Preganglionic Injury of C8 Nerve Root Secondary to Shoulder Disloca tion: Diagnosis based on MRI Findings.

INTRODUCTION: Traumatic spinal root injury caused by shoulder dislocation may involve the brachial plexus or, in some cases, a single nerve. The degree of severity of the injury depends on many patient-specific factors as well as the mechanism of injury. It is essential to suspect this type of lesion by means of a thorough physical examination in order to have better patient outcomes. CASE PRESENTATION: We presented the subtle magnetic resonance imaging (MRI) findings in a 35-yearold male with left shoulder trauma and dislocation after falling off a bicycle. He complained of decreased muscle strength and sensitivity in the C8 dermatome. Atrophy of the hypothenar region and flexion deformity of the 4th and 5th digits were noted. Magnetic resonance imaging findings were consistent with a partial preganglionic C8 motor root lesion. We found T2 increased signal intensity and thinning of the intradural segment of the C8 motor nerve root and low signal in the sequence of a multi- echo gradient recalled echo (GRE). CONCLUSION: MRI is a noninvasive tool that allows a detailed anatomical characterization of the nerves. In brachial plexus injuries, the use of the GRE sequence is useful to identify the lesions, even if they are subtle; however, some lesions may go unnoticed. It is important to note that these patients require an interdisciplinary group to reach a correct diagnosis, which is vital to establish the appropriate treatment and follow-up.

Raman spectroscopy and sciatic functional index (SFI) after low-level laser therapy (LLLT) in a rat sciatic nerve crush injury model.

Axonotmesis causes sensorimotor and neurofunctional deficits, and its regeneration can occur slowly or not occur if not treated appropriately. Low-level laser therapy (LLLT) promotes nerve regeneration with the proliferation of myelinating Schwann cells to recover the myelin sheath and the production of glycoproteins for endoneurium reconstruction. This study aimed to evaluate the effects of LLLT on sciatic nerve regeneration after compression injury by means of the sciatic functional index (SFI) and Raman spectroscopy (RS). For this, 64 Wistar rats were divided into two groups according to the length of treatment: 14 days (n = 32) and 21 days (n = 32). These two groups were subdivided into four sub-groups of eight animals each (control 1; control 2; laser 660 nm; laser 808 nm). All animals had surgical exposure to the sciatic nerve, and only control 1 did not suffer nerve damage. To cause the lesion in the sciatic nerve, compression was applied with a Kelly clamp for 6 s. The evaluation of sensory deficit was performed by the painful exteroceptive sensitivity (PES) and neuromotor tests by the SFI. Laser 660 nm and laser 808 nm sub-groups were irradiated daily (100 mW, 40 s, energy density of 133 J/cm2). The sciatic nerve segment was removed for RS analysis. The animals showed accentuated sensory and neurofunctional deficit after injury and their rehabilitation occurred more effectively in the sub-groups treated with 660 nm laser. Control 2 sub-group did not obtain functional recovery of gait. The RS identified sphingolipids (718, 1065, and 1440 cm-1) and collagen (700, 852, 1004, 1270, and 1660 cm-1) as biomolecular characteristics of sciatic nerves. Principal component analysis revealed important differences among sub-groups and a directly proportional correlation with SFI, mainly in the sub-group laser 660 nm treated for 21 days. In the axonotmesis-type lesion model presented herein, the 660 nm laser was more efficient in neurofunctional recovery, and the Raman spectra of lipid and protein properties were attributed to the basic biochemical composition of the sciatic nerve.

Functional Recovery Occurs Even After Partial Remyelination of Axon-Meshed Median and Ulnar Nerves in Mice.

Upper limb nerve injuries are common, and their treatment poses a challenge for physicians and surgeons. Experimental models help in minimum exploration of the functional characteristics of peripheral nerve injuries of forelimbs. This study was conducted to characterize the functional recovery (1, 3, 7, 10, 14, and 21 days) after median and ulnar nerve crush in mice and analyze the histological and biochemical markers of nerve regeneration (after 21 days). Sensory-functional impairments appeared after 1 day. The peripheral nerve morphology, the nerve structure, and the density of myelin proteins [myelin protein zero (P0) and peripheral myelin protein 22 (PMP22)] were analyzed after 21 days. Cold allodynia and fine motor coordination recovery occurred on the 10th day, and grip strength recovery was observed on the 14th day after injury. After 21 days, there was partial myelin sheath recovery. PMP22 recovery was complete, whereas P0 recovery was not. Results suggest that there is complete functional recovery even with partial remyelination of median and ulnar nerves in mice.

Sciatic nerve injection palsy in a dog: electrodiagnostic testing and microsurgical treatment

Background: Iatrogenic damage to the ischiatic nerve is considered uncommon and may cause dysfunction with variable clinical signs dependent on type and severity of injury. Due to important role of this nerve in locomotion and weightbearing limb, a poor prognosis for recovery may be observed in many cases. Electromyography analysis may suggest the neuroanatomic localization, diagnosis information, and severity of lesion to determine better therapeutic intervention. Therefore, the aim of this report is to describe the possible cause, diagnosis and treatment of a postinjection ischiatic nerve injury in a dog with complete recovery.Case: A 3-year-old neutered male dachshund dog was referred to the Veterinary Hospital due to inability to weight support in the right hind limb after diminazene diaceturate intramuscular injection. The gait evaluation showed dropped-hock and knuckling into the digits of the right hind limb and neurologic examination revealed moderate muscle atrophy below to femorotibial joint of the right hind limb with sensory analgesia (superficial and deep) on the lateral, dorsal, and plantar surfaces, absent patellar reflex, and proprioceptive deficit. Electrophysiologic testing was done under general anesthesia in a 2-channel Nicolet Compass Meridian apparatus. Absence of compound muscle action potentials after right fibular and tibial nerve stimulations, and abnormal spontaneous activity in cranial tibial, gastrocnemius and deep digital extensor muscles were observed. A diagnosis of moderate/severe axonotmesis of sciatic nerve was achieved. Under microscope magnification, all adherent adjacent tissue and epineural sheat were removed. Due this, a small epineural window was created. On neurological examination performed 30 days after surgery, complete recovery of sensitivity of the right hind limb, and normal proprioception were observed. The muscle atrophy was also noted to have improved.[...]

Sciatic nerve injection palsy in a dog: electrodiagnostic testing and microsurgical treatment

Background: Iatrogenic damage to the ischiatic nerve is considered uncommon and may cause dysfunction with variable clinical signs dependent on type and severity of injury. Due to important role of this nerve in locomotion and weightbearing limb, a poor prognosis for recovery may be observed in many cases. Electromyography analysis may suggest the neuroanatomic localization, diagnosis information, and severity of lesion to determine better therapeutic intervention. Therefore, the aim of this report is to describe the possible cause, diagnosis and treatment of a postinjection ischiatic nerve injury in a dog with complete recovery.Case: A 3-year-old neutered male dachshund dog was referred to the Veterinary Hospital due to inability to weight support in the right hind limb after diminazene diaceturate intramuscular injection. The gait evaluation showed dropped-hock and knuckling into the digits of the right hind limb and neurologic examination revealed moderate muscle atrophy below to femorotibial joint of the right hind limb with sensory analgesia (superficial and deep) on the lateral, dorsal, and plantar surfaces, absent patellar reflex, and proprioceptive deficit. Electrophysiologic testing was done under general anesthesia in a 2-channel Nicolet Compass Meridian apparatus. Absence of compound muscle action potentials after right fibular and tibial nerve stimulations, and abnormal spontaneous activity in cranial tibial, gastrocnemius and deep digital extensor muscles were observed. A diagnosis of moderate/severe axonotmesis of sciatic nerve was achieved. Under microscope magnification, all adherent adjacent tissue and epineural sheat were removed. Due this, a small epineural window was created. On neurological examination performed 30 days after surgery, complete recovery of sensitivity of the right hind limb, and normal proprioception were observed. The muscle atrophy was also noted to have improved.[...](AU)

The role of magnetic resonance imaging in the evaluation of peripheral nerves following traumatic lesion: where do we stand?

BACKGROUND: Peripheral nerve injury is a common and important cause of morbidity and disability in patients who have suffered a traumatic injury, particularly younger people. Various different injuries can result in damage to specific nerves. In patients with multiple trauma, the prevalence of peripheral nerve injury is estimated at 2.8%, but can reach 5% with the inclusion of brachial plexus involvement. Physical examination, as well as the origin and location of the trauma, can indicate the nerve involved and the type of nerve damage. However, the depth and severity of damage, and the structures involved often cannot be determined initially, but depend on longer periods of observation to reach a definitive and accurate diagnosis for which treatment can be proposed. Current approaches to locate and assess the severity of traumatic nerve injury involve clinical and electrodiagnostic studies. From a clinical and neurophysiological point of view, nerve injuries are classified in an attempt to correlate the degree of injury with symptoms, type of pathology, and prognosis, as well as to determine the therapy to be adopted. OBJECTIVES: MRI in the diagnosis of traumatic peripheral nerve injury has increasingly been used by surgeons in clinical practice. In this article, we analyze the use of magnetic resonance (MR) for the evaluation of traumatic peripheral nerve diseases that are surgically treatable. We also consider basic concepts in the evaluation of technical and MR signs of peripheral nerve injuries. MATERIALS AND METHODS: Studies were identified following a computerized search of MEDLINE (1950 to present), EMBASE (1980 to present), and the Cochrane database. The MEDLINE search was conducted on PUBMED, the EMBASE search was conducted on OVID, and the Cochrane database was conducted using their online library. A set was created using the terms: 'traumatic', 'nerve', and 'resonance'. RESULTS: The included articles were identified using a computerized search and the resulting databases were then sorted according to the inclusion and exclusion criteria. This yielded 10,340 articles (MEDLINE, n = 758; EMBASE, n = 9564; and Cochrane, n = 18). A search strategy was then built by excluding articles that only concern plexus injury and adding the terms 'neuropathies', 'DTI' and 'neurotmesis'. In total, seven studies were included in the review effectively addressing the role of MRI in the evaluation of traumatic peripheral nerve injury. We extracted all relevant information on the imaging findings and the use of magnetic resonance in trauma. We did not include technical or specific radiological aspects of the imaging techniques. CONCLUSIONS: These seven articles were subsequently evaluated by analyzing their results, methodological approach, and conclusions presented.

Hydroalcoholic extract of red propolis promotes functional recovery and axon repair after sciatic nerve injury in rats.

CONTEXT: Peripheral axon injury and degeneration are often mediated by oxidative stress and inflammation. The hydroalcoholic extract of the red propolis (HERP) has attracted great attention because of its antioxidant and anti-inflammatory activities. OBJECTIVE: The objective of this work is to study the effect of HERP on nerve repair and functional recovery after sciatic nerve injury (SNI) in rats. MATERIALS AND METHODS: The chemical markers in HERP were identified using high-resolution mass spectroscopy. After axonotmesis of sciatic nerve, ibuprofen (IBP) and HERP treatments were orally administered for 28 d. Behavioural tests were performed weekly after SNI. The myelinated axon number was counted using morphometric analysis. RESULTS: The compounds found in HERP were pinocembrin, formononetin, vestitol, and biochanin A. The animals that underwent SNI showed a significant decrease in motor function based on the Basso, Beattie and Bresnahan scale and sciatic functional index compared with sham animals until 7 d after the surgery (p < 0.05). After 14 and 21 d, the SNI groups treated with either HERP or IBP showed significant improvement (p < 0.01), and the SNI group treated with HERP 10 mg/kg showed accelerated motor recovery compared with the other groups (p < 0.01). SNI caused also a reduction in the myelinated axon counts, and treatment with HERP 10 mg/kg induced a significant increase in the number of myelinated fibres compared with all other groups. CONCLUSION: HERP promoted regenerative responses and accelerated functional recovery after sciatic nerve crush. Thus, it can be considered to be a new strategy or complementary therapy for treating nerve injuries.