Peripheral Nerve Lesions Research Articles

Astrocyte reactivity in the glia limitans superficialis of the rat medial prefrontal cortex following sciatic nerve injury.

The glia limitans superficialis (GLS) on the rodent cortical surface consists of astrocyte bodies intermingled with their cytoplasmic processes. Many studies have observed astrocyte reactivity in the medial prefrontal cortex (mPFC) parenchyma induced by a peripheral nerve injury, while the response of GLS astrocytes is still not fully understood. The aim of our study was to identify the reactivity of rat GLS astrocytes in response to sciatic nerve compression (SNC) over different time periods. The alteration of GLS astrocyte reactivity was monitored using immunofluorescence (IF) intensities of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and NFκBp65. Our results demonstrated that SNC induced GLS astrocyte reactivity seen as increased intensities of GFAP-IF, and longer extensions of cytoplasmic processes into lamina I. First significant increase of GFAP-IF was observed on post-operation day 7 (POD7) after SNC with further increases on POD14 and POD21. In contrast, dynamic alteration of the extension of cytoplasmic processes into lamina I was detected as early as POD1 and continued throughout the monitored survival periods of both sham and SNC operations. The reactivity of GLS astrocytes was not associated with their proliferation. In addition, GLS astrocytes also displayed a significant decrease in GS immunofluorescence (GS-IF) and NFκB immunofluorescence (NFκB-IF) in response to sham and SNC operation compared with naïve control rats. These results suggest that damaged peripheral tissues (following sham operation as well as peripheral nerve lesions) may induce significant changes in GLS astrocyte reactivity. The signaling mechanism from injured peripheral tissue and nerve remains to be elucidated.

Quantification and Proximal-to-Distal Distribution Pattern of Tibial Nerve Lesions in Relapsing-Remitting Multiple Sclerosis

PurposeRecent studies suggest an involvement of the peripheral nervous system (PNS) in multiple sclerosis (MS). Here, we characterize the proximal-to-distal distribution pattern of peripheral nerve lesions in relapsing-remitting MS (RRMS) by quantitative magnetic resonance neurography (MRN).MethodsA total of 35 patients with RRMS were prospectively included and underwent detailed neurologic and electrophysiologic examinations. Additionally, 30 age- and sex-matched healthy controls were recruited. 3T MRN with anatomical coverage from the proximal thigh down to the tibiotalar joint was conducted using dual-echo 2‑dimensional relaxometry sequences with spectral fat saturation. Quantification of PNS involvement was performed by evaluating microstructural (proton spin density (ρ), T2-relaxation time (T2app)), and morphometric (cross-sectional area, CSA) MRN markers in every axial slice.ResultsIn patients with RRMS, tibial nerve lesions at the thigh and the lower leg were characterized by a decrease in T2app and an increase in ρ compared to controls (T2app thigh: p < 0.0001, T2app lower leg: p = 0.0040; ρ thigh: p < 0.0001; ρ lower leg: p = 0.0098). An additional increase in nerve CSA was only detectable at the thigh, while the semi-quantitative marker T2w-signal was not altered in RRMS in both locations. A slight proximal-to-distal gradient was observed for T2app and T2-signal, but not for ρ.ConclusionPNS involvement in RRMS is characterized by a decrease in T2app and an increase in ρ, occurring with proximal predominance at the thigh and the lower leg. Our results indicate microstructural alterations in the extracellular matrix of peripheral nerves in RRMS and may contribute to a better understanding of the pathophysiologic relevance of PNS involvement.

An Epidemiological and Etiological Analysis of 5026 Peripheral Nerve Lesions from a European Level I Trauma Center.

Background: Peripheral nerve lesions are associated with debilitating long-term consequences. Albeit being essential for evidence-based clinical decision making, epidemiological and etiological data are scarce. We therefore aimed to comprehensively analyze epidemiological and etiological factors of peripheral nerve lesions in one of the largest cohorts. Methods: We screened a total of 110,667 patients treated at our level I trauma center between January 2012 and July 2020 for nerve lesions. Subsequently, demographics, etiologies, concomitant injuries, and lesion characteristics were analyzed. Results: A total of 5026 patients, predominantly young males suffering from non-work-related nerve injuries, were treated. Proximal levels of injury were more likely to be accompanied by fractures, whereas more distal injuries with concomitant vessel or tendon injury. Main causes were 54.6% lacerations. Acute traumatic nerve injury was treated within 24 h in 55.9% of cases. Conclusions: Given the young age of affected patients, early diagnosis and treatment in specialized centers may facilitate their early return to work and improve long-term functional outcomes. The data show the importance of a special attention on nerve injuries, which may be masked by large accompanying injuries. New findings on lesion characteristics of selected subgroups and accompanying circumstances can support a change in treatment strategies.

Modern MRI Diagnostics of Upper-Extremity-Related Nerve Injuries-A Prospective Multi-Center Study Protocol for Diagnostics and Follow Up of Peripheral Nerve Injuries.

(1) Background: Peripheral nerve injuries are severe injuries with potentially devastating impairment of extremity function. Correct and early diagnosis as well as regular regeneration observation is of utmost importance for individualized reconstruction and the best possible results. Currently, diagnoses and follow-up examinations are based on clinical examinations supported with electroneurography, which often causes delays in treatment and can result in impaired healing. However, there is currently no diagnostic device that can reliably correlate the anatomic–pathological parameters with the functional–pathological changes initially and during therapy. With new technologies such as MR neurography (MRN), precise visualization of potential nerve damage and visualization of the reinnervation processes is assumed to accelerate clinical decision making and accompaniment of individualized treatment. (2) Methods/Design: This prospective clinical study will examine 60 patients after peripheral nerve lesion aged 18–65 years from trauma timepoint onward. Patients should be observed over a period of 18–24 months with regular clinical examinations, electroneurography, and ultrasound to compare the potential of MRN to current gold-standard diagnostic tools. Furthermore, 20 patients with the same inclusion criteria stated above, with an internal fixation and osteosyntheses of humerus fractures, will be examined to determine the visibility of peripheral nerve structures in close proximity to metal. (3) Discussion: Peripheral nerve injuries are often accompanied with severe, expensive, and long-lasting impairment of extremity function. An early and precise diagnosis of the nerve lesion, as well as the healing course, is crucial to indicate the right therapy as soon as possible to save valuable time for nerve regeneration. Here, new technologies such as MRN aim to visualize nerve injuries on fascicular level, providing not only early diagnosis and therapy decisions, but also providing a precise tool for monitoring of reinnervation processes. As severe injuries of a nerve are often accompanied with bone fractures and internal fixation, we also aim to evaluate the visualization feasibility of nerves in close proximity to metal, and ultimately improve the outcome and extremity function of patients after a peripheral nerve injury.

Natural History of Brachial Plexus, Peripheral Nerve, and Spinal Schwannomas.

Management of sporadic schwannomas is often dictated by a patient's clinical presentation and the tumor's behavior. For patients who are managed nonsurgically, there are little data available about the expected natural history. To evaluate the natural history and growth patterns of extracranial schwannomas including tumors of the distal peripheral nerves, spine, and brachial plexus. A retrospective review was performed to identify patients with nonsyndromic extracranial schwannomas at a single tertiary care institution diagnosed between 2002 and 2019. Patient data and tumor characteristics including volume were recorded. Two hundred twenty-seven patients were identified (mean age 51 years, 42% male, average of 27.8-month follow-up). Tumor location was distal peripheral nerve in 82, brachial plexus in 36, and paraspinal in 109. At the time of diagnosis, peripheral lesions were significantly larger than spinal (59 m 3 vs 13 cm 3 ) and brachial plexus lesions (15 cm 3 ). Distinct growth patterns were seen with both distal peripheral nerve and spinal lesions; 34/82 peripheral nerve lesions had fast growth (β = 0.176%/day), and 48 had slow growth (β = 0.021%/day; P < .01). Spinal schwannomas similarly had 30 fast-growing (β = 0.229%/day), 16 moderate-growing (β = 0.071%/day), and 63 slow-growing (β = 0.022%/day; P = .03) subtypes. The brachial plexus had relatively homogeneous growth patterns (β = 0.065%/day). Females had 2.9 times greater odds of having the fast-growing subtype. Distinct growth patterns were seen in extracranial sporadic schwannomas based on tumor location and patient demographics. Fast (>80% volume change per year) vs slow (5%-10% per year) tumor growth can often be ascertained within 2 follow-up images. Awareness of these patterns might have implications for patient counseling and therapeutic decision-making.

The impact of different exercise protocols on rat soleus muscle reinnervation and recovery following peripheral nerve lesion and regeneration.

Background: Incomplete functional recovery following traumatic peripheral nerve injury is common, mainly because not all axons successfully regenerate and reinnervate target muscles. Exercise can improve functional outcomes increasing the terminal sprouting during the muscle reinnervation. However, exercise is not a panacea per se. Indeed, the type of exercise adopted dramatically impacts the outcomes of rehabilitation therapy. To gain insight into the therapeutic effects of different exercise regimens on reinnervation following traumatic nerve lesion, we evaluated the impact of different clinically transferable exercise protocols (EPs) on metabolic and functional muscle recovery following nerve crush. Methods: The reinnervation of soleus muscle in adult nerve-crushed rats was studied following 6 days of different patterns (continuous or intermittent) and intensities (slow, mid, and fast) of treadmill running EPs. The effects of EPs on muscle fiber multiple innervation, contractile properties, metabolic adaptations, atrophy, and autophagy were assessed using functional and biochemical approaches. Results: Results showed that an intermittent mid-intensity treadmill EP improves soleus muscle reinnervation, whereas a slow continuous running EP worsens the functional outcome. However, the mid-intensity intermittent EP neither enhanced the critical mediators of exercise-induced metabolic adaptations, namely, PGC-1α, nor improved muscle atrophy. Conversely, the autophagy-related marker LC3 increased exclusively in the mid-intensity intermittent EP group. Conclusion: Our results demonstrated that an EP characterized by a mid-intensity intermittent activity enhances the functional muscle recovery upon a nerve crush, thus representing a promising clinically transferable exercise paradigm to improve recovery in humans following peripheral nerve injuries.

Alcoholic neuropathy associated with chronic alcohol intake

Alcoholic neuropathy (AN), a debilitating condition that mainly affects chronic alcohol drinkers, is thought to cause lesions in the peripheral nervous system leading to sensory, autonomic, and motor dysfunctions. Despite many studies, the pathogenesis of these lesions is still not completely understood. We investigated few aspects on the development of alcohol-induced peripheral neuropathy, by assessing sensory, motor and autonomic functions, as well as stereological analysis of axonal fibers and myelin sheath of the sciatic nerve. Twelve male Wistar rats were divided into Control group and Alcohol group that was submitted to Two Bottle-Choice Paradigm of intermittent and voluntary alcohol solution intake (20%; v/v) during eight weeks. At the end of treatment, three different sensorium-motor tests were applied - Tactile Sensitivity, Thermal Sensitivity, and Functional Observational Battery (FOB). Quantitative morphometric analysis of sciatic nerve structures was performed by stereological method. Alcohol concentration in the blood was measured to analyze possible correlation between availability of alcohol in the blood and the magnitude of the peripheral nerve lesion. Our data showed a peripheral effect of chronic alcohol intake associated with hyperalgesia and a process of demyelination with a strong correlation with alcohol consumption. This process was associated with increased tactile sensitivity, with behavioral reflexes such as locomotor hyperactivity, changes in gait and balance, and autonomic reflexes such as piloerection.

Evaluation of muscle atrophy after sciatic nerve defect repair – experimental model

Peripheral nerve injuries are one of the most important causes for disability generating considerable costs around the world. Appropriate assessment of the extent of peripheral nerve lesions and the choice of the right therapeutic protocol remain some of the biggest challenges. Non-invasive neuroimaging approaches are suitable in managing peripheral nerve repairs, providing in the same time accuracy details in structural neural detection, with minimal discomfort at a low cost. Medical imaging technology development has led to progress in examination of peripheral nervous system, using a series of tools and methods, such as: ultrasonography (US), positron emission tomography (PET), magnetic resonance imaging (MRI) and magnetic diffusion tensor imaging (DTI). In this study, we evaluated the regeneration process in Wistar rats after sciatic nerve defects repair with 4 different techniques (i.e. nerve graft, rat aorta used as a nerve conduit, rat aorta filled with platelet rich plasma (PRP) and rat aorta filled with stem cells) by using MRI investigation alongside the clinical evaluation. Our results showed that among the 4 batches, the PRP batch had the best results in muscle atrophy condition (both on MRI scan and on gastrocnemius index); on the second place the stem cell batch, then the nerve graft batch and finally the aortic conduit batch. MRI proved to be a reliable non-invasive monitoring method and showed good result in correlation with the footprint test (sciatic functional index) and the gastrocnemius index

Omics approaches to discover pathophysiological pathways contributing to human pain.

Omics approaches to discover pathophysiological pathways contributing to human pain.

Carpal tunnel syndrome in terms of biomechanics. Literature review

Carpal tunnel syndrome is mononeuropathy (damage to one peripheral nerve) of the median nerve as consequence of its compression by surrounding tissues. Carpal syn-drome is included in the group of tunnel neuropathies, of which more than 30 forms are described in the literature, and accounts for up to 9 % of all lesions of peripheral nerves of various etiologies. The prevalence of carpal tunnel syndrome (CTS) among people is 150–276 people per 100,000 people. About 4–5 % of the working-age population aged 40 to 60 suffer from CTS. The peculiarity of compression neuropathies is that they have a progressive nature of the course, resistance to treatment and a tendency to recurrence. All of the above leads to a violation of household and labor adaptation, which is a seri-ous medical and social problem. For the first time, carpal tunnel syndrome was described by J. Parget in 1854. This paper describes the need for a biomechanical approach to the study of carpal tunnel syndrome.

MP23-11 PERIOPERATIVE COMPLICATIONS AFTER RADICAL CYSTECTOMY FOR BLADDER CANCER: AN INTERNATIONAL MULTICENTER COLLABORATION

MP23-11 PERIOPERATIVE COMPLICATIONS AFTER RADICAL CYSTECTOMY FOR BLADDER CANCER: AN INTERNATIONAL MULTICENTER COLLABORATION

P 71 Optical coherence tomography – a future imaging technique of peripheral nerves?

Object: Owing to their complex topography, their long courses and their small diameters peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include magnetic-resonance imaging (MRI) and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical-coherence tomography (OCT) is the first imaging technique that is able to depict a nerve’s ultrastructure at micrometer resolution. Methods: OCT measurement was performed in 32 patients with different peripheral nerve pathologies, i.e. nerve compression syndromes. The nerves were examined during surgery after exposing. Only the sural nerve was twice examined ex vivo . The OCT systems Thorlabs Callisto and Thorlabs Ganymede were used. For intra-operative use, a hand probe was covered with a sterile foil. Different post-processing imaging techniques were applied and evaluated. Results: The intra-operative use of OCT is easy and intuitive. Image artifacts are mainly caused by motion and the sterile foil. If they are kept at a low level, the hyporeflecting bundles of nerve fascicles and their inner parts can be displayed. In the Haralick evaluation the second angular moment (SAM) is most suitable to depict the connective tissue. Conclusion: OCT is a new imaging technique which has shown to be promising in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable. Currently, the method resembles an optical biopsy and can be a supplement to intra-operative sonography, giving high-resolution insight into a suspect area which has been located by sonography in advance. This could be especially helpful in surgery of peripheral nerve lesions in continuity.

A case of esophageal neuromuscular choristoma

BackgroundNeuromuscular choristoma (NMC) is a rare peripheral nerve lesion that is composed of ectopic mature muscle fibers and nerve fascicles, typically involving major nerve roots or trunks, such as the cranial nerves, brachial plexus, and sciatic nerves. The onset of NMC frequently occurs in the first decade of life. Here, we present the first documented case of a case of esophageal NMC in an adult patient.Case presentationA 46-year-old male patient presented in 2018 with a submucosal tumor of the esophagus. Upon presentation, the tumor was approximately 10 mm in diameter, covered by normal mucosa, and located in the left posterior wall of the esophagus in a position that was 30 cm from the incisor. The tumor was discovered incidentally during gastroscopic examination. In March 2021, endoscopic re-examination revealed no significant changes in the tumor. Endoscopic ultrasound revealed an oval hypoechoic mass with a homogeneous internal echo that originated from the muscularis propria with a maximum cross section of 13 mm × 6 mm. Resection was performed under gastroscopy. The resection specimen was 12 mm × 5 mm in size and was a well-demarcated, elastic, hard, and tough with a gray section. Histologically, the specimen consisted of an abundance of smooth muscle fiber bundles intercalated among nerve fibers, but without malignancy. Immunohistochemical examinations revealed positivity for S-100 protein, caldesmon, NSE and desmin, but negativity for CD117, DOG-1, HMB45, and Melan A. There was also aberrant nuclear localization of beta-catenin. Collectively, these findings led to a diagnosis of esophageal NMC.ConclusionsNMC is extremely rare, especially esophageal NMC, and is very challenging to accurately diagnose prior to resection. It is important that we can differentiate NMC from other types of tumors.

Multifunctional chitin-based hollow nerve conduit for peripheral nerve regeneration and neuroma inhibition

The recoverability for peripheral nerve lesions with a long segment defect is much challenging. Conventional methods for sciatic nerve repair excepted for autografts are bridged with nerve guidance conduit (NGC). Herein, the chitin-based NGC (ChT NGC) is firstly reported by facile dissolution, molding and regeneration process, performed excellent nerve regeneration and neuroma inhibition after deposited with anti-inflammatory polydopamine (ChT-PDA NGC). In 10 mm sciatic nerve defect rat model, the restorative effects of ChT-PDA NGC groups are similar to autografts. That is mainly ascribed to the high activity of Schwann cells and claimed by immunofluorescence staining and Western blot analysis. Interestingly, ChT-PDA NGC presents outstanding neuroma inhibition during the nerve regeneration as for the anti-inflammatory activity of PDA. This work provides a facile and novel approach to prepare hollow chitin hydrogel tube, which presents well nerve regeneration and neuroma inhibition, improving the potential high-value application of chitin in biomedical fields.

Microglia-independent peripheral neuropathic pain in male and female mice.

The dominant view in the field of pain is that peripheral neuropathic pain is driven by microglia in the somatosensory processing region of the spinal dorsal horn. Here, to the contrary, we discovered a form of neuropathic pain that is independent of microglia. Mice in which the nucleus pulposus (NP) of the intervertebral disc was apposed to the sciatic nerve developed a constellation of neuropathic pain behaviours: hypersensitivity to mechanical, cold, and heat stimuli. However, NP application caused no activation of spinal microglia nor was pain hypersensitivity reversed by microglial inhibition. Rather, NP-induced pain hypersensitivity was dependent on cells within the NP which recruited macrophages to the adjacent nerve. Eliminating macrophages systemically or locally prevented NP-induced pain hypersensitivity. Pain hypersensitivity was also prevented by genetically disrupting the neurotrophin brain-derived neurotrophic factor selectively in macrophages. Moreover, the behavioural phenotypes as well as the molecular mechanisms of NP-induced pain hypersensitivity were not different between males and females. Our findings reveal a previously unappreciated mechanism for by which a discrete peripheral nerve lesion may produce pain hypersensitivity, which may help to explain the limited success of microglial inhibitors on neuropathic pain in human clinical trials.

Th1/Th17-mediated Immunity and Protection from Peripheral Neuropathy in Wildtype and IL10-/- BALB/c Mice Infected with a Guillain-Barré Syndrome-associated Campylobacter jejuni Strain.

Campylobacter jejuni is an important cause of bacterial gastroenteritis worldwide and is linked to Guillain-Barré syndrome (GBS), a debilitating postinfectious polyneuropathy. The immunopathogenesis of GBS involves the generation of antibodies that are cross reactive to C. jejuni lipooligosaccharide and structurally similar peripheral nerve gangliosides. Both the C. jejuni infecting strain and host factors contribute to GBS development. GBS pathogenesis is associated with Th2-mediated responses in patients. Moreover, induction of IgG1 antiganglioside antibodies in association with colonic Th2-mediated immune responses has been reported in C. jejuni-infected C57BL/6 IL10-/- mice at 4 to 6 wk after infection. We hypothesized that, due to their Th2 immunologic bias, BALB/c mice would develop autoantibodies and signs of peripheral neuropathy after infection with a GBS patient-derived strain of C. jejuni (strain 260.94). WT and IL10-/- BALB/c mice were orally inoculated with C. jejuni 260.94, phenotyped weekly for neurologic deficits, and euthanized after 5 wk. Immune responses were assessed as C. jejuni-specific and antiganglioside antibodies in plasma and cytokine production and histologic lesions in the proximal colon. Peripheral nerve lesions were assessed in dorsal root ganglia and their afferent nerve fibers by scoring immunohistochemically labeled macrophages through morphometry. C. jejuni 260.94 stably colonized both WT and IL10-/- mice and induced systemic Th1/Th17-mediated immune responses with significant increases in C. jejuni-specific IgG2a, IgG2b, and IgG3 plasma antibodies. However, C. jejuni 260.94 did not induce IgG1 antiganglioside antibodies, colitis, or neurologic deficits or peripheral nerve lesions in WT or IL10-/- mice. Both WT and IL10-/- BALB/c mice showed relative protection from development of Th2-mediated immunity and antiganglioside antibodies as compared with C57BL/6 IL10-/- mice. Therefore, BALB/c mice infected with C. jejuni 260.94 are not an effective disease model but provide the opportunity to study the role of immune mechanisms and host genetic background in the susceptibility to post infectious GBS.

Spatial Distribution and Long-Term Alterations of Peripheral Nerve Lesions in Schwannomatosis.

Purpose To examine the spatial distribution and long-term alterations of peripheral nerve lesions in patients with schwannomatosis by in vivo high-resolution magnetic resonance neurography (MRN). Methods In this prospective study, the lumbosacral plexus as well as the right sciatic, tibial, and peroneal nerves were examined in 15 patients diagnosed with schwannomatosis by a standardized MRN protocol at 3 Tesla. Micro-, intermediate- and macrolesions were assessed according to their number, diameter and spatial distribution. Moreover, in nine patients, peripheral nerve lesions were compared to follow-up examinations after 39 to 71 months. Results In comparison to intermediate and macrolesions, microlesions were the predominant lesion entity at the level of the proximal (p < 0.001), mid- (p < 0.001), and distal thigh (p < 0.01). Compared to the proximal calf level, the lesion number was increased at the proximal (p < 0.05), mid- (p < 0.01), and distal thigh level (p < 0.01), while between the different thigh levels, no differences in lesion numbers were found. In the follow-up examinations, the lesion number was unchanged for micro-, intermediate and macrolesions. The diameter of lesions in the follow-up examination was decreased for microlesions (p < 0.01), not different for intermediate lesions, and increased for macrolesions (p < 0.01). Conclusion Microlesions represent the predominant type of peripheral nerve lesion in schwannomatosis and show a rather consistent distribution pattern in long-term follow-up. In contrast to the accumulation of nerve lesions, primarily in the distal nerve segments in NF2, the lesion numbers in schwannomatosis peak at the mid-thigh level. Towards more distal portions, the lesion number markedly decreases, which is considered as a general feature of other types of small fiber neuropathy.

Quantitative magnetic resonance neurographic characterization of peripheral nerve involvement in manifest and pre-ataxic spinocerebellar ataxia type 3.

Knowledge about the exact underlying pathophysiological changes involved in the genesis and progression of spinocerebellar ataxia type 3 (SCA3) is limited. Lower extremity peripheral nerve lesions in clinically, genetically and electrophysiologically classified ataxic and pre-ataxic SCA3mutation carriers were characterized and quantified by magnetic resonance neurography (MRN). Eighteen SCA3mutation carriers and 20 age-/sex-matched healthy controls were prospectively enrolled. All SCA3mutation carriers underwent detailed neurological and electrophysiological examinations. 3 T MRN covered the lumbosacral plexus and proximal thigh to the tibiotalar joint by using T2-weighted inversion recovery sequences, dual-echo relaxometry sequences with spectral fat saturation, and two gradient-echo sequences with and without an off-resonance saturation rapid frequency pulse. Detailed quantification of nerve lesions by morphometric and microstructural MRN markers, including T2 relaxometry and magnetization transfer contrast imaging, was conducted in all study participants. MRN detected peripheral nerve damage in ataxic and pre-ataxic SCA3. The quantitative markers proton spin density (ρ), T2 relaxation time, magnetization transfer ratio and cross-sectional area were decreased in SCA3, indicating chronic axonopathy. MTR and ρ identified early, subclinical nerve damage in pre-ataxic SCA3 and in SCA3mutation carriers without polyneuropathy and were superior in differentiating between all subgroups. Additionally, microstructural markers correlated well with clinical symptom scores and electrophysiological results. Our data provide a comprehensive characterization of peripheral nerve damage in SCA3 and assist in understanding the mechanisms of the multisystemic disease evolution. Evidence of peripheral nerve involvement prior to the onset of clinically overt ataxia might have important implications for designing early intervention studies.

Experts' Perceived Patient Burden and Outcomes of Knee-ankle-foot-orthoses (Kafos) Vs. Microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot Orthoses (Mp-sscos).

Patients with neuromuscular knee-instability assisted with orthotic devices experience problems including pain, falls, mobility issues and limited engagement in daily activities. The aim of this study was to analyse current real-life burden, needs and orthotic device outcomes in patients in need for advanced orthotic knee-ankle-foot-orthoses (KAFOs). An observer-based semi-structured telephone interview with orthotic care experts in Germany was applied. Interviews were transcribed and content-analysed. Quantitative questions were analysed descriptively. Clinical experts from eight centres which delivered an average of 49.9 KAFOs per year and 13.3 microprocessor-stance-and-swing-phase-controlled-knee-ankle-foot orthoses (MP-SSCOs) since product availability participated. Reported underlying conditions comprised incomplete paraplegia (18%), peripheral nerve lesions (20%), poliomyelitis (41%), post-traumatic lesions (8%) and other disorders (13%). The leading observed patient burdens were "restriction of mobility" (n=6), followed by "emotional strain" (n=5) and "impaired gait pattern" (n=4). Corresponding results for potential patient benefits were seen in "improved quality-of-life" (n=8) as well as "improved gait pattern" (n=8) followed by "high reliability of the orthosis" (n=7). In total, experts reported falls occurring in 71.5% of patients at a combined annual frequency of 7.0 fall events per year when using KAFOs or stance control orthoses (SCOs). In contrast, falls were observed in only 7.2 % of MPSSCO users. Advanced orthotic technology might contribute to better quality of life of patients, improved gait pattern and perceived reliability of orthosis. In terms of safety a substantial decrease in frequency of falls was observed when comparing KAFO and MP-SSCO users.

Ultrasound-Guided Thoracodorsal Nerve Block for Post-Breast Reconstruction Discomfort.

CASE PRESENTATION A 76-yr-old woman with prediabetes and estrogen receptor–positive breast cancer diagnosed 2 yrs ago underwent a bilateral mastectomy and breast reconstruction with tissue expander and latissimus dorsi flap 1 yr ago. After the procedure, the patient developed constant muscle hyperactivity and a tight band-like feeling in the lateral aspect of the reconstructed breast flap. Subsequently, the tissue expanders were removed without a significant improvement of her symptoms. She denied numbness, tingling, lancinating, electricity-like pain, or pins/needles sensation. She tried physical therapy, a transcutaneous electrical nerve stimulation unit, and oral baclofen without significant relief. Ultrasound-guided thoracodorsal nerve block with 1% lidocaine and 0.25% bupivacaine was performed with consideration for the positive motor symptoms and lack of cutaneous sensory symptoms in the distribution of the latissimus dorsi flap, as illustrated in the Figures 1 and 2. The patient reported 100% relief of symptoms for 5 days and approximately 50% relief of symptoms for 2 wks. Repeated ultrasound-guided injection as per the patient’s request reproduced a similar pattern of symptom relief.FIGURE 1: Ultrasonographic images of the thoracodorsal nerve (yellow arrow) and surrounding structures using an 8- to 15-MHz linear array probe.FIGURE 2: Ultrasonographic-guided perineural block of thoracodorsal nerve using in-plane approach.More than 250,000 women were diagnosed with breast cancer in 2017 and more than 100,000 breast reconstruction procedures were performed.1,2 Latissimus dorsi flaps are frequently used as an option for salvage reconstruction given presence of healthy muscle tissue and consistent vascular supply. As high as 10% of patients who have latissimus dorsi flaps complain of persistent postsurgical pain lasting months or years. Complaints after latissimus dorsi–based reconstruction include abnormal muscle movement, breast deformity, significant muscle tone at rest, and pain, as illustrated in this case.1 Regarding peripheral nerve lesions, intercostobrachial cutaneous, intercostal, and long thoracic nerve injuries are well-known contributors to post–breast surgery pain syndrome.3,4 The thoracodorsal nerve is often underrecognized as the culprit for post–breast surgery pain syndrome. Surgical denervation of the thoracodorsal nerve was proposed but remains controversial because of potential detriments to the reconstruction.1 This case highlights the diagnostic and therapeutic role of ultrasound-guided thoracodorsal nerve blocks for the evaluation and management of post–breast surgery pain and discomfort.