The comparison of electrophysiologic findings of traumatic brachial plexopathies in a tertiary care center

Ultrasound of peripheral nerve injury

Nerve injury in children is important to recognize early given the greater chance for recovery. Both children and adults have better outcomes the sooner nerve injuries are recognized and repaired. Children have even better functional results after surgical repair, thought to be related to their neural plasticity. Ultrasound is a powerful diagnostic tool for grading and mapping peripheral nerve injury and is complementary to electromyography and nerve conduction studies. Nerve injuries can be classified into low and high grade with ultrasound adding essential prognostic information and aiding in patient management. High-grade nerve injuries likely require surgical intervention. This article will review nerve anatomy and injury grading systems that radiologists can learn quickly in order to accurately communicate with their clinical partners. A practical approach to describe the sonographic appearance of nerve injury will be discussed. This article will show radiologists how the added value of ultrasound for peripheral nerve injury can directly affect clinical management.

Nerve pathology and neuropathic pain after whiplash injury: a systematic review and meta-analysis

ABSTRACT

There is no clear understanding of the mechanisms causing persistent pain in patients with whiplash-associated disorder (WAD). The aim of this systematic review was to assess the evidence for nerve pathology and neuropathic pain in patients with WAD. EMBASE, PubMed, CINAHL (EBSCO), and MEDLINE were searched from inception to September 1, 2020. Study quality and risk of bias were assessed using the Newcastle-Ottawa Quality Assessment Scales. Fifty-four studies reporting on 390,644 patients and 918 controls were included. Clinical questionnaires suggested symptoms of predominant neuropathic characteristic in 34% of patients (range 25%-75%). The mean prevalence of nerve pathology detected with neurological examination was 13% (0%-100%) and 32% (10%-100%) with electrodiagnostic testing. Patients independent of WAD severity (Quebec Task Force grades I-IV) demonstrated significantly impaired sensory detection thresholds of the index finger compared with controls, including mechanical (SMD 0.65 [0.30; 1.00] P < 0.005), current (SMD 0.82 [0.25; 1.39] P = 0.0165), cold (SMD -0.43 [-0.73; -0.13] P = 0.0204), and warm detection (SMD 0.84 [0.25; 1.42] P = 0.0200). Patients with WAD had significantly heightened nerve mechanosensitivity compared with controls on median nerve pressure pain thresholds (SMD -1.10 [-1.50; -0.70], P < 0.0001) and neurodynamic tests (SMD 1.68 [0.92; 2.44], P = 0.0004). Similar sensory dysfunction and nerve mechanosensitivity was seen in WAD grade II, which contradicts its traditional definition of absent nerve involvement. Our findings strongly suggest a subset of patients with WAD demonstrate signs of peripheral nerve pathology and neuropathic pain. Although there was heterogeneity among some studies, typical WAD classifications may need to be reconsidered and include detailed clinical assessments for nerve integrity.

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.

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.

Traumatic brachial plexus injury: electrodiagnostic findings from 111 patients in a tertiary care hospital in India

OBJECTIVE

The study aims to characterise the electrodiagnostic findings of patients with traumatic brachial plexus injuries (BPIs) in India and to analyse the association between aetiologies and levels of injuries.

METHODS

A total of 111 consecutive electrodiagnostic studies done between January 2009 and June 2011 on persons with traumatic BPI were retrospectively analysed.

SETTING

Electrodiagnostic Laboratory, Department of Physical Medicine and Rehabilitation in a tertiary care university teaching hospital in South India.

MAIN OUTCOME MEASURES

Nerve conduction velocities and electromyography (EMG) to locate the level of BPI, Dumitru and Wilbourne scale to assess the severity of BPI.

RESULTS

We studied 106 males and five females, ranging from 11 to 59 years of age. All but one had unilateral BPI. Motorcycle crashes were the most frequent cause (n=64, 58%). Isolated supraclavicular injury was found in 98 arms (88%) and infraclavicular injury in seven arms (6%). Root-level injuries were more common in motorcycle crashes and occupation-related trauma, while trunk-level injuries were more often found in automobile crashes, falls, bicycle-related trauma and penetrating wounds. Pan root (C5-T1) involvement was more common in the motorcycle trauma group (74%). There was no significant association between aetiologies and levels of BPIs. A total of 73 (65%) plexus injuries were of 'severe' category as per Dumitru and Wilbourn scale.

CONCLUSIONS

Motorcycle crash is the most common cause of traumatic BPIs. Supraclavicular injury is the rule in most cases. Proper attention needs to be given to differentiate the mild to moderate injuries from the severe injuries with EMG techniques since most of the cases are severe. There was no significant association found between aetiologies and levels of injury.

The efficacy of end-to-end and end-to-side nerve repair (neurorrhaphy) in the rat brachial plexus

Proximal nerve injury often requires nerve transfer to restore function. Here we evaluated the efficacy of end-to-end and end-to-side neurorrhaphy of rat musculocutaneous nerve, the recipient, to ulnar nerve, the donor. The donor was transected for end-to-end, while an epineurial window was exposed for end-to-side neurorrhaphy. Retrograde tracing showed that 70% donor motor and sensory neurons grew into the recipient 3 months following end-to-end neurorrhaphy compared to 40-50% at 6 months following end-to-side neurorrhaphy. In end-to-end neurorrhaphy, regenerating axons appeared as thick fibers which regained diameters comparable to those of controls in 3-4 months. However, end-to-side neurorrhaphy induced slow sprouting fibers of mostly thin collaterals that barely approached control diameters by 6 months. The motor end plates regained their control density at 4 months following end-to-end but remained low 6 months following end-to-side neurorrhaphy. The short-latency compound muscle action potential, typical of that of control, was readily restored following end-to-end neurorrhaphy. End-to-side neurorrhaphy had low amplitude and wide-ranging latency at 4 months and failed to regain control sizes by 6 months. Grooming test recovered successfully at 3 and 6 months following end-to-end and end-to-side neurorrhaphy, respectively, suggesting that powerful muscle was not required. In short, both neurorrhaphies resulted in functional recovery but end-to-end neurorrhaphy was quicker and better, albeit at the expense of donor function. End-to-side neurorrhaphy supplemented with factors to overcome the slow collateral sprouting and weak motor recovery may warrant further exploration.

Concordance and Discrepancy between Electrodiagnosis and Magnetic Resonance Imaging in Cervical Root Avulsion Injuries

To clarify the relationships between electromyography (EMG) and magnetic resonance imaging (MRI), we compared findings in 37 selected patients who presented with cervical root avulsion injuries. Nerve root repair with C4-T1 hemilaminectomy was subsequently performed on 19 patients. The agreement between the two evaluative modalities with complete or incomplete lesions of ventral root and pre- or postganglionic lesions of dorsal root was measured for each root level. Both with ventral and dorsal root evaluation, C6, C7, and C8 yielded high agreement values, ranging from 86% to 94%. C5 manifested the lowest agreement values: 54% on ventral root assessment. Additionally, EMG, in comparison with MRI, revealed a higher quantity of implicated injured components. MRI, in turn, detected more lesion components than surgical exploration alone achieved. The capability of EMG to recognize axonotmesis leads to the discrepant findings between the two modalities. The visualization of mild neurotmesis by MRI, which cannot be achieved by surgical inspection, results in divergent findings between the two modalities. Both EMG and the MRI play crucial roles in preoperative assessment, and they may complement each other.

Complete recovery of spinal cord injury without radiographic abnormality and traumatic brachial plexopathy in a young infant falling from a 30-feet-high window

The laxity and elasticity of the infant or child spine may predispose him to cervical spine injury without bony disruption. The term 'SCIWORA' syndrome (Spinal Cord Injury Without Radiographic Abnormalities) is commonly used to characterize this condition. We report a 14-month-old infant who fell from a fourth-story window, with delayed onset of SCIWORA and brachial plexopathy. The infant initially presented with complete limb paralysis, but had a full recovery 6 months later. In contrast to the classical grave prognosis of these two conditions, our case represents one of the few exceptions in the literature with excellent recovery. Corresponding to previous reports, we suggest that the initial normal appearance of the spinal cord and nerve roots on magnetic resonance image may serve as a good prognosticator, regardless of the severity of initial neuroelectrophysiological studies or clinical manifestations.