Predictive value of computed tomographic myelography in obstetrical brachial plexus palsy

Electrodiagnostic studies and new diagnostic modalities for evaluation of peripheral nerve disorders

Electrodiagnostic studies (EDx) are frequently performed in the diagnostic evaluation of peripheral nerve disorders. There is increasing interest in the use of newer, alternative diagnostic modalities, in particular imaging, either to complement or replace established EDx protocols. However, the evidence to support this approach has not been expansively reviewed. In this paper, diagnostic performance data from studies of EDx and other diagnostic modalities in common peripheral nerve disorders have been analyzed and described, with a focus on radiculopathy, plexopathy, compressive neuropathies, and the important neuropathy subtypes of Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), vasculitic neuropathy and diabetic neuropathy. Overall EDx retains its place as a primary diagnostic modality in the evaluated peripheral nerve disorders. Magnetic resonance imaging and ultrasound have developed important complementary diagnostic roles in compressive and traumatic neuropathies and atypical CIDP, but their value is more limited in other neuropathy subtypes. Identification of hourglass constriction in nerves of patients with neuralgic amyotrophy may have therapeutic implications. Investigation of radiculopathy is confounded by poor correlation between clinical features and imaging findings and the lack of a diagnostic gold standard. There is a need to enhance the literature on the utility of these newer diagnostic modalities.

Evaluation of Infantile Brachial Plexopathy Using 3T MRI and High-Resolution Ultrasound: Experience From a Tertiary Care Centre

BACKGROUND

Currently, clinical assessment is the main tool for the evaluation of brachial plexus injury, complemented by electrophysiologic studies (EPS), and imaging studies whenever available. Imaging plays an important role as it enables the differentiation of pre-ganglionic and postganglionic injuries, and adds objectivity to presurgical evaluation.

OBJECTIVES

The primary objective was to evaluate the utility of magnetic resonance imaging (MRI) and high-resolution ultrasonography (USG) in the localization and characterization of brachial plexus injury in infants.

MATERIALS AND METHODS

In this prospective study, 34 infants with signs and symptoms of brachial plexus injury were evaluated by clinical examination, EPS, MRI, and USG. Imaging findings were correlated with intraoperative findings in infants who underwent surgical management. The association between EPS and MRI findings, and USG and MRI findings were assessed using Fisher's exact test. Semi-quantitative subjective analysis of various MRI sequences was done as well.

RESULTS

The most common findings of preganglionic injury and postganglionic injury, in our study, were pseudomeningocele and nerve thickening, respectively. MRI detection of injuries had a significant association with EPS findings. All MRI-detected injuries had a muscle power of grade 3 or less. muscle. Three-dimensional (3D) short tau inversion recovery (STIR) sequence was found to be superior for detecting postganglionic injuries (P < 0.05).

CONCLUSION

Imaging studies enable localization of the site of injury, determining the extent, and nature/morphology of injury. The gamut of findings obtained from MRI is far wider compared to that from USG. USG can be used as the first-line screening investigation.

Management of Brachial Plexus Birth Injury: The SickKids Experience

This article describes the approach utilized by the multidisciplinary team at Sick Kids Hospital to evaluate and treat patients with brachial plexus birth injury (BPBI). This approach has been informed by more than 30 years of experience treating over 1,800 patients with BPBI and continues to evolve over time. The objective of this article is to provide readers with a practical overview of the Sick Kids approach to the management of infants with BPBI.

Radiographic imaging modalities for perinatal brachial plexus palsy: a systematic review

PURPOSE

Perinatal brachial plexus palsy (PBPP) has a wide spectrum of clinical symptoms that can range from incomplete paresis of the affected extremity to flaccid arm paralysis. Although there is a high rate of spontaneous recovery within the first two years of life, it remains challenging to determine which patients will benefit most from surgical intervention. The diagnostic and predictive use of various imaging modalities has been described in the literature, but there is little consensus on approach or algorithm. The anatomic, pathophysiological, and neurodevelopmental characteristics of the neonatal and infant patient population affected by PBPP necessitate thoughtful consideration prior to selecting an imaging modality.

METHODS

A systematic review was conducted using six databases. Two reviewers independently screened articles published through October 2021.

RESULTS

Literature search produced 10,329 publications, and 22 articles were included in the final analysis. These studies included 479 patients. Mean age at time of imaging ranged from 2.1 to 12.8 months and investigated imaging modalities included MRI (18 studies), ultrasound (4 studies), CT myelography (4 studies), and X-ray myelography (1 study). Imaging outcomes were compared against surgical findings (16 studies) or clinical examination (6 studies), and 87.5% of patients underwent surgery.

CONCLUSION

This systematic review addresses the relative strengths and challenges of common radiologic imaging options. MRI is the most sensitive and specific for identifying preganglionic nerve injuries such as pseudomeningoceles and rootlet avulsion, the latter of which has the poorest prognosis in this patient population and often dictates the need for surgical intervention.

Surgical Reconstruction of Isolated Upper Trunk Brachial Plexus Birth Injuries in the Presence of an Avulsed C5 or C6 Nerve Root

BACKGROUND

Avulsion of either the C5 or C6 root with intact middle and lower trunks in brachial plexus birth injury is rare. In these cases, only 1 proximal root is available for intraplexal reconstruction. The purpose of the present study was to determine the outcomes of these patients when single-root reconstruction was balanced across the anterior and posterior elements of the upper trunk.

METHODS

We performed a retrospective cohort study of prospectively collected data for patients with brachial plexus birth injury who underwent primary nerve reconstruction between 1993 and 2014. Patients were included who had isolated upper-trunk injuries with intact middle and lower trunks. The study group had avulsion of either the C5 or C6 root. The control group had neuroma-in-continuity or ruptures of the upper trunk. Outcomes were assessed with use of the Active Movement Scale and the Brachial Plexus Outcome Measure. The Wilcoxon signed-rank test was utilized to evaluate changes across treatment.

RESULTS

Ten patients with brachial plexus birth injury were included in the avulsion cohort. Surgical reconstruction entailed neuroma resection and nerve grafting from the single available root balanced across all distal targets with or without spinal accessory-to-suprascapular nerve transfer. Significant improvements were observed across treatment for both the avulsion and control groups in terms of shoulder abduction, shoulder flexion, external rotation, elbow flexion, and supination. At a mean follow-up of 54.5 ± 8.8 months, patients in the avulsion group achieved Active Movement Scale scores of 6.8 ± 0.4 for elbow flexion and 6.5 ± 0.9 for shoulder flexion and abduction, with lesser recovery observed in external rotation (3.3 ± 2.8). All patients available for Brachial Plexus Outcome Measure assessments demonstrated functional movement.

CONCLUSIONS

In the setting of avulsion of 1 upper-trunk root, nerve reconstruction by grafting of the upper trunk from the other upper-trunk root provides improved movement, high Active Movement Scale scores, and satisfactory function according to the Brachial Plexus Outcome Measure. These data provide support for a strategy that ensures the entire upper trunk is adequately reconstructed in the setting of upper-trunk lesions.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

MRI evaluation of nerve root avulsion in neonatal brachial plexus palsy: understanding the presence of isolated dorsal/ventral rootlet disruption

OBJECTIVE

The evaluation, treatment, and prognosis of neonatal brachial plexus palsy (NBPP) continues to have many areas of debate, including the use of ancillary testing. Given the continued improvement in imaging, it is important to revisit its utility. Nerve root avulsions have historically been identified by the presence of pseudomeningoceles or visible ruptures. This "all-or-none" definition of nerve root avulsions has many implications for the understanding and management of NBPP, especially as characterization of the proximal nerve root as a potential donor remains critical. This study examined the ability of high-resolution MRI to more specifically define the anatomy of nerve root avulsions by individually examining the ventral and dorsal rootlets as they exit the spinal cord.

METHODS

This is a retrospective review of patients who had undergone brachial plexus protocol MRI for clinical evaluation of NBPP at a single institution. Each MR image was independently reviewed by a board-certified neuroradiologist, who was blinded to both established diagnosis/surgical findings and laterality. Each dorsal and ventral nerve rootlet bilaterally from C5 to T1 was evaluated from the spinal cord to its exit in the neuroforamen. Each rootlet was classified as avulsed, intact, or undeterminable.

RESULTS

Sixty infants underwent brachial plexus protocol MRI from 2010 to 2018. All infants were included in this study. Six hundred individual rootlets were analyzed. There were 49 avulsed nerve rootlets in this cohort. Twenty-nine (59%) combined dorsal/ventral avulsions involved both the ventral and dorsal rootlets, and 20 (41%) were either isolated ventral or isolated dorsal rootlet avulsions. Of the isolated avulsion injuries, 13 (65%) were dorsal only, meaning that the motor rootlets were intact.

CONCLUSIONS

A closer look at nerve root avulsions with MRI demonstrates a significant prevalence (approximately 41%) of isolated dorsal or ventral nerve rootlet disruptions. This finding implies that nerve roots previously labeled as "avulsed" but with only isolated dorsal (sensory) rootlet avulsion can yet provide donor fascicles in reconstruction strategies. A majority (99%) of the rootlets can be clearly visualized with MRI. These findings may significantly impact the clinical understanding of neonatal brachial plexus injury and its treatment.

Surgical Reconstruction of Isolated Upper Trunk Brachial Plexus Birth Injuries in the Presence of an Avulsed C5 or C6 Nerve Root

BACKGROUND

Avulsion of either the C5 or C6 root with intact middle and lower trunks in brachial plexus birth injury is rare. In these cases, only 1 proximal root is available for intraplexal reconstruction. The purpose of the present study was to determine the outcomes of these patients when single-root reconstruction was balanced across the anterior and posterior elements of the upper trunk.

METHODS

We performed a retrospective cohort study of prospectively collected data for patients with brachial plexus birth injury who underwent primary nerve reconstruction between 1993 and 2014. Patients were included who had isolated upper-trunk injuries with intact middle and lower trunks. The study group had avulsion of either the C5 or C6 root. The control group had neuroma-in-continuity or ruptures of the upper trunk. Outcomes were assessed with use of the Active Movement Scale and the Brachial Plexus Outcome Measure. The Wilcoxon signed-rank test was utilized to evaluate changes across treatment.

RESULTS

Ten patients with brachial plexus birth injury were included in the avulsion cohort. Surgical reconstruction entailed neuroma resection and nerve grafting from the single available root balanced across all distal targets with or without spinal accessory-to-suprascapular nerve transfer. Significant improvements were observed across treatment for both the avulsion and control groups in terms of shoulder abduction, shoulder flexion, external rotation, elbow flexion, and supination. At a mean follow-up of 54.5 ± 8.8 months, patients in the avulsion group achieved Active Movement Scale scores of 6.8 ± 0.4 for elbow flexion and 6.5 ± 0.9 for shoulder flexion and abduction, with lesser recovery observed in external rotation (3.3 ± 2.8). All patients available for Brachial Plexus Outcome Measure assessments demonstrated functional movement.

CONCLUSIONS

In the setting of avulsion of 1 upper-trunk root, nerve reconstruction by grafting of the upper trunk from the other upper-trunk root provides improved movement, high Active Movement Scale scores, and satisfactory function according to the Brachial Plexus Outcome Measure. These data provide support for a strategy that ensures the entire upper trunk is adequately reconstructed in the setting of upper-trunk lesions.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparative accuracies of electrodiagnostic and imaging studies in neonatal brachial plexus palsy

OBJECTIVEThe incorporation of ancillary testing in the preoperative setting for patients with neonatal brachial plexus palsy (NBPP) remains controversial, but the recommendation for early nerve reconstruction when a baby has a preganglionic lesion at the lower nerve roots is generally accepted. At some specialty centers, nerve surgeons use preoperative electrodiagnostic testing (EDX) and imaging to aid in lesion localization and the preoperative planning of the nerve reconstruction. EDX and imaging have been evaluated for their abilities to detect pre- and postganglionic lesions, but their accuracies have never been compared directly in the same set of patients. The aim of the present study was to evaluate the accuracy of imaging and EDX in an NBPP population.METHODSA retrospective review was conducted of 54 patients with operative NBPP seen between 2007 and 2017. The patients underwent EDX and imaging: EDX was performed, and the results were reviewed by board-certified electrodiagnosticians, and imaging was reviewed by board-certified neuroradiologists. The gold standard was considered to be the findings at surgical exploration. Descriptive and analytical statistics were utilized to compare the accuracies of imaging and EDX.RESULTSThe mean age at surgery was 6.94 mos (± 4 mos). Fifteen patients (28%) were Narakas grade I-II, and 39 (72%) were Narakas grade III-IV. For all nerve roots, the overall accuracy of detecting preganglionic lesions was 74% for EDX and 69% for imaging. The overall sensitivity of detecting preganglionic lesions by EDX was 31%, but the specificity was 90%. The overall sensitivity of detecting preganglionic lesions by imaging was 66%, and the overall specificity was 70%. However, at C8, EDX was 37.5% sensitive and 87.5% specific, whereas imaging was 67.7% sensitive but only 29.4% specific.CONCLUSIONSEDX outperformed imaging with regard to specificity and accuracy of identifying preganglionic injuries. This finding is especially relevant in the lower nerve roots, given that lower plexus preganglionic lesions are an accepted indication for early intervention.

An Update on the Management of Neonatal Brachial Plexus Palsy-Replacing Old Paradigms: A Review

IMPORTANCE

Neonatal brachial plexus palsy (NBPP) can result in persistent deficits for those who develop it. Advances in surgical technique have resulted in the availability of safe, reliable options for treatment. Prevailing paradigms include, "all neonatal brachial plexus palsy recovers," "wait a year to see if recovery occurs," and "don't move the arm." Practicing by these principles places these patients at a disadvantage. Thus, the importance of this review is to provide an update on the management of NBPP to replace old beliefs with new paradigms.

OBSERVATIONS

Changes within denervated muscle begin at the moment of injury, but without reinnervation become irreversible 18 to 24 months following denervation. These time-sensitive, irreversible changes are the scientific basis for the recommendations herein for the early management of NBPP and put into question the old paradigms. Early referral has become increasingly important because improved outcomes can be achieved using new management algorithms that allow surgery to be offered to patients unlikely to recover sufficiently with conservative management. Mounting evidence supports improved outcomes for appropriately selected patients with surgical management compared with natural history. Primary nerve surgery options now include nerve graft repair and nerve transfer. Specific indications continue to be elucidated, but both techniques offer a significant chance of restoration of function.

CONCLUSIONS AND RELEVANCE

Mounting data support both the safety and effectiveness of surgery for patients with persistent NBPP. Despite this support, primary nerve surgery for NBPP continues to be underused. Surgery is but one part of the multidisciplinary care of NBPP. Early referral and implementation of multidisciplinary strategies give these children the best chance of functional recovery. Primary care physicians, nerve surgeons, physiatrists, and occupational and physical therapists must partner to continue to modify current treatment paradigms to provide improved quality care to neonates and children affected by NBPP.

Neonatal Magnetic Resonance Imaging Without Sedation Correlates With Injury Severity in Brachial Plexus Birth Palsy

PURPOSE

Which infants with brachial plexus birth palsy (BPBP) should undergo microsurgical plexus reconstruction remains controversial. The current gold standard for the decision for plexus reconstruction is serial clinical examinations, but this approach obviates the possibility of early surgical treatment. We hypothesize that a new technique using 3-dimensional volumetric proton density magnetic resonance imaging (MRI) without sedation can evaluate the severity of BPBP injury earlier than serial clinical examinations.

METHODS

Infants were prospectively enrolled prior to 12 weeks of age and imaged using 3 Tesla MRI without sedation. Clinical scores were collected at all visits. The imaging findings were graded based on the number of injured levels and the severity of each injury, and a radiological score was calculated. All infants were followed at least until the decision for surgery was made based on clinical examination.

RESULTS

Nine infants completed the MRI scan and clinical follow-up. The average Toronto score at presentation was 4.4 out of 10 (range, 0-8.2); the average Active Movement Scale score was 50 out of 105 (range, 0-86). Four infants required surgery: 2 because of a flail limb and Horner syndrome and 2 owing to failure to recover antigravity elbow flexion by age 6 months. Radiological scores ranged from 0 to 18 out of a maximum score of 25. The average radiological score for those infants who required surgery was 12 (range, 6.5-18), whereas the average score for infants who did not require surgery was 3.5 (range, 0-8).

CONCLUSIONS

Three-dimensional proton density MRI can evaluate spinal nerve roots in infants without the need for radiation, contrast agents, or sedation. These data suggest that MRI can help determine the severity of injury earlier than clinical examination in infants with BPBP, although further study of a larger sample of infants with varying severity of disease is necessary.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Non-Sedated Rapid Volumetric Proton Density MRI Predicts Neonatal Brachial Plexus Birth Palsy Functional Outcome

BACKGROUND AND PURPOSE

The current prognostic biomarker of functional outcome in brachial plexus birth palsy is serial clinical examination throughout the first 6 months of age. This can delay surgical treatment and prolong parental anxiety in neonates who will recover spontaneously. A potentially superior biomarker is a volumetric proton density MRI performed at clinical presentation and within the first 12 weeks of life, providing a high spatial and contrast resolution examination in 4 minutes.

METHODS

Nine neonates ranging in age from 4 to 9 weeks who presented with brachial plexus birth palsy were enrolled. All subjects underwent non-sedated 3 Tesla MRI with Cube Proton Density MRI sequence at the same time as their initial clinical visit. Serial clinical examinations were conducted at routine 4 week intervals and the functional performance scores were recorded. MRI findings were divided into pre-ganglionic and post-ganglionic injuries and a radiological scoring system (Shriners Radiological Score) was developed for this study.

RESULTS

Proton Density MRI was able to differentiate between pre-ganglionic and post-ganglionic injuries. Radiological scores (Shriners Radiological Score) correlated better with functional performance at 6 months of age (P = .022) than the initial clinical examinations (Active Movement Scale P = .213 and Toronto P = .320).

CONCLUSIONS

Rapid non-sedated volumetric Cube Proton Density MRI protocol performed at initial clinical presentation can accurately grade severity of brachial plexus birth palsy injury and predict functional performance at 6 months of age.

Nerve Transfers in Birth Related Brachial Plexus Injuries: Where Do We Stand?

This article reviews the assessment and management of obstetrical brachial plexus palsy. The potential role of distal nerve transfers in the treatment of infants with Erb's palsy is discussed. Current evidence for motor outcomes after traditional reconstruction via interpositional nerve grafting and extraplexal nerve transfers is reviewed and compared with the recent literature on intraplexal distal nerve transfers in obstetrical brachial plexus injury.

Neonatal brachial plexus palsy: a permanent challenge

Neonatal brachial plexus palsy (NBPP) has an incidence of 1.5 cases per 1000 live births and it has not declined despite recent advances in obstetrics. Most patients will recover spontaneously, but some will remain severely handicapped. Rehabilitation is important in most cases and brachial plexus surgery can improve the functional outcome of selected patients. This review highlights the current management of infants with NBPP, including conservative and operative approaches.

International Federation of Societies for Surgery of the Hand Committee report: the role of nerve transfers in the treatment of neonatal brachial plexus palsy

Nerve transfers have gained popularity in the treatment of adult brachial plexus palsy; however, their role in the treatment of neonatal brachial plexus palsy (NBPP) remains unclear. Brachial plexus palsies in infants differ greatly from those in adults in the patterns of injury, potential for recovery, and influences of growth and development. This International Federation of Societies for Surgery of the Hand committee report on NBPP is based upon review of the current literature. We found no direct comparisons of nerve grafting to nerve transfer for primary reconstruction of NBPP. Although the results contained in individual reports that use each strategy for treatment of Erb palsy are similar, comparison of nerve transfer to nerve grafting is limited by inconsistencies in outcomes reported, by multiple confounding factors, and by small numbers of patients. Although the role of nerve transfers for primary reconstruction remains to be defined, nerve transfers have been found to be effective and useful in specific clinical circumstances including late presentation, isolated deficits, failed primary reconstruction, and multiple nerve root avulsions. In the case of NBPP more severe than Erb palsy, nerve transfers alone are inadequate to address all of the deficits and should only be considered as adjuncts if maximal re-innervation is to be achieved. Surgeons who commit to care of infants with NBPP need to avoid an over-reliance on nerve transfers and should also have the capability and inclination for brachial plexus exploration and nerve graft reconstruction.

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.

Diagnosis of brachial and lumbosacral plexus lesions

To most doctors, brachial and lumbosacral plexopathies are known as difficult disorders, because of their complicated anatomy and relatively rare occurrence. Both the brachial, lumbar, and sacral plexuses are extensive PNS structures stretching from the neck to axillary region and running in the paraspinal lumbar and pelvic region, containing 100000-200000 axons with 12-15 major terminal branches supplying almost 50 muscles in each limb. The most difficult part in diagnosing a plexopathy is probably that it requires an adequate amount of clinical suspicion combined with a thorough anatomical knowledge of the PNS and a meticulous clinical examination. Once a set of symptoms is recognized as a plexopathy the patients' history and course of the disorder will often greatly limit the differential diagnosis. The most common cause of brachial plexopathy is probably neuralgic amyotrophy and the most common cause of lumbosacral plexopathy is diabetic amyotrophy. Traumatic and malignant lesions are fortunately rarer but just as devastating. This chapter provides an overview of both common and rarer brachial and lumbosacral plexus disorders, focusing on clinical examination, the use of additional investigative techniques, prognosis, and treatment.

Assessment of the usefulness of X-ray myelography and magnetic resonance myelography, performed with an open low-field device, in diagnosing perinatal preganglionic injuries of the brachial plexus

INTRODUCTION

The goal is to assess the usefulness of diagnostic imaging in diagnosing perinatal preganglionic injuries of the brachial plexus.

MATERIAL AND METHODS

The clinical material included 40 children of both genders, aged 2 to 35 months. The authors analysed the results of diagnostic imaging examinations (myelography in 20 cases and magnetic resonance [MR] myelography in 20 cases), intraoperative view and clinical course.

RESULTS

In 13 out of 40 (32.5%) examined children, no evidence of avulsion of the roots of the spinal nerves was found either by diagnostic imaging or during the surgery. In 3 cases (7.5%) with avulsed roots of the spinal nerves, the diagnostic imaging and intraoperative appearance were in agreement. Total agreement of the diagnostic imaging and intraoperative view was found in 40% of cases. In 9 patients (22.5%) suspected avulsion of roots of the spinal nerves was not confirmed during the surgery. However, the further clinical course of the disease in these cases indicated high probability of avulsion of roots without their pull-out from the intervertebral foramens. In the remaining cases, the findings were as follows: false positive results - 7 (17.5%), false negative results - 1 (2.5%), results underestimating injury - 3 (7.5%), results overestimating injury - 2 (5%).

CONCLUSIONS

It was determined that the usefulness of pre-operative diagnostic imaging is limited. Due to the risk of occurrence of false positive and false negative results, final decisions concerning selection of the surgical technique must be based on the analysis of the intraoperative view and preoperative clinical symptoms.

Utility of electrodiagnostic testing and computed tomography myelography in the preoperative evaluation of neonatal brachial plexus palsy

OBJECT

The rate of neonatal brachial plexus palsy (NBPP) remains 0.4%-4% despite improvements in perinatal care. Among affected children, the extent of brachial plexus palsy differs greatly, as does the prognosis. Controversial elements in management include indications and timing of nerve repair as well as type of reconstruction in patients in whom function will ultimately not be recovered without surgical intervention. Differentiating preganglionic (avulsion) from postganglionic (rupture) lesions is critical because preganglionic lesions cannot spontaneously recover motor function. Distinguishing between these lesions at initial presentation based on clinical examination alone can be difficult in infants. The purpose of the present study was to determine the sensitivity of preoperative electrodiagnostic studies (EDSs) and CT myelography (CTM) in determining the presence of nerve root rupture and avulsions in infants with NBPP.

METHODS

After receiving institutional review board approval, the authors conducted a retrospective review of patients referred to the Neonatal Brachial Plexus Program between 2007 and 2010. Inclusion criteria included children who underwent brachial plexus exploration following preoperative EDSs and CTM. The CTM scans were interpreted by a staff neuroradiologist, EDSs were conducted by a single physiatrist, and intraoperative findings were recorded by the operating neurosurgeon. The findings from the preoperative EDSs and CTM were then compared with intraoperative findings. The sensitivities and 95% confidence intervals were determined to evaluate performance accuracy of each preoperative measure.

RESULTS

Twenty-one patients (8 male amd 13 female) met inclusion criteria for this study. The sensitivity of EDSs and CTM for detecting a postganglionic rupture was 92.8% (CI 0.841-0.969) and 58.3% (CI 0.420-0.729), respectively. The sensitivity for EDSs and CTM for preganglionic nerve root avulsion was 27.8% (CI 0.125-0.509) and 72.2% (CI 0.491-0.875), respectively. In cases in which both CTM and EDSs gave concordant results, the sensitivity for both modalities combined was 50.0% (CI 0.237-0.763) for avulsion and 80.8% (CI 0.621-0.915) for rupture. Overall, EDSs were most useful in identifying ruptures, particularly in the upper plexus, whereas CTM was most sensitive in identifying avulsions in the lower plexus.

CONCLUSIONS

Knowledge of the spinal nerve integrity is critical for early management of patients with NBPP. Surgical management, in the form of nerve repair/reconstruction, and optimal prognostication of NBPP depend on the accurate diagnosis of the level and type of lesion. Both EDSs and CTM scans must always be interpreted in the context of a comprehensive evaluation of the patient. They provide supplemental information (in addition to the physical examination) for early detection of nerve root rupture and avulsion injuries, aiding surgical decision making and preoperative planning for NBPP. Continued advances in imaging, EDSs, and microsurgical nerve repair techniques will allow surgeons to achieve greater success for functional recovery in management of NBPP.

Perinatal brachial plexus palsy

BACKGROUND

Perinatal brachial plexus palsy (PBPP) is a flaccid paralysis of the arm at birth that affects different nerves of the brachial plexus supplied by C5 to T1 in 0.42 to 5.1 infants per 1000 live births.

OBJECTIVES

To identify antenatal factors associated with PBPP and possible preventive measures, and to review the natural history as compared with the outcome after primary or secondary surgical interventions.

METHODS

A literature search on randomized controlled trials, systematic reviews and meta-analyses on the prevention and treatment of PBPP was performed. EMBASE, Medline, CINAHL and the Cochrane Library were searched until June 2005. Key words for searches included 'brachial plexus', 'brachial plexus neuropathy', 'brachial plexus injury', 'birth injury' and 'paralysis, obstetric'.

RESULTS

There were no prospective studies on the cause or prevention of PBPP. Whereas birth trauma is said to be the most common cause, there is some evidence that PBPP may occur before delivery. Shoulder dystocia and PBPP are largely unpredictable, although associations of PBPP with shoulder dystocia, infants who are large for gestational age, maternal diabetes and instrumental delivery have been reported. The various forms of PBPP, clinical findings and diagnostic measures are described. Recent evidence suggests that the natural history of PBPP is not all favourable, and residual deficits are estimated at 20% to 30%, in contrast with the previous optimistic view of full recovery in greater than 90% of affected children. There were no randomized controlled trials on nonoperative management. There was no conclusive evidence that primary surgical exploration of the brachial plexus supercedes conservative management for improved outcome. However, results from nonrandomized studies indicated that children with severe injuries do better with surgical repair. Secondary surgical reconstructions were inferior to primary intervention, but could still improve arm function in children with serious impairments.

CONCLUSIONS

It is not possible to predict which infants are at risk for PBPP, and therefore amenable to preventive measures. Twenty-five per cent of affected infants will experience permanent impairment and injury. If recovery is incomplete by the end of the first month, referral to a multidisciplinary team is necessary. Further research into prediction, prevention and best mode of treatment needs to be done.

Obstetric brachial plexus lesions: CT myelography

PURPOSE

To evaluate the value of computed tomographic (CT) myelography in the detection of root damage and differentiation of root avulsions from neurotmesis in a large cohort of patients with an obstetric brachial plexus lesion (OBPL).

MATERIALS AND METHODS

Institutional review board approval was obtained. Informed consent was waived by the medical ethics committee. One hundred eighteen patients with OBPL born in the cephalic position and six patients born in the breech position were selected for surgery by two neurosurgeons in a multidisciplinary team. Functional loss of the C5 through T1 innervated muscles was noted. All patients underwent preoperative CT myelography at an average age of 19 weeks. CT myelographic examination results were reviewed by two radiologists, who were blinded to the clinical findings, for the presence of root avulsions and pseudocysts. Interobserver agreement was assessed by calculating κ values.

RESULTS

CT myelographic results showed root avulsions in at least one level in 66 (56%) of 118 patients born in the cephalic position and in six (100%) of six patients born in the breech position. Levels C7 and C8 showed the most root avulsions, even if not expected from clinical examination results. A large number of root avulsions showed pseudocysts (73 [68%] of 107 levels in patients born in the cephalic position and 11 [73%] of 15 levels in patients born in the breech position).

CONCLUSION

CT myelographic results showed root avulsions in more than half of patients with OBPL. Root avulsions were even detected at levels that were not expected at clinical examination. Because root avulsions require specific reconstructive techniques, CT myelography is recommended for every preoperative patient with OBPL.

Electromyography, nerve action potential, and compound motor action potentials in obstetric brachial plexus lesions: validation in the absence of a "gold standard"

OBJECTIVE

Obstetric brachial plexus lesions (OBPLs) are caused by traction to the brachial plexus during labor. Typically, in these lesions, the nerves are usually not completely ruptured but form a "neuroma-in-continuity." Even in the most severe OBPL lesions, at least some axons will pass through this neuroma-in-continuity and reach the tubes distal to the lesion site. These axons may be particularly prone to abnormal branching and misrouting, which may explain the typical feature of co-contraction. An additional factor that may reduce functional regeneration is that improper central motor programming may occur. Surgery should be restricted to severe cases in which spontaneous restoration of function will not occur, i.e., in neurotmesis or root avulsions. A major problem is how to predict whether function will be best after spontaneous nerve outgrowth or after nerve reconstructive surgery. When a decision has been made to perform an early surgical exploration, what to do with the neuroma-in-continuity can be a problem. The intraoperative appraisal is difficult and depends on experience, but even in experienced hands, misjudgment can be made.

METHODS

We performed an observational study to assess whether early electromyography (at the age of 1 month) is able to predict severe lesions. Additionally, the value of intraoperative nerve action potential and compound motor action potentials was investigated.

RESULTS

Severe cases of OBPL can be identified at 1 month of age on the basis of clinical findings and needle electromyography of the biceps. This outcome needs independent validation, which is currently in progress. Nerve action potential and compound motor action potential recordings show statistically significant differences on the group level between avulsion, neurotmesis, axonotmesis, and normal. For the individual patient, a clinically useful cutoff point could not be found. Intraoperative nerve action potential and compound motor action potential recordings do not add to the decision making during surgery.

CONCLUSION

The absence of a "gold standard" for the assessment of the severity of the OBPL lesion makes prognostic studies of OBPL complex. The currently available assessment strategies used to obtain the best possible solutions are discussed.

Direct cord implantation in brachial plexus avulsions: revised technique using a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy

BACKGROUND

The superiority of a single stage combined anterior (first) posterior (second) approach and end-to-side side-to-side grafting neurorrhaphy in direct cord implantation was investigated as to providing adequate exposure to both the cervical cord and the brachial plexus, as to causing less tissue damage and as to being more extensible than current surgical approaches.

METHODS

The front and back of the neck, the front and back of the chest up to the midline and the whole affected upper limb were sterilized while the patient was in the lateral position; the patient was next turned into the supine position, the plexus explored anteriorly and the grafts were placed; the patient was then turned again into the lateral position, and a posterior cervical laminectomy was done. The grafts were retrieved posteriorly and side grafted to the anterior cord. Using this approach, 5 patients suffering from complete traumatic brachial plexus palsy, 4 adults and 1 obstetric case were operated upon and followed up for 2 years. 2 were C5,6 ruptures and C7,8T1 avulsions. 3 were C5,6,7,8T1 avulsions. C5,6 ruptures were grafted and all avulsions were cord implanted.

RESULTS

Surgery in complete avulsions led to Grade 4 improvement in shoulder abduction/flexion and elbow flexion. Cocontractions occurred between the lateral deltoid and biceps on active shoulder abduction. No cocontractions occurred after surgery in C5,6 ruptures and C7,8T1 avulsions, muscle power improvement extended into the forearm and hand; pain disappeared. LIMITATIONS INCLUDE: spontaneous recovery despite MRI appearance of avulsions, fallacies in determining intraoperative avulsions (wrong diagnosis, wrong level); small sample size; no controls rule out superiority of this technique versus other direct cord reimplantation techniques or other neurotization procedures; intra- and interobserver variability in testing muscle power and cocontractions.

CONCLUSION

Through providing proper exposure to the brachial plexus and to the cervical cord, the single stage combined anterior (first) and posterior (second) approach might stimulate brachial plexus surgeons to go more for direct cord implantation. In this study, it allowed for placing side grafts along an extensive donor recipient area by end-to-side, side-to-side grafting neurorrhaphy and thus improved results.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Spinal cord herniation into pseudomeningocele after traumatic nerve root avulsion: case report and review of the literature

We present an extremely rare case of traumatic spinal cord herniation due to a brachial plexus avulsion injury and provide a review of the literature of spinal cord herniation. Spinal cord herniation is an uncommon condition that can occur spontaneously or as a result of surgery or trauma. This condition often presents with symptoms and signs as Brown-Séquard syndrome. Traumatic pseudomeningoceles after a brachial plexus avulsion injury have been reported. But transdural herniation of the spinal cord into this pseudomeningocele is an extremely rare and poorly documented condition. There is only two reports of this condition in a thoracic case. The authors report the case of a 22-year-old man presented with a 2-year history of quadriplegia. He was involved in a motorcycle accident, 3 years prior to his presentation. Four years after the initial right brachial plexus injury, he was not able to walk independently. Magnetic resonance imaging (MRI) and computerized tomography (CT) myelography revealed a lateral pseudomeningocele arising from the right C6-7 and C7-T1 intervetebral foramen and cervical spinal cord herniation into this pseudomeningocele. The patient underwent primary closure of pseudomeningocele to prevent spinal cord reherniation. He can walk with cane and use left arm unrestrictedly at the 2-year follow-up examination. Spinal cord herniation following traumatic nerve root avulsion is extremely rare but it should be considered in the differential diagnosis of patients presenting with delayed myelopathy or Brown-Séquard syndrome.

Augmentation of partially regenerated nerves by end-to-side side-to-side grafting neurotization: experience based on eight late obstetric brachial plexus cases

OBJECTIVE

The effect of end-to-side neurotization of partially regenerated recipient nerves on improving motor power in late obstetric brachial plexus lesions, so-called nerve augmentation, was investigated.

METHODS

Eight cases aged 3-7 years were operated upon and followed up for 4 years (C5,6 rupture C7,8 T1 avulsion: 5; C5,6,7,8 rupture T1 avulsion: 1; C5,6,8 T1 rupture C7 avulsion: 1; C5,6,7 rupture C8 T1 compression: one 3 year presentation after former neurotization at 3 months). Grade 1-3 muscles were neurotized. Grade 0 muscles were neurotized, if the electromyogram showed scattered motor unit action potentials on voluntary contraction without interference pattern. Donor nerves included: the phrenic, accessory, descending and ascending loops of the ansa cervicalis, 3rd and 4th intercostals and contralateral C7.

RESULTS

Superior proximal to distal regeneration was observed firstly. Differential regeneration of muscles supplied by the same nerve was observed secondly (superior supraspinatus to infraspinatus regeneration). Differential regeneration of antagonistic muscles was observed thirdly (superior biceps to triceps and pronator teres to supinator recovery). Differential regeneration of fibres within the same muscle was observed fourthly (superior anterior and middle to posterior deltoid regeneration). Differential regeneration of muscles having different preoperative motor powers was noted fifthly; improvement to Grade 3 or more occurred more in Grade 2 than in Grade 0 or Grade 1 muscles. Improvements of cocontractions and of shoulder, forearm and wrist deformities were noted sixthly. The shoulder, elbow and hand scores improved in 4 cases.

LIMITATIONS

The sample size is small. Controls are necessary to rule out any natural improvement of the lesion. There is intra- and interobserver variability in testing muscle power and cocontractions.

CONCLUSION

Nerve augmentation improves cocontractions and muscle power in the biceps, pectoral muscles, supraspinatus, anterior and lateral deltoids, triceps and in Grade 2 or more forearm muscles. As it is less expected to improve infraspinatus power, it should be associated with a humeral derotation osteotomy and tendon transfer. Function to non improving Grade 0 or 1 forearm muscles should be restored by muscle transplantation.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Recovery of hand function following nerve grafting and transfer in obstetric brachial plexus lesions

OBJECT

Infants with obstetric brachial plexus lesions (OBPLs) commonly undergo surgical repair. Outcome data have been documented extensively for shoulder and biceps function, but information on hand function following nerve repair is limited. Hand function is impaired in approximately 15% of patients. The authors present a surgical strategy aimed primarily at restoration of hand function and analyze their methods and outcome to determine specific factors affecting functional recovery.

METHODS

Surgical strategy and outcome data were reviewed for 33 patients who underwent surgery for flail arm during a 10-year period. Nerve repair was performed at a mean age of 4.4 months. In 16 patients, the period of follow up (mean 50 months) was considered sufficiently long for final analysis. Of these 16 patients, 13 (Group 1) had complete discontinuity of the C-7, C-8, and T-1 spinal nerves. In three patients (Group 2), the C-8 and/or T-1 nerve was left in place because of shortage of nerve grafts or limited availability of proximal donor stumps. Postoperatively, a Raimondi hand function grade of 3 or higher was attained by nine of the 13 patients in Group 1 (69%) and one of the three patients in Group 2 (33%).

CONCLUSIONS

Useful hand function was restored in 69% of the patients in the presented series in whom reanimation of the hand could be fully attributed to the surgical reconstruction. The authors conclude that restoration of hand function should be the first goal of nerve repair in infants with a flail arm caused by an OBPL, but that the optimal strategy for different types of lesion remains to be determined.

External Rotation as a Result of Suprascapular Nerve Neurotization in Obstetric Brachial Plexus Lesions

OBJECTIVE:

Obstetric brachial plexus lesions may cause lifelong limitations of upper limb function. Nerve repair is widely advocated in infants who do not show spontaneous recovery. Typically, the suprascapular nerve (SSN) is involved in the lesion. Neurotization of the SSN routinely is performed, aiming at reinnervation of the infraspinatus muscle to restore external rotation. The results after SSN neurotization have not, as yet, been studied in detail; therefore, this study was undertaken. Of special interest was the comparison of two commonly applied SSN neurotization procedures: nerve grafting from C5 versus nerve transfer of the accessory nerve.

METHODS:

Infants with obstetric brachial plexus lesions after nerve grafting of C5 to the SSN (n = 65) or nerve transfer of the accessory nerve to the SSN (n = 21) were selected for retrospective analysis after a mean follow-up period of 3 years. Outcome was expressed in degrees of true glenohumeral external rotation. This was defined as the angle between the position of the 90 degrees (actively or passively) flexed elbow resting against the abdomen and the position of the flexed elbow after external rotation with the upper arm held in adduction by the investigator. This movement can be executed only by infraspinatus muscle contraction. In addition, functional external rotation was evaluated by testing the ability to reach the mouth and the back of the head.

RESULTS:

Only 17 (20%) of the 86 patients reached more than 20 degrees of external rotation, whereas 35 (41%) were unable to perform true external rotation. There was no statistically significant difference between nerve grafting from C5 and extraplexal nerve transfer using the accessory nerve. Functional scores showed that 88% can reach the mouth and that 75% can reach the head.

CONCLUSION:

The restoration of a fair range of true glenohumeral external rotation after neurotization of the SSN in infants with obstetric brachial plexus lesions, whether by grafting from C5 or by nerve transfer of the accessory nerve, is disappointingly low. However, it seems that compensatory techniques contribute to effectuate a considerable range of movement.

Birth injuries of the brachial plexus

Birth injuries of the brachial plexus are fairly common, but the majority of affected newborns make quick recoveries without any specific intervention. A minority suffer more severe injuries that lead to varying degrees of life-long disability. Happily, modern microsurgical techniques permit reconstruction of certain plexus injuries and, in carefully selected patients, can restore voluntary activity to target muscle groups. To what degree reanimation of paralyzed muscles improves function and quality of life for these children is a more important matter that has not yet been addressed at the level of modern standards of evidence. Brachial plexus reconstruction is only a first step in the multidisciplinary process needed to optimize long-term functional outcomes for severely affected infants.

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.

Birth injuries of the brachial plexus

Birth injuries of the brachial plexus are fairly common, but most affected newborns make quick recoveries without any specific intervention. A minority suffer more severe injuries that lead to varying degrees of life-long disability. Modem microsurgical techniques permit reconstruction of certain plexus injuries and, in carefully selected patients, can restore voluntary activity to target muscle groups. The degree to which reanimation of paralyzed muscles improves function and quality of life for these children is a more important matter that has not yet been addressed using modern standards of evidence. Brachial plexus reconstruction is only a first step in the multidisciplinary process needed to optimize long-term functional outcomes for severely affected infants.

Management of obstetrical brachial plexus palsy evaluation, prognosis, and primary surgical treatment

Primary surgery for obstetrical brachial plexus lesions is a young field of surgical expertise that offers the possibility of improved functional ability in carefully selected patients who would otherwise be faced with lifelong impairment and secondary skeletal deformities. One major challenge in this area of peripheral nerve surgery is the selection of patients most likely to derive benefit from surgical intervention. The key to the development of selection criteria and to the resolution of other considerations (such as the determination of root avulsion) is consistency, accuracy, and careful reporting of natural history and outcome data. In particular, we strongly feel that a statistically sound technique of assessment must be consistently applied from the time of presentation through long-term follow-up. Advancement to date has resulted from the application of evidence-based recommendations from large, well-designed, meticulous studies. As the field of obstetrical brachial plexopathy management continues to evolve, we can expect that questions will continue to be answered using such scientific methodology.