Comparison of two methods of greater occipital nerve block in patients with chronic migraine: ultrasound-guided and landmark-based techniques.

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.

Challenges of Imaging the Greater Occipital Nerve Using Magnetic Resonance Imaging.

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.

Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches.

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.

A novel simultaneous three-dimensional volumetric morphological imaging and T2-mapping method, multi-interleaved X-prepared turbo-spin echo with intuitive relaxometry provides more accurate quantification of cervical spinal nerves.

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.

Low CERVICAL-2 plane block, a proposed regional anesthetic technique for acute cholecystitis.

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.

Erector spinae plane block at the thoracolumbar spine: a canine cadaveric study.

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 (ESPTp) on one side and the lateral aspect of the T12 mammillary process (ESPMp) 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 (ESPMp_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 ESPTp and ESPMp 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 ESPMp_L2 stained 3 (2-4) medial and 2 (0-3) lateral branches. Injections ESPMp and ESPMp_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.

Nerve ultrasound evaluation of Guillain-Barré syndrome subtypes in northern China.

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 mm2 vs. 7.0 ± 1.7 mm2 , p = .042; C6: 10.5 ± 1.8 mm2 vs. 12.0 ± 2.1 mm2 , 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 mm2 vs. 1.4 ± 0.5 mm2 , 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.

Spinal nerve signal intensity on Dixon T2-weighted water-only sequence: an important outcome predictor after lumbar transforaminal epidural injection.

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.

Central nervous system involvement in adult-onset relapsing hemophagocytic lymphohistiocytosis responsive to maintenance treatment with anakinra.

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.

[Application of ultrasound-guided selective nerve branch blockage in lumbar spinal nerve posterior branch syndrome].

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 L2,3, 8 cases at L3,4, 11 cases at L4,5, and 11 cases at L5S1. 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 L2,3, 6 cases at L3,4, 9 cases at L4,5, and 13 cases at L5S1. 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.

Ultrasonographic guidance for perineural injections of the cervical spinal nerves in horses.

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.

Magnetic resonance tractography of the lumbosacral plexus: Step-by-step.

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.

Anatomical study of the innervation of different parts of the posterior ligamentous region of the sacroiliac joint.

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.

Ultrasound-Guided Peripheral Nerve Stimulation of Cervical, Thoracic, and Lumbar Spinal Nerves for Dermatomal Pain: A Case Series.

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.

Fluoroscopy-Guided Blockade of the Greater Occipital Nerve in Cadavers: A Comparison of Spread and Nerve Involvement for Different Injectate Volumes.

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.

Analysis of the Causes and Experience in the Diagnosis and Treatment of Intravertebral Mobile Nerve Sheath Tumors-Case Report and Review of the Literature.

BACKGROUND: We sought to analyze the clinical data and imaging features from a rare case presenting an intravertebral mobile nerve sheath tumor of the lumbar spine, review the relevant literature, discuss the imaging features and possible causes of the tumor, and propose preventive measures and solutions. CASE DESCRIPTION: The clinical data and imaging data of a patient with a lumbar spinal canal mobile nerve sheath tumor were retrospectively analyzed in conjunction with the relevant literature. The first preoperative lumbar spine magnetic resonance imaging (MRI) showed the tumor located at level L1-2. Further lumbar spine MRI, which was performed 5 days later, showed the tumor was at level L3-4, with a range of motion of 8 cm. End spinal resection of the tumor was performed under general anesthesia, and a tumor, which was cystic solid, was found to be located at level L3-4. The tumor originated from a distinctly twisted and elongated posterior root of the spinal cord, with complete fusion of the tumor-bearing nerve. Both the tumor and tumor-carrying nerve were removed. Postoperative pathologic examination confirmed that the tumor was a nerve sheath tumor. Lumbar MRI on postoperative day 10 showed complete resection of the tumor in the L3-4 spinal canal. The patient was discharged with normal urination and defecation, normal sensation in both lower extremities, grade 5 muscle strength, normal muscle tone, and normal reflexes in both knee and Achilles tendons. CONCLUSIONS: Intravertebral mobile nerve sheath tumors are rare, and the marked distortion and elongation of the carrier nerve seen on MRI are important imaging features of this disease. The possible causes of tumor movement include tumor texture, location, positional changes, and altered cerebrospinal fluid dynamics. Acute changes in intraabdominal pressure caused by forceful defecation may be a high-risk factor for tumor migration. Multiple preoperative MRIs to localize the tumor are particularly important.

Extraforaminal Thoracic and Lumbar Spinal Nerve Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation.

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.

CT-guided infiltration of greater occipital nerve for refractory craniofacial pain syndromes other than occipital neuralgia.

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.

Longitudinal study on nerve ultrasound and corneal confocal microscopy in NF155 paranodopathy.

We report the case of a 27-year-old patient with subacute anti-neurofascin-155 neuropathy with bifacial palsy, who showed excellent response to rituximab. We provide longitudinal data of established clinical scores, nerve conduction studies, antibody titers, and novel imaging methods (nerve ultrasonography and corneal confocal microscopy). Clinical and electrophysiological improvement followed the reduction of serum antibody titer and correlated with a reduction of corneal inflammatory cellular infiltrates whereas the increase in the cross-sectional area of the peripheral nerves remained 12 months after first manifestation. Our findings suggest that novel techniques provide useful follow-up parameters in paranodopathies.

Does the increased motion probing gradient directional diffusion tensor imaging of lumbar nerves using multi-band SENSE improve the visualization and accuracy of FA values?

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.