Ultrasonographic abnormalities in clinically unaffected nerves of patients with nonvasculitic motor and sensorimotor mononeuropathies.

INTRODUCTION/AIMS: Diagnostic criteria for multifocal motor neuropathy (MMN) and multifocal acquired demyelinating sensorimotor neuropathy (MADSAM) require the involvement of at least two peripheral nerves. However, many patients with very similar features have clinical involvement of only a single peripheral nerve, which may preclude their correct diagnosis and treatment. The present study aimed to present a cohort of such patients and discuss the role of ultrasonography (US) in their diagnosis. METHODS: Patients with nonvasculitic immune-mediated motor mononeuropathies (MM) and sensorimotor mononeuropathies (SMM) were recruited prospectively or identified from the electronic records. They were invited to comprehensive follow-up visits consisting of clinical examination, electrodiagnostic (EDx), and US studies. RESULTS: Twenty-four patients (13 men) were studied (11 with MM). The characteristics of MM and SMM patients were very similar to MMN and MADSAM, respectively. The US, in addition to a long-swollen segment (average length, 20 cm) in the clinically affected nerve, revealed nerve swelling in, on average, six additional sites in clinically unaffected nerves. DISCUSSION: In patients with clinical and EDx involvement of only a single nerve, an US demonstration of multifocal peripheral nerve swelling points to a more widespread, probably dysimmune mechanism. Further studies are needed to evaluate the value of US as a supplementary method for the diagnosis of MADSAM and MMN in patients with clinical involvement of a single nerve.

Development of a major histocompatibility complex class II conditional knockout mouse to study cell-specific and time-dependent adaptive immune responses in peripheral nerves.

INTRODUCTION/AIMS: The precise relationship between molecular mimicry and tissue-specific autoimmunity is unknown. Major histocompatibility complex (MHC) class II antigen presenting cell-CD4+ T-cell receptor complex interactions are necessary for adaptive immunity. This study aimed to determine the role of endoneurial endothelial cell MHC class II in autoimmune polyneuropathy. METHODS: Cryopreserved Guillain-Barré syndrome (GBS) patient sural nerve biopsies and sciatic nerves from the severe murine experimental autoimmune neuritis (sm-EAN) GBS model were studied. Cultured conditional ready MHC Class II antigen A-alpha chain (H2-Aa) embryonic stem cells were used to generate H2-Aaflox/+ C57BL/6 mice. Mice were backcrossed and intercrossed to the SJL background to generate H2-Aaflox/flox SJL mice, bred with hemizygous Tamoxifen-inducible von Willebrand factor Cre recombinase (vWF-iCre/+) SJL mice to generate H2-Aaflox/flox; vWF-iCre/+ mice to study microvascular endothelial cell adaptive immune responses. Sm-EAN was induced in Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+, H2-Aaflox/flox; +/+, H2-Aa+/+; vWF-iCre/+ and untreated H2-Aaflox/flox; vWF-iCre/+ adult female SJL mice. Neurobehavioral, electrophysiological and histopathological assessments were performed at predefined time points. RESULTS: Endoneurial endothelial cell MHC class II expression was observed in normal and inflamed human and mouse peripheral nerves. Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+ mice were resistant to sm-EAN despite extensive MHC class II expression in lymphoid and non-lymphoid tissues. DISCUSSION: A conditional MHC class II knockout mouse to study cell- and time-dependent adaptive immune responses in vivo was developed. Initial studies show microvascular endothelial cell MHC class II expression is necessary for peripheral nerve specific autoimmunity, as advocated by human in vitro adaptive immunity and ex vivo transplant rejection studies.

Radical resection of locally advanced and recurrent colorectal carcinoma involving major nerve resection: a systematic review of surgical, oncological and functional outcomes.

BACKGROUND: The aim of this study was to explore the surgical, oncological and quality of life outcomes in the setting of radical resection of colorectal carcinoma involving major nerve resection. METHODS: A systematic review of the literature was registered with the International Prospective Register for Systematic Reviews (PROSPERO) and performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify papers relating to outcomes in radical resection of colorectal cancer where major nerve resection was undertaken. Papers were identified from OVID Medline, EMBASE Classic and Web of Science encompassing all publications in English from January 2010 to June 2023. A total of 1357 nonduplicate studies were identified and screened for relevance, with six studies included in the final review. RESULTS: A total of 354 major nerve resections were undertaken across the six included studies. Overall postoperative morbidity was reported at rates of up to 82%. Two studies considered nerve-resection-specific oncological outcomes, with complete pathological resection achieved at rates comparable to the wider pelvic exenteration cohort (65-68%) and without any overall survival disadvantage being conveyed by major nerve resection (p = 0.78). Two studies considered functional outcomes and noted a transient decrease in physical quality of life over the first 6 months postoperatively (p = 0.041) with significant loss to follow-up. One study considered postoperative pain in nerve resection and noted no significant increase in patient-reported pain scores associated with nerve resection (p = 0.184-0.618). CONCLUSIONS: Major nerve resections in locally advanced and recurrent colorectal cancer remain understudied but with encouraging initial oncological and functional outcomes. Multicentre collaborative prospective reviews are needed to better elucidate contributors to postoperative morbidity and functional deficits and further establish interventions to ameliorate them.

Peripheral regional anaesthesia and outcomes: a narrative review of the literature from 2013 to 2023.

The use of peripheral regional anaesthesia continues to increase, yet the evidence supporting its use and impact on relevant outcomes often lacks scientific rigour, especially when considering the use of specific blocks for a particular surgical indication. In this narrative review, we consider the relevant literature in a 10-yr period from 2013. We performed a literature search (MEDLINE and EMBASE) for articles reporting randomised controlled trials and other comparative trials of peripheral regional anaesthetic blocks vs systemic analgesia in adult patients undergoing surgery. We evaluated measures of effective treatment and complications. A total of 128 studies met our inclusion criteria. There remains variability in the technical conduct of blocks and the outcomes used to evaluate them. There is a considerable body of evidence to support the use of interscalene blocks for shoulder surgery. Saphenous nerve (motor-sparing) blocks provide satisfactory analgesia after knee surgery and are preferred to femoral nerve blocks which are associated with falls when patients are mobilised early as part of enhanced recovery programmes. There are additional surgical indications where the efficacy of cervical plexus, intercostal nerve, and ilioinguinal/iliohypogastric nerve blocks have been demonstrated. In the past 10 yr, there has been a consolidation of the evidence indicating benefit of peripheral nerve blocks for specific indications. There remains great scope for rigorous, multicentre, randomised controlled trials of many peripheral nerve blocks. These would benefit from an agreed set of patient-centred outcomes.

Peripheral nerve decompression for pain relief in the setting of previous obstetrical brachial plexus injury: a retrospective case series.

PURPOSE: In children with previous obstetrical brachial plexus injury (OBPI), upper extremity pain is present in 45 to 66% of patients. Recent literature reports this as musculoskeletal or neuropathic in nature. The purpose of the study is to demonstrate that peripheral nerve decompression, and neurolysis may be an effective treatment for patients with upper extremity pain in the context of previous OBPI. METHODS: A retrospective chart review was performed on patients undergoing peripheral nerve decompression and neurolysis after OBPI by senior author. The primary outcome assessed was pain, and secondary outcome measure was range of motion of the wrist and elbow. Outcome measures were assessed preoperatively as well as at their subsequent follow-up. RESULTS: Six patients were included, with a mean age of 14 years old at time of decompression. Three patients underwent median nerve, two patients underwent ulnar nerve, and one patient underwent posterior interosseous nerve decompression. There was a substantial improvement in pain post-operatively, demonstrated by reduction or resolution of subjective pain in all patients and resolution of Tinel's sign. There was a modest improvement in range of motion. CONCLUSION: This study demonstrates an improvement in subjective pain and range of motion after decompression and neurolysis in small subset of OBPI patients. It generates the hypothesis that peripheral nerve compression is a source of pain that can be addressed in this population. Future research should focus on confirming this hypothesis and assessing treatment options on a larger scale.

Improved 3D DESS MR neurography of the lumbosacral plexus with deep learning and geometric image combination reconstruction.

OBJECTIVE: To evaluate the impact of deep learning (DL) reconstruction in enhancing image quality and nerve conspicuity in LSP MRN using DESS sequences. Additionally, a geometric image combination (GIC) method to improve DESS signals' combination was proposed. MATERIALS AND METHODS: Adult patients undergoing 3.0 Tesla LSP MRN with DESS were prospectively enrolled. The 3D DESS echoes were separately reconstructed with and without DL and DL-GIC combined reconstructions. In a subset of patients, 3D T2-weighted short tau inversion recovery (STIR-T2w) sequences were also acquired. Three radiologists rated 4 image stacks ('DESS S2', 'DESS S2 DL', 'DESS GIC DL' and 'STIR-T2w DL') for bulk motion, vascular suppression, nerve fascicular architecture, and overall nerve conspicuity. Relative SNR, nerve-to-muscle, -fat, and -vessel contrast ratios were measured. Statistical analysis included ANOVA and Wilcoxon signed-rank tests. p < 0.05 was considered statistically significant. RESULTS: Forty patients (22 females; mean age = 48.6 ± 18.5 years) were enrolled. Quantitatively, 'DESS GIC DL' demonstrated superior relative SNR (p < 0.001), while 'DESS S2 DL' exhibited superior nerve-to-background contrast ratio (p value range: 0.002 to < 0.001). Qualitatively, DESS provided superior vascular suppression and depiction of sciatic nerve fascicular architecture but more bulk motion as compared to 'STIR-T2w DL'. 'DESS GIC DL' demonstrated better nerve visualization for several smaller, distal nerve segments than 'DESS S2 DL' and 'STIR-T2w DL'. CONCLUSION: Application of a DL reconstruction with geometric image combination in DESS MRN improves nerve conspicuity of the LSP, especially for its smaller branch nerves.

Optimized 3D brachial plexus MR neurography using deep learning reconstruction.

OBJECTIVE: To evaluate whether 'fast,' unilateral, brachial plexus, 3D magnetic resonance neurography (MRN) acquisitions with deep learning reconstruction (DLR) provide similar image quality to longer, 'standard' scans without DLR. MATERIALS AND METHODS: An IRB-approved prospective cohort of 30 subjects (13F; mean age = 50.3 ± 17.8y) underwent clinical brachial plexus 3.0 T MRN with 3D oblique-coronal STIR-T2-weighted-FSE. 'Standard' and 'fast' scans (time reduction = 23-48%, mean = 33%) were reconstructed without and with DLR. Evaluation of signal-to-noise ratio (SNR) and edge sharpness was performed for 4 image stacks: 'standard non-DLR,' 'standard DLR,' 'fast non-DLR,' and 'fast DLR.' Three raters qualitatively evaluated 'standard non-DLR' and 'fast DLR' for i) bulk motion (4-point scale), ii) nerve conspicuity of proximal and distal suprascapular and axillary nerves (5-point scale), and iii) nerve signal intensity, size, architecture, and presence of a mass (binary). ANOVA or Wilcoxon signed rank test compared differences. Gwet's agreement coefficient (AC2) assessed inter-rater agreement. RESULTS: Quantitative SNR and edge sharpness were superior for DLR versus non-DLR (SNR by + 4.57 to + 6.56 [p < 0.001] for 'standard' and + 4.26 to + 4.37 [p < 0.001] for 'fast;' sharpness by + 0.23 to + 0.52/pixel for 'standard' [p < 0.018] and + 0.21 to + 0.25/pixel for 'fast' [p < 0.003]) and similar between 'standard non-DLR' and 'fast DLR' (SNR: p = 0.436-1, sharpness: p = 0.067-1). Qualitatively, 'standard non-DLR' and 'fast DLR' had similar motion artifact, as well as nerve conspicuity, signal intensity, size and morphology, with high inter-rater agreement (AC2: 'standard' = 0.70-0.98, 'fast DLR' = 0.69-0.97). CONCLUSION: DLR applied to faster, 3D MRN acquisitions provides similar image quality to standard scans. A faster, DL-enabled protocol may replace currently optimized non-DL protocols.

Subcutaneous injection of lidocaine around ischemic ankle provides safe and effective foot analgesia in patients with critical limb ischemia.

OBJECTIVE: It is often difficult to alleviate foot pain associated with critical limb ischemia (CLI) using common analgesics. Neuraxial block is contraindicated in anticoagulant therapy. This study was designed to determine the response to subcutaneous injection of lidocaine around the network of peripheral nerves around the ankle in patients with CLI pain on anticoagulants and antiplatelets. METHODS: Sixteen patients with CLI pain in the foot were enrolled in this double-blind placebo-controlled crossover study. Patients were randomized to receive either 2% lidocaine or saline via catheters inserted into the subcutaneous area around the ankle. After recurrence of pain, the patients were crossed over to receive the alternative treatment. Pain was assessed with a numerical rating scale (NRS) before and 15 min after injection. Patients used a descriptive scale to grade pain control and were asked to determine the duration of analgesia in each arm of the study. RESULTS: No serious complications including protracted bleeding occurred. Lidocaine significantly decreased the NRS on movement from 10 (6, 10) [median (range)] to 2 (0, 10) (p < .001), and the differences in the Δ change in NRS between lidocaine and placebo were significant (p = .009). Of the 16 patients, 14 patients were very satisfied after lidocaine but only one described the same after saline. The effect of lidocaine and placebo lasted 11 (0, 28) and 1 (0, 22) h, respectively. CONCLUSION: Subcutaneous injection of lidocaine around the ischemic ankle affectively alleviated pain in patients with CLI without serious adverse effects under anticoagulant therapy.

Vascular supply of the radial nerve and its terminal branches: an anatomical study.

PURPOSE: The aim of this cadaveric study was to further describe the vascular supply of the radial, posterior interosseous and superficial radial nerves. METHODS: 11 cadaveric upper limbs, injected with colored latex, were dissected. Vascular afferents to the radial nerve, superficial radial nerve (SRN) and posterior interosseous nerve (PIN) were described and located. Their origin was identified and its distance to interepicondylar line was measured. RESULTS: The radial nerve had an average of 3 vascular afferents (1-5), of septomuscular origin in 54% of cases. 46% came from adjacent arteries. The PIN had an average of 8 vascular afferents (6-14), arising from septomuscular branches in 82% of cases. The PIN was vascularized in 100% of cases by a large arterial plexus originating from the supinator muscle between its two heads. The SRN had an average of 4 vascular afferents (3-7). Before crossing the septum of the brachioradialis, vascularization was predominantly septomuscular; after crossing the septum, the nerve was exclusively vascularized by septocutaneous arteries. CONCLUSION: This is the first study to describe the vascularization of the radial nerve and its terminal branches along their entire length. Our results are in line with the data available in the literature. An arterial plexus between the two heads of the supinator was surrounding the PIN in all cases. This vascular plexus might be involved in dynamic compression of the posterior interosseous nerve.

Study on the relationship between peripheral nerve fiber types and levodopa usage in Parkinson's disease.

Background and purpose:

The aim of this study is to comprehensively determine the types of affected fibers in Parkinson’s disease (PD) patients by employing nerve conduction studies (NCS), sympathetic skin response (SSR) examinations, and current perception threshold (CPT) testing and to analyze the correlation between levodopa use and nerve involvement.

This retrospective study included 36 clinically diagnosed PD patients who were recruited between January 2018 and April 2019. All patients underwent NCS, SSR testing, and CPT sensory examinations. Additionally, the PD patients were assessed for disease staging using the Hoehn and Yahr (H-Y) scale. 

Fifteen patients were included in the tremor-dominant subtype, ten patients in the rigid-dominant subtype, and eleven patients in the mixed subtype. Eleven patients were using levodopa, while twenty-five patients had never used any anti-Parkinson’s medication. Ten patients (28%) showed abnormal sympathetic skin responses (SSR). The CPT examination revealed sensory abnormalities in twenty-four patients (67%), with eighteen patients (75%) experiencing sensory hypersensitivity and six patients (25%) experiencing sensory hypoesthesia. Twelve patients (33%) had normal CPT results. Among the patients with abnormal CPT findings, seven cases (29%) involved large myelinated fiber damage, twenty-two cases (92%) involved small myelinated fiber damage, and nineteen cases (79%) involved unmyelinated fiber damage. The rate of sensory abnormalities was 64% (7/11) in the levodopa group and 68% (17/25) in the non-levodopa group, with no statistically significant difference between the two groups. 

The incidence of abnormal CPT findings in PD patients was higher than that of abnormal SSR responses, suggesting that nerve fiber damage primarily affects small fiber nerves (SFN).

[Discussion on the relationship between pathological changes of sciatic nerve and Sarm1 protein expression in rats with n-hexane poisoning].

Objective: To explore the potential evidence of active peripheral nerve necrosis when n-hexane produces toxic effects on peripheral nerves. Methods: In May 2023, 36 SPF grade SD male rats with a body weight of 200-220 g were divided into 4 groups with 9 rats in each group and given normal saline and different doses of n-hexane (168, 675, 2 700 mg/kg) by gavage for 6 consecutive weeks (5 days/week). Three rats in each group were killed at the 2nd, 4th and 6th week, respectively. The spinal cord to sciatic nerve tissue was broken and the supernatant was extracted for SDS-PAGE protein isolation. The expression level of Sarm1 protein was analyzed with the ß-Actin color strip of internal reference protein by Western blot. The expression of Sarm1 protein was analyzed by the gray ratio of the two. At the 6th week, the sciatic nerve sections of the each group were observed by light microscope and electron microscope. Results: The number of axons was obviously reduced by light microscopy. According to electron microscope, myelin lesions were mainly local disintegration, deformation, and different thickness. The deformation of axonal surface became smaller. The axons in the nerve bundle membrane showed degeneration and reduction. The gray ratio of Sarm1 protein and internal reference protein bands in each group had no significant change at the second week of exposure, and the ratio of SARM1 protein to internal reference protein bands was 1.47 in the high dose group at the fourth week, and 1.51 and 1.89 in the middle and high dose group at the sixth week, respectively. Conclusion: Waller's degeneration was observed in sciatic neuropathologic manifestations of n-hexane-poisoned rats, and the expression level of Sarm1 protein increased.

[Peripheral nerves' function recovery by intratissual electric stimulation]. / Vosstanovlenie funktsii perifericheskikh nervov vnutritkanevoi elektrostimulyatsiei.

An intratissual electrical stimulation, accompanied by irritation of their central neurons, is used to recover the function of damaged peripheral nerves. Treatment results exceeded those with the use of cutaneous electrical stimulation, which is confirmed by comparative results of trial animal experiments. The time and quality of peripheral nerves' function recovery in comparison of intratissual and cutaneous electrical stimulation methods remain unknown. OBJECTIVE: To evaluate the time and quality of peripheral nerves' functions recovery after their suturing and conducting two different methods of electrical stimulation, namely intratissual and cutaneous, in projection of central neurons of damaged spinal nerves in the postoperative period. MATERIAL AND METHODS: The basic technical parameters of the method of peripheral nerves' functions recovery in the postoperative period were ptacticed. Postoperative rehabilitation treatment was performed in 77 patients with traumatic peripheral nerves' injuries at the level of the forearm: in 42 with intratissual electrical stimulation, in 35 - using cutaneous one with similar characteristics of electrical current and concomitant pharmacological therapy. The follow-up duration was 2 years. RESULTS: A significant (in 4-6 times) reduction in time of treatment and a greater improvement in qualitative indicators when using intratissual electrical stimulation compared to the use of cutaneous stimulation were obtained. The effectiveness of the restorative therapy was dependent on the number of procedures, and a complete recovery of the damaged peripheral nerves' functions was observed after three courses of intratissual electrical stimulation. CONCLUSION: The time and degree of recovery of peripheral nerves' functions depends on the functional activity of their central neurons at the level of the spinal cord. The activation of these neurons by low-frequency electrical current allows to activate their trophic function. Thus, the cutaneous electrical stimulation does not cause the necessary level of irritation of the neurons due to the fact that the skin is a barrier to electrical current, which reduces its impact in 200-500 times. The intratissual electrical stimulation allows to solve the problem by supplying the needle-electrode much closer to the «target¼. The proposed method of intratissual electrical stimulation has shown its advantage over cutaneous electrical stimulation, significantly reducing the duration of the restorative treatment and increasing its qualitative indicators.

Central and Peripheral Nervous System Complications of Vasculitis Syndromes from Pathology to Bedside: Part 2-Peripheral Nervous System.

PURPOSE OF REVIEW: Peripheral nervous system vasculitides (PNSV) are a heterogeneous group of disorders with a clinical subset that may differ in prognosis and therapy. We provide a comprehensive update on the clinical assessment, diagnosis, complications, treatment, and follow-up of PNSV. RECENT FINDINGS: Progress in neuroimaging, molecular testing, and peripheral nerve biopsy has improved clinical assessment and decision-making of PNSV, also providing novel insights on how to prevent misdiagnosis and increase diagnostic certainty. Advances in imaging techniques, allowing to clearly display the vessel walls, have also enhanced the possibility to differentiate inflammatory from non-inflammatory vascular lesions, while recent histopathology data have identified the main morphological criteria for more accurate diagnosis and differential diagnoses. Overall, the identification of peculiar morphological findings tends to improve diagnostic accuracy by defining a clearer boundary between systemic and non-systemic neuropathies. Therefore, the definition of epineurium vessel wall damage, type of vascular lesion, characterization of lymphocyte populations, antibodies, and inflammatory factors, as well as the identification of direct nerve damage or degeneration, are the common goals for pathologists and clinicians, who will both benefit for data integration and findings translation. Nevertheless, to date, treatment is still largely empiric and, in some cases, unsatisfactory, thus often precluding precise prognostic prediction. In this context, new diagnostic techniques and multidisciplinary management will be essential in the proper diagnosis and prompt management of PNSV, as highlighted in the present review. Thirty to fifty percent of all patients with vasculitis have signs of polyneuropathy. Neuropathies associated with systemic vasculitis are best managed according to the guidelines of the underlying disease because appropriate workup and initiation of treatment can reduce morbidity. Steroids, or in severe or progressive cases, cyclophosphamide pulse therapy is the standard therapy in non-systemic vasculitic neuropathies. Some patients need long-term immunosuppression. The use of novel technologies for high-throughput genotyping will permit to determine the genetic influence of related phenotypes in patients with PNSV.

Peripheral Tubercular Neuritis.

Peripheral neuropathy can affect sensory, motor, or autonomic nerves and manifest with a variety of symptoms. Tuberculosis as a major infectious disease that often affects many organs of the body. However, primary involvement of peripheral nerves is unusual. Peripheral neuropathy in patients with tuberculosis often is associated with other comorbidities, such as immunocompromised states, diabetes mellitus, malnutrition, and some antitubercular medications. This report describes the rare finding of peripheral tubercular neuritis with caseating abscesses of right median and radial nerve in a healthy 24-year man.

Lacertus syndrome: a ten year analysis of two hundred and seventy five minimally invasive surgical decompressions of median nerve entrapment at the elbow.

PURPOSE: This study aims to assess the clinical presentation and surgical outcomes of lacertus syndrome (LS) and concomitant median nerve entrapments. METHODS: A retrospective study of prospectively collected data was conducted on patients undergoing lacertus release (LR) from June 2012 to June 2021. Available DASH (Disability of the Arm Shoulder Hand questionnaire) scores and post-operative Visual Analogue Scale (VAS) of pain, numbness, subjective satisfaction with surgical outcome, and intra-operative return of strength were analyzed. RESULTS: Two-hundred-seventy-five surgical cases were identified of which 205 cases (74.5%) underwent isolated LR, and 69 cases (25.1%) concomitant lacertus and carpal tunnel release. The three most common presenting symptoms in LS patients were loss of hand strength (95.6%), loss of hand endurance/fatigue (73.3%), and forearm pain (35.4%). Numbness in the median nerve territory of the hand was found in all patients with combined LS and carpal tunnel syndrome. Quick-DASH significantly improved (pre-operative 34.4 (range 2.3-84.1) to post-operative 12.4 (range 0-62.5), p < 0.0001) as did work and activity DASH (p < 0.0001). The postoperative VAS scores were pain VAS 1.9 and numbness VAS 1.8. Eighty-eight percent of patients reported good/excellent satisfaction with the surgical outcome. Intra-operative return of strength was verified in 99.2% of cases. CONCLUSION: LS is a common median nerve compression syndrome typically presenting with loss of hand strength and hand endurance/fatigue. Minimally invasive LR immediately restores hand strength, significantly improves DASH scores, and yields positive outcomes regarding VAS pain, numbness, and subjective satisfaction with surgery in patients with proximal median nerve entrapment at a minimum six month follow-up.

Anatomical patterns of the sural nerve: a meta-analysis with clinical and surgical considerations.

BACKGROUND: The sural nerve (SN) supplies the posterolateral aspect of the leg and the lateral aspects of the ankle and foot and descends through the gastrocnemius muscle along the lower third of leg. Because in-depth knowledge about SN anatomy is essential for clinical and surgical approaches, our study aims to review SN anatomical patterns. METHODS: We searched the PubMed, Lilacs, Web of Science, and SpringerLink databases to find relevant articles for meta-analysis. We assessed the quality of the studies using the Anatomical Quality Assessment tool. We used proportion meta-analysis to analyze the SN morphological variables and simple mean meta-analysis to analyze the SN morphometric variables (nerve length and distance to anatomical landmarks). RESULTS: Thirty-six studies comprised this meta-analysis. Overall, Type 2A (63.68% [95% CI 42.36-82.64]), Type 1A (51.17% [95% CI 33.16-69.04]) and Type 1B (32.19% [95% CI 17.83-48.38]) were the most common SN formation patterns. The lower third of leg (42.40% [95% CI 32.24-52.86]) and middle third of leg (40.00% [95% CI 25.21-53.48]) were the most common SN formation sites. The pooled SN length from nerve formation to the lateral malleolus was 144.54 mm (95% CI 123.23-169.53) in adults, whereas the SN length was 25.10 mm (95% CI 23.20-27.16) in fetuses in the second trimester of gestation and 34.88 mm (95% CI 32.86-37.02) in fetuses in the third trimester of gestation. CONCLUSIONS: The most prevalent SN formation pattern was the union of the medial sural cutaneous nerve with the lateral sural cutaneous nerve. We found differences regarding geographical subgroup and subject age. The most common SN formation sites were the lower and middle thirds of the leg.

[Ultrasound examination of nerves of the upper extremities]. / Nervensonographie der oberen Extremitäten.

The ultrasound examination of peripheral nerves has been further developed in recent years and is recognized as an independent discipline by the German Society of Ultrasound in Medicine (DEGUM). A systematic ultrasound examination of the musculoskeletal system is not limited to the joints, muscles and bones but should also include the examination of nerves and blood vessels. Therefore, in the practice of ultrasound examination every rheumatologist should have at least a basic knowledge of the ultrasound examination of the peripheral nerves. In this article the authors present a landmark-based concept in which the three large nerves of the upper extremities can be completely visualized from proximal to distal and evaluated.

[Secondary surgical procedures following motor nerve injuries]. / Sekundäre operative Verfahren bei Verletzungen motorischer Nerven.

BACKGROUND: The functional deficits that develop after a peripheral nerve injury mean a considerable reduction in the quality of life for the affected patients. However, interventions on the injured nerve are not always possible or effective. In this case, secondary procedures, e.g. tendon transfers, are a feasible option for functional reconstruction. OBJECTIVES: An overview of the most common secondary surgical procedures for functional reconstruction after peripheral nerve injuries. METHODS: Presentation and discussion of the most common secondary surgical procedures with emphasis on tendon transfers. Illustration of the primary functions that need to be reconstructed depending on the respective nerve lesion. RESULTS: The basic principle of secondary surgical procedures after nerve injuries is the transposition of a healthy tendomuscular unit to replace a lost function following a loss of muscle or tendon or if an intervention on the nerve is not promising. For example, by transferring flexor forearm muscles, wrist, finger and thumb extension can be reconstructed after radial nerve injury. By transposing the tibialis posterior muscle, dorsiflexion in the talocrural joint can be restored to enable the affected patient to walk safely without an orthosis. CONCLUSIONS: Secondary surgical procedures are a valuable option for functional reconstruction after nerve injury.

[Choosing the right imaging for the diagnostics and assessment of the course of peripheral nerve injuries]. / Die Wahl der richtigen Bildgebung zur Diagnostik und Verlaufsbeurteilung peripherer Nervenverletzungen.

BACKGROUND: Nerve injuries are a frequent problem in routine clinical practice and require intensive interdisciplinary care. OBJECTIVE: The current status of imaging to confirm the diagnosis of nerve injuries is described. The role of high-resolution ultrasound and magnetic resonance imaging (MRI) in the diagnostics and follow-up of peripheral nerve injuries is elaborated. MATERIAL AND METHODS: Review of the current state of imaging to confirm the diagnosis of nerve injuries. RESULTS: Depending on the suspected site of damage, the primary domain of magnetic resonance (MR) imaging (MR neurography) is injuries in the region of the spine, nerve roots, brachial plexus and lumbar plexus, pelvis and proximal thigh. In contrast, in other peripheral nerve lesions of the extremities the advantages of high-resolution nerve ultrasound in a dynamic setting predominate. The MR neurography is indicated here, especially in the frequent bottleneck syndromes and only in very isolated and selected cases. CONCLUSION: In addition to a correct anatomical assignment, the timely decision for a possible intervention and the appropriate concomitant treatment are an important basis for a favorable prognosis of nerve injuries. Imaging techniques should therefore be used early in the diagnostics and follow-up controls of peripheral nerve injuries.

Safety in Dermatologic Procedures: Accidental Injury to Major Blood Vessels and Nerve Structures. / Seguridad en procedimientos dermatológicos: sección de grandes vasos sanguíneos y estructuras nerviosas.

This article in the series «Safety in Dermatologic Procedures¼ deals with the accidental laceration of major blood vessels and nerve structures during surgery. We first look at the anatomic location and course of the blood vessels and nerve structures that are most at risk of injury and then describe the possible outcomes in each case. We finally offer some recommendations on how to avoid damage to structures in danger zones and how to repair them if they are accidentally compromised.