Motor nerve-conduction studies in obstetric brachial plexopathy for a selection of patients with a poor outcome

Predictors of Co-activation in Erb's Palsy: A Retrospective Study

Context

Three per thousand births have Erb's palsy. Spontaneous recovery is 50%. Co-activation yields poor outcomes. There are no objective indicators of its emergence.

Aims

Analyze if 1 month Axon Viability Index (AVI) of the axillary nerve and which active movement score (AMS) measures can predict co-activation.

Settings and Design

Tertiary level rehabilitation center, retrospective design.

Methods and Material

The electronic medical record (EMR) was reviewed for patients with Erb's palsy with Narakas grade 2 lesions, as having co-activation or not. The one-month Axillary AVI was used with monthly AMS scores. The inclusion criteria were an AVI greater than ten percent. Exclusion criteria were bi-brachial palsy, congenital anomalies, concomitant or subsequent neurological injuries, and orthopedic injuries.

Statistical Analysis Used

Descriptive statistics were used to calculate the median and interquartile values for AMS scores at each respective time point. Statistical significance for each time point was determined using a student's t-test.

Results

Regarding the t-test on the AVI data, a significant P value of 0.001 was found favoring the co-activation group. AVI of the Axillary nerve between 0.1 and 0.5 at 1 month is a reliable indicator of future development of co-activation. The following were strong indicators of the emergence of co-activation respectively: month three Wrist Extension in sitting, Shoulder Abduction in supine, Shoulder Abduction in sitting, Elbow Flexion in sitting, month six Elbow Flexion in sitting, month seven Elbow Flexion in sitting.

Conclusions

The axillary AVI at one month is a good predictor of future development of co-activation. The mentioned AMS items are the earliest indicators of co-activation.

A Systematic Review of the Tensile Biomechanical Properties of the Neonatal Brachial Plexus

Brachial plexus (BP) birth injury has a reported incidence of 1 to 4 per 1000 live births. During complicated deliveries, neonatal, maternal, and other birth-related factors can cause over-stretching or avulsion of the neonatal brachial plexus leading to injury. Understanding biomechanical responses of the neonate brachial plexus when subjected to stretch can offer insight into the injury outcomes while guiding the development of preventative maneuvers that can help reduce the occurrence of neonatal brachial plexus injuries. This review article aims to offer a comprehensive overview of existing literature reporting biomechanical responses of the brachial plexus, in both adults and neonates, when subjected to stretch. Despite the discrepancies in the reported biomechanical properties of the brachial plexus, available studies confirm the loading rate and loading direction dependency of the brachial plexus tissue. Future studies, possibly in vivo, that utilize clinically relevant neonatal large animal models can provide translational failure values of the biomechanical parameters for the neonatal brachial plexus when subjected to stretch.

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.

Anatomical study of the brachial plexus in human fetuses and its relation with neonatal upper limb paralysis

Objective

To study the anatomy of the brachial plexus in fetuses and to evaluate differences in morphology during evolution, or to find anatomical situations that can be identified as the cause of obstetric paralysis.

Methods

Nine fetuses (12 to 30 weeks of gestation) stored in formalin were used. The supraclavicular and infraclavicular parts of the brachial plexus were dissected.

Results

In its early course, the brachial plexus had a cord-like shape when it passed through the scalene hiatus. Origin of the phrenic nerve in the brachial plexus was observed in only one fetus. In the deep infraclavicular and retropectoralis minor spaces, the nerve fibers of the brachial plexus were distributed in the axilla and medial bicipital groove, where they formed the nerve endings.

Conclusion

The brachial plexus of human fetuses presents variations and relations with anatomical structures that must be considered during clinical and surgical procedures for neonatal paralysis of the upper limbs.

Outcomes from primary surgical reconstruction of neonatal brachial plexus palsy in 104 children

PURPOSE

The outcome from microsurgical reconstruction of neonatal brachial plexus palsy (NBPP) varies, and comparison between different series is difficult, given the differences in preoperative evaluation, surgical strategies, and outcome analysis. To evaluate our results, we reviewed a series of children who underwent surgical treatment in a period of 14 years.

METHODS

We made a retrospective review of 104 cases in which microsurgical repair of the brachial plexus was performed. Strength was graded using the Active Movement Scale. Whenever possible, upper palsies underwent surgery 4 to 6 months after birth and total lesions around 3 months. The lesions were repaired, according to the type of injury: neurolysis, nerve grafting, nerve transfer, or a combination of techniques. The children were followed for at least 24 months.

RESULTS

The majority of cases were complete lesions (56/53.8%). Erb's palsy was present in 10 cases (9.6%), and 39 infants (37.5%) presented an extended Erb's palsy. The surgical techniques applied were neurolysis (10.5%), nerve grafts (25.9%), nerve transfers (34.6%), and a combination of grafts and transfers (30.7%). The final outcome was considered poor in 41.3% of the cases, good in 34.3%, and excellent in 24%. A functional result (good plus excellent) was achieved in 58.3% of the cases.

CONCLUSIONS

There is no consensus regarding strategies for treatment of NBPP. Our surgical outcomes indicated a good general result comparing with the literature. However, our results were lower than the best results reported. Maybe the explanation is our much higher number of total palsy cases (53.8% vs. 25% in the literature).

Timing of rehabilitation in children with obstetric upper trunk brachial plexus palsy

OBJECTIVES

The initiation timing of rehabilitation in children with obstetric brachial plexus palsy is controversial. The aim of the present study is to evaluate the effectiveness of rehabilitation timing to the functional outcomes of patients with obstetric upper trunk brachial plexus palsy.

MATERIAL AND METHODS

Twenty-nine patients, who did not previously received any rehabilitation programme but attended our outpatient clinic, were included for the study. The electrophysiological findings, obstetric characteristics, and demographic features of the patients were recorded. The range of motion (ROM) of shoulders, elbows, and wrists and the strength of the muscles associated with these joints were evaluated. Modified Mallet Scale (MMS) was used for functional evaluation. A 4-week rehabilitation programme was performed twice at 2-month intervals. Patients were divided into three groups according to their ages as follows: 1-3 years old (group 1), 3-5 years old (group 2), and 5-7 years old (group 3). The ROMs, muscle strengths, and MMS scores of the patients were all evaluated.

RESULTS

Two out of 29 patients were female (6.9%) and 27 were male (93.1%). All 29 patients had right upper extremity palsy (100%). The MMS scores, ROMs, and muscle strength of the upper extremities had improved in all the groups following the standardized rehabilitation programme.

CONCLUSIONS

A rehabilitation programme is the best choice of treatment before surgical procedures in patients with mild to moderate obstetric upper trunk brachial plexus palsy regardless of age and the initiation time.

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.

Neonatal brachial plexus palsy--management and prognostic factors

Successful treatment of patients with neonatal brachial plexus palsy (NBPP) begins with a thorough understanding of the anatomy of the brachial plexus and of the pathophysiology of nerve injury via which the brachial plexus nerves stretched in the perinatal period manifest as a weak or paralyzed upper extremity in the newborn. NBPP can be classified by systems that can guide the prognosis and the management as these systems are based on the extent and severity of nerve injury, anatomy of nerve injury, and clinical presentation. Serial physical examinations, supplemented by a thorough maternal and perinatal history, are critical to the formulation of the treatment plan that relies upon occupational/physical therapy and rehabilitation management but may include nerve reconstruction and secondary musculoskeletal surgeries. Adjunctive imaging and electrodiagnostic studies provide additional information to guide prognosis and treatment. As research improves not only the technical aspects of NBPP treatment but also the ability to assess the activity and participation as well as body structure and function of NBPP patients, the functional outcomes for affected infants have an overall optimistic prognosis, with the majority recovering adequate functional use of the affected arm. Of importance are (i) early referral to interdisciplinary specialty clinics that can provide up-to-date advances in clinical care and (ii) increasing research/awareness of the psychosocial and patient-reported quality-of-life issues that surround the chronic disablement of NBPP.

A systematic review of evaluation methods for neonatal brachial plexus palsy: a review

OBJECT

Neonatal brachial plexus palsy (NBPP) affects 0.4-2.6 newborns per 1000 live births in the US. Many infants recover spontaneously, but for those without spontaneous recovery, nerve and/or secondary musculoskeletal reconstruction can restore function to the affected arm. This condition not only manifests in a paretic/paralyzed arm, but also affects the overall health and psychosocial condition of the children and their parents. Currently, measurement instruments for NBPP focus primarily on physical ability, with limited information regarding the effect of the disablement on activities of daily living and the child's psychosocial well-being. It is also difficult to assess and compare overall treatment efficacy among medical (conservative) or surgical management strategies without consistent use of evaluation instruments. The purpose of this study is to review the reported measurement evaluation methods for NBPP in an attempt to provide recommendations for future measurement usage and development.

METHODS

The authors systematically reviewed the literature published between January 1980 and February 2012 using multiple databases to search the keywords "brachial plexus" and "obstetric" or "pediatrics" or "neonatal" or "congenital." Original articles with primary patient outcomes were included in the data summary. Four types of evaluation methods (classification, diagnostics, physical assessment, and functional outcome) were distinguished among treatment management groups. Descriptive statistics and 1-way ANOVA were applied to compare the data summaries among specific groups.

RESULTS

Of 2836 articles initially identified, 307 were included in the analysis, with 198 articles (9646 patients) reporting results after surgical treatment, 70 articles (4434 patients) reporting results after medical treatment, and 39 articles (4247 patients) reporting results after combined surgical and medical treatment. Among medical practitioners who treat NBPP, there was equivalence in usage of classification, diagnostic, and physical assessment tools (that focused on the Body Function and Structures measure of the International Classification of Functioning, Disability, and Health [ICF]). However, there was discordance in the functional outcome measures that focus on ICF levels of Activity and Participation. Of the 126 reported evaluation methods, only a few (the Active Movement Scale, Toronto Scale Score, Mallet Scale, Assisting Hand Assessment, and Pediatric Outcomes Data Collection Instrument) are specifically validated for evaluating the NBPP population.

CONCLUSIONS

In this review, the authors demonstrate disparities in the use of NBPP evaluation instruments in the current literature. Additionally, valid and reliable evaluation instruments specifically for the NBPP population are significantly lacking, manifesting in difficulties with evaluating the overall impact and effectiveness of clinical treatments in a consistent and comparative manner, extending across the various subspecialties that are involved in the treatment of patients with NBPP. The authors suggest that all ICF domains should be considered, and future efforts should include consideration of spontaneous (not practitioner-elicited) use of the affected arm in activities of daily living with attention to the psychosocial impact of the disablement.

Needle electromyography at 1 month predicts paralysis of elbow flexion at 3 months in obstetric brachial plexus lesions

AIM

Treatment decisions in obstetric brachial plexus lesions are often based on clinical paralysis of elbow flexion at 3 months of age, when electromyography (EMG) is misleading because motor unit potentials (MUPs) occur in clinically paralytic muscles. We investigated whether EMG at 1 week or 1 month identifies infants with flexion paralysis at 3 months, allowing early referral.

METHOD

Forty-eight infants (27 females, 21 males) were prospectively studied. The presence or absence of flexion paralysis at around 1 week (median 9 d; range 5-17d), 1 month (median 31 d; range 24-53 d), and 3 months of age (median 87 d; range 77-106 d) was noted for clinical (shoulder external rotation, elbow flexion, extension, and supination) and EMG parameters (denervation activity, MUPs and polyphasic MUPs in the deltoid, biceps, and triceps muscles).

RESULTS

At 1 month, the absence of biceps MUPs had a sensitivity of 95% for later flexion paralysis, and absence of deltoid MUPs had a sensitivity of 100% for flexion paralysis; the false-positive rates for the same findings were 21% and 33% respectively. EMG at 3 months was highly misleading as MUPs were seen in 19 of 20 clinically paralytic biceps muscles.

INTERPRETATION

EMG at 1 month can identify severe cases of flexion paralysis for early referral EMG of the biceps at 3 months is highly misleading; the discrepancy between the EMG and clinical testing may be due to abnormal axonal branching and aberrant central motor control.