Diagnosis and surgery of brachial plexus injuries

Clinical Predictors of C5 Spinal Nerve Viability in Pan-Brachial Plexus Injuries

BACKGROUND

In pan-brachial plexus injury, distinguishing between preganglionic and postganglionic injuries is crucial to reconstructive planning. This study aimed to identify preoperative factors that would accurately predict a reconstructible C5 spinal nerve.

METHODS

Patients with pan-brachial plexus injury from a single institution between 2001 and 2018 were reviewed. Patient demographics, clinical examination, diagnostic imaging, and electrodiagnostic results were recorded. C5 viability was determined based on supraclavicular exploration and intraoperative electrophysiologic testing. Univariate analysis identified significant factors for regression analysis. A multivariable parsimonious model was created using stepwise high-performance logistic regression.

RESULTS

A total of 311 patients (mean age, 29.9 years; 46 women and 265 men; mean Injury Severity Score, 17.2) were included. A total of 134 patients (43%) had a viable C5 nerve, and 50 patients (12%) had a viable C6 nerve. Intact C5 spinal nerve on computed tomographic (CT) myelogram (OR, 5.4), positive Tinel test (OR, 2.6), muscle strength greater than or equal to 4 (according to the modified British Medical Research Council scale) for the rhomboid (OR, 1.3) or greater than or equal to 4 for the serratus anterior (OR, 1.4), and rhomboid needle electromyography (OR, 1.8) were predictive of having a viable C5 spinal nerve. The multivariable parsimonious stepwise model (area under the curve, 0.77) included four factors: positive Tinel test, intact C5 spinal nerve on CT myelogram, hemidiaphragmatic elevation, and midcervical paraspinal fibrillations.

CONCLUSIONS

In this cohort of pan-brachial plexus patients with major polytrauma, there was a 43% incidence of viable C5 spinal nerve. A positive Tinel test (OR, 2.1) and intact C5 spinal nerve on CT myelogram (OR, 4.9) predicted a viable C5 nerve. In contrast, hemidiaphragmatic elevation (OR, 3.1) and midcervical paraspinal fibrillations (OR, 2.92) predicted root avulsion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Rapid Detecting Brachial Plexus Injury by Point-of-Care Ultrasonography

Brachial plexus injury (BPI) is regarded as one of the most devastating injuries of the upper extremity. Brachial plexus neuropathy can have a high morbidity by seriously affecting the motor function and sensation of upper limbs with loss of activities of daily living. The use of computed tomography myelogram and/or magnetic resonance imaging (MRI) assessing brachial plexus offers valuable details including the location, morphology, and severity of preganglionic and postganglionic injuries during the preoperative period. High-field-strength MRI with specific coil and specialized MRI sequences might be not available in every emergency setting and is time-consuming. Point-of-care ultrasonography (POCUS) comes in handy and offers good image resolution of muscles and nerves that makes early detection of neuromuscular injury possible. Here, we present a case report of BPI that POCUS provides indirect evidence of cervical root injury and expedite time to MRI.

Diagnostic Function of 3-Tesla Magnetic Resonance Imaging for the Assessment of Brachial Plexus Injury

Background:

This study aimed to evaluate the diagnostic function of 3-Tesla (T) magnetic resonance imaging (MRI) during the assessment of brachial plexus injury (BPI), in comparison with intraoperative findings.

Methods:

A retrospective study was performed on 60 patients (47 men and 13 women), who had clinical manifestations of BPI, underwent 3T MRI of the brachial plexus, and were surgically treated at the Viet Duc and Vinmec Times City hospitals, in Hanoi, Vietnam, from March 2016 to December 2019. Preganglionic and postganglionic lesion features were identified on MRI. The diagnostic function of MRI features for the determination of BPI was evaluated and correlated with intraoperative findings.

Results:

The root avulsion and pseudomeningocele preganglionic injuries were observed in 57% and 43% of MRIs, respectively, and were commonly observed at the C7 and C8 roots. Nerve disruption and never edema were observed in 47.56% and 33.53% of MRIs, respectively, and were commonly observed at the C5 and C6 roots. The sensitivity, specificity, accuracy, positive prognostic value, and negative prognostic value of 3T MRI were 64.12%, 92.90%, 80.33%, 87.50%, and 76.96%, respectively, for the diagnosis of total avulsion, and 68.52%, 83.33%, 80.67%, 47.44%, and 92.34%, respectively, for the diagnosis of nerve disruption.

Conclusion:

MRI offers valuable details regarding the location, morphology, and severity of both preganglionic and postganglionic injuries during the preoperative diagnosis of BPI. However, this modality played a moderate diagnostic role. Therefore, 3T MRI should be used as a supplemental evaluation, coupled with clinical tests and electromyography, to determine the most appropriate treatment strategies for BPI patients.

The diagnostic accuracy of 1.5T magnetic resonance imaging for detecting root avulsions in traumatic adult brachial plexus injuries

Identification of root avulsions is of critical importance in traumatic brachial plexus injuries because it alters the reconstruction and prognosis. Pre-operative magnetic resonance imaging is gaining popularity, but there is limited and conflicting data on its diagnostic accuracy for root avulsion. This cohort study describes consecutive patients requiring brachial plexus exploration following trauma between 2008 and 2016. The index test was magnetic resonance imaging at 1.5 Tesla and the reference test was operative exploration of the supraclavicular plexus. Complete data from 29 males was available. The diagnostic accuracy of magnetic resonance imaging for root avulsion(s) of C5-T1 was 79%. The diagnostic accuracy of a pseudomeningocoele as a surrogate marker of root avulsion(s) of C5-T1 was 68%. We conclude that pseudomeningocoles were not a reliable sign of root avulsion and magnetic resonance imaging has modest diagnostic accuracy for root avulsions in the context of adult traumatic brachial plexus injuries.

LEVEL OF EVIDENCE

III.

Accuracy of MRI in diagnosing peripheral nerve disease: a systematic review of the literature

OBJECTIVE

MRI is increasingly being used to evaluate extracranial peripheral nerve disease in clinical practice. The objective of this study was to systematically review the accuracy of MRI in distinguishing normal from abnormal extracranial peripheral nerves.

CONCLUSION

There is significant heterogeneity between studies investigating the accuracy of MRI. Studies have shown that nerve T2-weighted or STIR hyperintensity, nerve enlargement, and nerve flattening are associated with peripheral nerve disease.

High-resolution ultrasonography for the diagnosis of brachial plexus root lesions

The aim of this study was to investigate the feasibility of using high-resolution ultrasonography in the diagnosis of brachial plexus (BP) root lesions. A prospective study of ultrasonographic evaluation of BP nerve roots was performed in 37 patients with BP root lesions (29 with root injuries, 8 with tumors). The pre-operative ultrasonographic findings were compared with the surgical and pathohistological findings. All C5-7 roots were detected by ultrasonography in all patients, whereas 92% (68/74) of C8 and 51% (38/74) of T1 nerve roots were visualized. Among 29 patients with BP root avulsion, partial injuries or totally interrupted BP roots were detected in all patients. Cystic masses and neuromas were detected in 16 and 23 patients, respectively. In 8 patients with BP root tumors, 8 hypo-echoic masses were detected inside or partly outside of intervertebral foramina connecting to nerve roots. Surgical exploration revealed that there were 57 BP root avulsions in 29 patients. However, 2 T1 nerve root avulsions had been missed by pre-operative ultrasonography. Pathohistology revealed that all 8 BP root tumors pre-operatively diagnosed by ultrasonography were schwannomas. High-resolution ultrasonography can provide a convenient and accurate imaging modality for quick diagnosis and location of BP root lesions.

The diagnostic value of CT myelography, MR myelography, and both in neonatal brachial plexus palsy

BACKGROUND AND PURPOSE

Although most infants with brachial plexus palsy recover function spontaneously, approximately 10-30% benefit from surgical treatment. Pre-operative screening for nerve root avulsions is helpful in planning reconstruction. Our aim was to compare the diagnostic value of CT myelography, MR myelography, and both against a surgical criterion standard for detection of complete nerve root avulsions in birth brachial plexus palsy.

MATERIALS AND METHODS

Nineteen patients who underwent a preoperative CT and/or MR myelography and subsequent brachial plexus exploration were included. Imaging studies were analyzed for the presence of abnormalities potentially predictive of nerve root avulsion. Findings of nerve root avulsion on surgical exploration were used as the criterion standard to assess the predictive value of imaging findings.

RESULTS

Ninety-five root levels were examined. When the presence of any pseudomeningocele was used as a predictor, the sensitivity was 0.73 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. When presence of pseudomeningocele with absent rootlets was used as the predictor, the sensitivity was 0.68 for CT and 0.68 for MR imaging and the specificity was 0.96 for CT and 0.97 for MR imaging. The use of both CT and MR imaging did not increase diagnostic accuracy. Rootlet findings in the absence of pseudomeningocele were not helpful in predicting complete nerve root avulsion.

CONCLUSIONS

Findings of CT and MR myelography were highly correlated. Given the advantages of MR myelography, it is now the single technique for preoperative evaluation of nerve root avulsion at our institution.

Challenging pain syndromes: Parsonage-Turner syndrome

Parsonage-Turner syndrome (PTS) is a rare disorder typically characterized by an abrupt onset of upper extremity pain followed by progressive neurologic deficits, including weakness, atrophy, and occasionally sensory abnormalities. The exact cause and pathophysiology of PTS are complex and incompletely understood. Autoimmune, genetic, infectious, and mechanical processes have all been implicated. No specific treatments have been proven to reduce neurologic impairment or improve the prognosis of PTS. Most patients with PTS are treated with a multidisciplinary approach that includes both physical therapy and pharmacologic treatment, often with multiple agents. Further research is needed.

Differential diagnosis between pre- and postganglionic adult traumatic brachial plexus lesions by ultrasonography

The goal of this study was to prospectively investigate the feasibility of preoperative ultrasonography evaluation in the differentiation between pre- and postganglionic traumatic brachial plexus lesions. Two expert radiologists employed ultrasonography to observe the morphology of the brachial plexus in 23 patients with suspected traumatic brachial plexus lesions and 40 healthy volunteers. The detection rate was 100% (126/126) for the C5 through C7 nerve roots and upper and middle trunks and three fascicles, 84% (106/126) for the C8 roots and the lower trunks and 64% (81/126) for T1 roots in all subjects. Surgical inspections found 58 lesions in 23 patients (40 preganglionic lesions and 18 postganglionic lesions). Ultrasonography detected most of the brachial plexus lesions (56/58) but misjudged two preganglionic and two postganglionic lesions. The rate of differentiation was 93% (52/56). This study demonstrated that ultrasonography is a useful but experience-dependent supplemental imaging technique for preoperative diagnosis of brachial plexus lesions and differentiation between pre- and postganglionic brachial plexus lesions.

Comparison of nerve transfers and nerve grafting for traumatic upper plexus palsy: a systematic review and analysis

BACKGROUND

In treating patients with brachial plexus injury, there are no comparative data on the outcomes of nerve grafts or nerve transfers for isolated upper trunk or C5-C6-C7 root injuries. The purpose of our study was to compare, with systematic review, the outcomes for modern intraplexal nerve transfers for shoulder and elbow function with autogenous nerve grafting for upper brachial plexus traumatic injuries.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies in which patients had surgery for traumatic upper brachial plexus palsy within one year of injury and with a minimum follow-up of twelve months. Strength and shoulder and elbow motion were assessed as outcome measures. The Fisher exact test and Mann-Whitney U test were used to compare outcomes, with an alpha level of 0.05.

RESULTS

Thirty-one studies met the inclusion criteria. Two hundred and forty-seven (83%) and 286 (96%) of 299 patients with nerve transfers achieved elbow flexion strength of grade M4 or greater and M3 or greater, respectively, compared with thirty-two (56%) and forty-seven (82%) of fifty-seven patients with nerve grafts (p < 0.05). Forty (74%) of fifty-four patients with dual nerve transfers for shoulder function had shoulder abduction strength of grade M4 or greater compared with twenty (35%) of fifty-seven patients with nerve transfer to a single nerve and thirteen (46%) of twenty-eight patients with nerve grafts (p < 0.05). The average shoulder abduction and external rotation was 122° (range, 45° to 170°) and 108° (range, 60° to 140°) after dual nerve transfers and 50° (range, 0° to 100°) and 45° (range, 0° to 140°) in patients with nerve transfers to a single nerve.

CONCLUSIONS

In patients with demonstrated complete traumatic upper brachial plexus injuries of C5-C6, the pooled international data strongly favors dual nerve transfer over traditional nerve grafting for restoration of improved shoulder and elbow function. These data may be helpful to surgeons considering intraoperative options, particularly in cases in which the native nerve root or trunk may appear less than optimal, or when long nerve grafts are contemplated.

High-resolution ultrasound of the supraclavicular brachial plexus—can it improve therapeutic decisions in patients with plexus trauma?

Patients with major traumatic brachial plexus lesions benefit from early surgery, but they are seldom isolated by today's diagnostic workup. Subjects with ambiguous findings after such workups usually undergo a trial of conservative treatment and those without improvement delayed surgery. Our study focuses on this problem. Hence, the purpose of this study was to evaluate the impact of high-resolution ultrasound (HR-US) on patient recruitment for non-delayed surgery. Twelve patients after blunt shoulder trauma and standardized HR-US assessment who underwent plexus surgery were included in this prospective observational study. Thereby, a total of 168 plexus elements were evaluated. All findings were compared to electrophysiological data if available and tested statistically against the gold-standard, i.e., surgical validation. Major plexus lesions were correctly detected by HR-US in nine patients (20 plexus elements). In two patients (five plexus elements), the lesion was underestimated by HR-US in relation to the gold standard (surgical inspection). Our analysis showed a high positive (1.0) and an acceptable negative predictive value (0.92) for the grading of traumatic plexus lesions with HR-US. Based on HR-US findings alone, 9 of 11 patients with objective major lesions would have undergone early surgery. In conclusion, HR-US proved a valuable tool for the triage of patients with traumatic lesions into surgical and non-surgical candidates.

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.

Sonography of Brachial Plexus Traction Injuries

OBJECTIVE

Our purpose was to evaluate the feasibility of sonography in identifying nerve abnormalities in patients with traction injury of the brachial plexus.

CONCLUSION

Sonography of the brachial plexus was technically feasible, although the entire brachial plexus could not be evaluated. Sonography appears to be a useful bedside imaging technique for assessing brachial plexus injury. The potential of sonography as a complementary diagnostic tool in the evaluation of these patients warrants further investigation.

Surgical repair of brachial plexus injury: a multinational survey of experienced peripheral nerve surgeons

Object. Brachial plexus injuries (BPIs) are often devastating events that lead to upper-extremity paralysis, rendering the limb a painful extraneous appendage. Fortunately, there are several nerve repair techniques that provide restoration of some function. Although there is general agreement in the medical community concerning which patients may benefit from surgical intervention, the actual repair technique for a given lesion is less clear. The authors sought to identify and better define areas of agreement and disagreement among experienced peripheral nerve surgeons as to the management of BPIs.

Methods. The authors developed a detailed survey in two parts: one part addressing general issues related to BPI and the other presenting four clinical cases. The survey was mailed to 126 experienced peripheral nerve physicians and 49 (39%) participated in the study. The respondents represent 22 different countries and multiple surgical subspecialties. They performed a mean of 33 brachial plexus reconstructions annually. Areas of significant disagreement included the timing and indications for surgical intervention in birth-related palsy, treatment of neuroma-in-continuity, the best transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for motor neurotization, and the use of distal or proximal coaptation during nerve transfer.

Conclusions. Experienced peripheral nerve surgeons disagree in important ways as to the management of BPI. The decisions made by the various treating physicians underscore the many areas of disagreement regarding the treatment of BPI, including the diagnostic approach to defining the injury, timing of and indications for surgical intervention in birth-related palsy, the treatment of neuroma-in-continuity, the choice of nerve transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for neurotization, and the use of distal or proximal coaptation during nerve transfer.

Surgical repair of brachial plexus injury: a multinational survey of experienced peripheral nerve surgeons

Background

Brachial plexus injuries (BPIs) are often devastating events that lead to upper-extremity paralysis, rendering it a painful extraneous appendage. Fortunately, there are several nerve repair techniques that provide restoration of some function. Although there is general agreement in the medical community concerning which patients may benefit from surgical intervention, the actual repair technique for a given lesion is less clear.

Object

The authors sought to identify and better define areas of agreement and disagreement among experienced peripheral nerve surgeons regarding the management of BPIs.

Methods

The authors developed a detailed survey in two parts: one part addressing general issues related to BPI and the other presenting four clinical cases. The survey was mailed to 126 experienced peripheral nerve physicians of whom 49 (39%) participated in the study. The respondents represented 22 countries and multiple surgical subspecialties. They performed a mean of 34 brachial plexus reconstructions annually. Areas of significant disagreement included the timing and indications for surgical intervention in birth-related palsy, management of neuroma-in-continuity, the best transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for motor neurotization, and the use of distal compared with proximal coaptation during nerve transfer.

Conclusions

Experienced peripheral nerve surgeons disagreed in important respects as to the management of BPI. The decisions made by the various treating physicians underscored the many areas of disagreement regarding the treatment of BPI including the diagnostic approach to defining the injury, timing of and indications for surgical intervention in birth-related palsy, management of neuroma-in-continuity, choice of nerve transfers to achieve elbow flexion and shoulder abduction, use of intra- or extraplexal donors for neurotization, and the use of distal or proximal coaptation during nerve transfer.

Macro- and Microanatomical Characterization of the Cat Brachial Plexus

The anatomy of the cat brachial plexus is poorly documented despite its importance for reparative surgery. The present work aims to study the anatomy of the brachial plexus of 20 European cats and to analyze the radicular constituents of 10 of them using histological techniques. The plexus radicular constitution is very homogeneous and is mainly composed of the ventral rami (also called ventral branches) arising from C6, C7, C8 and T1 spinal nerves. The fascicular and axonal structure is more variable. C8 is the ventral ramus that contains the largest number of axons (16,673 +/- 3,307), and is composed of 6.7 +/- 3.5 fascicles. The radial nerve is the peripheral nerve that contains the largest number of axons (11,245 +/- 2,217), and is composed of 7.3 +/- 3.8 fascicles. The number of nervous fibers does not differ proportionally to the weight of the cat, or between the right or the left side. Our data could help neurotization and entubulation repair after brachial plexus injury.

Immunohistochemical characterization of axonal sprouting and reactive tissue changes after long-term implantation of a polyimide sieve electrode to the transected adult rat sciatic nerve

The development of artificial microstructures suited for interfacing of peripheral nerves is not only relevant for basic neurophysiological research but also for future prosthetic approaches. Aim of the present study was to provide a detailed analysis of axonal sprouting and reactive tissue changes after implantation of a flexible sieve electrode to the proximal stump of the adult rat sciatic nerve. We report here that massive neurite growth after implantation, steadily increasing over a period of 11 months, was observed. Parallel to this increase was the expression of myelin markers like Po, whereas non-myelin-forming Schwann cells did not change. Compared to five weeks post-implantation. where both Schwann-cell phenotypes were intermingled with each other, non-myelin-forming Schwann cells occupied a peripheral position in each microfascicle after 11 months. After an initial increase, hematogenous macrophages were down-regulated in number but maintained close contact with the implant. However, at no time were signs of its degradation observed. It is concluded that the introduced flexible polyimide electrode is suitable for contacting peripheral nerves since it permits substantial neurite growth and offers excellent long-term stability.

Approaches permitting and enhancing motoneuron regeneration after spinal cord, ventral root, plexus and peripheral nerve injuries

The motoneuron has a strong ability to regenerate after injury. However, the problems of nerve cell survival after a proximal axotomy, difficulty in axonal elongation after intraspinal lesion and the lack of target specificity during nerve fibre regrowth interfere with a good functional restitution. Current research has addressed these impediments. New approaches for the management of complicated as well as intraspinal lesions and peripheral nerve trunk injuries are described.

The surgical treatment of brachial plexus injuries in adults

Posttraumatic brachial plexus palsy is a severe injury primarily affecting young individuals at the prime of their life. The devastating neurological dysfunction inflicted in those patients is usually lifelong and creates significant socioeconomic issues. During the past 30 years, the surgical repair of these injuries has become increasingly feasible. At many centers around the world, leading surgeons have introduced new microsurgical techniques and reported a variety of different philosophies for the reconstruction of the plexus. Microneurolysis, nerve grafting, recruitment of intraplexus and extraplexus donors, and local and free-muscle transfers are used to achieve optimal outcomes. However, there is yet no consensus on the priorities and final goals of reconstruction among the various centers.