kg respectively, P = 0.45) and postoperative pain scores within 24 h. At 20 h after initiating the infusions, there was no statistically significant difference between the two groups in terms of the plasma levobupivacaine concentration. The number of dermatomes anaesthetised to pinprick and cold testing was significantly greater in the bolus group., Conclusion: Our findings suggest that postoperative pain and opioid usage are similar with either programmed intermittent bolus infusion or continuous infusion after thoracic paravertebral block. Programmed intermittent bolus infusion provides a wider sensory blockade and could benefit patients requiring a wider extent of anaesthesia., Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR; URL: http://umin.ac.jp/ctr/, ID: UMIN000023378).

Neuropathic pain remains underrecognised and ineffectively treated in chronic pain sufferers. Consequently, their quality of life is considerably reduced, and substantial healthcare costs are incurred. The anatomical location of pain must be identified for definitive diagnosis, but current neuropsychological tools cannot do so. Matrix metalloproteinases (MMP) are thought to maintain peripheral neuroinflammation, and MMP-12 is elevated particularly in such pathological conditions. Magnetic resonance imaging (MRI) of the peripheral nervous system has made headway, owing to its high-contrast resolution and multiplanar features. We sought to improve MRI specificity of neural lesions, by constructing an MMP-12-targeted magnetic iron oxide nanoparticle (IONP). Its in vivo efficiency was evaluated in a rodent model of neuropathic pain, where the left lumbar 5 (L5) spinal nerve was tightly ligated. Spinal nerve ligation (SNL) successfully induced mechanical allodynia, and thermal hyperalgesia, in the left hind paw throughout the study duration. These neuropathy characteristics were absent in animals that underwent sham surgery. MMP-12 upregulation with concomitant macrophage infiltration, demyelination, and elastin fibre loss was observed at the site of ligation. This was not observed in spinal nerves contralateral and ipsilateral to the ligated spinal nerve or uninjured left L5 spinal nerves. The synthesised MMP-12-targeted magnetic IONP was stable and nontoxic in vitro . It was administered onto the left L5 spinal nerve by intrathecal injection, and decreased magnetic resonance (MR) signal was observed at the site of ligation. Histology analysis confirmed the presence of iron in ligated spinal nerves, whereas iron was not detected in uninjured left L5 spinal nerves. Therefore, MMP-12 is a potential biomarker of neuropathic pain. Its detection in vivo , using IONP-enhanced MRI, may be further developed as a tool for neuropathic pain diagnosis and management.

Background: Sacral fracture and sacral nerve injury remain problems in orthopedics, especially in a sacral fracture combined with an anterior sacral nerve injury. Treating a sacral nerve injury with open reduction neurolysis or more conservative treatment cannot meet the clinical needs. Open reduction sacral nerve neurolysis will increase the number of severe, life-threatening injuries, regardless of whether the anterior or posterior approach is used. In recent years, computer- and robot-assisted orthopedic surgery has emerged as part of many clinical treatments., Methods: For an unstable pelvic fracture with an anterior sacral nerve injury, we established a comprehensive and integrated solution. To achieve closed reduction, minimally invasive fixation, and minimally invasive anterior sacral nerve neurolysis, the Starr Frame, navigation robot, and Da Vinci robot were jointly applied., Results: The Starr Frame is very helpful for closed reduction percutaneous fixation in complex pelvic fractures. In this study, a minimally invasive fixation technique for the navigation robot in the pelvic fracture was explored. Although the patient had delayed anterior sacral nerve compression pain after surgery, we developed an approach and surgical method using the Da Vinci robot to explore the sacral nerve by celiac decompression. The patient was relieved of nerve pressure and pain., Conclusions: This treatment method could be an alternative treatment for pelvic fractures and sacral nerve injury. The application of this treatment is a safe and feasible option that can be employed to manage early and late nerve repair with sacral fractures when open surgery or conservative treatment is unsuitable.

Aim: To seek the efficacy of selective spinal nerve blocks in the treatment of groin pain that are irresponsive to peripheral nerve blocks., Material and Methods: This retrospective study comprised 17 patients with ilioinguinal, iliohypogastric, and genitofemoral neuralgias treated between 2017 and 2018., Results: All patients received diagnostic peripheral nerve blocks and/or TAP blocks with blind or ultrasound-guided techniques. Four patients had ineffectual peripheral nerve blocks, after which they underwent T12 and L1 selective spinal nerve blocks. All four patients had satisfactory results., Conclusion: If distal peripheral nerve blocks are ineffective, an upper level nerve lesion, a lesion in the lumbar plexus or an L1 radiculopathy should be considered in ilioinguinal, iliohypogastric, and genitofemoral neuralgias. Upper level nerve blocks should be performed before deciding on surgery.

Introduction: This study explored potential diagnostic markers of nerve ultrasound in differentiating amyotrophic lateral sclerosis (ALS) from mimic disorders., Methods: Ultrasound of the median, ulnar, and tibial nerves was conducted in 53 patients with ALS, 32 patients with ALS-mimic disorders, and 30 controls. Nerve cross-sectional area (CSA) and distal-proximal ratios were calculated., Results: The median nerve CSA in the upper arm was decreased (7.9 ± 1.3 mm 2 vs. 9.0 ± 1.4 mm 2 , P < 0.05), and the median nerve wrist-upper arm ratio was increased in ALS patients compared with controls (1.3 ± 0.4 vs. 1.1 ± 0.2; P < 0.01). In differentiating ALS from mimic presentations, assessment of median nerve CSA in the upper arm and comparison of a median and ulnar nerve CSA distal-proximal ratio provide diagnostic potential., Discussion: Assessment of nerve CSA combined with calculation of nerve CSA distal-proximal ratio provides a useful marker to aid in the diagnosis of ALS. Muscle Nerve 58:777-783, 2018., (© 2018 Wiley Periodicals, Inc.)

Background: Diffusion tensor imaging (DTI) has been applied in the lumbar and sacral nerves in vivo, but information about the reproducibility of this method is needed before DTI can be used reliably in clinical practice across centers., Purpose: In this multicenter study the reproducibility of DTI of the lumbosacral nerves in healthy volunteers was investigated., Study Type: Prospective control series., Subjects: Twenty healthy subjects., Field Strength/sequence: 3T MRI. 3D turbo spin echo, and 3.0 mm isotropic DTI scan., Assessment: The DTI scan was performed three times (twice in the same session, intrascan reproducibility, and once after an hour, interscan reproducibility). At site 2, 1 week later, the protocol was repeated (interweek reproducibility). Fiber tractography (FT) of the lumbar and sacral nerves (L3-S2) was performed to obtain values for fractional anisotropy, mean, axial, and radial diffusivity., Statistical Tests: Reproducibility was determined using the intraclass correlation coefficient (ICC), and power calculations were performed., Results: FT was successful and reproducible in all datasets. ICCs for all diffusion parameters were high for intrascan (ranging from 0.70-0.85), intermediate for interscan (ranging from 0.61-0.73), and interweek reliability (ranging from 0.58-0.62). There were small but significant differences between the interweek diffusivity values (P < 0.0005). Depending on the effect size, nerve location, and parameter of interest, power calculations showed that sample sizes between 10 and 232 subjects are needed for cross-sectional studies., Data Conclusion: We found that DTI and FT of the lumbosacral nerves have intermediate to high reproducibility within and between scans. Based on these results, 10-58 subjects are needed to find a 10% change in parameters in cross-sectional studies of the lumbar and sacral nerves. The small significant differences of the interweek comparison suggest that results from longitudinal studies need to be interpreted carefully, since small differences may also be caused by factors other than disease progression or therapeutic effects., Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:951-963., (© 2018 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.)

Objective: To observe outcomes of anterior controllable antedisplacement fusion (ACAF) in treatment of degenerative kyphosis with stenosis (DKS) and analyze probability of C5 nerve palsy., Methods: From 2016 to 2017, a consecutive cohort of adults with DKS underwent ACAF. All patients underwent cervical radiography, computed tomography, and magnetic resonance imaging. Operative duration, blood loss, and hospital stay were estimated. Radiologic assessment included kyphotic correction, decompression width, and spinal canal area. Postoperative curvature of spinal cord was observed on sagittal magnetic resonance imaging. Japanese Orthopaedic Association score was used to evaluate neurologic status. C5 nerve palsy and other complications were recorded., Results: The study included 49 patients. There was significant kyphosis correction postoperatively (-19.4° vs. 3.5°, P < 0.01). On cross-sectional computed tomography, mean decompression width was 19.0 mm, and spinal canal area was 218.5 mm 2 . On sagittal magnetic resonance imaging, spinal cord curvature was classified into 5 types: type I, lordosis; type II, straight with no shifting; type III, straight with shifting; type IV, sigmoid; and type V, kyphosis. After ACAF, the spinal cord was maintained in good curvature with no shifting in all patients. No patient presented with C5 nerve palsy. Mean postoperative Japanese Orthopaedic Association score was significantly better than preoperatively (14.9 points vs. 9.0 points, P < 0.01), with mean improvement rate of 79.8%., Conclusions: ACAF provides in situ decompression and good curvature to the spinal cord. Good neurologic recovery is obtained with lower incidence of C5 nerve palsy when ACAF is used to treat DKS., (Copyright © 2018 Elsevier Inc. All rights reserved.)