Classification Of Nerve Injuries Research Articles

Median and Ulnar Nerve Repair Using Sural Nerve Graft: A Case Report

Abstract: Most peripheral nerve injuries (PNI) are caused by trauma. Upper extrimities are most likely to get injured, and the radial nerve is the most common part in upper extrimites to be affected. There are different surgical options available to repair PNI. We reported a 48-years-old male consulted to the Neurosurgery Department for right upper limb weakness and numbness. He had history of laceration due to iron sheeting in the right arm. There was an irregular scar, weakness on right lower arm with hypesthesia, but no neurovascular distal (NVD) abnormalities were found. Further examination showed claw hand. EMG examination revealed total lesion of the right median and ulnar nerve, partial lesion of the right radial nerve with the lesion at wrist level, possibly neurotmesis according to Seddon Classification. Initial debridement, suturing, and repairing of radial artery and flexor carpi ulnar tendon were performed. The patient was then diagnosed as total lesion of the right median and ulnar nerve, partial lesion of the right radial nerve, post repair right ulnar and radial artery and flexor carpi ulnar tendon repair with the planning of nerve graft with no complication under monitoring. The patient was scheduled for sural nerve graft procedure. Early nerve repair or reconstruction is needed even though it only results in incomplete recovery for months to years. The sural nerve is great either in diameter or length which can be a huge source for the grafting of nerve and revealed good outcomes. Recent study showed incomplete recovery especially seen when the patient could not fully clench his hand and his thumb did not move properly during the movement. In conclusion, sural nerve graft is an appropriate choice for peripheral nerve injuries with more benefits included. Prognosis depends on how early the treatment performed and how severe the lesion is. Keywords: median nerve; sural nerve; peripheral nerve injury; nerve repair; nerve grafting

Incorporating Blood Flow in Nerve Injury and Regeneration Assessment.

Peripheral nerve injury is a significant public health challenge, with limited treatment options and potential lifelong impact on function. More than just an intrinsic part of nerve anatomy, the vascular network of nerves impact regeneration, including perfusion for metabolic demands, appropriate signaling and growth factors, and structural scaffolding for Schwann cell and axonal migration. However, the established nerve injury classification paradigm proposed by Sydney Sunderland in 1951 is based solely on hierarchical disruption to gross anatomical nerve structures and lacks further information regarding the state of cellular, metabolic, or inflammatory processes that are critical in determining regenerative outcomes. This review covers the anatomical structure of nerve-associated vasculature, and describes the biological processes that makes these vessels critical to successful end-organ reinnervation after severe nerve injuries. We then propose a theoretical framework that incorporates measurements of blood vessel perfusion and inflammation to unify perspectives on all mechanisms of nerve injury.

Characteristic of Bell’s Palsy in Clinical Neurologic at Sanglah Hospital Denpasar Bali Indonesia

Introduction/Aim: Bell's Palsy is a lower motor neuron facial weakness caused by idiopathic etiology with the absence of other neurologic diseases. The incidence of this syndrome is around 23 cases per 100,000 people each year. The clinical manifestations are sometimes being considered to be a stroke or tumor. This study was conducted to find characteristic of bell’s palsy in clinical neurologic at Sanglah Hospital Denpasar, Bali Indonesia Methods: This study is a descriptive study with a cross sectional design in polyclinic of Sanglah Hospital, Denpasar for the period 2016 to 2019. Sampling was carried out using a consecutive non-random sampling method. Result: A total of 31 subjects in rainy season 51.6% having female 61.3% and male 38.7%, with the range of age 46-55 years old. Most of the patients complaints the weakness of the right face 58.1%, postauricular pain 64.5%. Electroneuromyography examination with seddon classification having results of Neuropraxia 67.7%. Conclusion: Characteristic of bell’s palsy in clinical neurologic most of participant in woman with postauricular pain and neuropraxia Keywords: Bell's Palsy, neuropraxia, postauricular pain, seddon classification.

Management of Traumatic Trigeminal and Facial Nerve Injuries.

In the area of craniomaxillofacial trauma, neurosensory disturbances are encountered commonly, especially with regard to the trigeminal and facial nerve systems. This article reviews the specific microanatomy of both cranial nerves V and VII, and evaluates contemporary neurosensory testing, current imaging modalities, and available nerve injury classification systems. In addition, the article proposes treatment paradigms for management of trigeminal and facial nerve injuries, specifically with regard to the craniomaxillofacial trauma setting.

How Many Oral Surgeons Does It Take to Classify a Nerve Injury?

There is inconsistency in clinical grading of peripheral trigeminal nerve (TN5) injuries that impact patient care. The study goal is to assess the current status of evaluation and classification of TN5 injuries by oral and maxillofacial surgeons (OMSs). A cross-sectional study design used an electronic survey to 100 selected OMSs to determine their clinical TN5 injury practice, including neurosensory testing, confidence level with current protocols, and evaluation and treatment of a hypothetical TN5 injury case. The target sample was enhanced to reduce type 2 error, assuming prior experience in the diagnosis and management of TN5 injuries. The sample was composed of 90 respondents. Nerve injury classification systems used by OMSs include Seddon (44%), Sunderland (70%), and Medical Research Council Scale (31%). Neurosensory testing protocols varied considerably among survey respondents. A sample case for Medical Research Council Scale grading produced inconsistent and inaccurate results. There was no consensus on TN5 injury management, and recommendations for timely nerve repair varied from 1month to up to 1year after injury. Half of the respondents stated that OMSs are not adequately prepared to assess inferior alveolar/lingual nerve injuries, and most oral-maxillofacial surgery respondents evaluate fewer than 10 TN5 injuries each year. Most OMSs (92%) have had a temporary inferior alveolar/lingual nerve injury, while 54% have had a permanent injury; of which, 21% required microsurgical repair. The majority of OMSs (74%) believed that a uniform TN5 injury classification system is needed. Within the oral-maxillofacial surgery target group experienced in evaluation of TN5 injuries, respondents do not feel confident in the assessment of these injuries. There is inconsistency in evaluation methods, and there is agreement that a unified classification system is needed for more efficient patient evaluation and reporting of outcomes in the literature. The Medical Research Council Scale and clinical neurosensory testing is preferred for evaluation of TN5 injuries.

Reflections on the History of Nerve Repair - Sir Sydney Sunderland's Final Presentation to the Neurosurgical Society of Australasia.

Sir Sydney Sunderland (1910-1993) was an eminent physician and anatomist who identified the fascicular structure of nerves, and developed the eponymous 5-tiered classification of nerve injuries. Not long before his death, he presented a keynote address to the Annual Scientific Meeting of the Neurosurgical Society of Australasia. Recently, the videotape of his presentation was discovered. In the presentation, Sir Sydney included discussion on the history of nerve repair, commencing with Herophilus and Galen, and progressing through the Middle Ages, including Leonardo of Bertapaglia, and he further noted the discoveries during the 1800s of the microscope, the axon, and nerve histology (including Remak, Schwann, Nissl, and Golgi), Waller's findings on nerve degeneration, and nerve injury (His, Cajal, Forsmann, and Harrison). Sir Sydney discussed nerve injuries sustained during World War I, with the deleterious effects of infection, and following the many nerve injuries sustained during World War II, he discussed his own discoveries of internal topography of nerve fascicles, and the anatomical substrate of nerve fascicles that limit surgery for nerve repair, nerve grafts, and the basic science of spinal cord repair. This paper presents a transcript of Sunderland's presentation and includes many of his original images used to illustrate this tour de force of nerve repair.

OUP accepted manuscript

Traumatic peripheral nerve injury is a worldwide clinical issue with high morbidity. The severity of peripheral nerve injury can be classified as neurapraxia, axonotmesis or neurotmesis, according to Seddon’s classification, or five different degrees according to Sunderland’s classification. Patients with neurotmesis suffer from a complete transection of peripheral nerve stumps and are often in need of surgical repair of nerve defects. The applications of autologous nerve grafts as the golden standard for peripheral nerve transplantation meet some difficulties, including donor nerve sacrifice and nerve mismatch. Attempts have been made to construct tissue-engineered nerve grafts as supplements or even substitutes for autologous nerve grafts to bridge peripheral nerve defects. The incorporation of stem cells as seed cells into the biomaterial-based scaffolds increases the effectiveness of tissue-engineered nerve grafts and largely boosts the regenerative process. Numerous stem cells, including embryonic stem cells, neural stem cells, bone marrow mesenchymal stem cells, adipose stem cells, skin-derived precursor stem cells and induced pluripotent stem cells, have been used in neural tissue engineering. In the current review, recent trials of stem cell-based tissue-engineered nerve grafts have been summarized; potential concerns and perspectives of stem cell therapeutics have also been contemplated.

Peripheral Nerve Injuries: Electrophysiology for the Neurosurgeon.

Peripheral nerve injuries are a heterogeneous and distinct group of disorders that are secondary to various causes commonly including motor vehicle accidents, falls, industrial accidents, household accidents, and penetrating trauma. The earliest classification of nerve injuries was given by Seddon and Sunderland, which holds true till date and is commonly used. Neuropraxia, axonotmesis, and neurotmesis are the three main types of nerve injuries. The electrophysiological studies including nerve conduction studies (NCS) and electromyography (EMG) play a key role and are now considered an extension of the clinical examination in patients with peripheral nerve injuries. The electrophysiological results should be interpreted in the light of clinical examination. These studies help in localizing the site of lesion, determine the type and severity of lesion, and help in prognosticating. In neuropraxia, the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) are elicitable on stimulating the nerve distal to the site of the lesion but demonstrate conduction block on proximal stimulation. The electrodiagnostic findings in axonotmesis and neurotmesis are similar. After few days of injury, Wallerian degeneration sets in with failure to record CMAP and SNAP. Intraoperative technique involves recording from the peripheral nerves during the intraoperative period and has proved useful in the surgical management of nerve injuries and helps in identifying the injured nerve, to determine whether the nerve is in continuity and in localizing the site of lesion. Intraoperative monitoring also helps in identifying the nerve close to an ongoing surgery so that surgical damage to the nerve can be prevented.

Role of MR Neurography for the Diagnosis of Peripheral Trigeminal Nerve Injuries in Patients with Prior Molar Tooth Extraction.

Clinical neurosensory testing is an imperfect reference standard to evaluate molar tooth extraction related peripheral trigeminal neuropathy. The purpose was to evaluate the diagnostic accuracy of MR neurography in this domain and correlation with neurosensory testing and surgery. In this retrospective study, nerve caliber, T2 signal intensity ratio, and contrast-to-noise ratios were recorded by 2 observers using MR neurography for bilateral branches of the peripheral trigeminal nerve, the inferior alveolar and lingual nerves. Patient demographics and correlation of the MR neurography findings with the Sunderland classification of nerve injury and intraoperative findings of surgical patients were obtained. Among 42 patients, the mean ± SD age for case and control patients were 35.8 ± 10.2 years and 43.2 ± 11.5 years, respectively, with male-to-female ratios of 1:1.4 and 1:5, respectively. Case subjects (peripheral trigeminal neuropathy or injury) had significantly larger differences in nerve thickness, T2 signal intensity ratio, and contrast-to-noise ratios than control patients for the inferior alveolar nerve and lingual nerve (P = .01 and .0001, .012 and .005, and .01 and .01, respectively). Receiver operating characteristic analysis showed a significant association among differences in nerve thickness, T2 signal intensity ratio, and contrast-to-noise ratios and nerve injury (area under the curve, 0.83-0.84 for the inferior alveolar nerve and 0.77-0.78 for the lingual nerve). Interobserver agreement was good for the inferior alveolar nerve (intraclass correlation coefficient, 0.70-0.79) and good to excellent for the lingual nerve (intraclass correlation coefficient, 0.75-0.85). MR neurography correlations with respect to clinical neurosensory testing and surgical classifications were moderate to good. Pearson correlation coefficients of 0.68 and 0.81 and κ of 0.60 and 0.77 were observed for differences in nerve thickness. MR neurography can be reliably used for the diagnosis of injuries to the peripheral trigeminal nerve related to molar tooth extractions, with good to excellent correlation of imaging with clinical findings and surgical results.

Factors Determining Outcome After Trigeminal Nerve Surgery for Neuropathic Pain

Most patients who seek relief from trigeminal neuropathic pain by trigeminal microneurosurgery techniques do not show permanent pain relief after surgery. However, a small number of patients have permanent relief after surgery. The objective of this study was to determine factors that might be associated with the resolution, decrease, or recurrence of neuropathic pain after trigeminal nerve surgery in those patients who present with neuropathic pain before surgery. An ambispective study design was used to assess patients who underwent trigeminal nerve repair of the inferior alveolar and lingual nerve who had documented neuropathic pain before surgery from 2006 through 2014. The primary endpoint was the difference in pain intensity at 3, 6, and 12months after surgery compared with presurgical intensity levels. Explanatory variables, including age at surgery, gender, site of nerve injury, etiology of nerve injury, classification of nerve injury, duration from injury to repair, health comorbidities, and type of repair performed, were evaluated as potential factors in the outcomes. Wilcoxon signed rank analysis was used to compare demographic and injury characteristics of patients who had pain relief, partial pain relief, and no pain relief after surgery. Two-way analysis of variance and logistic regression analysis were used to evaluate the association between neuropathic pain and the explanatory variables. Twenty-eight patients met the inclusion criteria. Three cohorts of patients were identified and analyzed. The no-recurrence cohort included 7 patients who had neuropathic pain before surgery that was resolved with surgery. The complete-recurrence (CR) cohort included 10 patients who had neuropathic pain before surgery and complete recurrence of pain intensity after surgery. The incomplete-recurrence (ICR) cohort included 11 patients who had neuropathic pain before surgery and partial recurrence of pain intensity after surgery. There was no statistical difference in preoperative pain intensity levels among the 3 cohorts (P= .16), but there were statistical differences at 3months (P= .007), 6months (P < .0001), and 12months (P < .0001). There were no statistical differences between the CR and ICR cohorts at 3months (P= .502), 6months (P= .1), and 12months (P= .2). There was no effect by age, gender, injury type, Sunderland classification, injury etiology, duration from injury to repair, health comorbidity, or repair type on the outcome. The recurrence of neuropathic pain after trigeminal nerve repair for neuropathic pain is likely multifactorial and might not depend on factors that normally affect sensory recovery in patients who have no neuropathic pain (ie, age, duration of injury, type of injury, or repair type) and undergo trigeminal nerve surgery. These differences indicate that the understanding of trigeminal neuropathic pain is incomplete. Predictive outcomes of treatment will probably improve when the etiology is better defined to allow target- and site-specific treatment. In the meantime, trigeminal nerve surgery is a treatment option that offers a chance of decreasing or resolving pain intensity.

The pattern of peripheral nerve injuries among Pakistani soldiers in the war against terror.

To determine the pattern of peripheral nerve injuries in Pakistani soldiers in the War against terror. Case series. Department of Electrodiagnosis at Armed Forces Institute of Rehabilitation Medicine (AFIRM), Rawalpindi, Pakistan, from June 2008 to June 2011. All new cases of war wounded soldiers with peripheral nerve injuries were consecutively enrolled. Physical examination and electrodiagnostic study was carried out by experienced physiatrists. Data was entered in pretested especially designed questionnaire which was analysed using SPSS version 17.0. Seddon's classification system was used to assess the severity of injury. There were 418 cases of peripheral nerve injuries with 504 different nerve segments. Mean age was 29.41 ±8 years. Blast was the main cause of nerve injury in 244 (48.5%) cases followed by gunshot in 215 (42.7%) and 45 (8.9%) cases had nerve injuries secondary to fall, burial under debris and motor vehicle accidents. Eighty six (17%) cases had multiple nerve injuries. Most commonly injured nerve was ulnar (20.6%) followed by sciatic (16.7%), median (16.5%), radial (16.3%), peroneal (8.7%), brachial plexus (8.5%), axillary (4.8%), tibial (2%), femoral (1.8%), long thoracic (0.4%) and others (3.8%). Axonotmesis was seen in 459 (91.1%) cases, 44 (8.7%) cases revealed neurotmesis and 1 (0.2%) case had neuropraxia. Peripheral nerve injuries are a major component of war related injuries mainly involving the upper limbs. Electrodiagnostic studies help in assessing severity and determining prognosis. Precise documentation of severity of nerve injuries is important to estimate the burden on our resources and to extend rehabilitation services.

Oštećenja perifernih nerava uzrokovana primenom periferne intravenske terapije

Introduction: The objective of the current study was to present data on peripheral nerve injury related to peripheral intravenous therapy obtained through the use of empirical studies and analysis. Materials and Methods: To detect empirical studies, we developed search strategies for use in Medline electronic database, using only related keywords, based on MeSH terms: peripheral nerve injuries, peripheral nerve damage, peripheral intravenous therapy, venipuncture, periphera lintravenous cannulation. The studies included in this analysis were published in English. Results: The likelihood of peripheral nerve injury related to venipuncture and peripheral intravenous cannulation is often citedin the research literature. However, there have been more frequent reports of nerve injury consequent on venepuncture in comparison to rare case reports of peripheral nerve injury from intravenous cannulation. Based on Seddon's classification of nerve injuries, a review of the literature shows incidence of all three types of injury. Conclusions: Peripheral intravenous therapy is the most common procedures performed by nurses in their everyday clinical practice, can cause different types of damage to the peripheral nerves.

Sir Herbert Seddon (1903-1977) and his classification scheme for peripheral nerve injury.

Sir Herbert Seddon was a visionary neuroscientist and surgeon. Internationally, he is best known for his classification of the peripheral nerve injury, now known as Seddon's classification. The authors reviewed his life with a special emphasis on his legacy to neuroscience.

The Presence of Neuropathic Pain Predicts Postoperative Neuropathic Pain Following Trigeminal Nerve Repair

The risk for the continuation or recurrence of neuropathic pain following trigeminal nerve repair has never been examined. The objective of this study was to determine which risk factors might be associated with the continuation or recurrence of neuropathic pain following trigeminal nerve microneurosurgery. An ambispective study design was used to assess subjects who underwent trigeminal nerve repair of the inferior alveolar nerve and lingual nerve between 2000 and 2010. The primary outcome was the presence or absence of neuropathic pain at 3, 6, and 12 months after surgery. Explanatory variables, including age at surgery, gender, presence of neuropathic pain before surgery, site of nerve injury, etiology of nerve injury, classification of nerve injury, duration of nerve injury, and type of repair performed, were abstracted from patient charts. Fisher exact tests were used to compare the demographic and injury characteristics of patients who presented with pain before surgery and those who did not. The McNemar test was used to assess whether there was a significant change in neuropathic pain report from before to after surgery. The level of significance was set at .50. Of the 65 patients analyzed, two-thirds were women; the average age was 36±16.1 years, and the median time between the injury and surgery was 6.4 months (interquartile range, 6.7 months). Lingual nerve injury type was the most frequent (62%). There was no statistically significant change in pain status from before to after surgery (P=.104). Only 1 patient had pain after surgery who had not had pain before surgery, while 67% of those with pain before surgery continued to have pain after surgery. Pain prior to surgery as a predictor of pain after had sensitivity of 91%, specificity of 88%, positive predictive value of 67%, and negative predictive value 97%. The presence of neuropathic pain prior to trigeminal microneurosurgery is the major risk factor for the continuation or recurrence of postoperative neuropathic pain. These findings suggest that trigeminal nerve surgery is not a risk factor for developing neuropathic pain in the absence of neuropathic pain before surgery.

Peripheral nerve injury grading simplified on MR neurography: As referenced to Seddon and Sunderland classifications.

The Seddon and Sunderland classifications have been used by physicians for peripheral nerve injury grading and treatment. While Seddon classification is simpler to follow and more relevant to electrophysiologists, the Sunderland grading is more often used by surgeons to decide when and how to intervene. With increasing availability of high-resolution and high soft-tissue contrast imaging provided by MR neurography, the surgical treatment can be guided following the above-described grading systems. The article discusses peripheral nerve anatomy, pathophysiology of nerve injury, traditional grading systems for classifying the severity of nerve injury, and the role of MR neurography in this domain, with respective clinical and surgical correlations, as one follows the anatomic paths of various nerve injury grading systems.

The Characteristics of Chronic Inflammatory Demyelinating Polyneuropathy in Patients with and without Diabetes – An Observational Study

IntroductionWe aimed to determine whether the clinical characteristics and electrodiagnostic classification of nerve injury, and response to treatment differed in patients diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) with and without diabetes.MethodsCIDP patients with diabetes (CIDP+DM) (n = 67) and without diabetes (CIDP-DM) (n = 67) underwent clinical examination and nerve conduction studies (NCS). CIDP-DM patients were selected using age and gender matching with the existing CIDP+DM cohort. Patients treated with immunotherapies were classified as responders (R) (n = 46) or non-responders (NR) (n = 54) based on clinical response to treatment. The groups were compared using analysis of variance, contingency tables and Kruskal-Wallis analyses.ResultsCIDP+DM subjects had more severe neuropathy based on higher lower limb vibration potential thresholds (VPT)(p = 0.004), higher Toronto Clinical Neuropathy Score (TCNS) (p = 0.0009), more proximal weakness (p = 0.03), more gait abnormality (p = 0.03) and more abnormal NCS. CIDP+DM subjects had more abnormal sural NCS with lower sural sensory nerve action potential amplitudes (2.4±3.0 µV, 6.6±6.0 µV, p<0.0001) and slower sural nerve conduction velocities (38.6±5.4 m/s, 41.0±5.3 m/s, p = 0.04). CIDP-DM subjects were more likely to receive immune therapies (93% vs 57%, p = <0.0001), despite no significant differences in treatment responder rates (p = 0.71). Patients who responded to therapy had shorter duration of CIDP than non-responders (8.0±6.0 y vs 11.9±7.6 y, p = 0.004).DiscussionThe clinical phenotype and electrophysiological profile of CIDP patients differs according to the presence or absence of diabetes. Despite CIDP+DM patients having more severe clinical and electrophysiological neuropathy, they are less likely to receive disease-modifying/specific therapy, yet have similar response rates to treatment as those without diabetes. Specifically, the duration of neuropathy - not diabetes status - was associated with treatment response.

Comparison of diabetes patients with “demyelinating” diabetic sensorimotor polyneuropathy to those diagnosed with CIDP

BackgroundWe have previously identified a subset of diabetic sensorimotor polyneuropathy (DSP) patients with probable demyelination related to poor glycemic control. We aimed to determine whether the clinical characteristics and electrodiagnostic classification of nerve injury in diabetes patients with “demyelinating” DSP (D-DSP) differed from those diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) (CIDP + diabetes mellitus [DM]).MethodsD-DSP (56) and CIDP + DM (67) subjects underwent clinical examination and nerve conduction studies (NCS), and were compared using analysis of variance, contingency tables, and Kruskal–Wallis analyses.ResultsOf the 123 subjects with a mean age of 60.5 ± 15.6 years and mean hemoglobin A1c (HbA1c) of 8.2 ± 2.2%, 54% had CIDP + DM and 46% had D-DSP. CIDP + DM subjects were older (P = 0.0003), had shorter duration of diabetes (P = 0.005), and more severe neuropathy as indicated by Toronto Clinical Neuropathy Score (TCNS) (P = 0.003), deep tendon reflexes (P = 0.02), and vibration perception thresholds (VPT) (P = 0.01, P = 0.02). The mean HbA1c value for D-DSP subjects (8.9 ± 2.3%) was higher than in CIDP + DM subjects (7.7 ± 2.0%, P = 0.02).ConclusionsThe clinical phenotype and electrophysiological profile of CIDP + DM patients is marked by more severe neuropathy and better glycemic control than in patients with D-DSP. These findings indicate that these two conditions – despite similarities in their electrophysiological pattern of demyelination – likely differ in etiology.

Reparatur- und Rekonstruktionsverfahren der Nn. lingualis und alveolaris inferior

Peripheral nerve lesions in continuity with physically intact external appearance are distinguished from injuries with loss of continuity. The 3-type injury grading system of Seddon or preferably the 5 or 6 degree Sunderland classification are the most used predictors of peripheral nerve damage, their capacity for spontaneous regeneration and the need for surgically assisted recovery. Peripheral nerve lesions caused by local neurotoxic effects are lesions in continuity with blocks through the perineurium due to scar tissue formation that precludes axonal sprouting and regeneration. The presented articles deal with the repair and reconstruction of lingual nerve injuries in different scenarios (trauma and tumor resection) with focus on accidental (iatrognic) lesions. Part 1 presents the classification of nerve injuries and terminology, the diagnostic evaluation as well as particular anatomical features and details of the surgical approaches.

A NIR Dye for Development of Peripheral Nerve Targeted Probes.

Current imaging modalities lack the ability to quickly assess and classify nerve injury for predicting favourable versus unfavourable healing outcomes, which could minimize episodes of chronic pain and loss of function by allowing for early intervention. Thus, the development of a technique to noninvasively assess peripheral nerve damage is of critical importance. While the development of nerve specific near infrared (NIR) molecular probes capable of such diagnostics constitutes our long term goal, initial studies to identify a NIR dye for constructing such a probe are required. We have evaluated the properties of a novel highly hydrophilic and functionalizable polymethine dye, and its more hydrophobic analogue indocyanine green, within the sciatic nerve of rats following intra-nerve injection. The reporting ability of both dyes at critical depths for nerve imaging, the importance of hydrophilicity on dye transport through nervous tissue, and their toxicity - or lack thereof - to the neural environment have been evaluated. The results suggest that the novel NIR dye is an appropriate fluorescent reporter for use in designing nerve-specific optical molecular probes for non-invasive diagnosis and classification of nerve injury.

Cervical Transforaminal Epidural Injection in the Management of a Stinger

A “stinger,” otherwise known as a “burner,” is a transient, reversible peripheral nerve injury of the upper limb caused by injury to the cervical spine and shoulder. This injury usually occurs during participation in contact sports [1-3]. Stingers are considered to be underreported by athletes and are most common in American-style football, hockey, gymnastics, and wrestling [4]. In a study of collegiate American-style football players, Levitz et al [5] reported that stingers occur in 50%-65% of these athletes during the course of their career; they also reported high rates of recurrence. Mechanisms of injury include traction, compression, and direct blows [4,6-9]. Traction injuries result from ipsilateral shoulder depression and contralateral neck flexion, effectively resulting in traction on the nerve root and/or brachial plexus. At the high school level, football players are more likely to have traction injuries. Conversely, compression injuries are more likely sustained at the collegiate and professional levels [10]. Compression injuries of the nerve root stem from a combination of forced hyperextension with ipsilateral rotation and lateral flexion leading to transient neuroforaminal narrowing. Finally, a direct blow to the supraclavicular region (Erb point), where the brachial plexus is most superficial, can result in direct trauma to the plexus. Most stingers, according to the Seddon classification scheme, are characterized as firstor second-degree peripheral nerve injuries, which refer to neurapraxia (demyelination) or axonotmesis (axonal loss), respectively. A third-degree injury, or neurotmesis (complete nerve transection), is not considered within the spectrum of this disorder [11,12]. Because tackling and blocking are the two most common mechanisms of stingers, defensive backs and offensive linemen are most susceptible [10]. Symptoms appear immediately after contact [1] and generally affect the upper trunk of the brachial plexus or C5/C6 erve roots [6-8,13-15]. The primary symptom is burning pain referring to the upper limb, hich may be accompanied by weakness, numbness, and paresthesias [1,16]. Symptoms typically do not last more than 24 hours [2]. A wide range of clinical courses have been described after a stinger injury, ranging from full recovery in seconds or hours to the development of a chronic syndrome [1,5]. The distribution of weakness is dependent on the source of the nerve injury, but whether it is the root (C5 or C6) or upper trunk of the brachial plexus, the most common pattern of muscle weakness involves the deltoid, supraspinatus, and/or infraspinatus for several weeks after the injury [17]. Conflicting views exist regarding the location of the neurological lesion [13]. Some authors who included an electrodiagnostic evaluation in their studies reported a greater incidence of brachial plexus involvement [8,14,15,18]. However, Slipman et al [19] demonstrated that diagnostic cervical selective nerve root blocks frequently provoke symptoms outside the classic dermatomal distribution in nonathletes. Thus it is plausible that injury to a single nerve root can produce a more circumferential pattern of symptoms in the upper limb [20]. Several factors suggest that most stingers are caused by cervical nerve root injury [5,21]. It has been shown that there is a statistically significant 10%-13% decrease in neuroforaminal diameter when the neck is positioned in 20°-30° of extension, as is common during a stinger injury [22]. Anatomically, the cervical nerve roots appear to be more vulnerable to injury than the brachial plexus because of their orientation and