Major Nerve Research Articles

Revisiting the scorpion central nervous system using microCT

The central nervous system (CNS) of Chelicerata has remained conserved since the Cambrian, yet few studies have examined its variability within chelicerate orders including Scorpiones. The scorpion CNS comprises the prosomal ganglion and opisthosomal ventral nerve cord. We visualize the scorpion CNS with microCT, explore morphological variation across taxa, compare the scorpion CNS to other arachnids, and create a terminology glossary and literature review to assist future studies. Six scorpion species were microCT scanned. Scan quality varied and most structures in the prosomal ganglion could only be observed in Paruroctonus becki (Vaejovidae). Major nerves and the first opisthosomal ganglion were visible in nearly all taxa. We present the most detailed 3D-rendering of the scorpion prosomal ganglion to date. Our results corroborate existing research and find the scorpion CNS to be conserved. Nearly all structures reported previously in the prosomal ganglion were located in similar positions in P. becki, and nerve morphology was conserved across examined families. Despite similarities, we report differences from the literature, observe taxonomic variation in prosomal ganglion shape, and confirm positional variation for the first opisthosomal ganglion. This study serves as a starting point for microCT analysis of the scorpion CNS, and future work should include more distantly related, size variable taxa to better elucidate these findings.

Comprehensive Review of Inner Ear Anatomy on Photon-Counting CT.

The inner ear contains many fissures and canals that can mimic pathology. Photon-counting CT allows greater spatial and contrast resolution of these structures over traditional energy-integrating CT detectors. Small channels containing nerves, arteries, and normal anatomy such as the cochlear cleft and cochlear and vestibular aqueducts are commonly encountered on temporal bone imaging. The improved visualization of these structures poses challenges for radiologists who are new to photon-counting CT. This article updates the existing temporal bone anatomy literature with a detailed anatomic review of the inner ear and major nerves frequently encountered when reviewing temporal bone imaging.

Whole-body MRI-based long-term evaluation of pediatric NF1 patients without initial tumor burden with evidence of newly developed peripheral nerve sheath tumors

BackgroundPatients with neurofibromatosis type 1 (NF1) can develop plexiform neurofibromas (PN). Large tumor burden is a predictor for the development of malignant peripheral nerve sheath tumors. Whole-body magnetic resonance imaging (WB-MRI) is the recommended imaging method for the evaluation of PN. WB-MRI is recommended for NF1 patients at transition from adolescence to adulthood. In the absence of internal PN further follow-up WB-MRI is not considered necessary. PN are often detected in early childhood, leading to the assumption that they may be congenital lesions. It remains unclear whether this invariably applies to all patients or whether patients who initially displayed no tumors can still develop PN over time. Therefore, we retrospectively reviewed WB-MRI scans of pediatric patients with NF1 without initial tumor burden and compared these with long-term follow-up scans for presence of newly developed PN.MethodsWe retrospectively reviewed WB-MRI scans of 17 NF1-children (twelve male; median age at initial scan: 9 [IQR 6.1–11.9] years) who initially displayed no PN. MRI scans with a follow-up interval of at least 6 years (median follow-up interval: 9 [IQR 5.6–12.4] years) were reviewed in consensus by two radiologists regarding the development of new PN over time.ResultsNew PN were identified in two out of 17 children without initial tumor burden in follow-up examinations. One of these two patients developed two larger distinct PN of 4.5 cm on the right upper arm and of 2.5 cm on the left thoracic wall between the age of ten and twelve. The second child developed multiple smaller PN along the major peripheral nerves between the age of eleven and 16. In addition, 15 of the children without initial tumor burden did not develop any distinct tumors for a period of at least 6 years.ConclusionOur results indicate that PN can be newly detected in pediatric patients over time, even if no PN were detected on initial MRI scans. Therefore, it seems reasonable to perform at least a second MRI in pediatric NF1 patients at transition to adulthood, even if they did not display any tumor burden on initial MRI, and when the MRI was performed significantly under the age of 18. With this approach, tumors that may have developed between scans can be detected and patients at risk for complications can be identified.

Full-Incision Double-Eyelid Blepharoplasty with Selective Sensory Nerve Preservation.

Full-incision double-eyelid blepharoplasty can result in upper eyelid skin numbness postoperatively. However, few studies have examined sensory loss after eyelid surgery. We propose a novel surgical approach with selective sensory nerve preservation to prevent postoperative upper eyelid numbness. We enrolled 90 patients who underwent full-incision double-eyelid blepharoplasty with selective sensory nerve preservation from March 2021 to February 2022. Major longitudinal nerves that spread vertically to the palpebral margin under the orbicularis oculi muscle in the medial portion of the upper eyelid were dissected and carefully preserved. Eyelid sensation was measured using a Cochet-Bonnet filament-type esthesiometer at four predetermined anatomical locations in the upper eyelid. The mean esthesiometry reading was calculated at the preoperative and 2-week and final postoperative visits. The follow-up duration was 2-4 months (mean, 3 months). The mean esthesiometry readings at the inferonasal location were 5.22 cm (n=170, SD=0.28) preoperatively, 5.21 cm (n=170, SD=0.31) at 2 weeks postoperatively, and 5.22 cm (n=170, SD=0.29) at the final postoperative visits. Sensation was not significantly different between the second visit and the baseline (P=0.014) or between the final visit and the baseline (P=0.158). None of the patients reported a reduction in their subjective eyelid sensation. Full-incision double-eyelid blepharoplasty with selective sensory nerve preservation can prevent postoperative upper eyelid numbness while producing reliable and dynamic palpebral creases. The vital nerve branches of the upper eyelid can be preserved, thereby retaining skin sensation near the margin of the eyelid. We propose a novel full-incision double-eyelid blepharoplasty technique that incorporates selective sensory nerve preservation to prevent postoperative upper eyelid numbness. Full-incision double-eyelid blepharoplasty with selective sensory nerve preservation can prevent postoperative upper eyelid numbness while producing reliable and dynamic palpebral creases. The vital nerve branches of the upper eyelid can be preserved, thereby retaining skin sensation near the margin of the eyelid. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Repeating ultrastructural motifs provide insight into the organization of the octopus arm nervous system

The peripheral nervous system of the octopus is among the most complex of any animal. In each arm, hundreds of serial ganglia form a central core of nervous tissue processing sensory input, issuing motor commands, and exchanging information with the central brain.1,2,3,4,5 In addition to the central cord, there are two other types of neural elements: fine intramuscular nerve cords (INCs)6,7 and small sucker ganglia at the base of each sucker.2,6,8,9 Connections between these different elements and the structural organization of the arm nervous system remain poorly understood, despite decades of interest and a more recent explosion of studies of the cephalopod nervous system.8,10,11,12,13,14,15 Here, we use serial blockface electron microscopy to reconstruct large volumes of an arm from Octopus bocki at the base and toward the tip, mapping connections between the various neural elements and their relationship to the muscle and skin. We show that the ganglia follow an alternating mirror-image pattern along the arm, where the left or right-sided location of successive suckers determines ganglionic orientation. We also describe previously unrecognized patterns in (1) continuity of oblique connectives between the INCs that encircle the arm; (2) repeatable structures of the major blood vessel branches and nerve connectives within each ganglion; (3) clustering of rare, unusually large neurons within the cell body layers; and (4) division of the cortex into repeating columns. These new findings from the first 3DEM reconstruction of the arm should greatly facilitate future studies of octopus neurobiology, particularly sensori-motor integration and arm control.

The 'vulnerable nerve'; surgically acquired neuropathy in distal humeral surgery patients and the role of a tourniquet.

The complication of neuropathy is high in patients undergoing distal humerus surgery. Tourniquets (TQs) are typically used but can lead to nerve injury. We present a comparative study of a pre-intervention group (n = 38) and a post-intervention group (n = 38) undergoing distal humerus surgery between November 2020 and July 2023. The intervention included TQ discontinuation and the introduction of intravenous tranexamic acid at induction. Our analysis encompasses patient, anaesthetic, and surgical variables, as well as the rates and severity of neuropathy. Post-intervention, the rate of surgically acquired or deterioration in nerve injury improved from 15.8% (n = 6) to 2.6% (n = 1). Pre-intervention, the mean TQ duration was significantly longer for patients with post-operative neuropathy versus those without (120 min, SD = 29 vs. 88 min, SD = 38, p = 0.032). Surgery duration was not significantly longer without a TQ but was associated with a greater reduction in haemoglobin (12.7 g/L, SD = 10.9 vs. 25.2 g/L, SD = 15.5, p = 0.03). Trauma patients have a high risk of acquiring a nerve injury following elbow surgery or deterioration of a pre-surgical nerve injury, which emphasises the concept of vulnerable nerves. The cessation of using a TQ was associated with a lower nerve injury rate, with no cases of major nerve injury and no significant increase in surgical time.

Cost Analysis of Pelvic Exenteration Surgery for Advanced Pelvic Malignancy

BackgroundPelvic exenteration (PE) is a radical procedure involving multi-visceral resection for locally advanced pelvic malignancies. Such radical surgery is associated with prolonged operating theater time and hospital stay, as well as a substantial risk of postoperative complications, and therefore significant financial cost. This study aimed to comprehensively detail the inpatient cost of PE at a specialist center in the Australian public sector.MethodsA retrospective costing review of consecutive PE operations at Royal Prince Alfred Hospital in Sydney between March 2014 and June 2022 was performed. Clinical data were extracted from a prospectively maintained database, and in-hospital costing data were provided by the hospital Performance Unit. All statistical analyses were performed using SPSS.ResultsPelvic exenteration was performed for 461 patients, of whom 283 (61 %) had primary or recurrent rectal cancer, 160 (35 %) had primary or recurrent non-rectal cancer, and 18 (4 %) had a benign indication. The median admission cost was $108,259.4 ($86,620.8–$144,429.3) (Australian dollars [AUD]), with the highest costs for staffing followed by the operating room. Overall, admission costs were higher for complete PE (p < 0.001), PE combined with cytoreductive surgery (CRS) (p < 0.001), and older patients (p = 0.006).DiscussionThe total admission cost for patients undergoing PE reflects the complexity of the procedure and the multidisciplinary requirement. Patients of advanced age undergoing complete PE and PE combined with CRS incurred greater costs, but the requirement of a sacrectomy, vertical rectus abdominal flap reconstruction, major nerve or vascular excision, or repair were not associated with higher overall cost in the multivariate analysis.

Managing Major Peripheral Nerves in Forearm-Level Amputations With TMR and RPNI: What's the Best Recipe?

Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) prevent symptomatic neuroma formation in amputees. Forearm-level amputations present multiple muscular targets, making it challenging to determine the ideal treatment. The purpose of this study was to evaluate the best TMR targets, role of RPNI, and appropriate patient-selection criteria in forearm-level amputations. We hypothesized that deep and distal TMR targets would best prevent symptomatic neuromas, RPNI would prove a success adjunct, and patients with poorly controlled diabetes would not develop symptomatic neuromas regardless of nerve management. We retrospectively identified forearm-level amputations performed between 2017 and 2022. Patients with TMR by outside providers, follow-up <6 months, or insufficient documentation were excluded. Demographics, surgical nerve management, and postoperative complications were collected. The primary outcome was development of a painful neuroma determined by the Eberlin criteria. Patients undergoing TMR were divided a priori into two groups, superficial and proximal versus deep and distal TMR targets, and were compared. Thirty-nine patients met inclusion criteria, and 16 developed a symptomatic neuroma. No patients with a deep or distal TMR target developed a symptomatic neuroma. One nerve out of 12 treated with RPNI developed a symptomatic neuroma. No patient with poorly controlled diabetes developed a symptomatic neuroma, despite no advanced nerve management. In a case series of forearm amputations, deep and distal TMR targets prevented symptomatic neuroma formation more than superficial and proximal targets. Regenerative peripheral nerve interface is a useful adjunct for neuroma control, especially for the radial sensory nerve. Patients with poorly controlled diabetes may not require advanced nerve management. Level IV retrospective case series.

Intratumoral Microbiome in Head and Neck Paragangliomas.

Head and neck paragangliomas (HNPGLs) are rare neoplasms arising from paraganglia of the parasympathetic nervous system. HNPGLs are characterized by high vascularity and are located in proximity to major vessels and nerves, which may be potential sources of microbial invasion in these tumors. There have been no studies in the literature on the microbiota in HNPGLs. Investigation of the microbiome associated with paragangliomas is important for understanding tumor pathogenesis. In this study, we investigated the microbiome composition in two sets of HNPGLs. First, 29 fresh frozen (FF) tissues were subjected to 16S rRNA gene sequencing; concurrently, a panel of candidate laboratory-derived contaminants was investigated. Second, we analyzed microbial reads from whole transcriptome sequencing data obtained for 82 formalin-fixed paraffin-embedded (FFPE) HNPGLs. The bacterial diversity in FF tumors was found to be significantly lower than that observed in FFPE HNPGLs. Based on 16S rRNA gene sequencing, only seven bacterial families were identified as potential tumor inhabitants: Bryobacteraceae, Enterococcaceae, Neisseriaceae, Legionellaceae, Vibrionaceae, Obscuribacteraceae, and Mycobacteriaceae. However, RNA-Seq demonstrated higher sensitivity for identifying microbiome composition and revealed abundant bacterial families that partially correlated with those previously described in pheochromocytomas and extra-adrenal paragangliomas. No viruses were found in HNPGLs. In summary, our findings indicated the presence of a microbiome in HNPGLs, comprising a number of bacterial families that overlap with those observed in pheochromocytomas/paragangliomas and glioblastomas.

Ultrasound Image-guided Injection to Temporomandibular Joint

Ultrasonography is the newest imaging modality used for the diagnosis and interventional procedures of oral and maxillofacial region in dentistry now. Although it is not the first and foremost imaging modality in the diagnosis of temporomandibular disorders, it can be the complementary and alternative one for arthrography, CBCT, CT, and MRI. Ultrasonography of temporomandibular joint (TMJ) does not show the anatomical structures easy to understand like CT or MRI, but it gives some useful diagnostic information on internal derangement, capsulitis, and degenerative joint disease of TMJ. Ultrasound image-guided injection to TMJ can improve the accuracy and efficacy, and can minimize the potential damage to adjacent tissues including major vessles and nerves.

Gender-Specific Variations in Greater Palatine Foramen Anatomy: Insights from CBCT Scans in the North Cyprus Population.

BACKGROUND The greater palatine foramen (GPF) is anatomically located distal to the third maxillary molar tooth, midway between the midline of the palate and the dental arch. The GPF contains the major palatine artery, vein, and nerve, traversing the palatine sulcus. This study aimed to evaluate the anatomical position of the GPF in 93 women and 67 men at a single center in Cyprus using cone beam computed tomography (CBCT). MATERIAL AND METHODS A retrospective analysis was conducted on 160 CBCT scans. Measurements of the GPF's horizontal and vertical diameters, distances from GPF to the incisive foramen, posterior nasal spine, anterior nasal spine, and midaxillary suture, and positional relationships to molars were recorded. Statistical analyses compared these measurements between males and females. RESULTS The study included 93 females and 67 males with an average age of 46.6 (±11.6) years. Significant sex differences were observed in most GPF measurements, with males showing larger dimensions such as the anterior nasal spine, posterior nasal spine, mid-maxillary suture, and incisive foramen to the GPF. The GPF was predominantly located in the third molar region (96.25% on the right, 96.9% on the left). The left GPF showed a significantly larger horizontal diameter than the right (P<0.05). CONCLUSIONS There was a significant difference in the average distances from the anterior nasal spine, posterior nasal spine, mid-maxillary suture, and incisive foramen to the GPF, as well as in the size of the GPF, between males and females. Recognizing these variations enhances clinical planning and reduces the risk of complications.

CT and MR Imaging Findings of Lingual Nerve Perineural Spread

Retrograde perineural spread is a well-described entity involving many major nerves, including the inferior alveolar, facial, and branches of the trigeminal nerves. However, isolated perineural spread along the lingual nerve has not been well-described in the literature and is often overlooked. Lingual nerve perineural spread is a potential pathway of recurrent floor of the mouth cancers, which are often clinically occult. This article describes the CT and MR imaging findings of lingual nerve perineural spread characterized by thickening and enhancement along the course of the lingual nerve, which extends from the lateral floor of the mouth (between the mylohyoid and hyoglossus muscles), proximally along the medial aspect of the mandibular ramus to the main trunk of mandibular nerve. We also identify 5 unique anatomic “anchor points” that represent imaging landmarks that help radiologists diagnose patients with potential lingual nerve involvement and assist radiation oncologists in contouring the lingual nerve pathway and planning initial treatment in patients with high risk of perineural spread.Learning Objective: To describe the CT and MR imaging findings of lingual nerve perineural spread and provide imaging landmarks that help the neuroradiologist identify lingual nerve involvement and assist radiation oncologists in planning the initial treatment in patients with a high risk of lingual nerve perineural spread

Frequency and Localization of Neuromas in Transtibial Residual Limbs

ObjectiveTo describe the frequency and localization of neuromas in residual limbs of individuals with transtibial amputation using ultrasound imaging. DesignCross-sectional study. SettingRehabilitation center research laboratory. ParticipantsAdults who have lived with a transtibial amputation for >12 months were recruited for this study. Participants were included regardless of the presence or absence of residual limb neuropathic pain. Twenty-three participants (24 transtibial residual limbs) with and without residual limb neuropathic pain were enrolled. The etiology of amputation of most participants was peripheral vascular disease and diabetes. InterventionA comprehensive history was collected and a musculoskeletal ultrasound assessment for the presence and location of neuromas in their residual limb was conducted. During the ultrasound evaluation, a sonopalpation Tinel test was performed by applying pressure on each neuroma with the probe. Main Outcome MeasuresNumber of neuromas and their localization in each residual limb examined. ResultsA total of 31 neuromas in the 24 transtibial residual limbs were identified by ultrasound imaging. The average number of neuromas per residual limb was 1.3. All the major peripheral nerves studied could present neuromas, with a predominance of the superficial fibular nerve within our sample. Thirty-five percent of all the neuromas were described as painful. ConclusionsThe presence of terminal neuromas on surgically sectioned nerves in transtibial residual limbs is frequent. Seventy-nine percent of participants had at least one neuroma. Ultrasound imaging is clinically useful to identify neuromas. The evaluator can easily communicate with the patient to diagnose symptomatic neuromas.

Developmental Anatomy of Gray Matter of Spinal Cord in Animals with Special Reference to Prenatal Goat: A Review

Spinal cord is the major nerve tract of vertebrates, extending from the brain through the vertebral canal. Primordium, the neural tube was initially with thick lateral walls having three layers: inner germinal/ependymal layer, middle mantle layer forming the gray matter and outer marginal layer forming white matter. It presented a diamond-shaped lumen with a sulcus limitans, alar, basal, roof and floor plates and limiting membranes. Gray matter of the cord occupies the central region of spinal cord and in amniotes has in cross section, the well-known ‘H’ or butterfly-like shape. The white matter forms a thick peripheral zone of the cord and is divided by the gray columns into dorsal, lateral and ventral funiculi. There are three coumns for the gray matter, viz. the dorsal, ventral and lateral horns, with ventral ones being wider at the enlargements of the cord. Lateral horn appears only at thoracic, anterior lumbar and middle sacral levels. The layers of gray matter were laminae I to X. Lamina I or marginal zone capped the dorsal horn. Lamina II represented substantia gelatinosa and covered the dorsal horn, beneath marginal zone. Lamina III was an area with loosely arranged larger cells, entering the substantia gelatinosa. Lamina IV was a poorly defined cell column with nucleus proprius. Lamina V was a broad zone extending across the cervix of the dorsal horn; had spinal reticular nucleus and reticular processes. The region showed small to medium-sized cells which were most numerous in the zone between the ventral part of the dorsal horn and the lateral funiculus of white matter. Lamina VI was broad with unclear boundaries, related medially to central canal. It had compact medial and less compact lateral zones. Lamina VII shows the intermediate gray matter, with intermediolateral and intermediomedial nuclei, cervical nucleus of Stilling and Clark’s column. Lamina VIII had cells of small and medium size and was not sharply distinguished from lamina VII. Lamina IX had alpha and gamma type of neurons, which were larger at enlargements. Ventral horn had lateral and medial nuclear groups of multipolar neurons. Medial nuclear groups were seen in all regions and lateral groups only at enlargements. Medial nuclear group had dorsomedial and ventromedial nuclei; whereas the smaller lateral nuclear group had dorsolateral and ventrolateral nuclei. In addition, the enlargements also had central and retrodorsolateral nuclei. Lamina X was seen around the central canal. Laminae varied in cell size and thickness between regions of the cord. Development of laminae and nuclei of spinal gray in fetuses corresponded to the progressive growth of muscles and skeleton. All the ten laminae were together present in the spinal gray matter by the end of gestation.

Wet Field Bi-Polar Surgical Treatment for Retinopathy

Retinopathy is a major cause due to high blood sugar and it affects the major nerves damage in the back of our eyes. This poor management of sugar levels in our daily intakes and it initiates major cause in human vision. Diabetic retinopathy rectification has most important favored for the every patient whose are affected by the diabetic mellitus. Surgery and surgical instrument based retinopathy has a most featured approach. Wet-field bi- polar cautery is an instrument to reduce the unwanted progressive tissue in our eyes. This device or temperature generated has controlled with the aid of sensor and microcontroller devices. This sensor based temperature optimization has increased the performance of the device. The current scenarios of the device and temperature level have explicated via various electronic devices and improve the surgical performance. Thus the efficiency and effectiveness of the system has most useful for the diabetic retinopathy patients.

Trends in the Prevalence of Common Retinal and Optic Nerve Diseases in China: An Artificial Intelligence Based National Screening.

Retinal and optic nerve diseases have become the primary cause of irreversible vision loss and blindness. However, there is still a lack of thorough evaluation regarding their prevalence in China. This artificial intelligence-based national screening study applied a previously developed deep learning algorithm, named the Retinal Artificial Intelligence Diagnosis System (RAIDS). De-identified personal medical records from January 2019 to December 2021 were extracted from 65 examination centers in 19 provinces of China. Crude prevalence and age-sex-adjusted prevalence were calculated by mapping to the standard population in the seventh national census. In 2021, adjusted referral possible glaucoma (63.29, 95% confidence interval [CI] = 57.12-68.90 cases per 1000), epiretinal macular membrane (21.84, 95% CI = 15.64-29.22), age-related macular degeneration (13.93, 95% CI = 11.09-17.17), and diabetic retinopathy (11.33, 95% CI = 8.89-13.77) ranked the highest among 10 diseases. Female participants had significantly higher adjusted prevalence of pathologic myopia, yet a lower adjusted prevalence of diabetic retinopathy, referral possible glaucoma, and hypertensive retinopathy than male participants. From 2019 to 2021, the adjusted prevalence of retinal vein occlusion (0.99, 95% CI = 0.73-1.26 to 1.88, 95% CI = 1.42-2.44), macular hole (0.59, 95% CI = 0.41-0.82 to 1.12, 95% CI = 0.76-1.51), and hypertensive retinopathy (0.53, 95% CI = 0.40-0.67 to 0.77, 95% CI = 0.60-0.95) significantly increased. The prevalence of diabetic retinopathy in participants under 50 years old significant increased. Retinal and optic nerve diseases are an important public health concern in China. Further well-conceived epidemiological studies are required to validate the observed increased prevalence of diabetic retinopathy, hypertensive retinopathy, retinal vein occlusion, and macular hole nationwide. This artificial intelligence system can be a potential tool to monitor the prevalence of major retinal and optic nerve diseases over a wide geographic area.

Phantom limb pain, traumatic neuroma, or nerve sheath tumor? Illustrative case.

Phantom limb pain and traumatic neuromas are not commonly seen in neurosurgical practice. These conditions can present with similar symptoms; however, management of traumatic neuroma is often surgical, whereas phantom limb pain is treated with conservative measures. A 77-year-old female patient with a long-standing history of an above-the-knee amputation experienced severe pain in her right posterior buttocks area for several years' duration, attributed to phantom limb pain, which radiated down the stump of her leg and was treated with a variety of conservative measures. A recent exacerbation of her pain led to a prolonged hospitalization with magnetic resonance imaging of her leg stump, revealing a mass in the sciatic notch, at a relative distance from the stump. The anatomical location of the mass on the sciatic nerve in the notch led to a presumed radiological diagnosis of nerve sheath tumor, for which she underwent excision. At surgery, a neuroma of the proximal portion of the transected sciatic nerve that had retracted from the amputated stump to the notch was diagnosed. Traumatic neuromas of transected major nerves after limb amputation should be considered in the differential diagnosis of phantom limb pain.

Updates in diagnostic tools for diagnosing nerve injury and compressions.

Predicting prognosis after nerve injury and compression can be challenging, even for the experienced clinician. Although thorough clinical assessment can aid diagnosis, we cannot always be precise about long-term functional recovery of either motor or sensory nerves. To evaluate the severity of nerve injury, surgical exploration remains the gold standard, particularly after iatrogenic injury and major nerve injury from trauma, such as brachial plexus injury. Recently, advances in imaging techniques (ultrasound, magnetic resonance imaging [MRI] and MR neurography) along with multimodality assessment, including electrodiagnostic testing, have allowed us to have a better preoperative understanding of nerve continuity and prediction of nerve health and possible recovery. This article outlines the current and potential roles for clinical assessment, exploratory surgery, electrodiagnostic testing ultrasound and MRI in entrapment neuropathies, inflammatory neuritis and trauma. Emphasis is placed on those modalities that are improving in diagnostic accuracy of nerve assessment before any surgical intervention.

Socioeconomic factors and outcome after repair and reconstruction of digital and major nerve trunk injuries in the upper limb

Peripheral nerve injuries in the upper limb can lead to substantial disability and pain. We aimed to assess how socioeconomic factors affect outcomes after repaired or reconstructed digital or major nerve trunk injuries in the upper limb. We identified 670 individuals, who underwent surgical nerve repair or reconstruction using sensory nerve autografts, in the Swedish National Quality Registry for Hand Surgery 2010–2018. Socioeconomic factors, including education, cohabitation, type of work, sick leave, immigrant status and income, were gathered from the Swedish statistical agency (www.scb.se) and National Diabetes Register (NDR). We calculated prevalence ratios (PR) to assess the relationship between socioeconomic factors and surgical outcomes for the nerve injuries. Individuals with a major nerve trunk injury had higher QuickDASH scores and lower income compared to those with digital nerve injury. Individuals with immigration background (adjusted PR = 2.0, 95% CI 1.2–3.2), history of > 4 weeks of sick leave the year before surgery (adjusted PR = 1.8, 95% CI 1.1–3.1), or education level below tertiary (adjusted PR = 2.8, 95% CI 1.7–4.7) had significantly higher QuickDASH scores. Recognizing impact of non-biological factors, including immigration, prior sick leave, and education level, on outcome after nerve surgery is crucial for improving prognosis in socioeconomically deprived individuals.

The 2-by-2 Inch “Key Window” in the Upper Extremity: An Anatomical Appraisal of the Accessibility and Proximity of the Major Nerves and Vessels

The brachial plexus is a network of nerves located between the neck and axilla, which receives input from C5-T1. Distally, the nerves and blood vessels that supply the arm and forearm form a medial neurovascular bundle. The purpose of this study was to illustrate that a peripheral nerve dissection via a 2×2 inch window would allow for identification and isolation of the major nerves and blood vessels that supply the arm and forearm. A right side formalin-fixed latex-injected cadaveric arm was transected at the proximal part of the axillary fold and included the scapular attachments. Step-by-step anatomical dissection was carried out and documented with three-dimensional digital imaging. A 2×2 inch window centered 2 inches distal to the axillary fold on the medial surface of the arm enabled access to the major neurovascular structures of the arm and forearm: the median nerve, ulnar nerve, medial antebrachial cutaneous nerve, radial nerve and triceps motor branches, musculocutaneous nerve and its biceps and brachialis branches and lateral antebrachial cutaneous nerve, basilic vein and brachial artery and vein, and profunda brachii artery. Our study demonstrates that the majority of the neurovascular supply in the arm and forearm can be accessed through a 2×2 inch area in the medial arm. Although this "key window" may not be entirely utilized in the operative setting, our comprehensive didactic description of peripheral nerve dissection in the cadaver laboratory can help in safer identification of complex anatomy encountered during surgical procedures.