Rehabilitation Surgery for Peripheral Facial Nerve Injury after Facial Trauma.

Introduction Facial trauma can cause damage to the facial nerve, which can have negative effects on function, aesthetics, and quality of life if left untreated. Objective To evaluate the effectiveness of peripheral facial nerve direct end-to-end anastomosis and/or nerve grafting surgery for patients with facial nerve injury after facial trauma. Methods Fifty-nine patients with peripheral facial nerve paralysis after facial injuries underwent facial nerve rehabilitation surgery from November 2017 to December 2021 at Ho Chi Minh City National Hospital of Odontology. Results All 59 cases of facial trauma with damage to the peripheral facial nerve underwent facial nerve reconstruction surgery within 8 weeks of the injury. Of these cases, 25/59 (42.3%) had end-to-end anastomosis, 22/59 (37.3%) had nerve grafting, and 12/59 (20.4%) had a combination of nerve grafting and end-to-end anastomosis. After surgery, the rates of moderate and good recovery were 78.4% and 11.8%, respectively. All facial paralysis measurements showed statistically significant improvement after surgery, including the Facial Nerve Grading Scale 2.0 (FNGS 2.0) score, the Facial Clinimetric Evaluation (FaCE) scale, and electroneurography. The rate of synkinesis after surgery was 34%. Patient follow-up postoperatively ranged from 6 to > 36 months; 51 out of 59 patients (86.4%) were followed-up for at least 12 months or longer. Conclusion Nerve rehabilitation surgery including direct end-to-end anastomosis and nerve grafting is effective in cases of peripheral facial nerve injury following facial trauma. The surgery helps restore nerve conduction and improve facial paralysis.

Superficial retrocalcaneal bursae and nerves: From anatomy to ultrasound-guided procedures.

The pertinent literature widely describes ultrasound-guided procedures targeting the retrocalcaneal bursa and the tendon tissue to manage insertional Achilles tendinopathy. Synovial bursae and cutaneous nerves of the superficial retrocalcaneal pad are often overlooked pain generators and are poorly considered by clinicians and surgeons. A layer-by-layer dissection of the superficial soft tissues in the retrocalcaneal region of two fresh frozen cadavers was matched with historical anatomical tables of the textbook Traite d'Anatomie Topographique Avec Applications Médico-Chirurgicales (1909 by Testut and Jacob). An accurate and detailed description of the superficial retrocalcaneal pad with its synovial bursae and cutaneous nerves was provided. Cadaveric dissections confirmed the compartmentalized architecture of the superficial retrocalcaneal fat pad and its histological continuum with the superficial lamina of the crural fascia. Superficial synovial tissue islands have been demonstrated on the posterior aspect of the Achilles tendon in one cadaver and on the posterolateral surface of the tendon in the other one. Digitalization of the original anatomical tables of the textbook Traite d'Anatomie Topographique Avec Applications Médico-Chirurgicales (1909 by Testut and Jacob) showed five potential locations of the superficial calcaneal bursa and a superficial retrocalcaneal nerve plexus within the Achilles tendon-fat pad interface. In clinical practice, in addition to the previously described interventions regarding the retrocalcaneal bursa and the tendon tissue, ultrasound-guided procedures targeting the synovial and neural tissues of the superficial retrocalcaneal pad should be considered to optimize the management of insertional Achilles tendinopathy.

Multiple Mini Incision Technique for Sural Nerve Harvest: When to Add a Fibular Incision Based on a New Surgical Classification.

Sural nerve is the most common nerve used as a source for nerve grafting. Open harvest with longitudinal incisions produces unsightly scars, and this have led to development of less invasive techniques using endoscopes, nerve stripper, and mini-incisions. Several anatomical classifications have also been proposed due to the variations in the anatomy of the sural nerve. A simple and practical surgicoanatomical classification of the sural nerve based on which we have refined our minimal access technique, the multiple mini-incision technique for sural nerve harvest is proposed. In this technique, the incisions required for harvest of the sural nerve are standardized and predictable. A fibular incision is required when the sural nerve has major contribution from the common peroneal nerve. We have found this a simpler and reliable technique of harvest of sural nerve in nerve reconstructive surgery.

Role of tactile stimulation during the preweaning period on the development of the peripheral sensory sural (SU) nerve in adult artificially reared female rat.

Maternal deprivation, as a result of the artificial rearing (AR) paradigm, disturbs electrophysiological and histological characteristics of the peripheral sensory sural (SU) nerve of infant and adult male rats. Such changes are prevented by providing tactile or social stimulation during isolation. AR also affects the female rat's brain and behavior; however, it is unknown whether this early adverse experience also alters their SU nerve development or if tactile stimulation might prevent these possible developmental effects. To assess these possibilities, the electrophysiological and histological characteristics of the SU nerve from adult diestrus AR female rats that: (i) received no tactile stimulation (AR group), (ii) received tactile stimulation in the anogenital and body area (AR-Tactile group), or (iii) were mother reared (MR group) were determined. We found that the amplitude, but not the area, of the evoked compound action potential response in SU nerves of AR rats was lower than those of SU nerves of MR female rats. Tactile stimulation prevented these effects. Additionally, we found a reduction in the outer diameter and myelin thickness of axons, as well as a large proportion of axons with low myelin thickness in nerves of AR rats compared to the nerves of the MR and AR-Tactile groups of rats; however, tactile stimulation only partially prevented these effects. Our data indicate that maternal deprivation disturbs the development of sensory SU nerves in female rats, whereas tactile stimulation partially prevents the changes generated by AR. Considering that our previous studies have shown more severe effects of AR on male SU nerve development, we suggest that sex-associated factors may be involved in these processes.

Cross-Sectional Study of the Relationship Between Medial Plantar Nerve Conduction Studies and Severity of Diabetic Neuropathy.

Objective: Diabetic peripheral neuropathy (DPN), a complication of diabetes, is detected only in later stages. Medial plantar nerve (MPL) can identify earlier stages of neuropathy. We evaluated the correlation of MPL sensory nerve action potentials (SNAPs) and severity of DPN measured using the Toronto Clinical Neuropathy Score (TCNS). Methods: In this hospital-based, cross-sectional study, we recruited diabetic subjects referred for suspected DPN. Neuropathy was graded with TCNS. Sural nerve conduction studies were performed using standard techniques. MPL studies were conducted using the modified Ponsford technique. All evaluations were performed on Nihon Kohden (model MEB 9200K). Averaged MPL SNAP was correlated with TCNS using Pearson's correlation coefficient. To estimate a correlation of 0.4 with 80% power (P = 0.05), we needed 46 subjects. Linear regression was conducted to adjust for age, duration, and diabetic control. Receiver operating characteristic (ROC) curve analysis was performed to obtain the cutoff for MPL SNAP values using the Youden index. Results: Fifty-one subjects with a mean age of 53.5 years (8.7) and mean duration of diabetes of 10.2 years (7.2) were included. MPL SNAPs were recordable in 12 patients, and the mean amplitude was 5.15 (2.9) µV. There was correlation between MPL SNAP and TCNS (r = -0.43, P = 0.02). No confounding was seen. Use of MPL SNAP resulted in diagnosis of DPN in an additional six (11.8%) patients. The ROC curve suggested that MPL SNAP cutoff of 1.05 µV had an accuracy of 67% in identifying neuropathy as defined by TCNS. Conclusions: MPL SNAP has a moderate correlation with clinical score and identifies more diabetic neuropathy than sural nerve.

Peritendinous Submembrane Access Technique for Management of Acute Ruptures of the Achilles Tendon: A Retrospective Study of 249 Cases.

OBJECTIVE: Percutaneous repair is an alternative to open surgical repair of the Achilles tendon with comparable, functional results and low re-rupture and infection rates; however, sural nerve injury is a known complication. The purpose of this study is to design a new surgical procedure, the minimally invasive peritendinous submembrane access technique (MIS-PSAT). It offers optimal results, with excellent functional outcomes, and with minimal soft tissue complications and sural nerve injury. METHODS: This retrospective study included 249 patients with acute closed Achilles tendon ruptures treated at our institution between 2009 and 2019. All patients underwent MIS-PSAT at our institution and were followed up for 8-48 months. Functional evaluation was based on the Achilles tendon total rupture score (ATRS) and the American Orthopedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS-AHS), associated with local complications and isokinetic tests. RESULTS: None of the patients had infection, necrosis, or sural nerve injury. Re-rupture occurred in two cases. The average times to return to work and sports was 10.4 and 31.6 weeks, respectively. The average ATRS and AOFAS-AHS scores were 90.2 and 95.7, respectively, with an excellent rate of 99.5%. Isokinetic tests showed that ankle function on the affected side was comparable with that on the healthy side (p > 0.05). CONCLUSION: The MIS-PSAT for acute Achilles tendon rupture is easy to perform with few complications. Importantly, the surgical technique reduces the risk of sural nerve injuries. Patients have high postoperative satisfaction, low re-rupture rates, and muscle strength, and endurance can be restored to levels similar to those on the healthy side.

A Bilateral Symmetrical Variant Formation of the Sural Nerve.

Typically, the sural nerve is formatted by the connection of the lateral sural cutaneous nerve (branch of the common fibular nerve) and the medial sural cutaneous nerve (branch of the tibial nerve). The current cadaveric report aims to describe a quite unusual symmetrical variant of the sural nerve. Classical dissection was performed on an 84-year-old donated male cadaver. On both sides, the sural nerve was formatted directly by the sciatic nerve. After its emanation, it continued its typical course between the gastrocnemius muscle heads. Sural nerve formation has been extensively studied due to its great clinical significance. The identified variant corresponds to one of the rarest types of sural nerve formation. Knowledge of sural nerve variants may play a crucial role in lower limb surgery and nerve harvest for reconstruction.

A Rare Atypical Case of Asymptomatic and Spontaneous Intraneural Hematoma of Sural Nerve: A Case Report and Literature Review.

Intraneural hematoma is a rare disease that results in an impaired nerve function because of bleeding around the peripheral nerve, with only 20 cases reported. Trauma, neoplasm, and bleeding disorders are known factors for intraneural hematoma. However, here we report atypical features of asymptomatic and spontaneous intraneural hematoma which are difficult to diagnose. A 60-year-old woman visited our clinic with the complaint of a palpable mass on the right calf. She reported no medical history or trauma to the right calf and laboratory findings showed normal coagulopathy. Ultrasonography was performed, which indicated hematoma near saphenous vein and sural nerve or neurogenic tumor. We performed surgical exploration and intraneural hematoma was confirmed on sural nerve. Meticulous paraneuriotomy and evacuation was performed without nerve injury. Histological examination revealed intraneural hematoma with a vascular wall. No neurologic symptoms were observed. In literature review, we acknowledge that understanding anatomy of nerve, using ultrasonography as a diagnostic tool and surgical decompression is key for intraneural hematoma. Our case report may help establish the implications of diagnosis and treatment. Also, we suggested surgical treatment is necessary even in cases that do not present symptoms because neurological symptoms and associated symptoms may occur later.

Automated whole slide morphometry of sural nerve biopsy using machine learning.

AIM: The morphometry of sural nerve biopsies, such as fibre diameter and myelin thickness, helps us understand the underlying mechanism of peripheral neuropathies. However, in current clinical practice, only a portion of the specimen is measured manually because of its labour-intensive nature. In this study, we aimed to develop a machine learning-based application that inputs a whole slide image (WSI) of the biopsied sural nerve and automatically performs morphometric analyses. METHODS: Our application consists of three supervised learning models: (1) nerve fascicle instance segmentation, (2) myelinated fibre detection and (3) myelin sheath segmentation. We fine-tuned these models using 86 toluidine blue-stained slides from various neuropathies and developed an open-source Python library. RESULTS: Performance evaluation showed (1) a mask average precision (AP) of 0.861 for fascicle segmentation, (2) box AP of 0.711 for fibre detection and (3) a mean intersection over union (mIoU) of 0.817 for myelin segmentation. Our software identified 323,298 nerve fibres and 782 fascicles in 70 WSIs. Small and large fibre populations were objectively determined based on clustering analysis. The demyelination group had large fibres with thinner myelin sheaths and higher g-ratios than the vasculitis group. The slope of the regression line from the scatter plots of the diameters and g-ratios was higher in the demyelination group than in the vasculitis group. CONCLUSION: We developed an application that performs whole slide morphometry of human biopsy samples. Our open-source software can be used by clinicians and pathologists without specific machine learning skills, which we expect will facilitate data-driven analysis of sural nerve biopsies for a more detailed understanding of these diseases.

Anatomical considerations of the sural nerve in the distal leg: Side branch patterns and significance in nerve harvesting procedures.

BACKGROUND: The sural nerve is a somatosensory nerve that provides sensation to the posterolateral aspect of the lower leg and the lateral part of the ankle and foot. Due to its location and anatomical properties, it is often used as an autologous nerve graft. However, the nerve harvest can be complicated by the presence of side branches. The objective of this study was to investigate the anatomy of the sural nerve and to map its side branches. This information can be used to predict the localization of separate incisions during the stair-step incisions technique for nerve harvest, thereby reducing the risk of complications. METHODS: The study involved the dissection of 50 adult cadaveric legs (25 left and 25 right) obtained from 27 Central European cadavers. The focus of the dissection was to identify the sural nerve, small saphenous vein, and surrounding anatomical structures. Detailed measurements were taken on the side branches of the sural nerve, tributaries of the small saphenous vein, and their interrelationship. RESULTS: The average number of sural nerve side branches in a single leg was 4.2±1.9. These side branches were categorized into six groups based on their location and course: mediodistal, medioproximal, lateroproximal, laterodistal, medial perpendicular, and lateral perpendicular. Specific patterns of combination of these side branches were also identified and described. The branching point of the sural nerve was found to be 5.8±2.7 cm proximal to the lateral malleolus, whereas the small saphenous vein branching point was located more distally, 4.5 ± 2.8 cm proximal to the lateral malleolus. The highest density of sural nerve side branches was found 2.1-6.0 cm above the lateral malleolus. CONCLUSION: This study presents valuable data about the relationship between the sural nerve and the surrounding anatomical structures in the distal part of the leg, including the identification of its side branches and their relevance during nerve harvest procedures. On the basis of the most frequent locations of side branches, a three-incision-technique for nerve harvest is proposed.

Ultrahigh-frequency ultrasound of fascicles in the common fibular, superficial fibular, and sural nerves.

INTRODUCTION/AIMS: While ultrasound assessment of cross-sectional area and echogenicity has gained popularity as a biomarker for various neuropathies, there is a scarcity of data regarding fascicle count and density in neuropathies or even healthy controls. The aim of this study was to determine whether fascicles within select lower limb nerves (common fibular, superficial fibular, and sural nerves) can be counted in healthy individuals using ultrahigh-frequency ultrasound (UHFUS). METHODS: Twenty healthy volunteers underwent sonographic examination of the common fibular, superficial fibular, and sural nerves on each lower limb using UHFUS with a 48 MHz linear transducer. Fascicle counts and density in each examined nerve were determined by a single rater. RESULTS: The mean fascicle number for each of the measured nerves included the following: common fibular nerve 9.85 (SD 2.29), superficial fibular nerve 5.35 (SD 1.59), and sural nerve 6.73 (SD 1.91). Multivariate linear regression analysis revealed a significant association between cross-sectional area and fascicle count for all three nerves. In addition, there was a significant association seen in the common fibular nerve between fascicle density and height, weight, and body mass index. Age and sex did not predict fascicle count or density (all p > .13). DISCUSSION: UHFUS enabled the identification and counting of fascicles and fascicle density in the common fibular, superficial fibular, and sural nerves. Knowledge about normal values and normal peripheral nerve architecture is needed in order to further understand and identify pathological changes that may occur within each nerve in different disease states.

Morphometry of the sural nerve in diabetic neuropathy: a systematic review.

PURPOSE: The aim of this systematic review is to evaluate the usefulness of sural nerve ultrasonography in diagnosing diabetes mellitus (DM) and diabetic polyneuropathy (DPN), the latter of which is a common long-term complication for diabetic patients that frequently involves the sural nerve. METHODOLOGY: A meta-analysis of the cross-sectional areas (CSAs) of sural nerves in healthy individuals and patients with diabetes mellitus based on a total of 32 ultrasonographic-based studies from 2015 to 2023 was performed. Sub-analyses were performed for factors such as geographical location and measurement site. RESULTS: The meta-analysis showed that the mean CSA of the sural nerve was significantly larger in DM patients with DPN only compared to healthy individuals across all regions and when pooled together. An age-dependent increase in the CSA of healthy sural nerves is apparent when comparing the paediatric population with adults. CONCLUSION: Sural nerve ultrasonography can distinguish diabetic adults with DPN from healthy adults based on cross-sectional area measurement. Future studies are needed to clarify the relationships between other parameters, such as body metrics and age, with sural nerve CSAs. Cut-offs for DPN likely need to be specific for different geographical regions.

Utilization of the Rat Tibial Nerve Transection Model to Evaluate Cellular and Molecular Mechanisms Underpinning Denervation-Mediated Muscle Injury.

Peripheral nerve injury denervates muscle, resulting in muscle paralysis and atrophy. This is reversible if timely muscle reinnervation occurs. With delayed reinnervation, the muscle's reparative ability declines, and muscle-resident fibro-adipogenic progenitor cells (FAPs) proliferate and differentiate, inducing fibro-fatty muscle degradation and thereby physical disability. The mechanisms by which the peripheral nerve regulates FAPs expansion and differentiation are incompletely understood. Using the rat tibial neve transection model, we demonstrated an increased FAPs content and a changing FAPs phenotype, with an increased capacity for adipocyte and fibroblast differentiation, in gastrocnemius muscle post-denervation. The FAPs response was inhibited by immediate tibial nerve repair with muscle reinnervation via neuromuscular junctions (NMJs) and sensory organs (e.g., muscle spindles) or the sensory protection of muscle (where a pure sensory nerve is sutured to the distal tibial nerve stump) with reinnervation by muscle spindles alone. We found that both procedures reduced denervation-mediated increases in glial-cell-line-derived neurotrophic factor (GDNF) in muscle and that GDNF promoted FAPs adipogenic and fibrogenic differentiation in vitro. These results suggest that the peripheral nerve controls FAPs recruitment and differentiation via the modulation of muscle GDNF expression through NMJs and muscle spindles. GDNF can serve as a therapeutic target in the management of denervation-induced muscle injury.

Heel Pain Management in Haglund's Deformity Targeting Sural Nerve Branches under Ultrasound Guidance: Case Report.

Introduction: Haglund's deformity is an abnormality of the bone and soft tissue of the foot, also known as retrocalcaneal exostosis, Mulholland deformity, and "pump bump". The etiology is not well known. Probable causes include a tight Achilles tendon, a high arch of the foot, and hereditary. The clinical features consist of pain at the posterior aspect of the heel which is predominantly present when the patient begins to walk after a period of rest or inactivity. Case Report: We report a case of a 60-year-old teacher with left heel pain for 3 years, unable to stand or walk for more than 15 min due to pain. We diagnosed him as a case of Haglund's deformity and treated him with ultrasound-guided injections targeting the superficial branches of the sural nerve. This case report illustrates a rarely described modality for the management of heel pain due to Haglund's deformity. Targeting superficial branches of the Sural nerve under ultrasound guidance can act as a superior treatment modality for the management of heel pain due to Haglund's deformity. Conclusion: Haglund's deformity is a cause of pain in the hindfoot that should be taken into account in the differential diagnosis of any patient presenting with heel pain. Ultrasonography has proved to be an important cost-effective tool in the diagnosis and management of various ankle pathologies like Haglund's deformity, thereby reducing the sole dependence on surgical management. Targeting the superficial (cutaneous) branches of the sural nerve can give satisfactory long-term relief of heel pain in patients with Haglund deformity.

Effects of exosomes from mesenchymal stem cells on functional recovery of a patient with total radial nerve injury: A pilot study.

BACKGROUND: Peripheral nerve injury can result in significant clinical complications that have uncertain prognoses. Currently, there is a lack of effective pharmacological interventions for nerve damage, despite the existence of several small compounds, peptides, hormones, and growth factors that have been suggested as potential enhancers of neuron regeneration. Despite the objective of achieving full functional restoration by surgical intervention, the persistent challenge of inadequate functional recovery remains a significant concern in the context of peripheral nerve injuries. AIM: To examine the impact of exosomes on the process of functional recovery following a complete radial nerve damage. METHODS: A male individual, aged 24, who is right-hand dominant and an immigrant, arrived with an injury caused by a knife assault. The cut is located on the left arm, specifically below the elbow. The neurological examination and electrodiagnostic testing reveal evidence of left radial nerve damage. The sural autograft was utilized for repair, followed by the application of 1 mL of mesenchymal stem cell-derived exosome, comprising 5 billion microvesicles. This exosome was split into four equal volumes of 0.25 mL each and delivered microsurgically to both the proximal and distal stumps using the subepineural pathway. The patient was subjected to a period of 180 d during which they had neurological examination and electrodiagnostic testing. RESULTS: The duration of the patient's follow-up period was 180 d. An increasing Tinel's sign and sensory-motor recovery were detected even at the 10th wk following nerve grafting. Upon the conclusion of the 6-mo post-treatment period, an evaluation was conducted to measure the extent of improvement in motor and sensory functions of the nerve. This assessment was based on the British Medical Research Council scale and the Mackinnon-Dellon scale. The results indicated that the level of improvement in motor function was classified as M5, denoting an excellent outcome. Additionally, the level of improvement in sensory function was classified as S3+, indicating a good outcome. It is noteworthy that these assessments were conducted in the absence of physical therapy. At the 10th wk post-injury, despite the persistence of substantial axonal damage, the nerve exhibited indications of nerve re-innervation as evidenced by control electromyography (EMG). In contrast to the preceding. EMG analysis revealed a significant electrophysiological enhancement in the EMG conducted at the 6th-mo follow-up, indicating ongoing regeneration. CONCLUSION: Enhanced comprehension of the neurobiological ramifications associated with peripheral nerve damage, as well as the experimental and therapy approaches delineated in this investigation, holds the potential to catalyze future clinical progress.

Selective neural inhibition via photobiomodulation alleviates behavioral hypersensitivity associated with small sensory fiber activation.

OBJECTIVE: Photobiomodulation at higher irradiances has great potential as a pain-alleviating method that selectively inhibits small diameter nerve fibers and corresponding sensory experiences, such as nociception and heat sensation. The longevity and magnitude of these effects as a function of laser irradiation parameters at the nerve was explored. METHODS: In a rodent chronic pain model (spared nerve injury-SNI), light was applied directly at the sural nerve with four delivery schemes: two irradiance levels (7.64 and 2.55 W/cm2 ) for two durations each, corresponding to either 4.8 or 14.4 J total energy, and the effect on sensory hypersensitivities was evaluated. RESULTS: At emitter irradiances of 7.64 W/cm2 (for 240 s), 2.55 W/cm2 (for 720 s), and 7.64 W/cm2 (for 80 s) the heat hypersensitivity was relieved the day following photobiomodulation (PBM) treatment by 37 ± 8.1% (statistically significant, p < 0.001), 26% ± 6% (p = 0.072), and 28 ± 6.1% (statistically significant, p = 0.032), respectively, and all three treatments reduced the hypersensitivity over the course of the experiment (13 days) at a statistically significant level (mixed-design analysis of variance, p < 0.05). The increases in tissue temperature (5.3 ± 1.0 and 1.3 ± 0.4°C from 33.3°C for the higher and lower power densities, respectively) at the neural target were well below those typically associated with permanent action potential disruption. CONCLUSIONS: The data from this study support the use of direct PBM on nerves of interest to reduce sensitivities associated with small-diameter fiber activity.

Landmarks for a Minimally Invasive Approach for Haglund's Deformity: A Cadaveric Study.

INTRODUCTION: Haglund's deformity is a posterosuperior calcaneal prominence often associated with a painful bursa and insertional Achilles tendinopathy. Endoscopic debridement has been previously described; however, the aim of this cadaveric study is to describe landmarks of a minimally invasive surgical (MIS) approach to Haglund's deformity. METHODS: Twelve specimens were dissected to identify medial and lateral portals for minimally invasive burr placement and anchor placement. A standard ruler was used to measure the distance in millimeters from the medial and lateral neurovascular structures in relation to medial and lateral portals. A separate 7-cm longitudinal incision posterior to the lateral malleolus and a separate 7-cm longitudinal incision posterior to the medial malleolus were made to identify at-risk neurovascular structures. RESULTS: The average distance from the sural nerve to the lateral portal was 25.7 mm (23-26). The mean distance from the lateral calcaneal branch of the sural nerve to lateral portal was 11.4 mm (10-12). The mean distance from the tibial nerve to the medial portal was 35.3 mm (35-36). Both the medial and lateral incisions were 9.3 mm from the calcaneal tuberosity. CONCLUSION: The results indicate that the MIS approach to Haglund's deformity resection can be performed reliably without neurovascular compromise. LEVELS OF EVIDENCE: Level IV.

The sural-sparing pattern in clinical variants and electrophysiological subtypes of Guillain-Barré syndrome / Padrão de preservação do sural nas variantes clínicas e subtipos eletrofisiológicos da síndrome de Guillain-Barré

Abstract Background Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis worldwide and can be classified into electrophysiological subtypes and clinical variants. Objective This study aimed to compare the frequency of the sural-sparing pattern (SSP) in subtypes and variants of GBS. Methods This retrospective cohort study analyzed clinical and electrophysiological data of 171 patients with GBS hospitalized in public and private hospitals of Natal, Rio Grande do Norte, Brazil, between 1994 and 2018; all cases were followed up by the same neurologist in a reference neurology center. Patients were classified according to electrophysiological subtypes and clinical variants, and the SSP frequency was compared in both categories. The exact Fisher test and Bonferroni correction were used for statistical analysis. Results The SSP was present in 53% (57 of 107) of the patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 8% (4 of 48) of the patients with axonal subtypes, and 31% (5 of 16) of the equivocal cases. The SSP frequency in the AIDP was significantly higher than in the axonal subtypes (p < 0.0001); the value was kept high after serial electrophysiological examinations. Only the paraparetic subtype did not present SSP. Conclusion The SSP may be present in AIDP and axonal subtypes, including acute motor axonal neuropathy, but it is significantly more present in AIDP. Moreover, the clinical variants reflect a specific pathological process and are correlated to its typical electrophysiological subtype, affecting the SSP frequency.

Resumo Antecedentes A síndrome de Guillain-Barré (GBS) é a causa mais comum de paralisia flácida aguda em todo o mundo e pode ser classificada em subtipos eletrofisiológicos e variantes clínicas. Objetivo Este estudo teve como objetivo comparar a frequência do padrão de preservação do sural (SSP) em subtipos e variantes de GBS. Métodos É um estudo de coorte retrospectivo que analisou dados clínicos e eletrofisiológicos de 171 pacientes com GBS internados em hospitais públicos e privados de Natal, Rio Grande do Norte, Brasil, entre 1994 e 2018. Todos os casos foram acompanhados pelo mesmo neurologista em centro de referência em neurologia. Os pacientes foram classificados de acordo com os subtipos eletrofisiológicos e variantes clínicas e a frequência do SSP foi comparada em ambas as categorias. O teste exato de Fisher e a correção de Bonferroni foram utilizados para análise estatística. Resultados O SSP esteve presente em 53% (57 de 107) dos pacientes com polirradiculoneuropatia desmielinizante inflamatória aguda (PDIA), em 8% (4 de 48) dos pacientes com subtipos axonais e em 31% (5 de 16) dos casos não definidos. A frequência do SSP no AIDP foi significativamente maior do que nos subtipos axonais (p < 0,0001); o valor manteve-se elevado após exames eletrofisiológicos seriados. Apenas o subtipo paraparético não apresentou SSP. Conclusão O SSP pode estar presente na PDIA e nos subtipos axonais, incluindo a neuropatia axonal motora aguda, mas está significativamente mais presente na PDIA. Além disso, as variantes clínicas refletem um processo patológico específico e estão correlacionadas ao seu subtipo eletrofisiológico típico, afetando a frequência do SSP.

Vascularized Sural Nerve Graft, Fascial Free Flap, and Regenerative Peripheral Nerve Interface in the Setting of Recurrent Thigh Liposarcoma: A Case Report.

Background: There is no clear consensus in the literature regarding clinical indications for vascularized nerve grafts. Most studies indicate that vascularized nerve grafting, rather than non-vascularized nerve grafting, is indicated for nerve gaps of greater than 7 cm. Vascularized nerve grafts are superior to non-vascularized nerve grafts because they possess an independent blood supply. However, not all nerve injuries can be repaired via vascularized nerve grafts. Methods: A 32-year-old female received a fascial free flap and vascularized sural nerve graft after having multiple reresections of a recurrent thigh liposarcoma. Results: A 25-cm segment of the sural nerve was isolated alongside the lesser saphenous vein and intervening fascia. The free fascial flap was subsequently reversed and placed into the thigh. Vascular anastomoses were created, and the sural nerve was anastomosed to the peroneal nerve. A small portion of muscle from the thigh was wrapped around tibial nerve fascicles of the sciatic nerve to create a regenerative nerve interface. Conclusions: Benefits of vascularized sural nerve graft compared with other vascularized nerve grafts include negligible sensory loss at the donor site and a nerve graft that can be designed on itself due to its vast length. Additionally, vascularized sural nerve grafts provided a better rate of axonal regeneration, rate of electromyographic return, and motor and sensory outcome compared with non-vascularized sural nerve grafts.

Diagnostic Approach to Lower Limb Entrapment Neuropathies: A Narrative Literature Review.

Entrapment neuropathies of the lower limb are a misunderstood and underdiagnosed group of disorders, characterized by pain and dysesthesia, muscular weakness, and specific provoking movements on physical examination. The most frequent of these syndromes encountered in clinical practice are fibular nerve entrapment, proximal tibial neuropathy, sural nerve neuropathy, deep gluteal syndrome or sciatic nerve entrapment, and lateral femoral cutaneous nerve entrapment, also known as meralgia paresthetica. These are commonly mistaken for lumbar plexopathies, radiculopathies, and musculotendinous diseases, which appear even more frequently and have overlapping clinical presentations. A comprehensive anamnesis, physical examination, and electrodiagnostic studies should help clarify the diagnosis. If the diagnosis is still unclear or a secondary cause of entrapment is suspected, magnetic resonance neurography, MRI, or ultrasonography should be conducted to clarify the etiology, rule out other diseases, and confirm the diagnosis. The aim of this narrative review was to help clinicians gain familiarity with this disease, with an increase in diagnostic confidence, leading to early diagnosis of nerve damage and prevention of muscle atrophy. We reviewed the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and EDX technique and interpretation of the entrapment neuropathies of the lower limb, using articles published from 1970 to 2022 included in the Pubmed, MEDLINE, Cochrane Library, Google Scholar, EMBASE, Web of Science, and Scopus databases.