Lumbosacral Plexus Research Articles

Peripheral Nerve Pathology in Antibody Positive Paraneoplastic Neurological Syndromes (P11-8.005)

<h3>Objective:</h3> To describe peripheral nerve histopathology in neuropathy patients with paraneoplastic neurological syndromes (PNS) supported by autoantibody testing. <h3>Background:</h3> Rare autopsy cases in PNS suggest an association with shared antigens of misdirected cytotoxic T-cells against cancers and neural tissues. Neuropathy may be the first manifestation but reports of peripheral nerve pathology are limited. We sought to review the pathologic findings within nerve biopsies of patients having neuropathies linked to cancer and high-risk paraneoplastic antibody seropositivity. <h3>Design/Methods:</h3> We retrospectively reviewed the clinical data and nerve biopsy reports of patients presenting with neuropathy and paraneoplastic syndromes reviewing their cancer diagnosis and peripheral onsets. <h3>Results:</h3> Twelve sural nerves and one radial nerve were biopsied from patients with the following antibodies: Amphiphysin (n=6); Antineuronal nuclear antibodies (ANNA)-1 (n=2); ANNA-2 (n=2); Collapsin response mediator protein-5 (CRMP-5) (n=2); and Purkinje cytoplasmic antibody (PCA1) (n=1). Antibody testing occurred typically after biopsy or concurrently, and all patients had subacute onsets. Patients had overlapping involvements: length-dependent neuropathies (n=5), cranial neuropathies (n=1), brachial plexopathy (n=1), multiple mononeuropathies (n=2), and lumbosacral radiculoplexus involvement (n=8). Time to diagnosis was prolonged; commonly after one year. Malignancies were diverse including breast, ovarian, bladder, non-small cell lung cancer, small cell lung cancer, and coexisting colon and breast cancer. Fiber density was reduced in all, with multifocality frequently seen. Perineurial injury was absent, but sub-perineurial edema was common (n=4). Significant inflammation was absent in all but 5 cases, where small to moderate-sized CD45 collections were seen with vessel wall involvement with clinical lumbosacral plexus neuropathy (Amphiphysin (n=2), ANNA-2, and CRMP5) or multiple mononeuropathies (PCA-1). <h3>Conclusions:</h3> The absence of inflammatory infiltrates with reduced fiber density in distal sensory nerve biopsies is common in paraneoplastic neuropathies. A proximal inflammatory process is theorized. Microvessel inflammatory infiltrates with vessel wall involvement also occurs especially among lumbosacral plexopathy phenotypes. <b>Disclosure:</b> Dr. Granger has nothing to disclose. Dr. Rajnauth has nothing to disclose. The institution of Dr. Dubey has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB. The institution of Dr. Dubey has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Astellas. The institution of Dr. Dubey has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Argenx. Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for AGRIMS. Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Advances in Neurology . Dr. Dubey has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Moffit Cancer Center . Dr. Dubey has received research support from Department of Defense . Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. Dr. Dubey has received intellectual property interests from a discovery or technology relating to health care. Dr. Mills has received intellectual property interests from a discovery or technology relating to health care. The institution of Dr. Mauermann has received research support from IONIS. The institution of Dr. Mauermann has received research support from Alnylam. Dr. Mauermann has received publishing royalties from a publication relating to health care. Dr. Berini has nothing to disclose. Dr. Dyck has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Akcea/Ionis. Dr. Klein has a non-compensated relationship as a Klein with Neurology Journal that is relevant to AAN interests or activities.

Minimally invasive management of pathologic fractures of the pelvis and sacrum: Tumor ablation and fracture stabilization.

Pathologic fractures of the pelvis/sacrum due to metastatic bone disease (MBD) cause pain and dysfunction due to mechanical instability of the pelvic ring. This study presents our multi-institutional experience with percutaneous stabilization of pathologic fractures and osteolytic lesions from MBD throughout the pelvic ring. The records of patients undergoing this procedure from 2018 to 2022 were reviewed retrospectively from two institutions. Surgical data and functional outcomes were recorded. Fifty-six patients underwent percutaneous stabilization, with a median operative duration of 119 min (interquartile range [IQR]: 92.8, 167) and median estimated blood loss of 50 mL (IQR: 20, 100). The median length of stay was 3 days (IQR: 1, 6), and 69.6% (n = 39) of patients were discharged home. Early complications included one partial lumbosacral plexus injury, three acute kidney injuries, and one case of intra-articular cement extravasation. Late complications included two infections and one revision stabilization procedure for hardware failure. Mean Eastern Cooperative Oncology Group (ECOG) scores improved from 3.02 (SD 0.8) preoperatively to 1.86 (SD 1.1) postoperatively (p < 0.001). Ambulatory status also improved (p < 0.001). Percutaneous stabilization of pathologic fractures and osteolytic defects of the pelvis and sacrum is a procedure that improves patient function, ambulatory status and is associated with a limited complication profile.

The anatomic study and surgical technique for canal decompression with “pedicle-plasty” strategy in lumbar burst fractures with pedicle rupture

ABSTRACT In the treatment of lumbar burst fractures with nerve injury, fusion is often required to rebuild spinal stability, but it can lead to the loss of motor units and increase the occurrence of adjacent segment diseases. Thus, a novel approach of lumbar canal decompression with “pedicle-plasty” strategy (DDP) was needed in clincal treatment. Firstly, image measurement analysis, the images of 60 patients with lumbar spine CT examinations were selected to measure osteotomy angle (OA), distance from the intersection of osteotomy plane and skin to the posterior midline (DM),transverse length of the osteotomy plane (TLOP), and sagittal diameter of the outer edge of superior articular process (SD). Secondary, cadaver study, distance between the intermuscular space and midline (DMSM), anterior and posterior diameters of the decompression (APDD), and lateral traction distance of the lumbosacral plexus (TDLP) were measured on 10 cadaveric specimens. Finally, procedure of DDP was demonstrated on cadaver specimens. OA ranged from 27.68°+4.59° to 38.34°+5.97°, DM ranged from 43.44+6.29 to 68.33+12.06 mm, TLOP ranged from 16.84+2.19 to 19.64+2.36 mm, and SD ranged from 22.49+1.74 to 25.53+2.21 mm. DMSM ranged from 45.53+5.73 to 65.46+6.43 mm. APDD were between 10.51+3.59 and 12.12+4.54 mm, and TDLP were between 3.28+0.81 and 6.27+0.62 mm.DDP was successfully performed on cadaveric specimens. DDP, as a novel approach of decompression of burst fractures with pedicle rupture, can fully relieve the occupation and at the same time preserve the spinal motor unit because of no resection of intervertebral discs and no destruction of facet joints,and has certain developmental significance.

Diagnostic value of proximal cutaneous nerve biopsy in brachial and lumbosacral plexus pathologies

Brachial and lumbosacral plexopathies can result from numerous non-traumatic etiologies, including those of inflammatory, autoimmune, or neoplastic origin, that often require nerve biopsy for diagnosis. The purpose of this study was to evaluate the diagnostic efficacy of medial antebrachial cutaneous nerve (MABC) and posterior femoral cutaneous nerve (PFCN) nerve biopsies in proximal brachial and lumbosacral plexus pathology. Patients undergoing MABC or PFCN nerve biopsies at a single institution were reviewed. Patient demographics, clinical diagnosis, symptom duration, intraoperative findings, post-operative complications, and pathology results were recorded. Biopsy results were classified as diagnostic, inconclusive, or negative based on the final pathology. Thirty patients undergoing MABC biopsies in the proximal arm or axilla and five patients with PFCN biopsies in the thigh or buttock were included. MABC biopsies were diagnostic in 70% of cases overall and 85% diagnostic in cases where pre-operative MRI also demonstrated abnormalities in the MABC. PFCN biopsies were diagnostic in 60% of cases overall and in 100% of patients with abnormal pre-operative MRIs. There were no biopsy-related post-operative complications in either group. In diagnosing non-traumatic etiologies of brachial and lumbosacral plexopathies, proximal biopsies of the MABC and PFCN provide high diagnostic value with low donor morbidity.

Recent Progress in the Classification and Operation of Sacral Fractures.

Most sacral fractures are caused by high-energy, violent injuries, often accompanied by lumbosacral plexus injuries, which can cause instability of the posterior pelvic ring or lumbosacral junction in severe cases. Currently, the most commonly used clinical classification methods are Denis classification, Tile classification, Isler classification, and Denis II classification. In recent years, lumbosacral vertebral injury classification and injury degree scoring systems have often been applied clinically as the choice of treatment methods. At present, the internal fixation and implantation methods of sacral fracture are developing in the direction of positive, efficient, safe, and minimally invasive. But different fixation methods have their own indications, which should be strictly followed. This article reviews the classification of sacral fractures and the latest progress in surgical treatment.

Multi-echo in steady-state acquisition improves MRI image quality and lumbosacral radiculopathy diagnosis efficacy compared with T2 fast spin-echo sequence.

This study compares the performance of a 4-min multi-echo in steady-state acquisition (MENSA) with a 6-min fast spin echo with variable flip angle (CUBE) protocol for the assessment of lumbosacral plexus nerve root lesions. Seventy-two subjects underwent MENSA and CUBE sequences on a 3.0-T MRI scanner. Two musculoskeletal radiologists independently assessed the images for quality and diagnostic capability. A qualitative assessment scoring system for image quality and quantitative nerve signal-to-noise ratio (SNR) and iliac vein and muscle contrast-to-noise ratios (CNR) was applied. Using surgical reports as the reference, sensitivity, specificity, accuracy, and area under the receiver operating characteristic curves (AUC) were evaluated. Intraclass correlation coefficients (ICC) and weighted kappa were used to calculate reliability. MENSA image quality rating (3.679 ± 0.47) was higher than for CUBE images (3.038 ± 0.68), and MENSA showed higher mean nerve root SNR (36.935 ± 8.33 vs. 27.777 ± 7.41), iliac vein CNR (24.678 ± 6.63 vs. 5.210 ± 3.93), and muscle CNR (19.414 ± 6.07 vs. 13.531 ± 0.65) than CUBE (P < 0.05). Weighted kappa and ICC values indicated good reliability. Sensitivity, specificity, and accuracy of diagnosis based on MENSA images were 96.23%, 89.47%, and 94.44%, respectively, and AUC was 0.929, compared with 92.45%, 84.21%, 90.28%, and 0.883 for CUBE images. The two correlated ROC curves were not significantly different. Weighted kappa values for intraobserver (0.758) and interobserver (0.768-0.818) reliability were substantial to perfect. A time-efficient 4-min MENSA protocol exhibits superior image quality and high vascular contrast with the potential to produce high-resolution lumbosacral nerve root images.

Utility of Sensory Nerve Conduction Study in Radiologically Positive Lumbosacral Plexopathy.

MRI is the most appropriate imaging method for visual evaluation of lumbosacral plexopathy (LSP) and a reference for comparing with nerve conduction study (NCS). Eight patients with clinical, electrophysiological, and lumbosacral plexus MRI findings suggestive of LSP were prospectively recruited. Saphenous nerve abnormalities were present in seven patients (88%), compared to three for the superficial fibular (38%), and three for the sural nerve (38%). MRI showed tumor, hematoma, abscess, contrast enhancement, or hyperintense signals on the T2-weighted sequences. The SN has the highest yield in MRI positive LSP and may be a vital adjunct for electrophysiological evaluation of LSP.

Surgical Management of Lumbosacral Plexus Tumors

Lumbosacral plexus tumors are uncommon, and because of their deep location and proximity to critical nerves subserving lower extremity function, understanding surgical approaches and short-term outcomes is important. In a retrospective case series of lumbosacral plexus tumor surgeries performed from May 2000 to July 2021 by a single neurosurgeon, demographic information, clinical presentation, imaging studies, and operative outcomes were analyzed. A total of 42 patients with mean age of 48.3 years (range, 16-84 years) underwent surgery for a lumbosacral plexus tumor. Patients presented with leg pain (n= 25; 59.5%), followed by back/flank pain (n= 5; 11.9%), abdominal/pelvic pain (n= 5; 11.9%), leg weakness (n= 5; 11.9%), and leg numbness (n= 3; 7.1%). The most common tumor pathology was schwannoma (n= 20; 50.0%) followed by neurofibroma (n= 9; 22.5%). A retroperitoneal approach was used in all cases. Gross total resection was achieved in 23 (54.8%) patients, and only 1 (2.4%) patient exhibited symptomatic tumor recurrence after subtotal resection of a malignant tumor. Mean follow-up was 33.1 months (range, 1-96 months). Postoperatively, patient neurological status remained unchanged or improved (n= 37; 88.1%). Complications were infrequent, with 4 (9.5%) patients experiencing new sensory symptoms and 1 patient (2.4%) experiencing new anticipated motor weakness after en bloc resection of a malignant tumor. Indications for surgery include pain and/or neurological symptoms attributable to the lesion or large size if asymptomatic. Careful study of preoperative imaging is necessary to determine the best approach. Intraoperative nerve stimulation is essential to preserve function and guide extent of resection in benign tumors.

Accuracy of Coronal Magnetic Resonance Imaging Diagnosis of Multi-Segmental Lumbar Disc Herniation: A Single-Center Retrospective Analysis.

BACKGROUND Multi-segment herniation of lumbar intervertebral discs is a complex lumbar spine disease, and it is difficult to identify the responsible segment using only magnetic resonance imaging (MRI). The present study screened 47 patients with multi-segment lumbar disc herniation (MSLDH) to evaluate coronal magnetic resonance imaging (CMRI) of three-dimensional fast-field echo with water-selective excitation to identify the responsible segment of multi-segment lumbar disc herniation (MSLDH) and to assess the accuracy and utility of CMRI. MATERIAL AND METHODS This retrospective study included 44 patients with low back pain or lower-extremity symptoms from January 2019 to December 2021. The imaging (including CMRI) and clinical data of the patients were analyzed by 3 independent, blinded experts. The Kappa statistical method was used to characterize the reader-to-reader reliability to qualitatively evaluate the data. RESULTS CMRI showed high diagnostic performance, with 90.2% sensitivity, 94.9% positive predictive value (PPV), 80% negative predictive value (NPV), and 83.4% accuracy, and there were significant differences in hospital length of stay (P=0.013) and surgical bleeding (P=0.006) (P<0.01) between single-segment and multi-segment patients. CONCLUSIONS CMRI is highly accurate in revealing the shape, signal, and position of the intraspinal and extraspinal lumbosacral plexus, and reducing surgical segments can help improve postoperative outcomes for patients.

Ultrasound-guided anterior iliopsoas muscle space block effectively reduces intraoperative hypotension in elderly adults undergoing hip surgery: A randomised controlled trial.

Hypotension often occurs during hip surgery in elderly adults with conventional posterior lumbosacral plexus block. We conducted a randomised controlled trial to determine if simple iliopsoas space block can lower the incidence of intraoperative hypotension (IOH) and provide sufficient perioperative pain relief during hip fracture surgery in elderly adults. Patients undergoing surgery for elderly hip fracture were randomised to receive either an anterior iliopsoas space block with a lateral femoral cutaneous nerve block or a posterior lumbosacral plexus block. The primary outcome was a composite measure of IOH incidence comprising frequency, absolute and relative hypotension durations. Compared to the posterior group, the iliopsoas space block group had a decreased median frequency of IOH [1.09 (0-2. 14) vs. 3 (1.6-4.8), p = 0.001, respectively] along with lower absolute [5 (0-10) min] and relative [minutes below systolic blood pressure of 100 mmHg in % of total anaesthesia time, 6.67 (0-7.65)] duration of IOH compared to the posterior group [35 (10-45) min, p = 0.008; 37.6 (12.99-66.18), p = 0.004, respectively]. The median pain levels in the post-anaesthesia care unit and median intraoperative sufentanil usage were comparable between the iliopsoas space group [2 (1-3); 8 (6-10) μg] and posterior group [1 (0-3); 5 (5-8) μg]. Thermal imaging revealed that the limb injected with the iliopsoas space block had a higher skin temperature than the unblocked limb in the sacral plexus innervated region. A single iliopsoas space block lowers the IOH incidence and provides comparable perioperative analgesia to conventional lumbosacral plexus block. Trial registration at www.chictr.org.cn (ChiCTR2100051394); registered 22 September 2021.

Lumbosacral plexus block using a combination of ultrasound-guided lateral pre-iliac and parasacral approaches in cats

ObjectiveTo describe an ultrasound-guided lateral pre-iliac (LPI) and parasacral (PS) approach in feline cadavers (phase I) and compare the perioperative analgesic use and complications in cats administered LPI and PS blocks (group PNB) or epidural anesthesia (group EPI) for pelvic limb surgery (phase II). Study designExperimental uncontrolled, anatomic and retrospective cohort study. AnimalsA group of eight feline cadavers and 52 medical records. MethodsBilateral LPI and PS approaches with 0.1 mL kg–1 of dye to stain the femoral and obturator nerves and the lumbosacral trunk, respectively, were performed on each cadaver. Nerve staining effect was evaluated upon dissections (phase I). Perioperative analgesics use, and complication rates were retrospectively compared between groups PNB and EPI (phase II). Continuous data were compared using the Mann–Whitney U test and the prevalence of events with Fisher’s exact test. Differences were considered significant when p < 0.05. ResultsDissections revealed that the LPI approach stained 94% and 75% of the femoral and obturator nerves, respectively. The PS approach stained 100% of the lumbosacral trunks. Cats enrolled in group PNB (n = 23) were administered lower doses of intraoperative opioids than those in group EPI (n = 25) (p = 0.006). Intraoperative rescue analgesia was required in 60% and 17.4% of cats enrolled in groups EPI and PNB, respectively (p = 0.003). Group PNB required more intraoperative anticholinergics than group EPI (p = 0.02). There were no differences in postoperative pain scores, analgesic use and complication rates. Conclusions and clinical relevanceThe ultrasound-guided LPI and PS approach stained the femoral/obturator nerves and the lumbosacral trunk, respectively, in feline cadavers. Furthermore, PNB was associated with lower intraoperative opioid use and similar postoperative pain and analgesic use compared with epidural anesthesia in a cohort of cats undergoing surgery of the pelvic limb.

Occult lipomatosis of the nerve as part of macrodystrophia lipomatosa: illustrative case.

Macrodystrophia lipomatosa (MDL) is characterized by progressive overgrowth affecting soft tissues and bony structures and is part of lipomatous overgrowth syndromes. MDL has been associated with lipomatosis of the nerve (LN), an adipose lesion of nerve that has a pathognomonic magnetic resonance imaging (MRI) appearance as well as a mutation in the PIK3CA gene. The authors present a case of occult LN in the setting of MDL. A 2-year-old boy with progressive soft tissue overgrowth of his proximal right lower extremity was initially diagnosed with neurofibromatosis type 1 (NF1). At our institution, NF1 as well as other overgrowth syndromes including PTEN hamartoma tumor syndrome were excluded. He was diagnosed as having so-called MDL. Upon reinterpretation of the patient's MRI studies, short-segment LN involving the proximal sciatic nerve and part of lumbosacral plexus was identified. He underwent 2 debulking/liposuction procedures for soft tissue overgrowth. Genetic testing of tissue revealed a mutation in PIK3CA. Thorough clinical examination (for signs of overgrowth) as well as an MRI study of the entire neural pathway is a critical part of the diagnostic workup to evaluate for LN. The authors believe that an increasing association of LN, even when occult, will emerge that will explain many cases with marked nerve-territory overgrowth.

Lumbar vertebral pattern variation in the common opossum (Didelphis marsupialis Linnaeus, 1758): implication on lumbar nerve distribution

ABSTRACT The lumbar nerve distribution can differ depending on vertebral count variations among individuals of the same species. The variation in the lumbar vertebra formula and the lumbar nerve distribution in twenty adult common opossums (eight female and twelve males) was studied. Radiographs were taken to confirm vertebral identification and count. Two vertebral patterns were recognized: three specimens presented five lumbar vertebrae (5VP) and seventeen individuals presented six lumbar vertebrae (6VP). All the 6VP specimens had the same innervation pattern; however, the 5PV had three different innervation patterns (5PVa, 5VPB, and 5PVc). 5VPa and 6VP differed only in the origin of the lateral femoral cutaneous nerve (L2-L3 and L3, respectively). The differences among 5PVa, 5PVb, and 5VPc were seen in the iliohypogastric nerve, which was formed by L1 in 5VPa and 5VPb, and T13 in 5VPc. The ilioinguinal nerve was formed by L1-L2 in 5VPa and 5VPb, while it was formed by T13-L1 in 5VPc. The genitofemoral nerve was formed by L2-L3 in 5VPa, L2 in 5VPb, and L1-L2 in 5VPc. The cutaneous femoris lateralis was formed by L2-L3 in 5VPa and 5VPc, while it is formed only by L2 in 5VPb. The femoral and obturator nerves were formed by L3-L4 in 5VPa, and L2-L3 in 5VPb and 5VPc. The lumbosacral trunk originated from L4-L5-S1 in 5VP and L5-L6-S1 in 6VP. The data provided in this study may help understand the relationship between the spine and lumbosacral plexus variations and may find application in veterinary spine surgery.

Plexal intraneural perineurioma: an analysis of the clinicoradiologic presentation of this rare variant.

Intraneural (IN) perineurioma is a rare benign peripheral nerve sheath tumor, typically presenting as a painless, progressive mononeuropathy in adolescents. A rare plexal variant has been described, although there are little data describing its clinicoradiologic features. Herein, we present the largest case series of plexal IN perineuriomas reported in the literature. Electronic medical records (EMR) from 1990 to 2022 from a single academic institution were reviewed for a diagnosis of IN perineurioma involving the brachial or lumbosacral plexus. This identified 18 patients, of which 17 had available MR imaging. We reviewed the EMR for demographics, clinical presentation, imaging characteristics, and surgical outcomes. Eighteen patients were identified. Most patients were male (11/18, 61%) and first developed symptoms at the age of 9.6years (range 7months to 55years). Diagnosis occurred on average at the age of 22years (4-57years), which is significantly earlier than distal IN perineurioma (p = 0.0096). All patients (100%, 17/17) presented with motor polyneuropathy and muscular atrophy in multiple nerve distributions, with associated sensory loss (12/17, 71%). Most plexal lesions occurred in the brachial plexus (66%, 12/18). Five (29%, 5/17) patients presented with a hand/foot discrepancy, and 5 patients (29%) had a limb length discrepancy. Five patients underwent tendon transfer, of which two had failure of tendon transfer at most recent follow-up (50%, 2/4) due to progression of neurologic loss affecting the donors. Of patients managed nonoperatively, 87% of patients (6/7) with follow-up information demonstrated disease progression with worsening motor function or sensory loss, and 2 patients demonstrated progression on imaging at most recent follow-up. Plexal perineurioma represents an uncommon variant of IN perineurioma that presents as a progressive motor and sensory polyneuropathy in childhood or early adolescence. Surgical management remains controversial, and tendon transfer tends to result in poor long-term surgical outcomes.

Multisequence magnetic resonance neurography of brachial and lumbosacral plexus in chronic inflammatory demyelinating polyneuropathy: correlations with electrophysiological parameters and clinical features

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare and challenging demyelinating disorder. It is necessary to increase our understanding of potential connections between imaging, electromyography, and clinical characteristics. The aim of this study was to evaluate the relationships between multisequence magnetic resonance neurography (MRN) findings, electrophysiological parameters, and clinical characteristics in CIDP patients. A cross-sectional study. Overall, 51 CIDP patients underwent MRN of the brachial and lumbosacral plexus, and nerve conduction studies. The inflammatory Rasch-built overall disability scale (I-RODS) questionnaire, CIDP disease activity status (CADS) scale, and muscle strength scores were evaluated by two neurologists. Electrophysiological parameters, clinical information, and multiparameter-MRN were analyzed for correlations. Multiparameter-MRN includes diameter, nerve-to-muscle T2 signal intensity ratio (nT2), contrast-enhanced ratio (CR), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) of bilateral plexus nerve roots. Electrophysiological parameters that were not elicited were significantly higher in the lower extremities than in the upper extremities, and those were higher in sensory nerve conduction than in motor. There were moderate correlations between motor nerve conduction velocity and distal motor latency in nerve diameter, nT2, FA, and ADC, respectively (|r|, 0.45-0.64, p < 0.05). The correlations between CR and sensory nerve conduction velocity and peak latency were moderate, and ADC had a positive correlation with compound motor action potential amplitude (|r|, 0.45-0.63). FA correlated negatively with the course (r = -0.62) and cerebrospinal fluid (CSF) protein (r = -0.41), whereas ADC had correlated positively with CSF protein (r = 0.34). Only CR had a moderately negative correlation with CADS (r's = -0.57). Muscle strength in all extremities was positively correlated with FA (r's range, 0.41-0.49). There was no significant correlation between I-RODS scores and multiparameter-MR. MRN-derived multiparameter [nerve size, nT2, and diffusion tensor imaging (DTI) parameters] could serve as quantitative biomarkers of myelin sheath integrity in CIDP. DTI parameters and CR correlated with clinical characteristics better than morphological parameters-MR for CIDP patients.

An Updated Review of Magnetic Resonance Neurography for Plexus Imaging.

Magnetic resonance neurography (MRN) is increasingly used to visualize peripheral nerves in vivo. However, the implementation and interpretation of MRN in the brachial and lumbosacral plexi are challenging because of the anatomical complexity and technical limitations. The purpose of this article was to review the clinical context of MRN, describe advanced magnetic resonance (MR) techniques for plexus imaging, and list the general categories of utility of MRN with pertinent imaging examples. The selection and optimization of MR sequences are centered on the homogeneous suppression of fat and blood vessels while enhancing the visibility of the plexus and its branches. Standard 2D fast spin-echo sequences are essential to assess morphology and signal intensity of nerves. Moreover, nerve-selective 3D isotropic images allow improved visualization of nerves and multiplanar reconstruction along their course. Diffusion-weighted and diffusion-tensor images offer microscopic and functional insights into peripheral nerves. The interpretation of MRN in the brachial and lumbosacral plexi should be based on a thorough understanding of their anatomy and pathophysiology. Anatomical landmarks assist in identifying brachial and lumbosacral plexus components of interest. Thus, understanding the varying patterns of nerve abnormalities facilitates the interpretation of aberrant findings.

The lumbosacral plexus in two Didelphis species (Didelphidae, Didelphimorphia): origin and nerve distribution.

Morphological studies provide knowledge that allow us to understand how animals interact with the natural environment or the captivity. The goal of this study was to describe the origin and antimeric distribution of lumbosacral plexus nerves in Didelphis aurita and D. albiventris. Fourteen adult cadavers of D. aurita, seven males and seven females, and 13 adult cadavers of D. albiventris, nine males and four females were used. The specimens were sexed, identified, fixed and dissected until the origins of the lumbosacral plexus nerves were exposed. Data were represented as absolute frequency and simple percentage. The lumbosacral plexuses derived a trunk for the femoral and obturator nerves from the ventral branches of L3-L4 (75%) in D. aurita, and in D. albiventris the femoral nerve of L3-L4 (73.1%) and the obturator nerve of L3-L4 (61.5%). In both species, formation of a lumbosacral trunk derived from L5-L6-S1 occurred in 78.6% of D. aurita and 61.5% of D. albiventris. The origin and distribution of lumbosacral plexus nerves of the studied species present similarities with domestic and wild eutherian mammals.

Contralateral Sacral 1 Root Transection and Transfer for Lumbosacral Plexus Avulsion Injuries

Contralateral sacral roots (cS1) transfer to treat avulsion injuries of lumbosacral plexus (LSP) has been described, however; concerns about its safety remain. We performed a systematic review of a hypothesis regarding safety of cS1 transection and transfer for treatment of LSP avulsion injuries from available studies. A literature search on Pub Med, Cochrane database and Goggle scholar was performed using appropriate key words for choosing relevant articles. Two authors independently assessed the methodological quality of selected articles using Brink’s criteria and results were analysed using level of evidence. The literature search retrieved a total of 877 publications; out of which 9 articles met the inclusion criteria and were reviewed. 6 articles were investigated for both the reliability and validity and 3 articles evaluated qualitatively; all were of limited quality. Though all studies showed that cS1 nerve root transfer leads to improvement in motor power of muscles and sensory recovery neurotised by cS1 with transient donor site morbidity however; evidence is limited. cS1 nerve root transection and transfer for the repair of LSP avulsion injury appears to be a safe option but the evidence is limited and further validation of this finding is needed.

ANATOMICAL VARIATIONS OF SCIATIC NERVE - A CADAVERIC STUDY

Introduction: Sciatic nerve arises from lumbosacral plexus. It divides into tibial and common peroneal nerves from pelvis to popliteal region. The sciatic nerve usually exits from gluteal region below the piriformis muscle. Variations in course and level of division of sciatic nerve are well documented in the literature. Aim: The aim of the study is to evaluate for variations in relationship between the piriformis muscle and sciatic nerve and also the variations in the level of division of sciatic nerve. Materials and Methods: This study was done on 80 lower limbs of the 40 embalmed cadavers during routine anatomical dissections in the Department of Anatomy, Siddhartha Medical College, Vijayawada. Regions were dissected according to the guidelines and variations in sciatic nerve course and level of division were noted. Results: In this study we noted that relationships between sciatic nerve and piriformis muscle are of type A in 82.50%, type B in 8.75%, type C in 5.0%, type D in 2.5% and rare type G in 1.25%. With regard to the level of the division of sciatic nerve these are of type I in 28.75%, type II in 8.75%, type III in 6.25%, type IV in 3.75% and type V in 52.5%. Conclusion: The study establishes the variations in sciatic nerve relationship with piriformis muscle and its level of division in south Indian population. These are important to understand the variable symptoms in cases of sciatic nerve injury or compressions, complications during surgeries on gluteal region and also sciatic nerve block anesthesia.

Sacral Multifidus Plane Block – A Way Forward to Provide Perioperative Analgesia for Spinopelvic Fixation Surgery

Sacral Multifidus Plane Block – A Way Forward to Provide Perioperative Analgesia for Spinopelvic Fixation Surgery