Peripheral Nerve Pathology Research Articles

Role of Ultrasonography in the Evaluation of Peripheral Nerve Pathologies: A Study of 200 Cases.

The aim of this study is to ascertain the role of ultrasonography in appraising the structural intricacies of peripheral nerve pathologies. (1) To scrutinize the anatomy of both normal and abnormal peripheral nerves. (2) Assess different parameters like continuity of the nerve, echotexture, vascularity, cross-sectional area, and thickness of the nerve in various pathologies. In a prospective observational study conducted at the Department of Radio Diagnosis, Tertiary Care Centre, the study design focused on the examination of 200 cases utilizing a high-resolution 9-14 Mhz and 17 Mhz linear array transducer, integrated into the Aplio 400 Canon Ultrasound System. Among the total cases, 62 were identified as traumatic neuropathy cases, 52 as entrapment neuropathy cases, 14 as infective neuropathy cases, 54 as thermal neuropathy cases, 14 as metabolic neuropathy cases, and 4 as nerve-tumor cases. In conclusion, this investigation illuminates the dynamic role of ultrasonography as an invaluable diagnostic instrument in appraising peripheral nerve pathologies. The noninvasive attributes, widespread availability, and economic viability of ultrasonography render it a pragmatic choice for clinicians. This inquiry buttresses the escalating significance of ultrasonography within neurology, emphasizing its potential to revolutionize the terrain of peripheral nerve pathology assessment.

Migraine/Headache "Tender Spots" Represent Referred Pain From Nerve Compression/Neuromas and Are Not "Trigger Points".

To minimize confusion in description of the clinical examination of the patient with migraine/headaches and implement peripheral nerve concepts into the surgical approach to treating the patient with migraines, the historical origin of the phrase "trigger point" is explored. The symptoms of migraine/headache are due to stimulation of the cranial/peripheral nerve being interpreted as due to stimulation of the meningeal innervation. Use of the phrase "extraction of trigger points" is discouraged in favor of either neurolysis of a compressed nerve or resection of a neuroma, depending upon the peripheral nerve pathology.

A systematic review of steroid use in peripheral nerve pathologies and treatment.

The use of corticosteroids has become a part of the standard of care in various pathologies but their use in peripheral nerve injury treatment is limited. Given corticosteroids' anti-inflammatory properties and their regulatory role in neuronal protein production and myelination, corticosteroids could serve as an adjunct therapy for peripheral nerve injuries. This review aims to systematically investigate the current use of corticosteroid treatment in peripheral nerve pathologies. The systematic search was performed on PubMed, MEDLINE, EMBASE, Scopus, Cochrane, and Web of Science using keywords such as "corticosteroid treatment," "peripheral nerve damage," "peripheral neuropathy," and "complications." The PRISMA guidelines were used to conduct the systematic review and all articles were reviewed by the corresponding author. After the initial search, individual study titles and abstracts were further screened and categorized using an inclusion and exclusion criteria followed by a final full-text review. Out of the total 27,922 identified records, 203 studies were included based on the selection criteria. These studies focused on the use and efficacy of steroids across a spectrum of compression and non-compression peripheral neuropathies such as cubital tunnel syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Various studies noted the promising role of steroids in offering pain relief, nerve block, and nerve regeneration effects. Additionally, safety considerations and potential complications regarding steroid use in peripheral nerve injuries were analyzed. While there is currently limited clinical utilization of corticosteroids in peripheral nerve pathologies, the anti-inflammatory and regenerative effects that steroids provide may be a beneficial tool in managing various peripheral neuropathies and their associated pain. Additional clinical trials and investigation into the mechanism of action could improve the reputation of steroid use as peripheral nerve injury treatment.

The peripheral nerve: A neglected topic in Charcot’s neurological work

ABSTRACT Jean-Martin Charcot (1825–1893) did not show much interest in the peripheral nervous system and its associated pathologies. He found it difficult to place the peripheral nerve within his classification of disorders; it appeared to be an exception to his theories. Even the pathology that he described in 1886 with Pierre Marie (1853–1940), at the same time as Henry Tooth (1856–1925), and which is now known as Charcot-Marie-Tooth neuropathy, was considered by Charcot to be a potential myelopathy. Charcot, like other physicians, paid little heed to the observations made by Louis Duménil (1823–1890) to support the existence of primitive damage to the peripheral nerve. Charcot approached peripheral nerve pathologies through two indirect routes: amyotrophies not explained by spinal or muscular damage, and the trophic cutaneous consequences of what he called névrites (neuritis), the lesional site of which remains debated. It is noteworthy that Charcot’s approach to peripheral nervous system disorders differed from that of other neurologists of the same time. Augusta Dejerine-Klumpke (1859–1927) in France was more precise than Charcot in her anatomical and clinical descriptions, and Hugo von Ziemssen (1829–1902) in Germany made effective use of electrodiagnostics. Charcot supported the electrical work of Guillaume Duchenne de Boulogne (1806-1875), whom he sometimes presented as one of his mentors. The German physician Wilhelm Erb (1840–1921) developed electrodiagnosis by galvanic and faradic currents. Charcot never made use of Erb’s electrological advancements. With his electrophysiologist Romain Vigouroux (1831–1911), Charcot used medical electricity only for electrotherapy in hysteria.

Neuropathological features of pediatric laryngomalacia

ObjectiveLaryngomalacia is the most common pediatric laryngeal anomaly. The pathophysiology of laryngomalacia is not well defined; the leading hypothesis suggests weak laryngeal tone and neuromuscular discoordination. Only a few studies explored the histopathology of the laryngeal submucosal nerves, with reported nerve hypertrophy. Our study aims to describe the histopathology of submucosal nerves in specimens obtained from children with severe laryngomalacia compared to pediatric cadaveric controls. Study designProspective study. SettingsTertiary care children's hospital. MethodsHistologic and immunohistochemical sections of supraglottic tissue from 26 children with severe laryngomalacia and six pediatric autopsies were digitally scanned and assessed with image analysis software (QuPath), resulting in the identification and measurement of 4561 peripheral nerves and over 100,000 foci of neurofilaments. ResultsChronic inflammation was noted in all patients. Eosinophils were rare. The mean nerve area and perimeter were significantly smaller for patients with laryngomalacia compared to the control group (1594.0 ± 593.2 μm^2 vs. 2612.1 ± 2824.0 μm^2, p < 0.0001, and 158.8 ± 30.3 μm vs. 217.6 ± 165.0 μm, p < 0.0001). Nerve-per-area unit was significantly greater for patients with laryngomalacia compared to controls (1.39E-05 vs. 6.19 E−06, p = 0.009). The mean area and the number of neurofilaments per total nerve area were similar. Immunohistochemistry for calretinin, a marker for intestinal ganglion cells in Hirschsprung disease, was absent from all specimens. ConclusionsThis series includes a comparison of all identifiable nerve fibers obtained from children with severe laryngomalacia and shows that the mucosal nerves are smaller on average than controls. These findings fail to provide support for significant morphologic peripheral nerve pathology in laryngomalacia.

Baxter’s Nerve Entrapment: The Missing Nerve

Baxter’s neuropathy is a rare condition that has often been overlooked in the realm of peripheral nerve disorders. This brief communication aims to shed light on the elusive nature of Baxter’s neuropathy, emphasizing the significance of recognizing and understanding this condition for proper diagnosis and management. By addressing this “missing nerve,” we hope to contribute to improved patient outcomes and enhance the overall understanding of peripheral nerve pathologies.

Adult neuromuscular choristoma, a rare peripheral nerve pathology: illustrative case.

Neuromuscular choristomas (NMCs) are rare tumors involving aberrant intercalation of muscle fibers into peripheral nerves, most commonly the sciatic nerve. Although benign, these lesions risk developing into NMCs with desmoid-type fibrosis (NMC-DTFs), aggressive lesions potentially requiring amputation. Currently, information on NMCs and the link between NMCs and NMC-DTFs is limited in adults, with the majority of cases reported in children. We present the case of a 66-year-old male with a sciatic NMC alongside a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-based systematic review of similar cases to better characterize this lesion in the adult population. A male presented with 10 years of progressive left lower-extremity weakness and paresthesia, and a mildly enlarged proximal sciatic nerve was discovered on magnetic resonance imaging. He underwent left sciatic fascicular nerve biopsy, with histopathological examination identifying the lesion as an NMC. The literature review revealed that our case, alongside other cases of adults with NMCs, shared characteristics similar to NMCs in the pediatric population. More comprehensive studies of adults with NMCs are needed, as the current literature contains limited information concerning disease course, diagnostic characteristics, and treatment. Furthermore, NMCs in adults should be handled with care because of the increased likelihood of transformation to NMC-DTF after surgical intervention.

Diffusion Tensor Imaging of Peripheral Nerves: Current Status and New Developments.

Diffusion tensor imaging (DTI) is an emerging technique for peripheral nerve imaging that can provide information about the microstructural organization and connectivity of these nerves and complement the information gained from anatomical magnetic resonance imaging (MRI) sequences. With DTI it is possible to reconstruct nerve pathways and visualize the three-dimensional trajectory of nerve fibers, as in nerve tractography. More importantly, DTI allows for quantitative evaluation of peripheral nerves by the calculation of several important parameters that offer insight into the functional status of a nerve. Thus DTI has a high potential to add value to the work-up of peripheral nerve pathologies, although it is more technically demanding. Peripheral nerves pose specific challenges to DTI due to their small diameter and DTI's spatial resolution, contrast, location, and inherent field inhomogeneities when imaging certain anatomical locations. Numerous efforts are underway to resolve these technical challenges and thus enable wider acceptance of DTI in peripheral nerve MRI.

Abstract 110: Autoangiogenesis Secondary to Chronic Cocaine Use Mimicking Moya‐Moya

Introduction We present the case of a young male presenting with syncope who was found to have incidental hypodensities on computed tomography (CT) of his head, with magnetic resonance imaging (MRI) concerning for Moya‐Moya related occlusion of the right internal carotid artery, but with digital subtraction angiography (DSA) showing extensive autoangiogenesis and collateralization from all other intracranial vascular territories, without Moya‐Moya related changes. This presumably developed as reactive changes to severe chronic cocaine use. Methods We present a case from a tertiary care center in the borough of Manhattan, New York City, USA. All information is deidentified and exempt from IRB approval. Results A 36‐year‐old man with history significant for asthma, active smoker status, and active cocaine use, presented for loss of consciousness. The patient reported 3 days of upper respiratory symptoms and decreased oral intake with subsequent loss of consciousness immediately preceded by lightheadedness and nausea, and without any post‐event confusion, lacerations, or incontinence. Neurologic history is significant for right upper extremity weakness from 9/2022‐12/2022 that self‐resolved and was believed to be a peripheral nerve pathology. Admission exam without focal deficits. Admission CT of his head showed multifocal confluent hypodensities in the subcortical right frontal lobe. CT Angiogram of head and neck showed severe narrowing at right Internal Carotid Artery (ICA) terminus and right M1 segment with lenticulostriate arterial collateralization, severe bilateral A1 stenosis with distal Anterior Cerebral Artery (ACA) flow suggestive of chronic collateralization, and significant right Posterior Cerebral Artery (PCA) collateralization. Given concern for Moya‐Moya disease, MRI of the brain was obtained and despite no acute infarct, MRI was significant for multifocal white matter T2/FLAIR hyperintensities with the largest in the right frontal lobe. The patient subsequently underwent digital subtraction angiography (DSA) to assess collaterals and stratify for possible need for future encephaloduroarteriosynangiosis (EDAS). DSA showed significant auto‐angiogenesis between numerous vascular territories, including recruitment of right Posterior Cerebral Artery and External Carotid Artery branches to perfuse the territory of the severe right ICA terminus steno‐occlusive disease. With minimal anterograde flow into the right Anterior Choroidal Artery and none to the right Middle Cerebral Artery (MCA), the characteristic Moya‐Moya appearance was not appreciated on DSA given minimal anigogenesis around the right ICA occlusion site. Rather, distal perfusion of the R ICA territory was dependent on collaterals from the right PCA, right ACA via the Anterior Communicating Artery, angiogenesis between the right Anterior Falcine Artery and R ACA, and angiogenesis between the right MCA and ACA/MCA cortical branches. These proliferative changes involved all cranial vascular territories, including those without steno‐occlusive disease. Conclusion Acute cocaine use is associated with increased risk of acute ischemic stroke[1], due in part to its sympathomimetic effects causing vasospasm and to its arrhythmic properties[2]. Neuroadaptation after chronic cocaine use is less well understood though rat models suggest that as cerebral ischemia develops from chronic cocaine use, the HIF‐VEGF pathway is activated to promote angiogenesis to restore local blood flow[3]. We present this case as evidence of a similar angiogenic physiologic response in humans to minimize the microvascular ischemic injury from chronic cocaine use.

The Effect of Focused Vibration on Tibialis Anterior Function in Normal Subjects

Category: Basic Sciences/Biologics; Other Introduction/Purpose: Foot drop is a debilitating condition which may be caused by peripheral nerve pathology. Focused vibration therapy (FVT) is a novel treatment in this setting which aims to improve the response of muscle motor units to nervous stimuli, improving muscle function and rehabilitation potential. This study investigates the effect of FVT on tibialis anterior (TA) function in normal subjects to determine the optimal timing of application. Methods: Fifteen normal subjects with mean age 25.47±3.27 years and BMI of 21.93±1.54kg/m2 were recruited. Using surface electromyography (EMG), a rotary potentiometer, video analysis (KINOVEA software), and force gauges, the activity of TA, ankle range of movement (ROM), and force at maximal isometric voluntary contraction (MVC) in dorsiflexion were measured. Baseline TA strength was recorded, and participants then performed a series of dorsiflexion exercises to induce fatigue. Strength measurements were repeated after a 5-minute rest period (control). This process was repeated with FVT applied before exercise (FVBE) and after exercise (during the rest period, FVAE). FVT was delivered over the TA muscle belly at 75Hz / 0.4mm amplitude. Data was analysed using ANOVA. Results: There was no significant change in EMG readings or dorsiflexion ROM between baseline, control and FVBE/FVAE measurements. Compared to baseline, MVC increased by 10.87N (6.6%) after FVBE (p=0.034) and 13.87N (8.4%) after FVAE (p=0.034). Compared to control, MVC did not increase significantly with FVBE, but did increase by 7.70N (4.3%) following FVAE (p=0.049). Conclusion: FVT improved the MVC of TA - this was most pronounced when FVT was applied during the recovery phase, after exercise. The lack of EMG / ROM improvement is expected in normal subjects. Our results suggest that FVT is more effective than passive rest and may enhance muscle strength recovery. Further work will investigate the optimal dose of FVT and response in patients with pathology.

Shielding the Nerve: A Systematic Review of Nerve Wrapping to Prevent Adhesions in the Rat Sciatic Nerve Model.

Peripheral nerve pathology is frequently encountered in clinical practice among peripheral nerve and extremity surgeons. One major factor limiting nerve regeneration and possibly leading to revision surgeries is the development of traumatic or postoperative adhesions and scarring around nerves. In experimental models, different materials have been studied to limit scar tissue formation when wrapped around nerves. A systematic review of studies describing nerve-wrapping materials in a non-transectional rat sciatic nerve model was performed following the PRISMA guidelines. Literature describing nerve-wrapping methods for the prevention of peripheral nerve scarring in rat sciatic nerve models was identified using PubMed and Web of Science, scanned for relevance and analyzed. A total of 15 original articles describing 23 different materials or material combinations for nerve wrapping were included. The heterogeneity of the methods used did not allow a meta-analysis, thus, a systematic review was performed. Out of 28 intervention groups, 21 demonstrated a preventive effect on scar tissue formation in at least one qualitative or quantitative assessment method. The analyzed literature describes a variety of materials from different origins to limit peripheral nerve scarring and adhesions. Thus, a scar-preventive effect by wrapping peripheral nerves as adhesion prophylaxis seems likely. However, a quantitative comparison of the studies to identify the optimal material or technique is not possible with the diversity of used models and study designs. Therefore, further research needs to be performed to identify the optimal nerve wraps to be used routinely in clinical practice.

Google Trends Analysis of Peripheral Nerve Disease and Surgery

Despite advances in the surgical management of peripheral nerve pathologies over the past several decades, it is unknown how public awareness of these procedures has changed. We hypothesize that Google searches for peripheral nerve surgery have increased over time. Google Trends was queried for search volumes of a list of 40 keywords related to the following topics in peripheral nerve surgery: spasticity, nerve injury, prosthetics, and nerve pain. Monthly relative search volume over the first 5years of the study period (2010-2014) was compared with that of the last 5years (2018-2022) of the study period. Search volumes for keywords "nerve injury," "nerve laceration," "peripheral nerve injury," "nerve repair," "nerve transfer", "neuroma," "neuroma pain," "nerve pain," "nerve pain surgery," and "neuroma pain surgery" all increased more than 10% points in relative search volume over the study period (P < 0.0001 for each keyword). In contrast, searches for "rhizotomy," "spasticity surgery," "targeted muscle reinnervation," "bionic arm," and "myoelectric prosthesis" either decreased or remained stable. Technical terms such as "selective neurectomy," "hyperselective neurectomy," "regenerative peripheral nerve interface," and "regenerative peripheral nerve interface surgery" did not have adequate search volume to be reported by Google Trends. The increase in Google searches related to nerve injury and pain between 2010 and 2022 may reflect increasing public recognition of these clinical entities and surgical techniques addressing them. Technical terms relating to nerve pain are infrequently searched, surgeons should use plain English terms for online discovery. Interest in spasticity and myoelectric prosthetics remains stable, indicating an opportunity for better public outreach.

7T for clinical imaging of benign peripheral nerve tumors: preliminary results.

MRI has become an essential diagnostic imaging modality for peripheral nerve pathology. Early MR imaging for peripheral nerve depended on inferred nerve involvement by visualizing downstream effects such as denervation muscular atrophy; improvements in MRI technology have made possible direct visualization of the nerves. In this paper, we share our early clinical experience with 7T for benign neurogenic tumors. Patients with benign neurogenic tumors and 7T MRI examinations available were reviewed. Cases of individual benign peripheral nerve tumors were included to demonstrate 7T MRI imaging characteristics. All exams were performed on a 7T MRI MAGNETOM Terra using a 28-channel receive, single-channel transmit knee coil. Five cases of four pathologies were selected from 38 patients to depict characteristic imaging features in different benign nerve tumors and lesions using 7T MRI. The primary advantage of 7T over 3T is an increase in signal-to-noise ratio which allows higher in plane resolution so that the smallest neural structures can be seen and characterized. This improvement in MR imaging provides the opportunity for more accurate diagnosis and surgical planning in selected cases. As this technology continues to evolve for clinical purposes, we anticipate increasing applications and improved patient care using 7T MRI for the diagnosis of peripheral nerve masses.

Nodes of Ranvier in health and disease.

Action potential propagation along myelinated axons depends on the geometry of the myelin unit and the division of the underlying axon to specialized domains. The latter include the nodes of Ranvier (NOR), the paranodal junction (PNJ) flanking the nodes, and the adjacent juxtaparanodal region that is located below the compact myelin of the internode. Each of these domains contains a unique composition of axoglial adhesion molecules (CAMs) and cytoskeletal scaffolding proteins, which together direct the placement of specific ion channels at the nodal and juxtaparanodal axolemma. In the last decade it has become increasingly clear that antibodies to some of these axoglial CAMs cause immune-mediated neuropathies. In the current review we detail the molecular composition of the NOR and adjacent membrane domains, describe the function of different CAM complexes that mediate axon-glia interactions along the myelin unit, and discuss their involvement and the underlying mechanisms taking place in peripheral nerve pathologies. This growing group of pathologies represent a new type of neuropathies termed "nodopathies" or "paranodopathies" that are characterized by unique clinical and molecular features which together reflect the mechanisms underlying the molecular assembly and maintenance of this specialized membrane domain.

Canine models of Charcot-Marie-Tooth: MTMR2, MPZ, and SH3TC2 variants in golden retrievers with congenital hypomyelinating polyneuropathy

Congenital hypomyelinating polyneuropathy (HPN) restricted to the peripheral nervous system was reported in 1989 in two Golden Retriever (GR) littermates. Recently, four additional cases of congenital HPN in young, unrelated GRs were diagnosed via neurological examination, electrodiagnostic evaluation, and peripheral nerve pathology. Whole-genome sequencing was performed on all four GRs, and variants from each dog were compared to variants found across >1,000 other dogs, all presumably unaffected with HPN. Likely causative variants were identified for each HPN-affected GR. Two cases shared a homozygous splice donor site variant in MTMR2, with a stop codon introduced within six codons following the inclusion of the intron. One case had a heterozygous MPZ isoleucine to threonine substitution. The last case had a homozygous SH3TC2 nonsense variant predicted to truncate approximately one-half of the protein. Haplotype analysis using 524 GR established the novelty of the identified variants. Each variant occurs within genes that are associated with the human Charcot-Marie-Tooth (CMT) group of heterogeneous diseases, affecting the peripheral nervous system. Testing a large GR population (n = >200) did not identify any dogs with these variants. Although these variants are rare within the general GR population, breeders should be cautious to avoid propagating these alleles.

Ultrasound Imaging and Guidance for Distal Peripheral Nerve Pathologies at the Wrist/Hand.

Ultrasound has emerged as a highly valuable tool in imaging peripheral nerve lesions in the wrist region, particularly for common pathologies such as carpal tunnel and Guyon's canal syndromes. Extensive research has demonstrated nerve swelling proximal to the entrapment site, an unclear border, and flattening as features of nerve entrapments. However, there is a dearth of information regarding small or terminal nerves in the wrist and hand. This article aims to bridge this knowledge gap by providing a comprehensive overview concerning scanning techniques, pathology, and guided-injection methods for those nerve entrapments. The median nerve (main trunk, palmar cutaneous branch, and recurrent motor branch), ulnar nerve (main trunk, superficial branch, deep branch, palmar ulnar cutaneous branch, and dorsal ulnar cutaneous branch), superficial radial nerve, posterior interosseous nerve, palmar common/proper digital nerves, and dorsal common/proper digital nerves are elaborated in this review. A series of ultrasound images are used to illustrate these techniques in detail. Finally, sonographic findings complement electrodiagnostic studies, providing better insight into understanding the whole clinical scenario, while ultrasound-guided interventions are safe and effective for treating relevant nerve pathologies.

Comparison of Magnetic Resonance Imaging and High-Resolution Ultrasound for the Diagnosis of Pathologies of the Peripheral Nerve.

The study was done to evaluate high-resolution ultrasound with Magnetic Resonance Imaging (MRI) for the diagnosis of peripheral nerve pathologies. Ultrasound examination and MRI were performed for selected cases, and their sensitivity and specificity were compared. Ultrasound was found to detect peripheral pathologies with greater accuracy as compared to MRI. Also, ultrasound was found to have higher sensitivity and specificity than MRI. It was concluded that ultrasound is a better adjunct tool for the diagnosis of peripheral nerve lesions when compared with MRI.

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.

Lower extremity peripheral nerve pathology: Utility of preoperative ultrasound-guided needle localization before operative intervention.

Historically, the use of ultrasound (US) in the management of peripheral nervous system (PNS) pathology has been limited to diagnostic confirmation or guidance for interventional injections. This technical case series will demonstrate the utility and versatility of preoperative US-guided needle localization for the excision of lower extremity neuromas and other pathology of the PNS. Five patients with symptomatic lower extremity PNS tumors were retrospectively reviewed. This case series corroborates the technical nuances of localizing lower extremity neuromas by US-guided needle and wire placement prior to operative excision. This was achieved by a multidisciplinary team that included plastic surgery, neurosurgery, and radiology. Five patients had US-guided needle localization of a lower extremity PNS target prior to operative intervention. Three patients had lower extremity neuromas of varying origins, including the lateral femoral cutaneous nerve (LFCN), saphenous nerve, and sural nerve. The remaining two patients had a sciatic nerve sheath Schwannoma and a femoral nerve glomus tumor. Under sonographic visualization, a needle was advanced to the target perimeter and withdrawn, leaving behind a percutaneous guidewire. This technique simplified the marking of the nerve course prior to dissection and led to efficient intraoperative identification of all five PNS tumors without any complications. Preoperative US-guided needle localization led to safe, accurate, and efficient perioperative and intraoperative identification of neuromas and other PNS tumors of the lower extremity prior to excision. By reducing the challenges of nerve identification in a scarred tissue bed, this multidisciplinary approach may decrease postoperative patient morbidity.

A prospective case-control study of excessive fragmentary myoclonus in the upper and lower extremities: Clinical characteristics and electrophysiological correlates

BackgroundExcessive fragmentary myoclonus (EFM) is an incidental finding in video-polysomnography (VPSG) and listed among “Sleep Related Movement Disorders – Isolated symptoms and normal variants” in the ICSD-3. We aimed to prospectively evaluate EFM in the upper and lower extremities in a large sleep laboratory cohort and to investigate clinical characteristics and peripheral nerve pathology in patients with and without EFM. MethodsTwo-hundred consecutive sleep laboratory patients with EFM according to ICSD-3 criteria were included and matched to 100 patients without EFM for age, sex and presence or absence of sleep-related breathing disorder. Patients additionally underwent peripheral neurophysiological work-up. ResultsIn 31/200 (15.5%) patients EFM was present not only in the lower extremities, but also in the upper extremities. Patients with EFM had less REM sleep (%/SPT; median (IQR); 13.8 (9.1–18.2) vs. 17.1 (10.1–20.5); p = 0.008) and the PLMS-Index was higher in patients with EFM than in those without (16.2 vs. 8.8/h; p = 0.009). Polyneuropathy (PNP) and nerve root lesions L5 and S1 were more frequent in patients with than in those without EFM (31.5% vs. 21% and 5% vs. 0%; p = 0.003). ConclusionsIn this large cohort we systematically investigated upper and lower extremities with surface electromyography during sleep and show that EFM is much more frequent in the lower extremities than in the upper extremities and corroborate the association of EFM with peripheral nerve pathology and PLMS.