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

Brachial Plexus Birth Injury: A Review of Neurology Literature Assessing Variability and Current Recommendations

BACKGROUND

Publications regarding the epidemiology and management of brachial plexus birth injury (BPBI) were evaluated to investigate treatment guidelines for children with BPBI.

METHODS

A search of neurology literature from 1990 to 2019 was performed using PubMed, Scopus, and Medline. Data including incidence, risk factors, spontaneous recovery rates, imaging studies, treatment recommendations, and indications and timing for surgery were collected.

RESULTS

A total of 46 total studies were reviewed. Reported incidence rates for BPBI ranged from 0.3 to 3 per 1000 births. Spontaneous recovery rates had an average reported range from 66% to 75%. Physical and occupational therapy were recommended in 37% of articles. Computed tomographic myelogram and magnetic resonance imaging of the brachial plexus were the most commonly recommended imaging studies for BPBI. Timelines for surgical interventions ranged from age three to nine months. Early referral was recommended in 28% of the articles included in the review.

CONCLUSIONS

Given the inconsistencies in spontaneous recovery rates, imaging recommendations, and timing of referral, establishing consistent clinical guidelines for patients with BPBI is crucial for management. Early referral to specialists for evaluation and treatment may improve outcomes in children with BPBI.

Clinical, electrophysiological, and imaging findings in childhood brachial plexus injury

AIM

To assess the prognostic capabilities of various diagnostic modalities for childhood brachial plexus injuries (BPIs) and brachial plexus birth injury (BPBI) and postneonatal BPI.

METHOD

In this single-center retrospective cross-sectional study, we examined children with BPIs diagnosed or confirmed by electrodiagnostic studies between 2013 and 2020, and compared the prognostic value of various components of the electrophysiologic findings, magnetic resonance imaging (MRI) data, and the Active Movement Scale (AMS). We developed scoring systems for electrodiagnostic studies and MRI findings, including various components of nerve conduction studies and electromyography (EMG) for electrodiagnostic studies.

RESULTS

We identified 21 children (10 females and 11 males) aged 8 days to 21 years (mean 8y 6.95mo) who had a total of 30 electrodiagnostic studies, 14 brachial plexus MRI studies, and 10 surgical procedures. Among the diagnostic modalities assessed, brachial plexus MRI scores, EMG denervation scores, and mean total EMG scores were the most valuable in predicting surgical versus non-surgical outcomes. Correspondingly, a combined MRI/mean total EMG score provided prognostic value.

INTERPRETATION

Brachial plexus MRI scores and specific electrodiagnostic scores provide the most accurate prognostic information for children with BPI. Our grading scales can assist a multidisciplinary team in quantifying results of these studies and determining prognosis in this setting.

WHAT THIS PAPER ADDS

A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented. Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs). Composite electromyography scores have good prognostic value for childhood BPIs. Brachial plexus MRI has good prognostic value for childhood BPIs.

Application of magnetic resonance neurography in neonatal brachial plexus injury: A case report and literature review

Neonatal obstetric brachial plexus palsy is common in newborns with fetal macrosomia, especially those who are delivered vaginally with shoulder dystocia or breech delivery. The anatomical structure of brachial plexus in newborns is thin, and it is neither collinear nor coplanar in space; The location, the type and degree of neonatal brachial plexus injury need to be comprehensively judged by clinical history, neurological and imaging examination. Conventional MR imaging is not sufficient to diagnose brachial plexus injury. In this case report, we describe the clinical and imaging data of a newborn with brachial plexus injury diagnosed by the fat-suppressed T2-weighted sequence and MR myelography and confirmed by surgery. In addition, we review the related literature in an attempt to provide a better understanding of the principles and characteristics of neonatal brachial plexus injury diagnosed by magnetic resonance neurography.

Implications of median sensory study to the thumb and deltoid/biceps motor unit recruitment on identifying C6 root avulsion in upper neonatal brachial plexus palsy

INTRODUCTION/AIMS

Anatomic representation suggests that a median sensory nerve conduction study recording the thumb (median D1 NCS) may effectively assess upper neonatal brachial plexus palsy (NBPP). We sought to determine the feasibility of technique, establish reference data, and assess its ability to: (a) identify focal upper plexus lesions; and (b) identify C6 root avulsion. In a secondary analysis, we explored the association between absence/presence of motor unit action potentials (MUAPs) during needle electromyography (EMG) of the deltoid and biceps brachii muscles and C6 avulsion status.

METHODS

A retrospective chart review was performed of surgical patients with severe upper NBPP who ultimately underwent surgical reconstruction (between 2017 and 2020). Median D1 sensory nerve action potential (SNAP) amplitude ranges were determined in affected and contralateral limbs and analyzed by C6 root avulsion status. Also, presence/absence of MUAPs during EMG of the deltoid and biceps brachii was compared between C6 avulsion patients and controls.

RESULTS

Thirty-eight patients were included in our analysis. A median D1 NCS study was readily performed, showing a contralateral limb mean amplitude of 27.42 μV (range, 3.8-54.7 μV). Most patients had a low ipsilateral median D1 SNAP amplitude, regardless of C6 avulsion status. Detectable MUAPs in either deltoid or biceps brachii on EMG were atypical in C6 root avulsion.

DISCUSSION

The median D1 NCS identifies upper NBPP, but does not distinguish C6 avulsions from post-ganglionic lesions, likely due to the frequent co-occurrence of post-ganglionic axonal disruption. The presence of MUAPs on deltoid/biceps brachii EMG suggests C6 avulsion is unlikely.

A Systematic Review of the Electrodiagnostic Assessment of Neonatal Brachial Plexus

Despite improvements in obstetric care, neonatal brachial plexus palsy continues to significantly impact infants’ lives worldwide, with an incidence of 1 to 4 per 1000 live births. While a majority of affected infants recover spontaneously by three months, 20-30% suffer permanent functional deficits that significantly impair their quality of life. Anatomical complexity of the brachial plexus results in varying degrees of injury and pathological changes at multiple levels within the plexus. Current clinical diagnosis relies on electrodiagnostic techniques such as nerve conduction (i.e., motor and sensory) and electromyography studies. These techniques not only aid clinicians to differentiate between axonal and demyelinating lesions, evident by changes in signal shape and conduction, but also provide prognostic information in cases of brachial plexus injuries. The presented study offers a comprehensive review of existing literature on electrodiagnostic techniques employed for assessing neonatal brachial plexus injuries.