Magnetic resonance imaging for detecting root avulsions in traumatic adult brachial plexus injuries: protocol for a systematic review of diagnostic accuracy

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.

Advancements in autologous peripheral nerve transplantation care: a review of strategies and practices to facilitate recovery

Autologous peripheral nerve transplantation, a pioneering technique in nerve injury treatment, has demonstrated remarkable progress. We examine recent nursing strategies and methodologies tailored to various anatomical sites, highlighting their role in postoperative recovery enhancement. Encompassing brachial plexus, upper limb, and lower limb nerve transplantation care, this discussion underscores the importance of personalized rehabilitation plans, interdisciplinary collaboration, and innovative approaches like nerve electrical stimulation and nerve growth factor therapy. Moreover, the exploration extends to effective complication management and prevention strategies, encompassing infection control and pain management. Ultimately, the review concludes by emphasizing the advances achieved in autologous peripheral nerve transplantation care, showcasing the potential to optimize postoperative recovery through tailored and advanced practices.

Non-contrast enhancement of brachial plexus magnetic resonance imaging with compressed sensing

PURPOSE

To observe the quality of brachial plexus (BP) images obtained from magnetic resonance imaging (MRI) with 3D T2 STIR SPACE sequence and compressed sensing (CS) and to compare the results with BP images from the same sequence without CS.

METHODS

In this study, compressed sensing was applied to acquire non-contrast BP images from ten healthy volunteers with 3D T2 STIR SPACE sequence to shorten acquisition time without sacrificing image quality. The acquisition time of scanning with CS was compared to that without CS. The quantitative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared using paired t-test to determine the quality of images with and without CS. The qualitative assessment by three experienced radiologists was performed using a scoring scale from 1 (poor) to 5 (excellent) and analyzed for interobserver agreement on image quality.

RESULTS

The increasing SNR and CNR of images with CS were found in nine regions of BP images (p < 0.001) with faster acquisition time. The result of paired t-test (p < 0.001) illustrates the significant difference between images with CS compared to images without CS. The assessment of observers also shows higher scores for images with CS compared to images without CS.

CONCLUSIONS

This study demonstrates that CS can effectively increase the visibility of images and image boundaries, SNR, and CNR of BP images obtained with 3D T2 STIR SPACE sequence with the good interobserver agreement and within clinically optimal acquisition time compared to images from similar sequence without CS.

A Decade of Imaging Patients with Traumatic Brachial Plexopathy: What have We Learned?

Aim  In this paper, the authors share their experience of imaging patients with traumatic brachial plexopathy by magnetic resonance neurography (MRN) spanning over a period of nearly 10 years. Setting and Design  This was a single-institution, prospective, observational study conducted between August 2012 and March 2022. Materials and Methods  Children and adults presenting to the plastic surgery outpatient department with features of traumatic brachial plexopathy were included in the study. The MRN study was performed in a 1.5T scanner (Magnetom Essenza, Siemens, Erlangen, Germany). The area scanned extended from C3 level to T3 level. Statistical Analysis Descriptive statistics (percentages, mean, median, and mode). Results  A total of 134 patients ( n  = 134) were included in the study. The age of our patients ranged from 6 months to 65 years. The mean age was 24.95 ± 12.10 years, with a median of 23 years. All patients had unilateral injury, and the right side was more commonly involved. Road traffic accident was the most common mode of injury, and blunt crush-avulsion was the most common mechanism of injury. Involvement of shoulder, elbow, and hand together (panplexopathy) was the most common clinical presentation. Conclusion  This study of patients with traumatic brachial plexopathy imaged by MRN, spanning nearly a decade, has led to several interesting observations. The majority of these injuries occur in young men from urban areas who usually present with panplexopathy. The most common mode of injury is road traffic accident, and blunt crush-avulsion is the most common mechanism of injury.

Diagnostic accuracy of magnetic resonance imaging for nerve injury in obstetric brachial plexus injury: protocol for systematic review and meta-analysis

BACKGROUND

Early and accurate clinical diagnosis of the extent of obstetric brachial plexus injury (OBPI) is challenging. The current gold standard for delineating the nerve injury is surgical exploration, and synchronous reconstruction is performed if indicated. Magnetic resonance imaging (MRI) is a non-invasive method of assessing the anatomy and severity of nerve injury in OBPI but the diagnostic accuracy is unclear. The primary objective of this review is to determine the diagnostic accuracy of MRI in comparison to surgical brachial plexus exploration for detecting root avulsion in children under 5 with OBPI. The secondary objectives are to determine its' diagnostic accuracy for detecting nerve abnormality and detecting pseudomeningocele(s) in this group.

METHODS

This review will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA).We will include studies reporting the accuracy of MRI (index test) compared to surgical exploration (reference standard) in detecting any of the three target conditions (root avulsion, any nerve abnormality and pseudomeningocele) in children under five with OBPI. Case reports and studies where the number of true positives, false positives, true negatives and false negatives cannot be derived will be excluded. We plan to search PubMed, Embase and CENTRAL for relevant studies from database inception to 15 June 2022. We will also search grey literature (medRxiv, bioRxiv and Google Scholar) and perform forward and backward citation chasing. Screening and full-text assessment of eligibility will be conducted by two independent reviewers, who will then both extract the relevant data. The QUADAS-2 tool will be used to assess methodological quality and risk of bias of included studies by two reviewers independently. The following test characteristics for the target conditions will be extracted: true positives, false positives, true negatives and false negatives. Estimates of sensitivity and specificity with 95% confidence intervals will be shown in forest plots for each study. If appropriate, summary sensitivities and specificities for target conditions will be obtained via meta-analyses using a bivariate model.

DISCUSSION

This study will aim to clarify the diagnostic accuracy of MRI for detecting nerve injury in OBPI and define its clinical role.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021267629.

MRI of the intraspinal nerve roots in patients with chronic inflammatory neuropathies: abnormalities correlate with clinical phenotypes

OBJECTIVE

Chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) are caused by inflammatory changes of peripheral nerves. It is unknown if the intra-spinal roots are also affected. This MRI study systematically visualized intra-spinal nerve roots, i.e., the ventral and dorsal roots, in patients with CIDP, MMN and motor neuron disease (MND).

METHODS

We performed a cross-sectional study in 40 patients with CIDP, 27 with MMN and 34 with MND. All patients underwent an MRI scan of the cervical intra-spinal roots. We systematically measured intra-spinal nerve root sizes bilaterally in the transversal plane at C5, C6 and C7 level. We calculated mean nerve root sizes and compared them between study groups and between different clinical phenotypes using a univariate general linear model.

RESULTS

Patients with MMN and CIDP with a motor phenotype had thicker ventral roots compared to patients with CIDP with a sensorimotor phenotype (p = 0.012), while patients with CIDP with a sensory phenotype had thicker dorsal roots compared to patients with a sensorimotor phenotype (p = 0.001) and with MND (p = 0.004).

CONCLUSION

We here show changes in the morphology of intra-spinal nerve roots in patients with chronic inflammatory neuropathies, compatible with their clinical phenotype.

ACR Appropriateness Criteria® Plexopathy: 2021 Update

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Dorsal Root Injury-A Model for Exploring Pathophysiology and Therapeutic Strategies in Spinal Cord Injury

Unraveling the cellular and molecular mechanisms of spinal cord injury is fundamental for our possibility to develop successful therapeutic approaches. These approaches need to address the issues of the emergence of a non-permissive environment for axonal growth in the spinal cord, in combination with a failure of injured neurons to mount an effective regeneration program. Experimental in vivo models are of critical importance for exploring the potential clinical relevance of mechanistic findings and therapeutic innovations. However, the highly complex organization of the spinal cord, comprising multiple types of neurons, which form local neural networks, as well as short and long-ranging ascending or descending pathways, complicates detailed dissection of mechanistic processes, as well as identification/verification of therapeutic targets. Inducing different types of dorsal root injury at specific proximo-distal locations provide opportunities to distinguish key components underlying spinal cord regeneration failure. Crushing or cutting the dorsal root allows detailed analysis of the regeneration program of the sensory neurons, as well as of the glial response at the dorsal root-spinal cord interface without direct trauma to the spinal cord. At the same time, a lesion at this interface creates a localized injury of the spinal cord itself, but with an initial neuronal injury affecting only the axons of dorsal root ganglion neurons, and still a glial cell response closely resembling the one seen after direct spinal cord injury. In this review, we provide examples of previous research on dorsal root injury models and how these models can help future exploration of mechanisms and potential therapies for spinal cord injury repair.

The relationship between alexithymia, sensory phenotype and neurophysiological parameters in patients with chronic upper limb neuropathy

In this study, we investigated the relationship between sensory abnormalities evaluated by quantitative sensory testing (QST) and alexithymia, depression and anxiety in patients with neuropathic pain involving the upper limbs. We enrolled 62 patients (34 with carpal tunnel syndrome, 7 with brachial plexopathy, 3 with cervical painful radiculopathy, 5 with ulnar entrapment neuropathy at elbow and 13 with post-burn hypertrophic scars) and 48 healthy controls. All underwent nerve conduction studies (NCS), evaluation of cold, heat pain and vibration detection threshold (VDT) by QST and evaluation of alexithymia by Toronto Alexithymia Scale (TAS-20), depression by Beck Depression Inventory II (BDI-II), anxiety by State-Trait Anxiety Inventory (STAI-Y), level of psychological distress by 12-item General Health Questionnaire (GHQ-12) and perceived social support by the Multidimensional Scale of Perceived Social Support (MSPSS). The general linear model analysis revealed a significant relationship between TAS-20 overall and TAS-20 sub-score for difficulty identifying feelings and VDT z-scores in the left index with no interaction by year of education and sensory NCS results. Our results demonstrated the association between impairment of vibratory sensation of the left hand, reflecting cutaneous mechanoceptor dysfunction, and alexithymia, particularly the difficulty to identify feelings. The importance of delivering to patients with neuropathic pain personalized care that takes into account not only the neurophysiological aspects but also the aspects of mental functioning is discussed.

Clinical, Electrodiagnostic Findings and Quality of Life of Dogs and Cats with Brachial Plexus Injury

Brachial plexus injury (BPI) represents a common consequence of road traffic accidents in humans and small animals. In humans, neuropathic pain is a common symptom after BPI. The aim of the study was to describe the clinical signs, the electrodiagnostic findings, the outcome and the quality of life (QoL) of a cohort of dogs and cats with BPI. Clinical records of 40 dogs and 26 cats with BPI were retrospectively reviewed. Specific attention was put on the evaluation of electrodiagnostic findings (35/40 dogs; 14/26 cats) and telephonic interview results (26/40 dogs; 18/26 cats). The most common neurological condition was the inability to bear weight and sensory deficits on the affected limb. Radial and ulnar motor nerve conduction studies (MNCSs) were absent respectively in 47% (radial) and 62% (ulnar) of dogs and 57% (radial) and 57% (ulnar) of cats. The absence of radial (p = 0.003) and ulnar (p = 0.007) MNCSs in dogs and ulnar MNCSs in cats (p = 0.02) was significantly associated to the amputation of the affected limb. The owners described signs of pain/discomfort in 73% of dogs and 56% of cats. This is the first report suggesting that neuropathic pain/discomfort should be adequately considered in order to improve the QoL.

Sonographic Pearls for Imaging the Brachial Plexus and Its Pathologies

The brachial plexus (BP) is a complicated neural network, which may be affected by trauma, irradiation, neoplasm, infection, and autoimmune inflammatory diseases. Magnetic Resonance Imaging is the preferred diagnostic modality; however, it has the limitations of high cost and lack of portability. High-resolution ultrasound has recently emerged as an unparalleled diagnostic tool for diagnosing postganglionic lesions of the BP. Existing literature describes the technical skills needed for prompt ultrasound imaging and guided injections for the BP. However, it remains particularly challenging for beginners to navigate easily while scanning its different parts. To address this, we share several “clinical pearls” for the sonographic examination of the BP as well as its common pathologies.

Pseudomeningocele From Brachial Plexus Root Avulsion

We report a case of a 42-year-old male involved in a motor vehicle accident. Initial MRI revealed T2 hypo-intensity of the anterior cord at the C6 level of the cervical spine which raised significant discussions within the neurosurgical, radiology and ICU departments at our institution. After careful review of images and patient’s clinical examination we suspected root avulsion of the brachial plexus. Subsequent MRI brachial plexus showed a large axillary pseudomeningocele originating from the C5-T2 nerve roots. Our team concluded the patient suffered a complete brachial plexus injury from right lateral hyperflexion as extrapolated from his injuries. The aim of this report is to highlight the uncommon condition and report of key clinical findings and management strategies.