Major Nerve Research Articles

Abstract 111: Maternal Separation, a Model of Early Life Stress in Rats, Dysregulates the Renal Vasculature Gene Expression Patterns During Late Nephrogenic Period and Adult Life

We have shown that maternal separation (MatSep) induces permanent alterations in the renal vascular structure, hemodynamics and sympathetic outflow. Environmental stressors are typically associated with abnormal organ development. Recently, we found that MatSep pups show higher levels of plasma corticosterone and renal norepinephrine during postnatal life (p< 0.05). The aim of this study was to investigate the short and long-term effects of MatSep on gene expression patterns of the renal vasculature. MatSep was performed during early postnatal life timeframe (3hr/day). Undisturbed littermates served as control (C). Upon weaning, rats were allowed to grow and develop for several months. Kidney vessels were isolated at postnatal day 10 (PND10, n=5) and 6 months of age (6Mo, n=5) and flash frozen. mRNA was used to perform genome-wide analysis using Affymetrix rat Gene2.0 ST. EBPfc* analysis was conducted using DAVID bioinformatics resources at NIH website. MatSep altered 1108 genes expression (P<0.03, FDR<0.3,Table 1). We found a set of genes upregulated by MatSep at both PND10 and 6Mo, showing long-lasting changes in expression. The uncoupling protein 1 (UCP1), located proximal to the major vascular and nerve conduits to the kidney, was the highest MatSep-induced upregulation (3.9-fold, PND10). UCP1 network of genes were mostly related to cellular organization and metabolic and cardiovascular disease (e.g. GH, AT1R, AT2R, P38 MAPK, IFNγR, VEGF, ApoE). Thus, MatSep influences timing and direction of key genes involved in the renal vascular maturation. Upregulated non-shivering thermogenesis function early in life may be linked to impaired renal function. NIH R00 HL111354

Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths

During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure.

Development and validation of a new method for locating patella sensory nerves for the treatment of inferior and superior knee pain.

BackgroundRadiofrequency ablation and percutaneous cryoneurolysis to relieve knee pain requires treating large areas to ensure coverage due to high variability in the sensory innervation of the knee and limitations of current methods for defining treatment targets. This study sought to define and validate a new treatment approach targeting the major sensory nerves of the superior patella and expand upon previous work to define a more efficient treatment approach targeting the sensory nerves of the inferior patella.MethodsTranscutaneous electrical nerve stimulation and ultrasound were used to evaluate the location and relationship of the cutaneous nerves to the superior and inferior aspects of the knee in 25 healthy volunteers. Using information derived from these evaluations, investigators defined new linear target treatment areas, or treatment lines, using anatomical landmarks, which were validated against locations of sensory nerves through cadaveric dissection of 15 fresh specimens.ResultsThe proposed treatment lines captured the vast majority of nerve branching variations during cadaveric validation.ConclusionThis study defined treatment lines, identifiable using only anatomical landmarks, which effectively target the nerves responsible for superior and inferior knee pain and reduce the total treatment area and procedure time when administering treatments such as radiofrequency ablation and cryoneurolysis.

Safe Zone for Neural Structures in Medial Displacement Calcaneal Osteotomy: A Cadaveric and Radiographic Investigation.

We aimed to define reference lines on standard lateral ankle radiographs that could be used intraoperatively to minimize iatrogenic nerve injury risk in medial displacement calcaneal osteotomy. Forty cadaveric specimens were used. In 20 specimens, the sural, medial plantar (MP), and lateral plantar (LP) nerves were sutured to radiopaque wire, and a lateral ankle radiograph was obtained. On the radiograph, a line was drawn from the posterior superior apex of the calcaneal tuberosity to the origin of the plantar fascia and labeled as the "landmark line." A parallel line was drawn 2 mm posterior to the most posterior nerve, and the area between these lines was defined as the safe zone. In 20 additional specimens, an osteotomy was performed 1 cm anterior to the landmark line using a percutaneous or open technique. Dissection was performed to assess for laceration of the sural, MP, LP, medial calcaneal (MC), or lateral calcaneal (LC) nerves. The safe zone was determined to be within the area 11.2 ± 2.7 mm anterior to the landmark line. After open osteotomy, lacerations were found in 3 of 10 MC nerves and 3 of 10 LC nerves. After percutaneous osteotomy, lacerations were found in 2 of 10 MC nerves and 1 of 10 LC nerves. No lacerations of the sural, MP, or LP nerves were found with either osteotomy. The safe zone extended 11.2 ± 2.7 mm anterior to the described landmark line. The MC and LC nerves were always at risk during medial displacement calcaneal osteotomy. Nerve injury to both major and minor sensory nerves is likely underrecognized as a source of morbidity after calcaneal osteotomy. The current study provides a ready intraoperative guideline for minimizing this risk.

Anatomical Study of the Ulnar Nerve Variations at High Humeral Level and Their Possible Clinical and Diagnostic Implications.

Background. Descriptive evaluation of nerve variations plays a pivotal role in the usefulness of clinical or surgical practice, as an anatomical variation often sets a risk of nerve palsy syndrome. Ulnar nerve (UN) is one amongst the major nerves involved in neuropathy. In the present anatomical study, variations related to ulnar nerve have been identified and its potential clinical implications discussed. Materials and Method. We examined 50 upper limb dissected specimens for possible ulnar nerve variations. Careful observation for any aberrant formation and/or communication in relation to UN has been carried out. Results. Four out of 50 limbs (8%) presented with variations related to ulnar nerve. Amongst them, in two cases abnormal communication with neighboring nerve was identified and variation in the formation of UN was noted in remaining two limbs. Conclusion. An unusual relation of UN with its neighboring nerves, thus muscles, and its aberrant formation might jeopardize the normal sensori-motor behavior. Knowledge about anatomical variations of the UN is therefore important for the clinicians in understanding the severity of ulnar nerve neuropathy related complications.

Electrophysiologic analysis of injury to cranial nerve XI during neck dissection.

Despite preservation of the accessory nerve, a considerable number of patients report partial nerve damage after modified radical neck dissection (MRND) and selective neck dissection. Accessory nerve branches for the trapezius muscle were stimulated during neck dissection, and the M wave amplitude was measured during distinct surgical phases. The accessory nerve was mapped in 20 patients. The M wave recordings indicated that major nerve damage occurred during dissection at levels IIa and IIb in the most proximal segment of the nerve. The M waves evoked from this nerve segment decreased significantly during surgery (analysis of variance; p = .001). The most significant intraoperative injury to the accessory nerve during neck dissection occurs at anatomic nerve levels IIa and IIb. © 2015 Wiley Periodicals, Inc. Head Neck 38: E372-E376, 2016.

Detailed Anatomy of the Cranial Cervical Ganglion in the Dromedary Camel (Camelus dromedarius).

The detailed morphology and topography of the cranial cervical ganglion (CCG) with its surrounding structures were studied in 10 sides of five heads of adult one-humped camel to determine its general arrangement as well as its differences and similarities to other animals. The following detailed descriptions were obtained: (1) the bilateral CCG was constantly present caudal to cranial base at the rostroventral border of the occipital condyle over the caudolateral part of nasopharynx; (2) the CCG was always in close relations medially with the longus capitis muscle, rostrolaterally with the internal carotid artery, and caudally with the vagus nerve; and (3) the branches of the CCG were the internal carotid and external carotid nerves, jugular nerve, cervical interganglionic branch, laryngopharyngeal branch, carotid sinus branch and communicating branches to the vagus, and first spinal nerves. In conclusion, there was no variation regarding topography of dromedary CCG among the specimens, in spite of typical variations in number, and mainly in origin of nerve branches ramifying from the CCG. In comparative anatomy aspect, the close constant relations, and presence of major nerves (internal/external carotid and jugular nerves) of dromedary CCG exhibited a typical reported animal's pattern. However, the shape, structures lateral to the CCG, the origin and course pattern of external carotid and jugular nerves, the number of the major nerves branches, the communicating branches of the CCG to the spinal and cranial nerves, and the separation of most rostral parts of vagosympathetic trunk of dromedary were different from those of most reported animals.

Transorbital transnasal endoscopic combined approach to the anterior and middle skull base: a laboratory investigation.

Orbital approaches provide significant trajectory to the skull base and are used with differently designed pathways. The aim of this study is to investigate the feasibility of a combined transorbital and transnasal approach to the anterior and middle cranial fossa. Cadaveric dissection of five silicon-injected heads was used. A total of 10 bilateral transorbital approaches and 5 extended endonasal approaches were performed. Identification of surgical landmarks, main anatomical structures, feasibility of a combined approach and reconstruction of the superior orbital defect were examined. Rod lens endoscope (with 0° and 45° lenses) and endoscopic instruments were used to complete the dissection. The transorbital approach showed good versatility and provides the surgeon with a direct route to the anterior and middle cranial fossa. The transorbital avascular plane showed no conflict with major nerves or vessels. Large exposure area from crista galli to the third ventricle was demonstrated with significant control of different neurovascular structures. A combined transorbital transnasal approach provides considerable value in terms of extent of exposure and free hand movement of the two surgeons, and allows better visualisation and control of the ventral skull base, thus overcoming the current surgical limits of a single approach. Combination of these two minimally invasive approaches should reduce overall morbidity. Clinical trials are needed to evaluate the virtual applications of this approach.

Anatomical basis for the development of a thoracic duct cannulation model without thoracotomy in Large White pigs.

BackgroundTo collect lymph draining the lungs provides a useful strategy for tracing pulmonary microvascular fluid and protein biology. A methodology that allows for in vivo sampling of efferent pulmonary lymph in real-time in sheep by cannulating the thoracic duct without entering the thoracic cavity was previously established. To develop a similar thoracic duct cannulation model without thoracotomy in pigs, we investigated the anatomy of the left cervico-thoracic regions of 15 Large White (Yorkshire or Yorkshire-dominated) piglets (aged 4–7 weeks).ResultsThe thoracic duct, together with the left tracheal trunk, joined the cardiovascular system (the ampulla of the thoracic duct) at a site located craniomedial to the first rib on the left in 80 % (12/15) of the piglets.ConclusionsAs the location of the ampulla of the thoracic duct was consistent in most of the piglets, Large White piglets appear to be suitable for the development of a thoracic duct cannulation model without thoracotomy. The anatomical findings in this study will enable the development of further surgical procedures for cannulating the thoracic duct without thoracotomy, with minimal damage to local tissue, and without transecting any major blood vessels, nerves or muscle bellies. The establishment of a thoracic duct cannulation model for collecting in vivo, in situ efferent lymph, including pulmonary lymph, in pigs without entering the thoracic cavity would be invaluable for many immunological studies, studies on pulmonary immune responses in particular.

A huge neurofibroma of the lower back invading the spinal cavity.

A huge neurofibroma of the lower back invading the spinal cavity.

Neural anatomy, neuromonitoring and related complications in extreme lateral interbody fusion: video lecture

The lateral retroperitoneal transpsoas approach to the lumbar spine requires passage in close proximity to both superficial and deep neural structures [1, 2]. While the majority of nerves that are at risk for injury in the lateral approach are located on and within psoas major (e.g., femoral and genitofemoral nerves), the subcostal, lateral femoral cutaneous, ilioinguinal, and iliohypogastric nerves are all located outside of the psoas muscle and may be encountered prior to passage through the psoas muscle (superficial nerves). Given the less-invasive nature of the approach adjacent to these structures, a clear understanding of the relevant anatomy with respect to neural architecture, followed by close adherence to intraoperative neuromonitoring and surgical technique may reduce the risk of neurologic injury.

Malignant peripheral nerve sheath tumor (MPNST) – case report and review of literature

Malignant peripheral nerve sheath tumors (Mpnsts) are locally invasive soft tissue sarcomas. these tumors constitute up to 10% of all soft tissue sarcomas. they arise from minor or major peripheral nerve branches or sheath of peripheral nerve fibers. they occur with equal frequency in males and females. the majority of malignant peripheral nerve sheath tumors are observed in the extremities. Because of its rarity, this neoplasm is often misdiagnosed. it is characterized by an aggressive behavior and rapid growth. the incidence of malignant peripheral nerve sheath tumor is low with a lifetime risk of 0,001%. the author of this article presented a case of a 76-year-old caucasian woman who was admitted to the department of surgical oncology because of malignant peripheral nerve sheath tumor (Mpnst) which was located on the right side of inguinal and pubis. the progression of disease was very fast. the author performed a literature review on malignant peripheral nerve sheath tumor (Mpnst) diagnosis and treatment.

Improving the radial nerve neurodynamic test: An observation of tension of the radial, median and ulnar nerves during upper limb positioning

The radial nerve neurodynamic test (ULNT2b), used to implicate symptoms arising from the radial nerve, is proposed to selectively increase strain of the nerve without increasing strain of adjacent tissue, though this has not been established. This study aimed to determine the upper limb position that results in: (1) the greatest tension of the radial nerve and (2) the greatest difference in tension between the radial nerve and the other two major nerves of the upper limb: median and ulnar. Tension (N) of the radial, median and ulnar nerves was measured simultaneously using three buckle force transducers during seven upper limb positions in the axilla of ten embalmed whole body human cadavers (n = 20 limbs). Repeated measures analysis of variance (ANOVA) with Bonferroni post-hoc tests determined differences in tension between nerves and between limb positions. A Composite position consisting of ULNT2b (scapular depression, shoulder internal rotation, elbow extension, forearm pronation, wrist flexion) with the addition of shoulder abduction 40° and extension 25°, wrist ulnar deviation and thumb flexion demonstrated significantly greater tension of the radial nerve than any other tested position (mean tension 11.32N; 95% CI 10.25, 12.29, p < 0.01), including ULNT2b (2.20N; 1.84, 2.57; p < 0.01). Additionally, the Composite position demonstrated the greatest difference in tension between the radial and median (mean difference 4.88N; 95% CI 3.16, 6.61; p < 0.01) and radial and ulnar nerves (9.26N, 7.54, 10.99; p < 0.01). This position constitutes a biomechanically plausible test to detect neuropathic pain related to the radial nerve.

Peripheral nerve tumours: 30-year experience in the surgical treatment.

Peripheral nerve tumours are relatively rare type of soft tissue tumours. The aim of this work is to present our experience with surgical treatment of this type of lesions. Clinical material consists of 94 patients (56 females, 38 males), in whom 101 tumours deriving from peripheral nervous system were removed. The patients underwent surgical treatment between 1983 and 2012. Tumours occurred mainly in the upper extremity (72 tumours), less often in the lower extremity (25 tumours). Lesions developed in major peripheral nerves (51 tumours) and small nerve branches (50 tumours). The most common symptoms reported before surgery included presence of tumour mass (100 %), positive Hoffmann-Tinel sign (95.6 %) and paraesthesia (93.4 %). Less often sensory deficit (89.1 %) and pain (71.7 %) were observed. Motor deficit was the least common manifestation (41.3 %). Benign tumours prevailed in presented material (94 tumours). In 7 cases, malignant peripheral nerve sheath tumour (MPNST) was identified. As a result of surgical treatment in the group of tumours deriving from major peripheral nerves, in 87.8 % of the patients, pain relief was achieved; in 84 %, Hoffmann-Tinel sign was negative; and in 79 %, paraesthesia resolved. Sensory function improvement was observed in 51.2 % of the patients while motor function improved in 26.3 % of the patients. None of the patients experienced tumour relapse. In the group of tumours deriving from small nerve branches, 47 patients had no signs of tumour recurrence. One female patient diagnosed with MPNST suffered a relapse. Obtaining satisfactory results of peripheral nerve tumour treatment requires both careful differential diagnosis and well thought-out strategy at every stage of therapeutic management.

The chorda tympani degenerates during chronic otitis media: an electron microscopy study

Conclusion: Chorda tympani nerve specimens from ears with chronic inflammatory middle ear disease exhibit structural signs of degeneration. These correlate well with taste disturbance. Simultaneously, they exhibit signs of regeneration, which may explain the ability for taste recovery. Objectives: The chorda tympani, the major taste nerve, runs uncovered through the middle ear cavity. This situation exposes it to various forms of middle ear pathology. A difference has been noticed regarding taste symptoms pre- and postoperatively between inflammatory and non-inflammatory diseases. The present study aimed to investigate ultrastructural changes of chorda tympani in different forms of inflammatory middle ear disease, such as chronic suppurative otitis media and cholesteatoma, as compared with normal. Methods: Five chorda tympani specimens were collected from healthy middle ears of patients subjected to surgery for acoustic neuroma, to be used as normal controls, and five from middle ears with chronic otitis media or cholesteatoma, where the nerve could not be saved during the operation. Light and electron microscopy were performed. Results: For all five nerves from diseased ears, microscopy showed a higher percentage of axon and myelin sheath degeneration than in the normal controls. Furthermore, three of the five also exhibited sprouting.

Complex Regional Pain Syndrome and Spontaneous Pain Following Simple Incision With Immobilization: A Case Report

Complex regional pain syndrome (CRPS) is characterized by vasomotor and sudomotor changes. Its etiology generally includes trauma, fracture, stroke, and coronary disease. It is evaluated in two subtypes: CRPS type I (reflex sympathetic dystrophy), presenting with complex regional pain syndromes accompanied by spontaneous pain, hyperalgesia, allodynia, edema, autonomic anomalies, and trophic changes; regional pain occurring after minor injuries and fractures in the extremities; and coexisting vasomotor, sudomotor changes, and sensorial changes, and CRPS type II (coxalgia), including major peripheral nerve injuries, in addition to all of these symptoms (1, 2). Although the pathogenesis of CRPS is not exactly known, peripheral and central sensitization, which causes neurogenic inflammation, is held responsible. The most possible mechanism is considered to be increased sensitivity against catecholamine, depending on sympathetic denervation, in addition to increased numbers or sensitivity of peripheral axonal adrenoreceptors. Moreover, some mechanisms, such as the release of neuropeptides from primary nociceptive afferents and sympathetic efferents [substance P, calcitonin gene-related peptide (CGRP) and neuropeptide Y] and the development of neurogenic inflammation, are suggested. This results clinically in hyper algesia and central sensitization, in which allodynia develops (3, 4). CASE REPORT

Postoperative recurrence of desmoid tumors: clinical and pathological perspectives.

BackgroundThe clinical features and the pathological changes of desmoid tumors were studied to point out the key factors affecting the recurrence.MethodsThe clinical data and specimens of 56 patients who underwent desmoid tumor resection from 2003 to 2008 were reviewed. Possible clinical factors related to the postoperative recurrence were analyzed statistically. The specimens round the lesions were studied histopathologically.ResultsThe overall recurrence rate was 39.3%. The postoperative recurrence rate of the patients with negative surgical margins and no tumor invasion of the major vessels and nerves was low (P < 0.05). However, the desmoid tumors could destroy the cortical bone and invade the medullary cavity.ConclusionsDesmoid tumors were pathologically benign, which could extensively invade tissues around the lesions. The invasion of major vessels and nerves and quality of surgical margins are the key factors for the high postoperative recurrence rate.

Impalement injuries of the left thorax, abdomen and axilla by reinforced iron rods—a case report

A 29-year-old male labourer fell on iron rods at a construction site which pierced through his abdomen and thorax. One rod, 5 ft long, entered the left hypochondrium injuring the transverse colon, spleen and entering the thorax through the diaphragm going through the superior segment of the lower lobe of the left lung and further going through the upper lobe touching the lateral pericardial surface and coming out through the second intercostal space midclavicular line. Another rod, 3 ft long, pierced the left axilla, sparing the axillary vessels and major nerves. The rods were successfully removed along with superior segmentectomy and repair of upper lobe injuries. Abdominal injury required diaphragm repair, colon repair and splenectomy. The patient made an uneventful recovery without any sequelae.

Effect of Unipolar Acu-Stim on Muscle Re-Education Following Tendon Transfer - A Case Study

Background:&nbsp;Tendon transfer surgery is usually done to improve function, following damage to either major nerve trunks or peripheral nerves. Re-education of the muscle is of utmost importance to gain functional activity.To achieve this, along with re-education exercises, faradic stimulation is usually used. Unipolar Acu-Stim (UAS), is an innovative technique where an acupuncture needle is used to stimulate the transferred tendon with Surged Faradic Currents (SFC). The objective of the study is to identify if the application of SFC using UAS method, is effective to re-educate a transferred muscle. Case Description:&nbsp;The subject was a 24 year old male who had a loss of finger and thumb extension following Posterior Interosseous Nerve (PIN) palsy, for which Flexor Carpi Radialis (FCR) was transferred to Extensor Digitorum Communis (EDC) and Palmaris Longus (PL) was transferred to Extensor Pollicis Longus (EPL). Following removal of the POP, UAS with surged faradic current was applied for 4 weeks along with re-education exercises. Prognosis of finger extension was assessed by goniometry and video recordings. Outcome:&nbsp;At the end of 8th week, as observed on goniometry and video recordings, complete finger extension was achieved. Discussion:&nbsp;UAS with SFC, is useful in re-education of a transferred muscle, as desired movement can be achieved with low intensity.

Tension of the ulnar, median, and radial nerves during ulnar nerve neurodynamic testing: observational cadaveric study.

The ulnar nerve upper limb neurodynamic test (ULNT3) uses upper limb positioning to investigate symptoms arising from the ulnar nerve. It is proposed to selectively increase tension of the nerve; however, this property of the test is not well established. The aim of this study was to determine the upper limb position that results in: (1) the greatest tension of the ulnar nerve and (2) the greatest difference in tension between the ulnar nerve and the other 2 major nerves of the upper limb: median and radial. This was an observational cadaver study. Tension (in newtons) of the ulnar, median, and radial nerves was measured simultaneously using 3 buckle force transducers in 5 upper limb positions in 10 embalmed human cadavers (N=20 limbs). Repeated-measures analysis of variance (ANOVA) with Bonferroni post hoc tests determined differences in tension among nerves and among limb positions. The addition of shoulder horizontal abduction (H.Abd; 12.62 N; 95% confidence interval [95% CI]=10.76, 14.47) and combined shoulder abduction and internal rotation (H.Abd+IR; 11.86 N; 95% CI=9.96, 13.77) to ULNT3 (scapular depression, shoulder abduction and external rotation, elbow flexion, forearm pronation, and wrist and finger extension) produced significantly greater ulnar nerve tension compared with the ULNT3 alone (8.71 N; 95% CI=7.25, 10.17). The ULNT3+H.Abd test demonstrated the greatest difference in tension among nerves (mean difference between ulnar and median nerves=11.87 N; 95% CI=9.80, 13.92; mean difference between ulnar and radial nerves=8.47 N; 95% CI=6.41, 10.53). These results pertain only to the biomechanical plausibility of the ulnar nerve neurodynamic test and do not account for other factors that may affect the clinical application of this test. The ULNT3+H.Abd is a biomechanically plausible test for detecting peripheral neuropathic pain related to the ulnar nerve. In situations where the shoulder complex will not tolerate the combination of shoulder external rotation in abduction, performing upper limb neurodynamic tests with internal rotation instead of external rotation is a biomechanically plausible alternative.