High spatial resolution electromyography and video-assisted movement analysis in children with obstetric brachial plexus palsy

Three-Dimensional Upper Limb Movement Analysis in Children and Adolescents With Brachial Plexus Birth Injury: A Systematic Review

BACKGROUND

To synthesize the current evidence on clinical use of three-dimensional upper limb movement analysis (3D-ULMA) in children and adolescents with brachial plexus birth injury (BPBI).

METHODS

MEDLINE, Embase, and Web of Science were searched for relevant studies up to April 2022. An automatic e-mail alert was installed to ensure no eligible article was missed. Articles evaluating 3D-ULMA in children and adolescents with BPBI were included. Covidence web-based platform was used for blind screening of eligible articles. Twenty-one observational studies with a final sample size of 609, encompassing 493 BPBI cases, met the inclusion criteria. Data were extracted using a custom form to support standardized extraction conforming to the Cochrane Checklist of items. Risk of bias was assessed using the Newcastle-Ottawa Scale, the Strengthening the Reporting of Observational Studies in Epidemiology checklist, and a specifically established quality assessment form for kinematic analysis studies.

RESULTS

Study setups differed, including six different types of kinematic devices. Twelve studies used the (modified) Mallet positions for their 3D-ULMA. Throughout the studies, 3D-ULMA was used for various purposes. The Newcastle-Ottawa Scale scored 16 articles with five stars or more, indicating fair to moderate quality.

CONCLUSIONS

This systematic review summarizes the different 3D-ULMA kinematic devices, test protocols, and their clinical use for BPBI. The use of 3D-ULMA provides valuable, objective, and quantified data to clinicians with regard to movement strategies; it complements existing clinical scales and can be implemented to evaluate effectiveness of therapy interventions. Implications for future research and clinical practice are discussed.

Assessment of upper extremity movement performance of patients with obstetric brachial plexus palsy

Coping strategies of patients with obstetric brachial plexus palsy (OBPP) are highly individual. Up to now, individual movement performance is assessed by visual observations of physicians or therapists - a procedure, which is highly subjective and lacks objective data. However, objective data about the individual movement performance are the key to evidence-based and individualized treatment. In this paper, a new approach is presented, which provides objective information about the upper extremity movement performance of patients with OBPP. The approach is based on the use of accelerometers in combination with a classification procedure. The movement performance of 10 healthy volunteers and 41 patients with OBPP has been evaluated by experienced physiotherapists and has been assigned to one of 4 categories representing the Mallet Scale (MS) IV to I. Three triaxial-accelerometers were placed at chest, upper arm and wrist of the affected side of the patient. Acceleration signals have been recorded during repetitive movements with relevance regarding daily life. Here, especially the results from the “hand to mouth” task are presented. From the 9 recorded acceleration signals 13 relevant features were extracted. For each of the 13 features 4 thresholds have been determined distinguishing best between the 4 patient categories of the MS and the healthy subjects. With respect to the thresholds each feature value has been assigned to the discrete numbers 0, 1, 2, 3 or 4. Afterwards, each discrete number has been weighted by a factor regarding the correlation between the feature’s value and the MS score. The resulting weighted discrete numbers of all 13 features have been added resulting in a score, which quantifies the individual upper extremity movement performance. Based on this score the movement performance of each patient has been assigned to the classes “very good”, “good”, “regular” and “bad”. All movements of the 10 healthy volunteers were classified as “very good”. The movement performance of two patients MS IV were classified as “very good” as well and the movements of the other 16 patients as “good”. The movements of the entire group of MS III patients fell into the class “regular”. Just one MS II patient was assigned to the class “regular” while the others were classified as “bad”. It was not possible to classify the movements of MS I patients. This was mainly due to the fact that none of these patients MS I was able to complete the task successfully. The developed approach demonstrated its ability to quantify the movement performance of upper extremity movements based on accelerometers. This provides an easy to use tool to assess patient’s movement strategies during daily tasks for diagnosis and rehabilitation.

Design of new multi-channel electrodes for surface electromyography signals for signal-processing

This paper covers the design aspects of a new multi-channel electrode for the acquisition of surface electromyography signals from a selected muscle. The new multi-channel electrode has 11 pins where the monopolar signals produced will be configured in a software either as Linear array or Laplacian configuration. The design specification of the pre-amplifier ideally was to have a voltage gain of 500 with bandpass filtering of 5 Hz-1 kHz. The final design of the pre-amplifier circuit using an INA 118 instrumentation amplifier was built and tested to give values for voltage gain of 484 with bandpass filtering of 6.8 Hz-1.02 kHz. The software configuration that gives clearer and more defined signals in terms of motor unit action potentials for future signal processing is the Laplacian rather than Linear array.

Upper Limb Multifactorial Movement Analysis in Brachial Plexus Birth Injury

Multifactorial motion analysis was first established for gait and then developed in the upper extremity. Recordings of infrared light reflecting sensitive passive markers in space, combined with surface eletromyographic recordings and/or transmitted forces, allow eclectic study of muscular coordination in the upper limb. Brachial plexus birth injury is responsible for various patterns of muscle weakness, imbalance, and/or simultaneous activation, soft tissue contractures, and bone-joint deformities, leading to individual motion patterns and adaptations, which we studied by means of motion analysis tools. We describe the technical development and examination setup to evaluate motion impairment and present first clinical results. Motion analysis is a reliable objective assessment tool allowing precise pre- and postoperative multimodal evaluation of upper limb function.

LEVEL OF EVIDENCE

II.

Obstetric brachial plexus palsy: treatment strategy, long-term results, and prognosis

BACKGROUND

Obstetric brachial plexus palsy is rare, but the limb impairments are manifold and often long-lasting. Physiotherapy, microsurgical nerve reconstruction, secondary joint corrections, and muscle transpositions are employed with success. The role of conservative and operative treatment options should be regularly reviewed.

METHODS

Selective literature review (evidence levels 3 and 4) and analysis of personal clinical operative and scientific experience over the past 15 years.

RESULTS

Children with upper and total plexus palsy displaying nerve root avulsions and/or -ruptures are treated today by early primary nerve reconstruction in the first few months of life followed by secondary corrections, with good functional results. The late complications, with muscle weakness, impaired motion patterns, and joint dysplasia, are often underrated.

CONCLUSIONS

The potential for scientific analysis is limited, due to the rarity and interindividual variability of the lesions and the varying effects on function and growth. Expectations and compliance are different in every patient. Surgical techniques are not yet standardized. Knowledge of the consequences for joint growth and congruence is inadequate. Today, functional improvement can be achieved by surgery in most clinical manifestations of obstetric brachial plexus palsy, within the framework of an interdisciplinary treatment concept.

Lyme disease--current state of knowledge

BACKGROUND

Lyme disease is the most frequent tick-borne infectious disease in Europe. The discovery of the causative pathogen Borrelia burgdorferi in 1982 opened the way for the firm diagnosis of diseases in several clinical disciplines and for causal antibiotic therapy. At the same time, speculation regarding links between Borrelia infection and a variety of nonspecific symptoms and disorders resulted in overdiagnosis and overtreatment of suspected Lyme disease.

METHOD

The authors conducted a selective review of the literature, including various national and international guidelines.

RESULTS

The spirochete Borrelia burgdorferi sensu lato is present in approximately 5% to 35% of sheep ticks (Ixodes ricinus) in Germany, depending on the region. In contrast to North America, different genospecies are found in Europe. The most frequent clinical manifestation of Borrelia infection is erythema migrans, followed by neuroborreliosis, arthritis, acrodermatitis chronica atrophicans, and lymphocytosis benigna cutis. Diagnosis is made on the basis of the clinical symptoms, and in stages II and III by detection of Borrelia-specific antibodies. In adults erythema migrans is treated with doxycycline, in children with amoxicillin. The standard treatment of neuroborreliosis is third-generation cephalosporins.

CONCLUSIONS

After appropriate antibiotic therapy, the outcome is favorable. In approximately 95% of cases neuroborreliosis is cured without long-term sequelae. When chronic borreliosis is suspected, other potential causes of the clinical syndrome must be painstakingly excluded.

Clinical applications of high-density surface EMG: A systematic review

High density-surface EMG (HD-sEMG) is a non-invasive technique to measure electrical muscle activity with multiple (more than two) closely spaced electrodes overlying a restricted area of the skin. Besides temporal activity HD-sEMG also allows spatial EMG activity to be recorded, thus expanding the possibilities to detect new muscle characteristics. Especially muscle fiber conduction velocity (MFCV) measurements and the evaluation of single motor unit (MU) characteristics come into view. This systematic review of the literature evaluates the clinical applications of HD-sEMG. Although beyond the scope of the present review, the search yielded a large number of "non-clinical" papers demonstrating that a considerable amount of work has been done and that significant technical progress has been made concerning the feasibility and optimization of HD-sEMG techniques. Twenty-nine clinical studies and four reviews of clinical applications of HD-sEMG were considered. The clinical studies concerned muscle fatigue, motor neuron diseases (MND), neuropathies, myopathies (mainly in patients with channelopathies), spontaneous muscle activity and MU firing rates. In principle, HD-sEMG allows pathological changes at the MU level to be detected, especially changes in neurogenic disorders and channelopathies. We additionally discuss several bioengineering aspects and future clinical applications of the technique and provide recommendations for further development and implementation of HD-sEMG as a clinical diagnostic tool.